Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 241736

1236 PM CDT Thu Jul 24 2014

Issued at 1235 PM CDT Thu Jul 24 2014

Forecast on track with only minor tweaks made. No need for an
update other than to remove previous morning wording.



.SHORT TERM:  (Through Late This Afternoon)
Issued at 333 AM CDT Thu Jul 24 2014

Surface ridge will remain overhead today with mostly sunny skies,
lower dewpts and cooler temperatures. Highs will only be in the
upper 70s to low 80s.


.LONG TERM:  (Tonight through Wednesday)
Issued at 333 AM CDT Thu Jul 24 2014

By tonight, surface ridge begins to move off to the east allowing
southerly winds and low level moisture to return once again. Models
continue to develop a complex over Iowa on nose of low level jet
with southern edge just skimming far northern portions of forecast
area after 06z Friday. Kept slight chance pops there for now.
Otherwise, dry conditions to prevail with lows in the upper 50s to
low 60s.

On Friday, complex to slide southeast across IL with northeastern
portions of forecast area on periphery of complex. Depending on
coverage of activity and cloud cover associated with it,
temperatures are hard to pin down. For now have highs ranging from
the low 80s far east to the low 90s over central MO.

By Friday night, main cold front to begin sliding southeast through
forecast area. With increasing low level jet once again and
increasing moisture, will see activity fire on nose of low level
jet along and east of Mississippi River. Will also see milder overnight
temperatures with lows only in the upper 60s to mid 70s.

Despite 850 temps between 22 and 24C, high temperature forecast will
be tricky on Saturday. With ongoing storms possible along frontal
boundary that will be moving through, could see a wide range of high
temperatures. For now kept forecast area rather warm with highs in
the low to mid 90s, and with dewpts in the low 70s, heat indicies
will approach 100 in many locations. Another issue will be the
possibility of severe weather especially Saturday afternoon and
Saturday night. High CAPES, plenty of low level moisture, and
shortwave tracking along boundary, could see complex develop and
slide east. SPC has put most of forecast area in a slight risk for
Day 3.

Frontal boundary and storms to finally exit region by late Sunday
with surface ridge building in for the first part of the work week.
Highs Monday through Wednesday will be in the upper 70s to low 80s.



.AVIATION:  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1235 PM CDT Thu Jul 24 2014

VFR conditions will prevail at the TAF sites thru the valid
period. A minor question of steam fog potential at SUS and perhaps
CPS due to unusual cool temps versus relatively warm river temps,
but airmass itself is quite dry and should inhibit this to some
degree and for now have not placed in the TAFs although if I did,
it would be more as VCFG than any direct impact. Otherwise look
for variable winds due to proximity of surface ridge to become SE
and S heading into Friday.

Specifics for KSTL: VFR thru the period with veering surface winds
to S by Friday.





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