279
FXUS62 KGSP 021427
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1027 AM EDT Sun Jun 2 2024

.SYNOPSIS...
Moisture will increase today as surface high pressure shifts
offshore. As such, showers and scattered thunderstorms can be
expected. A typical summer pattern will return during the first half
of the week with daily afternoon thunderstorm chances. Showers and
thunderstorms will likely increase in coverage for Wednesday and
Thursday as a cold front approaches our area, with drier weather
expected to return by the end of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 10:05 AM Sunday...shower coverage has diminished over our CWA
during the past few hrs. A more well-defined line of heavier showers
with a few embedded thunderstorms further south is about to move into
our western-most NC zones. It`s doubtful that we will see much (if any)
thunder/lightning over the next few hrs, as no significant instability
is expected to materialize over our area until this afternoon.

Otherwise, upper ridging continues to shift east today as a baggy s/w
trof crosses the FA. Little forcing will be had with this feature as
it supports a weak sfc bndry pushing east during max heating. Soundings
show lowering saturation of the column today and limited available
sbCAPE or even muCAPE for that matter. A couple of the more unstable
models indicate arnd 800 j/kg of afternoon CAPE, while other guidance
is holding arnd 300 J/kg less. Little shear will be had as well, with
profiles consistent with less than 15 kts 0-6km shear. Also, with the
weak upper trof, mid-level LRs remain unremarkable. So, still expect
isolated to sct thunderstorms developing ahead of a loose sfc conver-
gence zone aft 17z continuing thru 00z, yet the prospect of severe
criteria being met is low. Highs today will will be held about 5 to
7 degrees below normal due to deep moisture. Mins drop to near normal
levels with a chance of dense fog before daybreak. The exact location
of fog formation is unclear currently and will roughly depend where
the heavier rain falls this afternoon. But for now the NC mtn valleys
have the best chance for dense fog.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 213 AM Sunday: A typical summer pattern will return to the
area to kick off a new work week on Monday. Surface high pressure
offshore will allow for persistent onshore flow and modest moisture
flux into the western Carolinas and northeast Georgia. Aloft, a belt
of weak westerlies with several embedded shortwave troughs will
extend from the Southern Plains into the Southern Appalachians. Low-
level temperatures will rebound with afternoon highs climbing into
the upper 70s to mid 80s on Monday with a warming trend continuing
into Tuesday with low to upper 80s common. A few readings around 90
degrees will be possible across the Charlotte metro and lower
Piedmont. Scattered diurnal showers and thunderstorms will also be
possible each day with convection initiating over the mountains
during the late morning and moving into the Upstate and North
Carolina foothills through the afternoon. Forecast soundings are
rather unimpressive, however, with poor thermodynamic profiles
characteristic of tall/skinny CAPE and near moist adiabatic lapse
rates. This will tamper updraft intensity with further complications
from water loading. Thus, while a few strong storms with locally
gusty wet microbursts cannot be discounted, a more robust severe
weather threat is not expected.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 227 AM Sunday: By the middle of the week, an intense Pacific
jet moving into the Pacific Northwest will carve out a potent
negatively tilted trough across the Northern Plains. This trough is
then forecast to slide east across the Midwest and into the Great
Lakes region by Thursday. The strongest large scale height falls
will remain displaced to our north, but at least modest forcing
should grace the Southern Appalachians within increasing flow aloft.
This will promote a noticeable uptick in rain chances Wednesday into
Thursday as better forcing works on a rather moist airmass
entrenched across the region. Any severe weather threat remains
uncertain as destabilization will be tied to the extent of cloud
cover. A low-end severe weather threat may be realized should
moderate destabilization occur, but will need to be assessed closer
as the event nears. With time, guidance is in good agreement that
the trough will evolve into a massive closed upper low centered over
northern Michigan. An attendant surface cold front will approach the
area Thursday with the frontal passage expected on Friday. This will
usher in another dry airmass for the weekend.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: The weather becomes more active today as a
weak, yet moist, sfc bndry pushes in from the west. Have all
terminals seeing increasing chance of vicinity showers before
daybreak and PROB30 thunder chances during the afternoon, generally
beg 17z west and 18z east. Restrictions will be limited to lowering
CIGs to MVFR after the tstms weaken and push east during the latter
period. Could see IFR or lower VSBY near daybreak Mon across the TAF
sites and this potential will be addressed with the 12z TAF set.
Winds remain rather low-end and generally s/ly to sw/ly as broad sfc
ridging persists associated with a sfc high stationed off the Atl
coast.

Outlook: Diurnal shower and thunderstorm chances with associated
restrictions will linger through the middle of next week.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$

SYNOPSIS...TW
NEAR TERM...JPT/SBK
SHORT TERM...TW
LONG TERM...TW
AVIATION...JPT/SBK