Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
1124 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 /until 6 PM this evening/...
low pressure continues to move northeastward over the open waters
late this morning. Western edge of cloud shield is primarily north
and east of the Potomac River...and will continue to move
northeastward through this afternoon. Upslope clouds noted on
visible satellite over the Potomac Highlands. Will keep slight
chance probability of precipitation over this area for isolated shower potential through
this afternoon. Wind gusts will continue through the
afternoon...generally between 15-25 miles per hour...with occasional gusts to
30 miles per hour. 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 /6 PM this evening through 6 PM 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 /16z Thursday through Monday/...
primarily VFR this afternoon. Cloud deck will erode over
Washington District of Columbia late this morning...but persist over Baltimore metropolitan
for a few more hours. Potential for a period of MVFR at kmtn. 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.
Gale Warning over portions of Chesapeake Bay and lower tidal
Potomac has been converted to a Small Craft Advisory. Wind gusts
have been less than 30kt this morning...even under better late
morning mixing conditions. Small Craft Advisory is now in effect
for all waters. Gusts in the Lower Bay and tidal Potomac may reach
30 knots at times this afternoon. Models are also pointing to a
potential brief increase in gusts early this evening...so will
continue to monitor that possibility. 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 until 6 PM EDT Friday for anz532>534-537-