587
FXUS66 KOTX 282140
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
240 PM PDT Tue May 28 2024

.SYNOPSIS...
A return of showers and thunderstorms today with a cold front
passage. A few storms could be strong with gusty outflow winds in
southeastern Washington and the Idaho Panhandle. Frosty conditions
is expected Wednesday night into Thursday morning. Cool and
showery conditions will continue through the end of the week with
drier and temperatures warming back up to near normal for the
start of the weekend.

&&

.DISCUSSION...
Today and tomorrow: Cloud cover and showers over Eastern
Washington this morning lasted much longer than anticipated. Low
level lapse rates are slowly improving this afternoon and showers
are becoming more vigorous in the Spokane area. The severe threat
is very low (less than 5% chance) for Spokane/Cda/Northern
Mountains thanks to the cloud cover. Far southeastern Washington
and the Camas Prairie have much steeper low level lapse rates
thanks to less cloud cover and more surface heating. Convective
inhibition has started to decrease in southeastern Washington and
the southern Panhandle over the last couple hours and cumulus
towers have been growing in northeastern Oregon. The best
cape/shear parameter space remains largely untapped and the cams
are still hinting at storms clipping the L-C valley, Camas
Prairie, and rural Shoshone County. The main timing remains now
through 10 pm for stronger cells. Storms are capable of large hail
(around an inch or so), damaging wind, and frequent lightning.

Wednesday looks showery and breezy, particularly through the Cascade
gaps and Columbia Basin. Temperatures tomorrow look around 10
degrees cooler with highs in the upper 50s and 60s. /Butler

Thursday and Friday: The trough continues to push east into the
northern high plains. A transient ridge will move into the Inland
Northwest providing a dry forecast and warming temperatures. Skies
will be mostly clear Thursday with clouds increasing Friday
afternoon ahead of the next weather feature. There will be some
breezy Cascade gap winds late Thursday afternoon and evening with
gusts to 25 mph.

Saturday through Monday: Clouds will continue to increase Saturday
with partly cloudy to mostly cloudy skies through the weekend as
weak troughing moves into the region. There is a 20-30% chance of
showers across the mountains of northern WA and the ID Panhandle
and a 15% chance of thunderstorms along the Canadian border. The
area for showers expands late Sunday afternoon and evening for the
entire region as a very large low pressure system in the Gulf of
Alaska begins to move south. There is a 40% of showers Monday and
that continues into Tuesday for the mountains.

It looks like a ridge will begin to build Wednesday onward with
the potential for the hottest temperatures so far this year
beginning next Friday the 7th and continuing through the weekend.
/Nisbet


&&

.AVIATION...
18Z TAFS: A cold front moving into the region will bring isolated
to scattered showers/thunderstorms and gusty winds. Convection
today will have relatively high cloud bases at 8 kft agl and
higher. Best chances for thunderstorms will be near KPUW and KLWS
this afternoon after 20Z with stronger convection expected to
develop to the southeast of these terminals. The rest of the
region east of a line of KMWH to KOMK will primarily see high
based convective showers that will have a less than 20% of
developing into a thunderstorm. A westerly pressure gradient will
tighten this afternoon with winds gusting as high as 30 kts
through the Cascades and across the exposed areas of the basin,
including all TAF sites. Expect convection to be pushing out of
the area to the east between 06-08Z this evening.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
Confidence is low that thunderstorms will impact airport terminals
today. Best chances of 20-30% will be in the afternoon after 21Z
for KGEG-KSFF-KCOE-KPUW-KLWS. There is less than a 5% chance that
thunderstorms will impact the KEAT and KMWH terminals today. /SVH

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

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        43  62  38  65  41  70 /  20  20  10   0   0   0
Coeur d`Alene  43  59  37  61  40  69 /  30  40  20   0   0   0
Pullman        42  57  37  61  40  67 /  50  20  20   0   0   0
Lewiston       50  66  44  69  46  77 /  60  10  10   0   0   0
Colville       37  59  31  65  35  71 /  40  70  10   0   0   0
Sandpoint      43  57  36  61  39  67 /  50  70  40  10   0   0
Kellogg        45  55  38  59  42  66 /  70  50  50   0   0   0
Moses Lake     42  67  38  72  41  75 /  10  10   0   0   0   0
Wenatchee      44  64  43  69  45  74 /  10  10   0   0   0   0
Omak           40  66  37  69  40  75 /  20  20   0   0   0   0

&&

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

$$