Area Forecast Discussion Issued by NWS Greer, SC
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000
FXUS62 KGSP 061955
AFDGSP
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
255 PM EST Sat Mar 6 2021
.SYNOPSIS...
Canadian high pressure will continue to build across the forecast
area this afternoon into tonight as a low pressure system located in
the eastern Gulf of Mexico tracks to the southeast. Dry high
pressure will gradually track east towards the East Coast tomorrow
into much of next week leading to continued dry weather and warmer
temps. Friday into Saturday a cold front will approach from the west
leading to the potential for increased rain chances.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 230 PM EST Saturday: Low clouds and sprinkles are moving
southeast out of the area as the short wave responsible for the
forcing moves southeast as well. Expect mostly sunny skies and mild
temps for the rest of the afternoon.
The upper trough strengthens over the area tonight as a channeled
short wave drops into the area. May see an increase in mountain wave
cirrus this evening as some upper level moisture moves overhead.
Some shallow low level moisture moves into the mountains toward
daybreak. This may cause an increase in clouds across the mountains,
and possibly some flurries at the highest elevations. However, no
significant precip expected given the weak forcing and shallow
nature of the moisture. Breezy winds will continue across the
mountains as well. Lows will be 5 to 10 degrees below normal.
Heights begin to slowly rise Sunday as the channeled short wave
moves east. Expect some rebound in temps and across NE GA and the
Upstate while temps across NC remain nearly steady. Expect breezy to
windy conditions to develop as deep mixing taps some higher winds
moving in with the short wave. This mixing will also tap drier air
leading to very low RH values. See fire weather discussion for
details.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 200 PM Saturday: The back end of the upper trough will
continue to push offshore during the beginning portions of the
short term. Higher heights will increase during the early part
of next week as an upper ridge builds in from the west. Broad
Canadian high will control the overall weather during the period
as it sets up shop over the Carolinas and very gradually pushes
just off the Carolina coastline by Tuesday. A slight wind shift
will be in store as a light return flow from the S/SW works into
the region by Tuesday as the sfc high moves offshore. One forecast
concern will be the RH values across the region as dewpoints remain
in the 10s and 20s for a good chunk of the short term. This will
prog fire weather concerns, which will be provided in greater detail
in the Fire Weather discussion. Min T`s will remain below-normal
Sunday night, but rebound to near-normal Monday night. A similar
trend occurs with Max T`s as near-normal values will be likely on
Monday, while jumping ~5+ degrees on Tuesday.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 250 pm Saturday: Dry weather will continue with heights
building over the Eastern US Tuesday night into Wednesday due to the
subtropical ridge strengthening in the Gulf of Mexico. Thursday into
Friday high pressure will start to slide off into the western
Atlantic; however, the southwestern periphery of the ridge will
continue to extend into the Carolinas and NE Georgia. This pattern
will lead to above normal high temps early next week becoming well
above normal middle to late week. Friday into Saturday a cold front
could bring rain chances back into the forecast. Model guidance is
not in agreement in regards to the arrival of the cold front and its
associated moisture. Currently the ECMWF and Canadian have the front
pushing into the area Friday while the GFS has the front well to our
west for most of the weekend. Due to low confidence on the timing of
this front, we have kept a slight chance for rain across far western
NC for Friday. Saturday we introduced a slight chance of rain for
much of the forecast area. We will continue to monitor the
progression of this pattern in the coming days.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
At KCLT and elsewhere: VFR through the period at the TAF sites. Low
clouds moving south and east of the area as a short wave moves out
of the area. Expect clear skies across the area by sundown. Winds
will remain N to NW for the NC sites this afternoon, with low end
gusts at KAVL, and SW for the SC sites. Winds turn back to N to NE
overnight then pick back up from the N to NW, with stronger gusts at
KAVL, on Sunday. Can`t rule out some low VFR clouds across the
mountains late tonight into early Sunday, but should remain NE of
KAVL.
Outlook: Dry high pressure will remain in control well into next
week with VFR conditions prevailing.
Confidence Table...
00-06Z 06-12Z 12-18Z 18-00Z
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...
A very dry day expected Sunday as deep mixing and a dry air mass
lead to minimum RH values in the 15-25% range across the entire
forecast area during the afternoon. Elevated mountain winds,
generally 15-20 mph with higher gusts are expected as well. After
coordination with the USFS in Asheville, will issue a Fire Danger
Statement for the NC mountains. NE GA will likely need one as well.
However, after coordination with FFC, will hold off on issuance
until the morning to avoid confusion, as they are uncertain how much
of central and southern GA will be covered. Coordination may be
needed with NCFS for the foothills and Piedmont where winds won`t be
as strong but RH will be very low.
Monday will be warmer with even drier RH values. Winds won`t be as
strong, so statements not as likely over NC, but NE GA will likely
need another statement.
Moisture recovers some Tuesday, but low RH will again be possible
with NE GA likely the main location for fire danger with winds
relatively light once again.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Fire Danger Statement from Sunday afternoon through Sunday
evening for NCZ033-048>053-058-059-062>065.
SC...None.
&&
$$
SYNOPSIS...AP
NEAR TERM...RWH
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...RWH
FIRE WEATHER...RWH