672 
fxus65 kpih 180810 
afdpih 


Area forecast discussion 
National Weather Service Pocatello Idaho 
210 am MDT Thursday Mar 18 2010 


Short term...today through Saturday night. Trough moving along 
the British Columbia and Alberta border will push southward into 
eastern Montana today while a baroclinic zone develops across the 
southern and eastern Highlands. So far this morning...dry air in 
the low and middle levels is preventing any precipitation from 
forming over the forecast area. Later this morning and this 
afternoon...instability is expected to increase across the 
aforementioned areas which will allow scattered rain showers and 
higher elevation snow showers to form. With the trough sticking 
east of The Divide and limited moisture expected in Idaho...expect 
precipitation to be light with only a few inches of snow falling 
in the highest mountains. While high temperatures will be 
noticeably cooler than the last few days...snow levels will remain 
above 6000 feet. Flow turns north-northwesterly tonight and into 
Saturday. Some orographically induced snow showers are possible 
primarily in the southeastern Highlands but should diminish 
quickly Friday evening. A ridge shifts eastward into the area on 
Saturday and will result in dry weather and mild temperatures. 


Long term...Sunday through Thursday. Upper ridging will begin to 
move out of the forecast area on Sunday as an upper low moves into the 
Pacific northwest by Monday morning. West to SW flow ahead of this system may 
bring in enough Pacific moisture to set of some light precipitation over the 
northern part of the forecast area Sun night into Monday morning. The GFS 
and European model (ecmwf) are in general agreement with the uper low dropping into 
the Great Basin by Tuesday morning. This will increase the chances for 
precipitation Monday through Tuesday. The upper low drops into southern Arizona by Wednesday 
morning ... a ridge builds into the Pacific northwest. This should 
result in mainly dry conditions for Wednesday and Thursday. Hedges 


&& 


Aviation...an upper trough will move southeastward through Idaho this morning. 
Overall conditions are expected to remain VFR...but there may be 
brief periods of MVFR ceilings in the Snake River Plain this morning. SW 
winds will pick up this morning in the wake of the cold front and 
continue into the afternoon. Hedges 




&& 


Pih watches/warnings/advisories... 
none. 
&& 


$$