Scientific Forecaster Discussion
fxus61 kakq 212101
Area forecast discussion
National Weather Service Wakefield Virginia
401 PM EST sun Jan 21 2018
high pressure remains centered over the southeast states today
into Monday. A cold front crosses the region Tuesday morning
and moves well off the coast by Tuesday night. High pressure
becomes centered over the south central states Wednesday and
builds east into the local area by Thursday.
Near term /through Monday/...
latest analysis indicates a weak upper level trough along the southeast
coast with a lot of clouds over the Gulf Stream off the Carolina
coast. A much stronger storm system is moving NE through the
plains states bringing a powerful winter storm to much of the
central Continental U.S.. over the local area, weak sfc high pressure
remains in control with dry conditions and sunny skies over the
east and partly/mostly cloudy skies moving into central/south
central Virginia. Quite warm with inland temperatures into the mid 60s
while areas near the coast are mainly 55-60f. For tonight,
skies will avg partly- mostly cloudy north to partly cloudy- mostly
clear S. Not as cold, with a light southerly flow and more
clouds/higher dew pts than past several nights. Expect lows
mainly from 35-40 f over the interior southern zones to 40-45f
Sfc high pressure remains off the southeast/mid-Atlc coast through Mon
while low pressure tracks from the Central Plains to the wrn
Great Lakes. South-southwest flow will keep mild wx over the region W/
partly cloudy conditions. Highs upper 50s/lower 60s near the
Bay/ocean and on the ern shore to the mid 60s for most other
Short term /Monday night through Wednesday/...
rain chances increase quickly after midnight Mon night through
Tue morning as main sfc low pressure tracks through the Great Lakes
region...pushing its associated cold front across the local
area by Tue aftn. Models remain in good general agreement wrt
timing that front through the forecast area. Still see potential for at
least isolated tstms in a high shear/Low Cape environment (and
sherb parameters to >1 from about 09-18z/Tue across the County Warning Area.
Keeping likely to categorical pops for the area during 06z-
17z/23 (tue) then pcpn moving out of the entire area by 00z/24
(wed). Highs Tue from the mid 60s north and on the ern shore to the
u60s-l70s southeast. Dry cooler Tue night/Wed with lows mainly in the
30s and highs Wed upper 40s north to lower 50s S.
Long term /Wednesday night through Sunday/...
medium range period (late week into next weekend) characterized by
building upper level ridge building over the eastern half of the
Continental U.S.. starting off seasonably cool behind the cool front on
Thursday...then steadily warming as surface high pressure builds
over the area on Friday, sliding offshore late Friday and Saturday.
Highs in the upper 30s to mid 40s Thu/Fri warm back into the 50s
Saturday...and well into the 50s to 60s by Sunday.
Remaining dry through the Saturday night. Rain chances increase by
late next weekend, as an amplifying upper trough over the plains is
forecast to lift across the plains from the Desert Southwest
Fri/Sat. Gulf is wide open during this time frame, and expect llvl
moisture to surge north into the area ahead of this feature, with a
period of showers late next weekend. Worth noting that there is good
to excellent agreement among the gefs/eps early next week, as both
show temperatures dropping back quickly behind the associated cold
front into early next week.
Aviation /21z Sunday through Friday/...
VFR conditions will continue through the 18z taf period with
weak sfc high pressure over the area. Clouds are increasing and
will see cigs of 5-10k ft affecting much of the area through
tonight. Light S winds inland with light east-northeast winds at the coast
this aftn, mainly south-southwest at 5 kt or less tonight. Sfc high pressure
settles off the southeast coast on Mon W/ dry conditions continuing.
The next chance for widespread precipitation and flight
restrictions comes mainly after midnight Tue through Tue aftn
with a passing cold front. Gusty south-southwest winds early Tue shift to
the west-northwest late in the day. Isolated tstms possible with the front
mainly Tue morning. Dry and VFR conditions then prevail Tue-Thu.
Ridge of surface high pressure will linger over the region through
tonight, and remain in control of the weather thru Monday. Latest
obs/buoy reports winds have veered around to the east-southeast this aftn 10
kt or less W/ generally benign boating conditions. Surface high will
slide offshore Monday into Monday night, as low pressure moves
across the mid-Mississippi Valley into the Great Lakes. By Monday
night, winds will begin to increase again out of the south as the
Great Lakes low pushes its associated cold front toward the region.
Wind will increase to 15 to 25 kt from the S-SW prior to daybreak
tues, continuing thru midday, with seas on the coastal waters
building to 4-6 ft; waves 3-4 ft on the Bay.
Scas have been hoisted across all waters for Monday night through
Tuesday/Tuesday night. Some gale force gusts possible along and just
ahead of the frontal passage. However, expect that these gusts will
likely be convective in nature. As such, will go ahead with Small Craft Advisory and
mention potential pre-frontal in the mww. Once the front clears the
area Tuesday afternoon, winds veer around to the west 10-15 kt tues
night/Wed and then northwest on Thursday. Waves/seas subside to 1-3
Marine...Small Craft Advisory from midnight Monday night to 6 PM EST
Tuesday for anz630>632-634>638.
Small Craft Advisory from 6 am to 6 PM EST Tuesday for anz633-
Small Craft Advisory from midnight Monday night to midnight
EST Tuesday night for anz650-652-654.