994
FXUS66 KPDT 101007
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
307 AM PDT FRI JUL 10 2026
KEY MESSAGES
- WARMER DAY TODAY, SLIGHT COOLING THROUGH THE WEEKEND.
*HEAT ADVISORY ACTIVE*
- DRY AND BREEZY THROUGH SATURDAY, LOWER WINDS NEXT WEEK.
- ELEVATED FIRE WEATHER CONCERNS THROUGH SATURDAY.
DISCUSSION
CURRENT RADAR AND INFRARED SATELLITE IMAGERY SHOWS DRY
CONDITIONS UNDER CLEAR SKIES. THIS IS IN RESPONSE TO A BUILDING
UPPER LEVEL RIDGE TO OUR SOUTHEAST, KEEPING SKIES CLEAR AND
CONDITIONS DRY. ENHANCING TODAY'S WARMING WILL BE A DROPPING
UPPER LEVEL LOW PRESSURE ALONG THE BRITISH COLUMBIA COAST, THAT
WILL SHIFT FLOW ALOFT FROM THE WEST TO THE SOUTHWEST DURING THE
DAY.THESE FEATURES WILL ALLOW HIGH TEMPERATURES TO REACH INTO
THE LOW TO MID-90S ACROSS THE LOWER COLUMBIA BASIN, BLUE
MOUNTAIN FOOTHILLS, CENTRAL OREGON, JOHN DAY BASIN, AND YAKIMA
VALLEY. EXCESSIVE HEAT IS EXPECTED THROUGH THE HELLS CANYON AREA
AS HIGH PRESSURE DOMINATES FROM THE SOUTHEAST AND ADVECTS A
MORE DRY, CONTINENTAL AIRMASS ACROSS FAR EASTERN OREGON. DAILY
HIGH TEMPERATURES OF UP TO 105 WILL BE POSSIBLE WITH WIDESPREAD
MODERATE HEATRISK (2 OUT OF 4). THESE CONDITIONS HAVE WARRANTED
THE ISSUANCE OF A HEAT ADVISORY FOR THE HELLS CANYON AREA BELOW
3000 FEET FROM NOON TODAY THROUGH 7 PM SUNDAY. IF IN THIS AREA
OVER THE NEXT 72 HOURS, MAKE SURE TO STAY HYDRATED AND TAKE
PRECAUTIONS FROM THE HEAT. ISOLATED AREAS OF MODERATE HEATRISK
WILL BE PRESENT TODAY OVER THE BASIN AND FOOTHILLS, PRIMARILY
OVER THE YAKIMA, HANFORD, AND WALLA WALLA/MILTON FREEWATER
AREAS. THE UPPER LEVEL LOW OFFSHORE WILL CONTINUE TO DROP NEAR
VANCOUVER ISLAND SATURDAY BEFORE MOVING INLAND ON SUNDAY, WHICH
WILL BRING SLIGHTLY COOLER CONDITIONS ACROSS THE COLUMBIA BASIN
COUPLED WITH A SLIGHT UPTICK IN MOISTURE DUE TO THE ASSOCIATED
MARITIME AIRMASS.
THE APPROACHING UPPER LEVEL LOW OFFSHORE AND THE BUILDING UPPER
LEVEL RIDGE TO THE SOUTHEAST WILL TIGHTEN THE PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES. WEST-NORTHWEST WINDS OF 20-25 MPH
WITH GUSTS OF AROUND 35 MPH ARE EXPECTED ACROSS THE COLUMBIA
GORGE, SOUTHERN BLUE MOUNTAIN FOOTHILLS, AND THE KITTITAS
VALLEY, WITH 10-20 MPH WINDS AND GUSTS AROUND 25 MPH OVER THE
LOWER COLUMBIA BASIN, NORTHERN BLUE MOUNTAIN FOOTHILLS, AND THE
YAKIMA VALLEY. THESE WINDS ARE FORECAST TO PEAK BETWEEN 5 PM AND
8 PM TODAY, AS AN EMBEDDED SHORTWAVE MOVES THROUGH THE SOUTHWEST
FLOW ALOFT. IN THE WAKE OF ITS PASSING, UPPER LEVEL RIDGING
WILL INFILTRATE FROM THE SOUTHEAST TO CONFINE THESE BREEZY
CONDITIONS TO THE EASTERN GORGE, SIMCOE HIGHLANDS, AND THE
CASCADE GAPS/EAST SLOPES ON SATURDAY. THE UPPER LEVEL LOW RIDES
UP AND OVER THE RIDGE THROUGH CENTRAL CANADA ON MONDAY TO ALLOW
THE RIDGE TO STRENGTHEN ACROSS THE AREA AND LOWER WINDS SUNDAY
ONWARD. THE CONTINUED PRESENCE OF THE STRONG HIGH PRESSURE TO
OUR SOUTHEAST KEEPS CONDITIONS DRY UNTIL MONDAY/TUESDAY (15%
CHANCE) AS BOTH THE ECMWF AI ENSEMBLES AND GFS AI ENSEMBLES
ADVERTISE A PASSING SHORTWAVE MAY BRING INCREASED MOISTURE
ACROSS CENTRAL AND EASTERN OREGON - AS WELL AS ISOLATED
THUNDERSTORM CHANCES.
