Scientific Forecaster Discussion
fxus61 kakq 230810
Area forecast discussion
National Weather Service Wakefield Virginia
410 am EDT Mon Oct 23 2017
a cold front will approach from the west today...then slowly
push through the local area on Tuesday. High pressure builds
across the Gulf of Mexico Wednesday and Thursday...as low
pressure lingers from the Great Lakes to New England.
Near term /until 6 PM this evening/...
fog has become widespread/dense invof I 95 corridor and points east
in interior ern/southeast Virginia and NE NC...so raised a dense fog advisory
through 13z this morning. Watching other areas east of the
sfc hi pres has shifted to east of ern New England...while lo pres
and an associated cold front were slowly pushing east through the
Ohio/Tennessee valleys. Fog is again a concern early this morning...and
has become a bit more widespread in coverage as compared to the
past few mornings. Lo level mixing remaining limited (early)
this morning...then increase (as southeast winds increase/become gusty)
by late morning/afternoon. Another warm/mainly dry day...though
increasing pops late (well) west of I 95. Highs in the u70s-around
80f central and (interior) east to the l-m70s west (where clouds
begin to thicken in the afternoon) and at the immediate coast.
Short term /6 PM this evening through Wednesday/...
latest 00z/23 GFS/NAM/ECMWF remain fairly similar W/ the
overall timing of the next cold front...now depicting the best
lift/forcing for likely to categorical pops (60-90%) from about
06z/Tue through 18z/Tue (lingering into Tue evening along the
ern shore). Strong low level jet and sfc dew pts in the
60s...will allow for some locally heavy downpours and possible
isolated tstms by late Mon night/Tue morning...mainly for
far srn/southeast Virginia-NE NC. Instability markedly limited (and generally
confined to far srn/southeast and near the immediate coast) despite
increasing low level winds. Storm Prediction Center has slight risk severe for south-southwest parts
of the local area (shifting to the ern shore Tue morning). Hi
res models depict a few bands of convection (which
weaken/gradually break up) moving into the region from the west-southwest
tonight...continuing to the coast Tue morning.
Partial clearing expected Tue by late morning west and by late
aftn east...and have continued W/ lowering pop trend W-E. Still
mild through Tue W/ lows Mon night in the 60s...then highs tues
in the 70s to near 80 f southeast as cold air lags well behind off to
the northwest of the local area.
Cold front reaches the coast early Tue night and is expected
to exit the coast by daybreak Wed morning. Any rain tapers/ends
at the coast Tue evening. Temperatures falling from the 60s in
the evening to 50f inland and upper 50s closer to the coast by
Wed morning. Dewpoints also fall from the lower 50s northwest to lower
60s southeast in the evening to 40-45f inland and 45f to around 50f by
morning. On Wed...local area looks to remain in between the sfc
cold front well offshore and deeper moisture/cold pool aloft to
our west-northwest. Cooler Wed W/ highs mainly in the M-u60s.
Long term /Wednesday night through Sunday/...
dry conditions Wed night as exiting cold front moves well
offshore. Upper level trough swings through the region Thu
morning...mainly kick off isolated -shras (mainly delmarva) Thu
morning. Otherwise, dry conditions prevail Thu through at least
Sat as sfc high pressure builds in from the SW Thu and shifts
off the mid Atlantic coast during Fri. The high then tracks up
off the New England coast for Sat. Model consensus diverges Sat
night into sun. European model (ecmwf) has a coastal low developing near the
area...while the GFS not only has a coastal low developing near
the area but also a deepening sfc low over the Great Lakes
region into Ontario. Incoming precip differs greatly between
models, therefore have leaned closer to climatology during this
Temperatures at to slightly below normal for Wed night with
lows in the 40s (upper 30s possible far northwest counties). Temps
slow to rebound on Thu as upper trough swings through and more
stable northwest flow aloft develops over the area. Highs 60-64f. High
pressure slides into the region Thu night and then temperatures
slowly moderate. Lows Thu night in the 40s (around 50f beaches).
Seasonal normal highs Fri in the upper 60s to around 70f. Lows
Fri night in the upper 40s inland to 50-55f immediate coast.
Highs Sat in the lower 70s (upper 60s beaches). Lows Sat night
generally in the 50s (upper 40s eastern piedmont). Highs sun
generally in the upper 60s to around 70f (mid 60s eastern
Aviation /08z Monday through Friday/...
sfc hi pres has shifted to off of ern New England the past 12-18
hours...while lo pres and an associated cold front moves into
the Ohio/Tennessee valleys. Fog is once again a concern...mainly at
sby/phf/ecg W/ another round of vrb cigs/vsbys...and will likely
persist through the early morning hours. VFR conditions and
increasing mid/high clouds are expected to prevail after
13z/23...W/ a southeast wind increasing to 10-12kt...gusts up to 20 kt
possible during the aftn/eve. A cold front is expected to track
through the region tonight into Tue morning. This front will
bring the potential for MVFR/IFR conditions in rain and lo ceilings.
Mainly VFR Tuesday aftn/evening through Fri.
a cold front will approach the region allowing for increasing winds
through the day today. Southeast winds will start out around 10
knots this morning, increasing to 15 to 20 knots by this evening as
the front approaches.
The cold front and associated low pressure areas will approach from
the west tonight and push across the waters Tuesday night into
Wednesday morning. The pressure gradient will lead to increasing southeast
and then S flow ahead of the front this evening through Tuesday
morning. Winds shift to the west-northwest behind the front Tuesday night into
Wednesday morning. Small craft advisories are in effect for all of
the waters Monday night through Tuesday afternoon (for the rivers)
and lingering into Tuesday evening for the chesepeake Bay and
Currituck Sound. Small craft advisories over the coastal waters will
continue through Wednesday. South winds of 15 to 25 knots with
higher gusts will occur Monday night into Tuesday evening.
Seas will build to 5 to 9 feet with waves of 3 to 4 feet in the Bay.
Winds become west to northwest at 10 to 15 knots behind the front
Wednesday night through Thursday. High pressure builds back into the
NC...dense fog advisory until 9 am EDT this morning for ncz012>014-
Virginia...dense fog advisory until 9 am EDT this morning for vaz064-075-
Marine...Small Craft Advisory from 10 PM this evening to 7 PM EDT
Wednesday for anz650-652-654-656-658.
Small Craft Advisory from 10 PM this evening to 1 PM EDT
Tuesday for anz635>638.
Small Craft Advisory from 4 PM this afternoon to 5 PM EDT
Tuesday for anz630>632-634.
Small Craft Advisory from 10 PM this evening to 7 PM EDT
Tuesday for anz633.