845
FXUS66 KOTX 292114
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
214 PM PDT SAT MAR 29 2025
SYNOPSIS
THIS WEEKEND WILL BE DRIER OVER THE REGION WITH SCATTERED SHOWERS
MAINLY OVER THE MOUNTAINS. ANOTHER ROUND OF MORE WIDESPREAD SHOWER
ACTIVITY SPREADS INTO THE REGION SUNDAY NIGHT INTO MONDAY, WITH A
COOL AND UNSETTLED WEATHER PATTERN PERSISTING THROUGH MUCH OF NEXT
WEEK.
DISCUSSION
TONIGHT THROUGH MONDAY NIGHT: SHOWERS WILL MAINLY AFFECT THE
MOUNTAINOUS TERRAIN THROUGH THIS AFTERNOON, WITH SOME POSSIBLE
SHOWERS IN THE LOWER ELEVATIONS BUT THOSE WILL DEPEND ON HOW MUCH
INSTABILITY IS AVAILABLE IN THE COLD POOL THIS AFTERNOON. SOME
GRAUPEL IS POSSIBLE IN THESE SHOWERS, BUT MOST IMPACTED WILL SEE
RAIN. SHOWER ACTIVITY WILL FADE THIS EVENING AS DAYTIME HEATING
DECREASES. ON SUNDAY, THE TROUGH WILL MOVE EAST, BRINGING A BREAK IN
THE SHOWERS AND SLIGHTLY WARMING TEMPERATURES. ON SUNDAY NIGHT, A
DEEP CLOSED LOW WILL TRACK TOWARDS THE OREGON COAST INTO MONDAY,
BRINGING ADDITIONAL SHOWERS FROM THE SOUTHWEST. MOST AREAS ARE
EXPECTED TO RECEIVE 0.10-0.30 INCHES, WITH SNOW LEVELS 3500-4500
FEET, RESULTING IN 1-3 INCHES OF SLUSHY SNOW OVER MOUNTAIN PASSES.
WITH THE HIGH SUN ANGLE AND MUCH OF THE SNOW FALLING DURING DAYTIME
TEMPERATURES, SNOW AMOUNTS COULD BE LESS DUE TO MELTING.
TEMPERATURES WILL WARM SUNDAY, WITH MID 50S TO LOW 60S EXPECTED
BEFORE COOLING AGAIN DOWN INTO THE 50S FOR MONDAY BEHIND THE SYSTEM
THAT MOVES SUNDAY NIGHT. /KK
TUESDAY-THURSDAY: COOL, HEIGHT ANOMALIES WILL BE OVER THE INW
THROUGH THIS PERIOD COURTESY OF A BROAD UPPER-LEVEL TROUGH. THIS
LEADS TO HIGH CONFIDENCE FOR NEAR TO BELOW NORMAL TEMPERATURES.
PRECIPITATION WILL BE MORE CHAOTIC AND SPRING-LIKE, DRIVEN BY
EMBEDDED LOW PRESSURE SYSTEMS (LOCAL ORGANIZED BANDS) OR SURFACE
HEATING (HIT OR MISS AFTERNOON SHOWERS). LOOKING AHEAD, THERE IS
MODERATE CONFIDENCE FOR MINIMAL WEATHER IMPACTS AT THIS POINT OF
TIME. MAIN THINGS TO MONITOR WOULD BE ISOLATED AFTERNOON LIGHTNING
AND POTENTIAL FOR WET SNOW ACCUMULATIONS ON THE MOUNTAIN PASSES
AND POSSIBLY SOME LOWLANDS DURING THE EARLY MORNING HOURS. IF YOU
HAVE NEEDS FOR DRY CONDITIONS FOR A RAIN SENSITIVE PROJECT, THIS
MAY NOT BE THE BEST TIMING AND FORECAST VALUES FOR POPS COULD
CHANGE DRASTICALLY FROM DAY TO DAY.
ONE LOW PRESSURE SYSTEM WILL BE OVER NE OREGON TUESDAY MORNING WITH
THE EXACT PLACEMENT FAR FROM CERTAIN. THIS WILL BE IMPORTANT
WHERE A DEFORMATION BAND SETS UP ON ITS NORTHERN PERIPHERY. TIME
OF DAY AND ACCOMPANYING 85H TEMPS ALSO SUGGEST POTENTIAL FOR WET
SNOW ACCUM DOWN TO 2000 FEET UNDER THIS BAND. THE TENDENCY WILL BE
FOR THIS BAND TO WEAKEN THROUGH THE DAY WITH WIDELY SCATTERED
CONVECTIVE SHOWERS FILLING IN THE LANDSCAPE. THERE IS NOT A LOT OF
CAPE TO SPEAK OF ON TUE SO LIGHTNING THREAT SHOULD BE MINIMAL TO
NONE.
