Area forecast discussion
National Weather Service Wakefield Virginia
819 PM EDT Tuesday may 21 2013
Synopsis...
the combination of high pressure over the Atlantic and southwest
winds will continue to pull a warm and humid airmass into the region
through Thursday. A cold front will pass through the middle Atlantic
Thursday night. High pressure returns to the area Friday into the
weekend with drier conditions and cooler temperatures expected.
&&
Near term /until 6 am Wednesday morning/...
showers have come to an end across southeast Virginia and NE NC...and the only
remaining showers are just off the Virginia Beach coast. This area
of showers is expect to die out in the next 1 to 2 hours with the
loss of daytime heating. Skies are mostly clear for most of the forecast area
except for some high cirrus streaming down into far northwest counties
at this time from the north.
For overnight...the combination of ample low level moisture and
clearing this evening will result in the development of low
stratus after midnight tonight. Once again...S-SW winds at or
above 5 knots will prevent fog from forming. However if any
observation sites report visibilities lower than 7 statute
miles...the obscuration will likely be more haze than fog/mist
(very similar to Monday night). Temperatures will remain well above
normal tonight with lows in the middle to upper 60s.
&&
Short term /6 am Wednesday morning through Friday/...
similar pattern as last couple days will continue into Wednesday. SW
flow aloft resumes after a middle-level low pushes offshore tonight.
Deep layer moisture will then slowly increase Wednesday into Wednesday night
ahead of a low pressure systm passing through the Great Lakes region. Did
include a slight chance for a shower/thunderstorm Wednesday afternoon/eveng with a warm and
moist airmass in place...however most areas should remain dry due to
a lack of forcing. Otw...expect a prtly cloudy sky with highs in the
middle 80s.
For Thursday...cold front approaches from the Ohio Valley...and rain
likely with increasing moisture and short wave energy aloft. Up to a half
inch of precipitation possible with the best chance for rain in the afternoon. Hi
temperatures genrly in the low 80s. Readings will be a bit cooler near
the coast. The rain will end from west to east Thursday night/Friday morning as
the cold front advances off the coast. Not expecting skies to
completely clear out...with moisture still in place aloft following
the surface frontal passage.
Drier conds expected by Friday afternoon as flow becomes northwesterly for the
first time in several days...and temperatures only reaching the middle 70s
in most locations.
&&
Long term /Friday night through Tuesday/...
Canadian high pressure builds into the area from the northwest Friday night. Clearing
& cool with decoupling winds inland. Coastal winds stay mixed due to low
prs slowly pulling away to the NE. Lows M-u40s from i95 on west...
near 50 in vicinity of ches Bay and l-m50s at the coast.
Sunny & pleasant Sat with 500 mb ridge ovrhd. Highs in the l-m70s xcpt
60s at the beaches. Pt cloudy Sat night as some high level moisture ovrsprds
region. Lows 50-55. Pt sunny and a bit warmer sun. Highs M-u70s xcpt
65-70 at the beaches.
Tricky forecast Erly next week. Models now increasing moisture due to combo of
onshore east-southeast flow and warm front apprchg from the SW. Appears best
sprt for probability of precipitation will be across southern & western Virginia/northern NC Monday & Monday
night. Kept slght chance probability of precipitation on Tuesday for now given the low confidence
this far out. Highs Monday l-m70s. Lows 55-60. Highs Tuesday M-u70s.
&&
Aviation /00z Wednesday through Sunday/...
showers and thunderstorms have ended across southeast Virginia and NE NC this
evening. Next concern will be the formation of IFR stratus
overnight. Latest guidance has ceilings becoming IFR at all taf sites
except kecg between 06-08z Wednesday morning and continuing through
14-15z. Will maintain MVFR ceilings for kecg overnight. Conditions
will slowly improve Wednesday morning. An isolated shower or
thunderstorm is possible Wednesday afternoon.
Outlook: IFR stratus will be possible again Thursday morning. More
widespread convection is expected Thursday afternoon and evening as a
cold front approaches. The weather improves late Friday and beyond
following a cold frontal passage.
&&
Marine...
no headlines in short term as winds remain S-SW at or below 15kt through Wednesday.
Some channeling up the Bay as well as seas apprchg 5 feet out near 20 nm
in vicinity of buoy 44009 by Wednesday night...but confidence not high enough to go
with a sustained Small Craft Advisory so will hold off on headlines at this time. Sca's may
eventually be needed for seas over northern coastal waters.
Cdfrnt crosses the waters late Thursday night Friday with low prs moving north
along it. Will have to monitor prs gradient between this low and strong
high prs building in from the northwest for possible Small Craft Advisory cndtns Friday into Friday evening.
Otw...high prs builds into the area over the weekend with sub Small Craft Advisory
cndtns expeceted both Sat and sun.
&&
Akq watches/warnings/advisories...
Maryland...none.
NC...none.
Virginia...none.
Marine...none.
&&
$$
Synopsis...bmd/mas
near term...bmd
short term...mas
long term...mpr
aviation...jdm/lsa
marine...mpr
