[Tropical] Tropical Cyclone Discussion

EMWIN Server emwin at nashvilleweather.net
Sun Sep 17 09:40:04 CDT 2023


WTNT45 KNHC 171439
TCDAT5

Tropical Storm Nigel Discussion Number   9
NWS National Hurricane Center Miami FL       AL152023
1100 AM AST Sun Sep 17 2023

Based on satellite imagery, Nigel appears to be steadily
strengthening. A prominent curved band of deep convection wraps
around the northern half of the tropical storm, with additional
convective activity recently observed very near its center.
Satellite intensity estimates range from around 45 to 55 kt, so the
initial intensity is set at a near-consensus value of 50 kt.

Nigel is in an environment that should support strengthening, and in
fact the SHIPS-RII and DTOPS rapid intensification models indicate
it has a near 50/50 chance of strengthening 25 kt in the next 24 h
and/or 55 kt in the next 48 h. Recent SSMIS imagery at 0911 UTC
indicated that the inner core of Nigel is probably not yet
well-enough developed to support immediate rapid intensification,
but that could happen at some point later today. Most of the
intensity models indicate that Nigel's intensity will peak in about
60 h, before increasing wind shear and cooler waters begin to affect
it. Extratropical transition should then begin in about 4 days, and
that process will likely be near complete at the end of the forecast
period. Only very small adjustments were made to the NHC intensity
forecast, which is very near the IVCN intensity consensus.

Likewise, nearly no changes were made to the official track
forecast. For the next 4-5 days, Nigel should generally move between
a ridge centered between Nigel and Margot, and a mid-latitude trough
that is forecast to move off the eastern coasts of the U.S. and
Canada early this week. These features will likely steer Nigel
generally northwestward for the next 2 days, and cause it to
accelerate northeastward after that. The NHC track forecast
continues to be based primarily on the HCCA and TVCN models.


FORECAST POSITIONS AND MAX WINDS

INIT  17/1500Z 24.0N  49.1W   50 KT  60 MPH
 12H  18/0000Z 25.3N  50.2W   60 KT  70 MPH
 24H  18/1200Z 26.8N  51.7W   75 KT  85 MPH
 36H  19/0000Z 28.2N  53.1W   85 KT 100 MPH
 48H  19/1200Z 29.8N  54.6W   95 KT 110 MPH
 60H  20/0000Z 31.8N  55.4W  100 KT 115 MPH
 72H  20/1200Z 34.2N  54.9W   95 KT 110 MPH
 96H  21/1200Z 39.6N  49.0W   85 KT 100 MPH
120H  22/1200Z 46.5N  35.5W   65 KT  75 MPH

$$
Forecaster D. Zelinsky
This weather bulletin was brought to you by:
www.nashvilleweather.net




More information about the Tropical mailing list