1WTNT43 KNHC 201455 2TCDAT3 3 4TROPICAL STORM LISA DISCUSSION NUMBER 4 5NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 61100 AM AST TUE SEP 20 2016 7 8The cloud pattern of the cyclone has steadily improved, with long 9curved bands having developed in the northern semicircle since the 10previous advisory. Although Dvorak satellite classifications from 11TAFB and SAB were 30 kt at 1200Z, recent UW-CIMSS ADT values have 12increased to 35 kt and AMSU intensity estimates range from 35-45 kt. 13Therefore the initial intensity has been increased to 35 kt, which 14is a compromise of these estimates, making the cyclone the eleventh 15named storm of the 2016 hurricane season. 16 17Visible satellite imagery indicates that Tropical Storm Lisa is now 18moving northwestward or 305/10 kt. Water vapor imagery and 19satellite-derived winds indicate that a large mid-latitude trough 20extends from near the Canary Islands southwestward into the tropics, 21which has created a break in the subtropical ridge along 30W-40W 22longitude. Lisa is forecast to move generally northwestward toward 23the break in the ridge for the next 4 days, followed by a northward 24turn as the cyclone moves around the western periphery of the ridge 25axis. The latest model guidance remains in good agreement on this 26track scenario, and the new NHC forecast track is just a little to 27the right of the previous advisory track, mainly to account for the 28more northward initial position, and lies close to the consensus 29model TVCN. 30 31Lisa has about 48 hours remaining to strengthen while the vertical 32wind shear and upper-level outflow pattern remain favorable, and 33sea-surface temperatures are above 27 deg C. However, a marginally 34moist mid-level environment and the large size of the cyclone are 35expected to prevent any rapid strengthening from occuring. After 36that time, the atmosphere is expected to become quite hostile, 37characterized by southwesterly shear of 25-30 kt and much drier 38mid-level air, resulting in steady weakening from 72-120 hours. 39Although the dynamical guidance continues to forecast some 40relaxation of the shear toward the end of the period, the cyclone 41will likely be too degraded to recover. The official intensity 42forecast is close to the SHIPS model through 48 hours, and then lies 43closer to the LGEM guidance after that. 44 45FORECAST POSITIONS AND MAX WINDS 46 47INIT 20/1500Z 15.3N 30.4W 35 KT 40 MPH 48 12H 21/0000Z 16.2N 31.5W 35 KT 40 MPH 49 24H 21/1200Z 17.3N 33.2W 40 KT 45 MPH 50 36H 22/0000Z 18.2N 35.0W 45 KT 50 MPH 51 48H 22/1200Z 19.1N 36.4W 50 KT 60 MPH 52 72H 23/1200Z 21.7N 39.0W 40 KT 45 MPH 53 96H 24/1200Z 24.5N 41.4W 30 KT 35 MPH 54120H 25/1200Z 28.3N 43.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 55 56$$ 57Forecaster Stewart 58 59 60 61------------=_1474383337-58484-2522 62Content-Type: text/plain; charset="US-ASCII" 63Content-Disposition: inline 64Content-Transfer-Encoding: 7BIT 65 66= = = == = = 67WTNT43 KNHC 201503 CCA 68TCDAT3 69 70TROPICAL STORM LISA DISCUSSION NUMBER 4...CORRECTED 71NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 721100 AM AST TUE SEP 20 2016 73 74CORRECTED LISA TO BE TWELFTH NAMED STORM 75 76The cloud pattern of the cyclone has steadily improved, with long 77curved bands having developed in the northern semicircle since the 78previous advisory. Although Dvorak satellite classifications from 79TAFB and SAB were 30 kt at 1200Z, recent UW-CIMSS ADT values have 80increased to 35 kt and AMSU intensity estimates range from 35-45 kt. 81Therefore the initial intensity has been increased to 35 kt, which 82is a compromise of these estimates, making the cyclone the twelfth 83named storm of the 2016 hurricane season. 84 85Visible satellite imagery indicates that Tropical Storm Lisa is now 86moving northwestward or 305/10 kt. Water vapor imagery and 87satellite-derived winds indicate that a large mid-latitude trough 88extends from near the Canary Islands southwestward into the tropics, 89which has created a break in the subtropical ridge along 30W-40W 90longitude. Lisa is forecast to move generally northwestward toward 91the break in the ridge for the next 4 days, followed by a northward 92turn as the cyclone moves around the western periphery of the ridge 93axis. The latest model guidance remains in good agreement on this 94track scenario, and the new NHC forecast track is just a little to 95the right of the previous advisory track, mainly to account for the 96more northward initial position, and lies close to the consensus 97model TVCN. 98 99Lisa has about 48 hours remaining to strengthen while the vertical 100wind shear and upper-level outflow pattern remain favorable, and 101sea-surface temperatures are above 27 deg C. However, a marginally 102moist mid-level environment and the large size of the cyclone are 103expected to prevent any rapid strengthening from occuring. After 104that time, the atmosphere is expected to become quite hostile, 105characterized by southwesterly shear of 25-30 kt and much drier 106mid-level air, resulting in steady weakening from 72-120 hours. 107Although the dynamical guidance continues to forecast some 108relaxation of the shear toward the end of the period, the cyclone 109will likely be too degraded to recover. The official intensity 110forecast is close to the SHIPS model through 48 hours, and then lies 111closer to the LGEM guidance after that. 112 113FORECAST POSITIONS AND MAX WINDS 114 115INIT 20/1500Z 15.3N 30.4W 35 KT 40 MPH 116 12H 21/0000Z 16.2N 31.5W 35 KT 40 MPH 117 24H 21/1200Z 17.3N 33.2W 40 KT 45 MPH 118 36H 22/0000Z 18.2N 35.0W 45 KT 50 MPH 119 48H 22/1200Z 19.1N 36.4W 50 KT 60 MPH 120 72H 23/1200Z 21.7N 39.0W 40 KT 45 MPH 121 96H 24/1200Z 24.5N 41.4W 30 KT 35 MPH 122120H 25/1200Z 28.3N 43.