368
FXUS66 KOTX 171850
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1150 AM PDT Wed Jul 17 2024

.SYNOPSIS...

Hot and dry weather will continue this week with widespread upper
90s and triple digit temperatures. Today there is chance of
thunderstorms across the region containing little to no rainfall.

&&

.DISCUSSION...

UPDATE...Issued red flag warnings for portions of Stevens and Pend
Oreille county as well as the southern Palouse and Snake River
area for this afternoon and tonight.

Today through Thursday night: Upper level ridge axis remains
positioned to the east, more or less over Northwest Montana. This
will allow for warm/hot southwest flow on the west side of the ridge
to persist and keep temperatures on the hot side. In addition this
provided southwest to northeast path will not only steer smoke in
from fires to the south but also weather disturbances such as the
one expected to bring low precipitation producing (dry)
thunderstorms today. This disturbance is visible on satellite
imagery as it spins counterclockwise over Western Oregon this
morning. Lightning will raise concerns for new fire starts across
the landscape. In addition, gusty outflow winds could result in fire
spread with any new starts. A Red flag warning is in effect for
several areas of North Central Washington Wednesday. Smoke from the
Pioneer Fire near lake Chelan as well as other local and regional
fires in Washington and Oregon will continue to impact air quality
hence air quality alerts remain in effect for a number of counties
in Washington and Idaho. /Pelatti

Friday to Tuesday: A rebounding ridge will bring mostly dry and
hotter conditions this period. However there will be at least a
couple features to watch that could alter this thinking. On Friday
one such feature is a shortwave disturbance that lifts through
the region, near the Cascades through north Idaho. However, unlike
the wave that pushes through today, the atmosphere Friday is very
dry. While there lapse rates remain steep, there is little if any
convective instability. Thus aside from a few more clouds and
some breezy conditions near the Cascade gaps and western basin,
this feature is expected to pass without precipitation chances. If
more moisture or instability can into the region then the forecast
would need changing, but confidence leans toward dry. The ridge
rebounds into early next week ahead of deeper low over the
eastern Pacific. Another disturbance skims by the Cascades Sunday,
but appears to weaken as it does. Then the offshore trough tries
to advance inland toward Monday and Tuesday of next week. Some
guidance does start to introduce some isolated shower chances with
it, but consistency from run-to-run and model-to-model still
supports a dry forecast. This too will have to be monitored should
the models start to trend with higher PoPs. The system should
come with increased winds, especially near the Cascades and
central WA, so with continued dry conditions we will have to
monitor this for critical fire conditions. Temperatures will be
the most notable thing aside from the fire weather concerns, as
highs push into the 100s for much of the weekend into next Monday
before trending down toward Tuesday. Saturday and Sunday may see
some dangerous heat too. /Solveig
&&

.AVIATION...
18Z TAFS: High clouds and smoke are passing through the region.
Downslope winds along the East Slopes of the Cascades will push
smoke from the Pioneer Fire down Lake Chelan into the Chelan and
Methow Valley airports this morning. Some minor visibility
reductions will also occur at the Lewiston airport with localized
smoke from Oregon. Small chance of thunderstorms overnight and
into Thursday morning for most TAF sites.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
With the exception of smoke near the Pioneer Fire and in Lewiston,
there is high confidence in VFR conditions.

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

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       100  65  98  64  98  66 /  20  20   0   0   0   0
Coeur d`Alene  98  63  95  63  96  63 /  10  20   0   0   0   0
Pullman        95  58  94  59  94  61 /  20  10   0   0   0   0
Lewiston      104  71 104  71 104  71 /  20  10   0   0   0   0
Colville       98  57  97  55  97  56 /  20  20   0   0   0   0
Sandpoint      95  60  93  58  94  57 /  10  20   0   0   0   0
Kellogg        96  67  92  68  94  69 /  10  20   0   0   0   0
Moses Lake    102  63 101  62 101  62 /  20  10   0   0   0   0
Wenatchee     101  71 102  70 100  70 /  20  20   0   0   0   0
Omak          104  67 103  66 103  66 /  20  20   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Heat Advisory until 11 PM PDT Thursday for Coeur d`Alene Area-
     Idaho Palouse-Lewiston Area.

WA...Heat Advisory until 11 PM PDT Thursday for Central Chelan County-
     Lower Garfield and Asotin Counties-Moses Lake Area-Okanogan
     Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-
     Waterville Plateau-Wenatchee Area-Western Okanogan County.

     Red Flag Warning until midnight PDT tonight for Lower Palouse  -
     Snake River (Zone 709).

     Red Flag Warning until midnight PDT tonight for Eastern Columbia
     Basin  -Palouse  -Spokane Area (Zone 708)-Western Columbia
     Basin (Zone 707).

     Red Flag Warning from 4 PM this afternoon to 2 AM PDT Thursday
     for Foothills of Northeast Washington (Zone 701).

     Red Flag Warning until midnight PDT tonight for Colville
     Reservation (Zone 702)-East Portion of North Cascades
     National Park/Lake Chelan National Recreation Area (Zone
     697)-East Washington Central Cascades (Zone 696)-East
     Washington North Cascades (Zone 698)-Foothills of Central
     Washington Cascades (Zone 705)-Methow Valley (Zone 704)-
     Okanogan Highlands and Kettle Mountains (Zone 699)-Okanogan
     Valley (Zone 703)-Waterville Plateau (Zone 706).

&&

$$