Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
157 am EDT Sat Aug 29 2015
high pressure will reside over the region through the weekend and
into next week.
Near term /through today/...
very quiet weather as high pressure....centered over the Middle-
Atlantic States late this evening...is providing dry and
seasonable weather. This area of high pressure will slowly drift
into the western Atlantic by Saturday evening...but will continue
to provide quiet weather. Conditions should be good again
overnight for radiational cooling. Based on last night...have
stayed under guidance for lows with readings again reaching the upper
50s to lower 60s away from the coast.
The models show some high level clouds trying to slide over the
area on Saturday so have bumped up the sky cover a bit...but
expect that this cirrus will be pretty thin so should still see
lots of sun. For highs generally went near to or just a degree
above todays highs...which is close to the guidance.
Short term /tonight through Monday/...
the area of high pressure slowly loses its grip on the regions
weather on Sunday...but the front that is stall off the southeast coast
does not get much of a push to come back north and slowly
dissipates. However...the models do show an upper low pressure
system over the lower Mississippi Valley lifting northeast and
into the area late Sunday into Monday. This feature may be enough
to generate some showers...mainly across southeast portions of the County Warning Area
were the moisture is more plentiful.
For Saturday night...continues the trend of the dry weather with
lots of clear sky. But with some cirrus around...stayed close to
the MOS guidance as cooling conditions will not be as good as the
last few nights. On Sunday...kept the weather dry but with the
flow beginning to turn more southerly...should see humidity begin
to increase with highs getting back into the upper 80s to near 90
With the upper low beginning to approach Sunday night into
Monday...should see the clouds thicken a little and the chance for
an isolated shower will increase...especially on Monday. For now
have held the chances to the southeast of the path of the shortwave...but
if the moisture is a little more abundant could see showers reach
all the way back to the I-85 corridor. For temperatures...should
see a milder night Sunday night ... held temperatures down a
few degrees from sundays highs on Monday with readings more middle to
Long term /Monday night through Friday/...
the longwave pattern next week is expected to be characterized by
broad middle/upper ridging from the north-central to northestern US...with a weak
trough in vicinity of the Gulf Coast. Broad east-southeast flow beneath the
ridge is expected to bring increasing tropical moisture into the
southeastern US. The bulk of this moisture is expected to be from ts
Erika...or its remnants at that time. The general model consensus
shows the middle-level anticyclone centered from the Ohio Valley to middle-
Atlantic through at least Wednesday...which should keep moisture
suppressed S of the region. Given this...forecast probability of precipitation will be below
15%. Beyond that there is more uncertainty. If the middle-level high
center retreats far enough north some of this moisture could spread into
the area later in the week. However...if the high remains overhead
moisture should remain S of the region. 20-30% probability of precipitation have been
introduced mainly into Friday to account for this uncertainty. Warm
and increasingly humid through the week with forecast highs in the
upper 80s to low 90s Tuesday/Wednesday...with middle 80s at the
immediate coast. By Thursday/Friday forecast highs drop into the
middle/upper 80s...with low 80s at the beaches. Forecast lows are in
the upper 60s to low 70s.
Aviation /06z Saturday through Wednesday/...
high pressure and VFR conditions prevail across the local area
early this morning. Surface winds calm to light...at or below 5 knots. Do not
anticipate any more than shallow ground fog as dry conditions
High pressure remains over the region today...resulting in dry
conditions and scattered afternoon cumulus with decks 4-6k feet above ground level. Winds
generally S to southeast at or below 10 knots.
Outlook...mainly dry and VFR conds with winds at or below 10 knots will
continue through the middle of next week. There will be a threat
for patchy shallow ground fog each morning near sunrise.
high pressure is centered over the northern middle-Atlantic this
afternoon...with weak low pressure well off the southeast coast.
This is producing a north-NE wind across the area...with speeds of 5-
10kt (10-15kt S of the Virginia/NC border). The high is expected to drop
into the region tonight and then slide offshore Saturday. The wind
gradually shifts to east-southeast by Saturday afternoon (although NE will
likely persist S of the Virginia/NC border) with speeds remaining at or below 10-
15kt. Similar conditions are expected to continue into
Sunday...before the flow gradually becomes southerly early next
week...with wind speeds no higher than 10-15kt. Seas remain elevated
at 3-4ft off the Currituck Outer Banks tonight into Saturday.
Otherwise...seas should average 2-3ft...with 1-2 feet waves.