Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 231432
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1032 AM EDT Tue Apr 23 2024

.SYNOPSIS...
High pressure will move to the east today. A cold front will move
through the region Wednesday. A second area of high pressure will
build back in for the end of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
MID-MORNING UPDATE:
Dense cirrus from early this morning has begun to fizzle out.
Some mid to high clouds are expected today, particularly west of
the Blue Ridge, but coverage isn`t expected to increase
significantly until this evening.

The main concern today looks to be elevated fire danger. RHs
this afternoon drop into the 20-30% range with sustained winds
10-15 mph and gusts 20 to 25 mph, which is favorable for drying
fuels and the potential for fire spread. An SPS has been issued
for the entire area from noon through 7PM.

PREVIOUS DISCUSSION FOLLOWS:
High pressure will move to the east today, which will allow for our
winds to turn more out of the south. This will result in a warming
trend, with temperatures climbing into the upper 60s to low 70s
under mostly sunny skies.

A shortwave will track southeastward from the Great Lakes toward the
Northeast/Mid-Atlantic tonight. Precipitation amounts should be
light given the lack of moisture. A few showers will be possible
across the area, especially later tonight into early Wednesday
morning.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A cold front will move through Wednesday morning, causing winds to
turn northwesterly. A gusty northwest wind of 20 to 30 mph will be
possible during Wednesday afternoon. A stray shower or thunderstorm
can`t be ruled out behind the cold front/beneath the upper trough
axis Wednesday afternoon, but most locations should remain dry. High
temperatures Wednesday are expected to be in the upper 60s to near
70.

Cold advection is expected Wednesday night. Temperatures are
forecast to drop into the upper 30s and lower 40s. Additional
opportunities of encountering frost or freeze conditions are
possible Wednesday night. Winds may be a little too high to allow
for frost or freeze conditions.

Dry conditions anticipated on Thursday into Thursday night with high
pressure gaining control. Thursday is also expected to be cooler by
about 10 degrees from Wednesday.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Dry conditions to end the week as surface high pressure slides east
into the western Atlantic on Friday. Weak ridging aloft moves over
the area Saturday. There is a chance for some shower activity,
mainly west of the Blue Ridge on Saturday. However, given the
combination of weak subsidence and downsloping winds (due to nearly
zonal westerly flow above the surface) that mixes drier air from
aloft, any shower chances look to be limited. A warming trend begins
late week as highs go from low to mid 60s Friday to upper 60s to low
70s Saturday (could be higher in some areas due to downsloping
winds).

Sunday into the start of next week is looking dry and very warm as
deep ridging develops across the Southeast and Mid-Atlantic states.
Most models indicate a 580-585 dm ridge aloft over much of the
eastern CONUS, with the Bermuda Highs building over the western
Atlantic. Could be looking at near-record heat Sunday into Monday as
highs reach the low to mid 80s. A weak cold front approaches from
the west on Monday, possibly resulting in isolated to scattered
showers and thunderstorms Monday afternoon. Very mild overnight lows
in the upper 50s to mid 60s Sunday and Monday nights.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
VFR conditions today through Thursday night. Winds light becoming
south around 10 knots today and tonight. Winds southwest becoming
northwest 10 to 15 knots gusts up to 20 knots Wednesday and
Wednesday night. Winds becoming northeast Thursday, then southeast
Thursday night 5 to 10 knots as high pressure builds into the
region.

VFR conditions are likely Friday into next weekend. Limited shower
chances possible Saturday around MRB, otherwise dry conditions are
likely at the other terminals. Southeast winds on Friday become
south for Saturday around 10 knots, with gusts to 20 knots possible
each afternoon.

&&

.MARINE...
Small craft advisories likely this afternoon through Wednesday
morning for the Chesapeake Bay and Potomac River. Small craft
advisories likely again for the main stem of the Chesapeake Bay
Wednesday night. Winds south 10 to 15 knots gusts up to 20 knots
this afternoon through Wednesday morning. Winds northwest becoming
north 10 to 20 knots Wednesday night.

Southerly channeling Friday and especially Saturday could result in
near-SCA conditions over the open waters of the Chesapeake Bay. This
would occur during the afternoon to evening hours each day, when
winds gust around 18-20 knots. Winds decrease overnight into the
morning.

&&

.FIRE WEATHER...
Elevated fire conditions are expected due to dry conditions and
gusty winds. Relative humidity values around 15 to 30 percent are
expected along with sustained southerly winds of 10 to 15 mph and
gusts 20 to 25 mph. This will result in the rapid drying of fine
fuels. Will continue to monitor conditions going into Wednesday,
depending on how much rain actually falls with the frontal passage.

&&

.TIDES/COASTAL FLOODING...
Water levels are expected to steadily increase through tonight as
southerly winds push water up the Chesapeake Bay and lower Potomac
River. Minor coastal flooding is likely at Annapolis during the
early morning high tide cycle Wednesday, and possibly at Straits
Point during that time. Most other locations will reach Action Stage
during the upcoming high tide cycles through Wednesday morning.

Winds turn northwest behind a cold front causing tide levels to
decrease Wednesday night into Thursday.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 2 PM EDT Wednesday for ANZ530>543.

&&

$$

SYNOPSIS...KLW
NEAR TERM...KLW/CAS
SHORT TERM...KLW
LONG TERM...KRR
AVIATION...KLW/KRR
MARINE...KLW/KRR
FIRE WEATHER...CAS/LFR
TIDES/COASTAL FLOODING...KRR


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