Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Highlight Changed Discussion --
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FXUS62 KRAH 170826
Area Forecast Discussion
National Weather Service Raleigh NC
325 AM EST Fri Feb 17 2017
An upper level ridge over the Mississippi River valley will build
eastward over the Carolinas Friday into early Saturday. An upper
level trough will cross the region late Saturday through Sunday.
.NEAR TERM /THROUGH TONIGHT/...
As of 1020 PM Thursday...
A band of high based stratocumulus and altocumulus extended from
eastern Ohio SE across portions of north central NC late this
evening. Additional cloudiness was noted upstream headed SE. The
latest Hi-Res models show this band of moisture/cloudiness likely
will progress east and southeast overnight, spreading across the
region. The temperatures will be affected overnight. However, many
NE communities are already in the 20s. We will need to lower the
forecast temperatures for the NE and E into the 20s. These areas
that see an increase in clouds after midnight will also see the
temperatures stabilize or rise a few degrees. Otherwise, the latest
data/guidance which suggests minimal change to the previous
thinking. Lows 30-35 expected, with 20s NE of RDU.
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 115 PM Thursday...
Weak height rises will continue on Friday as a strong ridge
builds toward the eastern US, ahead of an upper low lifting out
of the southwest US. Other than some high clouds approaching
late Friday night, no sensible weather is expected, with a
warming southwest wind developing and guidance in good agreement
on upper 50s to mid 60s for high. Lows in the mid to upper 30s.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --As of 325 AM Friday...
Strong subsidence in the wake of the exiting trough will yield
abrupt west-east clearing by late morning/early afternoon Sunday
with a mild surface high building in from the west. Highs 70 to 75.
Lows in the 40s. The southern stream is forecast to remain active
with a vigorous Pacific upper trough/closed low forecast to move
slowly east across the southern Conus, with most recent runs of the
GFS and EC tracking the upper low across Mexico and into the Gulf of
Mexico during the mid week period. Such a solution/track this far
south will mean very little if any precip for central NC Wednesday
and Thursday, with bulk of rainfall staying across the Deep
South/Gulf Coast Region.
Instead, the main story will be the continuation of mild
temperatures underneath the amplifying downstream shortwave ridge
progged to move over the region through the mid week period. Expect
daytime highs a good 12 to 5 degrees above normal. Highs in the
upper 60s to mid 70s with lows in the 40s and 50s.
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.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 650 PM Thursday...
24 Hour TAF Period: VFR conditions are expected to continue through
the 24 hour TAF period, high confidence, as surface high pressure
slides across the Southeast U.S. This will allow northwesterly winds
this evening to become light and variable overnight, before becoming
southwesterly on Friday, with possibly some gusts of up to 20 mph.
Otherwise, we will see some mid and high clouds cross the area over
night, with mostly sunny skies expected by mid Friday morning
Outlook: Aside from a small potential for isolated showers assoc/w
an upper level disturbance crossing the area Sat night, VFR
conditions are expected to prevail through early next week.