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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
848 PM PDT FRI JUL 3 2015

.UPDATE...MONSOONAL MOISTURE WRAPPING AROUND AN UPPER LOW OFF THE
CALIFORNIA COAST HAS CAUSED THUNDERSTORM ACTIVITY TO KICK OFF
OVER NORTHERN CALIFORNIA...NEVADA AND SOUTHERN OREGON TODAY. THIS
ACTIVITY WILL TAPER OFF WITH THE LOSS OF DAYTIME HEATING AND BRING
SOME MID TO UPPER LEVEL CLOUDS OVERNIGHT. MEANWHILE...A PASSING
UPPER LEVEL TROUGH OVER SOUTHERN BRITISH COLUMBIA HAS STARTED TO
SUPPRESS THE RIDGE THAT HAS BROUGHT RECORD HEAT TO THE AREA. HAVE
ALLOWED THE HEAT ADVISORY TO EXPIRE TONIGHT AS SLIGHTLY
COOLER...ALBEIT ABOVE NORMAL...TEMPERATURES ARE FORECASTED. RED
FLAG WARNINGS REMAIN IN EFFECT THROUGH THE FOURTH OF JULY WEEKEND
AS VERY WARM AND DRY CONDITIONS WILL OCCUR COMBINED WITH INCREASED
BREEZES. BIEDA

.AVIATION...06Z TAFS...VFR CONDITIONS WILL OCCUR OVER THE NEXT 24
HOURS WITH SCT CIRRUS AOA 10K FT AGL OVER KBDN AND KRDM FROM
THUNDERSTORM BLOWOFF AND INCREASING UPPER LEVEL MOISTURE BROUGHT
IN FROM THE SOUTH. WINDS BTWN 5 TO 15 KTS WILL OCCUR OVERNIGHT
TONIGHT BECOMING NORTHERLY 10 TO 20 KTS AFT 04/21Z DUE TO PASSING
SHORTWAVE TROUGH. BIEDA

&&

.FIRE WEATHER...RED FLAG WARNINGS ARE CURRENTLY IN EFFECT FOR 
PORTIONS OF THE LOWER COLUMBIA BASIN AND CENTRAL OREGON...INCLUDING 
THE KITTITAS VALLEY, YAKIMA VALLEY, AND THE EASTERN COLUMBIA RIVER. 
WINDS ARE CURRENTLY 15-25 MPH IN THE EASTERN COLUMBIA RIVER GORGE 
AND ARE INCREASING SLIGHTLY IN NORTH CENTRAL OREGON. WINDS WILL 
LIKELY INCREASE TO AROUND 10-15 MPH IN THE AREAS UNDER THE WARNING 
OVER THE NEXT SEVERAL HOURS...AND A FEW SPOTS WILL OBSERVE 15-20 MPH 
WINDS.  WINDS ARE EXPECTED TO BE LESS ON INDEPENDENCE DAY THAN 
TODAY...BUT STILL ON THE LOW END OF WARNING CRITERIA.  THE NEXT 
CONCERN FOR FIRE WEATHER WILL BE ON THE THUNDERSTORM POTENTIAL NEXT 
WEEK.  THE FAR SOUTHERN ZONES WILL HAVE A SLIGHT CHANCE OF 
THUNDERSTORMS MON AND TUES...AND THE SLIGHT CHANCE WILL EXTEND A 
LITTLE FARTHER NORTH ON WED.  12Z GFS AND ECMWF WOULD INDICATE A 
BETTER POTENTIAL FOR THUNDERSTORMS IN CENTRAL AND NE OREGON ON 
THURSDAY. FOR DETAILS...REFER TO THE LONG TERM DISCUSSION.  WISTER

