547 
fxus63 kmpx 051956 
afdmpx 


Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota 
255 PM CDT Sat Jul 5 2008 




Discussion... 
the forecast challenge tonight and over the next few days are 
precipitation chances. A short wave trough depicted in the latest infrared 
satellite loop will continue to advance east over the upper Midwest 
by midday Sunday. After a couple of nice days...the weather pattern 
will transition to more wetter pattern as a series of short wave 
troughs pass over the upper Midwest over the next few days. No 
widespread rain showers or thunderstorms are anticipated at this time. 
The latest composite radar image showed a linear area of showers and 
isolated thunderstorms ahead of the shortwave trough over western Minnesota 
into eastern South Dakota. These showers and storms are expected to 
move east over into central Minnesota before daybreak Sunday. Dewpoints 
have surge into the upper 60s and lower 70s over parts of west 
central Minnesota. Airmass should continue to moisten ahead of the trough 
tonight and Sunday. 


Current it look like the best area of receiving some rain will be 
over the southwest half of our County Warning Area tonight and Sunday morning. 
Another stronger shortwave as indicated by the nam80 will move over 
the upper Midwest on Monday. 


By middle week of next week...the upper air pattern transition back to 
more Summer-like pattern with upper ridge amplify back over the 
western half of the Continental U.S.. so warm and dry weather anticipate for 
much of the forecast area during the latter half of the week. 
&& 






Aviation.../18z taf issuance/ 


Changes are on the way tonight as showers and thunderstorms will 
become possible. Moderately strong southerly winds have set up 
across southern Minnesota and are creeping into west central 
Wisconsin early this afternoon. Highest speeds will be across west 
central Minnesota with sustained speeds from 18 to 23 kts and 
gusts to near 30 kts at times. VFR conditions will continue 
through much of the evening with some middle and high clouds 
scattered about this afternoon with a few puffs of cumulus developing 
in spots...with increasing middle cloud cover later this evening. An 
upper level trough and a surface cool front will move towards the 
area tonight. Showers and thunderstorms are expected to develop 
late this afternoon across central north and South Dakota and move 
eastward. Kaxn may see some activity between 03 and 06z but best 
chance will be around or soon after 06z. Kstc should also see this 
activity pass by after 06z. Another area of showers and 
thunderstorms is expected to affect southwest Minnesota later on 
tonight as moisture increases into that area. Krwf is expected to 
see showers and thunderstorms late tonight. The tough sites will 
be kmsp and krnh. These areas may be in a lull area between to the 
two areas of storms so have opted for prob30 mention of activity 
late tonight with vcsh at kmsp as well. Will need to watch things 
later today to determine if there will be an increased potential 
there. Any shower and thunder activity will linger into middle Sunday 
morning. There is a chance for MVFR ceilings behind the activity that 
crosses kstc Sunday morning. Strong wind gusts and small hail will 
be possible with storms early tonight with a decreasing chance 
towards daybreak. MVFR or lower visibility will also be possible 
under the heaviest storms. Additional showers and thunderstorms will 
be possible again Sunday afternoon. Another concern for tonight is 
low level wind shear potential with wind speeds increasing to 35 to 
45 kts between 1500 and 2500 feet. However...speeds below that layer 
remain elevated so the transition to these strong winds should not 
be too abrupt. ..mdb.. 


&& 


Mpx watches/warnings/advisories... 
Minnesota...none. 
WI...none. 
&& 


$$ 


Jvm/mdb