414 
fxus65 kpih 180853 
afdpih 


Area forecast discussion 
National Weather Service Pocatello Idaho 
253 am MDT Friday Jul 18 2008 


Discussion...satellite and radar show clouds/isolated thunderstorms moving 
away from along The Divide this morning. Some clouds starting to 
develop over west central Idaho in advance of the next wave moving 
toward our area. Current forecast still calls for isolated to scattered 
thunderstorms by late morning into the afternoon and evening across the 
mountains the favored areas for development again will be across the 
central mountains and along the Montana/Wyoming borders. Locally heavy 
rain/downpours were seen again yesterday across the northern mountains 
the NAM increase keeps precipitable water values similar and in some cases 
actually increase them to near 1 inch this afternoon. On the other 
hand...GFS is the opposite with similar to lower values. 0z 
soundings showed .45 to .7 inch precipitable water values to the west last night 
so think there will be some moisture available for locally heavy 
downpours again. Severe parameters indicate sufficient shear/bulk 
shear and some cape across the north. Lapse rates would be 
sufficient for hail production. Storm Prediction Center day outlook brings the 5 
percent severe hail/wind to Yellowstone Park. All of this would 
lead to stronger storms with gusty winds...small hail and locally 
heavy downpours near The Divide up north. It appears the severe 
threat in eastern Idaho is minimal at this time...but bears 
watching. The weather should clear up quickly after sunset with a 
dry start to the weekend. Warmer weather is expected on Sat and 
sun..although we should see some clouds and a possible isolated 
tstorm by sun. Models do agree on opening up the monsoonal flow 
across the western states. However...the models disagree on how to 
handle day to day issues especially for early next week with a 
system moving ashore late in the weekend. The overall trend though 
will be a for a little cooler weather once the monsoon flow takes 
shape and for thunderstorms each day. Until better detail and agreement 
arises from the models...kept valley locales dry/storm free. Keyes 




&& 


Aviation...a surface cold front will cross southeast Idaho 
between 18 and 03z. Gusty west winds 10 to 20 miles per hour with gusts to 30 
miles per hour will accompany the front. Isolated afternoon thunderstorms are 
expected in the central mountains and upper snake Highlands as 
well Friday. 




&& 


Fire weather...the Fire Weather Watch for 409 410 412 and 477 has 
been upgraded to red flag warning for this afternoon. Expect gusty 
winds associated with an approaching cold front to combine with low 
relative humidities and critical fuel levels to produce dangerous 
fire weather conditions. Isolated to scattered thunderstorms could pose a 
problem for lightning starts across northern zones by late morning 
into this evening. A few storms are possible farther south in the 
mountains but the threat will be highest across the northern and central 
mountains 




&& 


Pih watches/warnings/advisories... 
red flag warning from noon today to 10 PM MDT this evening for 
idz409-410-412-477. 


Lake Wind Advisory from noon today to 9 PM MDT this evening for 
idz021. 


&& 


$$