Damaging Winds in Oregon, August 12, 2014

AREA FORECAST DISCUSSION...UPDATED AVIATION DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1020 AM PDT TUE AUG 12 2014

.SHORT TERM...UPPER LOW THAT WAS OFF THE CALIFORNIA COAST THE PAST
FEW DAYS IS LIFTING NORTHEAST TODAY. IT WILL MOVE ACROSS OREGON AND
WASHINGTON WITH SHOWERS AND THUNDERSTORMS. DYNAMICS WITH THE LOW AND
ASSOCIATED JET WILL LIKELY RESULT IN SOME STRONG STORMS. EXPECT THE
ACTIVITY TO START IN CENTRAL OREGON LATER THIS MORNING THEN MOVE
NORTHWARD THROUGH THE AFTERNOON AND EXIT THE FORECAST AREA TO THE
NORTH DURING THE EVENING. ASIDE FROM THE STORMS EXPECT MOSTLY CLOUDY
SKIES AND COOLER TEMPERATURES TODAY. ANOTHER STRONG UPPER LOW WILL
THEN MOVE INTO THE PACIFIC NORTHWEST WEDNESDAY AND THURSDAY WITH
ADDITIONAL SHOWERS AND THUNDERSTORMS. 94

&&

.PREV DISC... /ISSUED 449 AM PDT TUE AUG 12 2014/

SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...SHOWERS CONTINUE TO
MOVE NORTHWARD ACROSS THE CWA THIS MORNING. LIGHTNING ACTIVITY HAS
DECREASED TO ALMOST NO LIGHTNING. THESE SHOWERS ARE PRODUCING SOME
LIGHT SPRINKLES TO AREAS SUCH AS KPDT AND KHRI. OTHER LOCATIONS ARE
LIKELY RECEIVING LIGHT SPRINKLES AS WELL. THE ATMOSPHERE WILL REMAIN
UNSTABLE OVERNIGHT SO THE SHOWERS ARE EXPECTED TO CONTINUE THIS
MORNING. THUNDERSTORMS WILL DEVELOP AND INCREASE IN AREAL COVERAGE
AGAIN TODAY...ESPECIALLY THIS AFTERNOON AND EVENING. THERE IS SOME
SHEAR AND PLENTY OF CAPE AND NEGATIVE LI'S TO SUPPORT SOME STRONG TO
SEVERE STORMS. SPC HAS THE CWA IN A SLIGHT CHANCE OF SEVERE
THUNDERSTORMS TODAY...AND AGAIN ON WEDNESDAY. ADDED GUSTY WINDS...
HEAVY RAINFALL AND SMALL HAIL TO THUNDERSTORMS ON WEDNESDAY AND LEFT
THEM IN THE FORECAST FOR TODAY. AN UPPER LOW PRESSURE SYSTEM ALONG
THE NORTHERN CALIFORNIA COAST WILL OPEN UP TO A TROUGH TODAY AND
SWING NORTHWARD ACROSS THE CWA THIS AFTERNOON AND EVENING. THIS WILL
ACT AS THE TRIGGER FOR THUNDERSTORM DEVELOPMENT TODAY. THE NAM MODEL
HAS ABUNDANT PRECIPITATION AND WIND SWINGING UP IN WHAT APPEARS TO
BE A SQUALL LINE LATER TODAY AND THIS EVENING. THIS WILL ESPECIALLY
BE TRUE ALONG THE CASCADE EAST SLOPES WHERE UPSLOPE EFFECTS WILL
ENHANCE THUNDERSTORM DEVELOPMENT. MAIN CONCERNS WITH THUNDERSTORMS
TODAY AND WEDNESDAY WILL BE STRONG GUSTY WINDS...SMALL HAIL AND
FREQUENT LIGHTNING. THERE MAY ALSO BE BRIEF HEAVY RAIN WITH
THUNDERSTORMS. THE HEAVY RAIN POTENTIAL IS ESPECIALLY ADVERTISED BY
THE NAM MODEL. DUE TO CLOUD COVER AND PRECIPITATION TEMPERATURES
WILL BE COOLER TODAY AND THEN EVEN COOLER ON WEDNESDAY. EXPECT HIGH
TEMPERATURES TO BE IN THE LOWER 90S IN THE LOWER ELEVATIONS TO THE
70S AND 80S IN THE MOUNTAINS TODAY. THIS WILL COOL DOWN TO THE MID
TO UPPER 80S IN THE LOWER ELEVATIONS WITH 70S IN THE MOUNTAINS FOR
WEDNESDAY. THERE WILL BE GUSTY WINDS IN THE LOWER COLUMBIA BASIN AND
BLUE MOUNTAIN FOOTHILLS AS WELL AS THE EASTERN COLUMBIA RIVER GORGE
THIS AFTERNOON AND EVENING. ON WEDNESDAY WINDS WILL MAINLY INCREASE
TO ABOVE 15 KTS IN THE EASTERN COLUMBIA RIVER GORGE AND WESTERN
OREGON PORTION OF THE LOWER COLUMBIA BASIN. ELSEWHERE WINDS ARE
EXPECTED TO REMAIN LIGHT FOR THE NEXT COUPLE OF DAYS. 88

