Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
721 am EDT Friday Oct 9 2015
high pressure to the south of the area moves offshore this
afternoon. Meanwhile...a cold front will approach from the
northwest today...then drop through the region this evening into
Saturday morning. Low pressure will develop along or just off the
southeast coast by Sunday and linger into Monday.
Near term /until 6 PM this evening/...
hi pressure to the S of the area early this morng...will move offshr
this afternoon. Meanwhile...a cold front which was pushing through Indiana
and Illinois early this morng...will slide east-southeast and move into northwest
portions of the region by early this eveng. Increasing SW surface
winds in advance of the front combined with a partly sunny
sky...will result in a rather warm day across the area. Chance for
showers/isolated thunder will arrive into northern/northwest counties late this
afternoon/early this eveng. Highs in the upper 70s to lower 80s.
Short term /6 PM this evening through Sunday/...
latest GFS and European model (ecmwf) remain in general agreement with the cold
front pushing through the region this eveng into Sat morng. Will
maintain hi chance to likely probability of precipitation (50-60%) across much of the area.
Lows tonight will range from the upper 50s northwest/north to the middle 60s southeast.
Sat through sun...going with a blend of the latest GFS/European model (ecmwf) models
which are in close agreemen with regard to developing low pressure just
off the southeast CST. As an upper low/trough digs south-southeast into the southeast states on
Sat...it will force the best precipitation chances S into southern/southeast Virginia and NE NC
during the day. Otherwise...decreasing chances for precipitation from north-northwest to
south-southeast...with gradual improvement in sky cover also. Cool cad setup
on Sat will keep maximum temperatures in check...as highs will range through
Slight to small chance probability of precipitation will linger over extreme southeast Virginia and NE NC Sat night
into sun morng...as upper low closes off near the SC CST. Mainly dry
conditions then expected everywhere on sun...as deeper moisture
shifts farther south-southeast of NE NC. Partly to mostly sunny across much of
the region on sun. Lows Sat night ranging from the middle 40s to middle 50s.
Highs on sun in the upper 60s to lower 70s.
Long term /Sunday night through Thursday/...
the period begins Sun night with an anomalous cutoff/upper low
centered along or just off the SC/Georgia coast gradually filling and
weakening into an upper level wave off the southeast coast into Monday
night. Latest 12z runs of the GFS/European model (ecmwf) are in better agreement
with this scenario...though some subtle differences in placement
an timing still persist. Will maintain low chance probability of precipitation over the
far southeast zones Sat night through Monday although bulk of support for
precipitation stays south and east of the local area. Highs Monday generally in
the 70-75 f range. Another cold front pushes through the area on
Tuesday...followed by a stronger area of high pressure building in by
Wednesday...and becoming centered south of the area on Thursday. Will carry
just 20% probability of precipitation across the area with the front on Tuesday...then
dry/mostly sunny Wed-Thu. Highs will be seasonable in the 70s with
lows generally ranging from the upper 40s northwest to middle-upper 50s southeast
through the period.
Aviation /11z Friday through Tuesday/...
predominate VFR conditions continue to prevail across area
terminals this morning...with the exception of ecg and vicinity,
where some shallow ground fog is bringing some diminished visibilities.
Scattered-broken middle to high clouds should be enough to limit fog
development most locales early this morning. Weak high pressure
slips off the coast early today with return flow from the south
increasing...and becoming breezy with the onset of diurnal mixing
later this morning (sw wind gusts to ~20 knots at all terminals lt
morning through aftn). Timing of precipitation expected to hold off until
after 22z at sby, and after 00z at remainder of area terminals.
Outlook...a cold front approaches tonight and moves across the
region overnight/early Saturday. Showers are expected
overnight...continuing into Saturday over korf/kecg as the front
slows its progress off the coast. High pressure and favorable
aviation conditions should prevail Sunday through Tuesday.
latest observation reflect south-southwest flow 10-15 knots over the waters this morning.
1020+mb surface high pressure, now oriented just offshore of the East
Coast this morning. Pressure gradient will continue to gradually
tighten today as a cold front approaches from the northwest today.
Pressure falls still don't look very impressive...but winds will
remain south-southwest today...increasing to around 15kt Bay and
rivers...15-20kt across the ocean. Could see some gusts to 20kt across
the Bay. However...given that the waters have cooled off recently,
would expect predominate conditions to be sub- Small Craft Advisory...and thus have
capped winds at 15 knots today. Have gone with Small Craft Advisory for ches Bay and
northern/central coastal zones concurrent with period of Post-frontal
surge late tonight and Sat. Winds turn around to the north-northeast and
increase to 15-25 knots Sat...persisting into early Sunday across the
Lower Bay and southern Virginia/NC coastal waters. Given forecast
timing, have held off with headline for now over far southern
waters, which will likely experience Small Craft Advisory conditions late in 3rd
forecast period (sat) or early Sat night. If current forecast
trends hold, brief period of Small Craft Advisory will need to be extended into
Sunday for the Lower Bay and southern coastal zones.
Continued to follow a blend of the 09/00z European model (ecmwf)/gefs for late in the
weekend into early next week. Expect a gradual return to predominant
sub-Small Craft Advisory conditions to the area for Sun afternoon/Monday through Monday
night. Cool surface high pressure across the northeast
/mid- Atlantic regions, while surface low pressure develops along the front
just off the NC/SC coast, sliding NE offshore Monday through Monday
night. Winds veer to the south-southwest Tuesday ahead of a second, stronger
cold front. That front crosses the waters later Tuesday, with
another area of cool high pressure building east from the Tennessee/Ohio River
Marine...Small Craft Advisory from midnight tonight to 6 PM EDT
Saturday for anz630>632-634-650-652-654-656.