FXUS65 KPIH 300901

Area Forecast Discussion
National Weather Service Pocatello ID
301 AM MDT Sun Apr 30 2017

.SHORT TERM...Today through Tuesday night.
A fast moving Pacific system will bring some mountain rain and
snow showers to southeast Idaho today. Expect little to no impacts
from the system. Expect an increase in winds this afternoon with
15 to 25 mph winds expected in the Snake River Plain and southern
highlands especially. Northwest flow aloft will set in Monday and
Tuesday with continued cool weather expected and high temperatures
staying below normal. Showers will mainly be relegated to the
mountainous regions, especially in the eastern highlands. Breezy
conditions will continue through Tuesday mainly in the Snake River

.LONG TERM...Wednesday through Sunday night. Models continue to
show a high amplitude ridge over the west Wed thru Thu. As the ridge
moves east of the Rockies on Fri...southwest flow ahead of a
deepening upper low off the Pac NW coast will begin to push moisture
into the fcst area. A few tstms are possible Fri aftn mainly over
the central mtns. As the system gains strength on Sat...upper flow
turns more southerly and showers spread across the rest of the area.
The best chances stay over the central mtns. By Sun...both models
dig the now cutoff upper low to the south. The GFS is more
progressive placing the low over CA...while the ECMWF keeps it off
shore. In either case...precip favors the central mtns and the upper
Snake Highlands while the rest of the area sees only slight chances.
By Sun night...the upper low moves slowly eastward on both models.
The GFS keeps the same precip pattern...while the ECMWF drops precip
over the entire Great Basin and most of the Rockies. Having a hard
time buying that much drying...so will favor the GFS Sun night.


.AVIATION...An upper wave moving thru the NW flow today will flatten
the upper ridge. This will result in sct showers this aftn and eve
over the central mtns and eastern highlands...and isold showers over
the upper Snake River Plain. Cig/vis expected to remain VFR. Gusty
SW winds also expected this aftn in the Snake River Plain. Hedges



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