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fxus65 ktfx 211010 
afdtfx 


Area forecast discussion 
National Weather Service Great Falls Montana 
410 am MDT sun Mar 21 2010 


Discussion... 
today through Tuesday...an upper ridge over the area this morning 
will move east this afternoon. There will be quite a bit of 
cloudiness over the plains but little threat of precipitation. Then 
an upper trough will move through the area Monday. Behind the 
upper trough northwest flow aloft will develop Monday night then 
continue through Tuesday. A weather disturbance aloft embedded in 
this northwest flow will move through the area on Tuesday but 
there is little if any lift with it and not a whole lot of 
moisture. As for the High Wind Warning..winds are not as strong 
as was expected over the northern Rocky Mountain front early this 
morning. However some guidance is suggesting a possible increase 
in winds towards morning so will hold onto the High Wind Warning 
for that area through the morning. With mondays upper trough it 
looks like the main lift and moisture will affect the central and 
southern zones. Instability will also play a role. As has been 
advertised this is a relatively warm system so plains and valleys 
should see a mix of rain and snow. Still lower southwest valleys 
could see up to a couple of inches of snow. For higher mountains 
of southwest Montana am coming up with up to a foot of snow. Am 
coming up with 2 to 4 inches for the West Yellowstone area. With 
not much lift with tuesdays weather disturbance aloft and a 
stabilizing airmass have backed off on the chances of 
precipitation. Blank 


Tuesday night through Friday night...moisture associated with the 
Pacific system that impacted the region Tuesday will linger across 
central and southwest Montana until Tuesday night. Any precipitation 
received should be mountain snow and mixed precipitation over the 
plains and valleys. Tuesday night and Wednesday...a transient 
upper-level ridge will pass over the region with drier conditions 
and warmer temperatures around seasonal averages. Models differ 
slightly Thursday into Friday with scattered light precipitation 
moving into the region from the west. As a result...stayed close to 
climatology for temperatures and a little above climatology for 
precipitation during the second half of the extended forecast. 


Saturday and Sunday...latest models differ on timing of a quick 
moving Pacific disturbance expected to move into the region over 
the weekend. There will be a chance for snow showers along the 
Continental Divide and the central mountains. The plains can 
expect isolated rain and snow showers through the period. On the 
Central Plains temperatures are expected to be near average on 
Saturday and slightly above average on Sunday. 


&& 


Aviation... 
updated 0455z. 
VFR conditions will persist across north central...central...and 
southwest Montana into Sunday evening....unless otherwise stated 
below. The upper level ridge of high pressure will steadily be 
flattened through the period by a series of disturbances...which 
will bring increasing mainly high level cloudiness to the area. 
Westerly winds aloft will also increase during this period and will 
be strongest along the Rocky Mountain front and between 06z and 18z 
(gusts could reach 60 kt). Winds will remain breezy over the plains 
overnight (kctb kgtf 15 to 25 knots - khvr klwt - 10 to 15 kt). These 
winds will then increase on Sunday...with gusts reaching 25 to 35 knots 
at kctb and kgtf. Winds in most Southwest Valley locations will 
remain light...but khln could receive gusts to 25 knots Sunday 
afternoon. Showers will develop over the western Montana Mountains 
around 00z and spread out over the plains...but the main impact will 
be to obscure mountain tops. Coulston 


&& 


Preliminary point temps/pops... 
gtf 60 35 48 28 / 0 30 70 60 
ctb 56 30 46 25 / 0 20 50 50 
hln 63 34 48 28 / 0 50 80 20 
bzn 57 33 45 23 / 0 30 80 50 
wey 46 22 39 13 / 0 40 80 70 
dln 54 32 44 24 / 0 40 80 20 
hvr 52 28 44 20 / 0 10 30 40 
lwt 54 34 45 27 / 0 20 50 60 


&& 


Tfx watches/warnings/advisories... 
High Wind Warning until noon MDT today northern Rocky Mountain 
front. 


&& 


$$ 


Short term...blank 
long term...gustafson/Saucier 
aviation...gustafson 


Weather.Gov/greatfalls