327  
FXUS66 KPDT 222014  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
114 PM PDT SAT JUL 22 2017  
   
SHORT TERM...TONIGHT THROUGH TUESDAY
 
SPLIT FLOW PATTERN WILL  
PERSIST THROUGH THE NEXT COUPLE OF DAYS WITH A NARROW RIDGE NUDGING  
NORTHWARD INTO OREGON WHILE THE NORTHERN BRANCH OF THE JET EXTENDS  
ACROSS WASHINGTON. MEANWHILE AN UPPER LOW WILL REMAIN OFF THE  
NORTHERN CA COAST. FOR TONIGHT EXPECT MOSTLY CLEAR SKIES AND WARM  
TEMPERATURES WITH LOWS MAINLY IN THE 60S AND 50S IN THE MOUNTAINS.  
ON SUNDAY IT WILL BE HOT WITH MOSTLY SUNNY SKIES. TEMPERATURES WILL  
BE 95-100 IN THE LOWER ELEVATIONS AND 80S IN THE MOUNTAINS. BY  
EVENING THERE WILL BE A SLIGHT CHANCE FOR THUNDERSTORMS OVER THE  
CENTRAL OREGON HIGHLANDS AS MOISTURE CREEPS NORTHWARD AHEAD OF THE  
UPPER LOW OFF THE CA COAST. THIS TREND WILL CONTINUE ON MONDAY WITH  
LOW CHANCES FOR SHOWERS/-TSRA OVER CENTRAL OR...PEAKING DURING THE  
LATE AFTERNOON AND EVENING. ON TUESDAY IT LOOKS LIKE THE MOISTURE  
COULD BE SHUNTED TO THE SOUTH A BIT WITH PRECIP CHANCES CONFINED TO  
MOSTLY DESCHUTES AND GRANT COUNTIES. IT WILL BE WARM BOTH MONDAY AND  
TUESDAY WITH HIGHS WELL INTO THE 90S LOWER ELEVATIONS AND  
80S/MOUNTAINS. 78  
   
LONG TERM
 
TUESDAY NIGHT THROUGH SATURDAY. UPPER LOW NEAR  
NORTHERN CALIFORNIA STARTS TO MOVE NORTHEAST TUESDAY NIGHT AND IS  
EXPECTED TO MOVE THROUGH OREGON AS AN OPEN WAVE ON WEDNESDAY WITH  
SEVERAL WEAK SYSTEMS MOVE ALONG THE CANADIAN BORDER. MOISTURE AND  
INSTABILITY IS SUPPRESSED MAINLY SOUTH OF THE FORECAST AREA TUESDAY  
NIGHT AND THEN THERE IS SOME LIMITED MOISTURE FROM CENTRAL OREGON  
THROUGH THE NORTHEAST OREGON MOUNTAINS ON WEDNESDAY BEFORE THE  
SYSTEM EXITS THE REGION BY THURSDAY. DRY AND HOT CONDITIONS ARE  
EXPECTED THROUGH THE REST OF THE WEEK WITH SOUTHWEST FLOW. THERE  
WILL BE SOME INSTABILITY DUE TO THE HEAT EACH DAY, BUT MOISTURE  
REMAINS LIMITED. HIGH TEMPERATURES WILL BE IN THE LOWER TO MID 90S,  
WITH 80S IN THE MOUNTAINS THROUGH THE PERIOD. 93  
 

 
   
AVIATION
 
00Z TAFS. VFR CONDITIONS WILL PREVAIL AT TAFS SITES  
THROUGH THE NEXT 24 HOURS. MOSTLY CLEAR SKIES AND LIGHT WINDS WILL  
CONTINUE TONIGHT AND SUNDAY MORNING. BY LATE DAY SUNDAY, THERE WILL  
BE SCT CLOUDS 070-100 ALONG THE SOUTHERN OREGON CASCADES AND MAY  
REACH NEAR KBDN AND KRDM. WINDS WILL BE INCREASING 15 TO 20 KTS  
THROUGH THE COLUMBIA RIVER GORGE AND AT KDLS BY LATE DAY AS WELL. 93  
 

 
   
FIRE WEATHER
 
EXPECT BREEZY CONDITIONS TO DEVELOP SUNDAY AFTERNOON  
ACROSS THE COLUMBIA GORGE/BASIN. RH VALUES WILL REMAIN TOO HIGH IN  
THE GORGE, WITH WINDS TOO LOW IN THE BASIN FOR A RED FLAG WARNING.  
WILL HIGHLIGHT THE THREAT IN THE FIRE WEATHER PLANNING FORECAST.  
THE MOST SIGNIFICANT FIRE WEATHER CONCERN WILL BE THUNDERSTORM  
POTENTIAL SUNDAY NIGHT THROUGH MIDWEEK. MODELS HAVE NOT SHOWN VERY  
GOOD RUN TO RUN CONTINUITY, WITH THE LATEST MODELS SHOWING THE UPPER  
LOW DIGGING FURTHER SOUTH OFFSHORE NORTHERN CA BY MONDAY, LINGERING  
THERE THROUGH TUESDAY, THEN EJECTING NORTHEAST ON WEDNESDAY. THIS  
SOLUTION WILL LIKELY RESULT IN THE GREATEST DEEP LAYER MOISTURE AND  
INSTABILITY REMAINING SOUTH OF CENTRAL OREGON THROUGH TUESDAY. WILL  
RETAIN SLIGHT CHANCES OF THUNDERSTORMS FOR MOST OF CENTRAL OREGON,  
WITH LOW END CHANCES FOR MONDAY AFTERNOON FOR FIRE WEATHER ZONES 611  
AND 642.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
PDT 66 97 62 92 / 0 0 0 0  
ALW 70 99 66 94 / 0 0 0 0  
PSC 66 100 63 95 / 0 0 0 0  
YKM 68 97 62 95 / 0 0 10 0  
HRI 67 99 64 95 / 0 0 0 0  
ELN 65 88 57 91 / 0 0 0 0  
RDM 56 94 57 91 / 0 0 20 10  
LGD 58 94 58 91 / 0 0 10 10  
GCD 60 95 61 94 / 0 0 20 20  
DLS 70 93 65 95 / 0 0 0 0  
 

 
   
PDT WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
WA...NONE.  

 
 

 
 
78/93/80  
 
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