1WTNT41 KNHC 211756 2TCDAT1 3 4TROPICAL STORM OTTO SPECIAL DISCUSSION NUMBER 3 5NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 6100 PM EST MON NOV 21 2016 7 8This is a special advisory to report that Tropical Depression 9Sixteen has strengthened. Visible satellite imagery shows that the 10inner core has become better defined over the past few hours, and 11ASCAT data indicate that the maximum winds have increased to near 45 12kt. Additional intensification is expected, and Otto could become a 13hurricane in 48 hours, or sooner. 14 15No change has been made to the initial position or track forecast 16from the previous advisory. 17 18FORECAST POSITIONS AND MAX WINDS 19 20INIT 21/1800Z 11.5N 79.3W 45 KT 50 MPH 21 12H 22/0000Z 11.4N 79.4W 50 KT 60 MPH 22 24H 22/1200Z 11.3N 79.6W 55 KT 65 MPH 23 36H 23/0000Z 11.2N 80.3W 60 KT 70 MPH 24 48H 23/1200Z 11.1N 81.0W 65 KT 75 MPH 25 72H 24/1200Z 11.1N 82.6W 70 KT 80 MPH 26 96H 25/1200Z 11.1N 85.5W 35 KT 40 MPH...INLAND 27120H 26/1200Z 11.0N 88.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 28 29$$ 30Forecaster Pasch 31 32 33 34------------=_1479751012-1982-2035 35Content-Type: text/plain; charset="US-ASCII" 36Content-Disposition: inline 37Content-Transfer-Encoding: 7BIT 38 39= = = == = = 40WTNT41 KNHC 212038 41TCDAT1 42 43TROPICAL STORM OTTO DISCUSSION NUMBER 4 44NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 45400 PM EST MON NOV 21 2016 46 47Since the strengthening episode this morning, visible and microwave 48satellite imagery shows that Otto has not become much better 49organized. Maintenance issues have caused the cancellation of 50this afternoon's aerial reconnaissance mission. The initial 51intensity estimate is 45 kt based on data from an earlier 52scatterometer overpass, and above the latest Dvorak estimates from 53TAFB and SAB. The upper-level outflow is restricted over the 54southeastern quadrant of the circulation, probably due to continued 55south-southeasterly vertical shear. Strengthening to a hurricane 56seems likely, however, and the official intensity forecast is close 57to the model consensus. There remains a lot of uncertainty as to 58whether Otto will survive crossing Central America. The official 59forecast shows the system as a remnant low over the east Pacific, as 60suggested by the latest ECMWF and U.K. Met. office model runs. 61 62There has been little movement of the tropical cyclone today, while 63Otto remains in an environment of weak steering currents. The 64global models show a mid-level high pressure area gradually building 65to the north of the storm over the next several days. This should 66cause Otto to begin to move slowly westward within 48 hours, with a 67continued westward motion at a slightly faster forward speed in the 68latter part of the period. The official track forecast is close to 69a consensus of the latest GFS and ECMWF solutions. 70 71FORECAST POSITIONS AND MAX WINDS 72 73INIT 21/2100Z 11.3N 79.2W 45 KT 50 MPH 74 12H 22/0600Z 11.1N 79.4W 50 KT 60 MPH 75 24H 22/1800Z 11.1N 79.8W 55 KT 65 MPH 76 36H 23/0600Z 11.1N 80.4W 60 KT 70 MPH 77 48H 23/1800Z 11.1N 81.1W 65 KT 75 MPH 78 72H 24/1800Z 11.2N 83.1W 70 KT 80 MPH 79 96H 25/1800Z 11.2N 86.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 80120H 26/1800Z 11.2N 89.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 81 82$$ 83Forecaster Pasch 84 85 86 87------------=_1479760734-1982-2071 88Content-Type: text/plain; charset="US-ASCII" 89Content-Disposition: inline 90Content-Transfer-Encoding: 7BIT 91 92= = = == = = 93WTNT41 KNHC 220245 94TCDAT1 95 96TROPICAL STORM OTTO DISCUSSION NUMBER 5 97NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 981000 PM EST MON NOV 21 2016 99 100Deep convection continues to burst over the low-level center of 101Otto. A 2329 UTC WindSat microwave overpass shows that the 102inner-core structure of the small tropical cyclone has become 103better organized with a low-level ring feature now evident. 104Dvorak data T-numbers from SAB and TAFB have increased to 3.0 105and 3.5, respectively, and objective T-numbers from UW/CIMSS are 1063.2. These data support an initial wind speed of 50 kt, which 107could be somewhat conservative. 108 109The upper-level outflow remains well established over the western 110and northern portions of the circulation but it remains restricted 111to the southeast due to southeasterly shear of 15 to 20 kt. The 112shear is forecast to abate a little during the next couple of days 113while Otto traverses SSTs of around 29C. These conditions favor 114intensification and the NHC forecast is near a consensus of the 115SHIPS and LGEM models, and brings Otto to hurricane strength within 11636 hours. Although the NHC forecast does not indicate strengthening 117between 48 and 72 hours, Otto could become a little stronger after 11848 hours and before it moves inland over Central America in about 1193 days. After that time, uncertainty remains as to whether the 120tropical cyclone will survive its crossing of Central America. The 121NHC forecast continues to show the system as a remnant low over the 122eastern Pacific, which is supported by most of the global models. 