FXUS66 KOTX 310523 RRA
AFDOTX
Area Forecast Discussion
National Weather Service Spokane WA
1017 PM PDT Wed Oct 30 2024
.SYNOPSIS...
Precipitation chances will spread into central and eastern
Washington today. A slow moving system will produce periods of
rain and mountain snow through Friday. Next week will remain
active with additional chances for precipitation and lowering snow
levels with snow in the mountains.
&&
.DISCUSSION...
Today through Friday: We are transitioning to a wetter pattern
today as the shortwave ridge shifts into western Montana. A deep
shortwave trough coming on the Pacific coastline this afternoon
will bring soaking rains and mountain snow to the inland northwest
over the next few days. Thanks to deep southerly flow, places in
central Washington that have not seen rains since August will even
receive wetting rains from this system. There will be a bit of a
break in the precipitation tonight and into tomorrow, but another
shortwave will pivot towards the Washington coast tomorrow and
bring back precipitation chances in the afternoon. This shortwave
will move fairly slowly onshore overnight Friday into Saturday.
Some snowflakes may mix into the rain in northeast Washington
Friday morning but am not expecting any accumulations.
Probability of 0.5” of rain or more now through Saturday morning:
Spokane: 75%
Wenatchee: 70%
Moses Lake: 90%
Lewiston: 55%
Deer Park: 90%
Sandpoint: 80%
Probability of snowfall amounts (4”, 8”, 12”) now through Saturday
morning: Washington Pass: 100%, 70%, 50% Stevens Pass: 100%, 40%,
10% Loup Loup Pass: 100%, 75%, 55% Lookout Pass: 40%, 20%, 5%
Sherman Pass: 100%, 60%, 40% /Butler
Saturday through Wednesday: Precipitation will linger in the region
Saturday morning, shifting focus to the ID Panhandle as an upper-
level low moves east. By Sunday, the low will mostly exit, leaving
limited precipitation in the higher terrain like the Cascade Crest
and northern ID Mountains. A shortwave will bring dry conditions to
eastern Washington from Sunday into Monday.
However, another disturbance from BC will bring another round of
widespread rain by Tuesday and Wednesday, though the timing and
track remain uncertain. Snow levels continue to stay between 3,000
and 4,000 feet, leading to mountain snow and valley rain, with a
potential for a rain/snow mix in the early morning temperatures in
the northern valleys. Afternoon highs will be in the 40s to low 50s,
while morning lows range from the 20s and 30s. Fog is likely where
skies clear overnight. /KM
&&
.AVIATION...
06Z TAFS: A weather system will move into central WA this evening
and spread eastward during the overnight hours. Light rain will
result in widespread MVFR/IFR conditions from now through Thursday
morning. The chances of rain have generally ended over central WA
for the night. Whether or not stratus develops once the rain ends is
the big question. For locations such as GEG-SFF-COE it seems likely
that the clouds will develop and persist through early afternoon.
Satellite is also showing widespread low clouds forming over central
WA and given an increasing offshore flow and limited mixing this
could be even harder to scrub out. The next shot of rain will move
in from the SE for the very end of the next TAF forecast.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
High confidence for MVFR conditions with the rain tonight into
tomorrow. Moderate confidence for IFR conditions tonight into
tomorrow. Low confidence as to when the stratus/low clouds will
break up once forming.
-----------------------
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 36 47 34 45 35 46 / 90 70 80 90 90 90
Coeur d'Alene 35 45 32 44 35 45 / 80 90 80 90 90 90
Pullman 33 46 33 44 34 43 / 80 70 80 90 90 90
Lewiston 40 52 39 52 40 51 / 80 70 70 80 80 90
Colville 32 45 28 43 26 44 / 90 80 80 90 90 90
Sandpoint 31 42 31 41 32 42 / 70 90 80 80 90 90
Kellogg 36 42 33 44 36 42 / 70 100 80 90 90 90
Moses Lake 33 50 36 48 35 50 / 90 40 90 90 90 70
Wenatchee 35 47 37 44 37 49 / 80 40 90 90 80 60
Omak 36 50 35 48 35 51 / 90 50 80 80 80 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Winter Weather Advisory until 11 PM PDT Friday for Okanogan
Highlands-Western Okanogan County.
&&
$$