FXUS61 KAKQ 201206

National Weather Service Wakefield VA
706 AM EST Wed Feb 20 2019

Low pressure will track northeast from the Gulf of Mexico
today. A frontal boundary then stalls over the Southeast and Mid
Atlantic states through Friday. Another low pressure system arrives
by Saturday.


As of 705 AM Wednesday...

GOES wv imagery continues to show a deep trough over the
Intermountain West and High Plains, with a ridge over the
subtropical wrn Atlantic. A potent trough is lifting NE through
the central Conus, with 1037mb surface high pressure is
centered over Srn New England, and an inverted trough over the
Tennessee Valley. Pcpn has slowly arrived early this morning,
and began as a RA/IP mix, before changing to SN. However, the
intensity has been light and temperatures have slowly dropped
to 32F for most locations from the Piedmont to the MD Ern
Shore, and hence the threat for FZRA is diminishing.

850mb WAA strengthens this morning. Therefore, 850-700mb
thickness values will rise very quickly while 1000-850mb
thickness values will be slower to increase as surface high
pressure remains in vicinity of srn New England. Therefore,
expect snow to quickly transition to sleet, with freezing rain
still possible over the NW Piedmont. All rain should push into
s-central VA after 7am, and then NW of the I-85/US 360 corridor
after 10am. Warm air aloft will continue to deepen during the
aftn, while the cool surface layer will slowly shallow. Most
areas will rise above 32F by mid-late aftn, with the exception
of the far NW where some pockets of freezing rain could
continue. Snow accum is forecast to range from a T-0.1" from the
SW Piedmont to the VA Ern Shore, with 0.5-1.0" from the central
Piedmont toward the RIC metro and most of the MD Ern Shore, and
1-3" for the NW Piedmont, n-central VA, and Dorchester MD. Ice
accum is forecast to range from a T to a few hundredths of an
inch for the I-95 corridor and 0.05-0.10" over the Piedmont.
Winter Weather Advisories remain for the Piedmont to the RIC
metro to the Nrn Neck and MD Ern Shore. Forecast highs today
range from the low 30s NW to the upper 30s/low 40s central, and
low 50s far SE.


As of 405 AM EST Wednesday...

Mostly rain by tonight (albeit a cold rain NW) with
temperatures remaining rather steady through the night. A cold
front aloft slowly pushes through the area Thursday with the
highest rain chances shifting SE. Temperatures will be
challenging Thursday and will largely be dictated by whether or
not any clearing can occur by aftn. Temperatures aloft will be
quite warm (6-10F) at 850mb, but the low-level cool airmass my
not completely scour out if clouds hold strong. For now,
forecast highs are mainly in the 50s. Total liquid QPF for the
event ranges from 0.75" S to 1.25" N.

A weak boundary will linger across the southern tier of the CWA
into Friday. Could see some lingering showers/light rain across
the SE with shallow overrunning moisture on Friday. However,
should just portend to more clouds than sun and a short-lived
lull in precipitation Friday. Slightly cooler with highs mainly
in the upper 40s to low 50s.


As of 340 PM Tuesday...

High pressure slowly moves from NY to New England Fri as a
CAD/wedge pattern remains in place over the CWA. An area of
steady light-moderate rain will quickly overspread the entire
region (from SW to NE) late Fri evening through Sat AM as a
potent upper shortwave (along w/ sfc low pressure) moves from
the Rockies to the Plains/Midwest. Rain continues throughout the
region during the day on Sat. A warm front lifts N toward the
region late Sat (and crosses the region Sat night) in response
to a deepening area of sfc low pressure tracking from the Plains
to the Midwest. Temperatures remain in the 40s in most areas on
Sat as the rain falls. The steady rain departs to the N/NE Sat
night as the warm front crosses the region. Temperatures will
slowly rise Sat night (forecast temps at 12z Sun range from the
upper 40s NW-upper 50s SE) as winds veer to the S then SSW
behind the front. Shower chances continue on Sun before the
trailing cold front crosses the region during the aftn as the
aforementioned sfc low tracks into SE Canada. Not much in the
way of QPF w/ the cold FROPA on Sun. Expect it to be a warm day
throughout the region on Sun as temperatures rise into the low-
mid 70s in most areas (w/ 60s on the ern Shore).

