Area Forecast Discussion
Issued by NWS Wilmington, NC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KILM 280142
AFDILM

Area Forecast Discussion...cor
National Weather Service Wilmington NC
934 PM EDT WED JUL 27 2016

.SYNOPSIS...
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 TONIGHT/...
As of 934 PM Wednesday...Massive storm complex and continuous
lightning ravaging `Downeast` Carteret county this hour with
plentiful low-level heat and dripping dewpoints to tap. Upper ridge
holding firm here and no action so far. Southbound outflows seems
partially thwarted by the moderate SW synoptic wind flow, so no
mentionable pops remains planned. A `Heat Advisory` at a minimum
will be needed tomorrow, but will await full 0z data suite as it is
not out of the realm that warnings may be needed. Balmy but a fair
night to prevail right into first light of Thursday.
The previous forecast discussion follows.

As of 624 PM Wednesday...One of a hand-full of days when asphalt
layers and roofers hope for rain, as blistering maximum apparent
temperatures seared the landscape. Even the normally cooling sea
breeze played cruel tricks today, only boosting heat indices as
dewpoints bumped upward despite a fall in air temperature through
it`s passage. `Feel-like` temps will fall through the lower 100s
and 90s well into evening, and min temperatures may not drop below
80 across numerous coastal and coastal interior locations. The
longest streak of 80 degree or higher minimums at ILM is 3 and
this ended on Augusts 5th 1980. This consecutive record string
will probably not be broken as guidance suggest upper 70s the next
several days but something to watch through sweated brows. Will
maintain the pop free forecast overnight as the upper ridge in
vapor movies can be seen pumping in a feed of more heat aloft.
This hour both the air and water temperature at Frying Pan shoals
buoy were matching at 85, so a grillout on the boat would
represent cool outdoor dining if compared to a backyard right now.

&&

.SHORT TERM /THURSDAY NIGHT 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 /02Z THURSDAY THROUGH MONDAY/...
As of 00Z...Surface high pressure off the southeast CONUS will
combine with a weak trough over the mid-atlantic to produce
southwesterly flow across the area through 00Z Friday. Do not
expect convection to develop due to the effects of upper ridging,
as well as limited moisture from 700-400 mb.

EXTENDED OUTLOOK...Isolated to scattered afternoon convection
through Sunday may create brief periods of MVFR/IFR. Otherwise
expect VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 934 PM Wednesday...High pressure at the surface and aloft
will keep a southwesterly flow through the period. A few knots of
wind may be added to the forecast as a weak low level jet
develops. Seas will remain in the 2 to 3 ft range. Dominant wave
periods shared between 3.5 seconds and 6 seconds will make things
a little bumpy. TSTMS possible south of Cape Lookout.

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.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
NEAR TERM...Colby
SHORT TERM...Bacon
LONG TERM...III
AVIATION...CRM
MARINE...Bacon/Colby/REK


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.