Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
703 am EDT Tuesday Jul 7 2015
high pressure will be centered off the southeast coast this
afternoon through Thursday. Meanwhile...a frontal boundary will
approach from the north and west...stalling just north of the area
Wednesday night through Thursday afternoon. This will result in
hotter temperatures with the best chance for showers and
thunderstorms late Wednesday afternoon into Wednesday night. That
front will then drop down across the region Thursday night into
Near term /until 6 PM this evening/...
the pattern finally looks to be drier today...as weak ridging
aloft develops along/off the southeast and middle Atlantic coast and low level
flow turns more to the south-southwest. Along with rising 850 mb temperatures and
increasing amts of sunshine...expect more typical summertime heat
with hi temperatures into the lower 90s most areas. Hi temperatures at the
immediate CST will be in the 80s. Will maintain a 20% pop in the
middle/late afternoon/early evening period for scntrl/southeast Virginia and NE
NC...even though forcing is weak.
Short term /6 PM this evening through Thursday/...
warm/humid tonight with lows in the lower to middle 70s. Wednesday is still
expected to be rain-free into the middle afternoon...before a frontal boundary
from the northwest drifts closer...combining with heating...could result
in late afternoon/eveng thunderstorms...esply across the northern 1/2 of the County Warning Area.
Probability of precipitation will range from 20% across extreme southern Virginia and NE NC...to 40-50%
across north-northeast counties. Highs will range from the upper 80s to middle
90s...with heat indices 95 to around 100. Models show some continued
shortwave energy overnight Wednesday night across the NE zones...and will
maintain chance probability of precipitation (30%) there into the early morng hours of Thursday.
Lows 70-75. Continued hot on Thursday with highs in the upper 80s to middle
90s. Slight chance of late afternoon/eveng thunderstorms across northern portions of the
Long term /Thursday night through Monday/...
southeastern U.S. 500 mb ridge will gradually build west into the Southern
Plains this weekend. This will allow northwest flow to develop over the middle-
Atlantic region by late week into the weekend...with a series of
disturbances diving south. Timing of these features will be
difficult...so mainly went with typical diurnal thunderstorm probability of precipitation of 20-30%
each afternoon/evening through the weekend. Seasonable temperatures are expected
through the period with lows in the upper 60s to middle 70s...and highs
in the upper 80s to low 90s...except low/middle 80s at the beaches.
Aviation /12z Tuesday through Saturday/...
as of 702 am EDT...VFR conditions across area terminals this
morning, with mainly VFR conditions expected to persist through
the day. Atmosphere will remain well mixed this evening with sharpening
through of low pressure inland...and have therefore kept winds in
taf at or above 5kt overnight tonight with some occasional gusts to ~15
knots through the overnight at orf/phf. A typical Summer pattern
expected for the middle to late week period, as a weak cool front
will again approach the area, only to stall just north of the
local area. Typical isolated late afternoon/evening thunderstorms possible Wednesday-
Thu, clearing overnight. Outside of convection, mainly VFR
conditions expected. However, will also need to watch for more of
the same late night/early morning low clouds/visible restrictions for
the middle to late week period.
as of 702 am EDT...typical summertime pattern setting up for the
middle to late week period. Surface high will longer over the western
Atlantic as weak surface trough sharpens inland. SW flow has developed
over the waters this morning...and will persist through Thursday
west/ speeds generally at or below 15 knots. Wavewatch in general agreement with
going forecast, and have made minimal changes there. Seas avgg 2-4
feet/Bay 2-3ft tonight through Thursday.