527 
fxus65 kgjt 192009 
afdgjt 


Area forecast discussion 
National Weather Service Grand Junction Colorado 
209 PM MDT Tuesday Aug 19 2008 


Short term...today through Thursday night... 
upper level ridge over the forecast area this afternoon and limited 
moisture has resulted in a fairly quiet day as far as convective 
activity is concerned. However...still expect a few storms to pop 
by late this afternoon as late heating finally helps break through 
subsidence inversion near 550 mb. Approaching long wave trough over 
northern Nevada will be bringing in slightly better moisture this 
evening...along with a glancing shot of cooler air aloft. This will 
will aide in the development of early evening convection across the 
higher terrain of eastern Utah...with activity glancing the eastern 
Utah valleys before midnight. Not much rain expected with any 
storms through this evening with precipitable water values remaining 
below one half inch. 


The above mentioned wave passes to our north on Wednesday... 
suppressing the ridge over the central rockies. Convection is 
expected to fire along the leading edge of this wave by early 
afternoon...with the focus of activity over the northern mountains. 
Subsident conditions settle in quickly behind this wave...with 
quick clearing expected from west to east by Wednesday nigh as flow 
aloft becomes more westerly. Dry and seasonal conditions then hold 
through Thursday night. 


Persistence still key as far as temperatures are concerned through 
Thursday night. 


Long term...Thursday night through Tuesday... 
system will move across the northern rockies and push The Four 
Corners high south and flatten it somewhat. This will keep winds up 
a bit and a slim change of showers. High pressure returns Sunday 
and Monday with a slight increase in moisture for the south. Current 
forecast is in good shape so only minor tweaks to the package. 


&& 


Aviation... 
area forecast discussion few isolated thunderstorms are possible over 
the high terrain this early this evening...mainly across eastern Utah 
and southwest Colorado. Otherwise...looks like VFR conditions to be 
prevalent over the area at least through the remainder of the week as 
dry weather will be dominant. 


&& 


Fire weather... 
no highlights planned...but upper wave on Wednesday and the system moving 
across the northern rockies Thursday night will generate some localized winds 
Wednesday afternoon and Thursday afternoon. Some areas in NE Utah as well as 
northwest Colorado /zone 201/ may experience marginal red flag criteria for a 
short time during the middle or late afternoons...but not sufficiently 
widespread to warrant fire weather highlights. Afternoon humidities 
in these areas are expected to be 13-16 percent with localized wind gusts 
perhaps 25-30 miles per hour. 


&& 


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


$$ 


Short term.....Jdc 
long term......djc 
aviation.......jdc 
fire weather...jad