Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 052029

329 PM CDT MON OCT 5 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 328 PM CDT Mon Oct 5 2015

Skies will turn mostly cloudy again tonight as a large stream of mid-
high clouds ahead of shortwave seen in water vapor imagery currently
over the Central Plains will move across the area.  Expect little if
any rain from this system as ascent and low level moisture is
lacking.  Lows tonight will be closers to the warmer GFS MOS because
of the clouds.


.LONG TERM:  (Tuesday through Next Monday)
Issued at 328 PM CDT Mon Oct 5 2015

(Tuesday through Thursday)

Clouds will linger throughout the morning on Tuesday before the
shortwave finally moves off to the east.  Then a ridge will build
over the area on Wednesday keeping dry weather going.  Then expect
scattered showers and thunderstorms to move into the area on
Thursday and Thursday night as both the GFS and the NAM show a upper
trough and an attendant cold front moving southeastward across the
Midwest.  Temperatures will warm up into the 70s and lower 80s as
850mb temperatures climb into the 10-15C range.

(Friday through Monday)

GFS and ECMWF are still in good agreement that the trough and cold
front will move east of the area early in the day on Friday which
will confine rain chances to the southeastern half of the CWA.  Then
both models show a surface high moving across the area on Saturday
before the low level flow turns southwesterly on Sunday ahead of the
next cold front.  Neither model is show any significant upper
troughs or depicting any QPF over the area during the Saturday
through Monday timeframe, so will go with a dry forecast for now.
Guidance temperatures support highs in the upper 60s behind the
front on Friday...but then gradual warming to around 80 by early
next week as 850mb temperatures climb into the upper teens Celsius.



.AVIATION:  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1251 PM CDT Mon Oct 5 2015

The region is void of any real atmospheric features so the trapped
low level moisture is not going anywhere anytime soon. The IFR
stratus has been slow to dsspt this morning with most sites finally
bcmng MVFR early this aftn. The E to W trend of the roding stratus
should continue thru the aftn and am optimistic that most if not
all sites will be VFR by 21Z. The thinking is that the existing
stratus late this aftn will have an impact on redvlpmnt overnight
along the edges. So depending how far W the ern edge can erode
this aftn will help determine what areas see VFR/MVFR CIGs/VSBYs
again tonight.

Specifics for KSTL:

Stratus finally dssptd with the 18Z ob...though there may be a few
short prds of MVFR CIGs prior to 20Z as the last of the stratus
burns off. The proximity of the reminder of the stratus by late
this aftn will play a role in whether IFR/MVFR stratus redvlps
tonight or not and it is too early to know where the ern edge will
end up. In areas where the stratus does not redvlp...fog is a
potential but mid/high clouds may limit dvlpmnt of IFR/MVFR VSBYs.





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