Rathdrum, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

462
FXUS66 KOTX 242230
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
330 PM PDT Sun May 24 2026

.KEY MESSAGES...

- A cold front on Monday will bring isolated thunderstorms to
eastern Washington and north Idaho for the late afternoon and
evening hours. A few storms may become strong southeast of a line
from Pullman to Coeur d`Alene producing hail up to the size of
nickles and wind gusts up to 50 mph. Cannot rule out an isolated
severe thunderstorm producing large hail and damaging wind gusts.

- There is a growing threat for thunderstorms Thursday and  Friday
with a 20-30 percent chance of being widely scattered across the
region. Some thunderstorms may be strong with a risk for hail, gusty
outflow winds, and heavy downpours.

&&

.SYNOPSIS...
Dry conditions with above normal temperatures will continue through
the weekend. A cold front on Monday will bring breezy to windy
conditions late in the day. The cold front will also bring showers
with a chance for thunderstorms especially in the Idaho Panhandle.
Cooler temperatures Tuesday into Wednesday. Widely scattered showers
with the potential for thunderstorms Thursday into Friday. Friday
will also be breezy to windy and cooling to near normal into next
weekend.

&&

.DISCUSSION...
This afternoon through Monday night: A strong upper level low
pressure system is establishing itself over the Gulf of Alaska
today. With it is a vigorous cold front pushing across 130W in
the eastern Pacific. Rounding the backside of the low is a 145
kt jet streak and this will act to deepen the trough with the
upper low diving south just off of the coastline of Washington
and Oregon. The trough elongating will slow the progression of
the cold front and this will result in warmer temperatures under
amble sunshine across extreme eastern Washington into the Idaho
Panhandle. High temperatures on Monday from the Palouse to
northeast Washington into the Idaho Panhandle will peak out in
the lower 80s, except for the Lewiston-Clarkston Valley warming
into the mid to upper 80s. A modest P-Wat plume along the front
increasing to between 0.8 to 0.9 inches will supply moisture to
go along an atmosphere that will become increasingly unstable
through the afternoon hours. Upper levels will only be slightly
diffluent over the region as the low approaches. Much of the
lift synoptically will come with strong dynamics along the front
itself. The cold front will interact with surface based CAPE
values up to as much as 1000-1500 J/kg based on the 00Z
deterministic model guidance. Model ensembles blend this out to
between 500-1000 J/kg and may be underplaying the potential
instability because of that. There will also be sufficient 0-6
km bulk shear to support the potential for organized convection
and even the potential for a few supercells. The probability of
thunderstorms is right around 30% over the southern to central
Idaho Pahandle decreasing to 10-20% into the Spokane Area and
Northeast Mountains.

The cold front will also bring a burst of moderately strong
wind gusts when pushes across the region late afternoon into the
evening between 5-10 PM. Wind gusts will be strongest across
the exposed areas of the Columbia Basin to the Palouse and
Lewiston-Clarkston Valley to between 35-45 mph expected. The
peak wind gusts of around 40-45 mph is expected to be short-
lived of up to an hour or two with the passage of the cold
front. Not quite reaching our criteria of meeting a wind
advisory but will be close.

The cold front will also bring a band of showers where the
atmosphere will be less unstable across north-central
Washington. Showers will bring pockets of more moderate to brief
heavy downpours. Thunderstorms that develop will also bring
brief heavy rain. The threat for flooding impacts is low on
Monday though since showers and thunderstorms will be moving
quickly. Cannot completely rule out blowing dust, but the
potential looks low with less in the way of point sources for
dust potential as we move into the tail end of the planting
season and the stronger wind gust that would carry dirt is
expected to be brief.

Here are the impacts that may occur with the weather system
tomorrow ranked according to risk potential:

(1) Damaging winds and large hail from thunderstorms. The
ingredients for seeing isolated severe thunderstorms is
apparent. The main question and uncertainty is if the atmosphere
will moisten up enough to realize CAPEs to around 1000 J/kg. If
so, then the probability for those 30% chances of thunderstorms
increases. An isolated supercell or two also cannot be ruled
out and that will come with the threat for rotation. The area
that will need to be monitored for stronger convection will be
from the Northeast Blue Mountains, across the Camas Prairie,
Palouse and into the Central Panhandle Mountains. This includes
the Lewiston-Clarkston Valley, Pullman/Moscow, St. Maries, and
the Silver Valley.

