Area Forecast Discussion
Issued by NWS Pocatello, ID

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FXUS65 KPIH 261923

Area Forecast Discussion
National Weather Service Pocatello ID
123 PM MDT Wed Jul 26 2017

.SHORT TERM...Tonight through Thursday night. Upper low over
northern CA today. Mid-level dry slot working through Great Basin
ahead of low into East Idaho with good clearing. Showers continue
over eastern highlands early this afternoon with a few embedded
thunderstorms. Air mass within clearing behind mass of showers
showing signs of destabilization again, and expect another round
of thunderstorms to develop this afternoon/evening across the
region. Models continue to have a difficult time with placement of
convection, but HRRR consistent this morning on rather widespread
swath of convection redeveloping between 2 and 4pm, shifting
northeast through early evening. Strongest cells in HRRR over
higher terrain regions so concentrated precip chances there. Upper
low opens and shifts northeast through Thursday, sliding across
East Idaho during the afternoon and early evening. Better shear
associated with passage of the shortwave could lead to slightly
more organized convection, so have reserved highest precip chances
for Thursday afternoon. As shortwave axis shifts east overnight,
expect precip to drop off significantly after midnight. DMH

.LONG TERM...Friday through Wednesday. Upper ridge rebounds
slightly heading into the weekend with resurgence of high pressure
over the Great Basin. Plenty of moisture lingers through the
remainder of the week, and thus have kept some chance of
convection each afternoon and evening through the period. Look for
temperatures to rebound back into the 90s for lower elevation
areas by Saturday, continuing into next week. DMH


.AVIATION...Monsoon moisture will continue to invade eastern Idaho
through tomorrow.  TAFs contain -SHRA VCTS or VCTS through this
evening, with the potential of heavy rain and gusty winds over
25kts. We can`t rule out small hail either. We went with VCSH
overnight as instability decreases BUT it does appears the potential
for showers and even thunderstorms is there overnight. More of the
same tomorrow. Overall, expect VFR although with storms containing
heavier rain ceilings and visibility COULD drop into MVFR. Keyes


.FIRE WEATHER...We are seeing clearing slowly from west to east
today with showers and isolated/widely scattered storms continuing
or redeveloping back to the west. Gusty winds and locally heavy rain
(over 0.25") are possible with stronger storms. Small hail is also
possible. With the next storm moving into our area later tonight and
Thursday, the risk of lightning/thunderstorms will persist into
tonight and obviously tomorrow.  Heavy rain is still possible
overnight and Thursday, with perhaps a little better chance of gusty
winds or small hail tomorrow. At the moment, coverage SHOULD still
remain below scattered. As mentioned over the past couple of days,
advanced warning on scattered coverage and Red Flag conditions could
be pretty short as we`ve been nowcasting (a few hours ahead of time
vs 12+ hours) areas of clearing and storm development. Heading into
the weekend, the models are still a bit chaotic (in other words, no
major agreement) in terms of storm coverage after Saturday. We are
expecting isolated Friday and Saturday as no real trigger is there
plus lack of deeper moisture. The ridge tries to rebuild northward
and the extent of that will determine how much moisture rotates
around the center of it and where it will go. We may easily be back
into the Monsoon soup early next week depending on how things pan
out. Keyes



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