251
FXUS65 KPIH 070905
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
305 AM MDT Tue May 7 2024

.SHORT TERM...Today and Wednesday
Another cold windy day is expected across eastern Idaho today. Highs
will likely top out only in the 40s today for most, although some
lower 50s may be realized in parts of the Snake Plain. Things are
looking up however as a drastic warm-up is expected beyond today.
Before we get there though, we`ll have more clouds, precip and wind
to contend with today. A Wind Advisory continues until later this
evening. As expected, winds have dipped below criteria this morning
but should pick back up over the next few hours and last throughout
the day. Precipitation today will be much more showery in nature
compared to the past few days but the highest PoPs will be across
the eastern highlands. Could see some rumbles of thunder there as
well but this isn`t likely to be the norm. Some additional light
accumulations of snow will be possible in the eastern highlands and
to a lesser extent into the central mountains. Another frost
advisory or freeze warning will be possible tonight and into Wed AM
as temperatures will remain below normal.

There area will remain in a cold N/NE flow aloft tomorrow but the
influence of the upper low will start to diminish somewhat and
throughout the day, we`ll see signs of the weather pattern starting
to transition. Temps will stay well below normal but will be warmer
than Tuesday while skies slowly start to clear out a bit from west
to east. Some high elevation PoPs will linger in the forecast on
Wednesday but we`ll have to wait until Thu before things noticeably
improve going forward. McKaughan

.LONG TERM...Thu through Mon
An upper level ridge-trough pattern, rotated 90 degrees clock-
wise sits over the Great Basin at the start. This has a dry, and
potentially cool east to northeasterly airflow. The trough
eventually becomes a close low over the southwestern states, with
more northerly airflow over the forecast area. It is weak flow and
continued dry by Fri. On Sun, the close low edges slowly
northward and may bring instability showers and thunderstorm on
Mother`s Day. On Mon, a trough from the coast moves through this
pattern and breaks it up, bringing showers and thunderstorms
again. The movement of the Sun low and the Mon trough are by no
means certain; the clusters indicate an extremely weak pattern
that sometimes has a discernible trough, sometimes no.

Temperature-wise, the clear skies and subsidence provides strong
warming with temperatures around climatic normals Thu night/Fri,
then continued warming to Sun with the onset of moisture and then
the approaching trough. All this does is level off the warm-up
starting Sunday, when Snake River plain/eastern Magic Valley highs
will be middle 70s to around 80. Breezy northeast wind on Thu
subsides during the middle period, then a west to southwest breezy
wind kicks in for Sun/Mon during the afternoons.
Messick


&&

.AVIATION...
VFR conditions in place across the area this morning although some
occasional lower CIGs may briefly impact terminals in and around
showers this morning. Precipitation today will be more showery in
nature so will maintain VCSH wording for much of the period given
the "hit-or-miss" nature of things. Winds remain the biggest impact
to aviation with another breezy day anticipated. KBYI and KPIH will
be the windiest locations but no one will be spared from winds
gusting 20+ kts throughout much of the daylight hours today, closer
to 40 kts at BYI and PIH though. Things slowly begin to improve as
we move into Wednesday with winds lessening and CIGs slowly
improving and precip diminishing a bit. McKaughan

&&

.HYDROLOGY...
Area rivers remain elevated today, with the Portneuf and
Blackfoot Rivers remaining the trouble spots of the day with Flood
Warnings continuing. Cool temperatures and ongoing periods of
showers (snow at higher elevations) will continue to slightly
mitigate snowmelt runoff. Periods of showers will continue to
provide additional water into the basins, mainly snow at mid slope
and higher elevations. Blackfoot River levels look to stay at
Minor Flood for the foreseeable future. Portneuf forecast trends
continue to produce a temporary nudge back close to the low-end
Moderate Flood category, then drop back into persistent Minor
Flood for several days. The cold temperatures and consistent
unsettled conditions should keep East Idaho waterways high, fast
and cold through the week. DMH

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 8 PM MDT this evening for IDZ051-054>057.

Frost Advisory until 9 AM MDT this morning for IDZ051>055.

&&

$$