590
FXUS66 KOTX 180518
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1018 PM PDT FRI APR 17 2026
KEY MESSAGES
- WARMING AND DRYING TREND FRIDAY THROUGH MONDAY.
- INCREASING RAIN SHOWER CHANCES MIDDLE OF NEXT WEEK.
SYNOPSIS
WARMER AND DRIER CONDITIONS RETURN FRIDAY THROUGH THE WEEKEND.
NEXT ROUND OF SHOWERS IS EXPECTED FOR THE MIDDLE OF NEXT WEEK.
DISCUSSION
TONIGHT TO MONDAY: A RIDGE OF HIGH PRESSURE AMPLIFIES OVER THE
REGION, WHILE LOW PRESSURE DEEPENS OFF THE PACIFIC COAST,
LEADING TO MOSTLY DRY CONDITIONS AND A WARMING TREND. THIS
AFTERNOON CUMULUS BUILD-UPS ON THE UNSTABLE BACKSIDE OF AN UPPER
TROUGH WILL GRADUALLY DISSIPATE, LEAVING MOSTLY CLEAR SKIES. A
LINGERING SHOWER THREAT NEAR THE IDAHO PANHANDLE MOUNTAINS WILL
LIKEWISE DISSIPATE. A WEAKENING MID-LEVEL SHORTWAVE SLIPS INTO
THE BUILDING RIDGE LATER TONIGHT INTO SATURDAY, CARRYING IN
SOME MIDDLE TO HIGH CLOUDS. OTHERWISE LOOK FOR DRY WEATHER, WITH
MINIMAL AFTERNOON BREEZINESS. LOWS TONIGHT WILL LARGELY BE IN
THE 30S, WITH SOME 20S OVER THE MOUNTAIN AND SHELTERED EASTERN
VALLEYS. HIGHS WILL BE IN THE 60S SATURDAY, WITH LOWS IN THE 30S
TO MID-40S. HIGHS WARM INTO THE 70S SUNDAY AND MONDAY, WITH
SOME LOW 80S IN THE DEEPER BASIN, WHILE LOWS ARE FORECAST TO BE
IN THE 40S TO LOW 50S.
TUESDAY TO FRIDAY: ENSEMBLES ARE IN GOOD AGREEMENT WITH THE
DEPICTION OF THE LOW PRESSURE OFF THE CA/OR COAST SHIFTING
EAST-NORTHEAST TOWARD THE NORTHERN ROCKIES/GREAT BASIN
AREA, BEFORE A RIDGE STARTS TO FLOP BACK IN TOWARD THE LATTER
PART OF NEXT WEEK. THIS WILL MEAN INCREASING PRECIPITATION
CHANCES STARTING TO EMERGE OVER THE CASCADES AND SOUTHEAST CWA
TUESDAY INTO TUESDAY EVENING, EXPANDING OVER MOST OF THE AREA
TUESDAY OVERNIGHT AND ESPECIALLY INTO WEDNESDAY WHEN POPS PEAK
AROUND 60-80% OVER THE EAST THIRD OF WA AND ID AND 30-50% OVER
THE CENTRAL WA, UP TO NEAR 60% AT THE CASCADE CREST. THEN
THE HIGHER CHANCES START TO RETREAT INTO THE MOUNTAINS THURSDAY
AND ESPECIALLY INTO FRIDAY. THIS WILL BE MAINLY RAIN AND HIGH
ELEVATION SNOW, WITH SNOW LEVELS AROUND 7.5-8.5KFT TUESDAY
DROPPING TO AROUND 4.5-5KFT BY THURSDAY. ADDITIONALLY, THERE
WILL BE SOME EMBEDDED T-STORM RISK TUESDAY AFTERNOON AND AGAIN
WEDNESDAY AFTERNOON ACROSS THE EASTERN THIRD OF WA AND ID. THIS
WILL BE FINE-TUNED AS WE GET CLOSER AS THE TIMING OF THE BEST
LIFT AND INSTABILITY MAY NOT SYNC UP. YET WITH THE MILDER AIR
AHEAD OF THE SYSTEM AND A FRONT MOVING IN, AT LEAST A SMALL RISK
FOR SOME T-STORMS SEEMS REASONABLE.
