Lewiston, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

015
FXUS66 KOTX 110905
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
205 AM PDT Wed Jun 11 2025

.KEY MESSAGES...

- Dry and breezy with elevated to critical fire weather concerns
  through Thursday.

- Cooler but still warm and mountain thunderstorms mid to late
  this week.

&&

.SYNOPSIS...
Breezy winds and dry conditions through Thursday will lead to
increased fire weather concerns. Temperatures continue to
gradually cool down for the rest of the week. Mountain
thunderstorm chances begin to increase Wednesday.

&&

.DISCUSSION...
Today and Tonight: We will tracking two shortwave disturbances in
the westerly flow. The first is a shortwave that is currently
pushing into southeastern Oregon early this morning. Out ahead of
this disturbance is scattered showers with embedded thunderstorms.
Instability parameters aren`t as unstable this far north into
southeast Washington into the Central Panhandle Mountains. We will
see mid level clouds developing with a small chance for a passing
light showers or sprinkles, but unlikely to see enough vertical
development for thunderstorms over our region this morning.

Diurnal heating this afternoon with destabilize the lower levels of
the atmosphere across the northern mountains and over the Camas
Prairie to the Idaho Panhandle closer to the Montana border. There
is also a considerable amount of CIN at between 60-100 J/kg. That is
a lot to lift air parcels up to reach their level of free convection
(LFC). The shortwave pushing from eastern Oregon into central Idaho
isn`t going to do the trick for the Inland Northwest; but, there is
a second shortwave disturbance that is racing across the eastern
Pacific and is progged to push into the Northwest late this
afternoon into this evening. There will be enough moisture and
instability for convection to get going over the northern mountains
with this disturbance. The general area will be from the Pasayten
Wilderness/Methow Valley and Okanogan Valley/Highlands late in the
afternoon and then migrate eastward with time through the evening.
Moderately steep mid level lapse rates with modest dynamics with the
shortwave will keep convection going into the night. Thunderstorms
will have rain with them, but it`s been so dry of late that any
lightning will have the potential to start new fires even when
containing rainfall.

In addition, winds will once again increase through the Cascade gaps
late this afternoon and become gusty. A deepening marine layer with
the incoming shortwave disturbance will facilitate a stronger push
of westerly winds across the Cascades than what was observed
yesterday. Expect wind gusts of up to between 25-30 mph across the
Wenatchee Area, onto the Waterville Plateau, and into the western
Columbia Basin picking up between 4 to 6 PM in the evening. Winds
will be a little breezy across the exposed areas of the basin as
well with gusts up to around 20 mph between Ritzville to Spokane and
Pullman for the afternoon hours. See the Fire Weather Section below
for more details on the winds and lightning and concerns pertaining
to fire weather.

Thursday through Sunday night: An upper level low pressure system
will hang out over the Gulf of Alaska just off of the BC coastline
at the end of the week. A serious of weak shortwave disturbances
will round the low push across the Northwest. There will be a
limited amount of moisture and modest instability. Best chances of
convection at around a probability of 25% will be near the Canadian
border along the northern mountains. Otherwise, it will be too dry
extending out into the Columbia Basin for convective showers to
form. Each disturbance that rounds the low will reinforce the
onshore flow across the Cascades with additional surges of westerly
winds for the afternoon and evening hours. Thursday will be a breezy
day for the whole day, which will be different than what we have
been seeing with the winds picking up later in the day. Temperatures
will be cooling, which will help to modify the low relative
humidity. Temperatures continue to cool Friday into Saturday with
highs in the 70s to low 80s; cooler, but still remaining above
normal for mid June. Breezy westerly winds continues as well, but
not as breezy as Thursday.

Monday through Tuesday: The latest ensemble clusters are highlighting
the scenario of the low nudging closer to the Northwest but looking
to remain just off to the northwest. There is still around a 10
percent chance that the low will see further digging and for a
deeper low that increase our chances for more widespread wetting
rains, but this scenario is an outside chance at best now. There is
a 30-40 percent chance for some light rain that favors the northern
mountain zones, but the leading scenario is for continued dry
conditions and above normal temperatures into early next week. /SVH

.FIRE WEATHER...
A red flag warning remains in effect for the Wenatchee Area,
Waterville Plateau, and Moses Lake Area for breezy winds and low
relative humidity Wednesday afternoon/evening. The cross-Cascade
pressure gradient is progged to be between 9-10 mb, whereas Tuesday
the gradient topped out at 8 mb. It will be a little stronger due in
part to a deeper marine layer on the west side of the Cascades.
Unfortunately, the marine layer won`t get deep enough to bring a
surge of cooler more moist air with relative humidity seeing a sharp
recovery. Expect critical fire weather conditions for the
aforementioned areas again today between 3pm and 9pm.

An additional elevated fire weather risk will be for lightning
starting new fires across the northern districts. Chances have
increased for thunderstorms to develop over the Pasayten Wilderness
to the Okanogan Highlands around 1500 PDT and then continue through
the evening into the overnight hours. Thunderstorm development looks
to be further east with time overnight and forming over the
mountains of northeast Washington by midnight. Lightning coverage
looks to be isolated to scattered. Better potential for scattered
lightning strikes will be in the afternoon to evening hours and then
decrease in intensity overnight. /SVH

&&

.AVIATION...
12Z TAFS: VFR conditions will prevail. Northwest winds late
Wednesday afternoon at KEAT will bring gusts up to between 25-30
kts. Winds will be breezy with out of the west-southwest
between 10-15 kts at KMWH-KGEG-KSFF-KCOE-KPUW.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
for VFR conditions. Conditions will be right for critical fire
weather conditions in the afternoon near KEAT to KWMH that may
result in fires that impact these terminals.

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

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        86  54  81  52  77  51 /   0  10   0   0  10  10
Coeur d`Alene  86  54  81  53  78  51 /   0  10   0  10  10  10
Pullman        82  49  77  49  74  46 /  10   0   0  10  10  10
Lewiston       91  58  87  58  83  56 /  10   0   0  10  10  10
Colville       87  49  81  46  77  44 /  10  30  20  20  20  20
Sandpoint      85  54  80  52  77  49 /  10  20  10  10  20  20
Kellogg        83  56  78  56  75  54 /   0  10  10  20  20  20
Moses Lake     93  56  87  50  82  50 /   0   0   0   0   0   0
Wenatchee      93  61  84  55  81  54 /   0   0   0   0   0   0
Omak           93  58  85  51  80  51 /  10  30  20  20  10  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Red Flag Warning from 2 PM this afternoon to 8 PM PDT this
     evening for Foothills of Central Washington Cascades
     (Zone 705)-Waterville Plateau (Zone 706)-Western Columbia
     Basin (Zone 707).
ID...None.

&&

$$