Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
916 am EDT Monday Oct 20 2014
high pressure will move offshore this afternoon. Low pressure will
enter the region from the northwest tonight...persisting over the
middle-Atlantic coast into Thursday. High pressure will return for
the end of the workweek and into the weekend.
Near term /through tonight/...
temperatures have moderated into the upper 30s and low 40s at 9am...so
frost/freeze headlines were allowed to expire.
High pressure resides over eastern Virginia/MD/NC this morning. Cirrus
deck has moved into northern and western Maryland...western Virginia and WV...and will
affect most of the forecast area today. A well mixed atmosphere
today with southerly/southwesterly flow gusting up to 20 miles per hour this afternoon.
925mb temperatures around 12c...maximum temperatures middle to upper 60s.
Short term /Tuesday/...
a cold front associated with the Great Lakes low will cross the area
tonight. Moisture returns ahead of the front...with widely scattered
and light showers ahead progress across the area through the night.
The upper low approaches Tuesday with mainly westerly flow. The downslope
will counteract the height falls. Therefore...went with scattered
coverage for probability of precipitation through the day. Maximum temperatures lower than Monday northwest of
District of Columbia from cloud cover. Could it 70f southeast from District of Columbia should the clouds hold
off long enough.
Long term /Tuesday night through Sunday/...
the 1st part of the extend will be controlled by the closed/vertically
stacked low pressure area. Much of the rmdr will be influenced by a
return to high pressure.
Tuesday night and Wednesday should be cloudy. "Showery" may be the best word to
describe this period. Not rainy...just periods of rain west/ rlvtly low quantitative precipitation forecast.
Temperature-wise not much of a diurnal variation - lows in the u40s/highs
in the mu50s.
The low is expeceted to slowly drift towards southern New England...W/ high
pressure working its way back into the region on nwrly winds. Brzy/
blustery might be good words to describe Thursday as the higher pressure
builds into the middle Atlantic. Highs ranging from the u40s in The
Highlands to the l60s near the ches Bay. Majority of the area
should have highs in the 50s.
Aftr that a slow warming trend should take place under M sunny
daytime skies leading into the weekend. High temperatures for the upcoming
weekend expeceted to be in the m60s over most of the area. Lows in the 40s.
Aviation /13z Monday through Friday/...
VFR continues through today as the high shifts offshore with return
southerly/southwesterly flow gusting up to 18 knots this afternoon. Weak cold frontal
passage tonight with scattered showers. Low pressure approaches from
the northwest Tuesday with downsloping westerly flow limiting rain
coverage to scattered.
Tuesday night/Wednesday expeceted to be cloudy. Heights will probably in the "low VFR
range"...possibly descending into MVFR. Skies should imprv Thursday and Friday.
return flow today as high pressure moves off shore. Small Craft Advisory late this
afternoon into the evening for Maryland Bay south of Pooles Island for southerly
channeling up to 20 knots. Weak cold front late tonight shifts winds
west. Westerly flow Tuesday as low pressure approaches from the northwest.
Small Craft Advisory conds expeceted Wednesday night and Thursday...possibly continue into Friday.
District of Columbia...none.
Marine...Small Craft Advisory from 3 PM this afternoon to 8 PM EDT this
evening for anz531>533-540-541.
Small Craft Advisory from 3 PM this afternoon to 2 am EDT
Tuesday for anz534-537-543.
Near term update...kcs