002
FXUS66 KOTX 271032
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
332 AM PDT Mon May 27 2024

.SYNOPSIS...
Dry and mild conditions on Monday with temperatures warming back
into the 70s. Tuesday will see a return of showers and
thunderstorms to Eastern Washington and Idaho Panhandle. A few
storms could be strong with gusty outflow winds. Cool and showery
conditions continue through the end of the week with drier and
warmer conditions at the start of the upcoming weekend.

&&

.DISCUSSION...
Memorial Day: The short lived ridge will begin to breakdown as the
next system begins to press into the coast. The Inland Northwest
won`t experience too many impacts through the day. Starting in the
afternoon, increasing  mid to high level clouds will filter through
the region. Winds will increase slightly in the afternoon with gusts
into the low 20s MPH for the Basin and Okanogan Valley. Areas of the
Blues Mountain and Northern Washington could have an isolated shower
late evening to overnight. Highs for the day will be in the 70s and
low 80s. Overnight lows will be in the 50s.

...STRONG THUNDERSTORMS POSSIBLE TUESDAY AFTERNOON AND EVENING...

Tuesday: The morning will start with prefrontal shower activity over
portions of Eastern Washington and Idaho Panhandle. It will bring a
few hundredths of precip to the area. This and the cloudy sky
conditions could inhibit some potential impacts for the cold front
passage over the afternoon and early evening by limiting how high
the max temperatures reach. The timing of thunderstorms will be
around 1 PM to 8 PM. BAsin areas are expected to have gusty winds
into the 30s with the frontal passage. Highs for the day are
expected to be in the 70s to low 80s. Overnight lows will be in the
upper 30s to 40s.

Ensembles continue to show an unstable atmosphere with the frontal
passage especially over the eastern third of Washington and the
Idaho Panhandle. Probability of at least 300 J/kg of cape is at
least 40%. The lower Idaho Panhandle has some areas reaching near
1000 J/kg. These areas have 0-6km shear (near 50 MPH), Lifted Index
(-1 to -3), and lapse rates (-7 C/kg). These are favorable for
thunderstorm development. Currently the Storm Prediction Center has
these areas under a general to marginal thunderstorm outlook.

For impacts, these areas can expect lightning, small hail, brief
downpours, and gusty winds. The areas with the best potential for
the strongest thunderstorms are Southeast Washington and the Idaho
Panhandle south of I-90. These areas have the higher probability of
strong thunderstorms. The main concern is the strong mid level winds
(50+ MPH) reaching the surface from the thunderstorms. Precipitable
water values have slightly increased from previous trends to near
one inch. It has led to an increase in the large hail of 1"
potential though still low. The period will continue to be
monitored and fine tuned as it nears. /JDC

Wednesday through Sunday: As an upper-level trough sweeps through
the region from west to east, temperatures will cool into the 60s
and low 70s for Wednesday and Thursday. Chances for showers and
isolated thunderstorms will remain in the forecast Wednesday along
the periphery of the Inland Northwest (over the Cascade Crest,
along the Canadian border, and throughout the ID Panhandle down to
Lewiston), though a lack of shear and decreased moisture in the
atmosphere will keep any storms that develop weaker than those
we`re expecting on Tuesday. Lightning, brief downpours, small
hail, and wind gusts of 30 to 40 mph will be possible. Cold air
aloft will allow for snowfall down to 4000 feet Wednesday morning,
so anyone planning on hiking or recreating in the mountains
should dress accordingly.

The upper-level trough will continue moving eastward through the
day on Thursday, making room for a ridge of high pressure to slide
onshore and take its place. Northeastern WA and the ID Panhandle
will see one last afternoon of showers and weak thunderstorms
before the ridge brings dry conditions regionwide. By Friday
evening the ridge will be centered over us keeping us dry and warm
heading into the first weekend of June. Just how strong the ridge
will be and how long it will stick around remains uncertain at
this point. /Fewkes

&&

.AVIATION...
06Z TAFS: High pressure will build in overnight into Monday with
passing mid and high clouds. VFR conditions will occur through 06z
Tuesday. Weather changes arrive late Monday night into Tuesday for
an increasing chance of showers and thunderstorms over eastern
Washington and north Idaho along with breezy winds.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
There is high confidence for VFR conditions to continue across
the TAF sites. JW

-----------------------

Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance

For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https:/www.weather.gov/otx/avndashboard

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        73  51  76  45  63  39 /   0  10  20  20  20  20
Coeur d`Alene  72  51  74  46  61  39 /   0  10  30  40  30  30
Pullman        72  52  72  44  59  38 /   0  10  10  50  10  20
Lewiston       81  57  80  52  68  46 /   0  10  20  60  10  20
Colville       73  45  73  39  62  33 /   0  10  60  40  60  30
Sandpoint      70  49  72  45  57  38 /   0  10  50  70  60  50
Kellogg        70  54  75  48  56  41 /   0  10  30  70  40  40
Moses Lake     78  53  78  44  68  40 /   0  10   0   0   0   0
Wenatchee      76  56  74  46  64  44 /   0   0  10   0  10   0
Omak           76  51  76  42  68  39 /   0  10  20  10  20   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$