123 124Center fixes from the microwave imagery indicate that Otto has 125been drifting southward this evening. The cyclone is not expected 126to move much overnight while it remains within an area of weak 127steering currents. On Tuesday, a mid-level ridge is forecast to 128begin building to the north of the storm and Otto is forecast to 129start moving slowly westward. The ridge is expected to remain in 130place during the remainder of the week and Otto should continue to 131move generally westward at a slightly faster pace. The new NHC 132track forecast is similar to the previous advisory, and lies between 133the latest GFS and ECMWF solutions, which is also near the most 134recent GFS ensemble mean. 135 136 137FORECAST POSITIONS AND MAX WINDS 138 139INIT 22/0300Z 10.9N 79.1W 50 KT 60 MPH 140 12H 22/1200Z 10.8N 79.3W 55 KT 65 MPH 141 24H 23/0000Z 10.9N 79.8W 60 KT 70 MPH 142 36H 23/1200Z 11.1N 80.7W 65 KT 75 MPH 143 48H 24/0000Z 11.3N 81.5W 70 KT 80 MPH 144 72H 25/0000Z 11.3N 84.0W 70 KT 80 MPH...INLAND 145 96H 26/0000Z 11.3N 87.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 146120H 27/0000Z 10.8N 90.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 147 148$$ 149Forecaster Brown 150 151 152 153------------=_1479782753-1982-2178 154Content-Type: text/plain; charset="US-ASCII" 155Content-Disposition: inline 156Content-Transfer-Encoding: 7BIT 157 158= = = == = = 159WTNT41 KNHC 220837 160TCDAT1 161 162TROPICAL STORM OTTO DISCUSSION NUMBER 6 163NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 164400 AM EST TUE NOV 22 2016 165 166Deep convection has continued to burst near the low-level center of 167Otto tonight. A pair of ASCAT passes between 02Z and 03Z showed 168peak winds of around 45 kt, which support maintaining the intensity 169at 50 kt for this advisory. This intensity estimate is also 170represents a blend of the 06Z subjective Dvorak estimates of 45 kt 171and the latest UW-CIMSS ADT estimate of 53 kt. An Air Force Reserve 172Hurricane Hunter aircraft is scheduled to investigate Otto later 173this morning. 174 175Otto's outflow pattern remains restricted south and southeast of the 176center, consistent with about 20 kt of shear analyzed over the 177cyclone by the SHIPS model analysis and UW-CIMSS. This shear is 178forecast to persist for the next 24 h or so and then abate somewhat 179by 36 hours. Given this, some gradual strengthening is expected 180while Otto moves over waters of around 29C, and the NHC forecast 181shows Otto becoming a hurricane in 24 to 36 h. The official 182forecast through 48 h is a little above the intensity consensus and 183close to the latest FSU Superensemble and the NOAA HFIP consensus 184aid HCCA. After that time, land interaction should result in 185weakening and much of the guidance continues to suggest that Otto 186will weaken to a remnant low after it emerges into the eastern 187Pacific, and this is still reflected in the official forecast. It 188is worth noting, however, that the ECMWF maintains Otto as a 189stronger cyclone over the Pacific through day 5. 190 191After drifting south-southeastward overnight, Otto is estimated to 192be stationary. Little net motion is expected today while the 193tropical cyclone is caught in a region of weak steering currents. By 19424 hours, a mid-level ridge will begin to build north of Otto, which 195should impart a west-northwestward motion and then a westward turn 196at a slightly faster forward speed by 48 h as the ridge amplifies. 197This synoptic pattern should steer Otto toward the coast of Central 198America in 48 to 72 hours. After that time, a further westward 199acceleration is expected as the mid-level ridge builds westward. 200The new NHC track forecast is faster than the previous one at 48 201hours and beyond and has been adjusted southward at days 3-5. The 202new official forecast lies between HCCA and the FSU Superensemble 203through 48 hours and is close to a blend of the GFS and ECMWF after 204that time. 205 206FORECAST POSITIONS AND MAX WINDS 207 208INIT 22/0900Z 10.7N 79.0W 50 KT 60 MPH 209 12H 22/1800Z 10.7N 79.1W 55 KT 65 MPH 210 24H 23/0600Z 10.9N 79.8W 60 KT 70 MPH 211 36H 23/1800Z 11.2N 80.8W 65 KT 75 MPH 212 48H 24/0600Z 11.2N 82.0W 70 KT 80 MPH 213 72H 25/0600Z 11.0N 85.2W 50 KT 60 MPH...INLAND 214 96H 26/0600Z 10.5N 89.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 215120H 27/0600Z 10.0N 93.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 216 217$$ 218Forecaster Brennan 219 220 221 222------------=_1479803877-1982-2246 223Content-Type: text/plain; charset="US-ASCII" 224Content-Disposition: inline 225Content-Transfer-Encoding: 7BIT 226 227= = = == = = 228WTNT41 KNHC 221442 229TCDAT1 230 231TROPICAL STORM OTTO DISCUSSION NUMBER 7 232NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 2331000 AM EST TUE NOV 22 2016 234 235Otto is close to becoming a hurricane. Satellite images indicate 236that the cloud pattern has become better organized, with a central 237dense overcast and broad band feature over the western semicircle 238evident. The past Air Force Reserve Hurricane Hunter flight 239recorded maximum flight-level winds of 65 kt, with SFMR winds of 240about 60 kt. Thus, the initial wind speed is increased to 60 kt 241for this advisory. 242 243Weak-to-moderate southeasterly shear is expected near Otto for the 244next couple of days while the tropical cyclone moves over warm 245water. These conditions should allow Otto to continue to 246strengthen, and almost all of the guidance has Otto as a hurricane 247before making a central American landfall. The official intensity 248forecast is raised from the previous one, and lies between the 249intensity consensus and the HWRF model. Land interaction will 250cause weakening after landfall, but a stronger Otto is less likely 251to dissipate as quickly over the eastern Pacific. Most of the 252guidance now keeps the storm going throughout the period, so the 253remnant low designation has been changed to a tropical cyclone 254status over the eastern Pacific. 255 256Otto really isn't moving much, with recon fixes showing little net 257motion during the morning hours. A mid-level ridge is forecast to 258build over the northwestern Caribbean Sea by tomorrow, which should 259cause Otto to move slowly westward. As the ridge builds, the 260forecast speed should increase, especially as the cyclone moves 261across the eastern Pacific. The guidance continues to trend 262southward, and the official forecast is shifted in that direction. 263 264 265FORECAST POSITIONS AND MAX WINDS 266 267INIT 22/1500Z 10.4N 79.2W 60 KT 70 MPH 268 12H 23/0000Z 10.4N 79.6W 65 KT 75 MPH 269 24H 23/1200Z 10.6N 80.6W 70 KT 80 MPH 270 36H 24/0000Z 10.8N 81.7W 75 KT 85 MPH 271 48H 24/1200Z 10.8N 82.8W 80 KT 90 MPH 272 72H 25/1200Z 10.5N 86.5W 45 KT 50 MPH 273 96H 26/1200Z 10.0N 90.5W 35 KT 40 MPH 274120H 27/1200Z 9.5N 94.5W 30 KT 35 MPH 275 276$$ 277Forecaster Blake 278 279 280 281------------=_1479825780-1982-2333 282Content-Type: text/plain; charset="US-ASCII" 283Content-Disposition: inline 284Content-Transfer-Encoding: 7BIT 285 286= = = == = = 287WTNT41 KNHC 222047 288TCDAT1 289 290HURRICANE OTTO DISCUSSION NUMBER 8 291NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 292400 PM EST TUE NOV 22 2016 293 294Satellite images indicate that Otto is continuing to strengthen. 295The overall satellite pattern has become more symmetric, with a 296large mass of intense convection near the center. Dvorak intensity 297estimates range from 65 to 77 kt, and the wind speed is set to 65 298kt, which makes Otto the seventh hurricane of the season. Otto 299is the latest hurricane formation on record in the Caribbean Sea, 300eclipsing the mark of Martha (1969) by about a day. 301 302Environmental conditions appear favorable for continued 303strengthening, with warm water and weak-to-moderate southeasterly 304shear during the next couple of days. Most of the guidance models 305show Otto making landfall as a category 1 hurricane on Thursday and 306so does the official forecast. Stronger shear, as well as land 307interaction over central America, will probably prevent Otto from 308restrengthening over the eastern Pacific. 309 310Satellite fixes suggest that Otto has been drifting westward during 311the day. A mid-level ridge is still forecast to build over the 312northwestern Caribbean Sea by tomorrow, which should cause Otto to 313move slowly to the west or west-northwest. As the ridge builds, the 314forward speed should increase, especially as the cyclone moves 315across the eastern Pacific and gradually loses latitude in that 316basin. The most notable change is that the guidance has come into 317better agreement on the track, although there are still some 318significant speed differences. Overall, the guidance envelope has 319shifted a bit to the north and is faster, and the official forecast 320follows that trend. 321 322A hurricane warning will likely be required tonight or early 323tomorrow for portions of Costa Rica and Nicaragua. 324 325FORECAST POSITIONS AND MAX WINDS 326 327INIT 22/2100Z 10.5N 79.6W 65 KT 75 MPH 328 12H 23/0600Z 10.6N 80.2W 70 KT 80 MPH 329 24H 23/1800Z 10.9N 81.1W 75 KT 85 MPH 330 36H 24/0600Z 11.0N 82.5W 80 KT 90 MPH 331 48H 24/1800Z 11.0N 83.9W 70 KT 80 MPH...INLAND 332 72H 25/1800Z 10.4N 88.2W 45 KT 50 MPH...OVER WATER 333 96H 26/1800Z 9.8N 91.9W 35 KT 40 MPH 334120H 27/1800Z 9.5N 96.0W 30 KT 35 MPH 335 336$$ 337Forecaster Blake/Pasch 338 339 340 341------------=_1479847654-1982-2429 342Content-Type: text/plain; charset="US-ASCII" 343Content-Disposition: inline 344Content-Transfer-Encoding: 7BIT 345 346= = = == = = 347WTNT41 KNHC 230245 348TCDAT1 349 350HURRICANE OTTO DISCUSSION NUMBER 9 351NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 3521000 PM EST TUE NOV 22 2016 353 354Reports from an Air Force Reserve Hurricane Hunter aircraft and 355satellite imagery indicate that the intensification of Otto has 356stopped since the last advisory. The aircraft reported a central 357pressure near 988 mb with flight-level and SFMR winds supporting, at 358best, an intensity of 65 kt. In addition, satellite imagery shows a 359decrease in the coverage of the associated convection. The 360arrested development might be due to dry air entrainment in the 361eastern semicircle as suggested by water vapor imagery and recent 362microwave overpasses. 