Area Forecast Discussion
Issued by NWS Pocatello, ID

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FXUS65 KPIH 241938
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
138 PM MDT Mon Jul 24 2017

.SHORT TERM...Convective temperatures have been reached over many
portions of central and eastern Idaho initiating rapid expansion
of thunderstorms this afternoon. Low pressure off the coast of
California is pushing a series of weather impulses through our
area through Thursday. Abundant moisture with precipitable water
amounts up to 1.00 inch will assist in locally heavy rainfall with
some of the thunderstorms. Expect gusty outflow winds as the main
impact concern with the thunderstorms through Thursday although
cannot rule out some small hail. Increasing cloud cover Tuesday
and Wednesday will reduce daytime highs some 10 degrees but keep
overnight lows warmer. Thus with increased moisture, muggy
conditions expected.

.LONG TERM...Friday through next Monday...the ridge of high
pressure begins to build again with temperatures warming back
into the 90s region-wide. There is a chance for an isolated
thunderstorm across the central Idaho mountains each day - with
forecast models showing a monsoon push next Monday. Timing though
is still a concern so will only increase chances marginally. VP


&&

.AVIATION...Monsoon moisture flowing into Idaho through Thursday
will result in scattered daily thunderstorm chances with gusty
outflow winds and small hail. Expect VFR conditions over most
flight areas except in and near convective activity. VP



&&

.FIRE WEATHER...Monsoon moisture will continue to pour into eastern
Idaho through the middle of the week. Showers and storms, including
overnight are forecast. The risk of gusty winds over 40mph will
persist through the period especially in the afternoon and evening
IF we can maximize instability. The risk of heavy rainfall increases
after today as deeper moisture arrives, for a mix of wet and dry
thunderstorms.  We will have to keep an eye out on burn scars for
any flooding/debris flow potential especially where stronger storms
form and slow storm motion. Our current round of Red Flag Warnings
across the central mountains (422 and 476), and the southern
highlands/Magic Valley (425 and 427) will remain in effect. Storms
have been a bit slow to develop and the morning model runs hinted at
lower instability. That said, we should see storm coverage increase
through sunset over the mountains. Scattered storms are expected in
the areas where the warnings are in effect, with more isolated
elsewhere. What develops over the Snake Plain is more dependent on
outflow boundaries. Will we see Red Flag conditions Tuesday? Right
now, that is very "conditional" or iffy based on the likelihood of
more cloud cover through the day and more steady rain across the
area. IF (we stress IF) we get good storms going, it would probably
be over the central mountains and the highlands south of Burley. For
the moment, we will not put out additional headlines for tomorrow
based on lack of confidence in this scenario. For Wednesday, we may
see a better chance of scattered storms over the mountains but we
will need to watch trends over the next 24-36 hours to see if that
comes to pass. We should see monsoon moisture thin out later this
week, but the tradeoff is warmer and lower humidity conditions
returning. Keyes

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM MDT this evening for IDZ422-425-427-
476.

&&

$$



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