842
FXUS62 KRAH 281756
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
1255 PM EST Fri Feb 28 2025

.SYNOPSIS...
High pressure will build across the Southern states through tonight.
A cold front, strong but mostly dry, will push through the area
Saturday afternoon. Chilly high pressure will build in from the
northwest on Sunday, and settle over the East Coast on Monday.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 1025 AM Friday...

* Increased fire danger today due to low relative humidity, gusty
  winds of 10-20 mph, and changing wind direction from northwest
  this morning to southwest this afternoon and evening.

Only slight tweaks were made to the forecast for today, mainly to
temperatures and RH. Latest bias-corrected statistical guidance and
dry adiabatic forecast techniques resulted in temperatures 1 to 3
degrees warmer for today and now range from the low 60s (NE) to
upper 60s to near 70 across the south. Additionally, point soundings
show an abundant amount of dry air in the low/mid levels to mix into
through the afternoon hours and blended lower dewpoints more heavily
with RAP/HRRR guidance which do well in deeply mixed regimes.
Otherwise the forecast is on track and the previous discussion from
240 AM Friday follows.

Mostly sunny and dry weather today, with lighter winds. GOES layer
WV imagery shows well the potent shortwave trough now swinging
through E NC and E VA, while at the surface, the cold front is
pushing ESE through the central/srn NC coast, with falling dewpoints
in the 20s and 30s behind it across central NC. A few radar returns
are noted to our NW and N in the fast NW flow, and some of the
mostly mid clouds from this are working into our far NW, but
otherwise skies are mostly cloud-free and likely to stay that way
through tonight, marred only by some brief high thin cloudiness
spreading in from the Midwest. Factoring in projected near-normal
low level thicknesses, weak and waning CAA, and plentiful sunshine,
expect highs to be a bit above normal, near 60 N to mid-upper 60s S.
With fair skies and a light SW breeze, expect mild lows tonight in
the 40s.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 305 AM Friday...

The potential for adverse fire behavior will be a primary concern
Sat (see discussion below). We`ll be firmly in the warm sector ahead
of our mostly dry clipper cold front approaching from the NW, with
blustery winds from the WSW shifting to W. Deep mixing up to 800-750
mb will allow us to tap into 20-30 kts W winds in the mid to upper
reaches of the mixed depth, yielding gustiness from late morning
through the evening. The column will be quite dry in the low levels
with an inverted V signal, however we will see a period of partly to
mostly cloudy skies Sat afternoon into the evening and night with
high-based stratocu near the top of the mixed layer. Clouds should
be thickest and most numerous across our N and NE. The cold front is
expected to push SE through central NC during the mid-late
afternoon, ahead of the incoming mid level shortwave trough axis,
although despite the wind shift to NW post-front, temps will take
awhile to fall as the most dense air associated with the incoming
chilly surface high centered over the Upper Midwest is initially
held up by the Appalachians. Our low level thicknesses Sat will be
well above normal with WAA for much of the day (becoming neutral
advection or very weak CAA late), supporting warm highs in the mid
60s to mid 70s, despite the afternoon increase in clouds. Colder and
drier air will spill in overnight with decreasing clouds late, so
expect lows in the upper 20s to mid 30s. -GIH

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 400 AM Friday...

The extended period will start off dry and sunny on Sunday with
strong subsidence behind the departing shortwave. High temperatures
will be 10-15 degrees below normal, in the mid-to-upper-40s, as cool
high pressure builds in from the NW. Lows Sunday night will drop
into the lower-to-mid-20s for much of the region based on the latest
statistical guidance, as there should be clear skies and calm winds
with the surface high centered over the Mid-Atlantic. The high will
begin to shift to the coast on Monday and offshore on Monday night,
setting up southerly return flow and commencing a warming trend.
Monday`s forecast highs are in the lower-to-mid-50s with Monday
night`s lows in the lower-to-mid-30s. Meanwhile mid and high clouds
will begin to spill into the region in advance of a mid-level low
over the Desert Southwest that initiates surface cyclogenesis over
the Central Plains.

