Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus65 kboi 072200 

Area forecast discussion
National Weather Service Boise Idaho
300 PM MST Sat Dec 7 2019

Short term...tonight through Tuesday night...a low pressure
system along the California/or coast will move inland overnight.
Precipitation development ahead of this system will overspread the
area late this afternoon into tonight from southwest to northeast.
The heaviest precipitation will fall across Baker County,
northern Harney and malhuer counties, the Weiser basin and
W-central Idaho and Boise Mountains. Lighter amounts and less
certainty in precipitation chances across much of the snake plain
to the Idaho/Nevada border. Snow levels will remain between 5-6kft
overnight as W-SW flow continues ahead of the main trough. Most of
the accumulating snow will be above 5500 feet through Sunday
morning with additional accumulations of 3-6 inches. The upper
trough kicks through the region Sunday cutting off the
precipitation as flow backs around to the northwest. Drier
conditions follow for early next week as an upper ridge builds
into the region. Valleys will remain cool with the potential for
valley fog/stratus Monday and Tuesday under an accompanying

Long term...Wednesday through Saturday...a weak upper trough
slides over the region Wednesday bringing a slight threat of
showers, but the bigger threat of precipitation comes by the end
of the week. Models have been in good agreement for days showing a
very moist flow moving into the Pacific northwest Friday. The GFS
indicates precip water values over the 90th percentile, so likely
pops already in the forecast for the mountains by the end of the
week. Snow levels at this time should be above 5500 feet Friday
afternoon. Temperatures generally near normal through mid week,
then 5 to 10 degrees above normal by the weekend.


Aviation...VFR with areas of MVFR/IFR conditions in rain
and mountain snow along with low clouds. Snow level around 5500
feet. Mtns obscured. Widespread MVFR/IFR aft 08/01z as additional
rain and snow move back into the region. Precipitation begins to
taper off from west to east aft sunrise Sunday but remaining across
idahos west central mountains through the afternoon. Surface wind
south to southeast 10 to 15 kts kjer-keul, otherwise 5 to 10 kts.
Winds becoming southeast to southwest aft midnight and west to
northwest after sunrise. Winds aloft near 10kft: southwest 30 to 50
kts, becoming west to southwest 08/06z through 08/12z, then west to
northwest 20 to 30 kts.


Boi watches/warnings/advisories...




National Weather Service Glossary of Abbreviations