Area Forecast Discussion
Issued by NWS Greer, SC
FXUS62 KGSP 301454
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1054 AM EDT MON MAY 30 2016
The remnants of Bonnie will slowly lift northeast along the coast of
the Carolinas today through Wednesday. Moisture will increase ahead
of a cold front approaching from the northwest Thursday through
Friday. The front will move through the region on Saturday but
likely stall nearby over the weekend.
.NEAR TERM /THROUGH TONIGHT/...
As of 1035 AM EDT...Pretty quiet around the CWFA ATTM, with
a few cu developing over the mtns but otherwise no convective
activity. Consensus of CAM guidance shows initiation of SHRA/TSRA
along and just south of the Blue Ridge Escarpment within the next
90 mins or so, this activity then propagating slowly southward
into the Piedmont. The same guidance shows little development
over the I-77 corridor, where bands of clouds associated with
the remnant of Bonnie will persist into the aftn. However with
CAPE fcst to approach 1000 J/kg in that area, a chance-range PoP
seems appropriate. Have updated PoPs and sky cover into early
evening, per these points.
The center of the remnant circulation of Bonnie will move little
today...drifting slightly east to around Myrtle Beach today
thru tonight. This should result in the cloud shield shifting
east...allowing the western 2/3rd of the CWFA to see more sun today.
Temps will rebound to above normal readings where the sun breaks
out. There will also be more INSTBY and scattered showers and a
few garden variety TSTMS may develop...favoring the eastern Blue
Ridge escarpment. With more clouds...the I-77 corridor will likely
remain about a category below normal.
Tonight looks similar to the past night...with lingering cloud cover
and a few spotty light showers across the eastern 1/3rd of the CWFA.
Temps will drop to 50s mtns and lower to mid 60s piedmont.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
At 300 AM EDT Monday: The remnant Bonnie circulation will lift
slowly northeast along the coast of the Carolinas Tuesday through
Wednesday. Warm and humid air will remain in its wake across the
western Carolinas and northeast Georgia. Scattered, mainly mountain
convection is indicated among the models for Tuesday and Wednesday
afternoon and evening. The light steering flow up the column will
create a heavy rain threat with any thunderstorms that form.
Instability appears much better on the NAM than the GFS given the
higher dewpoints, but moist vertical profiles should limit the
severe thunderstorm potential. Expect maxes to run about a category
above climo each afternoon, with mins two categories above climo
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 300 AM EDT Monday: Deeper layer southwesterly flow will
develop on Thursday as a northern CONUS low pressure system moves
into the western Great Lakes. Diurnal shower and thunderstorm
coverage will increase - especially over the mountains. The deeper
moisture will continue to pool ahead of an approaching cold front on
Friday with likely PoP to be advertised across the mountains and NC
foothills and solid chances southeast. Friday may be the warmest day
of the week with plenty of upper 60s lows and upper 80s highs.
The cold front will move through the region from the northwest on
Saturday but possibly stall just southeast of the region by late
day. Low levels never really dry out and another reinforcing cold
front will approach from the northwest on Sunday. In addition, upper
jet support may return along the southern Appalachians on Sunday as
height falls aloft carve out to the west. Chance PoPs for convection
will linger each day, but temperatures will gradually cool.
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
At KCLT...Low MVFR stratocu are developing among breaks in low
stratus which developed earlier this AM. These will take some time
to mix up to VFR level. Depending on how peristent clouds are over
the area, there may be enough breaks to allow enough heating for
a few shra and tsra to develop. The latest guidance favors the
Blue Ridge escarpment to the west, but flow tries to take it SE
toward the terminal late this aftn. Though meso models generally
do not depict activity impacting KCLT directly, this is a plausible
scenario, and a TEMPO for TSRA is being retained as of 15z AMD. Low
clouds may develop again tonight, as moisture continues to stream in
from the east. So have MVFR CIGS return after midnight tonight. NE
winds around 5-8 kts expected thru the period.
Elsewhere...Now that MVFR clouds have dissipated or moved east, all
the TAF sites should remain VFR away from any TS this aftn. Guidance
still showing better instby today as there should be more sunshine
across the area. Mainly TEMPOs and PROB30 for scattered convection
from mid aftn thru early evening. Winds will continue to be N to
NE and generally under 10 kts thru the period.
Outlook: Bonnie is expected to move very slowly up the coastal
Carolinas over the next several days. Lingering shower chances into
the early part of the week would be greatest at KCLT. Otherwise,
patchy fog chances continue at KAVL each morning, with scattered
afternoon/evening SHRA/TSRA increasing throughout during the week.
15-21Z 21-03Z 03-09Z 09-12Z
KCLT High 96% High 100% High 100% High 88%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 100% High 100% Med 77%
KHKY High 100% High 85% High 100% High 94%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% High 94%
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: