Area Forecast Discussion
Issued by NWS St. Louis, MO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KLSX 061129

629 AM CDT TUE OCT 6 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 350 AM CDT Tue Oct 6 2015

Scattered sprinkles/light rain showers have developed over
northwestern MO early this morning ahead of a weak vort max in
northeastern KS. The area with light sprinkles also coincided with
an area of moisture convergence between H8-H7 as well as a pocket of
steeper lapse rates. A few sprinkles or light rain showers could
move into central or northeastern MO this morning.

The slow warming trend continues today with afternoon highs expected
to be a few degrees warmer than yesterday. This should lead to highs
in the 70s across most of the area, although a few sites in
southeastern MO and/or southwestern IL could reach the lower 80s
depending on how quickly the clouds clear out.


.LONG TERM:  (Tonight through Monday)
Issued at 350 AM CDT Tue Oct 6 2015

Forecast trends will remain essentially unchanged in this
forecast package: dry and mild weather is expected tonight and
into Wednesday, followed by a chance of showers and thunderstorms
in the Thursday-Friday time frame as upper level shortwave and
trof and associated cold front work their way across the
Mississippi Valley. The only real change in the forecast was a
slight slowing of the southward progression of PoPs across the
area, as all of the 00z guidance was just a bit slower with the
shortwave and cold front than earlier solutions. The slower
solutions also dovetails with the idea of holding onto low chance
PoPs over southern sections of the CWA on Friday. Have decided to
maintain highest PoPs for this event at around 50% for
now...although MET and MAV are considerably lower operational
ECMWF-based MOS guidance is indicating likely PoPs in many areas
with the fropa. Additional adjustments to PoPs will probably be
necessary with time as the details become a bit more clear.

Daytime highs will be above average on Wednesday and Thursday with
highs in the middle 70s to lower 80s.  However, temperatures will be
dipping below seasonal norms by Friday, as the post-frontal cool-
down shaves some 10-15 degrees off of max temps.

Medium range solutions are still indicating that this cool down will
be brief, as the progressive UA regime across the CONUS allows a
strong ridge to build back into the nations`s midsection for the
start of next week.  Guidance is suggesting 850MB temps of at least
16-18C on Monday, which would certainly support highs back in the
80s over most of the CWA. Lack of moisture and any significant
dynamics/lift suggest dry weather will accompany this warmup.



.AVIATION:  (For the 12z TAFs through 12z Wednesday Morning)
Issued at 618 AM CDT Tue Oct 6 2015

Specifics for KUIN, KCOU: Scattered sprinkles have developed near
KCOU and KUIN early this morning ahead of a weak disturbance. It`s
possible that a stray shower could reach one of these TAF sites.
Satellite and METARs also depicted a few areas of MVFR stratus
near KUIN, which should lift to VFR later this morning. Otherwise
VFR conditions with light northerly winds are expected for the
remainder of the TAF period.

Specifics for KSTL, KSUS, KCPS: Light fog has developed early this
morning but should dissipate by 14-16z. VFR conditions with light
northerly winds are expected for the remainder of the TAF period.





WFO LSX is the U.S. government's official web portal to all federal, state and local government web resources and services.