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 123 124$$ 125Forecaster Stewart 126 127 128 129------------=_1474383882-58484-2526 130Content-Type: text/plain; charset="US-ASCII" 131Content-Disposition: inline 132Content-Transfer-Encoding: 7BIT 133 134= = = == = = 135WTNT43 KNHC 202042 136TCDAT3 137 138TROPICAL STORM LISA DISCUSSION NUMBER 5 139NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 140500 PM AST TUE SEP 20 2016 141 142During the past six hours, a central dense overcast (CDO) feature 143has developed over and to the east of Lisa's low-level center. The 144upper-level outflow has also improved, albeit elongated northeast- 145to-southwest. The initial intensity has been increased to 40 kt, 146which is a blend of a Dvorak satellite intensity estimate of T2.5/35 147kt from TAFB, a UW-CIMSS ADT values of T2.9/43 kt, and a 1611Z AMSU 148estimate of 44 kt. 149 150The initial motion estimate is 315/10 kt. Lisa has made a jog to the 151right of the previous forecast track and model guidance, which is 152most likely due to the center reforming closer to the strongest 153convection. Other than shifting the forecast track to the right of 154the previous advisory track to account for the more eastward initial 155position, the forecast rationale remains unchanged. The latest NHC 156model guidance continues to indicate a steady northwestward motion 157for the next four days toward a break in the subtropical ridge 158between 30W-40W longitude. On day 5, Lisa is expected to move 159northward as the ridge erodes eastward. The new NHC forecast track 160lies down the middle of the tightly packed guidance envelope through 161day 4, and then follows a blend of the ECMWF and HWRF models on day 1625 since those models maintain the cyclone longer. 163 164Lisa has another 36 hours or so to strengthen some more before the 165large-scale environment becomes very unfavorable, which will be 166characterized by southwesterly vertical wind shear of 25-30 kt, 167drier and more stable air, and SSTs less than 27 deg C. It is 168possible that Lisa could end up being a little stronger between the 16924- and 36-hour forecast periods. By 48 hours, however, steady 170weakening is expected to ensue, with Lisa becoming a remnant low 171pressure system by 120 hours. The intensity forecast closely follows 172the intensity consensus model IVCN. 173 174FORECAST POSITIONS AND MAX WINDS 175 176INIT 20/2100Z 16.4N 31.0W 40 KT 45 MPH 177 12H 21/0600Z 17.2N 32.1W 45 KT 50 MPH 178 24H 21/1800Z 18.1N 33.6W 50 KT 60 MPH 179 36H 22/0600Z 19.0N 35.0W 50 KT 60 MPH 180 48H 22/1800Z 20.0N 36.5W 45 KT 50 MPH 181 72H 23/1800Z 22.7N 39.2W 35 KT 40 MPH 182 96H 24/1800Z 25.2N 42.0W 30 KT 35 MPH 183120H 25/1800Z 29.2N 44.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 184 185$$ 186Forecaster Stewart 187 188 189 190------------=_1474404190-58484-2612 191Content-Type: text/plain; charset="US-ASCII" 192Content-Disposition: inline 193Content-Transfer-Encoding: 7BIT 194 195= = = == = = 196WTNT43 KNHC 210241 197TCDAT3 198 199TROPICAL STORM LISA DISCUSSION NUMBER 6 200NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 2011100 PM AST TUE SEP 20 2016 202 203Deep convection has increased in coverage near and to the northeast 204of the center of Lisa this evening. Although the exact center has 205been difficult to pinpoint in infrared satellite images, it appears 206that it is located near the southwestern edge of the convection due 207to some southwesterly shear. Satellite intensity estimates still 208support a wind speed of around 40 kt, so the initial intensity is 209unchanged for this advisory. Lisa has about 24 hours over warm 210water and in a marginally conducive upper-level wind environment in 211which to strengthen. After that time, an upper-level low to Lisa's 212northwest is expected to produce strong southwesterly shear over 213the cyclone, which should cause weakening. As a result, the NHC 214intensity forecast calls for peak intensity in about 24 hours, 215followed by steady weakening thereafter. The official forecast is 216near the upper-end of the guidance at 24 hours, but is slightly 217lower than the consensus after that time. 218 219The somewhat uncertain initial motion estimate is 315/9 kt. The 220track forecast appears to be fairly straight forward as Lisa 221should continue moving northwestward during the next several 222days toward a break in the subtropical ridge. Late in the forecast 223period, the cyclone should turn northward ahead of a deepening mid- 224to upper-level trough over the west-central Atlantic. The dynamical 225models are in good agreement on this scenario, and the NHC forecast 226is near a blend of the typically better performing ECMWF and GFS 227models. 228 229FORECAST POSITIONS AND MAX WINDS 230 231INIT 21/0300Z 17.1N 31.7W 40 KT 45 MPH 232 12H 21/1200Z 17.8N 32.7W 45 KT 50 MPH 233 24H 22/0000Z 18.6N 34.0W 50 KT 60 MPH 234 36H 22/1200Z 19.4N 35.2W 45 KT 50 MPH 235 48H 23/0000Z 20.6N 36.7W 40 KT 45 MPH 236 72H 24/0000Z 23.6N 39.8W 30 KT 35 MPH 237 96H 25/0000Z 26.5N 42.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 238120H 26/0000Z 31.0N 43.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 239 240$$ 241Forecaster Brown 242 243 244 245------------=_1474425668-58484-2680 246Content-Type: text/plain; charset="US-ASCII" 247Content-Disposition: inline 248Content-Transfer-Encoding: 7BIT 249 250= = = == = = 251WTNT43 KNHC 210833 252TCDAT3 253 254TROPICAL STORM LISA DISCUSSION NUMBER 7 255NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 256500 AM AST WED SEP 21 2016 257 258Lisa's cloud pattern has gradually become better organized into a 259comma-like shape, although the system still appears to be somewhat 260elongated from southwest to northeast. Upper-level outflow 261remains weak over the southeastern quadrant of the circulation. 