364 
fxus65 kgjt 212154 
afdgjt 


Area forecast discussion 
National Weather Service Grand Junction Colorado 
254 PM MST Friday Nov 21 2008 


Short term...tonight through Sunday... 
moisture-starved shortwave passing today has brought some middle and 
high clouds to the north...which should diminish this evening. Also 
generating some local surface breezes this afternoon. Weak cold front 
has had minimal effect on temperatures this afternoon. 


Upper level ridge of high pressure moves overhead later tonight and 
Saturday for dry weather. Pacific moisture streaming inland will 
keep some high cloudiness around...but in general Sat should be 
mostly sunny. Another shortwave currently approaching the Washington/or coast 
crosses the northern rockies and drops down into Colorado on Sunday 
afternoon. Limited moisture and minimal cold advection/dynamics 
indicated...so no precipitation is expected. Temperatures a few degrees cooler than on 
Sat. 


Long term...Sunday night through Friday... 
dry with warming temperatures for the beginning of the week with a 
storm system moving in by Thanksgiving. 


Upper ridge begins to build over the forecast area Sunday night. 
Ridge axis rotates over eastern Utah and western Colorado late Monday. 
Expect dry and warming conditions. A split but phased Pacific system 
moves inland late Tuesday. The southern portion is already closed 
off west of California before landfall. The northern portion quickly moves 
east over the northern rockies. The southern portion slows slightly 
and opens as it ejects northeast over the central rockies. The 
models start to diverge at this point on late Wednesday and 
Thursday. The GFS keeps the trough together and moves it overhead 
the ec is slightly slower and splits the trough with the stronger 
southern part moving over nm. This system should continue to with a 
stronger low entering from the west late Thursday. Increased the probability of precipitation 
and clouds for Thanksgiving and trended more with the GFS with 
timing. The next low digs south along the coast with the ec slightly 
farther inland and the GFS slightly stronger. 


&& 


Aviation... 
VFR conditions will predominate into next week. Areas of MVFR or even 
locally IFR conditions possible over the Colorado northern mountains..north of 
an ase to lxv line...until 02z. 




&& 


Gjt watches/warnings/advisories... 
Colorado...none. 
Utah...none. 


$$ 


Short term.....Jad 
long term......as 
aviation.......jad