Atlantic Basin Tropical Cyclones

Post-Tropical Cyclone Ian Forecast Discussion


000
WTNT44 KNHC 010840
TCDAT4

Post-Tropical Cyclone Ian Discussion Number  35
NWS National Hurricane Center Miami FL       AL092022
500 AM EDT Sat Oct 01 2022

Ian's circulation continues to wind down, and marine observations 
off the coast of North Carolina and Virginia, as well as earlier 
ASCAT data, indicate that maximum winds in the southerly flow south 
of the warm front have dropped below gale force.  The initial 
intensity is set at 30 kt for this advisory, with those winds 
occurring over the Atlantic waters.  The bulk of the associated 
rainfall is located north and west of the occluded/warm front, 
stretching from the southern Appalachians northward across the 
Mid-Atlantic states.

Ian's center has turned north-northwestward and slowed down over 
central North Carolina, with an initial motion of 345/10 kt.  The 
system is forecast to turn back to the north and slow down further 
later today, and global model fields indicate that the low center 
should dissipate over south-central Virginia by this evening.  
This is indicated in the new official forecast.  A new frontal 
low may form on the triple point over the Delmarva Peninsula or 
adjacent Atlantic waters and scoot eastward later today or tonight.

Although seas 12 feet or greater continue over portions of the 
adjacent Atlantic waters, they are not indicated in this forecast 
package since they are so far east of Ian's center.  Information on 
seas and high winds over marine areas can be found in High Seas
Forecasts issued by the National Weather Service...under AWIPS 
header NFDHSFAT1 and WMO header FZNT01 KWBC.

This is the last advisory on Ian issued by the National Hurricane 
Center.  Future information on this system can be found in Public 
Advisories issued by the Weather Prediction Center beginning at 11 
AM EDT, under AWIPS header TCPAT4, WMO header WTNT34 KWNH, and on 
the web at http://www.wpc.ncep.noaa.gov.


Key Messages:

1. Ongoing major to record river flooding will continue through 
next week across portions of central Florida. Limited flash, urban, 
and small stream flooding is possible across portions of the 
central Appalachians and the southern Mid-Atlantic this weekend.

2. Gusty winds are expected across portions of the central and 
southern Appalachians through this morning.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0900Z 35.7N  79.8W   30 KT  35 MPH...POST-TROP/EXTRATROP
 12H  01/1800Z 36.8N  79.6W   25 KT  30 MPH...POST-TROP/EXTRATROP
 24H  02/0600Z...DISSIPATED

$$
Forecaster Berg



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