533
FXUS66 KPDT 290531
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1031 PM PDT THU MAY 28 2026
KEY MESSAGES
- SCATTERED THUNDERSTORMS CAPABLE OF STRONG/DAMAGING GUSTS AND
ISOLATED LARGE HAIL WILL IMPACT THE FORECAST AREA THIS
AFTERNOON AND EVENING
- HEAVY DOWNPOURS EMBEDDED WITHIN THUNDERSTORMS WILL BRING AN
EXCESSIVE RAINFALL THREAT TO THE CASCADE EAST SLOPES TODAY
- BREEZY TO LOCALLY GUSTY WINDS THROUGH THE CASCADE GAPS AND
LOWER COLUMBIA BASIN FRIDAY
UPDATE
A WIND ADVISORY IS ISSUED FOR THE KITTITAS VALLEY FRIDAY MORNING
THROUGH FRIDAY EVENING. EXPECTED SUSTAINED WINDS OF 25 TO 35
MPH, WITH UP TO 50 MPH GUSTS DEVELOPING.
DISCUSSION
SEVERE CONVECTION AN BRIEF HEAVY RAINS ARE GOING TO BE THE
PRIMARY WEATHER HAZARDS TODAY FOLLOWING AFTERNOON LOW END HEAT
RISK (CATEGORY 2) OVER THE WASHINGTON COLUMBIA BASIN AND YAKIMA
VALLEY AND EASTERN COLUMBIA RIVER GORGE. HIGHS THIS AFTERNOON
WILL PEAK IN THE LOW 90S IN THE AND LOWER COLUMBIA BASIN, AND
INTO THE MID 80S ACROSS CENTRAL OREGON AND THE BLUE MT
FOOTHILLS. THE CATEGORY 2 HEAT RISK (MODERATE) AFFECTS THOSE WHO
ARE SENSITIVE TO HEAT ESPECIALLY THOSE WITHOUT COOLING/HYDRATION
AND SOME HEALTH SYSTEMS AND INDUSTRIES.
SHALLOW CONVECTION HAS ALREADY DEVELOPED ACROSS THE NORTHERN
PERIPHERY OF THE UPPER LOW, NAMELY ACROSS CROOKS INTO SOUTHERN
DESCHUTES COUNTIES WITH OCCASIONAL DRY LIGHTNING NOTED ON ETLN 5
AND 1 MINUTE. INTERESTINGLY HRRR MODELED UPDRAFT HELICITIES ARE
NOT VERY ROBUST AS THE MODELED CONVECTIVE ELEMENTS MOVE INTO
THE PDT CWA AFTER MID AFTERNOON WHICH COULD LIMIT THE FREQUENCY
OF SEVERE EVENTS (HAIL/DAMAGING WIND REPORTS).
THE GENERAL TREND IS FOR THE SOUTHWEST TO NORTHEAST BROKEN
LINEAR CONVECTION TO SPREAD INTO SOUTHERN OREGON AND THE BLUE
MOUNTAINS FROM MID AFTERNOON THOUGH ABOUT EARLY EVENING BEFORE
CONTINUING NORTH INTO A LOWER CAPE ENVIRONMENT ACROSS THE
WASHINGTON VALLEYS AND UPPER COLUMBIA BASIN LATE THIS EVENING.
THE HREF CAMS SOLUTIONS WITH THE MOST SCENARIOS OF LONGER LIVED
AND STRONGER ROTATING STORMS FAVORS THE OCHOCO JOHN DAY
HIGHLANDS AND DESCHUTES COUNTY AND THE OREGON COUNTIES IN
GENERAL. PRECIPITATION POTENTIAL FROM THE NBM MEAN RANGES FOR UP
TO ONE TENTH OF AN INCH OVER THE LOWER COLUMBIA BASIN AND
EXPANSION TO ONE QUARTER INCH ACROSS THE REST OF THE FORECAST
AREAS, WITH THE EXCEPTION OF MUCH HIGHER RAINFALL AMOUNTS IN
THREE QUARTER OF AN INCH TO ONE INCH RANGE OVER CENTRAL OREGON
AND THE OREGON EASTERN SLOPES. LOCAL FLASH FLOODING IS POSSIBLE
IN THESE AREAS ESPECIALLY OVER ANY PREEXISTING BURN SCARS OVER
THE LAST COULD OF YEARS WITH THESE RAINS UPWARDS OF AN INCH
OVERNIGHT.
BEYOND THE CONVECTIVE SETUP FOR LOOK FOR STRONGER WIND SPEEDS
AND GUSTS ESPECIALLY THOUGH THE KITTITAS VALLEY ON FRIDAY BASED
ON GAP WINDS/GRADIENT FORGINGS.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
THUNDERSTORM ACTIVITY HAS SINCE MOVE AWAY FROM ALL TAF SITES.
WILL PROBABLY SEE A THUNDER-SHOWER AT YKM/DLS/BDN/RDM THROUGH
THE EARLY MORNING HOURS TONIGHT BUT NOT ANYTHING IMPACTFUL. MVFR
CONDITIONS ARE HAPPENING AT BDM/RDM BUT NOT EXPECT THEM TO LAST
LONG WHEN A POCKET OF DRY AIR WILL MOVE INTO THE AREA, RAISING
CEILING LEVELS TO VFR STATUS. WILL SEE SOME BREEZY WINDS OF
25-35 KNOTS PERSIST THROUGH SOME OF THE TAF SITES, BUT NOT
EXPECTING WIND ADVISORY CRITERIA AT ANY OF THEM.
PRELIMINARY POINT TEMPS/POPS
PDT 51 68 42 67 / 60 0 10 0
ALW 57 71 47 68 / 60 0 10 0
PSC 54 74 46 73 / 70 10 10 0
YKM 57 72 43 73 / 80 50 0 0
HRI 54 69 44 70 / 70 10 10 0
ELN 54 65 40 65 / 80 40 0 0
RDM 42 59 32 63 / 100 80 0 0
LGD 48 72 41 64 / 70 40 10 0
GCD 42 67 37 66 / 50 50 20 0
DLS 55 67 45 70 / 90 50 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...WIND ADVISORY FROM 11 AM TO 11 PM PDT FRIDAY FOR WAZ026.
OR...NONE.
UPDATE...95
DISCUSSION...71
AVIATION...95
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