Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
505 PM EDT Monday Mar 17 2014
low pressure off the middle Atlantic coast...will track east northeast
out to sea tonight. A second area of low pressure will move from
Florida northeast off the southeast and middle Atlantic coasts later
tonight through Tuesday. A cold front will approach from the west
during Wednesday...then swing across the area Wednesday night. High
pressure will build into the region Thursday.
Near term /until 6 am Tuesday morning/...
have issued a Winter Weather Advisory for portions of central/scntrl
Virginia...interior southeast Virginia...and Northampton County NC for tonight until 11
am Tuesday morng. Radar indicated area of precipitation moving through southern half of
the County Warning Area late this afternoon...with a mixture of snow...sleet and
possibly freezing rain/drizzle occurring in these locations. Temperatures
were between 30 and 32 degrees also. Areas of precipitation should remain
across southern third of Virginia into NE NC tonight into Tuesday morng...as another
low pressure system moves from Florida NE to off the southeast CST. Expect any
snow in the advisory area to change to a mixture of light freezing
rain/drizzle mixed with some sleet this eveng...and last through Tuesday
morng...as temperatures will stay nearly steady or drop a degree or two.
Lower chances farther north-northwest for snow flurries or some sleet...but not
enough moist/quantitative precipitation forecast to cause any other problems. Mainly just rain for
extreme southeast Virginia and NE NC. Min temperatures ranging from the middle 20s northwest to middle
Short term /6 am Tuesday morning through Thursday/...
the second low will move from off the southeast CST to well off the middle Atlantic
CST Tuesday into Tuesday eveng. Precipitation over eastern/southeastern portions of the region
Tuesday morng...will gradually shift east-southeast and offshr during the day.
Expect a mostly cloudy or cloudy sky with maximum temperatures only ranging
from the upper 30s northwest to the upper 40s southeast.
Generally dry Tuesday night...as weak upper ridge builds over the area. Light NE
flow will maintain a mostly cloudy or cloudy sky. Min temperatures will
range from the lower 30s to lower 40s. A cold front will approach from the
west during Wednesday...then moves through the area Wednesday eveng/Wednesday night. Still
generally mostly cloudy or cloudy on Wednesday...but winds will shift to
the southeast or S helping to boost temperatures into the 50s. Partly to mostly
sunny and milder on Thursday...as hi pressure builds in from the west. Maximum temperatures
will range from the middle 50s to lower 60s.
Long term /Thursday night through Monday/...
a blocking pattern with ridging near the West Coast will maintain
troughing over the NE Continental U.S.. although mild weather will end the
week...Arctic high pressure over western Canada will sweep another
cold air mass across the eastern part of the nation and bring
another round of below normal temperatures early next week.
GFS/Euro 80h temperatures drop to around 10 degrees below zero
celsius Monday. Stuck close to wpc temperatures but if low level
temperatures are as cold as indicated...these may need to be
lowered a bit with later forecasts. No precipitation is expected except for
a chance of showers with the cold front Saturday.
High temperatures Friday and Saturday are expected to be from the
upper 50s to around 60 on the lower Eastern Shore to the middle and
upper 60s over inland southern Virginia. Highs on Sunday cool to
the 40s at the coast and the middle and middle 50s inland. Highs on
Monday will range from the lower 40s to around 50. Lows in the 30s
Friday morning and then 40s Saturday lower back to the 30s Sunday
and middle 20s to lower 30s Monday morning.
Aviation /21z Monday through Saturday/...
low pressure off the North Carolina coast moves to the northeast.
Another low develops Tuesday east of Georgia. High pressure ridge
will ridge from New England southwest into central Virginia and
interior portions of the Carolinas...developing into a wedge
pattern. A very moist airmass will low clouds over the area.
Conditions at each of the taf sites have varied between MVFR and
IFR and see no reason for that to change. With that in mind...kept
IFR in the forecast through the next 24 hours except at sby. At
sby...both MOS forecast have conditions improving to MVFR during
the day Tuesday as a bit drier air moves in.
Light mixed precipitation will taper off tonight. Due to fog and intermittent
precipitation...kept visibilities from 2 to 4 miles. More precipitation is expected at orf
and ecg on Tuesday morning under the influence of the second low
North to northeast winds will prevail will not be as gusty as they
were early this morning.
Outlook...conditions improve Wednesday ahead of a cold front...
which could bring a few showers. Dry conditions will prevail
Thursday and Friday. More showers are possible Saturday.
subtle amplification of a high pressure ridge in the middle
Atlantic and a digging upper level trough in southern Louisiana will
slow the departure of the coastal low this evening. Meanwhile...
another surface low moves north along the southeast coast tonight into
Tuesday morning. Persistent N-NE/onshore winds will remain between
20-30 knots for Bay/sound/ocean tonight...keeping seas elevated to
8-12 feet across coastal waters through this evening. The rivers
will remain at or below 15 knots. One exception will be the mouth of the
James River which will be 15-20 knots with occasional gusts up to
25 knots through midnight... followed by a brief lull in winds at or below
15 knots overnight. A new Small Craft Advisory has been issued for the mouth of the
James River beginning now through Tuesday evening (see next
paragraph for more information).
The low moves up the NC coast Tuesday morning...then off the NC
Outer Banks during the afternoon which will result in a tightening
pressure gradient through the day (primarily south of Parramore
Island as the low deepens). There will be a brief surge in north-NE
winds during the day and speeds should range from 20-33 knots
Ocean/Bay/sound/mouth of the James River. The rest of the rivers
may reach speeds of 15-20 knots...but would like to see how winds
unfold Tuesday morning before issuing a Small Craft Advisory for these areas. The
potential exists for gale force gusts of 35 knots to be reached
during Tuesday afternoon...but like the rivers...would like to see
upstream wind observation gusting to gales before issuing this type of
headline. Winds finally diminish at or below 15 knots late Tuesday evening.
Small Craft Advisory conditions on the ocean will persist through at least
Wednesday evening as onshore flow persists...taking seas longer to
subside. Seas could stay around 4-6 feet through Thursday before
finally dropping below 5 feet.
coastal flood statements remain intact through this evening for
the Maryland lower Eastern Shore. Strong NE winds and a near full moon
will result in elevated water level through this evening. Low
lying Atlantic basins near Ocean City may experience nuisance
flooding during high tide this evening even with water levels
staying at least 0.5 feet or less below minor flooding thresholds.
At Ocean City...high tide this evening occurs at 904 PM.
record low maximum temperatures for 3/17:
Ric...40 in 1900
orf...38 in 1893
sby...33 in 1916
Maryland...Winter Weather Advisory until 5 PM EDT this afternoon for
High surf advisory until midnight EDT tonight for mdz025.
NC...Winter Weather Advisory until 11 am EDT Tuesday for ncz012.
High surf advisory until midnight EDT tonight for ncz102.
Virginia...Winter Weather Advisory until 11 am EDT Tuesday for vaz087>089-
Winter Weather Advisory until 5 PM EDT this afternoon for
High surf advisory until midnight EDT tonight for vaz095-
Winter Weather Advisory until 11 am EDT Tuesday for vaz060-
Marine...Small Craft Advisory until 8 PM EDT Wednesday for anz650-652-
Small Craft Advisory until 11 PM EDT Tuesday for anz630>632-
Small Craft Advisory until 8 PM EDT Tuesday for anz633-638.