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431
FXUS61 KLWX 310033
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
833 PM EDT Thu May 30 2024

.SYNOPSIS...
High pressure will gradually build toward the area through
Friday night, before progressing offshore on Saturday. High
pressure will remain offshore through early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
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Very dry air is being observed at all levels at this hour, as
evident in current water vapor imagery and in the 00z IAD RAOB.
As a result, clouds have quickly subsided with the onset of
sunset this evening. Winds have also subsided this evening over
the past hour.

A cool night is anticipated with lows around 50 east of the
Blue Ridge Mountains and 40s west. A few spots at the higher
elevations could drop in the low to mid 30s. Have expanded frost
advisories up through Garrett county, MD tonight given expected
cooler temperatures and more moisture laying around from recent
rains.
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&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure will settle overhead Fri with light winds and
plenty of sunshine. Temps will continue to run below normal and
new Frost Advisories may be needed again for those same areas as
tonight. High pressure shifts offshore Saturday with southerly
winds returning boosting daytime temperatures. There will be
plenty of high clouds Saturday resulting in partly sunny skies.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Upper level ridging will begin to buckle while surface high pressure
slides offshore Sunday into the early part of next week. This will
give way to a zonal flow pattern aloft allowing a series of
disturbances to pivot east from the Upper Midwest and Great Lakes
region. With high pressure offshore, low level moisture will be
allowed to return on south to southwesterly flow. This will
also boost temperatures back above average across the region
leading to an increasingly unstable airmass heading into the
early and middle part of the new workweek. With that said, daily
chances for showers and thunderstorms exist each afternoon
through Wednesday. 06/12z synoptic/ensemble guidance have
trended slower with the moisture and disturbances reaching the
forecast area, so have favored lower precipitation chances east
of the Blue Ridge Sunday and Monday compared to areas west where
orographic lifting can aid in convective development. The
threat for showers and thunderstorms becomes a bit more
widespread Tuesday and Wednesday afternoons given the uptick in
moisture as well as instability from the increased temperatures
across the region. More organized convection looks to hold off
beyond the extended period as a cold front enters the region
from the Ohio River Valley.

Rainfall amounts are expected to be light at this point and no
severe weather is anticipated at this point. Neither SPC nor WPC
have highlighted any threats over the region for the period at this
time. Even with that said, CSU Learning Machine Probabilities and
CIPS analogues continue to point toward stronger storms during the
Wednesday and Thursday timeframe. This is in association with a cold
front that will slowly progress eastward by the latter half of next
week. We will continue to monitor this threat over the next several
days.

Temperatures will creep back toward normal Sunday and Monday before
heading back above normal midweek. Highs will warm back into the low
to mid 80s Sunday and Monday with upper 80s midweek. 850 mb
temperatures running +12 to +16 degrees C. Overnight lows will
return to the mid to upper 50s and low 60s.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
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VFR conditions are expected at all terminals through Saturday. Winds
will remain out of the north Friday before turning southerly
Saturday. Speeds will remain light at 5 to 15 kts.

VFR conditions are expected Sunday with high pressure just offshore.
A slight chance for a few thunderstorms is possible mainly at
terminals along and west of a line from KMRB down to KCHO. Some
restrictions are possible in and around any thunderstorm activity
that may form. Higher chances for more widespread restrictions from
shower and thunderstorm activity are possible during the afternoon
and evening hours Monday through Wednesday as multiple pieces of
shortwave energy push through. Highest chances for thunderstorms
will be at terminals west of a line from KHGR/KMRB/KIAD south toward
KCHO and KLYH.
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&&

.MARINE...
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Winds briefly subside this evening before picking back up early
Friday morning, especially over the open waters of the bay and
lower tidal Potomac. Sub-SCA level winds are expected late
Friday afternoon through Saturday as high pressure settles
overhead. Winds will become light and variable before switching
to the south Saturday afternoon.

Sub-SCA level winds are expected Sunday into Monday. South to
southeasterly winds return Sunday as high pressure pushes off the
southeast U.S coast. An isolated shower or thunderstorm cannot be
ruled out due to the bay breeze Sunday afternoon/evening. Better
chances for showers and thunderstorms exists Monday through
Wednesday as multiple disturbances pass through. Cannot completely
rule out the need for a Special Marine Warning for any strong storms
that cross the waters during that period.
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&&

.LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None.
MD...Frost Advisory from 2 AM to 8 AM EDT Friday for MDZ001.
VA...Frost Advisory from 2 AM to 8 AM EDT Friday for VAZ503.
WV...Frost Advisory from 2 AM to 8 AM EDT Friday for WVZ501-505.
MARINE...Small Craft Advisory from 2 AM to 11 AM EDT Friday for
     ANZ530>534-537>543.
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&&

$$

SYNOPSIS...EST
NEAR TERM...LFR/CJL
SHORT TERM...LFR
LONG TERM...EST
AVIATION...LFR/CJL/EST
MARINE...LFR/CJL/EST