Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Remove Highlighting --
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FXUS62 KRAH 190032
Area Forecast Discussion
National Weather Service Raleigh NC
731 PM EST Sat Feb 18 2017
An upper level trough will approach from the west today and cross
the southeastern U.S. tonight through early Sunday. High pressure
will build into our region behind the exiting low pressure system
Sunday night and Monday.
.NEAR TERM /THROUGH TONIGHT/...
As of 240 PM Saturday...
Still looks like a very minimal precip event for central NC into
this evening. The mid level ridge axis over eastern NC will continue
to shift ENE and offshore through tonight, as the mid level low now
near Memphis fills and deamplifies a bit as it tracks to the E then
ESE into the Carolinas overnight. Both moisture and forcing for
ascent out ahead of this low are rooted in the mid and upper levels,
including a band of decent upper divergence, mid level DPVA, and mid
level height falls of 50-70 m, acting on a band of enhanced elevated
moisture aloft noted on water vapor imagery now streaming through SC
and western NC. But lift in the low levels is negligible, with
fairly dry air below 700 mb, so the precip band now running from KY
through SW NC and W SC/E GA will have a tough time generating
measurable precip at the ground as it progresses to the NE. Have
made minor tweaks to earlier update, retaining low chance pops (for
measurable light rain) over the SW CWA for a few hours late this
afternoon into early evening, trending to just scattered sprinkles
elsewhere for a few hours during the evening as this precip band
translates to the NE, with much of the precip evaporating before it
hits the ground. Skies will continue trending W to E to mostly cloudy
this evening, then trending back to partly cloudy overnight as the
dry slot now pushing into W GA shifts over our area. Expect mild
lows mostly in the low-mid 40s tonight, with expectations of
rebounding dewpoints as the mid level low shifts into the area,
preceded by passage of a weak surface trough through the area. -GIH
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 245 PM Saturday...
Quiet weather with very few clouds and warm temps. A light surface
flow from the NW will persist Sun as high pressure builds in from
the west. We`ll likely see a few clouds in the morning as a
vorticity lobe dives into the base of the shortwave trough over the
area. But as this trough pushes ESE and offshore, rising heights and
warming aloft will bring generally clear skies. Thicknesses should
remain well above normal, similar to today`s readings, indicating
highs from around 70 to the lower 70s. Lows once again mostly in the
lower to mid 40s Sun night under clear skies. -GIH
.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 315 PM Saturday...
The forecast for the long term will be characterized by temperatures
well above normal for the middle to late part of February. Monday
begins with a very strong upper level ridge over the area and high
pressure at the surface leading to mostly clear skies and
temperatures into the 70s. This will continue through Tuesday but
with increasing clouds as a frontal system approaches.
Wednesday a dry frontal passage occurs but temperatures stay warm
with return flow around high pressure in the western Atlantic. This
will keep high temps in the 70s for the remainder of the work week.
Uncertainty with the timing of a system next weekend could mean
either a wet Saturday and a dry Sunday or vice versa. Either way our
next chance for some decent rainfall will be next weekend. Stay
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --As of 730 PM Saturday...
24 Hour TAF Period: VFR conditions are expected to continue through
the 24 hour TAF period, high confidence. An upper level disturbance
will move across central NC this evening into early Sunday morning.
However, with such a dry low level airmass in place ahead of the
disturbance only very light rain and/or sprinkles along with cigs of
6 kft or above area expected with the system. Skies will begin to
quickly scatter/clear off behind the disturbance, with mostly sunny
skies expected for Sunday. Sporadic southwesterly wind gusts of up
to 20 mph will be possible will be ahead of the system as well. High
pressure will build into the area on Sunday, with winds out of the
west-northwest to northwest, with possibly some gusts to 20 mph.
Outlook: VFR conditions will dominate through at least Mon evening.
Model differences then crop up regarding a passing mid level trough
through the region, reducing confidence, but there is at least a
chance of sub-VFR conditions late Mon night/Tue morning, and again
late Tue night/Wed morning and Wed night/Thu morning as we get into
moist SW flow.
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