363 364The initial motion is a somewhat uncertain 285/3. A mid- to 365upper-level ridge building over the northwestern Caribbean Sea and 366southeastern Mexico should steer Otto generally westward to 367west-northwestward for the next 36-48 hours, which would bring the 368center inland over southern Nicaragua or northern Costa Rica during 369that time. After 48 hours, the dynamical models forecast the ridge 370to build westward over the eastern Pacific Ocean and steer Otto 371westward or west-southwestward to the south of El Salvador, 372Guatemala, and eastern Mexico. The forecast guidance is in good 373agreement with the direction of the track, but there remains some 374spread in the forward speed. The new forecast track is again a 375little to the north and a little faster than the previous track, 376and it lies near the center of forecast guidance envelope. 377 378It is unclear how long the current arrested development will 379continue, as most of the intensity guidance forecasts strengthening 380before landfall. The new intensity forecast is based on the 381premise that intensification should resume after 12 hours and 382continue until landfall, with Otto forecast to make landfall as a 383category 1 hurricane. The cyclone should weaken significantly 384while crossing Central America, and as shown in the previous 385forecast strong shear should prevent re-intensification over the 386Pacific. 387 388The latest forecast track and wind radii require hurricane warnings 389for portions of the coasts of Costa Rica and Nicaragua at this time. 390 391 392FORECAST POSITIONS AND MAX WINDS 393 394INIT 23/0300Z 10.7N 79.8W 65 KT 75 MPH 395 12H 23/1200Z 10.8N 80.6W 65 KT 75 MPH 396 24H 24/0000Z 11.1N 81.8W 70 KT 80 MPH 397 36H 24/1200Z 11.2N 83.1W 75 KT 85 MPH 398 48H 25/0000Z 11.1N 84.8W 60 KT 70 MPH...INLAND 399 72H 26/0000Z 10.5N 89.5W 40 KT 45 MPH...OVER THE PACIFIC 400 96H 27/0000Z 10.0N 93.5W 35 KT 40 MPH 401120H 28/0000Z 10.0N 97.5W 30 KT 35 MPH 402 403$$ 404Forecaster Beven 405 406 407 408------------=_1479869185-1982-2503 409Content-Type: text/plain; charset="US-ASCII" 410Content-Disposition: inline 411Content-Transfer-Encoding: 7BIT 412 413= = = == = = 414WTNT41 KNHC 230838 415TCDAT1 416 417HURRICANE OTTO DISCUSSION NUMBER 10 418NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 419400 AM EST WED NOV 23 2016 420 421The satellite presentation of Otto has not changed much overnight, 422as deep convection continues to burst near the estimated center 423position in a small ragged CDO pattern. The latest Dvorak estimates 424are T4.0/65 kt from TAFB and SAB, and that will be the intensity 425for this advisory. An Air Force Reserve Hurricane Hunter aircraft 426is already en route to investigate Otto later this morning. 427 428Vertical shear, currently analyzed at 15-20 kt, should lessen a 429little bit in the next 12 to 24 h, but given the ragged nature of 430the system right now, only modest strengthening is expected before 431landfall. Weakening is then forecast through 48 hours while the 432center moves across Central America. Once Otto reaches the eastern 433Pacific, gradual weakening is expected to continue due to increasing 434shear and a drier atmospheric environment. In fact, the 00Z GFS 435and UKMET model runs both show the circulation of Otto dissipating 436in 4-5 days, and the NHC forecast now shows a remnant low by the end 437of the period. The new NHC intensity forecast is close to the 438SHIPS model through 72 hours and follows the weakening trend of the 439global models after that time. 440 441Otto is moving toward the west-northwest with an initial motion 442estimate of 290/04, although it has been difficult to pinpoint the 443center overnight. The mid-level ridge currently centered north of 444Otto will build westward and amplify during the forecast period. 445As a result, Otto should turn westward and accelerate in the short 446term, bringing the center to the coast in about 36 hours. Later in 447the period, a motion south of due west is indicated as the mid-level 448ridge amplifies over the eastern Pacific. The latest official 449forecast is slightly north of and slower than the previous one 450through landfall, and then has been adjusted southward and faster 451late in the period. The new NHC track is closest to the FSU 452Superensemble through 72 hours and is near a blend of the ECMWF 453and GFS after that time. 454 455Based on the latest forecast, tropical storm watches have been 456issued for portions of the Pacific coasts of Nicaragua and Costa 457Rica. 458 459FORECAST POSITIONS AND MAX WINDS 460 461INIT 23/0900Z 10.9N 80.4W 65 KT 75 MPH 462 12H 23/1800Z 11.1N 81.2W 65 KT 75 MPH 463 24H 24/0600Z 11.2N 82.3W 70 KT 80 MPH 464 36H 24/1800Z 11.3N 83.9W 65 KT 75 MPH...INLAND 465 48H 25/0600Z 11.0N 86.0W 45 KT 50 MPH...OVER WATER 466 72H 26/0600Z 10.0N 91.0W 40 KT 45 MPH 467 96H 27/0600Z 9.5N 96.0W 35 KT 40 MPH 468120H 28/0600Z 10.0N 100.