186
FXUS63 KPAH 261150
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
650 AM CDT Thu Sep 26 2024

.KEY MESSAGES...

- Clouds will increase from the east this afternoon and evening.
  A chance of showers and thunderstorms will also spread west
  through the afternoon and evening.

- Widespread showers with heavy rain will set in after midnight
  tonight and continue through Friday evening, as the remnants
  of Hurricane Helene interact with an upper-level storm system
  near the Quad State. Forecast rainfall in this period
  currently ranges from around 2 inches along I-64 to 3-4 inches
  over much of west Kentucky and adjacent portions of southern
  Illinois and southeast Missouri.

- The rains will become lighter and more isolated through the
  weekend.

- The Quad State will begin to dry out on Tuesday as a cold
  front passes. Highs in the 70s and lows in the 50s are
  expected Tuesday through next Thursday.

&&

.DISCUSSION...
Issued at 323 AM CDT Thu Sep 26 2024

Much of the region will see quite a bit of sunshine today, with
clouds increasing from the east through the afternoon. Scattered
showers and thunderstorms will also spread west to the
Mississippi River by sunset. The scattered convection will
continue to spread west through southeast Missouri in the
evening, as more widespread rain begins in the east.

The most widespread and heavy rains are still expected from
late tonight through Friday evening, when WPC QPF ranges from
around 2" along I-64, to 3-4" over much of west Kentucky and
adjacent portions of southern Illinois and southeast Missouri.
There has been a bit of a shift to the north with the heavier
rains with this forecast cycle. In general, with the dry soil
across the Quad State, this amount of rain should not cause
significant flooding issues. A Flood Watch was discussed, but
confidence is too low to issue one for the third and fourth
periods of the forecast.

WPC QPF still seems overdone. All of the concerns we outlined
yesterday remain this morning. The GFS and ECWMF ensembles still
hammer on extremely anomalous moisture in the mid and high
levels, but have hardly a blip in the low-levels. Presumably,
much of the tropical air mass will be rained out to the east of
the Appalachians. The 00Z GFS and ECMWF ensembles have a high
probability of reaching 2+" over southern portions of the
region, but have a very low probability of 4+". Would feel
better with a general 2-3" QPF for our area.

As for wind gusts, the 00Z ECWMF ensembles have greater than a
50% chance of reaching 35kts or more over the Evansville Tri
State, much of southern Illinois, and even northern portions of
southeast Missouri Friday afternoon and night. This is a
significant increase from yesterday`s ensembles. With widespread
cloud cover and precipitation it will be difficult to mix down
the stronger winds to the ground. Also, confidence in how the
tropical circulation will be impacted by the Appalachians
remains quite low. We may very well need a Wind Advisory, but
confidence will continue to be low until Friday morning when
the circulation is expected to emerge on our side of the
mountains.

Guidance is shifting the merged storm system to the east faster
than previously forecast. That will hopefully result in a
shorter duration of rainfall over the Quad State. QPF for
Saturday and Sunday is generally a half inch or less with most
of that falling on Saturday. WPC has no QPF after sunset on
Sunday. The NBM hangs onto some small chance PoPs for Monday,
but it may not amount to anything.

Guidance has diverged for next week, with the upper flow
possibilities ranging from southwest to west to northwest. The
bottom line is that the cool down advertised yesterday may not
happen at all. At least, the forecast Tuesday through next
Thursday is dry.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 650 AM CDT Thu Sep 26 2024

Northeast winds will increase through the period. Some 15-20kt
gusts will be possible this afternoon, and by the overnight
hours winds will be sustained 15-20kts with gusts 20-30kts.
Initial VFR conditions will gradually worsen from west to east
from mid-afternoon through the end of the period. Ceilings will
gradually lower to IFR levels by the end of the period, and
visibilities will drop to MVFR levels in rain overnight.

&&

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

&&

$$

DISCUSSION...DRS
AVIATION...DRS