229
FXUS66 KPDT 281912
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1212 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
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 /18Z TAFS THROUGH 18Z FRIDAY/
VFR CONDITIONS CURRENTLY ACROSS ALL SITES, WHICH WILL STAY THE
COURSE THROUGH THE PERIOD. HOWEVER, THERE MAY BE BRIEF PERIODS
OF MVFR FOR ALL TERMINALS DUE TO REDUCED VISIBILITIES
ASSOCIATED WITH DEVELOPING STRONG TO SEVERE THUNDERSTORMS THIS
AFTERNOON AND EVENING. THERE HAS ALREADY BEEN LIGHTNING REPORTED
NEAR KRDM/KBDN THIS MORNING, WITH THE POTENTIAL INTENSIFYING
THROUGH THE REMAINDER OF THE DAY. WINDY CONDITIONS WILL ALSO
COINCIDE WITH ANY DEVELOPING STORM CELLS AS OUTFLOW BOUNDARIES
COULD LEAD TO BRIEF WIND GUSTS OF AROUND 40 KTS. BRIEF HEAVY
DOWNPOURS AND LARGE HAIL (1+ INCH DIAMETER) WILL ALSO BE
POSSIBLE NEAR ANY DEVELOPING STORM CELLS. CEILINGS SHOULD STAY
AROUND 5KFT THROUGH THE DAY, SLOWLY IMPROVING TO 10KFT
OVERNIGHT. THE THUNDERSTORM THREAT DIMINISHES TONIGHT AS STORM
ACTIVITY SHIFTS TO OUR NORTH. 75
PRELIMINARY POINT TEMPS/POPS
PDT 51 69 42 67 / 60 10 10 0
ALW 57 72 47 68 / 50 10 10 0
PSC 54 75 45 73 / 70 20 10 0
YKM 57 73 43 72 / 90 40 10 0
HRI 54 70 44 70 / 60 20 10 0
ELN 54 66 40 64 / 80 40 0 0
RDM 42 59 32 62 / 90 60 10 0
LGD 48 72 42 64 / 60 50 10 0
GCD 42 69 37 65 / 60 60 20 0
DLS 55 67 45 69 / 90 40 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...71
AVIATION...75
HYDROLOGY...82
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