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Area forecast discussion 
National Weather Service Pocatello Idaho
325 am MST Friday Feb 12 2016

Short through Sunday. First of series of shortwaves
has passed through east Idaho with light precipitation in eastern
Highlands north of Soda Springs. Upper ridge still in place but
weakened and trend is expected to continue through tonight as
stronger feature works into the coast. Patchy fog/stratus apparent
on Sat imagery this morning along Utah border. Will keep in place
this morning and then a brief appearance overnight ahead of next
arriving feature. GFS and NAM showing better timing agreement
tonight but GFS still holding on to more moisture than NAM. Both
models keep most of the precipitation for Saturday north of The
Divide. GFS holds on to more middle level moisture with this feature
through the day Saturday especially further south. The NAM remains
slightly drier but does produce weak orographically forced quantitative precipitation forecast
along the southern Highlands. Both models still producing stronger
winds during the day Saturday and have kept winds elevated through
the snake plain and higher elevations mainly in the afternoon.
Believe this should be the end of the low level inversions as
well. Brief break in the precipitation late in the day but next shortwave
feature quick to arrive...bringing another round of precipitation into
east Idaho late Saturday night. Models remain in good agreement
with timing and quantitative precipitation forecast with this second system. Northwest flow favors
precipitation focused over higher elevations with drier conditions
through the snake plain especially in the Lee of the central mountains
this system wetter than prior feature and have kept snow totals
close to previous forecast with up to 6 inches along Wyoming
border...2-4 inches most higher elevations...and less than an inch
in the snake plain and most valley locations. Another breezy day
on tap with favorable surface gradient thus kept winds elevated
through Sunday as well. Dmh

Long term...Monday through Friday...general isolated to scattered
snow showers expected through the eastern and central mountains with
rain showers in the valleys in these areas on Monday into early
Tuesday. Some lingering activity possible in the eastern areas
Tuesday with the rest of the region under building high pressure
through Wednesday. Models in quite good agreement for this system
with snow totals perhaps 2-4 inches in the eastern Highlands and 1-2
inches in the central mountains. Temperatures still on track to warm
into the middle 40s for most of southeast Idaho and even to low 50s for
the eastern Magic Valley/southern Snake River Plain early next week.
Beginning late Wednesday next weather system expected to approach
from the southwest...bringing a rain/snow mix through Friday.


Aviation...Ida showing mist early this morning but should not last
past 10am. Some indications from models Show Low ceilings and/or
mist development again late this evening and overnight. Low
confidence in this happening and with the timing but it remains
possible. Concerns elsewhere are little and expecting VFR
conditions at the remainder of the sites the next 24 hours. Np/dmh


Air stagnation...upper ridge weakening but low level inversions
remain in place this morning. Patchy fog still existing in the
southern Highlands mainly between interstates 15 and 84 and in the
Cache Valley. Poor air quality will continue in these areas. The
ridge will continue to weaken today and collapse completely by
Saturday as a system slides through the region. This feature
Saturday will bring a threat of precipitation mainly north half of
east Idaho but more importantly...increased winds should erase
what is left of the low level inversions. Unsettled conditions
will continue through the remainder of the weekend but high
pressure is expected to return for the first half of next week.


Pih watches/warnings/advisories...


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