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fxus63 klsx 051031 
afdlsx 


Area forecast discussion...updated aviation 
National Weather Service St Louis MO 
531 am CDT Sat Jul 5 2008 


Discussion... 
/247 am CDT Sat Jul 5 2008/ 
main concern is rain chances into early next week. Generally 
followed the ecwmf which lines up well overall with the other global 
models without the convective feedback that the GFS has. 


Will likely keep some mention of patchy fog going through early this 
morning over S central Illinois into southeastern MO where surface observation are showing 
some sites with visibilities at or below 1sm. Should start the 
morning mostly clear which should allow it to burn off pretty 
quickly. 


Expect dry weather through late tonight as atmosphere will be 
relatively stable. Forecast soundings are showing MUCAPES climbing 
to around 1000 j/kg with relatively little cinh with parcels 
orginating around 850mb. There will be some meager low level 
925-850mb moisture convergence along retreating warm front...so 
have some slight chance probability of precipitation over central and southeastern MO. Have kept 
slight chances going into Sunday as atmosphere becomes 
increasingly unstable with MLCAPES climbing above 2000 j/kg...but 
models depict only weak convergence along the front and enough 
cinh to keep chances slight. Chances will increase into Monday and 
Tuesday as series of shortwave troughs moving across the northern Continental U.S. 
Will eventually help push a cold into the County Warning Area. Going probability of precipitation still 
look good given convergence along the front and available 
instability for it to act on. 


Looks like another below average day today with relatively light 
easterly winds. Temperatures then warm back to near or just above 
normal as warm front moves through and surface winds turn south to 
southwesterly for Sunday and Monday. Guidance temperatures are in 
great agreement and see no reason to stray from them. 


Britt 


&& 


Aviation... 
/518 am CDT Sat Jul 5 2008/ 
for the 12z tafs...light fog/haze has developed in stl/sus early this 
morning. This should dissipate rapidly by 9 am with full sunshine. 
Few-scattered diurnal cumulus clouds will develop lt this morning at the taf 
sites. These clouds should dissipate early this evening with loss of 
daytime heating. A light east-northeasterly surface wind will gradually veer around to a 
east-southeasterly direction by this afternoon or evening as the surface ridge extending from Michigan 
SW to eastern MO moves slowly eastward. 


Gks 


&& 


Lsx watches/warnings/advisories... 
MO...none. 
Illinois...none. 
&& 


$$ 


Weather forecast office lsx