086
FXUS66 KOTX 151752
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1052 AM PDT FRI AUG 15 2025
KEY MESSAGES
- COOLING TREND CONTINUES THROUGH WEEKEND.
- RAIN DEVELOPING IN THE CASCADES FRIDAY, SPREADING EAST FRIDAY
NIGHT INTO SATURDAY. HIGHEST RAIN AMOUNTS IN THE CASCADES,
NORTHERN MOUNTAINS.
- ISOLATED THUNDERSTORMS POSSIBLE SATURDAY.
SYNOPSIS
A COOLING TREND IS EXPECTED THROUGH THE WEEKEND UNDER THE
INFLUENCE OF A LOW PRESSURE SYSTEM IN THE GULF OF ALASKA. WITH
A DECENT SURGE OF MOISTURE, THE SYSTEM WILL BRING RAIN STARTING
IN THE CASCADES FRIDAY BEFORE SPREADING EAST INTO EASTERN
WASHINGTON AND NORTH IDAHO ON SATURDAY. ISOLATED THUNDERSTORMS
ARE POSSIBLE SATURDAY AFTERNOON. BY TUESDAY, A BROAD RIDGE WILL
BRING DRY CONDITIONS AND NEAR NORMAL TEMPERATURES BACK TO THE
AREA.
DISCUSSION
FRIDAY THROUGH MONDAY: A CLOSED LOW SPINNING IN THE GULF OF ALASKA
HAS BEGUN DIRECTING A STREAM OF MOISTURE AT THE WA COAST, SENDING A
BAND OF RAINFALL ACROSS THE OLYMPIC PENINSULA AND OVER THE PUGET
SOUND TONIGHT. THOSE OF US EAST OF THE CASCADES WILL HAVE TO WAIT
ANOTHER DAY FOR OUR RAIN. THIS IS SOMEWHAT OF A UNIQUE EVENT FOR MID-
AUGUST WITH PRECIPITABLE WATER VALUES SOARING TO OVER AN INCH, OR
NEAR 200 PERCENT OF NORMAL. A LIMITED AMOUNT OF MOISTURE WILL MAKE
IT OVER THE CASCADES TONIGHT INTO FRIDAY MORNING BRINGING SLIGHT
CHANCES FOR SHOWERS TO THE NORTHERN MOUNTAINS, BUT THIS INITIAL
ROUND OF SHOWERS WILL BE ISOLATED IN NATURE. ASIDE FROM THESE
ISOLATED MORNING SHOWERS, COOL AND DRY ZONAL FLOW IS EXPECTED
THROUGH THE DAY ON FRIDAY, THEN A REINFORCING SHOT OF MOISTURE WILL
BRING MORE WIDESPREAD SHOWERS TO EASTERN WA AND NORTH ID FRIDAY
NIGHT THROUGH SATURDAY. MOST OF THE REGION HAS AT LEAST A 45% CHANCE
OF RECEIVING AT LEAST 0.1 INCHES OF RAIN BETWEEN FRIDAY NIGHT AND
SUNDAY MORNING. ACCUMULATIONS EXPECTED FOR MOST LOWLAND LOCATIONS
RANGE FROM 0.05 TO 0.25 INCHES OF RAIN. THE HIGHEST RAINFALL AMOUNTS
ARE EXPECTED OVER THE CASCADE CREST AND IN NORTHEAST WA AND NORTH ID
WHERE ACCUMULATIONS WILL RANGE FROM 0.4 TO 0.75 INCHES. MODEST
INSTABILITY WILL BRING ISOLATED THUNDERSTORM CHANCES SATURDAY
AFTERNOON, THOUGH WITH ABUNDANT CLOUD COVER AND COOL TEMPERATURES,
STORMS ARE NOT EXPECTED TO BE STRONG. BRIEF HEAVY RAIN AND ISOLATED
LIGHTNING STRIKES WILL BE THE BIGGEST THREATS WITH ANY STORMS THAT
DEVELOP. SHOWERS WILL TAPER OFF SATURDAY NIGHT INTO SUNDAY AS THE
LOW IN THE GULF OF ALASKA WEAKENS AND A RIDGE OF HIGH PRESSURE OVER
THE CENTRAL US RETROGRADES OVER THE WEST COAST.
