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Area forecast discussion
National Weather Service Wakefield Virginia
300 am EDT Tue Aug 20 2019

Synopsis...
a weak trough of low pressure will persist across the area today.
A strong cold front moves across the area Thursday night then
stalls across North Carolina Friday. High pressure builds into
the area for the weekend.

&&

Near term /today and tonight/...
as of 300 am EDT Tuesday...

Latest msas has high pressure centered near pit with a sfc trof
extending along the i95 corridor across the nern states down to
the Virginia/NC Piedmont. Models show little movement in synoptic features
today as the high to the NW prevents a frontal boundary from sagging
much farther south than the Mason-Dixon line.

Todays forecast will be much like Mon, so will continue the trend
of a pt sunny and hot day with isltd-sct aftrn/eve convection dvlpng
along the sfc trof and psbly LCL sea breezes. Only diffference today
will be for high temps to be a few degrees lower than Mon. Highs low
to mid 90s except 85-90 at the beaches. Dew points in the low to mid
70s yields heat index values btwn 98-103, highest over the Piedmont.

Storm Prediction Center has most areas north of the Virginia/NC border in a marginal svr risk.
Main threat will be for strong wind gusts, but slow moving storms
may produce lclly heavy downpours and freq lightning given the local
conditions. Storms slowly dissipate after sunset due to loss of htng
but will keep chc pops going thru the evening. Otw, pt cldy, warm
and humid once again with lows in the low-mid 70s.

&&

Short term /Wednesday through Thursday night/...
as of 300 am EDT Tuesday...

Models coming in a bit cooler Wed due to more cloud coverage. Once
again, diurnal convection develops on the sfc trof/LCL sea breezes
with the highest pops out acros the Piedmont. Highs Wed arnd 90. Pt
cldy Wed nite with eve convection dissipating. Lows low-mid 70s.

A cold front approaches from the northwest thurs, but does not enter the
local area until after 21z. Thus, thurs starts out with enough
heating for temps to rise back into the low-mid 90s before aftrn
convection develops. Maintained chc pops for now (highest across
the piedmont). The cold front slowly crosses the area thurs nite
along with a wind shift to the north behind it. Will maintain high
chc pops for now with lows upr 60s-mid 70s.

&&

Long term /Friday through Monday/...
as of 300 am EDT Tuesday...

Model consensus continues to show the front stalling across srn
Virginia by 12z Fri, while the 12z/19 GFS continues to forecast the
front to clear the area by late Fri am. On the other hand, the
latest European model (ecmwf)/Gem both have the front moving very slowly southward
across the area on Fri before clearing the area sometime this
weekend. The cold front potentially stalls (or very slowly moves
southward) from Fri-next weekend. If the European model (ecmwf)/Gem solution
verifies and the front slowly moves across srn portions of the
County Warning Area from Fri through the weekend, this would lead to continued
chances of scattered aftn- evening convection across srn Virginia/NE
NC. Far northern portions of the County Warning Area likely remain dry next
weekend (or see only isolated, diurnally- driven showers/tstms)
as sfc high pressure over the Great Lakes/northeast tries to
build toward the region. For now, went with a model blend and
have 20-50% pops on Fri/Sat (highest S/lowest n). Dry/comfortable
wx prevails late sun-early next week as sfc ridging continues to
build over the area.

Highs mainly in the low-mid 80s through the extended period with
lows in the 60s (except around 70f in coastal southeast Virginia/NE nc).

&&

Aviation /07z Tuesday through Saturday/...
as of 130 am EDT Tuesday...

VFR conditions expected through the forecast period as high pressure
dominates. Ptchy fog is possible in areas away from the water towards
sunrise. A sfc trof will persist across the area which should be the
trigger for aftrn/eve convection. Kept thunder out of the tafs attm,
but did note scattered-broken cumulus after 21z. Any storm could produce gusty
winds, MVFR cigs, reduced visibilities in hvy downpours and fqt lightning.

Outlook...
chance for diurnal convection conts Wed then increases Thu as a cold
front approaches from the northwest. The potential for showers/tstms could
linger into Fri if the cold front slows down or stalls over the rgn.

&&

Marine...
as of 300 am EDT Tuesday...

No headlines are anticipated through mid-week. For today and
Wednesday, expect S to SW winds around 5 to 15 knots. Seas will
generally range from 2 to 3 feet and waves in the Bay 1 to 2 feet.
By Wednesday evening, winds and seas will be on the increase as a
cold front approaches the region from the west. SW winds increase to
around 15 to 20 knots ahead of this front, and seas will likely
build to 4 to 5 feet (especially out 20 nm). As a result, small
craft advisories may be needed for at least portions of the Bay and
coastal waters late Wednesday into Thursday. By Friday, the front
clears the area, allowing for winds to become northwest to north and diminish
to around 5 to 15 knots. Onshore flow is anticipated on Saturday and
Sunday.

&&

Akq watches/warnings/advisories...
Maryland...none.
NC...none.
Virginia...none.
Marine...none.

&&

$$
Synopsis...mpr

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