Tropical Storm Warnings Flash Flood Watch
Elsa Moving Northeast Along The Coast
Weather in 5/Joe & Joe Weather Show Latest Podcast
Tropical Storm Warnings Flash Flood Watch Elsa Moving Northeast Along The Coast
Tropical Storm Elsa is moving through Eastern South Carolina and on a steady course north northeast. Elsa still remains a well defined entity and it appears that it will strengthen a bit once the center nears the coast. Part of the circulation is over the Southwest Atlantic which is the reason why it is still maintaining tropical storm strength. An approaching upper air trough might give it a little extra punch once i moves off the coast near the Delmarva Peninsula tonight.
..CENTER OF ELSA MOVES INTO SOUTHERN SOUTH CAROLINA…
…TROPICAL STORM WARNING ISSUED FOR PORTIONS OF THE MID-ATLANTIC
AND NEW ENGLAND STATES…
SUMMARY OF 500 AM EDT…0900 UTC…INFORMATION
ABOUT 90 MI…145 KM WNW OF CHARLESTON SOUTH CAROLINA
ABOUT 210 MI…335 KM WSW OF WILMINGTON NORTH CAROLINA
MAXIMUM SUSTAINED WINDS…40 MPH…65 KM/H
PRESENT MOVEMENT…NE OR 35 DEGREES AT 18 MPH…30 KM/H
MINIMUM CENTRAL PRESSURE…1007 MB…29.74 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
A Tropical Storm Warning is now in effect north of Great Egg Inlet,
New Jersey to Sandy Hook, New Jersey, and for the coast of Long
Island from East Rockaway Inlet to the eastern tip along the south
shore and from Port Jefferson Harbor eastward on the north shore. A
Tropical Storm Warning is also in effect from New Haven, Connecticut
to Merrimack River, Massachusetts including Cape Cod, Block Island,
Martha’s Vineyard, and Nantucket.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Warning is in effect for…
* Altamaha Sound, Georgia, 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
* New Haven, Connecticut to Merrimack River, Massachusetts including
Cape Cod, Block Island, Martha’s Vineyard, and Nantucket
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.
Nothing happens from Tropical Storm Elsa today into the first part of tonight. We are in a very warm and humid air mass and that is the kind of day we will see. There is a marginal risk for severe weather today as there could be some scattered thunderstorms that pop up here and there. Highs will be in the mid 80s to near 90 degrees. We can follow some of the scattered activity that is on the radars right now. On the regional radar the northern fringe of Elsa is just beginning to come into view.
Weather conditions will deteriorate tonight as Elsa moves northeast up the coast. The main threat time will be from midnight tonight until noon Friday. Flash Flood Watches are posted for most areas from Eastern Pennsylvania to Southern New England.
Rainfall forecasts are in a range of 2 to 3 inches in most places and there will be a narrow south north band that could wind up with more than 3 inches. Closer and east of the storm track rainfall will be a bit less. As storms move northward they usually change in character where the heavy rains shift to the west side and the stronger winds are to the east of the storm center.
There is also severe weather risk with Elsa and the Storm Prediction Center has a marginal risk of severe weather into Friday morning. Sometimes tropical systems can produce tornadoes and SPC is indicating a 2 percent risk. As far as winds are concerned I still think that this will be less of a problem. With the track along the coast and barely offshore, the strongest winds will remain over the ocean though some fringe gales could briefly develop along the immediate coast. Inland however it should not be an issue but if some strong convection develops there could be some wind gusts produced by severe thunderstorms.
The NAM forecast model loop above starts at 8pm tonight and ends at 2pm Friday. I think that the Nam is a little slow but it does I believe capture what this should look like from the standpoint of the radar presentation and the pressure field which would imply that winds are not a big issue with the strongest winds east of the low center.
WHAT TO EXPECT HUDSON VALLEY FLASH FLOOD WATCH IN EFFECT
Assuming a coastal slightly offshore track, the main impact will be rain from 1am to 11am Friday (give or take an hour or two) with some heavy downpours. Rainfall amounts here could also be in the 1 to 3 inch range with some locally higher amounts possible. Wind should not be a big issue though along the shores of Long Island Sound it could get gusty at times. After the rain ends, weather conditions should improve in the afternoon though another shower or thunderstorm going into the evening Friday can’t be ruled out.
WHAT TO EXPECT EASTERN SOUTHEASTERN, SOUTHCENTRAL PENNSYLVANIA
These areas will be on the western edge of the precipitation shield. Notice on the rainfall forecast map above that the one inch rainfall line cuts off sharply once you go west of the New Jersey Pennsylvania border. Rain arrives here around 8pm but there will be some thunderstorms that develop this afternoon and evening from the nearby frontal boundary. The rain shield clips this area overnight and it is done by morning. Note that if the track is a little further west then we will have to shift the heavier rain numbers westward but for now we are comfortable with what we have. Weather conditions improve Friday but there could be another round of showers and thunderstorms late in the day as a cold front and upper trough pass through.
WHAT TO EXPECT LONG ISLAND & SOUTH COASTAL CONNECTICUT
The forecast track will bring the center of Elsa very close to Long Island Friday morning. The big overhanging question is an upper trough over the Great Lakes and whether Elsa responds to that by strengthening a bit as it approaches. That is a tough call at this point. This will be a 6 to 8 hour event. Rain will be on the order of up to 2 inches or so and there could be some localized flooding where amounts are locally higher.
The period of time to watch will be from midnight Friday to noon Friday with the worst of it in the hours approaching daybreak until about 8 or 9am. Winds are a tougher call because that will depend on the track. If the low center passes to say NYC, we would be on the east side with likely less rain and more wind. If the center cuts Long Island in half then conditions will be different west of the low verses east. Also we don’t know how strong the low will be and if it doesn’t react to the upper trough over the Great Lakes, then we could see a weaker system that is more of a nuisance then anything else. Once Elsa goes by to our north weather conditions should improve Friday though another shower or thunderstorm is possible in the evening. Then we move a head to a warm and humid weekend with only a slight chance for a pop up downpour or thunderstorm each afternoon.
MANY THANKS TO TROPICAL TIDBITS & F5 WEATHER FOR THE USE OF MAPS
Please note that with regards to any severe weather, tropical storms, or hurricanes, should a storm be threatening, please consult your local National Weather Service office or your local government officials about what action you should be taking to protect life and property.