4 pm Update: Elsa Slightly Stronger; Headed for the Mid-Atlantic Coast

SUMMARY OF 4 PM CDT…2100 UTC…INFORMATION
LOCATION…36.3N 78.3W
ABOUT 125 MI…200 KM WSW OF NORFOLK VIRGINIA
ABOUT 300 MI…485 KM SW OF ATLANTIC CITY NEW JERSEY
MAXIMUM SUSTAINED WINDS…50 MPH…85 KM/H
PRESENT MOVEMENT…NE OR 40 DEGREES AT 21 MPH…33 KM/H
MINIMUM CENTRAL PRESSURE…1006 MB…29.71 INCHES

WATCHES AND WARNINGS
A Tropical Storm Warning is in effect for…
* Little River Inlet, South Carolina, to Sandy Hook, New Jersey
* Pamlico and Albemarle Sounds
* Chesapeake Bay south of North Beach and the tidal Potomac south of Cobb Island
* Delaware Bay south of Slaughter Beach
* Long Island from East Rockaway Inlet to the eastern tip along the south shore and from Port Jefferson Harbor eastward on the north shore
* New Haven, Connecticut to Merrimack River, Massachusetts including Cape Cod, Block Island, Martha’s Vineyard, and Nantucket

DISCUSSION AND OUTLOOK
A NOAA NOS observing site at Wrightsville Beach, North Carolina, recently reported a sustained wind of 41 kt, so Elsa’s maximum winds are now estimated to be 45 kt. A number of other observing sites in the vicinity have also reported sustained tropical-storm-force winds. Elsa’s slight strengthening may be the result of baroclinic forcing associated with an approaching short-wave trough. The system’s cloud tops have warmed somewhat during the day, but it is still producing some very heavy rains.

Elsa’s low-level center is a bit elongated from southwest to northeast, but surface synoptic data indicate that it has moved into northern North Carolina. The storm continues to gradually accelerate toward the northeast, and the initial motion estimate is 040/18 kt. A faster northeastward motion is expected over the next 1-2 days as the cyclone moves along with the mid-latitude southwesterly flow ahead of a broad mid-tropospheric trough over the eastern United States and Canada. Elsa should move near or over southeastern New England and Atlantic Canada within the next 24-48 hours. The official track forecast remains close to the previous one and similar to the multi-model consensus, TVCA.

The global models suggest that not much additional strengthening is likely. Simulated satellite imagery from these models show an extratropical appearance in 24-36 hours so the official forecast shows an extratropical transition by late Friday. This is also supported by cyclone phase analyses of the model fields from Florida State University.

KEY MESSAGES
1.As Elsa moves from North Carolina to Virginia today and this evening, heavy rainfall may result in limited flash and urban flooding. Heavy rainfall from the Mid-Atlantic into New England through Friday could lead to considerable flash and urban flooding.

2. Tropical storm conditions should continue along portions of the North Carolina coast this afternoon and spread over the mid-Atlantic coast later today or tonight. Tropical storm conditions are expected in portions of the southern New England states and New York by Friday. Gusty winds are expected over portions of Atlantic Canada Friday night and Saturday.

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Category: ALL POSTS, Severe Weather, Tropical