599 
fxus63 ksgf 232353 
afdsgf 


Area forecast discussion 
National Weather Service Springfield MO 
653 PM CDT Wednesday Jul 23 2008 


..update to aviation... 


Discussion... 


The area remains in northwest flow aloft as an upper level low is 
located over the Great Lakes region and an upper level ridge is 
located just to the west of the County Warning Area. A surface front is also 
located across the southern portions of the County Warning Area. Convection formed 
along this boundary overnight and pushed south out of the County Warning Area 
during the morning hours. 


Drier air aloft has moved into the eastern portions of the County Warning Area 
behind the frontal boundary...with 700-300mb relative humidity in the 10 to 20 
percent range. More moisture and instability is in place ahead of 
the front across southeast Kansas and extreme southwest Missouri. 
Early afternoon convective available potential energy were in the 1000 to 2000 j/kg range across 
these areas. As instability continues to increase today with the 
heating of the day...isolated to widely scattered thunderstorms 
will be possible along and south of the surface boundary...roughly 
south of Highway 60 and west of a Gainesville to Mountain Grove 
line. Wind shear will remain weak across these areas...which 
should limit the severe potential. With the limited wind shear the 
storms will be pulse in nature. This activity should begin to 
weaken shortly after sunset this evening. 


An mesoscale convective system is then expected to develop across southeastern South 
Dakota into northeastern Nebraska...and is expected to move to the 
southeast. This mesoscale convective system should push into central Missouri during the 
morning hours. Have included slight chances for thunderstorms 
across central Missouri overnight in case it develops farther 
south or has a faster movement...but feel the better chances 
will be during the day time hours tomorrow. Have increased probability of precipitation 
across the eastern County Warning Area to account for this activity. There will 
likely be multiple outflow boundaries from this activity that may 
be the focus for redevelopment during the afternoon and evening 
hours. The better dynamics will remain north of the area... 
therefore the severe potential should be limited across the 
County Warning Area. However cannot rule out a few storms capable of producing 
damaging winds. Have lowered temperatures across the eastern County Warning Area 
on Thursday into the lower to middle 80s. 


The upper level ridge will nudge into western Missouri on 
Thursday...which should push the storm track farther to the 
north and east into next week. Nightly mesoscale convective system should develop in the 
northwest flow north of the County Warning Area and push to the south and east. 
Current thinking is that the best chances for showers and 
thunderstorms will be across the far north and eastern portions of 
the County Warning Area. Will have to monitor the outflow boundaries from these 
mesoscale convective system...in case they drift into the western County Warning Area. They could become the 
focus for afternoon thunderstorms as instability increases with the 
heating of the day in these areas. 


Wise 




&& 


Aviation... 


Isolated thunderstorms continue to develop along residual outflow 
boundaries from previous thunderstorms in southwest Missouri near 
kjln. Based upon radar and satellite trends...have opted to go 
with vicinity thunderstorms at kjln. Due to light winds and 
remnant cloud cover from dissipating thunderstorms near 
kjln...haze has been included in the taf during the short term. 
After sunset...isolated thunderstorm development will cease. 


Thunderstorm development near ksgf is not expected until possibly 
early Thursday morning into the afternoon. Overnight...will 
monitor the development of convection in Nebraska and Iowa. A 
complex of thunderstorms could move into northern Missouri 
overnight into Thursday morning. Thunderstorms could continue to 
track into southwest Missouri with additional development of 
thunderstorms during the morning and afternoon along and near 
outflow boundaries. For now have included vicinity thunderstorms 
for ksgf and will continue to monitor trends. 


Angle 


&& 


Sgf watches/warnings/advisories... 
MO...none. 
Kansas...none. 
&& 


$$