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Area forecast discussion 
National Weather Service Pocatello Idaho
921 am MDT Monday Jul 25 2016

Update...12z NAM and latest rap/hrrr trends pointing to
development of isolated convection along northern tier regions
this afternoon and evening. Some instability exists along this
region this afternoon and passage of shortwave axis pushing
through the region could provide enough additional lift. Have
added isolated dry thunderstorms across portions of central mtns
and along Divide this afternoon and evening. Believe moisture and
instability to be quite limited across remainder of southeast Idaho
today. Dmh


Previous discussion... /issued 217 am MDT Monday Jul 25 2016/

Short through Wednesday.
Expect hot and dry conditions today. A weak wave will increase the
chance of thunderstorms Tuesday afternoon mainly in the central
mountains and upper Snake River Highlands. Put isolated coverage
in grids. Should have less chance again on Wednesday with
continued hot weather through the entire short term with highs in
the 90s in the snake plain and 80s in the mountains. Winds are not
expected to be too strong through the period either.

Long term...Thursday through Monday.
As we roll through to the end of July it is expected to be
continued hot and mainly dry. Go to southwest flow aloft and could
see a better chance for thunderstorms over the weekend as this
southwest flow may push a bit more moisture into the region but
not overly confident at this Point of much precipitation at all.

Aviation...dry SW flow across the region today. Huston

Fire weather...a transient high pressure ridge positioned over the
region this morning will give way to an advancing trough over Oregon
this afternoon and Tuesday. Numerical models show an uptick in wind
across the central mountains and Snake River Plain as we work into
Tuesday with levels remaining well below warning criteria. Of
greater concern is the potential for dry thunderstorm activity
across the Lemhi region (fire zones 475 and 476) starting late this
afternoon up near Lost Trail Pass and then extending further south
Tuesday afternoon across most of Lemhi County. There continues to be
some ambiguity here given the differences in the numerical model
solutions, however the GFS has inched toward the bolder NAM
solution. We will have the day-shift coord further with central
Idaho dispatch on any potential red flag highlights with this
feature Tuesday. The trough exits east of the region Wednesday
morning as a modest ridge rebounds across the area supporting mostly
dry conditions with the exception of lingering instability and
moisture along the Montana border. A disturbance passing north
through Canada Wednesday/Thursday may encourage locally gusty wind
conditions across the central mountains and Snake River Plain while
remaining largely below warning levels once again. The bulk of the
instability and thunderstorm activity should remain northeast of the
Montana Divide as well. As this system passes east Thursday, the
ridge positioned over the desert SW will begin to expand
northwestward across Nevada and into southern Oregon by Friday afternoon
with attending sub-tropical moisture working north across western Nevada
and the Sierra. Once again, the models are flashing differences in
the details but the overall evolution remains consistent as we head
into the weekend and early next week as a push of sub-tropical
moisture rotates northward into and across southern and central Idaho
Saturday and Sunday ahead of a seasonally strong trough advancing
into and across the northwest states sometime Monday and/or Tuesday. The
sub-tropical moisture will promote isolated to scattered
thunderstorm development over the weekend and the incoming trough
will bring widespread gusty winds. The combination of these factors
would certainly spell greater fire activity across the landscape.


Pih watches/warnings/advisories...


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