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Tropical Storm NICOLE Forecast Discussion Number 7
2016-10-06 04:42:17| National Hurricane Center (Atlantic)
Issued at 1100 PM AST WED OCT 05 2016 000 WTNT45 KNHC 060241 TCDAT5 TROPICAL STORM NICOLE DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 1100 PM AST WED OCT 05 2016 Nicole has continued to become better organized during the past several hours with a warm spot appearing on the night visible images. The latest microwave data also show that the storm has maintained a mid-level eye, although the eye still isn't very well- defined in the low-level channels. Subjective Dvorak estimates range from 55 to 65 kt, so the initial intensity is raised to 60 kt. The storm is starting to take on a more asymetric appearance, a sign that the long-awaited shear might finally be starting to impact the cyclone. Still, the shear is not forecast to increase much over the next day or so, and Nicole has the opportunity to strengthen into a hurricane during that time, although not explicitly forecast below. Vertical wind shear should become rather strong by the end of the forecast period, and Nicole's winds should gradually decrease by early next week. It is a little puzzling that, with such strong shear in all of the global models, a lot of guidance don't show much weakening. Given the likelihood of such an unfavorable environment, the latest official forecast is very similar to the previous one, on the low side of the guidance closest to the LGEM model. The initial motion has turned to the right, now 320/8. Most of the guidance move the system to the north-northwest or north at a decreasing forward speed over the next 36 hours as a ridge collapses to the north of Nicole. After that time, northerly flow related to a trough over the central Atlantic is forecast to steer Nicole slowly southward for a couple of days. Up to about 72 hours, the model guidance is in reasonable agreement on this solution. Thereafter, the model spread becomes increasingly large very quickly, with a massive 1000 mile spread between the HWRF and the ECMWF models by day 5. This appears to be related to Nicole's possible interaction with Matthew and/or the southern portion of the trough, resulting in tracks primarily toward the southwest, west, or northeast. The latest long-range NHC forecast is very close to a blend of the GFS, UKMET and ECMWF ensemble means, with more weight on the ECMWF solution. This forecast shows a slow northward motion by the end of the period, ending up pretty close to the previous NHC prediction. FORECAST POSITIONS AND MAX WINDS INIT 06/0300Z 26.0N 64.1W 60 KT 70 MPH 12H 06/1200Z 26.9N 64.8W 60 KT 70 MPH 24H 07/0000Z 27.7N 65.3W 60 KT 70 MPH 36H 07/1200Z 27.8N 65.2W 55 KT 65 MPH 48H 08/0000Z 27.5N 64.5W 55 KT 65 MPH 72H 09/0000Z 26.5N 64.5W 55 KT 65 MPH 96H 10/0000Z 27.5N 65.5W 45 KT 50 MPH 120H 11/0000Z 29.0N 65.5W 35 KT 40 MPH $$ Forecaster Blake
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