262Dvorak classifications from both TAFB and SAB yield an intensity 263estimate of 45 kt, and that value is used for the advisory. The 264storm has less than 24 hours before west-southwesterly shear 265associated with an upper-level trough near 40W-50W longitude becomes 266prohibitively large for strengthening. Therefore, some slight 267additional intensification could occur today, but beyond 24 hours 268Lisa is forecast to steadily weaken. By days 4-5, although the 269shear is predicted to weaken when Lisa moves under the trough axis, 270the cyclone should have been disrupted too much by the earlier 271hostile environment to make a recovery. The official forecast is 272close to the LGEM guidance through 48 hours and a little below that 273model thereafter. 274 275The center is not easy to locate and the initial motion is a rather 276uncertain 315/8 kt, which is partially based on continuity from 277earlier estimates. A weak mid-tropospheric ridge to the north and 278northeast of Lisa should maintain a generally northwestward motion 279through 72 hours or so. Later in the forecast period, an 280approaching trough in the westerlies, which is also expected to 281accelerate Karl to the northeast, should cause Lisa to turn 282northward over the eastern Atlantic. The official track forecast 283is similar to the previous one and is close to a consensus of the 284ECMWF, GFS, and UKMET global models. 285 286FORECAST POSITIONS AND MAX WINDS 287 288INIT 21/0900Z 17.5N 32.2W 45 KT 50 MPH 289 12H 21/1800Z 18.2N 33.2W 50 KT 60 MPH 290 24H 22/0600Z 19.1N 34.5W 50 KT 60 MPH 291 36H 22/1800Z 20.1N 35.9W 45 KT 50 MPH 292 48H 23/0600Z 21.3N 37.4W 40 KT 45 MPH 293 72H 24/0600Z 24.1N 40.4W 30 KT 35 MPH 294 96H 25/0600Z 27.5N 43.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 295120H 26/0600Z 32.5N 43.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 296 297$$ 298Forecaster Pasch 299 300 301 302------------=_1474446798-58484-2771 303Content-Type: text/plain; charset="US-ASCII" 304Content-Disposition: inline 305Content-Transfer-Encoding: 7BIT 306 307= = = == = = 308WTNT43 KNHC 211434 309TCDAT3 310 311TROPICAL STORM LISA DISCUSSION NUMBER 8 312NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 3131100 AM AST WED SEP 21 2016 314 315The cloud pattern of Lisa has not changed much since the previous 316advisory. A 0911 UTC SSMIS image suggested that the low-level 317center was located on the western edge of the central convection. 318The 12Z Dvorak Data-T numbers from SAB and TAFB decreased and a 319partial ASCAT-B pass from 1115 UTC only showed 30-35 kt winds in the 320northeastern quadrant. However, the initial intensity is held at 45 321kt given the lack of clear evidence of weakening and in agreement 322with the the latest Dvorak CI numbers of T3.0/45 kt. There is only 323a small opportunity for the cyclone to strengthen before the shear 324increases even further in 24 to 36 hours. Weakening is expected 325after that time, and later in the period, as the mid-level 326environment becomes quite dry, the cyclone should weaken to a 327remnant low. The new NHC intensity forecast is similar to the 328previous one and is near the middle of the guidance in the first 36 329hours and then is near or below the weaker LGEM solution after that 330time. 331 332The initial motion estimate is a somewhat uncertain 320/07, given 333the lack of confidence in the location of the center. Lisa will 334move northwestward during the next 72 hours into a weakness in the 335subtropical ridge over the eastern Atlantic, and then recurve into 336the mid-latitude westerlies on days 4 and 5. The global models are 337in generally good agreement on this scenario, with the ECMWF lying 338on the left side of the guidance cluster and the GFS shifting to the 339right this cycle. The new NHC track forecast is an update of the 340previous one but has been adjusted for the initial position and 341motion. This forecast is near a blend of the latest GFS and ECMWF 342tracks and is well to the left of the GFDL and HWRF models, which 343lie nearly 200 n mi east of the rest of the guidance at days 3 and 3444. 345 346FORECAST POSITIONS AND MAX WINDS 347 348INIT 21/1500Z 18.0N 32.5W 45 KT 50 MPH 349 12H 22/0000Z 18.6N 33.4W 50 KT 60 MPH 350 24H 22/1200Z 19.7N 34.9W 45 KT 50 MPH 351 36H 23/0000Z 20.9N 36.5W 45 KT 50 MPH 352 48H 23/1200Z 22.3N 38.0W 40 KT 45 MPH 353 72H 24/1200Z 25.0N 41.0W 30 KT 35 MPH 354 96H 25/1200Z 28.5N 43.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 355120H 26/1200Z 34.0N 41.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 356 357$$ 358Forecaster Brennan 359 360 361 362------------=_1474468491-1891-50 363Content-Type: text/plain; charset="US-ASCII" 364Content-Disposition: inline 365Content-Transfer-Encoding: 7BIT 366 367= = = == = = 368WTNT43 KNHC 212039 369TCDAT3 370 371TROPICAL STORM LISA DISCUSSION NUMBER 9 372NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 373500 PM AST WED SEP 21 2016 374 375Vertical wind shear of 15-20 kt continues to take a toll on Lisa. 376The coldest convective tops have moved farther east away from the 377estimated low-level center position today. Dvorak estimates were 378T2.5/3.0 from both TAFB and SAB at 18Z, and based on these, the 379initial intensity has been lowered to 40 kt for this advisory. Given 380that Lisa has struggled to maintain itself today, and that the SHIPS 381model shows the shear increasing to 30 kt in the next 18 to 24 382hours, there seems to be little opportunity left for the cyclone to 383strengthen. Given this, the new NHC intensity forecast holds Lisa 384at 40 kt through 24 hours and then shows gradual weakening to 385remnant low status in 3 to 4 days as the shear increases to near 40 386kt and the mid-level relative humidity drops below 30 percent. This 387forecast is closest to the SHIPS and LGEM statistical-dynamical 388models. 