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Area forecast discussion 
National Weather Service Springfield MO 
557 am CST Wednesday Jan 7 2009 


..update to aviation... 


Discussion... 


Forecast challenges deal primarily with temperatures through the 
week...turning to precipitation chances Friday night into Saturday as a 
cold front moves into the area. Looks like a significant cool down 
will take place next week as well. 


Currently/today...looks like another dry trough extends from central 
Iowa to just south of Kansas City...back into southeast Kansas 
this morning looking at regional surface observations. A narrow 
area of stratocu behind the trough pushing into northwest Missouri 
and extends back into southeast South Dakota that may mess with 
temperatures some today. Will continue to monitor for possible 
lowering of maximum temperatures today. Upper shortwave with this 
clipper system currently over central Nebraska is expected to move 
into southern Missouri this morning. Not expecting much with this 
system initially today. It does show another shot of cold air 
moving into the area and some light snow is being reported back 
over Nebraska and South Dakota that may move into our eastern 
counties this evening. Models do forecast some minor quantitative precipitation forecast over our 
eastern counties this evening...so will go with some slt chance 
probability of precipitation this evening. 


By Thursday...should start to see a warm up as winds shift to the 
southwest Thursday afternoon. Strong warm air advection forecast beginning 
Thursday afternoon and continuing into Friday with 850mb 
temperatures rising from -2c Thursday morning to +10c Friday 
morning. Based of local climate study...went above both met and 
mav Friday on temperatures and should see middle 60s across southwest 
Missouri Friday with low 60s elsewhere. By Friday afternoon...GFS 
is depicting a surface low across northern Illinois with strong 
trailing cold front pushing into southern Missouri by Friday 
afternoon. European model (ecmwf) much slower on this feature...not moving the 
front through until Friday evening. With European model (ecmwf) supported by 
WRF...decided to go with this solution. Later shifts will need to 
watch this to see if the GFS catches on in the next couple model 
runs. Regardless...not much moisture to work with and only went 
with slt chance probability of precipitation for Friday evening. 


May get one more warm day Sunday as winds shift to the 
southwest...but after that...it looks like we are going to be in 
for some very cold temperatures as a series of cold fronts push 
into the area. Again...not much in the way of precipitation...but lots of 
cold air. In fact...medium range guidance is showing lows in the 
teens Tuesday and Wednesday with highs not making freezing through 
the first part of next week. 


Claycomb 




&& 


Aviation... 


VFR conditions will prevail at the Joplin and Springfield 
terminals through tonight. Scattered to broken middle level cloud 
cover will persist through tonight. Winds will shift to the 
northwest later tonight as a trough of low pressure swings across 
the region. 


Foster 




&& 


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


$$