THE MORE WIDESPREAD WINDS AND LOW AFTERNOON HUMIDITIES DROPPING
INTO THE MID-TEENS ELEVATES FIRE WEATHER CONCERNS TODAY,
PRIMARILY BETWEEN 3 PM AND 7 PM ACROSS THE EASTERN GORGE AND THE
WARM SPRINGS AREAS. ELEVATED CONCERNS RETURN BRIEFLY SATURDAY
ACROSS THE YAKIMA VALLEY, AS WINDS DECREASE SUNDAY ONWARD TO
ALLEVIATE THESE CONCERNS INTO NEXT WEEK. 75
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
VFR CONDITIONS CURRENTLY ACROSS ALL SITES, WHICH WILL STAY THE
COURSE THROUGH THE PERIOD. BREEZY WINDS OF 10-20KTS AND GUSTS OF
20-30KTS WILL BE POSSIBLE FOR KDLS/KPDT/KRDM/KBDN THROUGH THE
DAY, WITH WINDS AROUND 10KTS ELSEWHERE. SKIES WILL STAY CLEAR,
WITH 25KFT FEW/SCATTERED CEILINGS LATE THIS EVENING. 75
FIRE WEATHER
MOST FIRE WEATHER CONCERN OCCURS TODAY BETWEEN 1500 AND 1900
ACROSS FIRE WEATHER ZONES WA691, OR691 AND OR703, BUT STAY
PRIMARILY ALONG THE WESTERN BORDERS OF THE WA/OR691 ZONES AND
EASTERN BORDER OF OR703. THE NBM HIGHLIGHTS HIGHEST CHANCES OF
CRITICAL HUMIDITIES AND WINDS BEING MET AROUND THE
ARLINGTON/IONE AREAS AT A 40-60% CHANCE AT 1700. EVEN MORE
ISOLATED CONCERNS ARE EXPECTED SATURDAY OVER THE WESTERN PORTION
OF WA691 BETWEEN 1700-1900 WITH A 40-50% CHANCE OF OCCURRENCE.
CONDITIONS WILL STAY DRY NEXT WEEK WITH MODERATE HUMIDITY
RECOVERIES BETWEEN 35-50% ACROSS THE COLUMBIA BASIN, BLUE
MOUNTAINS, AND CENTRAL OREGON, WITH AFTERNOON HUMIDITIES
BETWEEN 15-25% EACH DAY. THE LIMITING FACTOR WILL BE THE LACK OF
WIND DUE TO THE UPPER LEVEL HIGH TO OUR SOUTHEAST DOMINATING THE
WEATHER PATTERN. THE INCOMING SHORTWAVE MONDAY AND TUESDAY MAY
ALLOW FOR ISOLATED THUNDERSTORMS ACROSS OR693-700 AND OR705
ZONES, BUT CURRENTLY CONFIDENCE IS LOW (10-15%). 75
PRELIMINARY POINT TEMPS/POPS
PDT 90 56 87 58 / 0 0 0 0
ALW 93 62 90 62 / 0 0 0 0
PSC 95 60 92 61 / 0 0 0 0
YKM 94 57 90 58 / 0 0 0 0
HRI 93 60 89 61 / 0 0 0 0
ELN 87 54 83 53 / 0 0 0 0
RDM 89 47 88 53 / 0 0 0 0
LGD 94 55 94 58 / 0 0 0 0
GCD 96 54 96 57 / 0 0 0 0
DLS 88 60 85 59 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...HEAT ADVISORY FROM NOON TODAY TO 7 PM PDT SUNDAY FOR ORZ050.
DISCUSSION...75
AVIATION...75
FIRE WEATHER...75
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