Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
504 PM EDT Monday Mar 10 2014
a weak trough will slide across the area and off the coast
tonight. Otherwise...high pressure will drift from the Gulf Coast
states eastward to off the southeast coast tonight through
Tuesday. Low pressure approaches the middle Atlantic region Tuesday
night. An associated warm front becomes located across northern
Virginia by Wednesday morning...with the trailing cold front
crossing the region late Wednesday afternoon through Wednesday
evening. Canadian high pressure builds into and over the area
Thursday and Thursday night.
Near term /until 6 am Tuesday morning/...
a weak trough was moving into and across the region this
afternoon...producing plenty of middle level clouds over northern/NE cnties and
even a few light showers. Otherwise...where there was more
sunshine...temperatures were climbing into the 60s to near 70. That trough
will slide east-southeast and off the CST tonight. So...there may be a light
shower over the Virginia eastern shr into early this eveng. Otherwise...mostly
clear to partly cloudy tonight with lows in the lower to middle 40s.
Short term /6 am Tuesday morning through Thursday/...
above normal high temperatures expected Tuesday and Wednesday...then much
colder/below normal readings for Thursday. A very nice day in store for
the region on Tuesday...under a partly to mostly sunny sky. West-southwest surface
winds 5 to 10 miles per hour will help temperatures climb into the middle 60s to the
Increasing and thickening cloudiness Tuesday night...as low pressure tracks
from Missouri east-northeast into northern Kentucky/southern Ohio. Isolated showers may move into
extreme western cnties toward Wednesday morng. Lows Tuesday night in the middle 40s to lower
That low will intensify as it continues NE to just off the New
England CST Wednesday into Wednesday night. Went more with a blend of the 12z
NAM and 12z European model (ecmwf) for precipitation timing moving into and across the region.
Will have highest probability of precipitation from later Wednesday morng into early Wednesday
eveng...and maintained a slight chance of thunder in the grids Wednesday afternoon
into Wednesday eveng...as models still indicating marginal instability
(per lifted indice's 0 to -2) right in advance of the cold front. Cold front
pushes off the CST/out to sea Wednesday eveng/ngt...with precipitation ending from
west to east late Wednesday afternoon into Wednesday eveng. Rainfall amts of around .25
inch expected at this time...with locally higher amts possible in
any heavier showers or strong thunderstorms. Stronger south-southwest winds ahead of
the cold front will help temperatures climb into the middle 60s to lower 70s
most places on Wednesday.
Much drier and colder airmass then filters into the region Wednesday night
and Thursday. Mostly clear to partly cloudy Wednesday night with lows ranging
from the middle 20s to middle 30s. Partly to mostly sunny on Thursday with highs
only in the lower to middle 40s.
Long term /Thursday night through Monday/...
cold start to the extended forecast Friday morning as strong northwest flow
and cold air advection will continue behind the low pressure system
moving off the coast. Do not expect a prolonged period of cold temperatures
as high pressure that builds in from the west quickly moves east and
a return flow results helping to push a warmer airmass back into the
Flow remains out of the SW on Sat as models indicate convergence
along a surface trough may produce a line of light showers on Sat.
High pressure to the north begins to nose down into the middle-Atlantic
Sat night ahead of the next approaching surface low that will be
forming in the southeast US and moving NE on Monday. Chances for
precipitation increase Sun night into Monday with the approach of
that low pressure system.
Expect temperatures in the middle 50s for Friday...rising into the low 60s for
the weekend. Cold morning temperatures in the 20s expected for Friday with
upper 30s for lows prognosticated through the weekend.
Aviation /21z Monday through Saturday/...
VFR conds expected through the taf period. Noting some middle/high
clouds across northern terminals (kric/ksby). These will quickly
diminish by late afternoon/evening, with a clear sky expected
Outlook: surface low pressure tracks from the Tennessee Valley through the
northern middle-Atlantic late Tuesday/Wednesday before shifting off the coast
late Wednesday. Expect MVFR conds (brief periods of ifr) with rain showers
possible, especially at kric/ksby. VFR conditions return by early
Thursday with gusty northwest winds.
weak surface trough moves across the waters overnight with a brief
increase in winds but due to the cold water...mixing will be very
limited and winds will stay below Small Craft Advisory criteria.
Conditions over the waters remain benign through Wednesday morning. At
this time a strengthening low pressure system moving into the Ohio
River valley will help to increase the pressure gradient over the
mid-Atlantic. Strengthening SW winds will occur on Wednesday but
again...do to the warm airmass moving over the colder
waters...mixing of the strongest winds to the waters surface will be
difficult. With that said...small craft conditions will be likely
ahead of the system Wednesday afternoon into Wednesday evening. At this point the
system and associated cold front will have made its way across the
waters and significant pressure rises and cold air advection will
take place. These factors will set the stage for a fairly confident
Expect waves to increase over the Bay from 3 feet on Wednesday afternoon to
around 5 feet by Thursday morning as the strong northwest winds move in. Seas
approaching 8 feet at 20 nm out will be possible by Thursday afternoon...with 3
to 5 feet seas likely closer to shore. Conditions relax by Thursday night
as high pressure begins to make its way into the area.