489 
fxus63 kbis 051911 
afdbis 


Area forecast discussion 
National Weather Service Bismarck ND 
210 PM CDT Sat Jul 5 2008 


Short term...tonight through Tuesday night 
a classic active early July upper air pattern is in place. 
Boundary layer dewpoints of 60 and above are either in the state or 
close enough to be rapidly advected in. The southern edge of the 
westerlies is over North Dakota and every passing short wave has 
the potential to produce thunderstorms. Our first round will be 
this afternoon and tonight and then again on almost every day as 
weak short waves keep peeling off The Rockies. 


I expect temperatures to be seasonable. 






Long term...Wednesday through Saturday night... 


Models/ensembles in better agreement with the long term today. 
Wednesday the models indicate a weak upper ridge over central North 
America which flattens on Thursday ahead of the next longwave 
trough. By Friday the flow turns southwesterly and allows shortwaves 
to move through the plains. Timing is very suspect at this time and 
went with consensus of keeping only slight chances or not mentioning 
precipitation at this time...especially with capping and timing of 
shortwaves. 


Concerning temperatures...Wednesday with northwest flow should be 
the coolest day with highs upper 70s to middle 80s. And 80 to 90 for 
Thursday through Saturday. 


&& 


Aviation... 


Surface trough over central North Dakota this afternoon with upper 
level shortwave along and behind the front. This front is the focus 
of strong to severe thunderstorms expected over central and eastern 
North Dakota...likely after 20z or 3pm. Atmosphere ahead of this 
trough is capped and needs surface trough and/or upper disturbance 
to get storms started. Behind this trough there is another line of 
instability associated with the tail end of the upper shortwave. 
This line will drift across western North Dakota early this 
afternoon and reach central North Dakota by late afternoon/early 
evening. Thus thunderstorms expected mainly this afternoon for 
western taf sites...and afternoon and evening central and eastern 
taf sites. Strong winds and hail the main threats. 


&& 


Bis watches/warnings/advisories... 
none. 
&& 


$$ 


Rl/jv