Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 221133
Area Forecast Discussion
National Weather Service Wilmington NC
733 AM EDT MON AUG 22 2016
A cold front will move offshore early this morning bringing cooler
and much drier air into the region. High pressure behind this
front will extend down the East Coast through Thursday,
maintaining cool and dry weather. A return to seasonable warmth
and humidity, along with typical late summer thunderstorm chances,
will begin this weekend.
.NEAR TERM /THROUGH TONIGHT/...
As of 645 AM Monday...Dewpoints are falling as the cold front has
pushed off the coast. Forecast appears to be on-track and no
significant changes are needed. Discussion from 300 AM follows...
An outflow boundary from a convective cluster over the Outer
Banks Sunday evening pushed through SE North Carolina shortly
before midnight. Due to northwesterly winds behind this boundary,
the actual surface cold front is becoming difficult to find but
probably lies near the front edge of the tightest packing in the
surface dewpoint gradient from near New Bern to Fayetteville to
just south of Charlotte. The boundary should sweep cleanly through
the area by sunrise with northerly winds advecting drier air
southward throughout the day.
Weak cool advection behind the front should take our 850 mb temps
from +19c yesterday down to +16C to +17C today. Highs should reach
the upper 80s to around 90, but with dewpoints 10-15 degrees lower
than yesterday our heat indices shouldn`t be that much higher than
the actual air temperatures. Warm air above the frontal inversion in
the 6000-14000 foot layer should easily cap off surface-based
parcels, and no more than scattered flat cumulus and altocumulus are
850 mb temps should fall to around +15C tonight. With the
atmospheric column drying out so much (precip water down to 1.25
inches!) we should have fairly good radiational cooling. Lows should
fall to 64-68 inland with lower 70s at the beaches.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 300 AM Monday...High pressure aloft in the 700-500 mb layer
centered over Florida will retrograde along the Gulf Coast Tuesday,
then northward across Alabama into western Tennessee by late
Wednesday. Our atmosphere will remain quite dry and convectively
capped with near-zero PoPs forecast. High temps should range from
the upper 80s to around 90 with overnight lows in the mid to upper
60s inland and lower 70s near the beaches.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 300 AM Monday...Slightly cool and dry conditions persist
through the end of the week as high pressure centered over New
England gradually shifts east while maintaining its ridge axis down
the coast. Temps Thu will be slightly below climo for both highs and
lows, before warming back to seasonable norms on Friday. With PWATS
forecast to be just around 1-1.25 inches, mostly sunny conditions
without any chance of convection is forecast. During the wknd, the
surface high weakens locally but large mid-level ridging expands
across the Southeast. This will allow temps to recover to seasonable
norms or just above, along with increasing humidity and aftn chances
for convection. POP will remain below climo due to the suppressing
ridge aloft and lack of deep return flow, but at least SCHC will be
carried through the wknd as more typical late-summer weather
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --As of 12Z...Expect VFR through the valid TAF period as high
pressure builds into the area.
Latest observations indicate the cold front has moved offshore,
thus allowing for drier and cooler air to infiltrate into the
area. North-northeasterly winds this morning around 5 kts will
become easterly this afternoon, increasing to near 10 kts, with a
few passing mid to high clouds. Into tonight, quiet conditions
continue with winds become light and variable.
EXTENDED OUTLOOK...VFR expected.
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 645 AM Monday...The front is through and winds have shifted
to the north offshore and all the way south into the Charleston
area. Forecast appears to be on-track and no changes are needed.
Discussion from 300 AM follows...
A cold front will sweep southward and across the coastal waters
early this morning, clearing the area by sunrise. Northerly winds
behind the front will persist today, veering northeasterly tonight
as the surface high over the Midwest moves into the Mid-Atlantic
states. After an initial surge this morning wind speeds should die
down to 10 knots or less this afternoon. This should actually be
light enough to allow a weak seabreeze to develop at the beaches.
Seas currently 2-4 feet, highest near and just east of Cape Fear,
should diminish to only 1-2 feet this afternoon. Increasing NE wind
should then build seas by about a foot late tonight.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 300 AM Monday...High pressure over the Mid-Atlantic states
will move off the East Coast Tuesday afternoon, but should continue
to extend a ridge axis southwestward across the Mid-Atlantic region
through Wednesday and Wednesday night.
Falling atmospheric pressures across the Bahamas and within the
vicinity of what may be the remnant circulation of Tropical
Depression Fiona east of 70 degrees longitude will help tighten up
the pressure gradient along the southern periphery of the ridge. Our
surface winds should increase to NE 15 knots with occasional 20 knot
gusts Tuesday through Wednesday, with seas building to 3-4 feet.
LONG TERM/THURSDAY THROUGH FRIDAY/...
As of 300 AM Monday...High pressure will extend down the coast
Thursday before weakening and shifting offshore during Friday. This
creates winds shifting slowly from NE at 10-15 kts Thursday, to E/SE
at 5-10 kts during Friday. Seas of 3-4 ft will be common Thursday,
with the exception being the typical much smaller seas of 1-2 ft in
the wave shadowed region SW of Brunswick County. On Friday, as the
SE winds develop but speeds weaken, wave heights will become a more
uniform 2 ft throughout the coastal waters.
As of 300 AM Monday...Wilmington has now tied its all-time record
for consecutive days with low temperatures of 70 degrees or warmer
established back in 2012. We should make it through midnight tonight
remaining above 70 degrees which means we`ll break this record by at
least one day. Our forecast low Tuesday morning is 69 degrees which,
if correct, would end the string of consecutive days at 57.
Wilmington temperature records began in 1874.
Wilmington`s Consecutive Days with Low Temperatures 70+ degrees
#1 56 days 6/29/2012 to 8/23/2012
#1 56 days 6/27/2016 to 8/21/2016 <--still going!
#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