Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 260824

324 AM CDT Tue Aug 26 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 323 AM CDT Tue Aug 26 2014

Frontal boundary beginning to make its way south towards forecast
area today. Main issues today will be cloud cover, precipitation
and how this affects temperatures/heat indices. For now feel that
activity will be isolated/scattered in nature today, especially
during the afternoon hours. So there should be enough sunshine for
temperatures to rise into the mid to upper 90s once again, with
low 90s in the far north closer to the boundary. Even though
frontal boundary to eventually wash out along I-70 corridor late
this afternoon, dewpts to pool along this boundary keeping heat
indices in the 100 to 110 degree range, so headlines to remain
through 01z Wednesday.


.LONG TERM:  (Tonight through Monday)
Issued at 323 AM CDT Tue Aug 26 2014

Some question tonight on low temperatures. Guidance is a bit too low
so went a few degrees above for overnight lows as dewpts remain in
the low 70s most locations. Keep pops going everywhere early this
evening as diurnal activity to linger a bit past 00z Wednesday, then
activity refocuses back to the north on nose of LLJ later tonight.

Will see a series of shortwaves slide east northeast through
region Wednesday through Friday, with best chances of storms over
northern half of cwa through Friday. Highs on Wednesday will be in
the upper 80s to mid 90s, so could see heat indices near 100 once
again. So depending on cloud cover, precipitation and dewpts, may
have to extend heat headlines a bit longer, but will leave as is
for now.

Then main weather system to slide through region beginning Friday
night with best chances of rain Saturday and Saturday night.

Temperatures to slowly lower through the rest of the forecast
period, eventually highs will only be in the 80s by the weekend and
into early next week.


.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1142 PM CDT Mon Aug 25 2014

Weak SFC front stretches from NE KS thru NW MO and on into ern
IA. This bndry is expected to slowly sag south thru the prd
reaching the I70 corridor by Tuesday evng. There is a chance for
convection along the front with the best chances/coverage near the
KUIN terminal. Due to continued uncertainties about coverage and
placement...have not included a VCTS group in this package and
will let later shifts reassess the threat.

Specifics for KSTL:

Weak bndry is fcst to approach the terminal tomorrow aftn allowing
winds to become erly by evng. There is a threat for convection...but
low confidence in coverage and placement preclude inclusion attm.
Winds have remained 8-10 kts this evng and not sure no
other metro site has had winds that strong and guidance doesn`t
support it hesitant to go much above 6 or 7 kts
overnight with the thinking that they will subside some shortly.


MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Knox MO-Lewis MO-Madison MO-Marion MO-Moniteau MO-
     Monroe MO-Montgomery MO-Osage MO-Ralls MO-Reynolds MO-
     Shelby MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-Pike MO-St. Charles MO-St. Louis City MO-St.
     Louis MO.

IL...HEAT ADVISORY until 8 PM CDT this evening FOR Adams IL-Brown IL.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Pike IL-Randolph IL-St. Clair IL-Washington IL.


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