Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Boise Idaho
837 PM MDT sun Aug 31 2014
Discussion...decreasing clouds and winds this evening. Dry
northwesterly flow will persist through Tuesday with mostly clear
skies and light winds. Warmer air aloft will work its way across
the region with Tuesday ahead of a trough digging along the Pacific northwest
coast. Current forecast on track with no updates.
Aviation...VFR under clear skies over southeast Oregon and SW Idaho
tonight and Monday. Westerly surface winds mostly 10 kts or less
increasing to 20 kts at 10k feet mean sea level.
short term...tonight through Tuesday...residual moisture
residing in a west-northwest flow with daytime heating promoted scattered
cumulus clouds across the northern portions of southeast Oregon
and southwest Idaho this afternoon. The clouds have shown little
vertical extent as the air mass has stabilized since
yesterday...thus we are not expecting any showers with the clouds.
The clouds will diminish overnight with clear skies expected late.
Gusty west-northwest winds will also diminish this evening. The combination
of clearing skies and light winds will bring a cool start to Labor
Day. Labor Day through Tuesday...flow aloft will turn west-southwesterly ahead
of an upper trough and cold front which will move into the Pacific
northwest. This will result in a warming trend...along with mostly
clear skies and light winds. Highs on Tuesday will be near to
slightly above normal.
Long term...Tuesday night through Friday...fairly good agreement
in models that a dry cold front will push through the area Tuesday
night. This in response to upper level trough that moves from near
Vancouver Island on Tuesday night...to North Dakota by Thursday
morning. Trough looks far enough away that moisture will be north
of the area...and we have removed mention of precipitation during the
period. Most noticeable will be temperatures about 10 degrees
below normal on Wednesday behind the front. Remnants of the trough
just linger over the area through Friday...with a piece deepening
off the California coast...which means that temperatures will be
slow to recover...and will still be about 5 degrees below normal
Friday night through Sunday...dry northwesterly winds will be the
predominant flow in our region as the upper level trough moves to
the east. The warming trend will continue through the weekend as
the atmospheric pressure builds and dry conditions remain due to
low moisture transport.
previous short term...bw
previous long term....tb/ab