High Wind in California, November 18 to 21, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
216 PM PST SUN NOV 18 2012

.SHORT TERM...TONIGHT INTO WEDNESDAY...A STRONG STORM WILL BRING VERY WET AND
WINDY CONDITIONS TO MOST OF THE FORECAST AREA TONIGHT THROUGH
TUESDAY. FLOODING IS A CONCERN FOR AREAS FROM THE COASTAL MOUNTAINS
WEST TO THE COAST. ADDITIONALLY...HIGH WINDS ARE EXPECTED AT THE
COAST...MOUNTAINS...AND AREAS EAST OF THE CASCADES. THE TWO MAIN
IMPACTS ARE DESCRIBED BELOW IN GREATER DETAIL.

PRECIPITATION AND POTENTIAL FLOODING...SEVERAL PIECES OF DATA
SUGGEST AN ANOMALOUSLY HIGH RAINFALL EVENT FOR THIS TIME OF YEAR.
FIRST...PRECIPITABLE WATER IMAGERY SHOWS AN ATMOSPHERIC RIVER
STREAMING IN FROM THE EASTERN PACIFIC WITH PW VALUES OF 1.2 INCHES.
THIS...ACTING UPON A SLOW-MOVING FRONT...WILL FEED HIGH
PRECIPITATION RATES TOMORROW INTO TUESDAY. ADDITIONALLY...ESRL REFORECAST
ANALOGS SUGGEST HIGH CONFIDENCE THAT THIS PRECIPITATION EVENT WILL
BE IN THE TOP 10 PERCENT FOR THIS TIME OF YEAR. LASTLY...MODEL
AGREEMENT AND CONSISTENCY SUPPORT HIGH RAINFALL TOTALS. WE HAVE
ENSURED QPF IN CURRY COUNTY TERRAIN EXCEEDS MODEL PROJECTIONS...AS
IS USUALLY THE CASE IN SIGNIFICANT PRECIPITATION EVENTS...AND WE
HAVE TRENDED SOMEWHAT HIGHER ELSEWHERE NEAR THE COAST PER THE
LATEST 12Z GFS SOLUTION.

RAINFALL WILL INCREASE AT THE COAST THROUGH THE NEXT 24 HOURS...AND
WILL PEAK IN INTENSITY MONDAY NIGHT INTO TUESDAY MORNING WITH 4
INCHES OF RAIN AT THE COAST IN A 24 HOUR PERIOD...AND UP TO 8 INCHES
IN THE COAST RANGE. THIS IS THE TIME WHERE SMALL STREAMS AND CREEKS
COULD OVERFLOW THEIR BANKS...AND ROAD SLUMPS AND LANSLIDES ARE
POSSIBLE AS WELL. PLEASE SEE THE AREAL FLOOD WATCH AT FFAMFR FOR
MORE DETAILS ON THIS IMPACT. ADDITIONALLY...THE SOUTH FORK OF THE
COQUILLE RIVER AT MYRTLE POINT HAS THE POTENTIAL TO FLOOD BY TUESDAY
MORNING. A FLOOD WATCH HAS BEEN ISSUED FOR THIS...ALSO AT FFAMFR.

AREAS EAST OF THE CASCADES AND WEST SIDE VALLEY TOWNS LIKE MEDFORD
AND ROSEBURG WILL GET RAINFALL AS WELL DURING THE NEXT SEVERAL
DAYS...BUT FLOODING IS NOT LIKELY. IN FACT...DUE TO VERY STRONG
DOWNSLOPING WINDS IN MEDFORD ON MONDAY...ONLY VERY INTERMITTENT
RAINFALL IS LIKELY THERE...WITH A BETTER CHANCE FOR SIGNIFICANT
RAINFALL TUESDAY.