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 469 470$$ 471Forecaster Brennan 472 473 474 475------------=_1479890343-1982-2588 476Content-Type: text/plain; charset="US-ASCII" 477Content-Disposition: inline 478Content-Transfer-Encoding: 7BIT 479 480= = = == = = 481WTNT41 KNHC 231438 482TCDAT1 483 484TROPICAL STORM OTTO DISCUSSION NUMBER 11 485NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 4861000 AM EST WED NOV 23 2016 487 488Otto has lost some organization since yesterday. The last Air 489Force Reserve reconnaissance mission reported that the eyewall has 490dissipated, along with a 6-mb rise in pressure. Still, the maximum 491700-mb flight-level winds were 68 kt, with SFMR winds of about 50 492kt. The initial intensity is conservatively reduced to 60 kt for 493this advisory. 494 495It appears that the southeasterly shear has been a little stronger 496than forecast yesterday, which has allowed some drier air to mix 497into the cyclone. This is evident in the inner-core data from the 498Air Force mission, which showed rather low dewpoints at 700 mb. The 499global models are suggesting the shear will decrease before 500landfall, and Otto should be moving over warmer waters later today 501that have not be subjected to any storm-forced upwelling. These 502factors suggest some restrengthening is possible overnight and 503Thursday, which is consistent with the bulk of the guidance models. 504Stronger shear over the eastern Pacific is expected to cause gradual 505weakening of Otto in that basin, with remnant low status likely by 506day 5. The official intensity forecast has been reduced somewhat 507from the last one but still calls for Otto to be a hurricane at 508landfall. 509 510Aircraft fixes show that Otto continues to move toward the 511west-northwest at 4 kt. A building mid-level ridge to the north of 512Otto should cause the tropical cyclone to turn westward and 513accelerate tonight. Late in the period, a motion south of due west 514is indicated as the mid-level ridge amplifies over the eastern 515Pacific. Model guidance is tightly clustered on this solution, and 516the latest official forecast is very close to the previous one. 517 518 519 520FORECAST POSITIONS AND MAX WINDS 521 522INIT 23/1500Z 11.1N 80.7W 60 KT 70 MPH 523 12H 24/0000Z 11.2N 81.5W 60 KT 70 MPH 524 24H 24/1200Z 11.3N 83.0W 65 KT 75 MPH 525 36H 25/0000Z 11.2N 84.7W 45 KT 50 MPH...INLAND 526 48H 25/1200Z 10.8N 87.0W 40 KT 45 MPH...OVER WATER 527 72H 26/1200Z 10.0N 92.0W 35 KT 40 MPH 528 96H 27/1200Z 9.5N 97.0W 30 KT 35 MPH 529120H 28/1200Z 10.0N 102.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 530 531$$ 532Forecaster Blake 533 534 535 536------------=_1479911945-1982-2660 537Content-Type: text/plain; charset="US-ASCII" 538Content-Disposition: inline 539Content-Transfer-Encoding: 7BIT 540 541= = = == = = 542WTNT41 KNHC 232042 543TCDAT1 544 545TROPICAL STORM OTTO DISCUSSION NUMBER 12 546NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 547400 PM EST WED NOV 23 2016 548 549There has not been much overall change to the Otto's satellite 550presentation today. While the convection temporarily weakened 551this morning, thunderstorm activity has rebuilt near the center 552during the afternoon. Satellite intensity estimates range from 55 553to 65 kt, so the initial wind speed will remain 60 kt. An Air Force 554Reserve Reconnaissance aircraft should be in Otto this evening to 555obtain a better estimate. 556 557The GFS and the ECMWF models continue to insist that shear near Otto 558should decrease this evening and tomorrow due to the nearby 559upper-level flow changing to a more easterly direction. Thus Otto 560still has the chance to become a hurricane again before landfall on 561Thursday, and the official forecast reflects this scenario. Otto 562should abruptly weaken after landfall, with a more gradual weakening 563anticipated over the eastern Pacific due to increasing easterly 564shear. The intensity guidance is showing a slower demise of Otto at 565long range, so the intensity forecast has been boosted slightly from 566the previous one at days 3 and 4. 567 568Otto is finally on the move, with the latest satellite fixes 569indicating a westward motion at about 6 kt. A strengthening 570mid-level ridge to the north of Otto should force the storm to move 571a bit faster to the west on Thursday, with an even faster 572south-of-west motion forecast over the weekend. Very few changes 573were required to the track prediction on this advisory since the 574model guidance remains in very good agreement. 575 576 577FORECAST POSITIONS AND MAX WINDS 578 579INIT 23/2100Z 11.2N 81.3W 60 KT 70 MPH 580 12H 24/0600Z 11.3N 82.3W 60 KT 70 MPH 581 24H 24/1800Z 11.2N 83.8W 65 KT 75 MPH 582 36H 25/0600Z 10.9N 85.8W 45 KT 50 MPH...INLAND 583 48H 25/1800Z 10.5N 88.0W 40 KT 45 MPH...OVER WATER 584 72H 26/1800Z 9.5N 92.5W 40 KT 45 MPH 585 96H 27/1800Z 9.5N 97.5W 35 KT 40 MPH 586120H 28/1800Z 10.5N 102.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 587 588$$ 589Forecaster Blake 590 591 592 593------------=_1479933761-1982-2789 594Content-Type: text/plain; charset="US-ASCII" 595Content-Disposition: inline 596Content-Transfer-Encoding: 7BIT 597 598= = = == = = 599WTNT41 KNHC 240234 600TCDAT1 601 602HURRICANE OTTO DISCUSSION NUMBER 13 603NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 6041000 PM EST WED NOV 23 2016 605 606A strong convective burst occurred near the center of Otto as an 607Air Force Reserve Hurricane Hunter aircraft investigated the 608cyclone near 0000 UTC. This resulted in the aircraft reporting 609central pressures near 977-979 mb, 850-mb flight-level winds in 610excess of 100 kt, and dropsondes supporting surface winds of at 611least 80 kt. However, these winds may have been associated with a 612transient mesocyclone in the strong convection, as data from a 613subsequent penetration showed a central pressure near 981 mb and 614lower winds. The initial intensity is now 75 kt based on 700-mb 615flight-level winds from the last aircraft pass, and there is a 616larger than normal uncertainty about this value. 617 618Conditions appear favorable for additional strengthening before the 619hurricane makes landfall over Central America on Thursday, and the 620intensity forecast shows modest strengthening for the first 12 621hours. Otto should weaken significantly while crossing southern 622Nicaragua and northern Costa Rica, and it is expected to emerge into 623the Pacific as a tropical storm between 24 and 36 hours. Strong 624easterly vertical shear should prevent re-intensification, and the 625new intensity forecast follows the trend of the previous forecast in 626showing a slow decay to a remnant low by 120 hours. However, it 627should be noted that the Pacific portion of the intensity forecast 628lies near the low end of the intensity guidance. 629 630Otto is moving a little faster with the initial motion now 275/8. 631The hurricane should make landfall over southern Nicaragua or 632northern Costa Rica sometime on Thursday. After landfall, a strong 633low- to mid-level ridge to the north should steer the cyclone 634westward to west-southwestward through 96 hours. Near the end of 635the forecast period, Otto or its remnants should approach the 636western end of the ridge and turn west-northwestward. The track 637guidance remains in good agreement, and the new forecast track is a 638slightly faster version of the previous track. 639 640 641FORECAST POSITIONS AND MAX WINDS 642 643INIT 24/0300Z 11.2N 82.2W 75 KT 85 MPH 644 12H 24/1200Z 11.2N 83.3W 80 KT 90 MPH 645 24H 25/0000Z 10.9N 85.2W 60 KT 70 MPH...INLAND 646 36H 25/1200Z 10.5N 87.4W 45 KT 50 MPH...OVER WATER 647 48H 26/0000Z 10.0N 89.5W 40 KT 45 MPH 648 72H 27/0000Z 9.5N 94.5W 40 KT 45 MPH 649 96H 28/0000Z 9.5N 99.0W 35 KT 40 MPH 650120H 29/0000Z 11.0N 103.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 651 652$$ 653Forecaster Beven 654 655 656 657------------=_1479954852-1982-2870 658Content-Type: text/plain; charset="US-ASCII" 659Content-Disposition: inline 660Content-Transfer-Encoding: 7BIT 661 662= = = == = = 663WTNT41 KNHC 240835 664TCDAT1 665 666HURRICANE OTTO DISCUSSION NUMBER 14 667NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 668400 AM EST THU NOV 24 2016 669 670Otto continues to produce an area of deep convection over the 671center, but it is difficult to tell if there have been any 672structural changes to the cyclone without microwave or aircraft data 673overnight. Dvorak estimates at 06Z were T4.5/77 kt from SAB and 674T4.0/65 kt from TAFB, with the 06Z UW-CIMSS ADT estimate at 72 kt. 675The initial intensity is held at 75 kt for this advisory based on 676the higher satellite estimates and continuity. An Air Force Reserve 677Hurricane Hunter aircraft will investigate Otto later this morning. 678 679There is an opportunity for some additional strengthening before 680Otto makes landfall in about 12 hours. After landfall, quick 681weakening is expected while the center moves across Central America, 682and Otto is expected to emerge into the eastern Pacific by 24 h as a 683tropical storm. Gradual weakening is forecast after that time, due 684to moderate to strong vertical shear, and this weakening trend is 685also shown in most of the global model guidance. The new NHC 686intensity forecast is similar to the previous one and near the low 687end of the TC intensity guidance late in the period. This forecast 688ends up closest to the FSU Superensemble by day 5, and shows Otto as 689a remnant low at that time. 690 691The initial motion estimate is 270/07, as Otto is under the steering 692influence of a mid-level ridge centered over Cuba and the Bahamas. 693As as mid/upper-level trough lifts out of the Gulf of Mexico, the 694ridge will build westward and amplify during the next 3-4 days. This 695pattern should result in an increase in forward speed and a motion 696somewhat south of due west for the next 72 hours. By the end of the 697period, Otto or its remnant low should turn west-northwestward as it 698rounds the western side of the weakening ridge. While there is 699general agreement on this scenario, there remains some spread in the 700track guidance. In particular, the latest ECMWF solution has shifted 701north and is slower than the rest of the guidance, especially 702compared to the GFS, which is faster and farther south. The new NHC 703track forecast is largely an update of the previous one but trends a 704little faster following the latest consensus. This track is close to 705the ECMWF/GFS blend at days 3 through 5. 