National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS62 KRAH 170702
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
302 AM EDT Wed Apr 17 2024

.SYNOPSIS...
A warm front across NC will lift north into VA early this morning. A
weak cold front will move east across the region tonight and
early Thursday. A stronger cold front will more across the area
late Friday into Saturday and then linger to our south.
&&

.NEAR TERM /THROUGH TONIGHT/...
As of 250 AM Wednesday...

* Two chances of rain, mainly spotty and patchy light rain this
  morning toward midday across the mainly the western Piedmont
  with some scattered showers and possibly a storm later this
  afternoon and especially this evening.

The latest surface analysis shows a warm front extending from
southwestern VA southeast across the Triangle region into eastern
NC. North of the front surface dew points are mainly in the 40s
while south of the front dew points are in the upper 50s to even the
lower 60s. Further aloft, short wave ridging is noted across
the Carolinas into the mid-Atlantic with a couple of mid/upper
level disturbances noted at the nose an eastward advancing
speed max across the eastern TN Valley. The thunderstorms that
developed across the Sandhills on Tuesday evening dissipated
several hours ago and skies are partly cloudy with mainly high
clouds.

The warm front will lift north into VA this morning. At the same
time the mid/upper level disturbance across the TN Valley will shift
east and move across the Carolinas and VA this morning and early
afternoon. This feature is producing some spotty rain/showers early
this morning across eastern TN, far northern GA and far southwest
NC. This light precipitation may spread into the western Piedmont
and Triad areas between 8am and noon. The precipitation should
diminish as it moves east but a little spotty rain may reach
the Triangle area toward midday with mainly dry conditions
elsewhere through the early afternoon. A second threat of rain
is associated with a weakening cold front that will begin to
move east across NC late tonight. This feature may produce some
isolated showers across the western Piedmont late this afternoon
with scattered showers and possibly a thunderstorm expected
across the eastern Piedmont, Triangle, Sandhills and Coastal
Plain late this afternoon and especially this evening. Coverage
should be limited and storms are not expected to be strong.
Otherwise, expect thickening high clouds today with mostly
cloudy skies are expected this afternoon and evening. Skies
will clear from the northwest late tonight. Highs today will
mainly range in the lower 80s with temperatures a little cooler
near the VA border with some mid 80s possibly near the SC
border. Lows tonight will mainly range in the lower 60s. -Blaes
&&


.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 300 AM Wednesday...

* Warm with highs 10 to 15 degrees above average.

A weakening cold front will move across the eastern Carolinas
on Thursday morning and off the coast during the afternoon. A
northwest flow aloft will develop on Thursday with the flow
becoming more westerly on Thursday night. This flow will result
in dryer air moving into the region with PW values dropping
below an inch with surface dewpoints ranging in the upper 40s to
lower 50s. Lingering clouds on Thursday morning will give way
to mainly clear skies and fair weather that should continue
into Thursday night. Highs on Thursday will mainly range in the
mid to upper 80s with some lower 80s near the VA border. These
highs are about 10 to 15 degrees above average. Mild low
temperatures Thursday night will range in the mid 50s to around
60. -Blaes

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 355 PM Tuesday...

A surface low over southern Ontario will weaken and get absorbed by
another low to its NW on Thursday, as a secondary low develops off
the Delmarva/southern NJ coast and slowly drifts east. An associated
decaying cold front will move through central NC in the morning. But
there will be no drop in temperatures behind it. In fact, mostly
sunny skies and shortwave ridging aloft will help bring temperatures
back into the 80s areawide on Thursday, maybe even touching 90 in a
few spots in the far south. Lows Thursday night will also be above
normal, in the mid-50s to lower-60s.

Mid/upper ridging will move offshore on Friday and get replaced by
weak shortwave troughing and height falls. At the surface, a warm
front will lift north through central NC, while a much stronger cold
front begins to approach from the NW and a surface low develops
along it and moves east across the Carolinas. This will bring the
next chance of showers during the afternoon and evening, and
ensemble guidance has trended significantly wetter compared to
yesterday. So POPs are increased to chance across the area. With
models showing CAPE as high as 500-1000 J/kg particularly across the
south, a few storms can`t be ruled out. Mid-level flow around 25-35
kts on the GFS and ECMWF isn`t too impressive and borderline for any
kind of severe threat, but will need to watch over the next few
days. Forecast highs on Friday are a bit cooler than Thursday in
most places, ranging from upper-70s to mid-80s, except still upper-
80s in the far south. Lows Friday night are again expected in the
mid-50s to lower-60s as precipitation chances diminish but some
cloud cover remains.

Overall, model guidance has come into better agreement for the
pattern this weekend. Saturday now looks drier and cooler, as the
ECMWF trended toward the GFS in depicting a faster cold frontal
passage through central NC in the morning and afternoon. Forecast
highs are in the mid-70s to lower-80s. POPs are only slight on
Saturday and Saturday night, before increasing to chance areawide on
Sunday and Sunday night (highest SE) as the next wave of low
pressure rides along the front. With models showing the front to our
south, we would be on the cool and stable side which would preclude
any chance of storms and would result in more stratiform rain. But
confidence in these details is still not high until we see more run-
to-run consistency. Confidence on amounts is even lower as the GFS
is more suppressed with the front and largely keeps the rain to our
south, while the ECMWF brings heavier amounts into our region.
Ensemble guidance is all over the place with around half of the GEFS
bringing us measurable rain.

We will largely dry out by Monday as the surface low moves away into
the Atlantic and cool high pressure begins to build in from the
west. High temperatures will only be in the 60s with lows in the
40s. Tuesday will be mostly sunny with temperatures increasing back
to near normal (lower-to-mid-70s).

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
As of 220 AM Wednesday...

While VFR conditions are generally expected across central NC over
the 24 hour TAF period a couple of disturbances will produce some a
little bit of precipitation across the area. First there is a very
small threat of some localized and short lived MVFR CIGS across the
southern Coastal Plain and eastern Sandhills around daybreak this
morning as some stratus may spread into the area. A mid and upper
level disturbance will move east across the southern Appalachians
and NC/VA this morning will will spread some enhanced cloudiness
along with some spotty light rain in mainly VFR conditions that will
move across the Piedmont this morning into the afternoon. VFR CIGS
and mainly VFR VSBYS are expected with all of the precipitation. A
weakening cold front will move east across the Carolinas tonight
providing a threat of widely scattered showers and perhaps a
thunderstorm late this afternoon and evening. The best chance of a
shower across the Triad terminals will be between 23 and 03Z with a
slightly better chance of showers and perhaps a thunderstorm at
KRDU/KFAY/KRWI from 00Z to 05Z, again in mainly VFR conditions are
expected during this time with a brief VSBY reduction to MVFR in
precipitation. Conditions will improve from west to east this
evening with clearing skies from the northwest late tonight.
Light mainly southerly winds early this morning at 7kts or less
will become south to southwesterly at 8 to 10kts with gusts of
16 to 20kts late this morning and especially this afternoon.
Light southwest winds at 6 to 10kts area expected tonight.

Looking beyond 06Z Thursday, VFR conditions are generally expected
through early Friday. A cold front will approach on Friday
bringing a threat of adverse aviation conditions in showers and
storms Friday afternoon into early Saturday with another chance
of rain and showers late Sunday into Monday. -Blaes

&&

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

&&

$$

SYNOPSIS...Blaes
NEAR TERM...Blaes
SHORT TERM...Blaes
LONG TERM...Danco
AVIATION...Blaes