PRECIPITATION WILL TAPER OFF DURING THE DAY ON WEDNESDAY BUT SNOW
LEVELS WILL DECREASE AS WELL. AT THIS POINT...THE ONLY
ACCUMULATING SNOWFALL IS EXPECTED ABOVE 5000 FEET LATE TUESDAY
NIGHT INTO WEDNESDAY. THEREFORE...THOSE TRAVELING OVER HWY 140 AT LAKE
OF THE WOODS CAN EXPECT SOME SNOWFALL. OTHERWISE...BE PREPARED FOR
WET TRAVEL ON WEDNESDAY.

.WIND ISSUES...AIDED BY A 130KT PLUS UPPER JET, A PAIR OF FRONTS
WILL MOVE THROUGH THE PACNW OVER THE NEXT 36 HOURS, WITH THE FIRST
COMING IN THIS AFTERNOON FOLLOWED BY A VERY POTENT FRONT LATER
MONDAY. WIND WILL BE ONE OF THE BIGGEST IMPACTS FROM THESE FRONTS.
THE FORECAST REMAINS LARGELY ON TRACK FOR INCREASINGLY WINDY WEATHER
OVER THE AREA CULMINATING ON MONDAY AFTERNOON. CONFIDENCE HAS
INCREASED TO THE POINT THAT ALL HIGH WIND WATCHES FOR MONDAY WILL BE
UPGRADED TO HIGH WIND WARNINGS THIS AFTERNOON. THE WINDIEST
LOCATIONS, THOSE WITH WARNINGS, WILL BE AT THE COAST...SHASTA
VALLEY...EAST SIDE AND OVER THE HIGHER ELEVATIONS IN THE MOUNTAINS.
MUCH OF THE REST OF THE AREA WILL BE UNDER WIND ADVISORIES TOMORROW
AFTERNOON, AND THIS INCLUDES MEDFORD, KLAMATH FALLS, AND ROSEBURG.

TODAY'S FRONT WILL ALSO PACK SOME WIND, AND THE HIGH WIND WARNING
REMAINS IN EFFECT FOR THE COAST WITH ADVISORIES CONTINUING IN THE
SHASTA VALLEY AND PORTIONS OF THE EAST SIDE. THE REST OF THE AREA
WILL SEE BREEZY TO BRIEFLY WINDY CONDITIONS AS THE FRONT GOES
THROUGH LATE THIS AFTERNOON OR THIS EVENING, BUT WINDS SHOULD STAY
BELOW ADVISORY CRITERIA FOR MOST LOCATIONS WITH THIS FRONT.

THE FRONT WILL TAKE SOME TIME TO GET THROUGH OUR AREA AND WINDS WILL
CONTINUE INTO TUESDAY OVER THE EAST SIDE. ANY NECESSARY HEADLINES
FOR TUESDAY WILL BE ADDRESSED BY SUBSEQUENT SHIFTS. -WRIGHT

.LONG TERM...THANKSGIVING DAY INTO SUNDAY...CURRENT OPERATIONAL
MODELS SUGGEST MOSTLY DRY WEATHER FROM THURSDAY INTO SATURDAY. A
FRONTAL BOUNDAY MAY SAG INTO THE COAST AND UMPQUA BASIN ON
SATURDAY NIGHT INTO SUNDAY...PROVIDING A CHANCE FOR RAINFALL
THERE. WE HAD ADJUSTED THE EXTENDED FORECAST TO TREND DRIER PER
RECENT MODEL SOLUTIONS.

&&

.AVIATION...A STRONG FRONT IS APPROACHING THE COAST THIS MORNING AND
WILL MOVE ONSHORE THIS AFTERNOON AND INLAND THIS EVENING. CONDS
HAVE IMPROVED TO MVFR IN WEST SIDE VALLEYS AS SOUTHEAST WINDS
ARE INCREASING AND MIXING OUT THE FOG. ELSEWHERE, IT IS MOSTLY
VFR BUT MVFR CONDS CURRENTLY AT THE COAST WILL SPREAD INLAND
THROUGH THE UMPQUA AS THE FRONT APPROACHES. ALSO, WE WILL BE
SEEING INCREASING WIND SHEAR AT ALL WEST SIDE TERMINALS UNTIL
WINDS MIX DOWN INTO THE VALLEYS LATER THIS AFTERNOON. EAST SIDE
WILL BE BREEZY AND VFR THROUGH THIS EVENING. MOUNTAINS WILL BECOME
INCREASINGLY OBSCURED AND WILL BE TOTALLY OBSCURED THIS EVENING
THROUGH TOMORROW. VERY WINDY AND WET CONDITIONS ARE EXPECTED MOST
AREAS, INCLUDING ALL THE TERMINALS BY TOMORROW AFTERNOON. -WRIGHT