389 390An AMSR-2 pass from GCOM-W1 from around 1430Z provided some guidance 391on the center location, but it remains somewhat uncertain given the 392large spread in the satellite fixes. However, it does appear that 393the center is located a little to the east of previous estimates, 394and the initial motion is estimated to be 325/06. The track 395forecast scenario has not changed, as Lisa is expected to move 396northwestward into a weakness in the subtropical ridge and then 397recurve into the mid-latitude flow during the forecast period. 398Overall, the guidance envelope has shifted eastward this cycle, and 399given the eastward adjustment in the initial position, the NHC 400forecast has been shifted eastward by about a degree. The official 401forecast track is close to a blend of the GFS and ECMWF and lies to 402the left of multi-model consensus TVCN. 403 404FORECAST POSITIONS AND MAX WINDS 405 406INIT 21/2100Z 18.5N 32.5W 40 KT 45 MPH 407 12H 22/0600Z 19.4N 33.3W 40 KT 45 MPH 408 24H 22/1800Z 20.8N 34.7W 40 KT 45 MPH 409 36H 23/0600Z 22.1N 36.0W 35 KT 40 MPH 410 48H 23/1800Z 23.5N 37.2W 30 KT 35 MPH 411 72H 24/1800Z 26.0N 40.0W 30 KT 35 MPH 412 96H 25/1800Z 30.0N 41.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 413120H 26/1800Z 36.0N 38.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 414 415$$ 416Forecaster Brennan 417 418 419 420------------=_1474490351-1891-174 421Content-Type: text/plain; charset="US-ASCII" 422Content-Disposition: inline 423Content-Transfer-Encoding: 7BIT 424 425= = = == = = 426WTNT43 KNHC 220238 427TCDAT3 428 429TROPICAL STORM LISA DISCUSSION NUMBER 10 430NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 4311100 PM AST WED SEP 21 2016 432 433Lisa remains a sheared tropical cyclone. Deep convection has 434expanded in coverage this evening, but recent microwave imagery and 435ASCAT data indicate that the low-level center is located near 436the far western edge of the sharp gradient of cold cloud tops. The 437ASCAT pass did not cover much of the northeastern portion of the 438circulation, but it did detected a large area of 35 kt winds to the 439north and north-northeast of the center. Based on these data and 440satellite estimates of 35 and 45 kt, from SAB and TAFB respectively, 441the initial intensity remains 40 kt. Lisa is already located 442within an area of strong upper-level southwesterly winds to the 443southeast of a large upper-level low. During the next day or two 444the tropical storm is forecast to approach the cut-off low, which 445according to the SHIPS model will produce 30-40 kt of shear over 446Lisa. As a result, the tropical cyclone is expected to weaken 447and become a remnant low in about 3 days, and it could dissipate 448before the end of the foreast period. The new NHC intensity 449forecast essentially an update of the previous forecast and is in 450best agreement with the SHIPS and LGEM guidance. 451 452The microwave and ASCAT fixes suggest that Lisa is moving 453north-northwestward at about 6 kt, which is a little right of the 454previous forecasts. The cyclone is expected to move northwestward 455toward a weakness in the subtropical ridge currently between 30 456and 40W. Later in the period, an amplifying mid- to upper-level 457trough over the western Atlantic should cause Lisa or its remnants 458to turn northward and recurve into the mid-latitude westerlies by 459day 5. The track guidance is in fairly good agreement, and only 460a small eastward adjustment was required during the first 72 hours. 461The updated track prediction is very close to the latest multi-model 462consensus. 463 464FORECAST POSITIONS AND MAX WINDS 465 466INIT 22/0300Z 19.2N 32.8W 40 KT 45 MPH 467 12H 22/1200Z 20.2N 33.8W 40 KT 45 MPH 468 24H 23/0000Z 21.6N 35.2W 35 KT 40 MPH 469 36H 23/1200Z 23.0N 36.5W 30 KT 35 MPH 470 48H 24/0000Z 24.3N 37.8W 30 KT 35 MPH 471 72H 25/0000Z 26.7N 40.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 472 96H 26/0000Z 31.0N 41.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 473120H 27/0000Z 36.5N 37.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 474 475$$ 476Forecaster Brown 477 478 479 480------------=_1474511898-1891-289 481Content-Type: text/plain; charset="US-ASCII" 482Content-Disposition: inline 483Content-Transfer-Encoding: 7BIT 484 485= = = == = = 486WTNT43 KNHC 220840 487TCDAT3 488 489TROPICAL STORM LISA DISCUSSION NUMBER 11 490NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 491500 AM AST THU SEP 22 2016 492 493As anticipated, the southwesterly shear has been gradually 494increasing, and the center of Lisa is located on the western edge 495of an area of very deep convection convection. Based on the average 496of Dvorak estimates, the initial intensity is kept at 40 kt in this 497advisory. Given that the shear is forecast to increase further, and 498the fact that Lisa is heading for cooler waters, the NHC forecast 499calls for weakening. The cyclone is expected to become a remnant low 500in about 3 days, but this process could even occur much sooner. The 501intensity forecast is very similar to the previous one. 502 503The steering pattern has not changed, and Lisa is moving toward the 504northwest or 310 degrees around the western side of a weak 505subtropical ridge. This general track should continue for the next 5062 to 3 days until a large mid-latitude trough amplifies and force 507Lisa or its remnants to recurve. The NHC track forecast is an update 508of the previous one and follows very closely the multi-model 509consensus. 510 511 512FORECAST POSITIONS AND MAX WINDS 513 514INIT 22/0900Z 19.9N 34.0W 40 KT 45 MPH 515 12H 22/1800Z 20.9N 34.7W 35 KT 40 MPH 516 24H 23/0600Z 22.3N 36.0W 30 KT 35 MPH 517 36H 23/1800Z 23.6N 37.3W 30 KT 35 MPH 518 48H 24/0600Z 25.0N 38.5W 30 KT 35 MPH 519 72H 25/0600Z 27.5N 41.