Scientific Forecaster Discussion
fxus62 kgsp 142153
Area forecast discussion
National Weather Service Greenville-Spartanburg SC
553 PM EDT Mon Oct 14 2019
moisture and rain chances return to the region later on Tuesday
ahead of a complex frontal system. In the wake of this system, dry
air punches back into area later Wednesday with a cooler northwest
flow of air expected for Thursday and Friday.
Near term /through Tuesday/...
as of 550 pm: minor adjustments made to temperatures/dewpoints to
coincide with current trends, as the rest of the near term forecast
remains well on track.
Otherwise, northerly flow will continue to dry out the atmosphere
through the evening, resulting in clear skies, which should last
through the bulk of the overnight, before mid and high level clouds
increase from the southwest toward daybreak. This will likely result
in the coolest night of the season so far in many areas. Of some
concern is that some of the sheltered valleys along the Tennessee border
saw min temps as cool as the mid-30s this morning, and this looks
entirely possible again tomorrow morning, but it does not appear
frosty temps will be widespread enough to warrant advisory
Heights will begin falling across the eastern conus by the end of
Tuesday, and this is forecast to instigate activation of the
baroclinic zone near the Gulf Coast by tomorrow afternoon. The
northern edge of the precip shield is expected to make a run for the
upper Savannah River valley/lakelands region by the end of the
period, and likely-to-categorical pops are advertised there early
Tuesday evening. For the remainder of the area, Tuesday will be dry
and seasonably warm. Temps are expected to average right around
climo, except across our southwest zones, where thicker cloud cover
will reduce insolation, likely holding maxes a category or so below
Short term /Tuesday night through Thursday/...
as of 2:25 PM monday: the short-term forecast picks up at 00z
on Wednesday with another upper trof digging down across the
northern plains and moving towards the Ohio River valley. The
trof is expected to amplify as it approaches our area, with the
trof axis passing just to our north by late Wednesday. The main
trof axis then lifts NE and offshore on Thursday as a weaker,
secondary trof axis dives down the backside of the main trof
towards the very end of the period late Thursday.
At the sfc, the next round of deep, pre-frontal moisture will
be spreading over the fcst area from the southwest as the period
begins late Tuesday. Overall, the models continue to trend a bit
slower wrt the spread of the deep moisture into the cwfa, with
pops not reaching likely values across the bulk of the County warning forecast area until
just after 00z Wed. Most of the quantitative precipitation forecast is still expected to fall
between roughly 00 and 12z, with storm total amounts now less
than 1 inch across most of the County warning forecast area. The cold front will push
thru the fcst area Wednesday morning and move off the coast
Wed night. In its wake, drier and much cooler high pressure
will spread over the region and linger into the extended period.
Although temps Thursday morning across the higher terrain might
be cold enough to support frost, it's looking like winds will
be too gusty for much if any frost development. Otherwise, temps
start out above climatology on Wed and drop at least a category
below climo for thurs.
Long term /Thursday night through Monday/...
as of 2:15 PM monday: the extended forecast picks up at 00z on
Friday with a weaker, secondary trof axis moving over the fcst
area. This feature should move off the Atlantic coast by late
Friday with heights recovering in its wake. Upper ridging will
then spread back over the region on Saturday and linger into
early next week. At the sfc, dry high pressure will be centered
just to our north by early Friday. The high will linger over the
region into the weekend and begin to drift offshore by late Sat
allowing more moist southerly flow to gradually spread back over the
County warning forecast area on Sunday. By early next week, another cold front will be
approaching the fcst area from the west. The period will remain
dry thru Saturday with pops ramping up on Sunday and Monday.
The main concern will be the potential for frost across the
higher terrain early Friday as temps could be cold enough and
winds are expected to be light. The best chances for frost will
be over the northern mtns. Otherwise, temps rebound thru the
period, with highs reaching the mid to upper 70s across the
non-mtn zones over the weekend.
Aviation /22z Monday through Saturday/...
at kclt and elsewhere: with northerly winds pushing drier air into
the terminal forecast area, VFR conditions are expected to persist
through the period, with only increasing (mainly) high clouds
expected tomorrow morning. Some stratocu on the lower end of the VFR
may develop at kand near the end of the period, as moisture begins
increasing again from the southwest, while fog and/or low stratus
will probably develop in the valleys of far southwest NC late
tonight. But again, all taf sites, including kavl should remain
Outlook: rain with associated flight restrictions is expected at
times along and ahead of a cold front late tues thru Wed afternoon.
Gusty northwest winds are expected behind the cold front late Wed
into Thu. Drier conditions return for the end of the week.
22-04z 04-10z 10-16z 16-18z
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 and ensemble forecasts
are available at the following link: