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833
FXUS61 KLWX 221912
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
312 PM EDT Wed May 22 2024

.SYNOPSIS...
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Surface high pressure will continue to shift offshore as a cold
front approaches the area from the west through tonight. The cold
front will move over the Mid-Atlantic throughout the day on Thursday
before lifting northward as a warm front Friday afternoon.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 2:15PM, storms are beginning to initiate along and west
of the Blue Ridge and move eastward across the forecast area.
While more favorable conditions for strong to severe
thunderstorm development lie to the west of the I-95 corridor,
SBCAPE values of 2000-3000 J/kg and steep lapse rates are
expected areawide. Bulk shear will be lacking along the I-95
corridor with higher values of 30-40 knots expected in the
western half of the area.

Showers and thunderstorms will continue moving eastward this
evening with damaging wind gusts and large hail as the main
hazards expected. With convection initiating earlier, storms
will move out of the area earlier with light rain showers
persisting through the overnight. PWATs 1.25-1.75 inch are
expected providing ample moisture for heavy rain. There is
enough flow to keep the flooding risk low, but locally heavy
rain could result in an excessive rainfall risk.

Temperatures will rise into the mid to upper 80s this afternoon
with higher elevations staying in the upper 70s. Overnight lows
dip into the 60s with metro areas staying in the low 70s.
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&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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An approaching cold front from the west will move over the Mid-
Atlantic Thursday afternoon before lifting northward as a warm
front Friday afternoon. This nearby boundary will provide
stronger forcing for daily shower and thunderstorm chances. The
threat for convection is higher on Thursday compared to Friday
with the cold front moving overhead. Cloud cover could inhibit
convection development but SBCAPE values 1500-2500 J/kg, bulk
shear around 35 knots, and lapse rates 6-7C/km will allow for at
least a conditional risk for strong to severe thunderstorms.

Showers and perhaps a thunderstorm continue overnight as the
front remains nearby. As the front lifts north of the area on
Friday, precipitation chances decrease Friday morning. Slight
chance to chance PoPs continue throughout the day with plenty of
moisture aloft.

Shortwave energy moving aloft will continue a slight chance for
showers and thunderstorms. The threat will be mostly confined to
the southern portions of the forecast area.

Temperatures will be in the 80s for most with higher elevations
staying in the mid to upper 70s. Overnight low temperatures will
be upper 50s to mid 60s.
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&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
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Unsettled conditions will continue through the holiday
weekend and into early next week. Strong to severe thunderstorms
will be possible Saturday through Monday, with the best chances on
the bookends of the period. A shortwave trough on Saturday will move
through the area with increasing instability during the afternoon
and evening hours. Highs will top out in the low 80s on Saturday. By
Sunday, thunderstorm chances remain but forcing may be a bit weaker
compared to Saturday, so overall coverage and intensity of the
storms may be a bit lower comparatively.

By Monday, a strong cold front will approach the area as a result of
a deep low pressure system situated near the Great Lakes region.
Strong to severe thunderstorms will certainly be possible Monday
afternoon and evening. Main hazards for this system will be damaging
winds and large hail. Afternoon highs will climb into the upper 70s
to low 80s across much of the area. Cooler and less convective
conditions arrive behind the front on Tuesday with highs in the 70s
and overnight lows dropping down into the mid to upper 50s.
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&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
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VFR conditions are expected at all terminals with the exception
of reduced flight conditions during showers and thunderstorms
this afternoon. Greatest chances for thunderstorms still remains
in the western terminals (MRB, CHO, and IAD) where more favorable
conditions are. Thunderstorms move out of the area this evening
around 00Z-02Z. For the 18Z TAFS, kept a wider range for timing
of thunderstorms due to model uncertainty. Storms are firing up
along and west of the Blue Ridge, so am expected storms to
impact the metro terminals in the next few hours. Overall,
winds remain light and blowing out of the southwest this
afternoon at around 5 knots. Winds shift to westerly by Thursday
morning and will remain out of the west through Friday
afternoon.

Diurnally driven showers and thunderstorms are possible
Thursday and Friday, bringing chances for flight restrictions at
all terminals.

Sub-VFR conditions will be possible Saturday and Sunday with any
showers and thunderstorms that cross the terminals, especially in
the afternoon and evening. Winds will be fairly light out of mainly
the south.
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&&

.MARINE...
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Southerly winds over the waters gust 15-20 knots this afternoon
and through overnight before diminishing before sunrise Thursday
morning. A Small Craft Advisory is currently in effect until 2AM
Thursday morning for winds blowing 10-15 knots and gusts up to
20 knots expected.  Winds shift to southwesterly Thursday
morning before shifting to westerly in the afternoon.

Winds remain below SCA criteria through Friday. Daily shower and
thunderstorm chances may bring hazardous conditions to the
waters with some possibly requiring SMWs.

Sub-SCA winds are expected for the weekend aside from any showers
and thunderstorms that cross the waters. Special Marine Warnings may
be needed both afternoons and evenings.
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&&

.TIDES/COASTAL FLOODING...
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Minor coastal flooding is possible at DC Waterfront, Annapolis,
and Havre De Grace with the high tide cycle Thursday morning.
After high tide Thursday morning, winds shift from southerly to
westerly allowing tidal anomalies to begin decreasing.
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&&

.LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 2 AM EDT Thursday for ANZ530>534-
     537>541-543.
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&&

$$

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