434
FXUS63 KPAH 121841
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
141 PM CDT Thu Sep 12 2024

.KEY MESSAGES...

- The remnants of Tropical Depression Francine will impact the
  region this evening through the weekend. The steadiest
  rainfall will move through tonight while daily chances of
  scattered showers and storms persist Friday through at least
  Sunday. Total rainfall between 1 to 3 inches is expected. Wind
  gusts between 20 to 30 mph are also possible.

- More humid conditions can be expected Friday into the weekend
  with high temperatures about 5 degrees below normal in the
  upper 70s to lower 80s. Drier conditions return by the middle
  of next week, but a significant warm up near to slightly above
  normal looks likely by Thursday and Friday with highs back in
  the upper 80s to near 90.

&&

.DISCUSSION...
Issued at 139 PM CDT Thu Sep 12 2024

Sfc analysis shows Tropical Depression Francine located over central
Mississippi as the remnants will begin to impact the FA this evening
with heavy rainfall and gusty winds. The latest NHC advisory now
takes Francine into NE Arkansas by Friday morning when the center of
low pressure will become post tropical. Meanwhile, clouds continue
to thicken this afternoon as saturation in the low-levels of the
column will be slow to occur due to dewpoints still in the 50s.
MaxTs will range from the low to mid 80s.

Between 00-06z tonight, the outer rain bands will spread from south
to north as an axis of 850 mb frontogenesis rapidly causes the
column to saturate. Have PoPs turning "categorical" as this is when
the steadiest rainfall can be expected. Winds will also increase as
the pressure gradient tightens. Leaned above NBM guidance again for
wind gusts between 20-30 mph as the percentiles for 850 mb winds
above 50+ kts and SLP near 1008 mb in the FA are still supportive of
better mixing in the boundary layer.

By Friday, additional scattered showers and storms remain likely,
especially during the afternoon and evening hours as cyclonic flow
associated with a 500 mb low provides additional forcing for ascent.
Still not terribly concerned about the severe weather potential as
the better ingredients remain SE of the FA. It is worth noting other
model guidance has trended higher with dewpoints in the lower 70s
like previous runs of the NAM. For this reason, the RAP now shows a
swath of MLCAPE between 500-1000 J/kg developing over western
Kentucky in the afternoon to support scattered storms. Unlike Beryl
which had a lot more momentum, Francine will have a much weaker wind
field on Friday inhibiting the severe potential.

Overall, total QPF is now progged between 1.0-2.5 inches, with
locally 3.0 inches possible as the heavy rainfall potential
continues to shift south. Given the D1-D2 drought conditions,
flooding is not a concern other than localized runoff on roadways
with torrential tropical downpours. Daily scattered shower and storm
chances do linger over the weekend, with the highest PoPs progged
during the afternoon hours. While the humidity will be higher with
dewpoints near 70, maxTs will be about 5 degrees below normal
ranging from the upper 70s to lower 80s.

By next week, model guidance remains persistent in showing an omega
block pattern setting up as one closed 500 mb low will be over the
SE CONUS while another one will be located over the W CONUS. Cylonic
flow will keep pcpn chances in the forecast on Monday due to some
additional tropical moisture from the east with another possible
disturbance, but by Tuesday is progged to only be a "slight chance"
by the NBM as sfc high pressure located near New England builds into
the Ohio Valley. By the middle of next week, a ridge axis over the
central Plains will begin to build more east allowing for temps to
return to near to slightly above normal. In fact, a significant warm
up is looking likely as the LREF box & whisker plots range from the
mid 80s to near 90, especially on Thursday and Friday.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1145 AM CDT Thu Sep 12 2024

Clouds will thicken through the afternoon as the remnants of
Tropical Depression Francine move closer to the region from the
south. Conditions will remain VFR as it will take some time to
reach saturation in the column. East winds near 10 kts with a
few gusts around 16-17 kts are expected.

Between 01-06z tonight, SHRA will spread from north to south
across all terminals when the steadiest pcpn is progged. The
risk for TSRA still remains extremely low to include any TAF
mention. The main concern however will be MVFR/IFR cigs and
vsby reductions into Friday morning. An increase in the pressure
gradient will also mean more breezy conditions. East winds
between 10-16 kts with gusts around 20-25 kts are possible.

Lingering SHRA remains possible mainly at KPAH/KCGI after 13z
while drier conditions are expected across the northern
terminals. Towards the end of the TAF period, the risk for TSRA
does begin to increase, especially across western Kentucky. East
winds around 10 kts with gusts around 20 kts are possible.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.

&&

$$

DISCUSSION...DW
AVIATION...DW