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000
FXUS62 KRAH 151409
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
1009 AM EDT Mon Apr 15 2024

.SYNOPSIS...
A backdoor cold front will slide southward into central NC tonight
and stall across the area through Tuesday. The front will then lift
northward through the area as a warm front Tuesday night.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 1005 AM Monday...

Only minor changes to the forecast through this evening. The
conditional threat for isolated severe storms across the northern
Piedmont and northern Coastal Plain counties remains.

The 12Z surface analysis shows a broad trough over central NC, with
the developing lee trough becoming evident. Temperatures have
already risen into the mid 60s to low 70s as of 8 AM. 12Z upper air
analyses show plenty of dry air over the area, with generally NW
flow aloft and clear skies prevailing.

The Bermuda high will continue to ridge westward into the Southeast
US today and tonight. A surface trough will likely remain in place
over central NC today, with a backdoor cold front sliding southward
into the area tonight. Aloft, a disturbance will progress eastward
through the mid-Atlantic late this aft through this eve, clipping
northeast NC along the NC/VA border. H5 height rises of 30-50m are
expected from 12Z Mon to 00Z Tue, and low level thicknesses are
expected to rise to around 1405m by 00Z Tue. Highs today are still
forecast to be in the mid 80s to around 90 degrees across central NC
today.

Previous discussion (as of 250 AM Monday): There is good agreement
that convection will blossom over central and southern VA during the
afternoon as moderate instability of 1000-1500 J/KG develops
underneath a EML in place across the region. If the storms can
overcome a less favorable storm environment of weaker CAPE and shear
and increasing BL CIN after sunset, isolated storms will be possible
across the northern Piedmont and northern Coastal Plain counties. It
should be noted that NCAR neural network probabilities have
significantly decreased from the previous 12z/14 model guidance.

Any convection should dissipate by 06z with mild overnight lows
ranging from mid/upper 50s north to lower 60s elsewhere.

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 250 AM Monday...

...Continued Unseasonably Warm...

...Scattered Afternoon Showers and Storms...

A weak stationary front bisecting the area will help serve as a
focus for scattered afternoon showers and storms as upper
disturbances crest atop the upper ridge axis as it moves into the SE
US. Moisture pooling along the front will lead to BL dewpoints
increasing into the lower 60s with weak to moderate buoyancy
developing underneath the lingering steep mid-level lapse rates.

Convection should be un-organized, but given deep layer shear of 20-
30kts, cannot rule out an isolated strong to severe storm.
Convection should fade and diminish shortly after sunset.

Highs Tuesday will be influenced by the location of the front, with
areas along and north of the front expected to see a slight cool
down. Highs ranging from lower 80s north to upper 80s south. Lows
once again in the mid/upper 50s north to lower 60s elsewhere.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 230 AM Monday...

Weak upper ridging across the Southeast Wed will flatten as a trough
lifts NE across the Great Lakes Region late in the day. Energy from
the trough will move across northern portions of central NC Wed
night as a weak low develop across the coastal Mid-Atlantic. At the
surface, high pressure will linger off the Southeast Coast, then a
cold front will approach from the west late Wed. Another warm day is
expected Wed, with widespread highs in the low 80s. Most of Wed is
expected to remain dry, then precipitation chances increase Wed
night across eastern portions of central NC as the weak wave aloft
moves by to the north across an area of increased moisture. Any
rainfall accumulations will be light, generally less than one-tenth
of an inch. Breezy southwesterly winds may develop ahead of late
Wed`s front as surface pressure gradients increase, with gusts of 20-
25 mph possible.

Although winds switch westerly behind the front, increasing
thicknesses will help highs rise into the mid to upper 80s for most
areas by the afternoon on Thu. Conditions dry out late Thu through
Fri as high pressure builds in to the north and weak ridging builds
in aloft.

Confidence then increases in the next round of showers and
thunderstorms late Sat into Sun as a few troughs dig across the
region, and a cold front pushes across the area. The details in
timing and precipitation amount still largely vary between
ensembles, however multiple opportunities for rainfall is looking
more likely through the latter half of the weekend. Cooler air may
spread across the region behind the cold front, with highs changing
from the low to mid-80s Sat to the mid-60s to mid-70s Sun.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
As of 640 AM Monday...

There is high confidence in VFR conditions through much of the 24-
hour TAF period. The exception will be with a conditional chance of
showers and storms across northern terminals, mainly INVOF KRWI and
KRDU late. Light SWLY winds will increase in the afternoon
with intermittent gusts of 15 to 20 kts. Gusts will diminish
this evening, with northern terminals seeing a northerly wind shift
overnight as the front bisects the area.


Outlook: A quasi-stationary front will bisect the area Tuesday
before moving back north Wed as a warm front. This boundary will
bring the threat of scattered showers and storms Tuesday
afternoon/early evening, especially across the northern TAF sites.
Sub-VFR fog/stratus may also be possible in rain-cooled air. VFR is
expected to prevail Wed into Fri, although showers are possible with
another boundary approaching later in the week.

&&

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

&&

$$
SYNOPSIS...KC
NEAR TERM...KC/CBL
SHORT TERM...CBL
LONG TERM...JJT
AVIATION...CBL/Kren