Area Forecast Discussion
Issued by NWS Pocatello, ID

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
FXUS65 KPIH 190850

Area Forecast Discussion
National Weather Service Pocatello ID
250 AM MDT Thu Jul 19 2018

.SHORT TERM...Today through Saturday.
Dry westerly flow aloft will bring another dry and hot day with
areas of 10 to 15 mph winds in the afternoon with gusts 20 to 25
mph. flow aloft turns more southwesterly Friday and Saturday and
this will allow monsoonal moisture to push north into southeast
Idaho and expect and increase in thunderstorm coverage late Friday
through Saturday especially in the southern highlands near the
Utah border. It will remain warm with temperatures continuing to
be above normal with highs in the 80s mountains and 90s in the
Snake Plain.

.LONG TERM...Sunday through Thursday.
A wave passing to north will shift flow to a more westerly
direction Sunday and cut off the monsoonal flow for a period with
mainly dry conditions and a much less chance for thunderstorms
Sunday through Tuesday. May see a slightly better chance Wednesday
but confidence low in any precipiation in the long term. Extremely
hot conditions will continue Sunday through Thursday with well
above normal high temperatures continuing.


.AVIATION...Extremely dry air mass overhead, with only a brief
chance of clouds late tonight at KBYI and KPIH. Would expect normal
thermally-driven wind shifts; the only exception may be KSUN, where
it looks like the early afternoon southeast wind may not develop.
The wind has the potential to be gusty with 20KT at the boundary
layer for the afternoon for the Snake River plain eastern Magic
Valley airdromes. Smoke could be a factor, but believe enough wind
aloft and enough instability that smoke will not impair aircraft
operations. Messick


.FIRE WEATHER...Very dry air continues with temperatures warming
slightly, so humidity will be down even more. Fortunately, the high
pressure is keeping wind weak, with only the high elevations which
are not yet critical (above 7000ft elevation) in the central Idaho
mountains the only place where wind and humidity combine for a
critical weather pattern. Fri continues dry and hot, but wind should
be weaker. The upper level ridge has some moisture that starts to
move in, mostly Fri night and into Sat, that will bring back a weak
threat of showers and thunderstorms, mainly for southern and eastern
zones. The threat is over by Sun morning, however. A warming trend
resumes with the heat and low humidity peaking/bottoming out on Wed.
Beyond the Fri night/Sat thunderstorms, there is a slight chance
threat again on Wed night. The confidence on any of this is low and
subject to change, because the long wave pattern over the western
states is nearly featureless, with only light and variable wind at
500mb. On the positive side, there are no significant dry cold
fronts expected during the upcoming week. Messick



$$ is the U.S. government's official web portal to all federal, state and local government web resources and services.