Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 012100
Area Forecast Discussion
National Weather Service Wakefield VA
400 PM EST Thu Dec 1 2016
High pressure slowly builds into the Mid Atlantic tonight through
Sunday. Low pressure passes south of the region Sunday night into
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
The current surface analysis as of 19z indicates 991mb
low pressure over srn QB associated with a vertically stacked
system, and 992mb low pressure over the Gulf of Maine. Meanwhile,
1021mb high pressure is centered over the Lower Mississippi Valley.
This is resulting in westerly flow locally at the surface, with
zonal flow aloft. Temperatures are cooler behind the cold front that
moved offshore earlier this morning, but still above seasonal
averages with downslope flow and a lack of CAA, with aftn values
averaging from 60-65F, with dewpoints in the low/mid 30s. High
pressure will gradually build across the Southeast Conus tonight.
Mostly clear and dry tonight with lows in the mid/upper 30s (locally
low 40s for SE coastal locations).
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Dry conditions will continue to prevail Friday into
Saturday as wnw flow dominates across the region. A trough will pass
north of the area Friday night and will allow CAA to improve. Mainly
clear conditions are expected with high pressure gradually building
in from the wnw. Forecast highs Friday are in the mid/upper 50s,
which are near seasonal averages. Lows drop into the low/mid 30s
Friday night, with highs trending below normal Saturday with
forecast values in the upper 40s to low 50s.
High pressure becomes centered over the Mid-Atlantic region Saturday
night into Sunday. A split flow pattern develops aloft, with a srn
stream system tracking into the Lower Mississippi Valley, and a nrn
stream wave diving into the Great Lakes. This will result in dry
conditions Saturday night, with a mostly clear sky Saturday evening,
followed by increasing clouds later Saturday night, and then mostly
cloudy by Sunday. Forecast lows Saturday night range from the upper
20s to low 30s inland to the mid/upper 30s for se coastal locations,
with highs Sunday in the upper 40s to around 50.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --High pressure over the Mid Atlantic States will loosen its grip
Sunday night. Mid level moisture will increase Sunday night and
early Monday over the area. Support for precipitation is rather
disorganized bur for now kept 30 percent POPs for light rain late
Sunday night. Any precipitation should move quickly off to the
southeast Monday morning.
An upper level trough will move out of the southern Great Plains and
form a surface low over the Lower Mississippi Valley Monday night.
This low will northeast through the Tennessee Valley and emerge east
of the mountains over Maryland or southern Pennsylvania.
Chances for rain begin to develop from the southwest Monday night.
There will be a good chance for rain across the area Tuesday with
this system. A consensus of the models place a likelihood for rain
on Tuesday. Models have had some difficulty with the timing of this
system and five days out chose to go no higher than 50 percent POPs
for now. A strong cold front moves through the area Thursday from
the west and this will bring another chance for rain.
High temperatures will start a bit below normal Monday and warm up
slowly the rest of the week. Highs Monday 50 to 55 will range from
the mid 50s to lower 60s by Thursday. Lows are forecast to range
through the 30s Tuesday morning and in the upper 30s to mid 40s
Thursday and Friday mornings. Following the cold front Thursday...
somewhat colder temperatures are likely.
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.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
High pressure builds across the Southeast States this afternoon
through tonight and Friday. This will bring dry and vfr
conditions. A wnw wind will average 8-12kt this afternoon,
diminish to ~5kt tonight, and then increase to 8-12kt again
Friday. A weak trough passes north of the region Friday night,
with high pressure building into the region Saturday and Sunday.
This will maintain dry and vfr conditions. Weak low pressure
pushes across the Southeast Sunday night into early Monday
bringing a chc of rain. A complex low pressure system potentially
affects the region Monday night into Tuesday bringing a better chc
-- Changed Discussion --Low pressure over southeast Canada and high pressure over the Lower
Mississippi Valley were keeping winds from the west and northwest
but under SCA criteria. A secondary surge will increase winds from
the northwest late Friday night and Saturday and SCA will likely be
needed at that time...especially over inland waters.
Winds diminish Monday and then turn to an easterly component Tuesday
ahead of a low pressure system that will move northeast from the
Lower Mississippi Valley. Seas may build to around 5 feet in the
outer portion of the coastal waters around mid week.
-- End Changed Discussion --&&