Area Forecast Discussion
Issued by NWS Boise, ID
FXUS65 KBOI 300901
Area Forecast Discussion
National Weather Service Boise ID
301 AM MDT SAT JUL 30 2016
.SHORT TERM...Today through Sunday...Monsoon moisture that has
been over Nevada will creep north into the forecast area today.
But increasing westerly flow around an upper-level trough over
British Columbia will quickly push it back out of the area
tonight. Models appear slightly faster with the dry air pushing in
from the west, and have further limited thunderstorm coverage
today further south and east. Low level moisture is fairly
limited, and any storms that develop will be moving rather quickly
from the west at 20-30 mph, so main threats will be lightning and
gusty winds. This still supports the fire weather watch now in
effect. Temperatures 5 to 10 degrees cooler on Sunday, but still
near seasonal normals. Upper level westerly winds increase on
Sunday, so should see breezy conditions in the Snake Plain, and
over the ridgetops.
.LONG TERM...Sunday night through Friday...Dry westerly flow aloft
will shift into the southwest Monday and Monday night ahead of an
approaching upper level trough. This system will move east across
Washington and northern Idaho Tuesday and Tuesday night, with
precipitation staying along and north of the Canadian border. The
main effects on our area will be breezy northwest winds and cooler
temperatures, with highs Tuesday and Wednesday 10 to 15 degrees
lower than Monday. A warming trend Thursday and Friday will precede
the next upper level trough. Models show the center of this system
over the British Columbia coast Friday morning, with southwest flow
aloft remaining dry over southeast Oregon and southwest Idaho. It is
still uncertain whether monsoon moisture will will cross the Nevada
border on Friday.
.AVIATION...VFR. Isolated thunderstorms along the Nevada border will
spread north this afternoon and persist through this evening, mainly
staying south of a KREO-KMUO-KJER line, but isolated afternoon
thunderstorms are possible over the Boise Mountains and in the
Fairfield area. Smoke layers with MVFR visibilities will continue in
the Lowman area and surrounding valleys. Also expect smoke in the
Snake River Valley this morning with local MVFR visibilities.
Surface winds variable less than 10 kts this morning and west to
northwest around 10 kts this afternoon. Winds aloft west to
northwest 10-20 knots through 10K feet MSL.
Outlook for Sunday...Mainly VFR. Smoke will continue in the Boise
mountains, filtering into the Snake River Valley during late night
and morning hours. Otherwise expect VFR conditions with mostly clear
skies and breezy northwest winds.
ID...Fire Weather Watch from noon MDT today through this evening
OR...Fire Weather Watch from noon MDT /11 AM PDT/ today through this