Area Forecast Discussion Issued by NWS Raleigh/Durham, NC
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000
FXUS62 KRAH 190052
AFDRAH
Area Forecast Discussion
National Weather Service Raleigh NC
850 PM EDT Mon Mar 18 2024
.SYNOPSIS...
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A vigorous upper-level disturbance and reinforcing surface cold
front will move across the area tonight. Canadian high pressure will
follow and build across the Southeast through midweek.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 850 PM Monday...
Satellite imagery reveals a nice blossoming of clouds and colder
cloud tops over central NC. This is in association with the vigorous
upper-trough and shortwave moving through the region at the moment.
The deepest lift with this trough will be between 8 pm and 2 am.
After that, the trough is expected to lift off the coast. Local and
regional radar shows some echoes over the southern Piedmont, but we
have yet to see any observations reporting any measurable rain.
Forecast soundings show a fair bit of dry air below 5 kft. However,
as the trough slides eastward, the GFS and NAM-NEST show decent
moistening of the column between 850 and 700 mb and in the mixed-
phase region. This is most prominent along a line from Fayetteville
to Goldsboro and points east. While the low-levels are dry with
dewpoints crashing into the teens and 20s, we did increase PoPs to
around 30-percent mainly SE of the Triangle and southern Coastal
Plain. Most of the echoes on radar will be virga given the dry air
at sub-cloud layer, but there should be enough forcing to squeeze
out some patchy light rain in these areas.
The freeze warning remains in effect for the southern Piedmont.
Given some recent model guidance, we lowered lows a few degrees in
the typical cooler spots as winds relax toward sunrise and CAA
maximizes. Before winds die down, gusts out of the NW of 25-30 mph
will be common before midnight. Lows will range from the upper 20s
to low 30s in the western/southern Piedmont and low to mid 30s in
the Sandhills to Coastal Plain.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
As of 400 PM Monday...
Strong flow aloft will develop Tuesday with a strong ridge along the
West Coast and a deep low across SE Canada. At the surface, high
pressure will build further east into the Deep South, switching
surface flow from westerly to southwesterly across central NC. Winds
will strengthen during the day due to the approaching surface high
and a deep low moving SE, just north of the Great Lakes. Wind gusts
of 20 to 25 mph are possible across much of the area. A dry airmass
across the region will help dew point temperatures drop into the
teens Tuesday afternoon, and with highs approaching the mid to upper
50s, relative humidity will lower to 20 to 30 percent across most
areas. With dry fuels in place across much of the area, an Increased
Fire Danger Statement has been issued for the northern Piedmont,
Coastal Plain and eastern Sandhills for late in the morning through
early evening.
Winds will somewhat diminish in the evening, and with clear skies,
good radiational cooling will make for a chilly night with lows near
normal to 5 degrees below normal. Increasing thicknesses will keep
most areas from dropping below freezing.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
As of 320 PM Monday...
By Wednesday morning, low pressure will be centered over
southeastern Ontario with a cold front extending to the southwest,
with the influence of high pressure contained close to the Gulf
Coast. The cold front will move across the area from northwest to
southeast during the afternoon/evening hours, bringing an increase
in wind during that period. The dry conditions that have been
present through the week will continue both Wednesday and Thursday,
although the wind speeds will be less behind the front on Thursday.
The combination of higher wind and low relative humidity could bring
an increased fire danger on Wednesday. The frontal passage itself
will not bring any precipitation itself as there won`t even be much
moisture for cloud cover.
Behind the cold front, high pressure will extend southeast from
central Canada into the Carolinas on Thursday. The high will shift
east Thursday night, and by Friday morning, rain will be approaching
the area from the southwest related to a developing low over the
Gulf of Mexico. The GFS/GEFS has consistently remained a quicker
solution compared to the ECMWF/EPS, especially in regards to the low
center, but there is enough agreement between models to increase
pops to likely for all locations except the northwestern quadrant of
the forecast area Friday afternoon/night. The 12Z GFS shows the low
over the Delmarva Peninsula Saturday morning, while the 12Z ECMWF
still has the low center off the coast of Georgia. Will have pops
decreasing through Saturday and Sunday, keeping some pops in case
the slower European solution does verify. All models agree that
precipitation will have moved offshore by Sunday night and Monday as
high pressure builds over eastern Canada and a ridge extends south
along the East Coast.
There is high confidence that Wednesday will be the warmest of the
next seven days in advance of the cold front, with highs ranging
from the mid 60s to the mid 70s. Temperatures should be at or below
normal through the rest of the forecast. The day with the most
uncertainty to the high temperatures is Friday, as there could be a
short-lived cold-air damming episode with high pressure briefly over
New York as the Gulf of Mexico low advances northeast. Overnight
lows will be above freezing throughout the extended period, and no
need for frost/freeze headlines is anticipated.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 745 PM Monday...
West to northwest wind gusts of 15 to 25 kt are possible this
evening as an upper disturbance moves by. Winds will slightly
diminish overnight, then increase again Tuesday and shift
southwesterly by the afternoon, with gusts around 20 kt expected.
Outlook: LLWS is possible Tues night into early Wed as winds at 2k
ft increase to 30-40 kts. A storm system approaches the area Fri
afternoon into Sat bringing a high chance for sub-VFR conditions.
Otherwise, VFR conditions are expected through the period.
&&
.FIRE WEATHER...
As of 400 PM Monday...
Elevated fire weather conditions are possible at times through mid-
week as relative humidity drops to 20 to 30 percent, and wind gusts
increase to 20-25 mph. Relative humidity will drop to the
aforementioned values in the afternoons through Thursday, however
wind gusts of 20 to 25 mph are mostly expected Tue and Wed
afternoons. With dry fuels across most areas, an Increased Fire
Danger Statement has been issued for the northern Piedmont, Coastal
Plain and eastern Sandhills for late Tue morning through the early
evening.
Refer to your local burn-permitting authority on whether you may
burn. If you do burn, exercise extreme caution.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from midnight tonight to 9 AM EDT Tuesday for
NCZ073>076-083-084.
&&
$$
SYNOPSIS...Kren/MWS
NEAR TERM...Kren
SHORT TERM...JJT
LONG TERM...Green
AVIATION...JJT
FIRE WEATHER...JJT