...CENTER OF ISAIAS NEARING SOUTHEAST VIRGINIA...
...STRONG WINDS...HEAVY RAINFALL...AND THE THREAT OF TORNADOES WILL
SPREAD NORTHWARD ALONG THE MID-ATLANTIC COAST THIS MORNING...
SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...36.3N 77.5W
ABOUT 15 MI...25 KM SE OF ROANOKE RAPIDS NORTH CAROLINA
ABOUT 85 MI...135 KM WSW OF NORFOLK VIRGINIA
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 28 MPH...44 KM/H
MINIMUM CENTRAL PRESSURE...993 MB...29.33 INCHES
Maximum sustained winds are near 70 mph (110 km/h) with higher
gusts. Only gradual weakening is anticipated while Isaias moves
north-northeastward near the mid-Atlantic coast today. A faster
rate of weakening is expected to begin tonight, and the system is
forecast to become post-tropical tonight or early Wednesday.
Tropical-storm-force winds extend outward up to 140 miles (220 km)
from the center. Sustained winds of 48 mph (78 km/h) and a gust to
63 mph (102 km/h) was recently reported at Duck, North Carolina.
Sustained winds of 39 mph (63 km/h) and a gust to 56 mph (91 km/h)
were also reported at Poquoson, Virginia.
Pink outline is for Tornado Watches.
Red boxes are Tornado warnings. Looks like most of them are north of the center.
Quote:
Tropical Storm Isaias Discussion Number 29
NWS National Hurricane Center Miami FL AL092020
500 AM EDT Tue Aug 04 2020
Isaias made landfall near Ocean Isle Beach, North Carolina, a few
minutes after the previous advisory package was issued. Since
that time, the center of Isaias has been moving quickly
north-northeastward across eastern North Carolina. Now that the
inner core of Isaias has moved inland, the peak surface winds have
decreased despite Doppler radar data still showing an area of
75-85 kt winds aloft. The latest surface observations indicated
that strong winds are occuring over the North Carolina Sounds and
Outer Banks. Based on a blend of the available data, the initial
wind speed is set at 60 kt for this advisory.
As the tropical storm moves northward near the Mid-Atlantic coast,
interaction with a strong jet stream is likely to result in a
slower-than-typical weakening rate. The global model guidance
indicates that Isaias is likely to produce widespread
tropical-storm conditions, with hurricane-force wind gusts possible
along the mid-Atlantic coast through this afternoon. As a result,
the gust factor at 12 h has been increased above the standard 20
percent in the Forecast/Advisory (TCMAT4). Isaias is forecast to
weaken more quickly tonight as it moves into eastern Canada and
becomes post-tropical. The post-tropical cyclone is forecast to be
absorbed by a larger extratropical low in 2-3 days, if not sooner.
Isaias is moving north-northeastward or 020/24 kt. The cyclone is
forecast to continue accelerating north-northeastward today as it
is embedded in strong south-southwesterly flow ahead of a deep-layer
trough over the Great Lakes region. After 24 h, the post-tropical
cyclone is expected to decelerate before it is absorbed by the
extratropical low. The updated NHC track forecast is near the
center of the tightly clustered guidance envelope.
In addition to the storm surge and wind threats, Isaias is expected
to produce heavy rainfall along and just west of the I-95 corridor
today, and the Weather Prediction Center has placed a portion of
this area in a high risk for life-threatening flash flooding.
There is also a risk of tornadoes from southeast Virginia to New
Jersey through midday. The risk of tornadoes will spread northward
into southeastern New York this afternoon and across New England by
tonight.
.
|
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
