Area Forecast Discussion
Issued by NWS Pocatello, ID

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
FXUS65 KPIH 170800

Area Forecast Discussion
National Weather Service Pocatello ID
200 AM MDT Sat Mar 17 2018

.SHORT TERM...Today through Monday night. A cold front will slowly
progress across the area today while an upper level low moves in
from the west. Cool air aloft being drawn in by the upper low will
create instability which makes the threat of thunder possible once
again this afternoon. Headlines continue to hit the Central
Mountain zones and the Upper Snake Highlands for snowfall today.
An additional 7 to 10 inches of new snow will be possible today
across the Central Mountains, and an additional 5 to 7 inches over
the Island Park area west to Monida Pass. Model guidance is split
this afternoon across the Snake plain and southern zones. NAM is
much drier in the post- frontal airmass than the GFS. Both models
generally in agreement in drying those zones this evening while
wrap-around moisture remains over the Central Mountains through
Sunday. More settled conditions will return Sunday night and
Monday while the upper low exits the region. O`Hinsberger

.LONG TERM...Tuesday through next Saturday. The GFS and to a lesser
extent the ECMWF show a weak disturbance shifting east through the
region Tuesday resulting in light precipitation across the region.
Two upstream Pacific disturbances were also noted converging on the
NW coastal waters. These systems will merge producing an extended
period of warm and moist SW flow across SRN Idaho Thursday and
Friday. The parent storm appears to reload along the coast Friday
night before advancing inland Saturday and Sunday for another round
of snowfall. Temps look to be on the warm side of climatology
Tuesday and Wednesday and then cool slightly with the incoming low
Thursday through Saturday. No wild deviations from that idea planned
on this forecast cycle. O`Huston

.AVIATION...Early morning satellite imagery was showing a closed
upper low over SW oregon with a very moist southerly flow into SRN
Idaho. Model time sections suggest lowering CIGS this morning with
LIFR anticipated at KSUN and MVFR with occasional IFR CIGS and VIS
at KBYI, KPIH, and KIDA throughout the day as the low fills and
lifts NE toward Montana. The models suggest saturated conditions at
KSUN through 03z this evening and thus will have to look closely at
adjusting the current forecast trend there after getting sense of
the trend. Valley terminals should see improving CIGS mid to late
afternoon. O`Huston


Winter Storm Warning until 6 PM MDT this evening for IDZ018-031-

Winter Weather Advisory until 6 PM MDT this evening for IDZ019.


$$ is the U.S. government's official web portal to all federal, state and local government web resources and services.