Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 311330

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
930 AM EDT TUE MAY 31 2016

The remnants of tropical system Bonnie will slowly lift northeast
along the Carolina Coast over the next couple of days. Moisture will
increase ahead of a weak cold front approaching from the northwest
on Friday. The front will stall in the vicinity over the weekend,
but a stronger cold front will push through the region on Sunday


As of 920 AM EDT...A small area of light radar returns is present
between Taylorsville and Statesville, this activity having very
slowly moved out of Wilkes Co. and expanded over the past 90 mins
or so. It likely resulted from a slightly buoyant elevated parcel
which was forced up by slight low level convergence. Can`t say
this won`t occur in other areas of cloud cover. Still looking like
today will evolve much like yesterday w.r.t. mountain convection
expanding southward, so I blended the observed PoP/Sky expanse
into a CAM-based early aftn grid. I expect coverage will remain
isolated in the early aftn.

Otherwise...The remnant circulation of Bonnie will remain
near the Myrtle Beach area today, as it continues its eastward
drift. This will keep a NELY low-mid level flow over the CWFA today.
Guidance in good agreement on a little bit higher CAPE this aftn
than yesterday. The NC Mtn activity will then try to survive as it
drifts toward the south into the piedmont thru the evening. Coverage
should be slightly greater this aftn on account of the higher
CAPE. One storm became marginally severe yesterday. So we would
not be surprised if a couple of the strongest storms produced
large hail and/or downed a couple trees today. Temps will be above
normal, in the 70s to lower 80s in the mtns and mid to upper 80s
in the piedmont.

Tonight...convection should gradually wane leaving a fair amount
of debris cloudiness around thru much of the night within weak flow
aloft. Temps will continue to be a couple categories above normal,
with lows mainly in the 60s.


As of 245 AM EDT Tuesday: Upper level heights will briefly build
over the region on Wednesday as the remnant circulation of Bonnie
moves northeast along the NC coast and a prominent northern tier
trough moves slowly east from the Dakotas to the Great Lakes.
Convection will initiate once again over the mountains Wednesday
afternoon, move off into the adjacent foothills through evening, and
then largely dissipate overnight. Expect more instability late Wed
than will be observed on Tuesday, with an uptick in severe
thunderstorm potential.

Ridging will persist over the southeast Thursday into Friday as a
southern stream closed low develops and lingers over TX. Diurnal
convective coverage will likely increase a bit further, with
initiation again over the mountains by mid afternoon but with
perhaps more coverage advecting east into the piedmont. Instability
should be the highest of the week on Thursday afernoon/evening, with
plenty of 2500 to 3000 J/kg SBCAPE values across the region and
scattered severe storms quite possible. A weak cold front will
slowly approach from the northwest during this period and then
finally settle southeast through the region Friday night, or
gradually dissipate. Maximum temperatures through the period will be
slightly above climo, with mins a good 5 to 10 degrees above climo.


As of 245 AM EDT Tuesday: The southeast ridge will slowly break down
over the weekend as the digging Great Lakes system starts to carve
out an eastern trough. Although a weak fropa may start off the
period, boundary layer moisture will not dry out appreciably and
additional diurnal convection is likely by Saturday afternoon and

Better forcing, moisture, and shear will come together on Sunday as
heights continue to fall aloft. Upper jet divergence should arrive
along the southern Appalachians, and southwesterly 850 mb flow will
increase to permit slightly better storm organization ahead of the
next approaching cold front. This stronger front is expected to
cross the region Sunday night into Monday - with drying developing
everywhere but the TN border area in weak but moist upslope flow.
Temperatures will fall to near or just below climo on Monday.


At KCLT...Only patchy light fog at some of the neighboring sites
this morning, but so far the CLT obs have been VFR. With more
sunshine today, expect a little greater coverage of convection this
AFTN, and will continue a TSRA mention with a tempo for late AFTN into
early evening. Winds will continue to favor a NE direction and
remain light thru the period.

Elsewhere...Less fog developed than the guidance was forecasting,
partially due to stubborn mid clouds over KAVL and the Upstate
sites. So will start all sites VFR at 12z. Still expect another
round of showers and TSTMS ACRS the mtns. The flow should take this
activity generally south into the Upstate and NC foothills again
late AFTN thru the evening. All sites will feature PROB30 for TSRA. Winds
will continue to favor a N to NE direction today and remain light.

Outlook...Bonnie`s remnant low is expected to move very slowly up
the coastal Carolinas over the next several days, maintaining
increased precip and morning stratus chances at KCLT. Otherwise,
patchy fog chances continue at KAVL each morning, with scattered
afternoon/evening SHRA/TSRA increasing in coverage throughout during
the week.

Confidence Table...

            13-19Z        19-01Z        01-07Z        07-12Z
KCLT       High 100%     High 100%     High 100%     High  98%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High 100%     High  83%
KHKY       High 100%     High 100%     High 100%     High  96%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High 100%     High  96%

The percentage reflects the number of guidance members agreeing
with the schedule TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:




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