Flash Flood Warning 10, NWS St. Louis, MO

802 
WGUS73 KLSX 140745
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
245 AM CDT Tue May 14 2024

MOC027-139-151-140755-
/O.EXP.KLSX.FF.W.0010.000000T0000Z-240514T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Callaway MO-Montgomery MO-Osage MO-
245 AM CDT Tue May 14 2024

...FLASH FLOOD WARNING HAS EXPIRED FOR EAST CENTRAL CALLAWAY AND 
NORTHEASTERN OSAGE COUNTIES IN CENTRAL MISSOURI AND WESTERN 
MONTGOMERY COUNTY IN EAST CENTRAL MISSOURI...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

&&

LAT...LON 3879 9165 3879 9160 3872 9164 3864 9172
      3858 9179 3861 9181 3872 9177 3877 9170

$$

Britt

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
619 PM CDT Mon May 13 2024

.KEY MESSAGES...

- A slow-moving upper trough will bring waves of showers and
  scattered thunderstorms to the region through Tuesday
  afternoon. An isolated strong storm with gusty winds and small
  hail remains possible through this evening, mainly from central
  into southeast Missouri.

- After Tuesday evening, shower and thunderstorm chances will
  return late Wednesday through Friday.

- Above normal temperatures will return for the upcoming weekend.

&&

.SHORT TERM...  (Through Late Tuesday Night)
Issued at 225 PM CDT Mon May 13 2024

A slow-moving upper trof and low will produce unsettled weather
across the region through Tuesday evening as it progresses
eastward into and through the Mississippi Valley. A series of vort
maxes rotating through the trof along with diurnal heating will
modulate the greatest precipitation chances and coverage during
this time frame, however lesser precipitation chances will exist
the entire duration.

The first better defined vort max will rotate northeast across the
CWA the remainder of this afternoon into early evening bringing a
better organized band/wave of showers and some thunder. Thus far
thunder has been at a minimum. Despite areas of weak surface-
based CAPE of generally 1000+ J/KG, weak lapse rates and a good
deal of low-mid level moisture have diminished MLCAPE, which
seems to be a limiting factor thus far. There is a low chance of a
strong storm through early evening, primarily across central and
southeast MO, owing to slightly better deep layer shear, however
the moist conditions and low DCAPE are not very favorable. There
should diminishing coverage of precipitation to more scattered
later this evening and overnight with an additional vort max
tracking eastward providing some impetus. The moist low-levels and
light winds are also a recipe for fog/stratus.

The vertically stacked system and surface front will slide to the
east on Tuesday and into the eastern Ohio Valley by early evening.
Muted diurnal heating from breaks in the cloud cover should lead
to an uptick in instability and the coverage of showers and some
thunder on Tuesday afternoon. Precipitation chances should wind
down on Tuesday evening as the upper trof continues to progress
east into the Ohio Valley, potentially with fog/stratus in it's
wake into Wednesday morning.

Glass

&&

.LONG TERM...  (Wednesday through Next Monday)
Issued at 225 PM CDT Mon May 13 2024

An elongated and progressive northern stream upper trof will
bring the next organized chance of showers and thunderstorms in
the late Wednesday through Friday time frame. Differences in
position and timing of short waves moving through the mean upper
trof are resulting in probably a longer window of precipitation
chances in the forecast than reality. The initial chance of
showers and storms could as early as Wednesday night depending on
the position of a lead vort max and forcing via a southwesterly
LLJ along with a returning warm front. There is better agreement
that the chance of showers and thunderstorms will peak Thursday
morning through the afternoon into early evening along and ahead
of an advancing cold front.

A southern stream upper trof could linger the rain chances longer
into Friday or early Saturday but there is a decent amount of
spread in the specifics of the trof speed/structure with the LREF
cluster analysis showing four variations in the larger scale flow,
and thus lower predictability. It does appear we should see
temperatures return to above normal for the upcoming weekend with
the NBM showing the entire IQR above normal.

Glass

&&

.AVIATION...  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 617 PM CDT Mon May 13 2024

Multiple rounds of showers and thunderstorms will rotate through
the region over the coming 12 to 24 hours. Timing each round is a
bit uncertain, so future updates may be needed. Thunder is more
likely this afternoon with that threat decreasing this evening.
Areas of MVFR ceilings are also accompanying these showers, but
pockets of VFR can be seen in between. Expect broader MVFR to IFR
conditions becoming widespread overnight tonight into the day on
Tuesday.

Kimble

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

WFO LSX

Hazardous Weather Outlook
National Weather Service St Louis MO
244 PM CDT Mon May 13 2024

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-141945-
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL-
Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair IL-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
244 PM CDT Mon May 13 2024

This Hazardous Weather Outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Tonight.

There is a low chance of thunderstorms tonight. An isolated strong
thunderstorm with gusty winds and small hail is possible through this
evening.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

There is a chance of thunderstorms Tuesday and Tuesday evening, Wednesday
night through late Friday, and Saturday afternoon through Sunday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Glass