Area Forecast Discussion
Issued by NWS Medford, OR

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000
FXUS66 KMFR 020407
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
907 PM PDT FRI AUG 1 2014

.DISCUSSION...AN ISOLATED STRONG THUNDERSTORM NEAR HIGHWAY 20 IN
EXTREME NORTHEAST LAKE COUNTY HAS WEAKENED SIGNIFICANTLY IN THE
LAST SEVERAL MINUTES AT THE SAME TIME SEVERAL LIGHTNING STRIKES
WERE OBSERVED WITHIN THE CELL. PROBABLY LIKELY DUE TO THE STORM
COLLAPSING. ALTHOUGH THERE HAVE BEEN NO CONFIRMED REPORTS, SUSPECT
THIS ONE COULD HAVE PRODUCED SOME LARGE HAIL. AROUND 815 PM PDT WE
WERE SEEING CLOSE TO 66 DBZ NEAR 27000 FEET MSL. CURRENT RADAR
SHOWS ANOTHER CELL THAT WAS STARTING TO FORM, BUT THIS HAS ALSO
WEAKENED AND NOW THAT WE ARE LOSING DAYTIME HEATING, SO WE DON`T
THINK WE`LL SEE MUCH MORE ACTION FOR THE REST OF THE OVERNIGHT
PERIOD. THE 0Z NAM AND GFS ARE STARTING TO COME IN AND BOTH SHOW
WEAK SHORTWAVES MOVING THROUGH DURING THE DAY SATURDAY WITH MOST
OF THE INSTABILITY EAST OF THE CASCADES IN THE NORTHERN HALF OF
LAKE AND KLAMATH COUNTIES AND POSSIBLY A FEW ISOLATED STORMS NEAR
THE SHASTA TRINITY. WE`LL TAKE A CLOSER LOOK AT THE THIS TONIGHT.
-PETRUCELLI


&&

.AVIATION...EXPECT AREAS OF IFR/MVFR CIGS TO REDEVELOP IN THE
EARLY EVENING WITH IFR CIGS BECOMING WIDESPREAD OVERNIGHT AND
CONTINUING INTO SATURDAY MORNING FROM CAPE BLANCO NORTH AND NEAR
BROOKINGS SOUTHWARD.  INLAND...VFR CONDITIONS WILL PREVAIL TODAY.
ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS MAY
PRODUCE AREAS OF TURBULENCE WITH GUSTY OUTFLOW WINDS AND HAIL IN
AREAS FROM THE CASCADES EASTWARD IN SOUTHERN OREGON. /CC


&&

.MARINE...UPDATED 230 PM PDT 1 AUG 2014...

THE CURRENT PATTERN...WITH SOME SLIGHT DAY-TO-DAY VARIATION...WILL
PERSIST THROUGH WEDNESDAY...AND POSSIBLY THROUGH FRIDAY. OFFSHORE
HIGH PRESSURE AND A THERMAL TROUGH OVER NORTHERN CALIFORNIA WILL
COMBINE TO MAINTAIN STRONG NORTHERLY WINDS WITH STEEP TO VERY STEEP
WIND WAVE DOMINATED SEAS. THE STRONGEST WINDS AND STEEPEST SEAS
WILL OCCUR IN THE AFTERNOON AND EVENING HOURS AND FROM CAPE BLANCO
SOUTH...ESPECIALLY IN THE OUTER PORTION OF THE WATERS WHERE AREAS OF
GALES ARE EXPECTED. /DW


&&

.PREV DISCUSSION... /ISSUED 145 PM PDT FRI AUG 1 2014/

DISCUSSION...THUNDERSTORMS AND SMOKE (AIR QUALITY) ARE THE PRIMARY
CONCERNS. MUCH OF SOUTHWEST OREGON WAS IMPACTED BY SMOKE LAST YEAR
AT THIS TIME OF YEAR AS LIGHTNING-INITIATED FIRES BROKE OUT THE
MORNING OF JULY 26, 2013. AT THAT TIME THE WORST SMOKE WAS OVER
THE REGION FOR A COUPLE OF WEEKS. TODAY IS A REMINDER THAT FIRE
WEATHER IS THE "SEVERE" WEATHER IN THIS REGION DURING THE SUMMER.

WE HAVE A NUMBER OF BIG EVENTS OCCURRING THIS WEEKEND IN OUR
FORECAST AREA. THERE IS THE CAPE BLANCO COUNTRY MUSIC FESTIVAL
NEAR CAPE BLANCO STATE PARK, DUNEFEST IN WINCHESTER BAY, AND THE
CASCADE LAKES RELAY RUN FROM DIAMOND LAKE TO SILVER LAKE TO LA
PINE AND BEND. THE TWO COASTAL EVENTS WILL HAVE COOL TEMPERATURES,
CLOUDS AT TIMES ESPECIALLY AT DUNEFEST, AND BOTH EVENTS WILL
EXPERIENCE GUSTY WINDS. FOR TODAY, THE RELAY RUN WILL HAVE
ISOLATED AFTERNOON AND EVENING THUNDERSTORMS ESPECIALLY ACROSS THE
FREMONT-WINEMA NATIONAL FOREST HIGHER ELEVATIONS.

IT LOOKS LIKE THE ATMOSHERIC INSTABILITY AND DEEPER MOISTURE WILL
OCCUR ACROSS THE OREGON CASCADES AND OREGON EAST SIDE DURING THE
AFTERNOONS AND EVENINGS THIS WEEKEND. IT DOES NOT LOOK LIKE THERE
WILL BE ENOUGH LIGHTNING TO WARRANT A RED FLAG WARNING BUT THIS
PATTERN WILL BE PERSISTENT. IT IS ALSO POSSIBLE THAT ONE OF THE
LARGE FIRES IN FAR NORTHERN CALIFORNIA AND NEAR THE OREGON-
CALIFORNIA BORDER COULD INITIATE ITS OWN THUNDERSTORM WITH
PYROCUMULUS CLOUDS BUILDING.

HAVE CONTINUED AREAS OF SMOKE IN THE FORECAST THROUGH THE WEEKEND
BUT EXPECT THAT SMOKE WILL PERSIST INTO NEXT WEEK AS NO WIDESPREAD
RAIN AND COOLING WILL OCCUR.

THE PATTERN CHANGES TO MORE MONSOONAL AS THE NAM, GFS, AND ECMWF
ALL SHOW DEEPER MOISTURE ADVECTING INTO NORTHEAST CALIFORNIA AND
SOUTH CENTRAL AND SOUTHEAST OREGON BY LATE SUNDAY INTO MONDAY. THE
GFS PUSHES THIS MOISTURE FARTHER WEST THAN THE ECMWF. THE MODELS
BOTH SHOW INSTABILITY ACROSS THE REGION MONDAY AND TUESDAY WITH
LESS INSTABILITY WEDNESDAY AND THURSDAY SO ISOLATED THUNDERSTORMS
REMAIN IN THE FORECAST. THERE COULD BE MORE CLOUDS AROUND IN THE
MONSOON AIRMASS ESPECIALLY MONDAY AND TUESDAY AND THIS COMBINED
WITH SMOKE COULD KEEP HIGH TEMPERATURES LOWER THAN FORECAST SO
THIS WILL HAVE TO BE ASSESSED.
SANDLER



&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...
CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT
     SUNDAY FOR PZZ356-376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT MONDAY
     FOR PZZ350-356-370-376.
     HAZARDOUS SEAS WARNING UNTIL 5 AM PDT MONDAY FOR PZZ356-376.
     GALE WARNING UNTIL 11 PM PDT SUNDAY FOR PZZ376.

$$






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