Area Forecast Discussion Issued by NWS Sterling, VA
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000
FXUS61 KLWX 021020
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
520 AM EST Tue Mar 2 2021
.SYNOPSIS...
High pressure over the Great Lakes will build overhead through
tonight. Low pressure will pass well to the south Wednesday. A
reinforcing cold front will cross the area Wednesday night. Canadian
high pressure will build toward the region Thursday through Saturday,
then move offshore early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
High pressure over the Great Lakes will build overhead today.
Stratocumulus clouds banking up against the Allegheny Front (and
in some instances spilling east of the mountains) should erode
as drier air works in this morning. The wind will start out
gusting 20 to 30 mph out of the northwest this morning, then
diminish after noon as the high pressure center builds overhead.
Temperatures today and tonight are expected to be about 5 to 10
degrees below normal. When factoring in the wind first thing
this morning, it may feel like it`s in the teens and 20s.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Low pressure developing over the northeastern Gulf of Mexico
is forecast to track across northern Florida and southern
Georgia, then into the Atlantic Ocean on Wednesday. This should
keep the northern extent of any precipitation and most clouds
from near the North Carolina/Virginia border southward.
A cold front is forecast to drop southward out of across the
area Wednesday night. A modest uptick in cloud cover and a few
sprinkles or flurries are possible. The wind will then shift to
the north/northwest and increase through Thursday, reinforcing
below normal temperatures.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
Canadian high pressure will build overhead Friday through Friday
night bringing a continuation of dry and chilly conditions for
this time of year. Low pressure in the southern stream of the
jet will pass by to the south Saturday, and as of now it is
expected to remain far enough to the south so that dry and
chilly conditions will persist.
We will have to keep an eye on some northern stream energy that
will pass through our area Saturday night. If the energy is
strong enough, it may cause a few snow showers despite limited
moisture. However, confidence for that to occur is too low to
mention in the forecast at this time.
The high pressure will gradually move offshore Sunday through
Tuesday of next week; a return flow should allow for a moderating
trend in temperatures (especially by Tuesday of next week where
temperatures may be several degrees above climo).
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
VFR expected thru Sat. NW G20-25kt thru 18z, diminishing and
becoming S/SW tonight. W flow 5-10kt Wed, then N/NW 10-15G25kt
thru the end of the week.
&&
.MARINE...
High pressure over the Great Lakes will build overhead through
tonight. Northwesterly wind gusts of 20 to 25 knots are expected
through early afternoon before the high pressure center moves
overhead. A lighter southerly to westerly wind is forecast
tonight into Wednesday, though a period of southerly channeling
likely results in gusts to around 20 knots late this evening
into Wednesday morning. Gusty northerly to northwesterly winds
are forecast to return behind a reinforcing cold front Wednesday
night through much of the later part of the week.
&&
.HYDROLOGY...
The excess runoff from previous rainfall has entered the Potomac
River Basin. Flooding is expected across portions of the Potomac
River Basin through at least tonight before water levels subside
Tuesday and Wednesday. An extended period with several days of dry
weather is likely to persist for the rest of this week into early
next week.
&&
.TIDES/COASTAL FLOODING...
Runoff of rain and snowmelt from a couple days ago is heading
down the Potomac River, and may cause near minor flooding along
the shoreline of Washington DC later this morning. Minor flooding
appears more likely for the tide cycles this evening and again
Wednesday morning.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 3 PM EST this afternoon for
ANZ530>543.
Small Craft Advisory from 10 PM this evening to 6 AM EST
Wednesday for ANZ531>533-537-539>541.
Small Craft Advisory from 10 PM this evening to noon EST
Wednesday for ANZ534-543.
&&
$$
SYNOPSIS...BJL/DHOF
NEAR TERM...DHOF
SHORT TERM...DHOF
LONG TERM...BJL
AVIATION...BJL/DHOF
MARINE...BJL/DHOF
HYDROLOGY...BJL
TIDES/COASTAL FLOODING...DHOF