&&

.PREV DISCUSSION... /ISSUED 224 PM PDT FRI JUL 3 2015/ 

SHORT TERM...TONIGHT THROUGH MONDAY...HIGH PRESSURE OVER THE REGION 
WILL WEAKEN SLIGHTLY AND BE SUPPRESSED BY AN UPPER LEVEL TROUGH 
MOVING THROUGH CANADA THIS WEEKEND. THIS WILL RESULT IN SOME 
SLIGHTLY COOLER YET STILL ABOVE NORMAL TEMPERATURES THROUGH THE 
WEEKEND. THE TROUGH WILL ALSO AIDE IN PRODUCING SOME LOCALLY BREEZY 
WINDS ALONG THE EAST SLOPES OF THE CASCADES SATURDAY. CONTINUE TO 
WATCH THE CLOSED UPPER LEVEL LOW PRESSURE SYSTEM OFF THE COAST OF 
CALIFORNIA FOR ANY SIGNS OF IT ADVECTING MOISTURE INTO THE REGION 
FOR POSSIBLE THUNDERSTORMS. AT THIS POINT THE MOISTURE LOOKS TO 
REMAIN SOUTH OF THE FORECAST AREA THROUGH SUNDAY. BY MONDAY MODELS 
BRING IT A LITTLE FURTHER AND SOUTHERN DESCHUTES COUNTY COULD BE ON 
THE FRINGE.
 
LONG TERM...MONDAY NIGHT THROUGH FRIDAY NIGHT...UPPER LEVEL LOW
OFF THE CALIFORNIA COAST WILL SLOWLY PROGRESS INLAND THROUGH MID
WEEK...WITH A RIDGE OF HIGH PRESSURE OFF TO THE SOUTHEAST. SLIGHT
CHANCE THUNDERSTORMS WILL BE POSSIBLE ACROSS CENTRAL OREGON ON
TUESDAY AND WEDNESDAY. BY THURSDAY COVERAGE WILL INCREASE TO
NORTHEAST OREGON AS THE LOW IS EXPECTED TO BE OVER THE OR/NV/CA
BOARDER. BASED ON THE GFS POSITION OF THE LOW THURSDAY
EVENING...CENTRAL AND NORTHEAST OREGON WOULD BE SET UP IN THE
DEFORMATION ZONE...AND THE MODEL CURRENTLY SUGGESTS A MODERATE
AMOUNT OF PRECIPITATION (0.50"-1.00") OVER THESE HIGHER TERRAIN
AREAS. WILL STILL GO WITH ONLY A SLIGHT CHANCE AS MODELS HAVE JUST
NOW SHIFTED TO THIS SOLUTION VERSUS A STABLE AND DRIER
NORTHWESTERLY FLOW. AS THE LOW EXITS THE AREA FRIDAY
NIGHT...EXPECT DRY WESTERLY FLOW TO SET IN AND PERHAPS AN INCREASE
IN WINDS. GFS INDICATES MUCH COOLER AIR AND HIGHER SURFACE
HUMIDITIES POSSIBLE WITH THIS WESTERLY FLOW...SO NOT CONFIDENT
THAT THE POTENTIAL STRONG WINDS WILL POSE FIRE WEATHER ISSUES.
WEBER

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  66 100  66  98 /   0   0   0   0 
ALW  72 100  72  97 /   0   0   0   0 
PSC  69 102  69 100 /   0   0   0   0 
YKM  68  97  69  94 /   0   0   0   0 
HRI  69 101  67  99 /   0   0   0   0 
ELN  69 101  66  98 /   0   0   0   0 
RDM  55  95  58  94 /   0   0   0   0 
LGD  56  94  60  92 /   0   0   0   0 
GCD  58  98  60  96 /   0   0   0   0 
DLS  69  99  70 100 /   0   0   0   0 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 8 PM PDT SATURDAY FOR ORZ610-639>641.

WA...RED FLAG WARNING UNTIL 8 PM PDT SATURDAY FOR WAZ639.

     RED FLAG WARNING UNTIL 9 AM PDT SUNDAY FOR WAZ675.

&&

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON

$$

98/89/98

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