FXUS61 KLWX 260851

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
351 AM EST Mon Feb 26 2024


Mostly dry conditions continue today with slightly warmer temperatures
as high pressure slides offshore. Temperatures continue to climb
Tuesday along with increased shower chances as a warm front lifts
into the area. More widespread rain chances and gusty winds will
accompany a cold front Wednesday with cooler temperatures Thursday
as high pressure returns. Additional precipitation chances are
expected this weekend.



Despite a weak piece of shortwave energy pivoting through the area
this morning, it`s a mostly dry start to the workweek. Fast
zonal flow looks to continue aloft with increasing south to
southwesterly flow drawing in moisture from the Gulf of
Mexico/Atlantic. This is evident on radar this morning with some
pockets of virga and even a few sprinkles sliding across the
central VA Piedmont into eastern VA. Elsewhere mid and high
level clouds continue to pivot through with clearing evident on
satellite back across northern and central WV.

Weak shortwave energy will exit east this morning with another piece
of weak energy set to follow later this afternoon and into tonight.
With high pressure just off the coast, mostly locations will remain
dry with mostly sunny to partly cloudy skies. A few isolated
showers/sprinkles cannot be ruled out across the Alleghenies and
areas along the immediate Blue Ridge. Confidence is a bit low given
residual dry air in the low levels and the placement of shortwave
energy with most of the guidance trending further south of the
region. Any shower activity that we do see will be fairly light with
only a few one-hundredths of an inch of precip expected.

The bigger story today will be the temperatures. It`s an early tease
to Spring after a chilly weekend. Light south/southwesterly flow at
5 to 15 mph will yield high temps for many in the low to mid 60s
(50s Alleghenies). Lows tonight will fall into the low to mid 40s
with a gradual uptick in cloud cover and areas of patchy fog
(especially around colder waterways) as low level moisture increases
across the region.



A warm front lifts into the Ohio River Valley and Mid-Atlantic
Tuesday bringing increased shower chances and even warmer
temperatures. Overall not expecting a washout Tuesday with on and
off showers passing through the region. 00z hi-res/synoptic guidance
focuses the steadiest rainfall along and west of the Blue Ridge and
north of I-70. Lesser amounts of rain are expected south and east
with shower coverage remaining scattered across the region. Rainfall
amounts up to a quarter of an inch are possible areawide Tuesday
into Tuesday night with locally higher totals west of the Allegheny
Front and north of the PA/MD border where better isentropic lift can
be found.

Outside of the rain chances expect limited sunshine Tuesday with
mostly cloudy to overcast conditions. Even with the cloud cover and
showers high temperatures will push into the low to mid 60S. Winds
will also increase out of the south/southwest with sustained speeds
between 10 to 15 mph and gusts up to 25 mph (especially along
southwestern facing ridges).

Rain chances and winds continue to increase Tuesday night into
Wednesday morning as an additional piece of shortwave energy rides
along the warm front lifting through the region. This will lead to
sustained winds between 10 to 15 mph with gusts of 25 to 35 mph
(especially along the ridges/waters). Lows Tuesday night into
Wednesday morning will fall into the low to mid 50s.

More widespread precipitation arrives Wednesday as a strong cold
front moves into the region. 00z hi-res/deterministic/ensemble
guidance shows good agreement with the front arriving Wednesday
afternoon before quickly racing east Wednesday night into early
Thursday morning. Before the front arrives, a few breaks in the
clouds can be expected in the wake of the warm front exiting
Wednesday morning. This will boost temperatures even further with
highs in the mid to upper 60s and low 70s. On top of this, south to
southwesterly winds at 10 to 15 mph gusting 20 to 30 mph will add a
further boost in temperatures/moisture across the area.

The heaviest precipitation looks arrive late Wednesday afternoon
into Wednesday evening before things quickly shutdown from west to
east Wednesday night into early Thursday morning. Thunderstorm
probabilities are low, but are not zero, for this front, given the
increasing dewpoints and strong forcing. Forecast instability values
are generally 250-400 J/kg with 0-6 km shear values over 80 kts.
Thinking the limiting factors here are the time of day of the
frontal passage and limited solar heating to contribute to diurnal
instability, given the ample cloud cover through Wednesday

Southerly winds will quickly switch to the northwest in the wake of
the front Wednesday evening into Wednesday night. This will lead to
residual precipitation switching from rain showers to snow showers
over the mountains. With precipitation quickly exiting any snow
accumulation will be fairly light and confined to elevations above
2500 feet (i.e western upslope zones of the Allegheny Front and
crest of the Blue Ridge).

