Scientific Forecaster Discussion
fxus61 kakq 181740
Area forecast discussion
National Weather Service Wakefield Virginia
140 PM EDT sun Aug 18 2019
a weak area of low pressure will track northeast along the
North Carolina Outer Banks and just off the southeast Virginia
coast this morning through this afternoon. Weak high pressure
builds into the area Monday and settles off the coast Tuesday.
Near term /until 6 PM this evening/...
as of 955 am EDT Sunday...
A weak area of low pressure is slowly tracking north-northeast along the
Outer Banks this morning bringing areas of rain and a few
embedded tstms to coastal NE NC. Otherwise, partly to mostly
sunny as morning fog is dissipating. Warm and humid with
temperatures in the mid 70s to around 80f and dewpoints in the
The system along the cntrl NC coast will lift newd along the NC
Outer Banks and just off the southeast Virginia coast this morning thru
early this aftn. Guidance is mixed with regard to how far north
showers will extend, but the latest short term/hi-res models
indicate the best chance for showers and perhaps a few embedded
tstms will push acrs coastal NE NC counties and far southeast Virginia this
morning into early aftn. Pops are highest (50-70%) along the
coast and adjacent to the Albemarle Sound and tapering off to
20-40% from the peninsula to the lower ern shore. There is a
potential for locally heavy rain, esply over coastal NE NC
counties, due to decent forcing for ascent combined with precipitable water
value upwards of 2.25" and a deep warm cloud layer.
Pops gradually diminish through this aftn, as the wave pulls
off the coast. The latest high-res guidance is showing less of a
potential for tstms drifting off the Blue Ridge later this
afternoon. However, there is a potential (~20%) for sea-breeze
convection of the lower Maryland ern shore this aftn. Continued humid
with high temps ranging from the lower/mid 80s along the coast,
with lower 90s from the I-95 corridor west where heat indices could
Short term /6 PM this evening through Tuesday/...
as of 415 am EDT Sunday...
Tonight through Tue will largely be dominated by mid and upper
level ridging and weak high pressure at the surface, as the
frontal boundary finally pushes well off the coast. Hot and
humid conditions develop as 850mb temps rise to 19-21c Mon and
Tue, and this should support high temps in the lower to mid 90s
(upper 80s at the coast) both days. Dewpoints potentially
remain 70-75f during peak heating resulting in heat indices of
100-105f. Morning lows will generally be 70-75f. Pops are mainly
20% or less Mon, and 15-30% Tue.
Long term /Tuesday night through Saturday/...
as of 350 PM Saturday...
Large scale pattern at the beginning of the extended period
will feature ridging over the wrn Atlantic/southwest US, with a
strong upper low just S of the Hudson Bay. Weak troughing over
the southeast US (between the two ridges) will allow for
isolated- scattered aftn/evening convection to develop on Wed
(pops mainly 20- 40%). Ridging over the wrn Atlantic slowly
retreats to the southeast on Thu/Fri. This happens as the area low low
pressure (sfc-aloft) over the Hudson Bay moves eastward and the
trailing cold front slowly approaches the region from the northwest. As
the cold front approaches the region by late Thu, more
organized convection could develop (especially north/west) late
Thu and persist through the first part of Thu night. As a
result, have high-end chc pops from 18z Thu-06z Fri. The cold
front potentially stalls over the srn part of the County Warning Area from Fri-
next weekend as the western Atlantic ridge tries to build back
westward. If the front stalls, this would lead to continued
chances of scattered showers/tstms (highest during the
Highs mainly in the low 90s on Wed-Thu, cooling into the mid
80s for most areas by Fri-Sat. Forecast lows are mainly in the
low 70s on Wed/Thu, with mid-upper 60s inland/around 70f near
the coast from Fri through next weekend.
Aviation /18z Sunday through Friday/...
as of 140 PM EDT Sunday...
Weak low pressure is pushing NE off the coast as of 18z. There
is very limited coverage of showers/tstms and this trend should
continue through the aftn. Hence, there is a very low
probability of a direct impact to a taf site and VFR conditions
are expected to prevail. The wind will shift from east/southeast this
evening to S/SW overnight as the low pulls well away from the
coast. Mostly clear conditions are expected tonight, with a low
probability of fog or stratus at sby. High pressure prevails off
the coast Monday, with a low probability (20% or less) of an
aftn/evening shower or tstm.
A trough will track across the area late Tuesday aftn into
Tuesday evening bringing a 20-40% chc of showers/tstms. The chc
for showers/tstms lessens Wednesday, and then increases Thursday
as a cold front approaches from the northwest. The potential for
showers/tstms could linger into Friday if the cold front slows
down or stalls over the region.
as of 345 am EDT Sunday...
Tricky forecast across the srn coastal waters today due to an area
of low pressure moving NE along the NC coast. Models show a variety
of solutions anything from winds less than 10 kts to Small Craft Advisory level winds
across the nrn ob. Thus, will increase the se winds a bit across the
srn coastal waters but keep them blo Small Craft Advisory levels. If Small Craft Advisory wind gusts
do occur, wind prob forecast suggests it would be a short term event
(2-4 hrs arnd 18z) before the winds turn back to the SSW behind the
departing low. Seas 2-3 ft except 3-4 ft across the south.
South-southwest winds aob 15 kt expected thru thurs. Waves 1-2 ft, seas 2-3