Drier (but not that cold) Mon/Mon night as sfc high pressure briefly
settles into the region. Our next chance of rain is late Tue-Wed, as
low pressure approaches from the west. Highs on Mon will be in the
upper 50s-low 60s in most areas (except for mid 50s on the Ern
Shore). Lows mainly in the 30s Mon night w/ highs rising into the
upper 40s N-mid 50s in SE VA/NE NC on Tue.


As of 700 AM EST Wednesday...

High pressure is centered over Srn New England as of 12z, with
low pressure over the Tennessee Valley. Light FZRA is occurring
at RIC and should change to RA by 14z. SN should begin at SBY by
around 14z, transition to SN/PL by midday and then RA by aftn.
PHF/ORF/ECG should generally be rain-free for the next few
hours, before rain develops later this morning into the aftn.
Vsby is expected to drop to 2sm or less in SN at SBY and
generally be 2-5sm at RIC, with 3-5sm at PHF/ORF/ECG once RA
(and BR) develops later this morning. RIC should mainly have an
IFR cig through the TAF period, with IFR cigs developing at SBY
later this morning, closer to midday at PHF, and after 18z at
ORF/ECG. IFR cigs will persist into tonight along with
occasional RA/DZ.

The chc of rain gradually ends from NW-SE Thursday with
conditions slowly improving. High pressure builds N of the
region Thursday night into Friday. However, moisture will
continue to spread over the region with clouds and a minimal chc
of light rain continuing. Low pressure, and more rain and
flight restrictions are expected Friday night into Saturday. A
cold front crosses the region Saturday.


As of 300 AM EST Wednesday...

Sfc hi pres sits from near the mid-Atlantic coast nwd to far SE
Canada attm...w/ complex lo pres taking shape invof lower MS
Valley. Primary lo pres expected to track NNE to the Great Lakes
today...pulling a frontal boundary nwd from the SE states. A
weak secondary area of lo pres will develop along that boundary
over the coastal Carolinas this afternoon...then track through
the tidewater of SE and E VA late this afternoon/evening before
a cold front from the WNW enters the local waters during Thu.

ENE winds starting out from 5-15 kt...are slow to increase this
morning into this afternoon as sfc hi pres drifts out over the
ocean and ahead of the weak sfc lo pres approaching from the
SSW. Models showing only moderate speed increases over most of
the waters...w/ the highest speeds anticipated invof the lower
Bay...on the sound and over the ocean by late today/this evening.
Have made a few adjustments to the SCAs...confining them to the
hi prob areas list in previous sentence. Winds become SSW
tonight then WSW Thu (at generally diminished speeds)...w/ SCAs
to eventually be confined to the nrn ocean (Thu) due to seas
near 5 ft. Hi pres builds into the region late Thu into Fri
before another system approaches the region late Fri into Sat. A
stronger cold front likely impacts the region by the second
half of the weekend.


MD...Winter Weather Advisory until 3 PM EST this afternoon for
Winter Weather Advisory until noon EST today for MDZ022>024.
VA...Winter Weather Advisory until 6 PM EST this evening for VAZ048-
Winter Weather Advisory until 3 PM EST this afternoon for
Winter Weather Advisory until noon EST today for VAZ060-
MARINE...Small Craft Advisory from 3 PM this afternoon to 11 AM EST
Thursday for ANZ650-652-654.
Small Craft Advisory from 6 PM this evening to 6 AM EST
Thursday for ANZ656-658.
Small Craft Advisory until 6 PM EST this evening for ANZ632-
Small Craft Advisory until 4 PM EST this afternoon for ANZ633.


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