740
FXUS66 KOTX 292011
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
111 PM PDT Tue Sep 29 2026

.KEY MESSAGES...

- Breezy west to southwest winds may result in patchy blowing
  dust near recently plowed fields Tuesday afternoon into the
  early evening.

- Mild and dry pattern this week, except for rain near the
  Cascade crest and chance of rain North Idaho Panhandle on
  Tuesday.

&&

.SYNOPSIS...
Moisture off the Pacific will bring rain to the Cascade crest
and northeast Washington and north Idaho mountains through
Tuesday evening. Temperatures will be near normal through the
middle of the week and then trend to above normal for the end of
the week and into the weekend.

&&

.DISCUSSION...
Tuesday night through Wednesday night:The Pacific Northwest will
remain under strong westerly flow through early Wednesday morning,
driven by a 120+ kt jet streak over southern British Columbia. As
the jet sags slightly southward tonight, 250 mb winds across
northern Washington and the Idaho Panhandle will increase to 100+
kts, sustaining gusty winds along mountain ridges through the night.
 Meanwhile, drier air filters into the northern valleys tonight into
Wednesday morning clearing clouds for much of Wednesday. The jet
begins to slowly lift northward and weaken Wednesday night into
Thursday with moisture also migrating back northward ahead of a weak
weather system approaching the Pacific Northwest. Before the
moisture lifts northward, clear skies and light winds early
Wednesday night will allow low temperatures across the northern
valleys to plummet into the 30s. Uncertainty exists in how quickly
the temperatures can decrease before cloud cover increases again
overnight, which will limit the radiative cooling. Currently, the
National Blend of Models gives Deer Park 20% chance for temperatures
below 36F.

Thursday through Monday: A warming trend will develop heading into
the weekend as an upper-level ridge builds across the western US.
Flat zonal flow will persist initially over the Inland Northwest
Thursday and Friday with weak weather systems moving through
Thursday and Friday. Outside of a small chance (20%) for light rain
showers across the north Cascades both days, these systems will
primarily result in increased cloud cover for the rest of the Inland
Northwest.  Ensembles are in good agreement for the ridge to become
established over the Pacific Northwest this weekend, initiating a
prolonged period of dry weather and above normal temperatures.
Beyond Monday, ensemble consensus favors persistent upper-level
ridging remaining in place through the first week of October.
However, 25% of ensembles show the ridge to be weak enough to allow
for weather systems to flatten it by the middle of next week, but
this is an unlikely scenario at this point. /vmt

&&

.AVIATION...
18Z TAFS: Mid and high clouds are encompassing the Inland
Northwest under a moist westerly flow. This strong westerly flow
will promote lee waves and favorable pattern for turbulence
with gusty winds surfacing in the lowlands by Tuesday afternoon.
A band of light rain showers is draped across southeast
Washington into the central Idaho Panhandle. Models keep flight
categories VFR through much of the day, with ceilings dropping
below 5000 ft across Shoshone County this afternoon. Overnight
today, models suggest ceilings to lower to 4000 ft or less, with
a 30% chance for ceilings below 3000 ft at KCOE after 9-12Z.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
for VFR conditions and breezy winds at all TAF sites today.
Moderate to high confidence for winds to remain steady through
the evening and overnight hours with lower confidence for
continued gusts. There is low confidence for MVFR ceilings to
develop across southeast Washington into the central Idaho
Panhandle after 09Z. There is a 30% chance at KCOE after 09-12Z,
but this was too low of confidence to include in the TAF at the
moment.

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

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        47  67  43  68  45  71 /  10   0   0   0   0   0
Coeur d`Alene  49  65  44  66  46  69 /  10  10   0   0   0   0
Pullman        48  64  44  68  45  71 /  10   0   0   0   0   0
Lewiston       54  70  49  73  51  76 /   0  10   0   0   0   0
Colville       39  66  36  68  38  70 /  10   0   0   0   0  10
Sandpoint      44  63  41  64  42  67 /  30  10   0   0   0  10
Kellogg        48  61  44  65  45  68 /  50  20   0   0   0   0
Moses Lake     46  70  45  72  46  74 /  10   0   0   0   0   0
Wenatchee      50  69  51  69  53  73 /  10   0   0   0   0   0
Omak           41  68  44  68  45  72 /  10   0   0   0   0   0

&&

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

&&

$$