661
FXUS66 KPDT 142254
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
354 PM PDT TUE JUL 14 2026
KEY MESSAGES
- CHANCES OF AN ISOLATED TO SCATTERED THUNDERSTORM ACROSS
CENTRAL OR AND THE EASTERN MOUNTAINS CONTINUE THROUGH THIS
AFTERNOON. CHANCES RESUME WEDNESDAY AND POSSIBLY THURSDAY.
- MODELS STILL ADVERTISE UNCERTAINTY WITH THE EVOLUTION OF THE
CUT-OFF LOW PRESSURE SYSTEM OFFSHORE. SOLUTIONS TREND TOWARD
THE LOW PRESSURE SYSTEM MOVING INTO BRITISH COLOMBIA.
- WARM/DRY CONDITIONS WITH HIGH TEMPERATURES IN THE LOW TO
UPPER 90S PERSIST THROUGH THE WEEK.
DISCUSSION
RADAR CURRENTLY SHOWS LIGHT RETURNS ACROSS THE COLOMBIA BASIN
THROUGH THE EASTERN MOUNTAINS WITH ISOLATED THUNDERSTORMS
DEVELOPING NEAR GRANT AND SOUTHERN UNION COUNTY'S. A CUT-OFF LOW
PRESSURE SYSTEM JUST OFF SHORE IS ALLOWING A LIFTING MECHANISM
TO INITIATE SHOWERS AND THUNDERSTORMS THROUGH THE MIDDLE OF THE
WEEK. A RIDGE EXTENDING OVER THE GREAT PLAINS AND INTO THE
IDAHO/EASTERN OREGON REGION IS SIMULTANEOUSLY ALLOWING WARM
TEMPERATURES IN THE LOW TO UPPER 90S TO PERSIST (50-70%
CONFIDENCE) AND TRANSPORTING MID-LEVEL MONSOONAL MOISTURE. WITH
THE LIFT OF THE LOW PRESSURE SYSTEM, MOISTURE TRANSPORTATION,
AND WARMER TEMPERATURES, CHANCES OF ISOLATED TO SCATTERED
THUNDERSTORMS PERSIST THROUGH THURSDAY. THE RRFS MODEL HAS BEEN
HANDLING THE CONVECTION THE BEST THROUGH THIS AFTERNOON. THAT
SAME MODEL TAKES CONVECTION UP INTO THE EASTERN
MOUNTAINS/NORTHERN FOOTHILLS OF THE BLUES LATER THIS AFTERNOON.
MANY SHORT TERM MODELS ARE IN AGREEMENT THAT WE'LL SEE NOCTURNAL
LIGHT TO MODERATE RAIN SHOWER ACTIVITY MOVE-UP CENTRAL OR
THROUGH THE KITTITAS VALLEY BY THE EARLY MORNING HOURS (40-50%
CONFIDENCE) WITH OVERNIGHT THUNDERSTORMS A POSSIBILITY.
MOVING FORWARD, THE SYNOPTIC SET-UP IS UNCLEAR WITH THE CLUSTER
MEMBERS STRUGGLING WHETHER IT WANTS TO TAKE THE LOW PRESSURE
SYSTEM ON-SHORE OR KEEP IT OFF THE COAST. CLUSTERS REMAIN SPLIT
OVER THE NEXT FEW DAYS, WITH A SOMEWHAT EVEN SPLITTING FOR
DIFFERENT SCENARIOS WHETHER IT WANTS TO KEEP THE LOW OFFSHORE OR
ONSHORE. LOOKING AT CLUSTERS, 60% OF MEMBERS WANT TO PUSH THE
LOW JUST OFF-SHORE BY LATE WEDNESDAY AFTERNOON, WHILE THE
REMAINING 40% KEEP IT WELL OFFSHORE AND KEEP THE WEATHER DRIER.
