Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
229 PM EDT Friday may 24 2013
Synopsis...
an upper level low will lift northeast of the area through
tonight. Canadian high pressure builds in for the Memorial Day
weekend. A warm front is expected to move through on Tuesday.
&&
Near term /through Saturday/...
cold front is off the middle-Atlantic coast. Much cooler and windy
conditions have been the rule of the day with cold advection
occurring.
Upper trough has dropped from the lower Great Lakes into the
northern middle Atlantic. Potent vorticity maximum rounding the base of the
low has supported scattered to numerous showers near the I-95
corridor throughout the day...but at 18z most of those had moved
east of the Bay. Low level moisture and cloud cover have been
hanging tough although visible imagery shows breaks in the clouds
developing over the central Virginia foothills.
Have generally trimmed probability of precipitation for showers for the rest of the day
although some high resolution guidance suggests a few showers move
through northeast Maryland early this evening. Confidence is low
but allowed for isolated showers in this area this evening.
Otherwise...clouds will break up this evening as the upper
trough/low shift northeast of the County Warning Area and this paves the way for
decent clearing overnight.
While gusts will diminish some this evening...winds will not
decouple given tight gradient under a cold advection regime. This
will keep temperatures from falling like a rock but the air mass
change itself will bring a chilly night. With wind do not expect
frost issues...but minima in the lower 30s over The Highlands
supports the freeze warning.
Sunshine will make a return on Saturday but it will be another
windy day as low pressure deepens off the New England coast and
high pressure builds in from the west. Winds may be similar to
Friday. Saturday will be another below normal day for temperatures
as well...however with sunshine and downsloping flow this should
help boost temperatures in the upper 60s for most areas except the
higher elevations.
&&
Short term /Saturday night through Monday/...
Canadian high pressure builds in for the remainder of the Memorial
Day weekend...moving off the coast on Memorial Day Monday.
Temperatures will moderate through the period...returning close to
climatology Memorial Day. Expect mostly clear skies much of the time but
in a west/northwest flow aloft there may be some high clouds from
time to time.
&&
Long term /Monday night through Friday/...
a warm front is expected to lift north on Tuesday...and models are
in good agreement with an upper ridge building during the middle to
late week. This will allow the warming trend to continue through
the weekend...with maxima likely well in the 80s Wednesday and
beyond. Under the ridge...thunderstorm chances look very low
although there could be a few diurnally driven storms over the
mountains toward the end of the week.
&&
Aviation /17z Friday through Tuesday/...
gusty northwest winds have been the primary impact today...with
occasional MVFR ceilings at The Hubs especially in showers. Showers
have moved east of the Bay...and have dry forecast in for the
valid taf period with VFR conditions. Wind gusts will diminish
tonight...but gusts similar to today are expected on Saturday.
High pressure builds in for the rest of the Memorial Day weekend
for no significant weather.
&&
Marine...
Gale Warning continues into early evening. Showers will clear the
Bay by 19z...but models still suggest gradient wind could gust
around gales through 00z or so. Small Craft Advisory in effect thereafter...and
continues into Saturday night. Could have a period of near gales
on Saturday...but confidence too low to raise at this time.
High pressure builds in for less wind Sunday into early next week.
&&
Lwx watches/warnings/advisories...
District of Columbia...none.
Maryland...freeze warning from 2 am to 8 am EDT Saturday for mdz501.
Virginia...freeze warning from 2 am to 8 am EDT Saturday for vaz503.
WV...freeze warning from 2 am to 8 am EDT Saturday for wvz501-503-
505.
Marine...Small Craft Advisory from 8 PM this evening to 4 am EDT Sunday
for anz530>534-537>543.
Gale Warning until 8 PM EDT this evening for anz530>543.
Small Craft Advisory from 8 PM this evening to 8 PM EDT
Saturday for anz535-536.
&&
$$
Bpp
