717
FXUS61 KLWX 111434
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1034 AM EDT Tue Jun 11 2024

.SYNOPSIS...
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.

&&

.NEAR TERM /THROUGH TONIGHT/...
The mid-level stratus deck that had been present earlier has
since dissipated. In its place however, a growing cumulus field
is developing and overspreading much of the region. See
previous discussion for more forecast details, as nothing was
really changed during the morning hours.

PREVIOUS DISCUSSION: 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.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
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 adiabatically 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.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
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.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
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.

&&

.MARINE...
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 southerlies 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.

&&

.TIDES/COASTAL FLOODING...
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.

&&

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

&&

$$

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