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000
FXUS61 KLWX 251848
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
248 PM EDT Thu Apr 25 2024

.SYNOPSIS...
A weak area of low pressure will continue to push further offshore
today while high pressure wedges it`s way south along the eastern
Appalachians Friday into Saturday. Cooler temperatures will prevail
as a result along with increased cloud cover. A warm front lifts
through the area this weekend bringing a significant warm up Sunday
and Monday. The next chance for widespread precipitation arrives
with a cold front Tuesday into Wednesday next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A weak piece of shortwave energy aloft will continue to push further
off the lower Delmarva coast this afternoon. With shortwave energy
aloft and a lee standing wave in place increased cloudiness (i.e low
and mid level stratus) persists across a large portion of the
forecast region.

Excess cloud cover will remain prevalent through this evening as
onshore east to northeast flow increases with high pressure wedging
south from the eastern Great Lakes region. This will hold
temperatures in the mid to upper 50s and low 60s throughout the day
with upper 40s and low 50s over the mountains. Cloud cover will
linger tonight although some clearing is likely especially along the
PA/MD border and back across central/northeast MD. These areas do
have the potential to see a little frost with overnight lows in the
mid to upper 30s. Confidence is moderate given the extent of the
cloud cover and clearing along the periphery of the wedge. For that
reason, have went ahead with a Frost Advisory for Cecil, Harford,
Carroll, and northern Baltimore counties in Maryland where better
clearing looks to take place. Temperatures in these locations will
run 34 to 37 degrees. Elsewhere lows are expected to remain in the
upper 30s and low 40s especially where low and mid level (stratus)
clouds look to hang on. Some patchy drizzle is even possible by
daybreak Friday morning along the crest of the Blue Ridge and
eastern slopes of the Alleghenies as moisture increases on southeast
flow.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure over the New England states will remain wedged along
the eastern slopes of Alleghenies and Blue Ridge heading into the
start of the weekend. This will result in continued cloudiness at
times along with near normal to slightly below normal temperatures.
Highs Friday will push back into the low to mid 60s with 50s over
the mountains. Overnight lows Friday will fall back into the low to
mid 40s.

By Saturday, surface high pressure will continue to nudge south and
east off the southern New England coast into the western Atlantic
for the start of the weekend. Meanwhile, at the surface a warm front
will lift north along the western periphery of the surface high and
push toward the eastern Great Lakes Saturday into Sunday. This front
may lend to a few showers mainly along and west of the Blue Ridge
although moisture should remain limited with upper level ridging
quickly building in from the southeastern U.S. High temperatures
Saturday will range from the upper 50s and low 60s north of I-66/US-
50 with mid to upper 60s further south. This spread is due largely
in part to the placement of the warm front, widespread cloud cover,
and rain chances across portions of the region.

The wedge finally breaks Saturday night and into the day Sunday as
strong upper level ridging builds in from south and surface high
pressure sits off the NC coast. This will send an ample supply of
warm air advection over the region yielding a Summertime feel for
the last weekend of April 2024. Lows Saturday night will fall in the
upper 40s and low to mid 50s. Conditions will remain dry with skies
gradually clearing daybreak Sunday morning.


&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
A strong upper-level ridge will build over the region Sunday before
reaching its peak intensity on Monday. This will lead to well above
average temperatures, with some areas potentially pushing 90 on
Monday along the I-95 corridor.

A weakening upper trough will lift to our northwest on Tuesday as it
ejects out of the central CONUS into the Great Lakes region. A weak
piece of shortwave energy breaks off as this happens and slides
across our region. An accompanying "cold front" will push through
and perhaps pop off some thunderstorms during the afternoon/evening
hours. There should be enough instability and some decent wind shear
aloft to produce some strong to severe thunderstorms as well. The
amount of instability is still a bit in question however, as this
system doesn`t have a strong link to the Gulf of Mexico moisture
source, thus keeping dew points down into the upper 50s to low 60s.
Given that this is day 6 at this point, lots of time for things to
change, so stay tuned to the latest forecast each day.

Showers and a few storms possible again on Wednesday with an even
weaker shortwave traversing the region. Not much relief from the
heat from the previous front, as highs remain in the mid 80s.


&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
Predominantly VFR conditions are expected through the valid TAF
period. A brief period of patchy drizzle/fog could effect KCHO/KSHD
late tonight into early Friday morning reducing cigs/vsbys into the
MVFR to IFR categories. Winds will remain light out of the east and
northeast running 5-10 kts through this evening before becoming
light and variable overnight. Highest gusts up to 20 kts can be
found close to the waters and up along the higher ridges/high
valleys.

Overall cigs will remain BKN-OVC across the terminals through Friday
with high pressure over New England wedging south east of
Alleghenies and Blue Ridge. Highest cloud coverage will be confined
to terminals south and west of corridor with more clearing within
the corridor and north/east late tonight into Friday. VFR conditions
will prevail during this time although cloud cover will fill back in
at all TAF terminals late Friday evening and into the day Saturday
as a warm front lifts through the region. This front will provide a
few spotty low end VFR to high end MVFR showers to terminals west of
the Blue Ridge. It will also bring a change and increase in the wind
from the southeast Friday to the south Saturday ushering in warmer
conditions. Gusts of 20 to 25 kts can be expected Saturday as the
front passes through.

Southerly winds will remain elevated Sunday and Monday although gust
will remain below 20 kts. VFR conditions are expected with a strong
upper level ridge overhead.

A potent upper-level ridge will keep things quiet through Monday
with VFR conditions expected. A cold front will approach the area
Tuesday bringing the potential for sub-VFR showers and
thunderstorms.


&&

.MARINE...
Northeast to easterly winds continue to sit below sub-SCA
levels this afternoon although some channeling has been noted
across the central Chesapeake Bay. Remaining Small Craft
Advisories will expire around 4pm. Will continue to monitor for
any channeling over the open waters of the bay/tidal Potomac
late tonight into Friday. Sub- SCA level southeasterly winds are
expected Friday although channeling remains possible late in
the afternoon and evening hours.

Winds could flirt with SCA criteria for a few hours on both Saturday
and Sunday. A warm front will lift across the waters Saturday
changing the winds toward more of a southerly direction. With
surface high pressure off the Carolina coast expected, southerly
winds Saturday to change to more of a south/southwesterly direction
Sunday. Gusts of 15-20kts are expected Saturday with 20-25 kts gusts
possible Sunday due to southerly channeling.

Surface high pressure offshore will bring a southerly flow to the
region, which could channel up the Chesapeake Bay at times. This
could necessitate SCAs through Monday.

&&

.TIDES/COASTAL FLOODING...
Coastal Flood Watches are in effect for Annapolis and Straits Points
as moderate coastal flooding is possible during the high tide cycle
late tonight into early Friday morning. Other spots could reach
minor flood stage, which would require additional Coastal Flood
Advisories.This is due part to increased northeast to easterly flow
eventually switching to the south/southeast this weekend. Additional
periods of coastal flooding are likely over the weekend as southerly
winds persist, and many locations approach or reach minor flood
stage.


&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Frost Advisory from 2 AM to 8 AM EDT Friday for MDZ005-006-008-
     507-508.
     Coastal Flood Watch from 2 AM EDT Friday through Friday
     morning for MDZ014.
     Coastal Flood Watch from midnight EDT tonight through Friday
     morning for MDZ017.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 5 PM EDT this afternoon for
     ANZ531>534.

&&

$$

SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...EST
LONG TERM...CJL
AVIATION...CJL/EST
MARINE...CJL/EST
TIDES/COASTAL FLOODING...EST/KRR