RAIN AMOUNTS BETWEEN 0.50" TO 0.75" ARE IN THE FORECAST FOR
TUESDAY NIGHT INTO THURSDAY, LOCALLY NEAR 1" TO 1.3" NEAR THE
HIGHER PALOUSE INTO THE PANHANDLE MOUNTAINS ZONES. CENTRAL WA
INTO THE CASCADES HAS AROUND 0.15" TO 0.40", LOCALLY LOWER IN
THE SHELTERED CASCADE VALLEYS. OVERALL THIS MEANS A GOOD CHANCE
OF WETTING RAIN, AT AROUND 60-90% DOWN TO AROUND 40-50% OVER THE
DEEPER BASIN. WITH MILDER TEMPERATURES AHEAD OF THIS AND THEN
THEN THE RAIN, THIS COMES WITH SOME RISES IN AREA RIVERS, THOUGH
MOST MAINSTEM RIVER REMAIN BELOW ACTION STAGE. STEHEKIN IS AN
EXCEPTION WHICH MAY SEE RISES EARLY IN THE NEW WORK WEEK. SO
THAT WILL BE MONITORED. STREAMS AND CREEKS AND POOR DRAINAGE
AREAS AND FIELDS WILL BE MONITORED FOR FLOODING AS WELL.
TEMPERATURES REMAIN MILD TUESDAY WITH HIGHS IN THE 70S AND SOME
LOW 80S POSSIBLE IN THE DEEPER BASIN. THEREAFTER HIGHS DROP
ABOUT 15 DEGREES HEADING INTO WEDNESDAY AND BEYOND WITH READINGS
IN THE UPPER 50S AND 60S. LOWS WILL BE IN THE 40S TO LOW 50S
WEDNESDAY MORNING, THEN UPPER 30S AND 40S THURSDAY AND FRIDAY
MORNING. WITH THE DROPPING TEMPERATURES LOOK FOR SOME BREEZY
CONDITIONS, ESPECIALLY WEDNESDAY AND THURSDAY WITH GUSTS IN THE
15 TO 25 MPH RANGE, HIGHEST NEAR THE CASCADES TO UPPER COLUMBIA
BASIN. /SOLVEIG
AVIATION
06Z TAFS: HIGH CONFIDENCE FOR VFR CONDITIONS FOR ALL TAF SITES
AS HIGH PRESSURE DEVELOPS ALOFT. THERE WILL BE MID AND HIGH
LEVEL CLOUDS INCREASING OVER CENTRAL AND EASTERN WA IN RESPONSE
TO A SYSTEM WELL OFF THE COAST. OTHERWISE, MAINLY FAIR CUMULUS
CLOUDS IN THE IDAHO PANHANDLE BETWEEN 19-02Z. MOST SITES WILL
EXPERIENCE LIGHT WINDS OF LESS THAN 10KTS. PUW IS THE EXCEPTION
WITH A PERIOD OF EASTERLY WINDS AROUND 14KTS 10-19Z.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE PERIOD AND
INCREASED WINDS FOR KPUW.
-----------------------
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 32 62 38 70 44 75 / 0 0 0 0 0 0
COEUR D'ALENE 31 60 38 70 44 75 / 0 0 0 0 0 0
PULLMAN 32 60 39 68 45 74 / 0 0 0 0 0 0
LEWISTON 35 66 40 73 47 77 / 0 0 0 0 0 0
COLVILLE 29 62 34 72 41 78 / 0 0 0 0 0 0
SANDPOINT 31 58 36 67 43 73 / 0 0 0 0 0 0
KELLOGG 30 59 37 69 46 75 / 0 0 0 0 0 0
MOSES LAKE 35 68 40 76 46 81 / 0 0 0 0 0 0
WENATCHEE 40 64 44 72 51 77 / 0 0 0 0 0 0
OMAK 37 64 41 73 47 79 / 0 0 0 0 0 0
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
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