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202
FXUS61 KLWX 110757
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
357 AM EDT Tue Jun 11 2024

.SYNOPSIS...
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A weak area of low pressure passes off to the southeast while
high pressure returns through Thursday leading to mostly dry
conditions. A cold front tracks through the area on Friday
leading to renewed shower and thunderstorm chances. High
pressure settles over the area this weekend.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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A broad positively-tilted trough currently anchors the Eastern
Seaboard up into the Canadian Maritimes. On the more local
scale, weak ascent accompanying some embedded perturbations in
the flow continue to spark light shower activity. This is
evident on the WSR-88D radar imagery with some weak returns
noted along and east of I-95 in Maryland. While the 06Z RAP
objective analysis depicts 250-500 J/kg of MUCAPE, it is capped
with quite a bit of inhibition (CIN). Thus, do not expect the
ongoing activity to increase in strength as it heads toward the
Chesapeake Bay. Otherwise, the main story will be the mixture of
low to mid-level cloud cover. A mainly overcast sky remains in
control early this morning with current temperatures generally
in the mid 50s to mid 60s. For those near the Alleghenies,
reduced visibilities are evident on multi-channel nighttime
satellite imagery and local observations. These areas of patchy
fog will likely persist until a couple hours after sunrise.

For the rest of the day, the guidance shows weak cyclogenesis
unfolding off the Carolina coast. The swath of showers that
develop with the associated convergence axis mainly stays east
of I-95. As such, have painted an area of isolated showers and
thunderstorms for this region during the afternoon to early
evening hours. Elsewhere, expect the cyclonic flow aloft to keep
a mixed bag of clouds and sun around. This will bring continued
below average temperatures along with reduced humidity levels.
Forecast high temperatures today sit in the mid/upper 70s,
locally falling into the 60s across the higher terrain.

High pressure settles over the Mid-Atlantic back into the
Tennessee Valley tonight. This allows winds to go calm overnight
with some lingering high clouds overhead. Another round of
patchy fog is possible overnight as moisture gets trapped
underneath developing radiation inversions. The most likely area
for such fog development would be from I-81, especially within
river and mountain valleys. Forecast low temperatures stay on
the cool side with widespread 50s expected.
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&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
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The trough axis anchoring the eastern U.S. should more or less
consolidate into a closed low off the New England coastline. The
trailing synoptic flow turns more west-northwesterly in nature
with a gradual increase in mid-level heights. Rebounding heights
coupled with a shift to low-level southwesterly winds will aid
in a warming trend for the middle to latter portions of the work
week. The increase in heights aloft along with high pressure at
the surface should yield a mostly sunny day across the region.
This dry pattern persists through Thursday before the next cold
front impacts the region by Friday. While the mercury will rise
during this transition, dew points stay low enough to prevent
conditions from becoming too humid. By Thursday afternoon,
forecast 850-mb temperatures peak in the 14-17C range. Mixing
this air mass dry adibatically to the surface would yield highs
in the upper 80s to low 90s. Thursday night`s low temperatures
turn to more typical June levels, generally in the mid 60s to
low 70s.
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&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
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A cold front will slide southeast across the region Friday into
Friday night. Warmth and humidity will be increasing ahead of it to
help to fuel any showers and thunderstorms that develop ahead of and
along the cold front. At this time it is too early to tell if
thunderstorms will be typical for June or if they will pack a punch
with damaging winds, hail or tornadoes. Expected high temperatures
will reach the lower to perhaps middle 90s with slightly cooler
temperatures in the western mountains.

High pressure will build in behind the cold front that is expected
to move farther to the south late Friday night into Saturday. The
high will bring lower humidity on a northwest to northerly wind
Saturday. Dry conditions expected with high temperatures about 10
degrees cooler Saturday and highs in the middle 80s.

Dry conditions continue with seasonable temperatures on Sunday with
high pressure shifting its center to the east. By Monday, the high
will be to the east to allow for southeast to southerly winds to
develop and bring back the higher humidity. Although a higher
elevated shower or thunderstorm can`t be ruled out in the
Alleghenies Monday afternoon as highs reach the 90s again, most
areas will be dry.
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&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
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Expect a lengthy period of VFR conditions with surface high
pressure in control of the weather through Thursday night. The
forecast is mainly dry during this period. However, isolated
showers and thunderstorms this afternoon may impact some spots
east of I-95. Depending on how far west these materialize, some
brief restrictions are possible at KDCA, KBWI, and KMTN. May
introduce a VCSH group at these terminals in the next TAF
issuance. Winds through Wednesday stay on the light side given
weak gradients around the ridge of high pressure. Winds shift
from northwesterly to south-southwesterly on Wednesday. This
pattern persists into Thursday with an uptick in gusts on
Thursday, generally up to 10-15 knots.

VFR conditions could briefly become MVFR conditions in any heavy
showers and thunderstorms Friday into Friday evening, particularly
at MRB, IAD, DCA, BWI and MTN. However, confidence at this time is
low that MVFR conditions will occur at these terminals. Winds
southwest 5 to 10 knots shifting to northwest Friday into Friday
night.

VFR conditions return anyway late Friday night through Saturday
night. Winds north becoming northeast 5 to 10 knots late Friday
night into Saturday.
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&&

.MARINE...
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Northerly winds this morning have finally begun to decrease in
strength with gusts topping out between 10 to 15 knots. Expect
isolated showers and thunderstorms this afternoon to early
evening. However, do not expect these to be strong enough to
issue Special Marine Warnings. Winds remain below advisory
levels through mid-week with a shift to southeries the second
half of Wednesday. Southerly channeling effects become more
prominent from Thursday evening into the night, especially over
the wider portions of the Chesapeake Bay.

Any heavy showers or developing thunderstorms that develop Friday
into Friday evening could lead to Special Marine Warnings given the
higher heat and humidity that fuels this activity. Otherwise, no
marine hazards late Friday night through Saturday night. Winds
southwest shifting northwest 10 knots gusts to 15 knots Friday into
Friday night. Winds north becoming northeast 10 knots Saturday and
Saturday night.
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&&

.TIDES/COASTAL FLOODING...
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Sensitive sites like Annapolis and Straits Point will or could see
action stage this morning. Otherwise, tides will behave and remain
below action stage at the other sites today and into the heart of
the weekend.
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&&

.LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.
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&&

$$

SYNOPSIS...BRO
NEAR TERM...BRO
SHORT TERM...BRO
LONG TERM...KLW
AVIATION...BRO/KLW
MARINE...BRO/KLW
TIDES/COASTAL FLOODING...KLW