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WTNT41 KNHC 231451

TCDAT1

 

Tropical Storm Ophelia Discussion Number   9

NWS National Hurricane Center Miami FL       AL162023

1100 AM EDT Sat Sep 23 2023

 

Since Ophelia made landfall earlier this morning, the tropical storm 

has maintained a healthy appearance in radar reflectivity from both 

the Morehead City and Raleigh radars, though the Doppler wind 

velocities have steadily decreased as it moves further inland. 

1-minute GOES-16 visible imagery depicts curved banding near the 

center of Ophelia, though the coldest cloud tops on infrared imagery 

have warmed from last night. The Doppler velocity data and surface 

observations suggest that maximum sustained winds are down to 45 kt 

this advisory, though this could be somewhat generous. However, 

Ophelia continues to produce a large swath of heavy rainfall both 

near and north of the current storm position, where a large region 

of Flood Watches and Warnings remain in effect.

 

The tropical storm appears to have accelerated this morning, with 

the latest estimated motion at 355/11 kt. Over the next 12-24 hours, 

Ophelia is expected to begin turning northeastward as it moves into 

southeastern Virginia by this evening. This motion should slow a bit 

as it becomes tangled up in a frontal boundary moving into the 

Delmarva Peninsula and off the mid-Atlantic coastline on Sunday. The 

track forecast this cycle is quite similar to the prior advisory, in 

best agreement with the simple and corrected track guidance.

 

Continued weakening is expected as Ophelia continues to move inland

across eastern North Carolina and then southeastern Virginia. On

Sunday, Ophelia's circulation is forecast to become increasingly

elongated as interacts with a pre-existing frontal boundary offshore

of the Mid-Atlantic coastline. Most of the model guidance shows

Ophelia merging with the baroclinic zone in about 24 hours, marking

its transition to an extratropical cyclone, with the low ultimately

being absorbed by the frontal zone in 48-60 h, though this could

occur sooner.

 

Key Messages:

 

1. Tropical storm conditions will continue along portions of the

southeastern and mid-Atlantic U.S. coasts within the Tropical Storm

Warning area today.

 

2. There is a danger of life-threatening storm surge inundation

over portions of eastern North Carolina and southeastern Virginia,

including Pamlico and Albemarle Sounds, the Neuse and Pamlico

Rivers, the lower James River, and the lower Chesapeake Bay, where

Storm Surge Warnings are in place.  Residents in these areas should

follow advice given by local officials.

 

3. Heavy rainfall from Ophelia may produce locally considerable 

flash, and urban flooding impacts across portions of the 

Mid-Atlantic states from North Carolina to New Jersey through 

Sunday.

 

4. Swells generated by this system will affect much of the U.S.

east coast through the weekend, likely causing life-threatening

surf and rip currents.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  23/1500Z 35.6N  77.2W   45 KT  50 MPH

 12H  24/0000Z 36.8N  77.3W   35 KT  40 MPH...INLAND

 24H  24/1200Z 38.2N  76.6W   30 KT  35 MPH...POST-TROP/EXTRATROP

 36H  25/0000Z 39.1N  75.1W   30 KT  35 MPH...POST-TROP/EXTRATROP

 48H  25/1200Z 39.3N  73.0W   25 KT  30 MPH...POST-TROP/EXTRATROP

 60H  26/0000Z...DISSIPATED

 

$$

Forecaster Papin