&&

.MARINE...A FRONTAL BOUNDARY OFFSHORE WILL STALL TONIGHT AS SURFACE
HIGH PRESSURE STRENGTHENS OVER NORTHERN CALIFORNIA. THIS WILL
STRENGTHEN THE PRESSURE GRADIENT OVER THE COASTAL WATERS TONIGHT
INTO MONDAY RESULTING IN VERY STRONG SOUTH WINDS. GALE CONDITIONS
THIS EVENING WILL RISE TO STORM FORCE LATER TONIGHT INTO MONDAY AS A
LOW-LEVEL COASTAL JET SETS UP. IT ALMOST GOES WITHOUT SAYING THAT
SEAS WILL BE EXTREMELY DANGEROUS AND ANY SMALL CRAFT SHOULD REMAIN
IN PORT. EVEN COMMERCIAL VESSELS SHOULD CONSIDER REMAINING IN PORT
OR TAKING SHELTER THERE UNTIL THE STORM EASES. THE FRONT WILL
FINALLY GET A PUSH INLAND MONDAY NIGHT, WITH STORM CONDITIONS
SUBSIDING, BUT HIGH END SMALL CRAFT OR LOW END GALE CONDITIONS WILL
PERSIST THROUGH TUESDAY NIGHT. SEAS WILL LIKELY REMAIN HAZARDOUS
THROUGH AT LEAST THURSDAY. SPILDE

&&

.CLIMATE...IF FORECAST RAINFALL FOR THE COAST VERIFIES FOR MONDAY
NIGHT INTO TUESDAY...THIS WILL BE A TOP TEN EVENT FOR NOVEMEBER IN
TERMS OF 24 HOUR RAINFALL.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING FROM 10 AM TO 10 PM PST MONDAY FOR ORZ030-031.
     WIND ADVISORY UNTIL 10 AM PST MONDAY FOR ORZ030-031.
     HIGH WIND WARNING FROM 10 AM TO 10 PM PST MONDAY FOR ORZ027-028.
     FLOOD WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING FOR
     ORZ021>024.
     HIGH SURF WARNING UNTIL 10 PM PST MONDAY FOR ORZ022.
     HIGH WIND WARNING UNTIL 10 PM PST MONDAY FOR ORZ021-022.
     WIND ADVISORY FROM 10 AM TO 7 PM PST MONDAY FOR ORZ023-025-026.
     HIGH WIND WARNING FROM 10 AM TO 7 PM PST MONDAY FOR ORZ024.
     WIND ADVISORY FROM 10 AM TO 10 PM PST MONDAY FOR ORZ029.

CA...HIGH WIND WARNING FROM 10 AM TO 10 PM PST MONDAY FOR CAZ083.
     WIND ADVISORY FROM 10 AM TO 10 PM PST MONDAY FOR CAZ084.
     WIND ADVISORY FROM 10 AM TO 10 PM PST MONDAY FOR CAZ082.
     HIGH WIND WARNING FROM 10 AM TO 10 PM PST MONDAY FOR CAZ081.
     WIND ADVISORY UNTIL 10 AM PST MONDAY FOR CAZ081.
     WIND ADVISORY FROM 10 AM TO 10 PM PST MONDAY FOR CAZ085.

PZ...STORM WARNING UNTIL 10 PM PST MONDAY FOR PZZ350-356-370-376.
     HAZARDOUS SEAS WARNING UNTIL 10 PM PST TUESDAY FOR
     PZZ350-356-370-376.

SK