Area forecast discussion
National Weather Service Wakefield Virginia
1031 am EDT Monday may 20 2013
Synopsis...
a weak front has pushed north of the area as high pressure becomes
anchored well off the coast. Above average temperature will prevail
through much of the upcoming week. A cold front will pass through
the Middle Atlantic States late Thursday into early Friday...with
cooler temperatures expected by next weekend.
&&
Near term /through tonight/...
upper level trough continues to our west across western Virginia and
West Virginia as depicted well by enhanced infrared imagery. Scattered
showers and a few thunderstorms extending from south central Virginia south
across central North Carolina into eastern South Carolina. Despite a
northeastward cell movement...showers have tended to dissipate over
southern Virginia. Around 14z...convection began to increase over from
Southampton County Virginia into northeast North Carolina. Showers and
thunderstorms will be most widespread over southern portions of the County Warning Area
with likely probability of precipitation in place. High temperatures will be near 80 across
the County Warning Area except low to middle 70s near the coast.
Precipitable water continues in the 1.5 to 1.8 inch range so locally
heavy rainfall will be possible. This is not expected to be widespread
as Omega is weak below 10k feet.
Showers and thunderstorms will continue into early Monday evening
diminishing to widely scattered showers overnight. Patchy fog will
be possible on the Eastern Shore and the Northern Neck. Low temperatures
will be in the middle to upper 60s.
&&
Short term /Tuesday through Wednesday night/...
conditions fairly similar to Monday will persist Tuesday into
Wednesday. S/south-southwest winds will draw warm and moist air from the
south...and coupled with marginal instability...will create
favorable conditions for shower and thunderstorm development.
Precipitation coverage will wane each evening as the instability
decreases. Temperatures are forecast to top out in the middle to upper
80s in most areas with upper 70s to lower 80s near the coast and over
the lower Eastern Shore.
&&
Long term /Thursday through Sunday/...
long term period starts off Wednesday night with a chance for rain...mainly
west of I-95...ahead of an approaching middle-level trough and associated
cold front. S/SW flow will keep temperatures above normal...with lows in the
middle to upper 60s. This pattern continues into Thursday/Thursday night with still a
30-40% chance for shwrs/tstms. Deep-layer moisture is abundant however
forcing is a limiting factor due to a lack of warm air advection and most short wave
energy staying off to the north. Models have continued to speed up
the timing of the front...with the frontal passage now expected to be sometime
late Thursday/Thursday night. Highs Thursday in the low to middle 80s. Behind the front Friday
into the weekend...diminishing chances for rain and slightly lower temperatures
(but still around seasonal norms) with highs in the middle 70s to lower
80s and lows in the 50s.
&&
Aviation /14z Monday through Friday/...
IFR conditions have developed this morning from a krwi to kxsa
line westward. Think this will persist through 14z-15z...aided by
area of showers lifting northeastward out of central NC. Also...IFR/LIFR has
persisted since 06z at ksby...but conditions should improve by
13z. Elsewhere...VFR conditions have prevailed overnight.
For the most part...expect today to be VFR. However...increased
amount of sunshine expected today should allow more thunderstorms to develop
east of I-95...affecting kphf/korf/kecg during the afternoon
hours. Tempo group added to taf. Heavier showers/thunderstorms will cause
brief IFR conditions. Think thunderstorm potential less at ksby and...due
to morning shower activity...at kric. Expect tonight to have mainly
VFR/MVFR conditions...but potential does exist for IFR to develop
after 07z.
Mainly VFR in the Tuesday to Thursday time frame...with the potential for
isolated/scattered showers and thunderstorms both Tue/Wed. More widespread shower/thunderstorm
activity expected Thursday along/ahead of next cold front...which moves across
the area Thursday/Thursday night.
&&
Marine...
S/south-southeast winds continue all areas this morning...as high pressure surface
and aloft prevails off the East Coast. This general pattern will
continue into Thursday. Winds expected to be in the 10 to 15 knots
range on the Bay...and around 15kt on the ocean during most of this
period. Thus...no scas are anticipated through Tuesday. Current Small Craft Advisory
for seas on the northern coastal waters will be allowed to expire at
4 am. Seas near 20 nm will continue to flirt with 5
feet...especially on the northern coastal waters. However...a slow
subsiding trend is expected. Scattered showers/thunderstorms expected today and
tonight...with a slow decrease in coverage northern areas on
Tuesday.
Next frontal boundary will move into/across the area in the Thursday/Friday
time frame. Latest GFS suggests there will be 2 frontal
passages...one late Thursday...the second stronger one late Friday.
Showers/thunderstorms expected to accompany both fronts. Winds behind second
boundary likely to reach/exceed Small Craft Advisory criteria for several hours after
frontal passage.
&&
Akq watches/warnings/advisories...
Maryland...none.
NC...none.
Virginia...none.
Marine...none.
&&
$$
Synopsis...lkb/lsa
near term...dap/lsa
short term...dap/lsa
long term...mas
aviation...worse
marine...worse
