Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
116 am EDT Thursday Jul 31 2014
high pressure will slide off the coast for tonight into Thursday.
A frontal boundary will develop along the coast by Friday...then
move inland through the weekend.
Near term /until 6 am this morning/...
latest regional mosaic radar depicts only isolated showers over
central NC and over the central Appalachians...with the local area
precipitation free. Single light shower reached into southern Brunswick County
before dissipating this evening. Otherwise...skies have generally
cleared with temperatures falling into the upper 60s to low 70s.
Shortwave will dig into the Midwest overnight...with cirrus
streaming into the southern mid-Atlantic. Expect the cirrus shield to
remain south of the local area. Another shortwave rounds the base
of the upper low over the Great Lakes region...but remaining well
north of the region. Surface high pressure builds over the local
area...keeping the region precipitation free and generally clear to
mostly clear. Still rather comfortable night with lows in the
upper 50s to middle 60s. Upper 60s along the coast.
Short term /6 am this morning through Saturday/...
trough aloft will weaken/shift westward into the Ohio/TN/MS valleys
Thursday into Friday. Weak surface hi pressure will be off the CST Thursday...with south-southeast
low level flow across the area. A gradual increase in humidity is
expected...but still should be a dry day with warmer temperatures. Under
a partly or mostly sunny sky...highs will be in the middle to upper
During Friday...Bermuda hi pressure rebounds across the western Atlantic...with
deep layered southwesterly flow aloft (ovr the eastern seaboard) and a surface
frontal boundary developing along the southeast Virginia/NE NC CST. In
addition...an easterly surface flow from the Atlantic will provide increasing
low level moist. The combination of these features will result in
increased shower/thunderstorm chances...esply Friday aftn/eveng...and thus will
carry solid chance probability of precipitation (40-50%). With plenty of clouds around and
precipitation possible...hi temperatures on Friday will likely be a touch cooler than
Thursday...in the lower to middle 80s.
Friday night and Sat...the frontal boundary will nudge inland a bit
more...at least into eastern portions of the area. With a continued
moist surface-aloft flow over the region...and weak low pressure areas moving
north-northeast along the boundary...have gone with likely probability of precipitation (60%)
everywhere during this time. Expecting plenty of clouds...so highs
on Sat will be in the upper 70s to lower 80s. Lows Friday night ranging from
the middle 60s to lower 70s.
Long term /Saturday night through Wednesday/...
a stalled frontal boundary and associated plume of Atlantic moisture
will linger over the middle Atlantic Saturday night through Monday
between a strong ridge over the western Atlantic...and a trough over
the Midwest. Generally expecting mainly diurnal afternoon/evening
showers/thunderstorms Sunday and Monday...with lingering overnight/early
morning showers. A cold front drops through the Great Lakes Monday
night and Tuesday...and then into the Ohio Valley by midweek. This
will shove the plume of moisture offshore...with probability of precipitation gradually
diminishing to slight chance northwest-southeast by midweek. Highs should average in
the low/middle 80s Sunday/Monday...and trend upward to the middle/upper
80s Tuesday...and upper 80s to around 90 Wednesday. Low temperatures
should generally be in the upper 60s to low 70s.
Aviation /06z Thursday through Monday/...
high prssure moving off the middle Atlantic coast will continue the
VFR conditions through the forecast period. Expect only cirrus along
with scattered cumulus today. S-southeast winds at or below 10 kts.
Outlook...threat for showers/tstrms increase Friday & continue into
the weekend as moisture increases along a stalled coastal front.
weak high pressure will drift farther offshore tonight into Thursday
night. The wind should average 5-10kt out of the south-southeast. A
coastal/inverted trough develops along the southeast and middle
Atlantic coasts Friday and Saturday. The wind will become easterly
Friday...and shift to southeast by Saturday with speeds averaging at or below 15kt.
The trough pushes inland Sunday and Monday with the wind becoming
southerly and remaining at or below 15kt. Seas should average 2-3ft...with
1-2ft waves in the Bay.