THE SPLIT CONTINUES LATE AFTERNOON ON THURSDAY WITH 47% OF
MEMBERS BRINGING THE LOW INTO WASHINGTON AND OREGON, WITH THE
REMAINING 53% KEEP IT OFF THE PACNW COAST. BOTTOM LINE IS THAT
CONFIDENCE IS NOT GREAT TO EITHER SOLUTION AT THIS TIME, BUT
THERE'S BEEN A SLIGHT TREND TOWARDS THE SOLUTION THAT FAVORS THE
LOW PRESSURE SYSTEM MOVING ONSHORE AND THEN EVENTUALLY INTO
BRITISH COLOMBIA.
THE EVENTUAL LOCATION OF THE LOW-PRESSURE SYSTEM WILL EFFECT OUR
HEATRISK'S OVER THE NEXT SEVERAL DAYS WITH A SOLUTION OF THE
LOW STAYING OFFSHORE RESULTING IN WARMER CONDITIONS OR COOLER
CONDITIONS IF MOVED ONSHORE. CURRENT HEATRISK PROBABILISTICS
ADVERTISE WIDESPREAD 40-80% CHANCES OF A MODERATE OR HIGHER
RISK, WITH WEDNESDAY LOOKING TO BE THE PEAK SHOWING >90%
VIRTUALLY COVERING THE ENTIRE LOWER ELEVATIONS OF SOUTH-CENTRAL
WASHINGTON AND PARTS OF NORTHEASTERN OREGON. CHANCES FOR A
MAJOR HEAT RISK IS AROUND 20-40% TUESDAY TO THURSDAY. HEAT
ADVISORY'S ARE POSSIBLE ACROSS PARTS OF KITTITAS/ELLENSBURG AREA
IF SOLUTIONS OF THE LOW PRESSURE STAYING OFF SHORE VERIFY, BUT
WITH LOW CONFIDENCE IN DETERMINING THE POSITION OF THE LOW, A
CALL TO INITIATE A HIGHLIGHT HASN'T BEEN MADE YET.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. THERE IS A VERY
LOW CHANCE (5-10%) OF ISOLATED THUNDERSTORMS FOR BDN/RDM THIS
AFTERNOON AND EARLY EVENING, BUT CONFIDENCE WAS TOO LOW TO
INCLUDE MENTION IN THE 00Z TAFS. 12Z HREF AND REFS GUIDANCE
BOTH ADVERTISE ANOTHER ROUND OF HIGH-BASED SHOWERS OVERNIGHT
INTO WEDNESDAY MORNING, BUT CONFIDENCE IN MEASURABLE
PRECIPITATION AT ANY TAF SITE WAS TOO LOW (<30%) TO MENTION. BY
WEDNESDAY AFTERNOON, ISOLATED THUNDERSTORMS ARE ANTICIPATED TO
DEVELOP ACROSS THE HIGH TERRAIN OF CENTRAL OREGON, SPREADING
NORTH IN THE VICINITY OF BDN/RDM BY MID/LATE AFTERNOON; FOR THIS
CONVECTIVE POTENTIAL, INCLUDED A PROB30 GROUP.
WINDS WILL BE DIURNALLY AND TERRAIN-DRIVEN, MOSTLY LIGHT WITH
A COUPLE EXCEPTIONS. PERIODS OF BREEZY WINDS ARE ANTICIPATED
DURING THE AFTERNOON/EVENING HOURS FOR DLS/BDN/RDM, AND ANY
CONVECTION THAT DEVELOPS WILL BE CAPABLE OF PRODUCING ERRATIC,
GUSTY OUTFLOW WINDS.
PRELIMINARY POINT TEMPS/POPS
PDT 62 96 61 92 / 0 0 30 10
ALW 65 99 66 96 / 0 0 20 10
PSC 63 100 64 97 / 0 0 30 20
YKM 65 98 66 95 / 0 0 50 40
HRI 65 99 65 94 / 0 0 30 20
ELN 62 96 63 91 / 0 10 50 50
RDM 56 91 54 86 / 10 40 30 10
LGD 59 95 60 97 / 0 0 20 20
GCD 58 93 58 96 / 20 20 30 10
DLS 66 98 65 85 / 0 10 60 30
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...95
AVIATION...86
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