Winds will continue to increase Wednesday night into Thursday due in
part to a strong 850 mb low level jet in excess of 50-60 kts+ and
strong pressure rises as high pressure builds in. Gusts of 25 to 35
mph can be expected areawide with gusts of 40 to 50 mph over the
ridges. Wind headlines may be needed to encompass this threat
Wednesday evening and into early Thursday. Lows Wednesday night will
fall into the upper 20s and low to mid 30s. Mountain locations west
of I-81 will crash into the teens and low 20s.



Winds will be on the downward trend Thu as high pressure builds
into the area. Cold Thu night with high pressure overhead. The
high pressure center slides offshore Fri leading to a warming

A shortwave-trough moving across the mid MS and OH River Valleys
will help induce sfc wave development along a coastal front and fuel
moisture return into the area Fri night. Guidance have trended
warmer during the past several runs and away from any mixed
precip in the mountains. The wave moves offshore Saturday with
precip ending. Sfc to mid-level ridging builds in early next
week leading to further warming.



VFR conditions are expected at all terminals through Tuesday morning
with high pressure nearby. Brief LLWS will continue across the
corridor terminals through 12z/7am with light south/southeast
surface flow beneath west/southwest of 25-25 kts at 2-3 kft AGL.
This is in association with a weak piece of shortwave energy
generating pockets of virga and perhaps a sprinkle along and east of
the corridor terminals this morning.

High pressure will reside off the Carolina coast today allowing for
increased southwesterly flow across the region. Winds will remain
light at 5-15 kts with passing mid and high level clouds through the
day. An isolated shower or sprinkle cannot be rules out south and
west of KCHO/KSHD and west of KIAD/KMRB later afternoon into tonight
as another weak piece of shortwave energy kicks through. Most
terminals will remain dry with areas of patchy fog late.

Precipitation chances and winds increase Tuesday as a warm front
lifts in the region. Southwesterly gusts of 15 to 20 kts can be
expected throughout the day with further strengthening Tuesday night
into Wednesday. Some LLWS is also possible during this time. Sub-VFR
conditions can be expected at times Tuesday morning into Tuesday
afternoon as scattered MVFR showers pass through the region. Higher
confidence for sub-VFR conditions exists Tuesday night into
Wednesday with more widespread rain chances entering the area.

A warm front early Wednesday followed by a cold front Wednesday
night will bring multiple rounds of rain showers to the terminals.
MVFR ceilings will be possible with rain activity. There could be a
few breaks of VFR conditions midday Wednesday between batches of
rain or showers with each front. Early Thursday could start as IFR
or MVFR but then become VFR with a gusty wind.  Winds increasing
through the day Wednesday from the south 15 to 25 knots gusts 30
knots Wednesday into Wednesday night.

Winds will be on the downward trend through the day Thu, but
may gust up to 25 kt in the morning before diminishing further
during the afternoon.



An isolated sprinkle is possible before daybreak this morning. Winds
will continue to gust to 25 knots at times, mainly in the open
waters of the lower Chesapeake Bay through mid-morning. Winds
diminish below SCA level this afternoon into early Tuesday before
turning gusty again by Tuesday afternoon. SCAs will likely be needed
Tuesday through Wednesday.

Small Craft Advisories are likely Wednesday through Thursday with
possible gales late Wednesday afternoon into Thursday morning.Gale
watches have been issued to cover this threat given a consistent
signal amongst guidance. This is in association with a series of
fronts that will cross the region. South winds will run 15 to 25 kts
with gusts up to 30 kts Wednesday switching to the northwest

SCA conditions expected Thu morning, dropping below SCA during
the afternoon.


MARINE...Gale Watch from Wednesday afternoon through late Wednesday
     night for ANZ530>543.




NWS LWX Office Area Forecast Discussion