TUESDAY ONWARD: CONDITIONS WILL TREND WARMER AND DRIER WITH THE
RIDGE OF HIGH PRESSURE FORECASTED TO STAY PUT OVER THE REGION.
HIGHS WILL GRADUALLY CLIMB BACK INTO 80S AND LOW 90S, AND
OVERNIGHT LOWS WILL BE IN UPPER 40S AND 50S. /FEWKES
AVIATION
12Z TAFS: A WEATHER SYSTEM WILL SEND A SLUG OF MOISTURE INTO CENTRAL
AND NE WASHINGTON THIS MORNING BRINGING RAIN TO KMWH/KOMK AND POSSIBLE
KCQV/KGEG. THE BACK EDGE OF THE RAIN WILL CLEAR KEAT NEAR 12Z. AFTER
THIS BRIEF BAND OF RAIN, A BREAK WILL OCCUR UNTIL THE COLD FRONT
PASSAGE. THIS FRONT WILL REACH KEAT NEAR 06Z SAT, KMWH NEAR 10Z SAT,
AND AFTER 12Z FOR KGEG/KSFF/KCOE/KPUW/KLWS. CIGS WILL LOWER AS STEADY
RAIN DEVELOPS, ALTHOUGH CIGS ARE EXPECTED TO REMAIN VFR AT THE TAF
SITES THROUGH 12Z SAT. TAKING A PEAK AFTER THAT THE HREF HAS A 80%
CHANCE KGEG WILL DROP TO MVFR CIGS BETWEEN 15Z-18Z SAT AS RAIN DEVELOPS
AND THE BOUNDARY LAYER SATURATES. JW
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
HIGH CONFIDENCE FOR CIGS TO REMAIN VFR AT THE TAF SITES THROUGH 12Z SAT.
THERE IS A 10-20% CHANCE CONDITIONS DROP TO MVFR AT KEAT/KMWH 9-12Z SAT
FROM REDUCED VISIBILITY IN RAIN.
-----------------------
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:/WEATHER.GOV/OTX/AVNDASHBOARD
AVIATION
18Z TAFS: VFR CONDTIONS ARE EXPECTED. INCREASING HIGH TO MID
LEVEL CLOUDS EXPECTED AS AN INCOMING COLD FRONT WILL MOVE
THROUGH OVERNIGHT. THIS FRONT WILL REACH KEAT NEAR 06Z SAT,
KMWH NEAR 10Z SAT, AND AFTER 12Z FOR KGEG/KSFF/KCOE/KPUW/KLWS.
CIGS WILL LOWER AS STEADY RAIN DEVELOPS. TAKING A PEAK AFTER
THAT THE HREF HAS A 80% CHANCE KGEG WILL DROP TO MVFR CIGS
BETWEEN 15Z-18Z SAT AS RAIN DEVELOPS AND THE BOUNDARY LAYER
SATURATES. JDC
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
HIGH CONFIDENCE FOR CIGS TO REMAIN VFR AT THE TAF SITES THROUGH
18Z SAT. THERE IS A 10-20% CHANCE CONDITIONS DROP TO MVFR AT
KEAT/KMWH 9-12Z SAT FROM REDUCED VISIBILITY IN RAIN.
PRELIMINARY POINT TEMPS/POPS
SPOKANE 81 61 76 56 81 54 / 20 30 70 10 0 10
COEUR D'ALENE 81 62 75 56 81 56 / 10 20 70 10 0 10
PULLMAN 80 56 73 51 78 52 / 10 20 50 10 10 20
LEWISTON 90 67 83 63 87 64 / 10 10 40 20 10 20
COLVILLE 77 50 76 46 81 44 / 30 70 80 10 0 0
SANDPOINT 77 56 73 52 80 49 / 20 30 80 10 0 10
KELLOGG 80 62 72 58 78 59 / 10 10 60 10 10 20
MOSES LAKE 84 62 83 53 82 54 / 30 50 50 0 0 0
WENATCHEE 81 66 83 59 82 61 / 40 70 50 0 0 0
OMAK 80 62 84 55 84 56 / 30 80 30 0 0 0
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
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