LONG TERM...THURSDAY THROUGH MONDAY...AN UPPER LOW WILL SLOWLY
DRIFT NORTHEAST FROM CENTRAL OREGON TO NORTHEAST WASHINGTON THURSDAY
THROUGH FRIDAY. THIS LOW WILL KEEP CONDITIONS UNSTABLE ENOUGH TO
SUPPORT CONTINUED CHANCES OF SHOWERS AND THUNDERSTORMS THURSDAY
THROUGH FRIDAY. THE SHOWER AND STORM THREAT WILL BE AREAWIDE
THURSDAY AND THURSDAY EVENING. BY FRIDAY, THE SHOWER AND STORM
THREAT WILL BECOME LIMITED TO AREAS AROUND THE WASHINGTON CASCADE
EAST SLOPES AND FROM THE JOHN DAY-OCHOCO HIGHLANDS NORTH TO THE BLUE
MOUNTAINS, BLUE MTN FOOTHILLS, THE GRANDE RONDE VALLEY AND WALLOWA
COUNTY. THIS UPPER LOW WILL BE REPLACED BY A DRY WEST-NORTHWEST
UPPER LEVEL FLOW LATE FRIDAY NIGHT INTO SATURDAY. THIS FLOW LOOKS TO
HOLD INTO EARLY NEXT WEEK, THUS WILL CONTINUE TO INDICATE FAIR AND
DRY CONDITIONS SATURDAY THROUGH MONDAY. HIGH TEMPS WILL BE NEAR TO
SLIGHTLY BELOW SEASONAL THURSDAY AND FRIDAY DUE TO THE UPPER LOW
OVER THE REGION. HIGH TEMPS ARE EXPECTED TO WARM TO SLIGHTLY ABOVE
SEASONAL SATURDAY THROUGH MONDAY. LOW TEMPS WILL GENERALLY BE NEAR
TO SLIGHTLY ABOVE SEASONAL THROUGH THE PERIOD. 90

AVIATION...18Z TAFS...VFR CONDITIONS WILL GENERALLY PREVAIL OVER
THE NEXT 24 HOURS. AN UPPER LOW OVER NORTHWESTERN CALIFORNIA WILL
MOVE ACROSS THE REGION THIS AFTERNOON.  THUNDERSTORMS SHOULD AFFECT
KRDM AND KBDN FIRST, THEN SPREAD NORTH TO AFFECT OUR OTHER SITES
THROUGH THE AFTERNOON. BRIEF MVFR CONDITIONS MAY BE POSSIBLE DUE TO
HEAVY RAIN. WINDS WILL GENERALLY RUN 5-15 KTS...BUT COULD GUST 30-40
KT NEAR TSTMS. 91

FIRE WEATHER...THUNDERSTORM ACTIVITY WILL INCREASE TODAY WITH
ABUNDANT LIGHTNING AS MOISTURE AND INSTABILITY ROTATES INTO THE
REGION FROM A LOW PRESSURE SYSTEM OFF THE NORTHERN CALIFORNIA COAST.
EVEN THOUGH SOME THUNDERSTORMS COULD PRODUCE HEAVY RAIN THE THREAT
OF NEW FIRE STARTS IS HIGH ON THE EDGES OF THUNDERSTORM CELLS WHERE
THERE WILL BE LITTLE PRECIPITATION. AS A RESULT A RED FLAG WARNING
REMAINS IN EFFECT FOR THE ENTIRE FIRE WEATHER DISTRICT BEGINNING
TODAY THROUGH THIS EVENING. THEN AS THE THUNDERSTORMS BECOME MORE
CONCENTRATED TO THE NORTH AND EAST AS THE UPPER LOW LIFTS TO THE
NORTHEAST THE RED FLAG WARNINGS WILL DROP OFF IN SOUTHERN AREAS AND
WILL REMAIN IN NORTHERN AREAS FROM THE BLUE MOUNTAIN FOOTHILLS
NORTHWARD UNTIL WEDNESDAY LATE EVENING. 88

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  87  62  83  60 /  60  60  30  30
ALW  90  65  86  63 /  60  60  40  30
PSC  92  64  87  63 /  60  60  30  30
YKM  89  63  83  61 /  60  60  30  30
HRI  91  63  86  62 /  60  60  30  30
ELN  88  61  80  59 /  60  60  30  30
RDM  80  54  73  51 /  60  40  40  30
LGD  84  58  79  56 /  60  60  40  40
GCD  83  55  80  53 /  70  40  40  30
DLS  86  64  80  62 /  60  60  30  30

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING
     ORZ049-050-502-505-506-509-511.

     RED FLAG WARNING UNTIL 11 PM PDT WEDNESDAY
     ORZ041-044-503-507-508-510.

WA...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING WAZ030.

     RED FLAG WARNING UNTIL 11 PM PDT WEDNESDAY WAZ024-026>029-521.

     RED FLAG WARNING UNTIL 5 PM PDT WEDNESDAY WAZ520.

&&

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

94

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
137 PM PDT TUE AUG 12 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0115 PM     HEAVY RAIN       3 N TERREBONNE          44.39N 121.18W
08/12/2014  U0.00 INCH       DESCHUTES          OR   TRAINED SPOTTER

            WATER ACROSS THE ROAD ON HIGHWAY 97...IMPACTING TRAFFIC
            FLOW. GUSTY WINDS EST 40 MPH ALSO.

&&

MMURPHY