686
FXUS65 KPIH 092050
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
150 PM MST Sat Nov 9 2024

.SHORT TERM...Tonight through Sunday Night.
Early afternoon satellite imagery shows a H5 ridge axis of high
pressure situated directly over ERN Idaho which is continuing to
lead to clear skies, light winds, above normal temperatures, and
dry conditions. Increasing clouds will move into our region this
evening through the overnight hours as a split H5 trough moves
onshore from the NE Pacific to the PacNW and NRN Rockies. As this
trough splits on Sunday, a closed H5 low will occlude off the
California Coast as a now weakened H5 shortwave trough is left
over the PacNW. This trough will track east throughout the day on
Sunday over the NRN Rockies with widespread cloud cover and
isolated rain/snow showers further north with best chances in the
CNTRL Mountains and ERN Highlands along the Montana/Wyoming border
regions. Any precipitation will remain very light with the latest
forecast showing up to around a T-1" of snow above 7000 feet
further north with dry conditions favored everywhere else.

As this trough departs east Sunday night into early Monday, this
will set the stage for a stronger system to move in late Monday
into Tuesday with widespread precipitation and gusty winds. Ahead
of this system, temperatures through the weekend into Monday will
remain above normal with highs in the 40s/50s and lows in the
20s/30s. MacKay

.LONG TERM...Monday through next Saturday.
Generally expect dry conditions most areas Monday with afternoon
snow moving into the central mountains, then overspreading the
remainder of the state Monday night into Tuesday. Snow levels
start out in the 6 to 7 thousand foot range Monday so only high
elevations affected, then drop to near valley floors in the 4 to 5
thousand foot range through the day on Tuesday. There is a high
probability of over 2 inches in the Sawtooths and eastern and
southeastern mountains in the 60 to 85 percent range, but those
diminish to well under 50 percent over 4 inches other than
extremely high mountain passes which may affect Galena Summit and
also in the Upper Snake Highlands. Well under an inch is expected
in the Snake River Plain. It will be very warm ahead of the cold
front Monday with highs in the 40s mountains and 50s to near 60 in
valleys. Expect some 10 to 15 mph southerly winds Monday. Behind
the cold front Tuesday will see highs only in the 30s mountains
and 40s valleys with strong west to southwest winds in the 15 to
20 mph range in the Snake Plain and Magic Valley and gusts 20 to
30 mph. Another system Wednesday and Thursday will mainly affect
the central mountains with some light snow with general 1 to 4
inch amounts there and little precipitation in grids elsewhere. At
least a chance of more widespread precipitation is in the grids
Friday and Saturday with low confidence on details. Expect above
normal temperatures Wednesday and THursday with highs in the 40s
mainly with some 30s mountains and lower 50s valleys as well.
Temperatures much colder right now for Saturday with snow levels
dropping back to valley floors and highs mainly in the 30s. GK

&&

.AVIATION...18Z TAFS through 18Z Sunday.
Not expecting impacts at the TAF sites through Sunday afternoon.
Generally nothing more than some increasing high cloud cover
tonight but any ceilings should be above 10 thousand feet. May see
some lowering clouds late Sunday afternoon to the 6 to 8 thousand
foot range at SUN with some vicinity showers but VFR conditions
will be in effect for the next 24 hours. GK

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$