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 520 96H 26/0600Z 31.5N 40.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 521120H 27/0600Z 35.0N 38.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 522 523$$ 524Forecaster Avila 525 526 527 528------------=_1474533646-1891-391 529Content-Type: text/plain; charset="US-ASCII" 530Content-Disposition: inline 531Content-Transfer-Encoding: 7BIT 532 533= = = == = = 534WTNT43 KNHC 221435 535TCDAT3 536 537TROPICAL STORM LISA DISCUSSION NUMBER 12 538NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 5391100 AM AST THU SEP 22 2016 540 541An ASCAT-A pass from 1138Z showed that the center of Lisa is located 542near the southwestern edge of an area of bursting deep convection. 543The ASCAT data showed a cluster of 40-45 kt winds north of the 544center, so the initial intensity is set to 45 kt for this advisory, 545which is also in agreement with the latest Dvorak current intensity 546estimates of T3.0/45 kt from TAFB and SAB. The restrengthening 547appears to have occurred despite the shear increasing to 30-35 kt 548based on the SHIPS model analyses and satellite analyses from 549UW-CIMSS, and the upper-level outflow has improved somewhat during 550the past few hours. However, the separation between the convection 551and the low-level center appears to be increasing, and Lisa will be 552moving into a region of even stronger southwesterly shear in the 553next 24 hours, which should result in weakening. The shear is 554forecast to relax late in the period, but it is unlikely that Lisa 555will be able to recover and the cyclone is forecast to become a 556remnant low in 3 to 4 days. This is in agreement with the global 557models, which show the system decaying by that time. The new NHC 558intensity forecast is a little higher than the previous one given 559the higher initial intensity, and is closest to the statistical- 560dynamical SHIPS and LGEM models. 561 562Based on the ASCAT data and earlier microwave fixes, my best 563estimate of the initial motion is 310/06, as the cyclone appears to 564have slowed down some during the past few hours. The track forecast 565reasoning remains the same, however, with Lisa expected to move 566northwestward into a break in the subtropical ridge for the next 48 567hours. After that time, Lisa or its remnants should recurve ahead 568of a large mid-latitude trough. The new NHC track forecast is an 569update of the previous one through 72 hours and has been shifted a 570bit to the right at days 4 and 5 following the latest model guidance 571trends. There is a fair bit of along-track spread in the guidance 572late in the period, with the ECMWF much faster than the GFS and 573UKMET. The NHC forecast favors the slower solution, in agreement 574with the latest guidance from the Ocean Prediction Center. 575 576The initial and forecast 34-kt wind radii were adjusted based on 577the above-mentioned ASCAT data. 578 579FORECAST POSITIONS AND MAX WINDS 580 581INIT 22/1500Z 20.0N 34.0W 45 KT 50 MPH 582 12H 23/0000Z 21.1N 35.1W 45 KT 50 MPH 583 24H 23/1200Z 22.5N 36.4W 40 KT 45 MPH 584 36H 24/0000Z 23.8N 37.6W 35 KT 40 MPH 585 48H 24/1200Z 25.0N 39.0W 30 KT 35 MPH 586 72H 25/1200Z 28.0N 41.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 587 96H 26/1200Z 32.0N 39.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 588120H 27/1200Z 35.5N 37.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 589 590$$ 591Forecaster Brennan 592 593 594 595------------=_1474554958-1891-509 596Content-Type: text/plain; charset="US-ASCII" 597Content-Disposition: inline 598Content-Transfer-Encoding: 7BIT 599 600= = = == = = 601WTNT43 KNHC 222035 602TCDAT3 603 604TROPICAL STORM LISA DISCUSSION NUMBER 13 605NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 606500 PM AST THU SEP 22 2016 607 608Strong vertical shear from an upper-level low near 24N 40W continues 609to plague Lisa, with the low-level center located to the southwest 610of the deep convection as seen in a 1749Z SSMIS overpass. The 611initial intensity remains 45 kt based on the earlier ASCAT data and 612the latest Dvorak estimate from SAB. UW-CIMSS analysis shows that 613the shear is already over 40 kt and the SHIPS model shows it near or 614above this value for the next 36 hours, which should result in 615weakening. The official forecast follows that trend and is close to 616the latest SHIPS guidance through 48 hours. After that time, Lisa 617is expected to remain a 30-kt post-tropical cyclone through 5 days. 618Even though the shear diminishes in about 72 hours, the mid-level 619relative humidity remains below 50 percent, and it is assumed that 620Lisa will be too weak to take advantage of the lower shear. 621 622The initial motion estimate is 320/07. Lisa is expected to continue 623moving northwestward into a break in the subtropical ridge for the 624next 48 hours. Beyond that time, Lisa or its remnants should 625recurve ahead of a large mid-latitude trough. The new NHC track 626forecast is basically an update of the previous one and is along the 627eastern edge of the latest guidance envelope. There continues to be 628a fair bit of along-track spread in the guidance late in the period, 629with the GFS now faster than the other guidance. The NHC forecast 630has been adjusted a little faster this cycle but is slower than the 631GFS and close to the latest guidance from the Ocean Prediction 632Center. 633 634FORECAST POSITIONS AND MAX WINDS 635 636INIT 22/2100Z 20.7N 34.5W 45 KT 50 MPH 637 12H 23/0600Z 21.8N 35.6W 40 KT 45 MPH 638 24H 23/1800Z 23.2N 37.0W 35 KT 40 MPH 639 36H 24/0600Z 24.4N 38.5W 30 KT 35 MPH 640 48H 24/1800Z 25.6N 40.1W 30 KT 35 MPH 641 72H 25/1800Z 29.5N 41.