886
FXUS66 KOTX 292129
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
229 PM PDT Sat Jun 29 2024

.SYNOPSIS...
With the arrival of a upper level disturbance, expect an
increasing threat of showers and thunderstorms in the Cascades
this evening spreading into eastern WA into north Idaho
overnight. Winds will be breezy Sunday afternoon with a renewed
chance of showers and thunderstorms for northeast Washington and
north Idaho. Mountain showers and seasonal temperatures continue
through early next week, followed by drier and much warmer
weather by the end of the work week.

&&

.DISCUSSION...
Tonight into Sunday: A sharp shortwave aloft swings across the
Pac NW overnight into Sunday which will be the focus for scattered
showers with embedded thunderstorms across the region. Moisture
has been on the increase with pwats reaching near 1 inch across
the Columbia Basin overnight. Cumulus been bubbling over the
higher terrain of the northern Cascades to Selkirks and Panhandle
mountains this afternoon. Convection commences over the northern
Cascades by mid afternoon with a 30-50% chance of showers that
will track to the north-northeast with time through the evening.
Theres a 15-20% of embedded thunderstorms, leading to brief
downpours, gusty outflow winds and small hail. Diffluence
increases late tonight with a secondary band of elevated showers
(20-40%) developing across southeast WA, Palouse, toward Spokane
and Coeur dAlene and then spreading into north Idaho during the
early morning hours, in addition cant rule out nocturnal
thunderstorms with less than a 15% chance. Mid and high level
cloud cover will give way to a mild night with balmy lows in mid
50s to mid 60. For Sunday morning, morning showers will be found
across mountains. With daytime heating and increase of
instability, convection will be renewed across northeast WA into
north Idaho with a 30-60% of showers and a 20-30% of thunderstorms
especially closer to the BC border. In the wake of the passing
disturbance, breezy west to southwest winds spread from the lee of
the Cascades, across the Columbia Basin to the Palouse with local
gusts of 25 to 30 mph. Daytime temperatures should be a few
degree cooler than today, although still mild.

Sunday night into Monday: A broad upper trough remains over the
region. Convection across northeast WA and north Idaho decrease by
Sunday evening with clearing as breezy winds subside as well.
Overnight lows cool back into the 50s. Monday will start off
mostly sunny and cumulus build up develop across northeast WA into
north ID as a weaker shortwave ripples through the area Monday
afternoon with a 30-60% chance of showers and a 15% of embedded
thunderstorms. Expect little change with daytime temperatures,
still remaining mild in the mid 70s to mid 80s and local westerly
wind gusts of 20 to 25 mph. /rfox.


Tuesday through Friday: The main story through next week will be a
ridge of high pressure slowly nudging eastward into our region from
off the Pacific. Mountain showers and thunderstorms will pop up each
afternoon Tuesday through Thursday due to some lingering moisture
and instability, but by Friday the ridge will have moved far enough
inland that chances for storms will be near zero regionwide.

Winds will pick up each afternoon and will calm back down after
sunset. Skies will generally be clear with the exception of
recurring afternoon cumulus development over the North Cascades and
Northeast WA/the North ID Panhandle.

Daytime highs will start out right around seasonal norms in the
upper 70s and low 80s Tuesday and Wednesday. Toward the end of the
week we`ll see a warming trend with highs reaching the upper 80s to
mid 90s by Friday. The current Fourth of July forecast is looking
sunny and warm with light winds and highs in the mid 80s to low 90s.
A slight chance of showers and thunderstorms will remain for
Boundary and Northeast Pend Orielle counties into the early evening,
but any lingering storms are expected to fizzle out after that.
/Fewkes

&&

.AVIATION...
00Z TAFS: Mid and high level clouds will continue across the TAF
sites through the period with VFR conditions and light winds with
speeds under 10kt. There is a 30-50% of showers with 15% of
thunderstorms through 8z, then a second band of elevated showers
creeps across the Palouse and north Idaho between 09z-15z with
the threat of light showers and a less than 10% of lightning.
Showers (50-60%) linger over the Idaho Panhandle through 18z.
Another round of showers and thunderstorms will be focused across
northeast WA and the northern ID Panhandle Sunday afternoon.
/rfox.


FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
High confidence in VFR conditions at our airport through the
period. General aviation pilots will need to monitor radar for
showers and thunderstorms through the evening and Sunday. There
is a low chance of thunderstorms this evening and overnight at the
TAF sites. /rfox.

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

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        60  80  54  80  54  81 /  30  20   0  10   0   0
Coeur d`Alene  59  77  53  76  52  77 /  50  40  10  10   0   0
Pullman        57  77  52  75  51  77 /  50  30   0   0   0   0
Lewiston       67  85  61  85  59  87 /  40  30   0   0   0   0
Colville       53  76  46  77  45  79 /  20  70  30  40  10  10
Sandpoint      55  72  50  73  49  75 /  30  70  30  50  20  20
Kellogg        59  72  55  72  54  74 /  60  70  20  20  10  10
Moses Lake     61  86  55  86  54  86 /  10   0   0   0   0   0
Wenatchee      63  82  60  81  57  84 /  20   0   0   0   0   0
Omak           60  85  55  84  54  87 /  20  10   0   0   0   0

&&

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

$$