Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 231450
Area Forecast Discussion
National Weather Service Wilmington NC
1050 AM EDT TUE AUG 23 2016
High pressure will extend along the East Coast through Thursday,
maintaining comfortable conditions. Upper ridge will expand
overhead late week and into the weekend bringing a return to
seasonable heat and humidity. Isolated showers and thunderstorms
may return this weekend.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --As of 1030 AM Tuesday...Quiet day on tap with surface high
centered north of the area and 5h ridge centered to the south. The
combination of moist low level northeast flow around the surface
high and strong capping around 7k ft may lead to a little more
cloud cover than would be expected, especially along the NC/SC
coast. Any diurnal cumulus that do develop will remain flat, tops
below 10k ft, with no chance of producing any rainfall. Clouds
quickly dissipate with loss of heating this evening. Only minimal
changes needed for morning update.
Previous discussion from 0630 follows: This morning`s landbreeze
front has pushed up to 10 miles off the coast. A few showers have
even developed off the Horry County SC coast. Radar cross-sections
reveal the reflectivity abruptly ends at 9000-10000 feet AGL, just
above where the strong subsidence inversion begins. Look for these
showers to fall apart later this morning as the landbreeze falls
500 mb high pressure centered over Florida will retrograde
slowly westward today. Massive subsidence in the vicinity of this
ridge continues to cover the Carolinas. In fact the scattered
clouds we have around the area this morning are mainly due to a
thin layer of moisture trapped beneath the subsidence inversion
around 7000 feet AGL. Surface high pressure centered over the Mid-
Atlantic states is feeding a stream of fairly cool, dry air
southward from Southeastern Canada. This airmass has obviously
modified a great deal from its passage across the warm western
Atlantic waters, but compared to the rest of the summer it`s a
Today`s highs should run a degree or two cooler than yesterday, 87-
91, mainly due to the airmass cooling in the continued NE flow.
However 850 mb temps of +14C to +15C are only about 1.5 degrees C
below normal. The surface high should edge off the Mid-Atlantic
coast tonight with NE winds continuing. Lows should range from 65-
70, warmest at the beaches.
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.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 300 AM Tuesday...The 500 mb ridge over the Gulf Coast on
Wednesday will move into western NC by late Thursday. Massive
subsidence aloft will continue to completely cap the airmass to deep
convection. At the surface, high pressure off the Mid-Atlantic coast
will move farther out to sea while extending a ridge axis
southwestward back into the Carolinas. This should maintain a
northeasterly low-level flow with little temperature change expected
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 300 AM Tuesday...Broad high pressure centered off the New
England coast will remain the dominant feature into next week as it
ridges weakly down into the Carolinas. While this occurs, expanding
mid-level ridge will amplify and encompass much of the Southeast,
leading to a return to above seasonable warmth and humidity while
keeping POP very low. 850mb temps climb back towards 20C, which when
combined with ample sunshine and easterly flow will bring a return
to heat index values a few degrees either side of 100 for the
extended. While this heat and humidity would support aftn
convection, significant subsidence beneath the ridge will suppress
all but the strongest updrafts, which by themselves will be
difficult to achieve due to weak lapse rates thanks to the warm mid-
level temps. Still, deep E/NE flow this wknd will bring PWATs back
to normal values for late August so will continue with very SCHC POP
for the latter half of the extended.
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
As of 12Z...High confidence for VFR through the valid TAF period
as high pressure continues to settle into the region.
Passing mid to high clouds this morning, few in nature, will
give way to nearly clear skies later this morning, and persist
through the remainder of the valid TAF period. Light
northeasterly winds this morning will become east-northeasterly
this afternoon, increasing to 5 to 10 kts before becoming light
and variable again tonight.
-- Changed Discussion --NEAR TERM /THROUGH TONIGHT/...
As of 1030 AM Tuesday...Surface high centered north of the area
will maintain northeast to east flow over the waters today and
tonight. A slow but steady increase in the gradient is expected
today and tonight in response to the tropical wave southeast of
the Bahamas moving ever closer. Solid 15 kt winds expected this
afternoon and overnight with seas running 3 ft.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 300 AM Tuesday...High pressure will move farther east off
the Mid- Atlantic coast through the period but will extend a ridge
axis southwestward across the Delmarva and into western North
Carolina. This should maintain a northeasterly wind across the
area with speeds 10-15 kt. Seas of 3-4 feet will subside Thursday
night as wind speeds diminish.
LONG TERM/FRIDAY THROUGH SATURDAY/...
As of 300 AM Tuesday...Broad high pressure will move offshore New
England but maintain a ridge axis down the coast into the upcoming
weekend. This will persist E/NE winds at 5-10 kts both Friday and
Saturday, with subtle shifts to SE at times. Seas will feature a low
amplitude E wind wave, but will be dominated by an amplifying SE 9
sec swell, creating wave heights of 2-3 ft, with some 4 fters
developing late in the period.
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As of 300 AM Tuesday...Wilmington has broken its record for the most
consecutive days with low temperatures of 70 degrees or warmer. It
remains to be seen if we make it down below 70 before sunrise,
potentially tacking on one more day to this record-breaking string.
Wilmington`s temperature records began in 1874.
Wilmington`s Consecutive Days with Low Temperatures 70+ degrees
#1 57 days 6/27/2016 to 8/22/2016
#2 56 days 6/29/2012 to 8/23/2012
#3 52 days 6/22/1941 to 8/12/1941
#4 48 days 7/ 6/1986 to 8/22/1986
#5 46 days 6/28/1991 to 8/12/1991
In Florence, SC the record for consecutive 70+ degree low
temperatures has also been broken. Florence temperature records
began in 1948.
Florence`s Consecutive Days with Low Temperatures 70+ degrees
#1 62 days 6/22/2016 to 8/22/2016
#2 60 days 6/26/2005 to 8/24/2005
#3 55 days 7/ 6/1975 to 8/29/1975
#4 46 days 7/10/2010 to 8/24/2010
#5 45 days 6/11/2015 to 7/25/2015
#5 45 days 6/28/1991 to 8/11/1991