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fxus63 keax 181659 
afdeax 


Area forecast discussion 
National Weather Service Kansas City/Pleasant Hill MO 
1159 am CDT Friday Jul 18 2008 


Updated aviation discussion... 


Discussion... 


Forecast challenges this morning deal with 
thunderstorm and heavy rain chances through Saturday afternoon...and 
then the building heat into early next week. 


Early this morning...a series of decaying convective complexes 
stretches from Kansas through Iowa...located within a band of deep 
subtropical moisture along the southern end of the westerlies. 
Persistent rain and embedded thunder over eastern Kansas and 
extreme northwest MO will likely make little additional eastward 
advancement this morning as upper ridging and sharply drier middle 
level air per gpsmet observations continue to block this activity. 


Continued middle-upper level moistening will gradually send 
precipitable water values to around two inches tonight...eliminating 
the cap at the expense of rather poor lapse rates. While 
redevelopment this afternoon and tonight is almost a given with no 
inhibition...placement and longevity of deep moist convection remain 
the key questions. Weak...but sufficient low level convergence will 
likely focus along primary surface front across neb/IA...as well as 
along early morning outflow boundary analyzed over northern MO. An 
embedded mesoscale convective vortex circulation is likely embedded in the remnants of the 
strongest mesoscale convective system...now near Hays Kansas...and may provide additional ascent 
during the afternoon/evening hours as this feature drifts eastward. 
Thus will continue with highest probability of precipitation along the Iowa border...dropping 
off quickly to the south. Heavy rainfall certainly possible given 
the thermodynamic profile and precipitable water forecasts...but high ffg 
values due to the recent overall dry spell do not warrant any watch 
headlines at this time. 


Threat for convection will slowly shift northward tomorrow as heat 
ridge builds eastward across the plains. Lingering morning 
convection may refire one last time Sat afternoon along any remnant 
boundaries...but main story by then will be the expected heat on 
Sunday. Models continue to depict some rather toasty 850mb 
temperatures...pushing into the middle 20s c beneath 592dm ridge. Should see 
hottest maximum temperatures of the year Sunday with highs in the middle 90s over 
much of the area and heat indices into the lower 100s. 


Bookbinder 


&& 


Aviation... 


A tropical plume continues to stream NE of the terminals ahead of an 
mesoscale convective vortex over eastern Kansas. Extensive cloud cover will limit instability through 
Saturday morning with mainly VFR occasional showers through the period. 
Brief periods of MVFR ceilings and fog are possible around daybreak. 


Db 


&& 


Eax watches/warnings/advisories... 
MO...none. 
Kansas...none. 
$$