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227
FXUS61 KLWX 281849
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
249 PM EDT Tue May 28 2024

.SYNOPSIS...
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A cold front will move over the area Wednesday night, bringing
unsettled conditions tomorrow afternoon and into the early
evening. In the wake of the frontal passage, high pressure will
build in from the northwest and will linger through the weekend.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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An upper level trough and associated weak disturbance will pivot
over the forecast area this afternoon and into the evening. This
increase in moisture aloft can already be noticed in the fair
weather cumulus clouds tracking east across the region. Isolated
showers and thunderstorms are possible east of the Blue Ridge
with Scattered showers and thunderstorms possible in the
northwest portions of the area. The southeastern portions of the
forecast area should remain dry, however, a stray shower cannot
be ruled out this afternoon.

Shower activity should diminish after sunset with skies
clearing up overnight. Low temperatures will fall into the 50s
for most with those at higher elevations dipping into the upper
40s. Metro areas will be slightly warmer tonight, with low
temperatures staying in the low 60s.
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&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
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An upper level trough will pivot overhead Wednesday as a reinforcing
cold front moves through the area Wednesday evening. Shortwave
energy moving overhead tomorrow afternoon will bring increased
coverage for showers and thunderstorms. QPF totals generally
remain below 0.25" so flooding threat remains low. The airmass
will be relatively stable with limited instability, so the
threat for severe weather remains low.

Shower and thunderstorm chances will decrease Wednesday night
with the loss of daytime heating. Dry conditions are expected
on Thursday as dry air moves in aloft. Winds remain out of the
northwest, gusting up to 15 knots in the wake of a frontal
passage.

There will be a temperature gradient across the forecast area on
Wednesday with high temperatures ranging from the low 60s in the
Alleghenies to nearing 80 along I-95 and in the southern
portions of the area. Overnight low temperatures will be in the
upper 40s at higher elevations with the rest of the area staying
in the 50s. In the wake of the frontal passage Wednesday night,
high temperatures on Thursday will be a few degrees cooler when
compared to the previous day. Highs will be in the low 60s for
those at higher elevations with the rest of the area in the mid
70s. Low temperatures on Thursday night dip into the low 40s
with those further east staying in the mid to low 50s.
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&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
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The trough axis will be to the east Friday, so there should be less
cloud cover overall. Northwest flow will support another day with
below normal temperatures and low humidity. The surface high will
move nearly overhead by Saturday morning, so there should be
favorable radiational cooling Friday night. Outlying areas should
easily fall into the 40s again, while some of the deeper valleys
could fall into the 30s. A narrow ridge will build aloft Saturday
while the surface high continues to drift to the southeast.
Temperatures will warm several degrees to around or above normal.

The ridge axis will push to the east Sunday and a more zonal flow
will develop across the eastern half of the country. Timing of
individual waves in this regime is uncertain, rather there will just
be a gradual return to more unsettled weather as we remain on the
warm side of low pressure systems tracking well to the north.
Ensemble precipitation probabilities and experimental convective
machine learning guidance suggest potential for a more active day on
Tuesday. Temperatures will continue to run above normal through
early next week while humid air gradually makes a return.
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&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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VFR conditions are expected for the rest of today and overnight
as westerly winds diminish this evening. A stray shower or
thunderstorm cannot be ruled out this afternoon, but confidence
on where those will initiate was too low to include in TAFs.
Either way, most locations are expected to remain dry with any
precipitation being isolated and shallow. Westerly winds will
diminish this afternoon before shifting to northwesterly
tonight. Fair weather cumulus clouds over the terminals this
afternoon will clear to mostly clear skies overnight.

Winds remain out of the northwest Wednesday blowing 5-10 knots.
Shower and thunderstorm chances increase Wednesday afternoon, so
introduced -SHRA to IAD, DCA, and BWI. Though winds remain out
of the northwest Thursday, winds gust up to 15 knots in the wake
of a cold front passage. VFR conditions are expected both days
with the precipitation chance decreasing for Thursday.

No significant weather expected Friday and Saturday with high
pressure. Low chance of a thunderstorm Sunday depending on the
timing of the next disturbance.
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&&

.MARINE...
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Westerly winds gusting up to 20 knots are expected until 7PM
this evening with a Small Craft Advisory in effect for the upper
portions of the Chesapeake Bay and Upper Tidal Potomac. Winds
decrease to below SCA criteria tonight and shift to
northwesterly.

As a cold front moves over the area, showers and thunderstorms
may impact the waters on Wednesday. SMWs may be needed as any
storms move over the waters. In the wake of the frontal passage,
northwesterly winds pick up to SCA criteria Wednesday night.
Winds are expected to remain below SCA criteria on Thursday.

Lingering marginal SCA conditions are possible Friday morning, but
overall winds will be lessening through Saturday as high pressure
builds into the area. Winds will become southerly by Sunday but may
not increase appreciably.

&

.TIDES/COASTAL FLOODING...
Winds will remain out of the west today before shifting to
northwesterly tonight through Thursday. This will lead to
decreasing tidal anomalies with no coastal flooding anticipated
for the next few days.
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&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 7 PM EDT this evening for
     ANZ530>532-535-536-538>540.

&&

$$

SYNOPSIS...AVS
NEAR TERM...AVS
SHORT TERM...AVS
LONG TERM...ADS
AVIATION...ADS/AVS
MARINE...ADS/AVS
TIDES/COASTAL FLOODING...AVS