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 642 96H 26/1800Z 34.0N 38.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 643120H 27/1800Z 42.5N 30.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 644 645$$ 646Forecaster Brennan 647 648 649 650------------=_1474576597-1891-650 651Content-Type: text/plain; charset="US-ASCII" 652Content-Disposition: inline 653Content-Transfer-Encoding: 7BIT 654 655= = = == = = 656WTNT43 KNHC 230238 657TCDAT3 658 659TROPICAL STORM LISA DISCUSSION NUMBER 14 660NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 6611100 PM AST THU SEP 22 2016 662 663Lisa continues to struggle in the face of strong deep-layer shear. 664Although the cyclone continues to pulsate convection, several 665microwave passes between 1900 and 2100 UTC indicate that the center 666has become somewhat more removed from the deepest convection since 667this afternoon. The initial intensity has been lowered to 40 kt, in 668line with decreased Dvorak estimates from TAFB and SAB. A 2344 UTC 669ASCAT-B pass missed the center of Lisa, but showed that 35 kt winds 670are present 100-150 nm NE of the presumed center. 671 672Lisa is forecast to remain in a high shear and increasingly dry 673environment, so further weakening seems inevitable. The main 674question is how quickly will the deep convection cease to exist. 675The GFS and HWRF both show mid- to upper-level dry air cutting over 676the circulation in about 36 to 48 hours, suggesting a complete lack 677of deep convection in those models at that time. The official 678forecast now calls for Lisa to become post tropical within 48 hours, 679before being absorbed by an approaching front after 96 hours. 680 681There is little change to the track forecast reasoning overall. 682Lisa continues to move toward the northwest, or 320 degrees, at a 683rather uncertain 8 kt. A lack of microwave or scatterometer data 684over the center since 2100 UTC has made the center difficult to 685locate and introduces some uncertainty to the forecast. Regardless, 686Lisa should continue moving northwestward around a low- to mid-level 687ridge, located east of the Azores, before recurving ahead of an 688approaching front. The first 48 hours of the forecast are near a 689consensus of the GFS and ECMWF models. The 72 and 96 hour points 690incorporate guidance from the Ocean Prediction Center. 691 692 693FORECAST POSITIONS AND MAX WINDS 694 695INIT 23/0300Z 21.3N 35.2W 40 KT 45 MPH 696 12H 23/1200Z 22.4N 36.3W 35 KT 40 MPH 697 24H 24/0000Z 23.6N 37.8W 30 KT 35 MPH 698 36H 24/1200Z 24.7N 39.3W 30 KT 35 MPH 699 48H 25/0000Z 26.2N 40.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 700 72H 26/0000Z 30.5N 41.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 701 96H 27/0000Z 35.5N 37.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 702120H 28/0000Z...ABSORBED 703 704$$ 705Forecaster Beven/Zelinsky 706 707 708 709------------=_1474598332-1891-774 710Content-Type: text/plain; charset="US-ASCII" 711Content-Disposition: inline 712Content-Transfer-Encoding: 7BIT 713 714= = = == = = 715WTNT43 KNHC 230855 716TCDAT3 717 718TROPICAL STORM LISA DISCUSSION NUMBER 15 719NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 720500 AM AST FRI SEP 23 2016 721 722The center of Lisa has become fully exposed due to strong shear, 723like so many Atlantic tropical cyclones in 2016. Some convection 724remains, although well away from the center, in the northern 725semicircle. The initial wind speed is reduced to 35 kt, which is on 726the high side of the latest Dvorak estimates. Very strong shear 727should cause further weakening, along with marginal SSTS and 728increasingly dry air aloft. Deep convection will likely be 729struggling in that environment within 24 hours, and the new forecast 730has Lisa becoming a remnant low in 36 hours. Most of the global 731models now show Lisa decaying to a trough in 3 to 4 days before it 732gets absorbed by a cold front, but either way it should be a weak 733system by then. 734 735Lisa continues moving northwestward at about 8 kt. A track toward 736the west-northwest or northwest is expected for the next couple of 737days while the system moves around the subtropical ridge. Afterward 738the post-tropical cyclone should turn northward as it gets caught up 739in southerly flow ahead of Karl. The guidance has shifted westward 740on this cycle, possibly due to a weaker Lisa being steered more by 741the low-level subtropical ridge. Thus, the official forecast 742is moved westward as well, near or just west of the model consensus. 743 744 745FORECAST POSITIONS AND MAX WINDS 746 747INIT 23/0900Z 21.8N 35.7W 35 KT 40 MPH 748 12H 23/1800Z 22.7N 36.8W 30 KT 35 MPH 749 24H 24/0600Z 23.6N 38.3W 30 KT 35 MPH 750 36H 24/1800Z 24.6N 40.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 751 48H 25/0600Z 26.1N 41.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 752 72H 26/0600Z 30.5N 42.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 753 96H 27/0600Z...DISSIPATED 754 755$$ 756Forecaster Blake 757 758 759 760------------=_1474620957-1891-879 761Content-Type: text/plain; charset="US-ASCII" 762Content-Disposition: inline 763Content-Transfer-Encoding: 7BIT 764 765= = = == = = 766WTNT43 KNHC 231434 767TCDAT3 768 769TROPICAL STORM LISA DISCUSSION NUMBER 16 770NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 7711100 AM AST FRI SEP 23 2016 772 773Lisa's center remains exposed to the southwest of the deep 774convection due to around 40 kt of southwesterly shear as analyzed by 775UW-CIMSS and the SHIPS model fields. The initial intensity remains 77635 kt based on the latest Dvorak estimate from TAFB, but this could 777be a little generous. 778 779Strong shear is expected to continue for the next 24 to 36 hours. 