BY WEDNESDAY AND THURSDAY, HEIGHTS BEGIN TO BUCKLE OVER THE E PAC
PLACING THE NORTHWEST UNDER NORTHWEST FLOW ALOFT. OVER 80% OF THE
MODELS SUPPORT ONE MORE SHORTWAVE DROPPING THROUGH THE REGION
BETWEEN WED AND THU. TIMING AND STRENGTH OF THIS WAVE COMES WITH
MODERATE UNCERTAINTY AND THERE IS A 50/50 SPLIT IN THE ENSEMBLES
OF THIS BRINGING PRECIPITATION OUTSIDE OF THE MOUNTAINS OR NOT.
THE AIR MASS WILL REMAIN COOL AND WILL NEED TO MONITOR TIMING AND
STRENGTH GIVEN THE POTENTIAL FOR SNOW DOWN TO 2000 FEET THROUGH
THE OVERNIGHT AND EARLY MORNING HOURS AND POTENTIAL FOR A SLUSHY
MORNING COMMUTE FOR SOME AREAS. MOUNTAIN PASSES WILL ALSO BE
IMPACTED WITH SNOW SHOWERS WITH IMPACTS MAINLY CENTERED AFTER
SUNSET AND BEFORE SUNRISE. NBM PROBABILITIES FOR 0.1" OF SNOW FOR
THE LOWLANDS IS PRETTY LOW FOR WEDNESDAY MORNING (< 10%) BUT
INCREASE BETWEEN 10-30% FOR THU FOR AREAS ABOVE 2000 FEET ON THE
NORTHERN AND EASTERN RIM OF THE BASIN AND INTO THE MOUNTAIN
VALLEYS.
TUESDAY AND WEDNESDAY WILL ALSO FEATURE BREEZY AFTERNOON WINDS FROM
THE WEST AND SOUTHWEST. SPEEDS OF 10-20 MPH ARE EXPECTED AT TIMES
WITH A 20-40% CHANCE FROM THE CASCADE GAPS, BASIN, TO PALOUSE ON
TUE AND 40-80% CHANCE ON WED. GUSTS WILL BE MORE IN THE 20-25 MPH
RANGE TUE AND 30-35 MPH WED WITH LOCALLY STRONGER SPEEDS AROUND
POMEROY,
FRIDAY THROUGH THE WEEKEND: THERE IS INCREASING CONFIDENCE FOR A
WARMING AND DRYING TREND WITH 80% OF THE 100 MEMBER ENSEMBLES
SUPPORTING A RIDGE AND RIDGE AXIS OVER THE INLAND NW. THE OTHER
20% SUPPORT A WARMING TREND BUT HAVE THE RIDGE AXIS SHIFTED
FURTHER EAST WITH SOUTHWEST FLOW AND POTENTIAL FOR PACIFIC
MOISTURE TO INFRINGE. FORECAST LEANS TOWARD A DRY SOLUTION OUTSIDE
A SMALL CHANCE ALONG THE CASCADE CREST BUT WITH NBM SHOWING 10%
CHANCES REGION-WIDE, BEST NOT TO RULE OUT THE 20% OF WETTER
SOLUTIONS. NONETHELESS, TEMPERATURES WILL BE MUCH WARMER THAN
THOSE BEING EXPERIENCED CURRENTLY WITH WIDESPREAD 60S AND 70S.
WHEN VIEWING THE PROBABILITY FOR 70F OR WARMER, HERE IS HOW THE
NBM NUMBERS LOOK AT THIS TIME: /SB
AVIATION
00Z TAFS: VFR CONDITIONS WILL PREVAIL. SHOWER CHANCES DEVELOP
THIS AFTERNOON, BUT COVERAGE WILL BE LESS THAN YESTERDAY, WITH
KGEG/KSFF/COE HAVING A 20% CHANCE OF SHOWERS.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: CUMULUS WILL THEN
DEVELOP OVER NE WASHINGTON, THE PALOUSE, AND THE ID PANHANDLE.
THERE IS LOW CONFIDENCE IN SHOWERS IMPACTING TAF SITES.
-----------------------
CONFIDENCE DESCRIPTORS:
LOW - LESS THAN A 30 PERCENT CHANCE
MODERATE - 30 TO 70 PERCENT CHANCE
HIGH - GREATER THAN A 70 PERCENT CHANCE
PRELIMINARY POINT TEMPS/POPS
SPOKANE 32 59 41 53 34 51 / 0 0 80 70 30 30
COEUR D'ALENE 32 59 39 53 34 50 / 0 10 80 80 40 50
PULLMAN 32 56 39 51 34 49 / 0 0 70 80 40 50
LEWISTON 37 63 44 56 39 55 / 0 0 50 80 40 30
COLVILLE 30 58 37 53 32 53 / 0 0 60 80 30 40
SANDPOINT 33 55 37 50 34 48 / 0 10 70 90 50 70
KELLOGG 34 55 40 49 36 45 / 0 10 70 90 50 80
MOSES LAKE 33 62 40 58 34 59 / 0 0 70 30 10 10
WENATCHEE 36 58 40 55 37 56 / 0 10 70 40 10 10
OMAK 34 60 41 58 36 58 / 0 0 70 70 20 20
OTX WATCHES/WARNINGS/ADVISORIES
ID...NONE.
WA...NONE.
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