Area forecast discussion
National Weather Service Wakefield Virginia
128 am EDT Thursday may 23 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 into Friday morning. High pressure returns to the
area late Friday into the weekend with drier conditions and cooler
temperatures expected.
&&
Near term /until 6 am this morning/...
update...isolated showers have ended across far southeast Virginia and NE NC
while showers and a stray thunderstorm are continuing in the
Piedmont.
Mainly dry conds for the overnight hours across the eastern half of
the County Warning Area. Temperatures remain well above normal tonight as southerly flow
persists...lows in the upper 60s under a prtly to mostly cloudy sky.
Patchy fog is possible but more in the way of low stratus is
expected. Chances for rain will increase Thursday morng as moisture and
middle-level energy embedded in the SW flow aloft increases.
&&
Short term /6 am this morning through Saturday/...
chances for rain will increase through the day Thursday as deep layer moisture
increases and low pressure approaches from the west. Not expecting
widespread severe weather however an isolated damaging Wing gust is possible as
shear profiles increase ahead of an approaching middle-level trough.
Don't expect it to rain the entire day however coverage is enough to
warrant likely (70%) probability of precipitation. Best timing for heavy rain will be in
the afternoon/Erly evening hours as moisture increases and the middle Atlantic
sits under the right entrance region of an upper-level jet streak. Hi
temperatures genrly in the low 80s. Readings will be a bit cooler near the
coast. The rain will end from west to east Erly Friday 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 (though keeping a chance for showers
over eastern areas with the upper-level trough still west of the area) as
surface flow becomes nwrly for the first time in several days...and
temperatures only reaching the low to middle 70s in most locations. Surface hi
pressure builds in from the west on Sat leading to a mostly sny sky and
noticeably cooler temperatures (highs only in the low to middle 70s).
&&
Long term /Saturday night through Wednesday/...
medium range forecast period characterized by modified Canadian high
pressure dropping northwest to southeast across the area for the latter half of
the Memorial Day weekend. Aloft, closed upper level low over the
northeast and Atlantic Canada will slowly lift NE Sunday, allowing
for modest height rises aloft, and with it a general incremental
ramping up of temperatures through the period. It will also allow for
northwest flow aloft across the southern middle-Atlantic Sunday and
Monday. Low (slight chance) probability of precipitation remain in place for Memorial Day
afternoon/evening as a weak disturbance/middle level trough drops across
the region and a surface warm front lifts north to the west.
Bermuda high/Summer-like pattern reloads for the middle to latter
potion of the week, as middle-upper level ridging rebuilds across
the eastern half of the Continental U.S. And surface high slides offshore. Rainfall
opportunities will primarily be diurnally driven Monday-Wed, with
little more than partly cloudy and increasingly muggy conditions
by night.
&&
Aviation /06z Thursday through Monday/...
clouds have scattered out across the local area this evening...so
will continue with VFR conditions through early Thursday morning.
Same as the last few nights...am expecting a low stratus deck to
develop after 06z with IFR conditions likely.
A slow lifting of the cloud deck is expected Thursday morning. A cold
front approaches from the west during the afternoon...but pre-frontal
showers may start as early as 15z. Isolated T-storms are possible
Thursday afternoon.
Outlook: front pushes off the CST during Friday...with lagging upper
trough not moving offshr until late Friday night. So...there could be
lingering lower ceilings and visibilities from scattered precipitation right through Friday night. VFR
conditions should return for Sat and definitely sun...as high pressure
builds into and over the region.
&&
Marine...
Small Craft Advisory for the Bay and northern coastal waters has begun and
continues into Thursday night. Winds/waves/seas slowly ramp up as
pressure gradient tightens between Bermuda high and approaching
cold front to the west. As gradient continues to tighten...guidance
continues to show seas ramping upward into Small Craft Advisory range over southern
coastal waters late Thursday afternoon and evening. Have went ahead
and hoisted the Small Craft Advisory for the southern coastal waters (south of cape
charles) with this evening's package.
Front will cross the waters late Thursday night/early Friday through Friday
afternoon...with a strong north-northwest surge of winds (~20 knots and gusty)
expected Friday through early Saturday. Small Craft Advisory flags are likely to be
needed through this period...with conditions to become sub-Small Craft Advisory with
winds diminishing at or below 15kt Sat afternoon through Monday as high
pressure builds across the waters over the Holiday weekend.
&&
Akq watches/warnings/advisories...
Maryland...none.
NC...none.
Virginia...none.
Marine...Small Craft Advisory until midnight EDT tonight for anz630>632-
634.
Small Craft Advisory until 7 am EDT Friday for anz650-652-654.
Small Craft Advisory from 4 PM this afternoon to 7 am EDT
Friday for anz656-658.
&&
$$
Synopsis...bmd/mas
near term...bmd/dap
short term...mas
long term...mam
aviation...jdm/mpr
marine...jdm/mam
