Area Forecast Discussion
Issued by NWS Blacksburg, VA-- Remove Highlighting --
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FXUS61 KRNK 221615
Area Forecast Discussion
National Weather Service Blacksburg VA
1215 PM EDT SUN MAY 22 2016
A series of low pressure systems will lift northeast off the mid
Atlantic and New England coasts through Tuesday as higher
pressure builds slowly east from out of the Mississippi Valley.
.NEAR TERM /THROUGH TONIGHT/...
As of 1020 AM EDT Sunday...
Expect to see showers break out more as we head toward
midday/early afternoon. The high-res models are favoring a
corridor from the Alleghanys into Southside VA for better coverage
while a nw flow increasing into the region will keep some rain
shadow aspects over the NC foothills with lack of forcing. Still
seeing drier air aloft on the 12z sounding mainly above 700mb.
Still with cool pool moving in from the northwest will see shallow
convection. Instability is marginal but cannot rule out some
thunder. Forecast temps are on track so no changes to the previous
Previous valid discussion...
Several spokes of short wave energy rounding base of upper trof
over the central and northern Appalachians will help to amplify
upper flow and support development of vertically stacked H7-H5 low
pressure that will drift south from out of upstate NY into eastern
VA by this evening - then drift east to the coast by daybreak
Shower threat continuing until at least mid- to late evening
until thermodynamic support wanes.
Cool air advection and cloud cover in most areas should help to
keep daytime highs lower than those experienced on Saturday -
mainly mid 50s across the highest elevations, to around 70 across
southside VA into north central NC. Overnight lows should be
fairly uniform across the area - mainly mid to upper 40s in the
mountains, to the lower 50s across the Piedmont.
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
As of 320 PM EDT Saturday...
The blocky upper pattern which has been prominent for the past several
days will slowly be transitioning through the first part of next week.
The closed upper low and associated cold pool aloft over the mid
Atlantic region will be replaced by a broad low amplitude upper ridge
and a Bermuda high at the surface by the middle of the week. This will
bring a gradual improvement in our weather along with a significant
The influence of the upper low combined with diurnal instability will
still be great enough to keep a good chance of showers across most of
the region on Monday. By Tuesday as the ridging begins we will be down
to just a slight chance of showers across the eastern portion of the
area. However as the evolution of the pattern begins to pump steadily
warmer and more moist air into the region the chances for showers and
thunderstorms will start to increase again by Wednesday afternoon.
We will start the week with very cool conditions as temperatures remain
5 to 10 degrees below normal with highs in the lower 70s east of the
Blue Ridge and in the low to mid 60s to the west. However by Wednesday
we will be getting a taste of summer with highs in the middle 80s east
of the Ridge and in the mid 70s/around 80 to the west.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --AS OF 1211 PM EDT Sunday...
Expect warmer...more like mid to late June type temperatures and
weather from midweek into the holiday weekend as an upper ridge
builds over the Southeast U.S. This pattern will favor mainly dry
yet more humid conditions. There will be enough instability and
moisture each day across the Appalachians to generate scattered
showers and thunderstorm, with less threat in the Piedmont. The
cycle will be typical diurnal afternoon/evening variety.
Highs Thu-Sun will range from the upper 70s to lower 80s in the
mountains to mid to upper 80s in the piedmont.
Lows will generally run from the upper 50s to lower 60s mountains to
mid 60s piedmont.
-- End Changed Discussion --
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
As of 735 AM EDT Sunday...
Onset of daytime heating will allow ceilings and visibility to
gradually improve back to VFR in most areas by mid-late morning.
By afternoon, sufficient heating expected for sufficient vertical
cloud development to support scattered showers, with most
activity along and north of a line extending from KBLF to KDAN.
Localized flight restrictions back into MVFR range, with some
localized IFR restrictions in heavier showers, are possible.
However, most areas outside of shower activity should experience
mainly a broken ceiling in 4-6K foot AGL range.
Surface gusts of 20 to 30 knots can be expected across the higher
elevations during time of best surface heating today - with 10-20
knot gusts possible east of the Blue Ridge.
Scattered showers expected to wane, and eventually end over the
entire terminal forecast area tonight following loss of daytime
heating. However, some isolated lingering showers/sprinkles may
occur until after midnight along and east of a KLYH-KDAN line
which will remain closer to an upper level low pressure system
near the coast.
On Monday, winds will start to decrease as the center of the
upper low slowly exits the region. Isolated showers with periodic
sub-VFR conditions will still be possible during time of best
daytime heating. However, by Monday night, and continuing into
Wednesday, expect mainly VFR conditions to persist as high
pressure settles into and over the area.
On Thursday, we should start to see some potential for shower and
thunderstorms to pop up during the heating of the day - mainly in
the mountains. Late night/early morning fog with associated flight
restrictions into the MVFR or IFR range may start to become an
issue by midweek, most notably in the climatologically favored
areas such as at/near KLWB and KBCB.