National Weather Service Weather Forecast Office

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

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KGSP 032046
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
446 PM EDT Fri Apr 3 2020

.SYNOPSIS...
High pressure slowly builds into the region through Saturday, then
shifts to our east on Sunday. A weak cold front will push in from
the northwest by Sunday evening, stalling over the area Monday,
before lifting back north as a warm front on Tuesday. A stronger
cold front will cross the region on Wednesday.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 440 pm Friday: The current forecast remains on track as a
flattening short wave ridge moves east from the Miss Valley/Great
Lakes region late this afternoon, and likely across the Appalachians
by the end of the period. The only minor adjustment will be to add a
touch more clouds earlier in the near term as 700 to 500 mb layer
moisture moves southeast across the southern Appalachians, along
with weak 500 mb embedded vorticity lobes surviving the ridge axis.
Otherwise, slackening winds and a dry boundary layer will allow
tonight`s min temps to cool to just a couple of degrees above climo,
moderated a bit by the increasing clouds. Tomorrow`s maxes should
again be a solid 5 degrees warmer than normal. Dewpoints creeping
into the 30s are expected to result in improving RH profiles
Saturday. See the Fire Wx discussion below for details.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 215 PM EDT Friday: The short term will be dominated by a
broad 500 mb ridge that will build somewhat across the eastern 2/3rd
of the CONUS. At the sfc, a dying cold front will approach the
Southern Appalachians from the Ohio Valley Sunday aftn, with the
latest guidance not too impressed with QPF response. There may be
just enough moisture to support isolated to widely scattered showers
in the mountains. If you throw out the GFS, the Piedmont looks dry.
The front stalls out across NC in an east-west orientation, as a
modest high pressure center enters the Northeast. The front actually
gets a little stronger on Monday thanks to some frontogenesis, and
should trigger scattered showers across the NC zones, with isolated
coverage to the south. Sbcape of 500+ J/kg may be enough for some
tstms, but given lack of strong forcing, the severe threat should
remain low despite 35-40 kt of 0-6 km bulk shear. Temps will
continue a warming trend with the building upper ridge. Highs about
5-10 deg above normal, lows 10-15 deg above normal.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 245 PM EDT Friday: a couple of impulses diving out of southern
Canada will work to flatten the eastern CONUS upper ridge Tuesday
thru Wednesday, with the second wave becoming a large vortex over
the Great Lakes by Thursday. Meanwhile, a large closed low over
California will slowly wobble east Wednesday thru Thursday. The
medium range guidance are completely all over the place with when
this low gets picked up by the northern stream and ejects east of
the Rockies. The GFS is the usual fast guidance opening it up by 12z
Friday, while the Canadian holds on to it thru the weekend. The
first wave that will drop into the Great Lakes will push a cold
front across the forecast area Wednesday. But behind that,
confidence in the forecast really goes down. I expect temps to trend
cooler, back to near normal by next Friday. Precip will be mainly
confined to the mountains, highest on Tuesday and Wednesday (mainly
chc mountains and slgt chc east), then slgt chc or less Thursday and
Friday.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: VFR will persist through the period, with
only occasional mid/high level clouds continuing. Winds will
generally be NW @ 5-10 kts at the western NC terminals late this
afternoon, although a lee trough may cause periods of variable
directions at KHKY. Winds may be light SW for partof the late
afternoon at the Upstate SC terminals. Winds become light/vrbl at
all sites this evening, and light N to NE through Saturday.

Outlook: Expect VFR conditions to persist into early next week.
Flight restrictions may return on Tuesday as moisture increases
ahead of a weak front.

Confidence Table...

            20-02Z        02-08Z        08-14Z        14-18Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High 100%     High 100%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High 100%     High 100%

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

www.weather.gov/gsp/aviation

&&

.FIRE WEATHER...
Widespread dewpoints in the 20s to lower 30s is (or eventually will)
result in RH bottoming out in the 15-25% range across much of the
forecast area this afternoon. After coordination with NWS KFFC, a
Fire Danger Statement will be issued for our GA counties into the
early evening hours. Winds generally remain in the 5-10 mph range,
although some gusts of 15-20 kts are possible, especially across
western NC. A Fire Danger Statement remains in effect for Upstate SC
(The SCFC has since opted to issue a "Red Flag Fire Alert" for the
entire state. We usually let that speak for itself, but since the
FDS has already been issued, we`ll let it ride out to avoid
confusion.) A FDS also remains in effect for the NC Piedmont this
afternoon. Weaker winds as well as increasing dewpoints (yielding
min RH in the 25-35% range) are expected Saturday, thus no
additional products are expected at this time.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Fire Danger Statement until 8 PM EDT this evening for GAZ010-
     017-018-026-028-029.
NC...Fire Danger Statement until 8 PM EDT this evening for
     NCZ035>037-056-057-068>072-082-501>510.
SC...Fire Danger Statement until 8 PM EDT this evening for
     SCZ001>014-019.
     Fire Danger Statement from Saturday afternoon through Saturday
     evening for SCZ001>014-019.

&&

$$
SYNOPSIS...ARK
NEAR TERM...HG/JDL
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...HG/JDL
FIRE WEATHER...JDL