706 707FORECAST POSITIONS AND MAX WINDS 708 709INIT 24/0900Z 11.2N 82.9W 75 KT 85 MPH 710 12H 24/1800Z 11.1N 83.9W 75 KT 85 MPH...INLAND 711 24H 25/0600Z 10.6N 86.2W 50 KT 60 MPH...OVER WATER 712 36H 25/1800Z 10.2N 88.4W 45 KT 50 MPH 713 48H 26/0600Z 9.8N 90.9W 40 KT 45 MPH 714 72H 27/0600Z 9.5N 96.5W 40 KT 45 MPH 715 96H 28/0600Z 10.0N 101.5W 35 KT 40 MPH 716120H 29/0600Z 11.5N 104.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 717 718$$ 719Forecaster Brennan 720 721 722 723------------=_1479976513-1982-2938 724Content-Type: text/plain; charset="US-ASCII" 725Content-Disposition: inline 726Content-Transfer-Encoding: 7BIT 727 728= = = == = = 729WTNT41 KNHC 241434 730TCDAT1 731 732HURRICANE OTTO DISCUSSION NUMBER 15 733NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 7341000 AM EST THU NOV 24 2016 735 736An Air Force Reserve Hurricane Hunter plane penetrated the eye of 737Otto around 1200 UTC this morning and indicated that the 738hurricane was intensifying. The estimated central pressure dropped 739to 976 mb and the flight-level wind at 700 mb peaked at 108 kt while 740the SFMR winds reached 90 kt. Since that time, satellite imagery 741showed that the hurricane cloud pattern has become better organized 742with a distinct eye in both convectional and microwave imagery, and 743the Data-T numbers reached 5.5 on the Dvorak scale. On this basis, 744the initial intensity has been set at 95 kt. 745 746There is an opportunity for some additional strengthening before 747Otto makes landfall during the next several hours. However, 748weakening should begin after the eye moves farther inland 749across Central America. Otto is expected to emerge over the 750eastern Pacific in about 12 to 24 h as a tropical storm. Otto should 751continue to weaken as it moves over the eastern pacific given that 752strong shear is forecast to prevail in that region, and the cyclone 753should become a remnant low by the end of the forecast period. The 754NHC intensity forecast is very similar to the previous one. 755 756Satellite and reconnaissance fixes indicate that Otto is moving 757toward the west or 270 degrees at 8 kt. The hurricane is 758trapped within easterly flow associated with a strong high 759pressure to the north, and since this high is forecast to persist, 760the hurricane should continue on a general west to west-southwest 761track for the next 3 days. After that time, a much weaker Otto 762should turn to the west-northwest around the western edge of 763the high. The track guidance is very consistent with this 764scenario and there is no need to deviate from the previous NHC 765forecast. The forecast track continues to be very close to the 766multi-model consensus. 767 768NHC thanks the crew of the Air Force Reserve Hurricane Hunters for 769flying and providing valuable data on Thanksgiving Day. 770 771 772FORECAST POSITIONS AND MAX WINDS 773 774INIT 24/1500Z 11.0N 83.4W 95 KT 110 MPH 775 12H 25/0000Z 10.8N 84.8W 60 KT 70 MPH...INLAND 776 24H 25/1200Z 10.3N 87.4W 50 KT 60 MPH...OVER WATER 777 36H 26/0000Z 9.8N 89.7W 40 KT 45 MPH 778 48H 26/1200Z 9.5N 92.5W 40 KT 45 MPH 779 72H 27/1200Z 9.0N 98.5W 40 KT 45 MPH 780 96H 28/1200Z 10.0N 102.5W 35 KT 40 MPH 781120H 29/1200Z 11.5N 104.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 782 783$$ 784Forecaster Avila 785 786 787 788------------=_1479998056-1982-3014 789Content-Type: text/plain; charset="US-ASCII" 790Content-Disposition: inline 791Content-Transfer-Encoding: 7BIT 792 793= = = == = = 794WTNT41 KNHC 242047 795TCDAT1 796 797HURRICANE OTTO DISCUSSION NUMBER 16 798NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 799400 PM EST THU NOV 24 2016 800 801Satellite imagery and radar data from Nicaragua indicate that 802Hurricane Otto made landfall at approximately 1800 UTC today along 803the extreme southern coast of Nicaragua, just north of the town 804of San Juan de Nicaragua. The peak intensity at the time of landfall 805was estimated to be at least 95 kt and the central pressure was 806estimated at 975 mb. This makes Otto the southernmost landfalling 807hurricane in Central America on record. 808 809The initial motion estimate is 270/10 kt. Otto is located inland 810over extreme southern Nicaragua, just north of the border with Costa 811Rica. Easterly steering flow on the south side of a deep-layer ridge 812located over the northwestern Caribbean Sea and southern Mexico is 813expected to keep Otto or its remnants moving in a westward to 814west-southwestward direction throughout the forecast period. The 815global and regional models are in good agreement on this track 816scenario, and only a slight northward adjustment was made to the 817previous forecast track, mainly due to the more northward initial 818position of Otto. 819 820Otto is forecast to weaken rapidly while the hurricane moves farther 821inland over the rough terrain of southern Nicaragua and northern 822Costa Rica tonight. Otto is expected to weaken to a tropical storm 823by the time it emerges over the eastern North Pacific in about 12 h, 824and maintain that intensity during the 24-96 hour period. The ECMWF, 825UKMET, and Canadian models continue to weaken Otto throughout the 826forecast period, especially after 48 hours when the cyclone is 827forecast to interact with a dry Gulf of Tehuantepec gap-wind event. 