937
FXUS62 KILM 241344
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
944 AM EDT Wed Jul 24 2024

.SYNOPSIS...
Occasional showers and thunderstorms, some with heavy rain,
will continue through the remainder of the week as southerly
winds bring tropical moisture northward. A cold front could
move through the area Saturday, bringing unseasonably
comfortable temperatures and humidity in for early next week.

&&

.UPDATE...
A Flash Flood Watch remains in place across the far western CWA
through Thursday evening.

Airmass remains largely unchanged from last several days, with
PWAT over 2", and a moderate to strongly unstable airmass in
place. Not placing much stock in the accuracy of CAMs given
underwhelming performance as of late, however models continue to
signal the development of a swath of heavy rain inland late
this afternoon into the evening, potentially extending across
areas along and west of I-95. Showers and thunderstorms are
expected to become numerous inland this afternoon, with little
activity near the coast as the marine layer pushes inland.

&&

.NEAR TERM /THROUGH TONIGHT/...
Broad southwesterly flow continues on Wednesday with deep moisture
present across the central and eastern Carolinas. A similar forecast
as previous days. Morning convection likely to be near the coast and
may impact a few coastal communities. As the weak sea breeze
develops, isolated showers and storms should flourish and gradually
push westward through the afternoon. Outflows from the east and
initiation along the Piedmont trough should eventually lead to
scattered thunderstorms inland. Parallel flow aloft will again bring
the threat of heavy rain and localized flooding where training
storms develop. Clouds and precip will keep highs nearly the same as
yesterday: upper 80s along the coast and lower 90s inland.

Shower chances shift to the coast late tonight in persistent onshore
flow. Hard to pinpoint where the convergence band will be located
around and after midnight, but communities in extreme southeastern
North Carolina will have the best chance of a few isolated showers.
Overnight lows in the mid and upper 70s.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Our flow aloft will turn more westerly Thursday into Friday as a
shortwave moves from the Great Lakes across New England. This will
do little to stem the flow of mid level moisture as our source
region at 850 and 700 mb just shifts from the eastern Gulf to the
western Gulf. The surface flow should remain firmly from the south
around Bermuda High Pressure offshore. Like we`ve seen the past few
days, this should remain a very wet pattern with widespread showers
and thunderstorms expected. Precipitable water values in the 2.2 to
2.4 inch range, a deep warm cloud layer, and wind profiles favoring
convective lines and occasional backbuilding all mean heavy
rain and flooding will remain possible, particularly given the
increasing list of locations that have picked up 6+ inches of
rain over the past few days.

Coastal showers and thunderstorms are expected to start the day
Thursday. This activity will tend to redevelop inland during the
afternoon as the coast clears out behind the seabreeze front.
Showers and thunderstorms may continue area-wide Thursday night into
Friday as the veering flow aloft steers a stream of impulses across
the area. Forecast PoPs range from 60-90 percent each 12-hr period
Thursday through Friday with an additional 2-4 inches of rain
possible.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Saturday morning a cold front will advance southward and should move
through the eastern Carolinas. Convergence along the front and a
still moist and unstable airmass should maintain some risk for
showers and thunderstorms, particularly across South Carolina.
The mid levels will begin to dry out from north to south and
heavy rain will become less of a threat with time.

It`s difficult to imagine now, but a true airmass change appears to
occur this weekend. Surface dewpoints look like they will fall below
70 for what seems like the first time in forever. Mid level moisture
should diminish even more strongly and precipitable water values
could fall to near 1 inch, well below climatological norms for late
July. I`ve reduced forecast PoPs even lower than during last
night`s forecast and it looks like dry weather will occur Sunday
and Monday. Forecast lows Saturday night and Sunday night are
below 70 degrees away from the coast, leading to
uncharacteristically comfortable late July weather conditions.

By Tuesday, Bermuda High Pressure should become the dominant feature
on the weather map. Southeasterly winds should lead to increasing
dewpoints and deep layer moisture, and scattered showers and
t-storms may again become possible.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
Dissipating convection near the coast will push offshore as
southerly flow becomes re-established across the area. Patchy
MVFR possible along the coast this morning before the sea breeze
pushes inland during the early afternoon. A few isolated
showers or storms will be possible, primarily over southeastern
NC.

Another day of scattered convection likely inland. Scattered
storms begin to develop during the mid and late afternoon before
outflows prompt additional development. Have included the
potential for a persistent band of convection this evening
similar to previous days. Confidence is low that this will
directly impact the terminals, but there is potential for
IFR/LIFR in convection. Localized flooding from heavy rain is
possible. Low clouds possible thereafter.

Extended Outlook...Potential for IFR/MVFR with showers and
thunderstorms each day.

&&

.MARINE...
Through Tonight...South winds at 10-15 knots during the day weaken
slightly and become southwesterly overnight. Gusts up to 20 knots
during the day as a weak sea breeze develops. SE swell continues at
2-3 feet at 9 seconds. Convective minimum this afternoon should
precede the development of isolated to scattered storms tonight,
primarily after midnight.

Thursday through Sunday Night...Bermuda High Pressure offshore will
maintain a south-southwesterly wind across the Carolinas through
Friday night. The source region for this incoming airmass is the
northern Caribbean islands and the Bahamas, so plenty of moisture
will continue streaming across the area. Widespread showers and
thunderstorms are expected across the coastal waters Thursday
morning, diminishing in coverage Thursday afternoon and evening
as activity shifts inland. Activity should redevelop offshore
again late Thursday night leading to more widespread showers and
storms for Friday.

A cold front will approach from the north late Friday night into
Saturday morning, gradually bleeding drier air in from the
northeast. This should lead to dry weather Saturday night into
Sunday with no appreciable risk for showers and thunderstorms.

The primary wave group Thursday through Sunday should be the
southeasterly Bermuda swell averaging 2-3 feet every 9 seconds. On
top of this will be short period wind chop from southerly winds
Thursday, then from northeasterly winds Saturday night into Sunday.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Flood Watch from 2 PM EDT this afternoon through Thursday
     evening for NCZ087.
     Beach Hazards Statement until 8 PM EDT this evening for NCZ106-
     108.
SC...Flood Watch from 2 PM EDT this afternoon through Thursday
     evening for SCZ017-023-024-032.
     Beach Hazards Statement until 8 PM EDT this evening for SCZ054-
     056.
MARINE...None.

&&

$$

SYNOPSIS...TRA
UPDATE...CRM
NEAR TERM...21
SHORT TERM...TRA
LONG TERM...TRA
AVIATION...21
MARINE...TRA/21