Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
345 am EDT Thursday Oct 23 2014
Low pressure east of the Delaware-Maryland-Virginia will slowly track east of Long
Island today. High pressure will return to the middle Atlantic tonight and
remain over the area into the first part of next week.
Near term /today/...
Aftr the cloudy/rainy weather of the past 2 days today will be a day of
transition...which looks to be leading into some very nice weather this weekend.
Vertically stacked low pressure presently 330 miles east of District of Columbia continues to
spin light rain into New Jersey/Delaware but this has been diminishing as it tracks
southward towards Maryland. What is left as it moves into the northestern part of
our forecast area is low clouds. This will likely continue in the balt area for
much of the daylgt hours.
The pressure difference between the low and high building into Ohio/in will
result in a brzy day across the area. Nwrly winds will help to keep
temperatures down today. Warmest area should be the central shen vlly.
Highs should range from the m60s near cho to the u50s along the M-d
line and in The Highlands.
Time of partial eclipse - 5:50 to 6;15 PM. Approx 1/4 of sun will be
covered in the southwestern sky. Clouds should be diminishing during this
time. Best chances for viewing will most likely be in the western part of the
County Warning Area and central shen vlly.
Short term /tonight through Friday/...
High pressure continues to build into the area tonight. Clouds should be
diminishing during the evening. Winds should decouple overnight. Temperatures
ranging from the m30s in The Highlands to the u40s in the cities.
Majority of the area should drop into the lm40s.
Friday should be the beginning of several very nice days. High pressure building
over the area should lead to M sunny skies...lighter nwrly winds.
High temperatures in the mu60s outside of The Highlands.
Long term /Friday night through Wednesday/...
While the influence of the upper closed low continues to drift away
from the New England coast late Friday...another embedded upper trough
will pass overhead into early Sat. This feature will be dry...only
bringing some scattered batches of low-middle cloud decks over the
area. An strong upper jet will then carry the next clipper-feature
down from the western Great Lakes into eastern portions of New England from
Sat into sun. Guidance members in the good agreement about this next
wave and the lack of precipitation expected to affect our area.
All the while...high pressure will continue to hang across the deep
south and cover much of the East Coast. This will keep moderated and
near-average conditions for our region to close out the week and
continue into early next week. The main difference in the forecast
over the medium range will be Sunday...W/ the appearance of the back
end of the upper trough will make a subsidence swipe across the
region and mix-down some of gusty winds.
Much of the associated rain west/ this feature will occur well to our
north and/or dissipate across portions of western/central PA before
reaching the Mason-Dixon line both Sat and sun. Probability of precipitation were kept out
of the area for the near term and not introduced again until the end
of the forecast period west/ an expected cold frontal passage. The
southeast high pressure zone will roll across the Carolinas and off
the coast early next week...pushed along by another low pressure
system building across the plains. Still uncertainty in the long
term model depiction of this feature's progression and whether it
will break off into separate waves of weaken and lift off to the
northeast before making much of an impact on the East Coast. Leaned
toward the Euro west/ the southern stream piece splitting off and eventually
sliding a weakening and precipitation-light cold front over the area
Aviation /06z Thursday through Monday/...
Low pressure spins off the middle altc CST. This will slowly track north-northeast today
but continues to push Atlantic moisture into the northestern part of the forecast
area. This is keeping BWI/mountain ceilings at or below 030..and this should continue
for several more hours b4 rising into VFR range. Rmdr of taf sites
should be VFR today. Winds will continue to be gusty from the northwest.
VFR conds at all taf sites tonight and Friday.
A breezy afternoon on sun but not overly so...mainly a steady 15-25kt northwest
breeze during the daytime hours - dissipating overnight. High pressure
will keep the area's weather quiet otherwise. The next weather-feature
expected to be a cold frontal passage toward the middle of next week.
Winds gusting into the mu20 knots level on much of the waters at this time.
Pressure gradient will continue across the middle Atlantic today. West/ further low level
destabilization aftr sunrise Gale Warning is in effect on ches Bay S
of Sandy pt. Winds should be diminishing this evening...but only to
Small Craft Advisory levels. Small Craft Advisory should continue Friday.
High pressure will largely build over the area and keep a quiet-weather
influence for much of the upcoming week. Although...a fast-moving
upper wave will carry gusty winds on sun aftn/eve...Small Craft Advisory conds
expected during this time...but no other hazardous conditions
anticipated into early next week.
District of Columbia...none.
Marine...Small Craft Advisory until midnight EDT tonight for anz530-531-
Small Craft Advisory from 9 am to 6 PM EDT Friday for anz530-
Small Craft Advisory from 6 PM this evening to 6 PM EDT Friday
Gale Warning until 6 PM EDT this evening for anz532>534-537-