125
FXUS66 KOTX 280456
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
956 PM PDT Mon May 27 2024

.SYNOPSIS...
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 in southeastern Washington and the Idaho
Panhandle. Cool and showery conditions continue through the end
of the week with drier and warmer conditions at the start of the
upcoming weekend.

&&

.DISCUSSION...
Evening update: Upper level trough approaching the northwest
through Tuesday morning is producing elevated instability ahead of
it. As of 830 PM some thunderstorm activity was developing well
south of the region across Eastern Oregon. Several of the CAM`s
models are showing elevated convection increasing and moving north
into Tuesday morning as moisture and elevated instability lift
north. The main activity is shown by the CAM`s models to track
from the Tri-Cities area up through the Upper Columbia Basin,
Spokane area, and NE Washington into the North Idaho Panhandle,
mainly after midnight. POP`s have been increased to reflect the
latest NBM guidance. With Elevated CAPE of only 100-200 J/KG and
only weak atmospheric lift through the morning, confidence is low
on whether nocturnal thunderstorms will develop or not this far
north. But given there is some instability to work with have added
a slight chance for the overnight and morning hours for the
Ritzville, Davenport, Spokane, and La Crosse areas.

No changes to the afternoon or evening thunderstorm forecast on
Tuesday. The latest 00z CAM`s models show the best potential for
stronger storms over the mountains of NE Washington into the N
Idaho Panhandle, as well as over the Camas Prairie into Shoshone
county. JW

&&

.AVIATION...
06Z TAFS: A weather system will spread an increase chance for
showers and thunderstorms mainly east of a line from Moses Lake to
Republic into Tuesday. Elevated instability will help contribute
to showers developing between 9-18z mainly from the Tri Cities
area up through the Columbia Basin and NE Washington. There is a
20% chance of thunderstorms at KGEG/KSFF with this round of
convection, and a 10% chance at KMWH/KPUW/KLWS. Stronger storms
are possible Tuesday afternoon and evening, but confidence is low
on whether or not any of the TAF sites will be impacted. The most
likely areas are KGEG/KSFF/KCOE/KLWS with a 30% chance of
thunderstorms. The best chances will be over far NE WA/N Idaho
with a 40-50% chance at Colville, Sandpoint, and Bonners Ferry.
Locations south and east of Lewiston will also carry a 40-50%
chance of thunderstorms. A few strong storms are possible, but
none of the CAM`s models are showing strong convective gusts
impacting any of the TAF sites.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
There is high confidence for VFR conditions to continue across the
region. The one exception is under heavier showers or
thunderstorms where there is a moderate chance of visibility being
reduced to MVFR. 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        52  74  45  62  39  65 /  20  30  10  20  10   0
Coeur d`Alene  51  73  45  59  38  62 /  10  40  30  30  20   0
Pullman        52  71  44  58  37  61 /  20  40  40  10  20   0
Lewiston       57  80  52  66  45  70 /  10  40  60  10  20   0
Colville       45  73  38  61  31  66 /  10  70  40  60  20  10
Sandpoint      48  71  45  56  38  61 /  10  60  60  60  40  10
Kellogg        53  74  48  55  39  59 /   0  40  70  50  40  10
Moses Lake     53  78  43  67  39  72 /  10  20   0  10   0   0
Wenatchee      56  73  45  63  43  69 /   0  10   0  10   0   0
Omak           51  76  42  66  39  71 /   0  20  10  10   0   0

&&

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

$$