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fxus61 klwx 220853 

Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
353 am EST Wed Feb 22 2017

Synopsis...a weak disturbance will cross the area today.
A cold front will pass through the area on Saturday. High
pressure builds over the area during the early part of next


Near term /through tonight/...high pressure is stretched along the
mid-Atlantic and New England coastlines this morning. A closed
upper level low is located over the Gulf Coast states while a
weak shortwave trough moves across the mid-Atlantic region. Most
of the moisture is located south and west of the region however
enough is present to produce showers across the Virginia Highlands,
Shenandoah Valley and central foothills this morning. Light
showers will likely stretch eastward into northern Virginia and the
southern suburbs of District of Columbia this morning however most of the showers
will stay confined to the south... across central Virginia. Mid-high
level clouds will persist today however warm air advection will
lead to temps rising into the mid 60s. Breaks in the clouds are
possible this afternoon mainly north of I-66/Maryland Route 50.

Moisture will continue to advect into the mid-Atlantic region from
the southern stream system through tonight. Low clouds and fog are
expected by Thursday morning as dewpts remain elevated. Temps will
drop into the u40s/l50s tonight.


Short term /Thursday through Friday night/...the southern stream system
will persist off the southeast coast Thursday and Thursday night. Due
to the southwesterly flow aloft...moisture advection and above
normal temperatures will persist. A cold front will approach the
mid-Atlantic region Thursday and showers are possible Thursday
afternoon mainly west of the metros. Showers may move east
across the metros Thursday evening however the cold front will
stay north of the region and amts will be light. A mix of sun
and clouds will allow temperatures to reach the mid 70s and 60s
near the waters.

Showers move east and dissipate across the region by Friday morning.
Dry conditions expected Friday. Another warm day expected with
temperatures reaching the mid to upper 70s. A strong system will
approach the mid-Atlantic region Friday night and showers are
possible as southerly flow increases.


Long term /Saturday through Tuesday/...cdfnt will move through
the fcst area Sat afternoon with showers and possible T-storms.
Simulated satellite imagery from both European model (ecmwf) and GFS shows strong
convection over Ohio Fri night weakening as it approaches the
Appalachians Sat morning with a narrow frontal rain band
developing east of the Blue Ridge Sat afternoon. The simulated
imagery shows convection deep enough to produce lightning north
of I-70 with shallow convection south of there. 850 mb winds peak
between 35-45kt and cape values rise between 100-350 j/kg. A few
severe T-storms may develop along the PA border. Cdfnt clears
the Chesapeake Bay by 00z sun.

High pressure then builds over the area Sunday night and early
Mon. Developing waa pattern on Monday will result in increasing
chances of precip Mon afternoon. Warm and unsettled conditions
will then prevail through Wed before a cdfnt clears the area by
next Thu. Guidance also suggest another chance at reaching 80f
on Wed with h85 temps as high as 17.5c and 1000-850 mb
thicknesses of near 1400 meters under a strong SW flow.


Aviation /08z Wednesday through Sunday/...VFR conditions expected
today as light southerly winds persist. Low clouds and/or fog
are expected Thursday morning. MVFR/IFR restrictions are
expected at all terminals. Clouds will dissipate by mid morning
Thursday and VFR conditions are expected. S winds continue
through Friday night.

Cdfnt to move through terminals around 18z Sat with showers and
possible T-storms with gusty winds.


Marine...high pressure will remain off the coast through Thursday night.
A southerly flow is expected during this time...but wind speeds
should remain below Small Craft Advisory criteria. Dry conditions expected for Friday
before a cold front moves across the mid-Atlantic on Saturday.

Strong cold front will move through the waters Sat afternoon
with showers and possible T-storms some of which could produce
strong winds and require smws particularly across northern
portions of the waters.



Warmest februaries

Dca BWI iad
1. 46.9 (1976) 44.0 (1976) 42.1 (1990)
2. 45.2 (1990) 43.9 (1949) 41.1 (1976)
3. 44.7 (1997) 43.3 (1890) 41.0 (1998)
4. 44.3 (2012) 42.7 (1932) 40.9 (2012)
5. 43.9 (1949) 42.6 (1909) 40.5 (1997)

Feb 2017 (through the 20th)

Dca: 44.9 bwi: 41.5 iad: 41.9

Warmest Winters (dec 1-Feb 28)

Dca BWI iad
1. 44.7 (1931-32) 45.3 (1931-32) 40.0 (2011-12)
2. 44.3 (1889-90) 44.4 (1889-90) 39.7 (2001-02)
3. 43.3 (2011-12) 42.4 (1948-49) 39.4 (1997-98)
4. 43.2 (2001-02) 41.9 (1949-50) 39.0 (2015-16)
5. 42.8 (1949-50) 41.3 (1879-80) 38.3 (1990-91)

Winter 2016-17 (through Feb 20)

Dca: 42.9 bwi: 39.6 iad: 39.8

Temperature records for the Washington District of Columbia area have been kept at
Ronald Reagan National Airport (dca) since 1941. Additional
temperature records for the Washington District of Columbia area date back to 1872.

Temperature records for the Baltimore Maryland area have been kept at
Baltimore-Washington international thurgood Marshall Airport (bwi)
since 1950. Additional temperature records for the Baltimore Maryland
area date back to 1872.

Temperature records in the Dulles Virginia area have been kept at
Washington Dulles International Airport (iad) since 1962.

All records are considered preliminary until reviewed by the
National center for environmental information (ncei).


Lwx watches/warnings/advisories...
District of Columbia...none.


near term...hsk

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