000
FXUS61 KLWX 260122 CCA
AFDLWX

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

.SYNOPSIS...
High pressure wedges its way south along the eastern
Appalachians tonight 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/...
Cloud cover will remain prevalent tonight as onshore easterly
flow increases with high pressure wedging south from the eastern
Great Lakes region. However, 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 NIGHT 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 /01Z FRIDAY THROUGH TUESDAY/...
Predominantly VFR conditions are expected through the valid TAF
period. A brief period of patchy drizzle/fog could effect
KCHO/KMRB 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.

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
along and 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...
As of 2100 LT, east to southeast winds are periodically gusting 15
to 18 knots along the Chesapeake Bay and portions of the Tidal
Potomac. Occasional gusts to near 20 knots are possible through this
evening with winds diminishing in the next two hours. 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 Advisories are in effect for Annapolis, Straits
Points, and DC SW Waterfront for the Friday AM high tide. Near
moderate coastal flooding is possible near Annapolis and Straits
Point. Other spots could reach minor flood stage, which would
require additional Coastal Flood Advisories. This is due in 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...Coastal Flood Advisory from 8 AM to 1 PM EDT Friday for DCZ001.
MD...Frost Advisory from 2 AM to 8 AM EDT Friday for MDZ005-006-008-
     507-508.
     Coastal Flood Advisory from 2 AM to noon EDT Friday for MDZ014.
     Coastal Flood Advisory from midnight tonight to 7 AM EDT
     Friday for MDZ017.
VA...None.
WV...None.
MARINE...None.

&&

$$

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