Scientific Forecaster Discussion
fxus65 kpih 202047
Area forecast discussion
National Weather Service Pocatello Idaho
247 PM MDT Fri Sep 20 2019
Today through Monday...from current radar imagery, widespread
light to moderate precipitation is in the mountains with little
precipitation in the eastern Magic Valley and Snake River Plain
mainly west of Blackfoot. Snow levels are around 8000 to 8500
feet this afternoon looking to drop to 7500 to 8000 feet this
evening. Precipitation is from an upper level low centered over
the area currently. This low is expected to weaken and move
northeast through the evening into tomorrow morning. Expect breezy
conditions mainly this afternoon into the early evening. Look for
0.10 to 0.50 inch of additional precipitation for mainly our
northeast areas across the upper snake Highlands encompassing
Fremont County and portions of counties around Fremont County.
This also includes the northern and central eastern Highlands
along the Wyoming border. Valleys outside of the upper snake
Highlands will get an additional trace to 0.05 inch of rain.
Mountains elsewhere will receive rain of 0.05 to 0.20 with snow of
around 1 inch above 8000 feet. Look for 1 to 2 inches of snow
above 8000 feet mainly for the upper snake Highlands and the
eastern Highlands. Locally higher amounts up to 4 inches may be
Brief high pressure ridging builds in late Saturday into Sunday.
With gradual clearing and overall light winds, Saturday morning
looks to be cold with temperatures in the upper thirties to lower
forties across the Snake River Plain and eastern Magic Valley.
Models continue to show cloud cover over area which will keep the
temperatures slightly higher. If clearing occurs (which is not
expected) then temperatures will drop slightly more for tomorrow
morning's low temperatures. Mountain areas will certainly see
freezing temperatures Saturday morning.
For Monday, models have changed yet again. The GFS model now forms
an upper level low west of our area dropping it south, very
similar to the European model (ecmwf) model. Both models now show little, if any,
precipitation over our area for Monday.
Long term...Tuesday through Friday. Both models show our area in
a west northwest upper level flow with overall weak high pressure
building back into our area bringing warmer and drier conditions
Tuesday and, particularly, Wednesday. Thursday the flow changes to
a slight west southwest flow ahead of wet, upper level low system
that starts to move over our area late Thursday into Friday.
Look for temperatures around 10 to 15 degrees below normal
today. Temperatures warm by Sunday but still look to be 2 to 4
degrees below normal. Temperatures drop slightly Monday and then
rise back to 2 to 4 degrees below normal Tuesday and Wednesday.
Then expect temperatures 5 to 10 degrees below normal Thursday
and, particularly, Friday as the next system moves over our area.
upper low over Idaho has dry slotted byi and pih today with rain and
MVFR ceilings at Ida and dij. Low ceilings also at pih and byi
even minus the rain. Expect periods of rain at all sites through
this evening and continuing at dij on Saturday. Kept MVFR at dij
through 18z Saturday and think all other sites should improve to VFR
in the 05z-10z time frame Saturday morning.
a cold upper low is over southern Idaho with very cold temperatures
and rain and snow showers over much of the region. Some areas got
dry slotted but wetting rains have occurred over much of zones 410
and 411 especially today. Rain will continue this evening over much
of zones 410, 411 and 413 mainly and continue into Saturday morning.
Sunday will be dry and warmer and the Pacific system is weakening
for Monday and only expect a slight chance of showers with little in
amounts expected. Tuesday and Wednesday look dry with the next
chance for precipitation Thursday into Friday. Mild temperatures
are expected Monday through Wednesday with cooling late next week
with the next system.