780This shear, in combination with a drying mid-level atmosphere and 781marginal SSTs, should result in weakening. Lisa is forecast to 782weaken to a tropical depression tonight, and become a remnant low in 78324 to 36 hours, as organized deep convection is expected to decay in 784the harsh environment. The remnant low of Lisa is forecast to open 785up into a trough in 3 to 4 days, in agreement with the latest GFS 786and ECMWF solutions. 787 788The initial motion estimate is 315/06. Lisa should continue moving 789generally northwestward around the subtropical ridge for the next 36 790hours. After that time, the decaying system should recurve ahead of 791a deep-layer trough moving across the northern Atlantic. The new 792NHC track forecast is close to the previous one through 24 hours and 793has been nudged westward at 36 and 48 hours following the latest 794trend in the guidance. This forecast is close to the multi-model 795consensus aid TVCN and the GEFS ensemble mean. 796 797FORECAST POSITIONS AND MAX WINDS 798 799INIT 23/1500Z 22.2N 36.3W 35 KT 40 MPH 800 12H 24/0000Z 23.1N 37.5W 30 KT 35 MPH 801 24H 24/1200Z 24.2N 39.5W 30 KT 35 MPH 802 36H 25/0000Z 25.4N 41.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 803 48H 25/1200Z 27.4N 42.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 804 72H 26/1200Z 31.5N 40.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 805 96H 27/1200Z...DISSIPATED 806 807$$ 808Forecaster Brennan 809 810 811 812------------=_1474641263-1891-961 813Content-Type: text/plain; charset="US-ASCII" 814Content-Disposition: inline 815Content-Transfer-Encoding: 7BIT 816 817= = = == = = 818WTNT43 KNHC 232033 819TCDAT3 820 821TROPICAL DEPRESSION LISA DISCUSSION NUMBER 17 822NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 823500 PM AST FRI SEP 23 2016 824 825All of the deep convection has been removed far from the center of 826Lisa by continued strong southwesterly shear of around 40 kt. The 827initial intensity has been lowered to 30 kt based on the latest 828Dvorak estimate from TAFB. At this point, with a combination of 829strong shear, marginal SSTs and a drying mid-level atmosphere, it 830seems unlikely that Lisa will regain organized deep convection, so 831remnant low status is now indicated by 24 hours. The weak cyclone 832should dissipate by 72 hours in fast southwesterly flow ahead of an 833approaching deep-layer trough. 834 835The initial motion has been rather slow today, and is currently 836estimated as 310/06. The increasingly shallow cyclone is expected 837to turn west-northwestward tonight and then recurve between 36 and 83848 hours as the deep-layer trough approaches from the west. The new 839NHC track forecast is a little to the left of the previous one after 84012 hours, reflecting a westward shift in the guidance that is 841probably responding to Lisa's weakening. This forecast is close to 842the middle of the guidance envelope and near the latest guidance 843from the Ocean Prediction Center. 844 845FORECAST POSITIONS AND MAX WINDS 846 847INIT 23/2100Z 22.5N 36.5W 30 KT 35 MPH 848 12H 24/0600Z 23.4N 38.0W 30 KT 35 MPH 849 24H 24/1800Z 24.4N 40.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 850 36H 25/0600Z 26.0N 42.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 851 48H 25/1800Z 27.9N 42.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 852 72H 26/1800Z...DISSIPATED 853 854$$ 855Forecaster Brennan 856 857 858 859------------=_1474662817-1891-1077 860Content-Type: text/plain; charset="US-ASCII" 861Content-Disposition: inline 862Content-Transfer-Encoding: 7BIT 863 864= = = == = = 865WTNT43 KNHC 240248 866TCDAT3 867 868TROPICAL DEPRESSION LISA DISCUSSION NUMBER 18 869NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 8701100 PM AST FRI SEP 23 2016 871 872Lisa continues to suffer from strong vertical wind shear. There has 873been no deep convection within 120 nm of the center for nearly 12 874hours now, though occasional bursts of convection have been noted a 875little farther than that to the north. A 2324 ASCAT-B pass showed 876several 35-kt wind vectors between the center and the convection 877farther to the north. Based on this new information, it is believed 878that Lisa was still a tropical storm at the time of the previous 879advisory and at 0000 UTC. Given the lack of deep convection since 880that time, the initial intensity has been held at 30 kt. Regardless 881of the maximum winds, the dynamical guidance all suggest that the 882strong shear and dry mid- and upper-level air will continue to 883suppress convection near the center, and Lisa is forecast to be 884declared post-tropical within 12 hours. The remnant circulation 885should last a day or two after that, before dissipating ahead of a 886deep-layer trough approaching from the west. 887 888The depression may finally be beginning to speed up, and the initial 889motion estimate is 315/07. The low-level remnants of Lisa are 890still forecast to move west-northwestward, with a gradual turn 891toward the north in a day or two while it moves around the periphery 892of the subtropical high centered near the Azores. The official 893forecast has again been nudged westward, but lies a little to the 894right of the model consensus. 895 896 897FORECAST POSITIONS AND MAX WINDS 898 899INIT 24/0300Z 23.2N 37.3W 30 KT 35 MPH 900 12H 24/1200Z 23.9N 38.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 901 24H 25/0000Z 25.0N 40.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 902 36H 25/1200Z 26.4N 42.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 903 48H 26/0000Z 28.8N 42.