Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
659 am EDT Sat Oct 25 2014
high pressure will drift off the coast today...ahead of a dry cold
front...which will drop across the area tonight through early
Sunday. High pressure builds back over the area late Sunday through
the middle of next week.
Near term /through tonight/...
latest weather analysis features 1020+mb surface high pressure over the
west-central Gulf Coast/Tennessee Valley. To the north, a quick moving
area of low pressure continues to push across Ontario/northern
Great Lakes, with the associated surface cool front now extending SW
into the upper Midwest and middle Missouri Valley.
A pleasant fall afternoon on the way today as surface high pressure nudges into
the region from the southwest...eventually shifting offshore
tonight. Model cross sections indicate a dry vertical column along
with a west-northwest downsloping flow. This should allow for plenty of
sunshine today with seasonably mild highs in the upper 60s to low
Dry cold front pushes into the area late tonight into Sunday
morning, with little more than some scattered clouds with the frontal passage.
Breezy and a bit milder tonight with lows generally middle to upper
Short term /Sunday through Tuesday/...
low pressure over southeast Canada will drop across New England early
Sunday, before pushing northeast into Atlantic Canada by Sunday
night. Meanwhile, high pressure will continue to build east from
the Ohio/Tennessee Valley...shunting surface front south into the Carolinas
Sunday afternoon. High pressure builds over the area Sunday night and
Monday, before shifting offshore Tuesday. Expect ample sunshine
each day. Downslope wind will help to boost highs between 70-75 both
days. Lows Sun night mainly in the 40s except u30s western most areas to
l50s southeastern beach areas. Highs Monday in the low to middle 70s, with
highs in the upper 70s to around 80 on Tuesday after lows mainly
in the 50s early Tuesday morning.
One additional note...well mixed atmosphere and compressed pressure
gradient will result in a breezy day on Sunday. This along with relative humidity
falling <30% will result in conditions that approach critical
thresholds. See fire weather section below for more details.
Long term /Tuesday night through Friday/...
mild/warm to start in extended then trending cooler by the end. Hi
pressure surface-aloft remains in vicinity of southeast and mdatlc csts Monday night through Tuesday
before shifting east allowing broad trough (aloft) to settle from the
Great Lakes to the eastern states. Cold front will approach from the west-northwest
Wednesday...then push across the forecast area Wednesday night into Thursday afternoon. West/ the fnt...expecting
periods of cloudiness and (right now) a low chance pop (for shras). Ahead of the
fnt...mild/warm southwesterly flow and skc-pcldy...then vrb clouds from lt Wednesday
into Friday as air turns cooler (on return of north-northwest wnds).
Hi temperatures Tuesday ranging through the 70s (maybe l80s over interior
sections)...then l/m70s Wednesday...and mainly in the 60s Thu/Fri. Low temperatures
in the 50s in the l/m50s Monday night...M/u50s Tuesday night...l/m50s Wednesday
night...then m40s to l50s Thursday night.
Aviation /12z Saturday through Wednesday/...
high pressure falls apart as it crosses the area today. Expect VFR
conditions and light SW winds to prevail with the exception of
some patchy ground fog this morning. Fog will lift/dissipate
shortly after 25/1200z. A weak trough passes through the region
this evening and will bring scattered clouds of 7-10 kft through
the area roughly between 25/2100z northwest through 26/0600z southeast. A weak but
dry cold front will then cross the region late tonight into Sunday
morning...mainly veering winds to the northwest and becoming breezy
during the day on Sunday. Gusts will average 15-20kt inland with
higher gusts around 30kt along the immediate coast.
High pressure settles over the middle Atlantic region Sunday night
and Monday...then slides off the coast Monday night through
Wednesday. Conditions will continue to be dry/VFR with winds
becoming south at generally less than 15kt. The next cold front to
impact the region is expected to cross the area Wednesday night.
Expect breezy southwest winds to develop with increasing cloud
cover as Wednesday progresses.
a brief diurnal surge in northwest-north winds (10-15kt) is occurring as of 4am
and should persist through at least 7-8am this morning.
Otherwise...high pressure falls apart as it crosses the waters
today. Northwest winds this morning will back to the west by this afternoon with
speeds at or below 15kt all waters. Seas/waves will average 2-4ft/2-3ft
respectively. A weak trough passage will occur this evening...
followed by a weak cold frontal passage late tonight into Sun
morning. West winds at or below 15kt will persist through the evening and
then veer to the northwest behind the cold front. Speeds will increase to
due to low level cold air advection (10-15kt rivers/sound...15-20kt
with gusts to 25kt ches Bay...15-25kt with gusts to 30kt coastal
waters Fenwick Island to Virginia/NC border). Seas will be slow to rise
due to a west-northwest direction but should average 3-4ft from 10-20nm. Up to
5ft seas will be possible near 20nm from Fenwick Island to
Chincoteague. Small Craft Advisory flags have been raised for ches Bay and coastal
waters from Fenwick Island to the Virginia/NC border beginning after
midnight tonight and persisting through Sunday. Please refer to
mwwakq for exact timing. High pressure settles over the waters on
Monday and then slides eastward off the coast Monday night through
will be highlighting dry conditions in the fire weather forecast.
Mixed layer deep temperatures prognosticated into the l-m30s by 18z Sunday will
yield relative humidity values ~30%. This in tandem with gusty northwest winds between
15-25 miles per hour and dry fuels after dry frontal passage. If present forecast
thinking verifies, an enhanced Fire Danger Statement may be
needed if the 10 hour fuel moistures drop below 10%.
Marine...Small Craft Advisory from 6 am to 6 PM EDT Sunday for anz632-
Small Craft Advisory from 2 am to 6 PM EDT Sunday for anz630-
Small Craft Advisory from 2 am to 11 PM EDT Sunday for anz650-