Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
154 am EDT Tuesday Apr 28 2015
a weak trough of low pressure will push through the region this
evening...with high pressure building back in from the west later
tonight through Tuesday. The high will slide off the coast on
Wednesday...with the next low pressure system tracking along the
southeast coast Wednesday night through Thursday.
Near term /until 6 am this morning/...
current analysis continues to show surface high pressure over the
upper Midwest and surface low pressure off the Canadian Maritimes.
Strong upper low aloft centered off the coast of Maine...but
extending well to the south and west to the lower Great Lakes. WV
satellite reveals a significant shortwave diving southeast across the middle
Atlantic and central Appalachians. Cloud cover is beginning to
dissipate this evening although some locations remain mostly
cloudy. However...all areas should become mostly clear after
midnight. A few very isolated sprinkles may linger through
midnight...but should dissipate thereafter. Lows tonight should
mainly be 40-45f...a few upper 30s are possible over interior
Virginia...to the upper 40s/around 50 f immediate southeast Virginia/NE NC coast.
Short term /6 am this morning through Thursday/...
short wave will be sheared out/south-southeast of the region on Tuesday...should see
mostly sunny skies with less afternoon cumulus development than Monday. Highs
will get a little warmer...though remain about 5 degree below
average...middle 60s near the coast to upper 60s/around 70 f well
inland. Surface hi pressure then weakens/drift off the CST into Wednesday. Low
pressure exiting scntrl Continental U.S. Tuesday/Tuesday night begins to track through the
Gulf CST states on Wednesday...bringing gradual increases in cloudiness/moisture
into the middle Atlantic region. Models continue to hold off most of any significant
precipitation until lt Wednesday. Will maintain 30-50% probability of precipitation Wednesday afternoon SW...dry
NE. Hi temperatures Wednesday from the m60s SW to upper 60s/lower 70s elsewhere.
Deeper moisture pushes in from south-southwest to north-northeast Wednesday night...with both
the GFS/European model (ecmwf) bringing what looks to be a good overrunning event
later Wednesday night/Thursday morning to at least the southern 1/2 of the County Warning Area.
Bumped probability of precipitation up to likely south...high chance north later Wednesday night.
Lows mainly from the upper 40s to lower 50s. Strong upper low now
prognosticated to drop south from the Great Lakes to the southeast states on
Thursday...as surface low intensifies off the NC coast. Better agreement
between GFS/European model (ecmwf) warrants likely probability of precipitation most areas Thursday...although
not necessarily going to rain all day as track of upper low will
make uncertainty fairly high as to quantitative precipitation forecast amounts. Cooler/mainly
cloudy with highs in the upper 50s to Lower-Middle 60s.
Long term /Thursday night through Monday/...
the upper low traverses the Carolinas Thursday night
then pushes well out to sea by late Friday. Showers linger across
the entire area Thursday night...then primarily over eastern areas
Friday morning/midday...before finally ending late Friday afternoon or evening.
Will carry likely probability of precipitation (60%) most areas Thursday night...then solid
chance probability of precipitation (30-40%) on Friday. Dry weather then returns Friday night into
early next week as surface high pressure prevails and an 500 mb ridge builds
over the southeast. Lows generally in the 40s to low 50s Thursday/Friday
nights...warming into middle/upper 50s by next sun/Monday nights. Highs
Friday from the low 60s Eastern Shore to the upper 60s far SW zones.
High temperatures warm by next weekend into the 70s...with low 80s possible
inland next Monday.
Aviation /06z Tuesday through Saturday/...
VFR conditions will persist through the upcoming taf period. High
pressure will ridge into the region from the Midwest Tuesday.
Drier air over the area should keep the sky mostly clear.
Outlook...high pressure will continue to dominate the weather into
Wednesday with dry and VFR conditions to persist through at least
Wednesday evening. A slow moving area of low pressure developing
along the Carolina coast will bring a chance of rain beginning
Thursday morning with a likelihood of sub-VFR conditions and the
chance for some rain rain showers over southern Virginia and NC. Rain and MVFR/local
periods of IFR are forecast Thursday night before ending on Friday.
low pressure over New England will bring an increase in
wind speeds to the local area by this evening and lasting through Tuesday
morning. Sca's remain in place for all waters during this time.
Waves will build to 3-4 feet on the Bay tonight...with seas building
to 4-5 feet on the ocean. Conditions improve Tuesday afternoon through Wednesday night.
Another round of Small Craft Advisory conditions is likely for all waters Thursday/Friday as
low pressure moves up the coast.
Marine...Small Craft Advisory until 10 am EDT this morning for
Small Craft Advisory until 1 PM EDT this afternoon for