Area Forecast Discussion Issued by NWS Wakefield, VA
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FXUS61 KAKQ 170739
AFDAKQ
AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
339 AM EDT Sun Mar 17 2024
.SYNOPSIS...
A weak upper level disturbance crosses the area through this
morning. A cold front will drop through the region tonight
bringing in cooler air for the start of next week. A stronger
cold front will cross the area late Monday into Tuesday morning.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 830 PM EDT Saturday...
The latest WX analysis indicates weak sfc high pressure now off
the VA/NC coast, with a weak sfc trough along the coast of SC.
Aloft, the flow is westerly, with a strong shortwave over the
upper midwest, and weaker shortwave energy over the TN Valley,
moving towards the southern Appalachians. The sky is still
mostly clear across the local area, with a light E-SE flow along
the coast, and light/variable to S winds well inland. Temperatures
have dropped off fast since sunset, with most areas ranging
through the 50s (locally some upper 40s over the typically
cooler sections of interior SE VA/NE NC as well as the eastern
shore). Models show the weaker shortwave passing through the
local area late tonight, which will result in an increase in
clouds, especially over the E and SE portions of the FA closer
to the sfc low/trough that is progged to move NE along the
Carolina coast. In addition, some weak elevated instability
(100-300 J/kg MUCAPE and H7-H5 lapse rates of 6.5 to 7C/Km)
will briefly overspread coastal VA/NC late tonight as the
shortwave passes by. As such, a few showers cannot be ruled out
over the Se 1/2 of the CWA between 2-8 AM. Areal average QPFs
are only a few hundredths of an inch. Overnight lows will mostly
range from the upper 40s to the lower 50s.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 225 PM EDT Saturday...
The strong low pressure system tracks east through Quebec Sun into
Mon, sending a second, stronger cold front across the area Sun night-
Mon. Cloud cover will increase throughout the day ahead of the
mainly dry front. However, there may be a little bit of light rain
Sunday evening into early Monday as a weak shortwave also moves
offshore to our south. Will keep PoPs no higher than 20-30% in SE
VA/NE NC with a dry forecast elsewhere. QPFs are a few hundredths of
an inch at best. Sunday will be the warmest day of the next several
with highs in the upper 60s-lower 70s. Cooler air will begin to
filter in behind the boundary, so low temperatures Sunday night
will be in the mid-upper 30s to the west and mid to upper 40s
to the east/near the coast. Breezy/cooler on Mon with widespread
20-25 mph gusts. Forecast highs are in the mid to upper 50s.
A secondary, stronger shot of CAA arrives Monday night-Tuesday
morning as the flow aloft becomes NW. Breezy (especially near the
coast) Monday night with lows in the upper 20s-30s. Tuesday looks to
be the coolest day of the period with continued breezy NW winds
(gusts up to 30 mph possible near the coast) and highs in the mid
50s (except for lower 50s on the MD ern shore).
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 225 PM EDT Saturday...
The flow aloft flattens out a little bit from Wed-Thu, but the
latest (12z) global models and ensembles still show it remaining
WNW. Temperatures moderate into the 60s (with continued dry wx) for
Wed, but may cool back down a bit on Thu behind another dry cold
front. Still breezy out of the WNW on Wed, with lighter N winds
expected on Thu.
Then, attention turns to our next low pressure system, which will
impact the area sometime between Friday night and Sun/Mon. While
there are major differences in the GFS/ECMWF with respect to timing,
ensemble mean precipitation amounts are 0.50-1.50" across the FA
from Friday (3/22) through Monday (3/25). So, will continue to go
with widespread 40-60% PoPs during this time, which will likely need
to be raised as confidence in exact timing increases in the coming
days (given that ensemble mean QPFs are already > 1"in parts of the
area). Temps remain near to below average from Fri through next
weekend.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
As of 220 AM EDT Sunday...
Mainly VFR conditions are expected at the TAF sites from early
this morning into early Mon morning. However, a shortwave will
cross the area through this morning, which may bring a few
showers to SBY/PHF/ORF/ECG, with the highest chc being at
ECG/ORF. Flight restrictions, mostly from MVFR CIGs are expected
for a few hrs across SE VA/NE NC and have included VCSH wording
at ORF/ECG. VFR after ~13Z this morning for all areas with
winds shifting to the W-WSW and increasing to 10-15 kt (with
gusts to 20 kt).
Outlook: Isolated to widely sctd showers will be possible over
SE terminals (ORF/ECG) with a second, stronger cold front
crossing the region tonight into Mon morning (which may result
in brief flight restrictions). Otherwise, mainly VFR through the
middle of next week.
&&
.MARINE...
-- Changed Discussion --
As of 335 AM EDT Sunday...
Latest analysis shows 1012+mb sfc low pressure offshore of the
southeast coast early this morning. A potent northern stream
~992mb low pressure system was analyzed over eastern Ontario,
with the associated strong surface cold front extending from
Lake Ontario SSW into the eastern OH and Lower TN River Valleys.
Latest obs and buoy reports showing SSW flow 10-20 kt over the
bay, with pressure gradient briefly tightening with weak low
pressure sliding across the region this morning. Expect SCA
conditions currently in place over the lower James and Ches Bay
to quickly ramp down in the wake of this system after 6-7 am,
and will therefore extend SCA through 7am for the lower James
and lower Bay to match the middle bay zones. Otherwise, no major
changes in forecast rationale for today, with winds remaining
W-SW 10-15 kt, occasionally gusting to 18-20 kt in the James
River and lower bay this afternoon.
Winds veer to the N-NW, tonight into early Monday morning, as
the pressure gradient tightens once again ahead of the next
frontal passage. A brief period of SCA is possible with NW winds
over the lower bay. However, SCA headlines are more likely to
be needed Monday evening, as a strong cold front drops across
the waters. Winds quickly ramp up after 00z/8pm over northern
waters, reaching the southern waters by midnight as gusty NW
winds bring much cooler air into the region. Wind probs remain
low for prolonged gale force gusts (<10%), but quite likely to
see solid SCAs appear over the entire area during this
timeframe. Cool high pressure builds south of the area Tue
night, allowing winds to slowly diminish and SCAs potentially
coming down by mid to late Tuesday afternoon. Winds back to the
W-SW winds late Tue into Wed, with potential for a brief period
of SCA conditions Tue night in the lower bay and lower James
River. Another front drops across the area later Wed aftn,
pushing winds back to the NNW Wed night and Thu.-- End Changed Discussion --
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 7 AM EDT this morning for ANZ630-
631.
Small Craft Advisory until 4 AM EDT early this morning for
ANZ632-634-638.
&&
$$
SYNOPSIS...TMG
NEAR TERM...ERI/LKB
SHORT TERM...ERI/TMG
LONG TERM...ERI/TMG
AVIATION...TMG
MARINE...MAM/AM