Area Forecast Discussion
Issued by NWS Pocatello, ID
FXUS65 KPIH 300818
Area Forecast Discussion
National Weather Service Pocatello ID
218 AM MDT Thu Mar 30 2017
.SHORT TERM...Today through Saturday night. Initial wave of
showers are pushing through this morning ahead of a developing
split upper low pattern. We may see a brief break in the precip
around mid-morning, but the surface front associated with the
upper pattern will start edging in from the West around noon
today. The cold air associated with this system will lower snow
levels to the benches this evening. Snow accumulation will be the
heaviest in the Central Mountains...an additional 8 to 12 inches.
Winter headlines remain in effect for above 7500 ft for the
Sawtooth Range. The cold front will bring advisory-level winds to
the Eastern Magic Valley and South Central Highlands. Strong
northerly winds will develop over the Snake Plain as the upper low
sinks into the central NV/UT border late tonight while the
heaviest precipitation shifts to the south and east as well.
Residual moisture will linger into Friday, but precip amounts
should be light, and will taper off throughout the day and into
Friday night. Brisk northerly winds will continue even as
precipitation dies off, and wind speeds may again approach
advisory levels. Ridging builds back into the area on Saturday.
.LONG TERM...Sunday through Thursday night. Models in fair agreement
during the period. An upper trof moves into the Pac NW on Sun... but
models slower with precip moving into ID than previously expected.
Holding off the precip until Sun night. The upper trof deepens to a
closed low over ID on Mon...with precip expected over most of the
fcst area. The upper low moves off to the east by Tue as upper
ridging builds into the west. High amplitude ridging keeps the area
dry thru Wed...but another upper trof approaches the west coast on
Thu. The GFS brings precip into the fcst area by Thu morn...while
the ECMWF holds off until Thu night. In either case...not seeing a
strong precip signal as the main system remains offshore.
.AVIATION...A vigorous upper trof will move thru the Pac NW today
bringing rain and low cigs thru tonight. A strong cold front will
move thru eastern ID this aftn...with strong southwest winds
expected. By tonight...winds in the Snake River Plain will switch to
more northerly. Hedges
.HYDROLOGY...Continued snowmelt and QPF-driven runoff through the
period may result in ponding in some areas. River flood warnings
continue for high flows in the Bear and Portneuf Rivers. No
changes to our current suite of flood watch/warnings/advisories.
Flood Watch through Friday afternoon for IDZ017>019-022>025-031-
Wind Advisory from 10 AM this morning to midnight MDT tonight
Winter Weather Advisory until 9 PM MDT this evening for IDZ018-