(2) Gusty westerly winds along the cold front in the early
evening that brings isolated tree damage/power outages, and a
small potential for narrow dust channels near any recently
worked fields. Difficult travel for high profile vehicles may
also occur, especially for any travel along I-90, U.S. 195 and
U.S. 95.

(3) Rapid spread of grass fires. This is a tertiary impact due
limited dry grassy fuels available to carry fire. However, we
have been getting more reports of smaller wildfires across the
region over the past week or so. There are areas out there that
will carry fire, and winds picking up before the rain arrives
will bring the risk for spreading wildfires quickly.

Other considerations with this cold front will be colder air
that moves in behind the front for backcountry enthusiasts
camping at higher elevations. Temperatures above 4,000 feet
will drop into the 30s Monday night. Light snow may also occur
near the Cascade crest.

Tuesday through Friday: The upper level low becomes cut off
from the Polar Jet by Wednesday into Thursday. Model ensembles
are in good agreement that the low will take up residence over
western Nevada. This is just far south enough for temperatures
to rebound after a cool Tuesday with highs in the 60s back up
into the 80s by Thursday. Once again, the warm above normal
temperatures will result in an unstable atmosphere with CAPEs
once again up to around 1000 to 1500 J/kg by Thursday. Only by
then, much more of the Inland Northwest will be unstable. The
synoptic regime will also look quite different than what we`ll
see on Monday. The low will be positioned in such a way that it
will draw moisture in from the east with origins tracing all the
way over to the Atlantic and Gulf of Mexico. This is typically
a much juicer source of moisture and models reflect this with
widespread surface dew points in the upper 50s to around 60
regionwide. Where uncertainty lies is where will the lift come
from to kick off convection? There is a hint of a shortwave
rounding the low and entering the region from the southeast late
Thursday. This would bring synoptic scale forcing to kick off
thunderstorms. Differential heating over the mountains will also
potentially kick off convection. Surface based CAPE values
north of 1000-1500 J/kg will bring the potential for rapid
growth of thunderstorms with strong updrafts. Shear will be
weak, but enough instability that strong to severe thunderstorms
will be in play. A greater threat will be the potential for
flash flooding with P-Wats of 1 inch and higher.

A shortwave push across the eastern Pacific on Friday will kick
out the cut off low. Additional showers and thunderstorms can
be expected then. There will be more steering flow which will
help with reducing the flash flood threat, but storms will still
contain very heavy rain. A cold front will also bring breezy to
windy conditions across the region on Friday with gusts
potentially as strong as 40-45 mph through the Cascades and out
into the Columbia Basin.

Friday night through Sunday: Next weekend looks to bring more
benign weather. We will continue to some showers with a 10-30
percent chance. Doesn`t look nearly as unstable with the cold
front on Friday ejecting out the juicy mid Atlantic P-Wat air.
Temperatures cool to around normal with highs in the mid 60s to
mid 70s. /SVH

&&

.AVIATION...
00Z TAFs: VFR conditions will continue through the period.
Breezy winds will decrease this evening. A cold front pushes
across the Inland Northwest late Monday afternoon. Winds will
increase across the region again later Monday morning to
afternoon. The front will bring widely scattered showers and
thunderstorms to the Idaho Panhandle along with gusty and
shifting winds. Some chances may start as early as 22Z Monday,
but better chances don`t arrive at TAF sites unntil after 00Z
Tuesday.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
High confidence in continued 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        50  81  46  63  45  73 /   0   0  60  10  20  20
Coeur d`Alene  50  81  48  62  46  72 /   0   0  50  20  30  20
Pullman        49  81  43  57  41  65 /   0   0  50  30  40  40
Lewiston       52  87  50  62  48  70 /   0   0  50  40  50  40
Colville       44  80  42  68  41  79 /   0   0  70  20  30  10
Sandpoint      48  79  47  63  45  73 /   0   0  50  20  50  20
Kellogg        48  85  48  61  46  72 /   0   0  50  20  50  30
Moses Lake     49  81  44  68  44  78 /   0   0  50   0  10  10
Wenatchee      55  77  49  67  50  79 /   0   0  40  10  10  10
Omak           51  79  47  68  47  81 /   0   0  70  60  10   0

&&

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

&&

$$