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Tropical Storm NICOLE Forecast Discussion Number 28
2016-10-11 04:37:56| National Hurricane Center (Atlantic)
Issued at 1100 PM AST MON OCT 10 2016 000 WTNT45 KNHC 110237 TCDAT5 TROPICAL STORM NICOLE DISCUSSION NUMBER 28 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 1100 PM AST MON OCT 10 2016 The vertical wind shear that has been hampering the development of Nicole has diminished during the past 6-12 hours. In response, the cyclone's convective pattern has become better organized and now is comprised of a curved band over the eastern semicircle. Satellite intensity estimates have not changed significantly since the last advisory, so the initial intensity remains 50 kt. The initial motion is now 350/5. During the next 12-24 hours, a mid-latitude shortwave trough currently seen in water vapor imagery north of Nicole is going to move eastward with a shortwave ridge taking its place north of the tropical cyclone. This should cause Nicole to turn northwestward for a time. After that, the ridge moves eastward in advance of a second mid-latitude trough moving eastward from the United States. This evolution should lead to Nicole turning northward and then northeastward with an increase in forward speed as it recurves into the westerlies. The forward motion may slow near the 120 hour time as Nicole becomes a large cut-off extratropical low over the northern Atlantic. The track guidance is in good agreement with this scenario, and the new track forecast is essentially an update of the previous track. The new forecast has the center of Nicole passing near or over Bermuda between 48 and 72 hours. Nicole is forecast to be in a light shear environment over increasing sea surface temperatures for the next 36-48 hours, and at the moment none of the low-level cooler air brought southward in the wake of Post-Tropical Cyclone Matthew is entraining into the system. However, water vapor imagery shows a lot of dry air just northwest of the tropical cyclone, and this could slow intensification in an otherwise favorable environment. After 48 hours, Nicole is likely to weaken due to increasing shear, although the dynamical models forecast increasing values of upper-level divergence that should slow the weakening. Extratropical transition is expected to occur at about 120 hours. The new intensity forecast is almost the same as the previous forecast and lies near the upper edge of the intensity guidance. FORECAST POSITIONS AND MAX WINDS INIT 11/0300Z 26.8N 65.5W 50 KT 60 MPH 12H 11/1200Z 27.4N 66.0W 55 KT 65 MPH 24H 12/0000Z 28.0N 66.6W 65 KT 75 MPH 36H 12/1200Z 28.9N 66.8W 70 KT 80 MPH 48H 13/0000Z 30.5N 66.3W 80 KT 90 MPH 72H 14/0000Z 34.5N 63.0W 80 KT 90 MPH 96H 15/0000Z 39.5N 57.0W 75 KT 85 MPH 120H 16/0000Z 42.0N 53.5W 70 KT 80 MPH...POST-TROP/EXTRATROP $$ Forecaster Beven
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