Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
813 am EDT Sat Apr 25 2015
high pressure over Maine will move offshore today. Low pressure
over Missouri will track to our south tonight into Sunday. An
upper-level trough of low pressure over Maine will track slowly
south Monday. High pressure will return Tuesday. Low pressure may
impact the region Thursday.
Near term /until 6 PM this evening/...
8am update...getting a few more reports of snow across northern Maryland
along Mason Dixon line from media/mping. Not sure if it will actually
measure...but extended chances for mix r-/S- through 14z.
Have also dropped all freeze warning and frost advisories that
remained for NE portion of the County Warning Area.
..rest of previous afd follows...
Today...rain spreads north into the area ahead of a warm front.
Categorical probability of precipitation begin midday for far southwestern zones and 90/100 probability of precipitation
spread NE across the District of Columbia metropolitan area through the evening. The front
stalls over southern Virginia and Baltimore looks to be on the northern
fringe of the precipitation shield.
Short term /6 PM this evening through 6 PM Sunday/...
tonight...stationary front returns south as a cold front after
midnight. Precipitation shifts south along with it...with likelies limited
to the southern third of the County Warning Area for Sunday morning. Storm total quantitative precipitation forecast
quarter to half inch for southern two thirds of County Warning Area...tenth inch or so
for northestern Maryland. Min temperatures low to middle 40s.
Sunday...north winds and somewhat clearing skies from north to south
through the day. Just low chance probability of precipitation for southern zones for the
afternoon. With a little drier forecast...raised maximum temperatures to low
60s for much of the area...a degree above mav/met/gmos blend.
Long term /Sunday night through Friday/...
average high temperatures in late Mar are a70...lows m40s. In the extend 70 is
probably the best we can hope for...and lows should be right around
Have incrsd the cloud cover cwa-wide/introduced rain shower into the forecast Monday
for the northern/eastern part of County Warning Area. Vertically stacked low will be spinning
in the Gulf of ME...and a sharpening trough will work its way southward down
the east CST into the middle altc Monday. Below normal highs expeceted - gnrly in
the u50s...possibly m60s in the central shen vlly.
Weak induced high over the area Tuesday/Wednesday will allow for more sunshine
and temperatures to rebound back into m60s. An area of low pressure is expeceted
to develop over the Gulf states Thursday...causing incrsg clouds in the middle
Atlantic along west/ a chance of rain. This low is expeceted to track NE and
combine west/ a short WV descending from Quebec...forming another Gulf
of ME low. This one is expeceted to form too far out to sea to have any
impact on the middle Atlantic outside of keeping the area in cool nearly
The week should close out under high pressure.
Aviation /12z Saturday through Wednesday/...
VFR through midday as ceilings lower and rain spreads in from the south
ahead of a warm front lifting north from NC. Front stalls over the
area tonight before shifting south as a cold front Sunday morning.
Best chances for rain for District of Columbia metros this evening into late tonight.
IFR ceilings develop along the frontal zone tonight. North winds around
10 knots Sunday.
Rain shower/potential MVFR ceilings possible Monday...then no probs expeceted Tue/Wed.
north winds from high building from the north are channeling down
the Bay. Gusts generally around 15 knots...though occasional 20 knots
cannot be ruled out through sunrise. Will issue marine weather
statements as necessary as this surge moves through. Light and
variable flow today as high pressure moves over the area and a warm
front enters from the south. Front stalls tonight with north winds
Sunday as the front returns south as a cold front. Northerly
channeling will need to be watched for Sunday afternoon.
Small Craft Advisory conds will be likely Monday aftr a cold fnt moves through the waters and
the pressure gradient tightens.
District of Columbia...none.