828Erosion of the inner-core convection and wind field is expected from 829this negative interaction, resulting in dissipation of Otto by 83048-72 h. In contrast, the GFS model keeps the gap-wind event away 831from Otto and strengthens the cyclone back to hurricane status by 83248 h and beyond. For now, the NHC official intensity forecast will 833remain similar to the previous advisory, and more closely follows 834the Decay-SHIPS intensity model, which is well below all of the 835other intensity forecast models. 836 837The primary threat from Otto is going to be torrential rainfall, 838which will result in dangerous flooding and mudslides. Reports of 839mudslides across northern Costa Rica have already been received from 840amateur radio operators in that area. 841 842FORECAST POSITIONS AND MAX WINDS 843 844INIT 24/2100Z 11.0N 84.3W 85 KT 100 MPH...INLAND 845 12H 25/0600Z 10.7N 86.0W 60 KT 70 MPH...OVER WATER 846 24H 25/1800Z 10.2N 88.5W 55 KT 65 MPH 847 36H 26/0600Z 9.8N 91.1W 45 KT 50 MPH 848 48H 26/1800Z 9.5N 93.9W 45 KT 50 MPH 849 72H 27/1800Z 9.4N 100.0W 45 KT 50 MPH 850 96H 28/1800Z 10.5N 103.5W 40 KT 45 MPH 851120H 29/1800Z 12.1N 105.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 852 853$$ 854Forecaster Stewart 855 856 857 858------------=_1480020465-1982-3098 859Content-Type: text/plain; charset="US-ASCII" 860Content-Disposition: inline 861Content-Transfer-Encoding: 7BIT 862 863= = = == = = 864WTNT41 KNHC 250254 865TCDAT1 866 867TROPICAL STORM OTTO DISCUSSION NUMBER 17 868NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 869900 PM CST THU NOV 24 2016 870 871Radar data from Las Nubes, Nicaragua, indicate that the core of Otto 872has remained well organized since landfall, with an eye still 873discernible. On the other hand, the convective clouds associated 874with the cyclone have warmed considerably since landfall. There 875have been no surface observations from the core, so the initial 876intensity is reduced to a somewhat uncertain 60 kt based on the 877decay in the satellite appearance. 878 879The initial motion estimate is 265/11. Otto is located over 880northwestern Costa Rica and should emerge into the Pacific during 881the next few hours. Easterly steering flow on the south side of a 882deep-layer ridge located over the northwestern Caribbean Sea and 883southern Mexico is expected to keep Otto moving in a westward to 884west-southwestward direction for the next 72 hours or so. After 885that time, the cyclone or its remnants are expected to reach the 886end of the ridge and turn northwestward. The new forecast track is 887similar to the previous track through 72 hours, then is shifted a 888little to the left of the track based on a shift in the consensus 889models. 890 891During the first 36 hours over the Pacific, Otto is likely to be 892over warm sea surface temperatures in an environment of moderate to 893strong easterly vertical wind shear. The intensity forecast during 894this time will show a slow weakening in agreement with the previous 895forecast due to the uncertainties in the strength of the shear. 896However, given the level of organization it would not be surprising 897if some intensification occurred. Around 48 hours, the cyclone is 898likely to encounter cooler sea surface temperatures which should 899cause a faster weakening. From 72-120 hours, Otto is expected to 900move over warmer water with decreasing shear at the same time it 901encounters a much drier air mass. The intensity forecast uses the 902premise that the dry air will cause the system to decay and thus 903calls for Otto to be a remnant low by 120 hours. It should be 904noted, though, the the intensity forecast after 48 hours remains 905near the lower edge of the guidance. 906 907The primary threat from Otto will continue to be torrential 908rainfall, which will result in dangerous flooding and mudslides. 909 910Since Otto has maintained itself as a tropical cyclone all the way 911across the land mass of Central America, based on National Weather 912Service and World Meteorological Organization protocols, it will 913retain the name Otto when it moves over the eastern Pacific in a few 914hours. Product headers will change to eastern Pacific headers 915beginning with the next complete advisory at 0900 UTC. The 916intermediate advisory at 0600 UTC will be issued under an Atlantic 917header. The ATCF identifier will change from AL162016 to EP222016 918at 0900 UTC. 919 920 921FORECAST POSITIONS AND MAX WINDS 922 923INIT 25/0300Z 10.9N 85.6W 60 KT 70 MPH...INLAND 924 12H 25/1200Z 10.5N 87.4W 55 KT 65 MPH...OVER THE PACIFIC 925 24H 26/0000Z 10.0N 90.0W 55 KT 65 MPH 926 36H 26/1200Z 9.6N 93.0W 50 KT 60 MPH 927 48H 27/0000Z 9.4N 96.0W 45 KT 50 MPH 928 72H 28/0000Z 9.5N 102.0W 45 KT 50 MPH 929 96H 29/0000Z 11.0N 105.0W 40 KT 45 MPH 930120H 30/0000Z 13.0N 106.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 931 932$$ 933Forecaster Beven 934 935 936 937------------=_1480042490-1982-3152 938Content-Type: text/plain; charset="US-ASCII" 939Content-Disposition: inline 940Content-Transfer-Encoding: 7BIT 941 942= = = == = = 943