Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 231119

619 AM CDT Sat Aug 23 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 332 AM CDT Sat Aug 23 2014

Warm frontal boundary remains across region early this morning
with isolated/scattered storms firing north of it. A few have
moved into far northern portions of forecast area early this
morning. So have added isolated mention in this area through 15z
today. Otherwise, summer has returned with a vengeance with
dangerous heat and humidity. Because of the high dewpts in the
upper 60s to mid 70s, lowered high temps a degree or two for
today. This will not affect heat indices as the higher dewpts and
slightly lower highs still create indices in the 100 to 109 degree
range once again. High resolution models want to generate
thunderstorm activity mainly east of Mississippi River this
afternoon but feel it will just skim our far eastern portions, so
added slight chance pops in this area.


.LONG TERM:  (Tonight through Friday)
Issued at 332 AM CDT Sat Aug 23 2014

Models are keeping boundary draped across forecast area through
at least this evening before it weakens and lifts north late tonight.
So with front north of area on Sunday, it could be our hottest day
with temps approaching 100 for southern half of forecast area.
Heat indicies will once again be between 100 and 109. Will remain
hot through at least Monday, so will keep advisories and warnings
going through that period.

Still not confident on exact timing with next weather system, which
could begin to bring some rain to region by Tuesday, but just a
slight chance. Could see hot enough temps and heat indices on
Tuesday to keep headlines through then, but not confident enough to
do that at this time. Otherwise, will see better chances of rain
Wednesday through Thursday with temperatures cooling off.



.AVIATION:  (For the 12z TAFs through 12z Sunday Morning)
Issued at 613 AM CDT Sat Aug 23 2014

Weak boundary should continue to lift north today with best
chances of any precipitation remaining north and east of
terminals. Upper level ridge in place will provide another hot and
humid day. Light and variable wind early this morning will become

Specifics for KSTL:

VFR conditions expected as convection should remain well north and
east of the terminal thanks to an upper level ridge. The light and
variable wind this morning will become south-southwest today.



MO...HEAT ADVISORY until 7 PM CDT Monday FOR Audrain MO-Boone MO-
     Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Jefferson MO-Knox MO-Lewis MO-Lincoln MO-Madison MO-
     Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike
     MO-Ralls MO-Reynolds MO-Shelby MO-St. Charles MO-St.
     Francois MO-Ste. Genevieve MO-Warren MO-Washington MO.

     EXCESSIVE HEAT WARNING until 7 PM CDT Monday FOR St. Louis City
     MO-St. Louis MO.

IL...HEAT ADVISORY until 7 PM CDT Monday FOR Adams IL-Bond IL-Brown
     IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Marion IL-Monroe IL-Montgomery IL-Pike IL-
     Randolph IL-Washington IL.

     EXCESSIVE HEAT WARNING until 7 PM CDT Monday FOR Madison IL-St.
     Clair IL.



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