888
FXUS66 KPDT 300534
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1034 PM PDT SUN JUN 29 2025
.UPDATED AVIATION DISCUSSION.
AVIATION...06Z TAFS
VFR CONDITIONS CURRENTLY ACROSS ALL SITES,
WHICH WILL STAY THE COURSE THROUGH THE PERIOD. CLEAR SKIES AND LIGHT
WINDS BELOW 10 KTS ARE EXPECTED. KRDM/KBDN ARE THE ONLY EXCEPTIONS
AS SCT CLOUDS AT 25KFT WILL MOVE IN FROM THE SOUTH AND INCREASING
NORTH WINDS OF 10-15 KTS ARE ANTICIPATED LATE MONDAY AFTERNOON.
THERE IS ALSO A SLIGHT CHANCE (15%) OF A PASSING SHOWER OR ISOLATED
THUNDERSTORM AFTER 00Z FOR KRDM/KBDN, BUT CONFIDENCE IS CURRENTLY
TOO LOW TO INCLUDE IN TAF. 75
PREV DISCUSSION... /ISSUED 146 PM PDT SUN JUN 29 2025/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT...QUIET WEATHER IS
FORECAST FOR THE REMAINDER OF TODAY, TONIGHT, AND MUCH OF MONDAY
AS AN UPPER-LEVEL RIDGE OF HIGH PRESSURE BUILDS INTO THE PACIFIC
NORTHWEST. THE RIDGE WILL FACILITATE LIGHT OFFSHORE FLOW INTO
MONDAY, AND MORE NOTABLY, WARMING TEMPERATURES.
ENSEMBLE NWP IS VERY CONFIDENT (95% OR GREATER) THAT THE
AFOREMENTIONED UPPER-LEVEL RIDGE WILL AMPLIFY THROUGH MONDAY AND
REMAIN IN PLACE THROUGH TUESDAY, LEADING TO HOT CONDITIONS.
MEANWHILE, AN UPPER-LEVEL CLOSED LOW WILL CONTINUE TO DEVELOP OFF
THE CENTRAL CALIFORNIA COAST, SETTING THE STAGE FOR CONVECTION IN
SOUTHERN/EASTERN OREGON MONDAY AND TUESDAY.
CAMS SUGGEST THE BULK OF THE CONVECTIVE ACTIVITY MONDAY WILL BE
ACROSS SOUTH-CENTRAL OREGON WITH LIMITED EXTENSION NORTHWARD INTO
CENTRAL OREGON, PERHAPS DUE TO WEAK FORCING ALOFT. THAT SAID,
HAVE MAINTAINED A SLIGHT CHANCE (15%) OF THUNDERSTORMS IN THE
FORECAST FOR THE EAST SLOPES OF THE OREGON CASCADES IN DESCHUTES
COUNTY AND ALSO FOR AREAS EAST INTO THE OCHOCOS-JOHN DAY
HIGHLANDS. CONFIDENCE IS LOW (<50%) THAT THUNDER WILL ACCOMPANY
ISOLATED TO SCATTERED SHOWERS IN CENTRAL AND EASTERN OREGON
MONDAY NIGHT, SO HAVE OMITTED MENTION IN THE FORECAST. SHOULD
MENTION THAT, DUE TO AMPLE FORECAST DCAPE OF 1000-1500 J/KG PER
HREF AND REFS SOUNDINGS, CONVECTIVE OUTFLOW HAS THE POTENTIAL TO
GENERATE GUSTS IN EXCESS OF 50 MPH IN CENTRAL OREGON MONDAY
AFTERNOON, AND THE SPC HAS A MARGINAL (LEVEL 1 OF 5) RISK OF
SEVERE THUNDERSTORMS PLACED JUST SOUTH OF DESCHUTES COUNTY.
CONVECTIVE POTENTIAL LOOKS BETTER TUESDAY ACROSS THE BLUE
MOUNTAINS REGION WHERE A SLIGHT CHANCE (15-24%) TO CHANCE
(25-30%) OF SHOWERS AND THUNDERSTORMS HAS BEEN INCLUDED DUE TO THE
COMBINATION OF SUFFICIENT MID-LEVEL MOISTURE, INSTABILITY, AND
MODEST UPPER-LEVEL FORCING.
ANTICIPATED WARMING UNDER THE UPPER-LEVEL RIDGE HAS PROMPTED THE
ISSUANCE OF HEAT ADVISORIES FOR MOST OF OUR LOWER-ELEVATION AREAS
ACROSS NORTHERN OREGON AND SOUTH-CENTRAL WASHINGTON FOR MONDAY
THROUGH TUESDAY. WIDESPREAD MODERATE (LEVEL 2 OF 4) TO MAJOR
(LEVEL 3 OF 4) HEATRISK IS ON TAP DUE TO FORECAST HIGH
TEMPERATURES OF 91-103 DEGREES AND OVERNIGHT LOW TEMPERATURES OF
61-73 DEGREES. WILL NOTE THERE IS SOME UNCERTAINTY IN HIGH AND LOW
TEMPERATURES TUESDAY AND WEDNESDAY DUE TO POTENTIAL CLOUD COVER
-- CONVECTIVE DEBRIS OR OTHERWISE. PLUNKETT/86
LONG TERM...WEDNESDAY THROUGH SATURDAY...WEDNESDAY THROUGH
FRIDAY, ANALYSIS OF ENSEMBLE CLUSTERS INDICATES THERE IS MORE
UNCERTAINTY (TIMING AND AMPLITUDE OF 500-HPA HEIGHTS) IN PATTERN
DETAILS, BUT GUIDANCE IS STRONGLY SUGGESTING ONE OR MORE
SHORTWAVES EMBEDDED WITHIN BROADLY SOUTHWESTERLY FLOW ALOFT. THIS
PATTERN FAVORS SHOWERS AND THUNDERSTORMS FOR THE BLUE MOUNTAINS
REGION, SO HAVE ADDED A SLIGHT CHANCE (15%) OF THUNDER EACH
AFTERNOON.
OTHERWISE, BREEZY TO WINDY WESTERLY WINDS ARE FAVORED THROUGH THE
CASCADE GAPS WEDNESDAY THROUGH THURSDAY. CONFIDENCE IN SURFACE
MOISTURE (DEW POINT AND RELATIVE HUMIDITY) IS STILL LOW (<30%) DUE
TO AFOREMENTIONED UNCERTAINTY IN PATTERN DETAILS SO WILL HOLD OFF
ON MENTIONING POTENTIAL FOR ANY FIRE WEATHER HIGHLIGHTS.
PLUNKETT/86
PRELIMINARY POINT TEMPS/POPS
PDT 57 98 64 101 / 0 0 0 0
ALW 62 97 68 100 / 0 0 0 0
PSC 59 99 64 103 / 0 0 0 0
YKM 62 97 66 100 / 0 0 0 0
HRI 59 99 64 103 / 0 0 0 0
ELN 58 96 64 98 / 0 0 0 0
RDM 52 95 60 95 / 0 0 20 0
LGD 56 95 60 97 / 0 0 0 0
GCD 56 97 61 97 / 0 0 10 10
DLS 64 101 68 97 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
OR...HEAT ADVISORY FROM 9 AM MONDAY TO 9 PM PDT TUESDAY FOR ORZ041-
044-507-508-510.
WA...HEAT ADVISORY FROM 9 AM MONDAY TO 9 PM PDT TUESDAY FOR WAZ024-
026>029-521.
SHORT TERM...86
LONG TERM....86
AVIATION...75
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