Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 221126
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
626 AM CDT Fri Aug 22 2014

.SHORT TERM: (Through Sunday)
Issued at 312 AM CDT Fri Aug 22 2014

Well it finally feels like summer. Heat index values yesterday
afternoon topped out around 105 degrees in the immediate St. Louis
Metropolitan Area where the EXCESSIVE HEAT WARNING remains in
effect until Sunday evening. Elsewhere, heat indices remained
within the 100 to 104 degree range, including locations across
northeast Missouri and west central Illinois. Will be adding the
northeast Missouri and west central Illinois counties to the HEAT
ADVISORY to account for heat index values reaching longevity
criteria of 100 degree heat index for four or more days. I expect
that the longevity of the heat wave (now likely extending into
next week) will lead to future extensions in time as confidence
increases.

Have introduced some low chance POPs for thunderstorms this
afternoon and evening across the northern half of the CWA. Hard to
ignore mesoscale model guidance suggesting a secondary warm front
developing across the northern CWA by this evening as low pressure
deepens across the Central Plains. Both 00Z 4KM NCEP and NSSL WRF
runs depict an active late afternoon and evening across the northern
CWA - with the potential for an outflow to move south toward I-70.
Again, for now, I have only increased POPs so that there is a
mention in the forecast. Day shift will have to reevaluate as HRRR
and RAP comes into range later this morning.

CVKING

.LONG TERM: (Monday through Thursday)
Issued at 312 AM CDT Fri Aug 22 2014

Hot and dry conditions extend into next week ahead of a cold front
that is now forecast to arrive on Wednesday. This front should
bring a chance of rain and utlimately cooler temperatures by
Thursday.

CVKING
&&

.AVIATION:  (For the 12z TAFs through 12z Saturday Morning)
Issued at 626 AM CDT Fri Aug 22 2014

Complex of storms moving east across northern Missouri as of 11z.
For now have added vcts mention at KUIN through 15z. Otherwise,
rest of taf sites to remain dry with vfr conditions and light
winds picking up from the southwest this morning. Then winds to
become light and variable once again this evening. KUIN continues
to be on southern perifery of storm activity, so added vcts
mention after 01z Saturday.

Specifics for KSTL:
Metro area to remain dry with vfr conditions and light winds
picking up from the southwest this morning. Then winds to become
light and variable once again by 01z Saturday.

Byrd
&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 7 PM CDT Sunday FOR Audrain MO-Boone MO-
     Callaway MO-Cole MO-Franklin MO-Gasconade 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-Shelby
     MO-St. Charles MO-St. Francois MO-Ste. Genevieve MO-Warren
     MO.

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

IL...HEAT ADVISORY until 7 PM CDT Sunday 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 Sunday FOR Madison IL-St.
     Clair IL.

&&

$$
WFO LSX




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