Garner, North Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

999
FXUS62 KRAH 201138
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
738 AM EDT Mon Apr 20 2026

.WHAT HAS CHANGED...

* A Frost Advisory has been issued for roughly the northern half of
  central NC for Tue morning, after patchy to areas of frost result
  in the usual cold spots this morning.

&&

.KEY MESSAGES...
As of 330 AM Monday...

1) Patchy to areas of frost will result in the usual cold spots this
morning, then again for much of the Piedmont and nrn Coastal Plain
Tue morning.

2) Weather parameters will be supportive of Increased Fire Danger
today, with brief Red Flag conditions possible over the northern
Piedmont and northern Coastal Plain.

3) Temperatures will be above normal through the extended forecast
period. Generally dry through the end of the work week, with the
next chance of rain over the weekend.

&&

.DISCUSSION...
As of 330 AM Monday...

KEY MESSAGE 1... Patchy to areas of frost will result in the usual
cold spots this morning, then again for much of the Piedmont and nrn
Coastal Plain Tue morning.

Downslope drying over the Piedmont, of a Pacific airmass and 1026 mb
surface high centered over the Deep South and Southeast, has
combined with calm within the ridge to support excellent radiational
cooling this morning. Indeed, temperatures in the usual cold spots
over the Piedmont are already supportive of frost at this hour.

A reinforcing, polar cold front, now stretching across the nrn
Middle Atlantic and lwr OH Valley, will progress swd and across cntl
NC late this afternoon through evening - a few hours slower than
previously forecast. The slower frontal progression and passage will
yield delayed CAA and decoupling potential, as the center of a
following, 1027 mb cP high over the upr MS Valley settles over VA at
around 1030 mb by 12Z Tue. A blend of statistical guidance, favored
in radiational cooling regimes, has trended slightly less chilly in
recent days but still well below the warm-biased NBM in such
regimes. Nonetheless, a few hours of decoupling and calm to very
light nely stirring nearest the center of the high over VA (ie. over
the nrn half of cntl NC) will likely result and support strong
radiational cooling into the lwr to mid 30s F; and as such, a Frost
Advisory has been issued for those areas. Local policy is for
issuance of Frost Advisory when forecast temperatures are in the 33-
36 F range under good radiational cooling conditions, regardless of
RH. And while surface (2-meter) dewpoints will likely be in the 20s
F over the Advisory areas tonight, with associated marginal RH
values for frost development, ground-level RH should be higher and
adequate for at least patchy frost development.


KEY MESSAGE 2... Weather parameters will be supportive of Increased
Fire Danger today, with brief Red Flag conditions possible over the
northern Piedmont and northern Coastal Plain.

At the base of a trough that will progress across ern Canada and the
nrn Middle Atlantic and Northeast through tonight, an observed 55 kt
speed max at 700 mb at ILX last evening is forecast to strengthen in
excess of 60 kts across the lwr OH Valley and Virginias this
morning, then weaken through the 40s kts while progressing across
and offshore NC this afternoon and evening. Dry, wnwly flow in the
lee of the srn Appalachians will favor the development of a deeply-
mixed boundary layer up to 8-10 thousand ft AGL over cntl NC today,
which will increase the likelihood of momentum transfer from the
aforementioned 700 mb speed max. So while wly surface winds will
already be strong and gusty surrounding the reinforcing, moisture-
starved cold front noted above, into the 20s kts and strongest
around 30 kts across the nrn Piedmont and nrn Coastal Plain,
momentum transfer from stronger flow above may support a few higher
peaks in the 30-40 kt range. Indeed, similar gusts were noted in
proximity to the surface front and 700 mb speed max across IL, IN,
and OH Sun afternoon, with some in excess of 40s kts where weak
convection diabatically-accelerated gusts. Additionally, RH values
are expected to decrease below 30% by noon and reach 15-25% minimums
this afternoon, lowest over the srn Piedmont and Sandhills. While
brief Red Flag conditions cannot be ruled out, especially where
winds are forecast to be strongest and longest over the nrn Piedmont
and nrn Coastal Plain, and where RH will likely be around 25%, a
relative lack of spatial overlap of highest winds north (eg. nrn
Piedmont and nrn Coastal Plain) and lowest RH south (eg. srn
Piedmont and Sandhills), should preclude widespread Red Flag
conditions.


KEY MESSAGE 3... Temperatures will be above normal through the
extended forecast period. Generally dry through the end of the work
week, rain possible over the weekend.

Aloft, a s/w disturbance will slide sewd across the region Wed/Wed
night as the longwave ridge progress ewd across the Midwest. The
ridge will continue slowly ewd to over the East Coast where it will
flatten out over the weekend as another s/w disturbance moves ewd
across the region. At the surface, the high will sit off the
Southeast/Carolina coast Wed/Wed night as a low tracks ewd across
the nrn mid-Atlantic. A backdoor cold front may approach from the
northeast Fri/Fri night, but should stay well northeast of the area
as another low tracks sewd across the OH Valley and mid-Atlantic Fri
and Sat. However, there are some timing differences amongst the
available guidance and forecast uncertainty increases beyond Fri.
The weather should largely remain dry through the week, with no
significant rainfall expected. The best (but still uncertain) chance
for rain will be over the weekend, however there could be a fleeting
shower with the s/w passage Wed/Wed night, mainly across the
northeast Piedmont/nrn Coastal Plain. Above normal temperatures
expected through the extended forecast period.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
As of 735 AM Monday...

There is high confidence in VFR conditions through 12Z Tue. A band
of generally broken altocumulus based around 7-9 thousand ft AGL, and
associated patches of virga, will progress sewd along and ahead of
an otherwise moisture-starved cold front that will move through cntl
NC this afternoon through evening. Wswly to wly surface winds will
develop and strengthen with daytime heating ahead of that cold
front, then gradually veer through nwly with its passage, before
lessening around sunset.

Outlook: Dry, continental air will favor continued, VFR conditions
over cntl NC this week.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 2 AM to 8 AM EDT Tuesday for NCZ007>011-021>028-
038>043-076.

&&

$$

DISCUSSION...MWS/KCP
AVIATION...MWS