000
FXUS65 KPIH 222021
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
221 PM MDT Mon Apr 22 2024

.SHORT TERM...Today and Tuesday.
Looking at satellite imagery our area remains under breezy
northwest flow aloft with a weak ridge axis just to our west.
Expect dry conditions, slightly cooler than normal conditions, and
breezy winds today. Wind gusts will range from 20 to 35 mph this
afternoon. Early Tuesday, the weak ridge axis moves over our area
then this ridge axis weakens as well as moves east by Tuesday
afternoon. Look for southwesterly flow to set up by Tuesday
afternoon bringing warmer temperatures, 8 to 12 degrees above
normal. Moisture ahead of an upper level low off the coast of
California will start to make its way into our southern areas late
Tuesday. There is a 10 to 20 percent chance of showers along the
Utah border late Tuesday afternoon into the evening.
Wyatt

.LONG TERM...Wednesday through next Monday.
An upper low will move onshore into southern California on
Wednesday with southwest flow aloft over Idaho filtering in warm
air and moisture. Daytime temperatures will warm to 10 or more
degrees above normal on Wednesday, with this being the warmest day
of the week. Highs will run in the low 70s across the Snake Plain
and eastern Magic Valley, with 60s in the highlands, and 40s and
50s in the mountains. Beginning Thursday, upper flow turns more
westerly as another Pacific Northwest system moves onshore.
Precipitation chances become increasingly widespread beginning
Wednesday, with isolated to scattered thunderstorms both Wednesday
and Thursday afternoons. The trough axis will shift overhead
early weekend with widespread PoPs of 50 percent and higher Friday
and Saturday. Temperatures will decrease by several degrees on
Thursday and by another 5 to 10 on Friday following a cold front
passage, with temperatures looking to remain fairly stable again
on Saturday before they begin to trend upward again. Beginning
Sunday, 500 mb ensemble clusters feature differences in the
amplitude of the trough and indicate much variation amongst models
regarding the timing of the next low working through the PNW and
a ridge building in from the southwest.
Cropp

&&

.AVIATION...
VFR conditions and dry conditions forecast areawide under FEW to
SCT clouds through Tuesday. Winds will remain breezy today at
KPIH, KIDA, KBYI, and to a lesser degree KSUN with sustained
southwest/west winds of 10 to 15 kts and gusts ranging 20 to 25
kt. Winds will decrease early this evening, becoming light
overnight into early Tuesday morning. Cloud cover and
precipitation chances increase early Wednesday through the
weekend.
Cropp

&&

.HYDROLOGY...No major changes in the hydro forecasts at this
time. Water levels on the Portneuf river continue to run high,
just below moderate flood stage for the Portneuf river in
Pocatello. The river forecast for the Portneuf river in Pocatello
shows the river running above flood stage for the foreseeable
future and likely climbing back to moderate flood stage by
Tuesday. At Topaz on the Portneuf, current levels remain very near
minor flood and are forecast to rise above minor flood stage by
late Tuesday into Wednesday. Thus, have upgraded the flood
advisory on the Portneuf at Topaz to a flood warning. Water levels
are forecast to slowly rise toward the end of the week with
warming temperatures through Wednesday and the return of
precipitation chances in the second half of the week into the
weekend.
Wyatt

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$