Area Forecast Discussion
Issued by NWS Wilmington, NC-- Remove Highlighting --
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FXUS62 KILM 280524
Area Forecast Discussion
National Weather Service Wilmington NC
124 AM EDT THU JUL 28 2016
High pressure will expand across the Carolinas, maintaining
uncomfortable levels of heat and humidity this week. Isolated to
scattered showers and thunderstorms are possible each afternoon
and evening. The chances increase heading into early next week.
.NEAR TERM /THROUGH TODAY/...
As of 1210 AM Thursday...The convection to the north of southeast
North Carolina has moved off the coast and is no longer a threat
to the northeast portions of our forecast area. It will continue
to be muggy overnight with near 80s at the coast and the middle
70s well inland.
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
As of 3 PM Wednesday...Heat wave not only continues but appears
to peak in intensity on Thursday. Most areas well into the upper
90s and a few spots inland likely to hit 100. No relief from the
sea breeze save for south facing Brunswick County, as it will
remain pinned to the coast elsewhere. Solid Heat Advisory criteria
with dewpoint forecast now critical to who sees Heat Warning
criteria and for how long. Steeper hydrolapse rates are forecast
and thus some lower values may mix down to the surface. The
exception may be along the coastal counties where some slightly
higher dewpoints remain intact at the surface. A few spots could
hit a heat index of 110 but not for long enough or over enough
real estate to justify an Excessive Heat Watch at this time. An
upper impulse passes by on Friday leading to slight height falls.
This will slightly temper the heat and yield about 20 percent rain
chances over roughly the northern 2/3 of the CWA. Heat indices
will still be solidly in advisory criteria.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 3 PM Wednesday...Weak 5h troughing over the KY/TN valleys this
weekend will migrate off the coast for the middle of next week. The
resulting increase in moisture and mid level cooling will lead to an
increase in diurnal shower and thunderstorm coverage through the
period. The main surface features and convective triggers will
continue to be the Piedmont trough and the sea breeze with outflow
from the initial storms spawning others. Precipitable water values
will be at or above 2 inches through the period, which could lead to
periods of excessive rainfall. Late in the period the steering
pattern becomes rather anemic with storm motion dropping under 10
kt, so flooding could become an issue. Best precip chances look to
be Mon and Tue as the trough axis moves into the region. Precip
chances decrease slightly for Wed as the mid level trough axis moves
offshore and weak subsidence moves overhead. High temperatures a few
degrees above climo at the start of the period will trend toward
climo by the middle of next week. Low temperatures will run above to
well above climo.
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --As of 06Z...Once again a persistence forecast for the aviation
community. Mid level ridge will actually strengthen a bit through
the period with high confidence in VFR conditions. Some gustiness
expected once again today as well via deep mixing inland and the
sea breeze for the coastal terminals.
EXTENDED OUTLOOK...Isolated to scattered afternoon convection
through Sunday may create brief periods of MVFR/IFR. Otherwise
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 1210 AM Thursday...High pressure at the surface and aloft
will keep a southwesterly flow overnight. Seas will remain in the
2 to 4 ft range. Dominant wave periods shared between 3.5 seconds
and 6 seconds will make things a little bumpy.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 3 PM Wednesday...Not much will change on the surface weather
map through the period with high pressure remaining well offshore. A
low level jet will develop Thursday night and this could add a few
knots of wind to raise the forecast to 15 to 20kt. Some 4 ft seas
are progged to develop but they may remain just outside of the 20nm
zone border. These winds and seas may remain on Friday as though the
LLJ weakens a piedmont trough may drift a bit closer to the coast
increasing the gradient.
LONG TERM /SATURDAY THROUGH MONDAY/...
As of 3 PM Wednesday...Bermuda High will maintain southwest flow
over the waters with afternoon speed enhancement via the Piedmont
trough. Speeds will range from 10 kt in the morning to a solid 15
kt with higher gusts in the afternoon. Seas will run 2 to 4 ft.