Above-normal temperatures will return on Tuesday as the offshore
surface high moves farther east and the surface low deepens over the
mid-MS Valley, strengthening the southerly low-level flow. Highs
will reach the 60`s and Tuesday night`s lows will only drop into the
lower-to-mid-50s under mostly cloudy to overcast skies. As Gulf and
Atlantic moisture stream into the area, the GFS and a minority of
its ensembles depict some patchy light rain on Tuesday and Tuesday
night, though other guidance is dry. For now just carry slight
chance POPs in the NW. A much better chance of showers comes on
Wednesday as both the GFS and ECMWF depict an intense cyclone
centered near Chicago that moves NE into southern Ontario and Quebec
which drags a cold front through central NC. The trough looks quite
deep and the moisture return impressive, with PW values 200-300% of
normal and raw guidance depicting dew points reaching the lower-60s.
This along with temperatures reaching the upper-60s to mid-70s
should support at least weak instability, on the order of 200-500
J/kg according to the latest guidance. The wind field is also quite
strong, and ensemble means depict deep layer shear on the order of
60-70 kts. So the SPC last night issued a rare 15% severe
probability on Day 7 from GA into the Carolinas. While model
agreement on the strength and track of the low is good, the main
difference comes in timing as the GFS brings the heaviest
precipitation through in the morning and afternoon while the ECMWF
holds off until the late afternoon and evening. So for now brought
POPs below NBM and capped them in the high likely range (~70%).

As NW flow takes over, cooler and drier air will advect into the
region behind the cold front on Wednesday night and Thursday.
Thursday`s forecast highs are back to slightly below normal, in the
mid-50s to lower-60s. Can`t rule out some lingering isolated showers
on Wednesday night and early Thursday as a separate northern stream
trough swings through, so have slight chance POPs in the east, but
any additional amounts would be light.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
As of 100 PM Friday...

VFR conditions will continue across central NC for the next 24
hours, with a few high clouds developing across the region this
afternoon. Currently (18z) surface winds of 5-10 kts with infrequent
gust up to 20kts are from the NW but will quickly shift to a
lighter/non gusty SW wind later this afternoon and early evening. By
around 05z tonight, LLWS is possible at all TAF sites with light
surface winds and stronger winds of 35-45 kts aloft. LLWS conditions
should subsided by sunrise where winds will generally mix down to
the surface. This mixing will result in gusty conditions (20-25kts)
beginning early Saturday morning and lasting through much of the day
Saturday.

Beyond 18Z Sat: While VFR conditions are expected through at least
Tuesday, mid clouds based at 5-7kft AGL are expected Sat afternoon
and evening with the passage of a mostly dry cold front. Sub VFR
conditions are expected to begin as early as late Tuesday evening
and continue through Wednesday as a strong frontal passage will move
through the region.

&&

.FIRE WEATHER...

The risk for adverse fire behavior will be very borderline today,
but much greater on Sat. Today we`ll see low RH values, falling to
19-27% today, as fine fuels (1- and 10-hr) remain on the dry side,
with our rainfall in the last week well below normal (including just
small amounts Thu). However, our winds will not be particularly
strong today, peaking around 10-12 mph with only sporadic gusts at
most. That said, given the drying fine fuels and low RH, will go
with an Increased Fire Danger Statement for today. Sat is even more
concerning, with RHs still low (20-30%) and frequent gusts of at
least 20-30 mph expected, warranting at least an Increased Fire
Danger Statement for Sat as well. Will continue to consult with
forestry officials later today through Sat. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Hartfield
NEAR TERM...Swiggett/Hartfield
SHORT TERM...Hartfield
LONG TERM...Danco
AVIATION...CA
FIRE WEATHER...Hartfield