Area Forecast Discussion
Issued by NWS Pendleton, OR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KPDT 112247 AAA
AFDPDT

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
347 PM PDT FRI JUL 11 2014

UPDATED AVIATION DISCUSSION

.SHORT TERM...TONIGHT THROUGH MONDAY...CONDITIONS WILL BECOME QUITE
HOT THIS WEEKEND, WITH THE HOT CONDITIONS EXTENDING INTO EARLY NEXT
WEEK. HIGH TEMPS IN THE LOWER BASIN, EASTERN GORGE AND THE LOWER
YAKIMA VALLEY WILL EXCEED 102 DEGREES MOST AFTERNOONS FROM SATURDAY
THROUGH TUESDAY. ALSO OVERNIGHT LOWS WILL NOT FALL BELOW 65 DEGREES
AT MANY LOCATIONS WITHIN THESE AREAS. THEREFORE WILL ISSUE A HEAT
ADVISORY STARTING LATE SATURDAY MORNING, RUNNING THROUGH EARLY
TUESDAY EVENING.

AN UPPER LEVEL WAVE ASSOCIATED WITH AN OFFSHORE UPPER LOW WILL DRIFT
NORTH LATE THIS AFTERNOON THROUGH TONIGHT. A BROAD AREA OF CLOUDS
AND MOISTURE IS ASSOCIATED WITH THIS WAVE. SO FAR THUNDERSTORMS HAVE
BEEN LIMITED TO SOUTHWEST OREGON AND AREAS NEAR THE OREGON BORDER ON
THE BACK EDGE OF THE CLOUD BAND. TEMPERATURES HAVE STRUGGLED TO WARM
ACROSS CENTRAL OREGON DUE TO THE CLOUD COVER, THUS SURFACE BASED
THUNDERSTORMS WILL BE LIMITED LATE THIS AFTERNOON. STILL COULD SEE
ISOLATED SHOWERS AND THUNDERSTORMS DRIFT INTO CENTRAL AND
EAST-CENTRAL OREGON THIS EVENING AS THE WAVE MOVES ACROSS THIS AREA.
THE WAVE WILL CONTINUE TO DRIFT NORTH ACROSS THE REGION OVERNIGHT
INTO SATURDAY MORNING. MAINLY EXPECT VARIABLE AMOUNTS OF CLOUDINESS
WITH THIS SYSTEM, BUT COULD SEE A FEW SHOWERS (AIDED BY UPSLOPE
AFFECTS) ALONG THE CASCADE EAST SLOPES. ALSO A STRAY THUNDERSTORM
MAY OCCUR ALONG THE OREGON CASCADE CREST OVERNIGHT. SHOULD SEE A
SLIGHT STABILIZATION OF THE AIR MASS OVER THE AREA SATURDAY
AFTERNOON AND EVENING AS THE WAVE EXITS THE REGION. STILL COULD SEE
A FEW SHOWERS AND THUNDERSTORMS DEVELOP OVER SOME OF THE HIGHER
TERRAIN DUE TO STRONG DAYTIME HEATING. A STRONGER WAVE WILL SWING
TOWARDS THE PACNW COAST SUNDAY, THEN SWING ACROSS THE REGION MONDAY.
SHOWERS AND THUNDERSTORMS SHOULD DEVELOP ALONG AND AHEAD OF THIS
SYSTEM. BEST CHANCES FOR STORMS WILL BE OVER CENTRAL OREGON WHERE
STRONG STORMS PRODUCING GUSTY WINDS AND SMALL HAIL MAY POSSIBLE. 90

