967
FXUS63 KPAH 032343
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
Issued by National Weather Service Quad Cities IA IL
643 PM CDT Thu Apr 3 2025

.KEY MESSAGES...

- Multiple rounds of additional thunderstorms will result in
  historically high forecast rainfall amounts, totaling as much
  as one foot in places. Significant and widespread flooding
  will likely develop across the Quad State through Sunday.

- Additional rounds of severe storms are possible this afternoon
  and evening, Friday afternoon and evening, and Friday night
  into Saturday. The most significant threat will be over
  southeast Missouri Friday night.

- Cool/cold and mostly dry conditions are expected for the
  first half of next week.

&&

.DISCUSSION...
Issued at 230 PM CDT Thu Apr 3 2025

The multi-day exceptionally heavy rain and severe weather event
remains forecast for the region through Saturday night.

Through the day today, the surface warm front has remained well
south of the Quad State, with the 2 PM position laying out from
southern Arkansas to south central TN, through eastern KY. While
this southern position has kept our CWA from developing any
surface instability (a good thing), the upper flow continues
from the southwest over this front to the south. The result has
been wave after wave of elevated showers and thunderstorms
throughout the Quad State region. While most of this activity
has been quick moving, producing relatively light amounts, the
more persistent bands of showers and storms have brought some
areas of heavy rainfall, mainly in the southern counties.

Through the afternoon, increasing instability will advect
northeastward from Arkansas, where scattered intense cells are
already forming early this afternoon, many with supercellular
structure. I do not think we`re looking at the same threat,
given the lack of boundary layer instability, however this next
wave of storms will bring a more widespread heavy rain threat
into this evening and overnight. The Flood Watch and some
warnings remain in place, as that threat is ongoing.

Looking at the next 48+ hours, we will evolve from persistent
moisture advection( PWAT values over 1.75") over the surface
front due to a positively tilted upper trof to the west, and
strong upper jet streak to our north, to a more progressive,
highly forced surface low and upper trof passage Saturday night.
The result will be persistent showers and thunderstorms with
excessive rainfall each period through Saturday night. Rainfall
amounts remain forecast to be historically high, and impacts
could be catastrophic in some locations into Sunday. Even the
10% percentile NBM data supports 4-6 inches of rain, which is a
remarkably high statical signal for excessive rain. WPC
continues a moderate to high risk of excessive rain each day
through Saturday night.

Severe weather is less confident tonight into Friday morning,as
the numerous elevated storms and heavy rain continue. However,
Friday afternoon into Saturday evening, stronger winds aloft are
forecast to increase shear values to 50kts or above as the upper
trof to our west begins to evolve from positive tilt to more of
a negatively tilt position. Thus, winds aloft will begin to
strengthen and the surface boundary is expected to lift
northward into KY. Tornadoes, damaging winds, and very large
hail remain possible along and south of the surface boundary,
with main hail to the north, and locally damaging winds.

Saturday, it`s a bit hard to discern the position of the front
with confidence, as convection may greatly disturb the
environment. however the upper forcing is strong, and a severe
weather threat remains quite possible, especially in southern
areas, which will have greater instability in the boundary
layer.

Looking beyond this pattern, the upper flow will sweep much
colder air into the region for Sunday and early next week. Highs
in the 40s and 50s will bring a little early spring chill to the
air, but the overnight lows may need some eyes on them, as below
freezing temperatures appear possible Monday night and Tuesday
night! It seems like every period of this forecast has some
kind of hazard, be safe out there everyone!!

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 635 PM CDT Thu Apr 3 2025

Challenging set of TAFs with regards to timing of precipitation
and low cloud trends. In general, expecting waves of elevated
SHRA/TSRA tonight into Friday morning with lift atop a frontal
zone stalling out south/east of the terminals. Given the
periodic nature of the precipitation it makes for difficult
timing, and thus we have some larger periods of prevailing
mention with conditions mainly VFR to MVFR though pockets of IFR
(visibility) is possible. Will continue to monitor radar trends
and adjust as needed. The cooler east/northeast flow will also
allow for lower clouds to develop later tonight and Friday
morning with CIGs dropping into IFR and MVFR. A weakening
nocturnal LLJ and some increase in heights aloft may lead to
a decrease in coverage of precipitation by and after 18z. Winds
will be challenging as well. In general, anticipate winds
prevailing from the north/east tonight into Friday with some
localized gusts 15-20+ kt before veering more from the east and
south, as the front begins to lift northward bisecting the region.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Flood Watch through Sunday morning for ILZ075>078-080>094.
MO...Flood Watch through Sunday morning for MOZ076-086-087-100-
     107>112-114.
IN...Flood Watch through Sunday morning for INZ081-082-085>088.
KY...Flood Watch through Sunday morning for KYZ001>022.

&&

$$

DISCUSSION...DRS
AVIATION...WFO DVN