Weather

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fxus65 kggw 281517 
afdggw 


Area forecast discussion 
National Weather Service Glasgow Montana 
917 am MDT Thursday Aug 28 2008 


Short term...for northeast Montana...today through Saturday... 
no update planned for the forecast this morning. Weak high 
pressure over the region with northwest flow aloft. Mostly clear 
skies although some cloud may move in later today from weak 
Chinook Arch. Expect breezy conditions by afternoon as winds mix 
to the surface...but wind aloft not as strong as the past few days 
so should remain below lake wind criteria. With more sunshine... 
temperatures should be warmer than yesterday. Current forecast in 
good shape. Ebert 


Previous short term...upper trough has exited into the Dakotas with 
northwest flow aloft now over the area. This will remain the case 
today and tonight before the upper flow flattens out to more zonal 
for Friday as a very weak semblance of an upper ridge moves 
across. By Saturday a trough digs southeast into the West Coast 
which amplifies the pattern over North America and results in 
southwest flow aloft over eastern Montana. Were it earlier in the 
Summer would definitely be looking hard at afternoon potential for 
thunderstorms. However this time of year it becomes a much lesser 
probability. Models currently indicating atmosphere through the 
afternoon Saturday to be fairly stable. So for now will keep 
Saturday afternoon dry. Still cool for late August today although 
temperatures should rise a few degrees from yesterday. Surface 
high moving in from the west should provide some gradient to drive 
wind at least into the breezy category this afternoon. Lapse rates 
being depicted by the models not all that great for helping to 
drive the wind a great deal more...and wind aloft is expected to 
be decreasing today as mixing becomes better. For now looks like 
speeds should top out between 15 and 20 miles per hour this afternoon most 
spots. Will hold off on a lake Wind Advisory and allow the morning 
update shift to further assess. Warmer air continues to make its 
way into the area over the next few days so each day to be warmer 
through Saturday ... should see US up into the 90s to around 100 
once again. 


Long term...Saturday night through Thursday... 
00z models continue to bring a strong Pacific trough into the 
intermountain west late this weekend and early next week. 
Uncertainty still exists between various model runs...which will 
impact rainfall amounts and temperatures. GFS and European model (ecmwf) give the 
local forecast area a good chance at rainfall. However...Canadian 
continues to be farther west with the upper trough. Closer 
examination of the synoptic features Sunday and Monday reveals a 
cold front...which moves through the County Warning Area...and then stalls over 
the Dakotas as a surface wave develops along the front. 
Meanwhile...an upper jet streak extends from western Montana into 
central Canada. There is a possibility that rain develops along the 
cold front in the Dakotas...and over central Montana with the best 
dynamics associated with the right entrance region of the upper 
jet. With this scenario the local forecast area could miss the 
best moisture. Given the uncertainty very few changes were made to 
the existing pop grids. 


As for temperatures...the ensemble MOS numbers show significant 
Standard deviation on Sunday and Monday...with values of 5 and 6 
respectively at ggw. The operational GFS is among the colder members 
and the coldest scenario would be high temperatures in the 50s. 
Again with the uncertainty very little changes were made to the 
existing temperature grids. 


By the middle of next week...weak upper ridging 
develops...followed by another trough. Ajz 


&& 


Aviation... 
VFR for the next 24 hours. A west-northwest wind around 10kt will 
increase to around 15kt...with gusts to 25kt...this 
afternoon...and then diminish after sunset. Ajz 


&& 


Glasgow watches/warnings/advisories...none. 


&& 


$$ 


Weather.Gov/Glasgow