.LONG TERM...MONDAY EVENING THROUGH FRIDAY...A PERSISTENT RIDGE OF
HIGH PRESSURE WILL KEEP HEAT AS THE MAIN STORY THROUGH THURSDAY
BEFORE CHANGES START BRINGING IN COOLER TEMPERATURES. MONDAY EVENING
A WEAK TROUGH WILL BE CROSSING ALONG THE CANADIAN BORDER AND WILL
EXIT THE AREA DURING THE EVENING. MOISTURE WITH THE TROUGH AND
HEATING OF THE DAY WILL PROVIDE THE INGREDIENTS FOR A SLIGHT CHANCE
OF THUNDERSTORMS ALONG THE EASTERN OREGON MOUNTAINS IN THE EVENING.
THE STORMS AND SHOWERS WILL BE GONE BY THE OVERNIGHT HOURS. THE
RIDGE WILL QUICKLY REBUILD OFFSHORE AND THERE WILL BE LITTLE
MOISTURE SO THE REGION WILL REMAIN DRY THROUGH WEDNESDAY. MODELS
BEGIN DIVERGING AT THIS POINT AS THE ECMWF MAINTAINS THE RIDGE
THROUGH FRIDAY THOUGH A SYSTEM WELL TO OUR NORTH WILL DEPRESS THE
RIDGE SOUTHWARD AND PROVIDE GRADUAL COOLING. THE GFS SENDS THE RIDGE
EASTWARD ON WEDNESDAY AND BRINGS A DEEP TROUGH TO THE COAST
THURSDAY. THE TROUGH STRENGTHENS FURTHER MOVES ASHORE FRIDAY. THE
ECMWF WOULD KEEP US DRY WHILE THE GFS WOULD LIKELY BRING A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA THURSDAY AND FRIDAY.
GIVEN THE BIG CHANGE IN THE GFS, HAVE LEANED TOWARDS THE ECMWF FOR
NOW AND KEPT A DRY FORECAST. TEMPERATURES WILL REACH 100 TO 105 IN
THE LOWER COLUMBIA BASIN WITH UPPER 80S AND 90S ELSEWHERE TUESDAY
AND WEDNESDAY THEN COOL 2-4 DEGREES THURSDAY. BY FRIDAY,
TEMPERATURES WILL BE BACK TO THE 90S WITH MAINLY 80S IN THE
MOUNTAINS, PERHAPS A FEW DEGREES COOLER THAN THAT IF THE GFS IS
CORRECT. PERRY

&&

.AVIATION...00Z TAFS...VFR CONDITIONS ARE EXPECTED DURING THE NEXT
24 HOURS. HOWEVER...INCREASING SOUTHERLY FLOW HAS CARRIED MONSOON
MOISTURE INTO THE AREA AND THIS WILL ALLOW FOR A SLIGHT CHANCE OF
VICINITY THUNDERSTORMS NEAR KRDM AND KBDN FROM 12/02Z TO 12/05Z AND
VICINITY SHOWERS FROM 12/05Z TO 12/09Z. THERE WILL ALSO BE VICINITY
SHOWERS NEAR KDLS FROM 12/08Z TO 12/13Z. LINGERING MOISTURE AND
INSTABILITY TOMORROW AFTERNOON WILL LEAD TO A SLIGHT CHANCE OF
THUNDERSTORMS OVER THE HIGHER TERRAIN OF THE CASCADES, CENTRAL
OREGON AND THE OCHOCO, STRAWBERRY AND ELKHORN MOUNTAINS AFTER 21Z.
THIS MAY AFFECT KRDM AND KBDN, SO HAVE VCTS IN THE TAFS FOR THEM. IN
GENERAL, AWAY FROM CENTRAL OREGON SKIES WILL BE SCT-BKN ABOVE 10000
FEET THROUGH TOMORROW AFTERNOON. WINDS ARE EXPECTED TO BE AT OR
BELOW 15 KTS DURING THE ENTIRE TAF PERIOD...THOUGH HIGHER AND
ERRATIC GUSTS CAN BE FOUND NEAR THE STRONGER THUNDERSTORMS. PERRY

&&

.FIRE WX...ON SUNDAY...SUBTROPICAL MOISTURE WILL MOVE INTO THE
REGION. THIS IN COMBINATION WITH A WEATHER DISTURBANCE WILL LEAD TO
A CHANCE OF THUNDERSTORMS WITH ABUNDANT LIGHTNING OVER CENTRAL
OREGON. WITH HOT AND DRY CONDITIONS OVER THE LAST SEVERAL DAYS AND
THE STORMS INITIALLY STARTING OUT WITH LITTLE RAINFALL...THERE IS AN
ENHANCED THREAT OF NEW WILDFIRES OVER CENTRAL OREGON. THEREFORE... A
FIRE WEATHER WATCH HAS BEEN ISSUED FOR THE CENTRAL OREGON FIRE ZONES
SUNDAY THROUGH SUNDAY NIGHT. 84

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  61 100  65 103 /   0   0  10  10
ALW  66 100  70 104 /   0   0   0  10
PSC  62 103  66 105 /   0   0   0   0
YKM  63  99  67 101 /   0  10   0  10
HRI  61 102  65 105 /   0   0   0  10
ELN  58 100  62 103 /   0  10  10  10
RDM  54  96  57  98 /  20  20  20  30
LGD  53  95  57  98 /  10  10  10  10
GCD  56  98  63 100 /  20  20  20  20
DLS  65 100  66 104 /   0  20  10  20

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
     ORZ505-506-509>511.

     HEAT ADVISORY FROM 11 AM SATURDAY TO 9 PM PDT TUESDAY ORZ041-044.

WA...HEAT ADVISORY FROM 11 AM SATURDAY TO 9 PM PDT TUESDAY
     WAZ024-027-028.

&&

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

$$

90/83/83/84





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.