Scientific Forecaster Discussion
fxus61 klwx 270114
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
914 PM EDT Mon Jun 26 2017
a sharp upper level trough will move across the region on Tuesday.
High pressure builds over the area Wednesday and moves offshore
Thursday. Warmer conditions expected towards the end of the work
week and into the weekend.
Near term /through Tuesday/...
a surface trough persists across the mid-Atlantic region. A few
clouds are across the Baltimore/Washington metros this evening.
Showers have developed in southern PA, right over the Maryland/PA
border. A few showers may pop-up across NE Maryland this evening and
exit by midnight. Showers across the Ohio Valley will approach
the appalachains mtns by Tuesday morning. Showers should taper
off as they move across the mtns as most of the forcing from the
approaching upper level trough lifts northward.
Cool with lows in the 50s except mid 60s in city centers.
A sharp upper level trough will move across the area late
tomorrow. Strong height falls will provide large scale forcing
for showers and thunderstorms to develop. Biggest limiting
factor is lack of low-level moisture and weak instability with
cape values progged at less than 250 j/kg. Best coverage of
showers will be east of the Blue Ridge mtns where instability
will be higher. Showers will only produce very light rainfall
due to relatively high base clouds and a ton of mid-level dry
air. Gusty winds and small hail may be possible due to
inverted-v soundings and very cool temps aloft for this time of
the year. -20c 500 mb temps are progged which is near record low
for late Jun.
Short term /Tuesday night through Wednesday night/...
Trough axis moves east Tue evening with rapid clearing. High
pressure builds for Wed with tranquil weather.
Long term /Thursday through Monday/...
high pressure will be in control Thursday through Thursday night,
bringing dry conditions and above normal temperatures. There
could be a stray shower along the Mason-Dixon region Thursday
As high pressure moves over the western Atlantic, warmer
temperatures and increasing chances of showers and thunderstorms
will develop Friday through Sunday. The best chance for showers and
storms will be Saturday and Sunday.
A second area of high pressure will build into the region Monday,
bringing more seasonable temperatures and dry conditions.
Aviation /01z Tuesday through Saturday/...
VFR conditions next 72 hrs. Widely scattered or scattered
showers and T-storms are expected tomorrow. No restrictions are
anticipated. High pressure builds for Wed.
VFR conditions Thursday and Thursday night. Winds southwest 10 knots
Thursday and Thursday night. MVFR to IFR conditions are possible
with showers and storms Friday and Friday night. Winds southwest 5
to 10 knots Friday and Friday night.
srly winds expected to strengthen tonight with Small Craft Advisory conditions.
Winds will diminish toward morning. Very marginal Small Craft Advisory conditions
possible tomorrow, but not enough confidence to issue sca,
however, gusty winds in showers or T-storms may require mwss or
even smws due to very dry environment and potential for deep
Small craft advisories may be needed Thursday and Thursday night.
Winds southwest 10 to 15 knots gusts 20 knots. No marine hazards
expected Friday and Friday night. Winds southwest around 10
District of Columbia...none.
Marine...Small Craft Advisory until 2 am EDT Tuesday for anz531>533-
Small Craft Advisory until 4 am EDT Tuesday for anz534-537-543.