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 904 72H 27/0000Z...DISSIPATED 905 906$$ 907Forecaster Beven/Zelinsky 908 909 910 911------------=_1474685337-1891-1204 912Content-Type: text/plain; charset="US-ASCII" 913Content-Disposition: inline 914Content-Transfer-Encoding: 7BIT 915 916= = = == = = 917WTNT43 KNHC 240858 918TCDAT3 919 920TROPICAL DEPRESSION LISA DISCUSSION NUMBER 19 921NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 922500 AM AST SAT SEP 24 2016 923 924A strong burst of convection has recently formed in the northeastern 925quadrant of Lisa. Overall, however, the system looks less organized 926than it did yesterday, with the low-level circulation becoming 927elongated from north to south. The initial wind speed is held at 30 928kt in agreement with the TAFB satellite classification. Although 929there is only limited skill in forecasting deep convection, this 930burst is expected to be ephemeral due to strong shear and dry air 931aloft. Thus, Lisa is still forecast to be a remnant low by this 932evening. The global models show Lisa weakening and opening up into 933a trough within 2 days, and so will the NHC prediction. 934 935The initial motion is a bit faster than earlier, now 315/08. Lisa, 936or its remnants, are still forecast to move west-northwestward, 937with a gradual turn toward the north in a day or two while it moves 938around the periphery of the subtropical high centered near the 939Azores. The official forecast is close to the previous one and the 940model consensus. 941 942FORECAST POSITIONS AND MAX WINDS 943 944INIT 24/0900Z 23.8N 37.9W 30 KT 35 MPH 945 12H 24/1800Z 24.6N 39.3W 30 KT 35 MPH...POST-TROP/REMNT LOW 946 24H 25/0600Z 26.0N 41.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 947 36H 25/1800Z 28.0N 42.2W 20 KT 25 MPH...POST-TROP/REMNT LOW 948 48H 26/0600Z...DISSIPATED 949 950$$ 951Forecaster Blake 952 953 954 955------------=_1474707542-1891-1307 956Content-Type: text/plain; charset="US-ASCII" 957Content-Disposition: inline 958Content-Transfer-Encoding: 7BIT 959 960= = = == = = 961WTNT43 KNHC 241437 962TCDAT3 963 964TROPICAL STORM LISA DISCUSSION NUMBER 20 965NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 9661100 AM AST SAT SEP 24 2016 967 968The convective burst that occurred overnight has separated from the 969low-level center of Lisa and is now nearly dissipated. This leaves 970Lisa as a tight swirl of low-level clouds once again. An ASCAT-B 971pass around 1200 UTC indicated that maximum winds were close to 40 972kt, but given the degradation of the cloud pattern since the pass 973the initial wind speed is set at 35 kt. This makes Lisa a tropical 974storm again. Even though Lisa is a little stronger than estimated 975earlier, the intensity forecast is unchanged from the previous 976one. Continued strong shear and dry air should cause a gradual 977decay of the cyclone, and Lisa will likely become a remnant low by 978tonight. The models are in good agreement in showing the remnant 979low opening into a trough in 36 to 48 hours before it becomes 980absorbed by a cold front. 981 982Lisa is moving northwestward at 9 kt. A west-northwestward to 983northwestward motion at about the same speed is expected during the 984next 24 hours as Lisa remains steered by a high pressure system to 985its north. A motion more toward the north is forecast to occur on 986Sunday as the high shifts eastward to near the Azores. Only small 987adjustments were made to the previous NHC track prediction, and it 988lies close to a consensus of the GFS and ECMWF models. 989 990FORECAST POSITIONS AND MAX WINDS 991 992INIT 24/1500Z 24.7N 38.8W 35 KT 40 MPH 993 12H 25/0000Z 25.7N 40.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 994 24H 25/1200Z 27.4N 41.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 995 36H 26/0000Z 29.3N 42.1W 20 KT 25 MPH...POST-TROP/REMNT LOW 996 48H 26/1200Z...DISSIPATED 997 998$$ 999Forecaster Cangialosi 1000 1001 1002 1003------------=_1474727850-1891-1376 1004Content-Type: text/plain; charset="US-ASCII" 1005Content-Disposition: inline 1006Content-Transfer-Encoding: 7BIT 1007 1008= = = == = = 1009WTNT43 KNHC 242037 1010TCDAT3 1011 1012TROPICAL DEPRESSION LISA DISCUSSION NUMBER 21 1013NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 1014500 PM AST SAT SEP 24 2016 1015 1016Lisa has been devoid of thunderstorm activity since the convective 1017burst dissipated shortly after 1200 UTC. Assuming some additional 1018spin down since the ASCAT pass this morning, the initial wind speed 1019is lowered to 30 kt, making Lisa a tropical depression again. 1020Meteosat dust product images from the GOES-R Proving Ground indicate 1021that a plume of Saharan dust is approaching Lisa from the east. This 1022dry air combined with westerly shear should cause the depression to 1023degenerate to a remnant low by tonight and continue weakening during 1024the next day or two. The global models are in fair agreement in 1025showing the low opening into a trough in 36 to 48 hours before it 1026gets absorbed by a cold front. 1027 1028Lisa is moving northwestward at 10 kt. A gradual turn to the north 1029is expected during the next day or two while the high pressure 1030system to the north of Lisa shifts eastward. The NHC track forecast 1031is slightly to the left of the previous one, and is in best 1032agreement with the various consensus aids. 1033 1034FORECAST POSITIONS AND MAX WINDS 1035 1036INIT 24/2100Z 25.3N 39.7W 30 KT 35 MPH 1037 12H 25/0600Z 26.4N 41.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 1038 24H 25/1800Z 28.4N 42.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 1039 36H 26/0600Z 30.5N 42.4W 20 KT 25 MPH...POST-TROP/REMNT LOW 1040 48H 26/1800Z...DISSIPATED 1041 1042$$ 1043Forecaster Cangialosi 1044 1045 1046 1047------------=_1474749454-1891-1462 1048Content-Type: text/plain; charset="US-ASCII" 1049Content-Disposition: inline 1050Content-Transfer-Encoding: 7BIT 1051 1052= = = == = = 1053