Area Forecast Discussion
Issued by NWS Medford, OR

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000
FXUS66 KMFR 010457 CCA
AFDMFR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE MEDFORD OR
955 PM PDT TUE SEP 30 2014

.DISCUSSION....NOT MUCH TO ADD TONIGHT. WITH THE COOLER TEMPERATURES
THE AFTERNOON DEWPOINT CROSS-OVER METHOD INDICATED THAT THERE SHOULD
NOT BE FOG AT THE AIRPORT. HOWEVER, WITH THE WATER TEMPS SLOWER TO
COOL HAVE ADDED PATCHY FOG TO THE ROGUE VALLEY FOR THE MORNING. SVEN

PREVIOUS DISCUSSION...A WEAK UPPER TROUGH WILL MOVE THROUGH THE AREA
THIS EVENING WITH UPPER RIDGING BUILDING WEST OF THE AREA TONIGHT.
CLOUD COVER IS MOSTLY CONFINED TO NORTHERN PART OF THE AREA WILL
DISSIPATE THIS EVENING WITH MOSTLY CLEAR SKIES TONIGHT. MODELS
SUGGEST SUFFICIENT LOW LEVEL MOISTURE EXIST FOR LOW CLOUDS AND
PATCHY FOG TO FORM IN THE UMPQUA BASIN TONIGHT. MEANWHILE SKIES WILL
BE CLEAR EAST OF THE CASCADES WITH LIGHT WINDS, LONGER NIGHTS AND
LOWER DEWPOINTS. THIS WILL ALLOW TEMPERATURES TO DROP OFF FAIRLY
QUICK AFTER DARK AND IT`S LIKELY WE`LL SEE READINGS DROP INTO THE
UPPER TEENS IN SOME OF THE COLDER VALLEY SPOTS IN NORTHERN KLAMATH
AND NORTHWEST LAKE COUNTY. ELSEWHERE TEMPERATURES WILL DIP INTO THE
MID 20S TO MID 30S. THUS THE FREEZE WARNING AND FROST ADVISORIES
REMAIN IN EFFECT.

THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE OVERALL PICTURE FOR
THE NEXT 5-7 DAYS. AN UPPER RIDGE WILL BUILD WEST OF THE FORECAST
AREA WEDNESDAY THEN MIGRATING EAST OVER THE AREA THURSDAY AND
REMAINING THERE THROUGH EARLY NEXT WEEK. THIS WILL KEEP US DRY
WITH TEMPERATURES GRADUALLY WARNING UP EACH DAY AND WERE LIKELY TO
BE WELL ABOVE NORMAL STARTING THURSDAY AND LASTING INTO EARLY NEXT
WEEK. IT`S POSSIBLE WE COULD GET CLOSE TO 90 IN PARTS OF THE ROGUE
VALLEY FRIDAY INTO NEXT WEEKEND. IT`S STILL GOING TO BE COLD AT
NIGHT, ESPECIALLY EAST OF THE CASCADES AND MODELS SUGGEST
TEMPERATURES WILL END UP BELOW FREEZING AGAIN WEDNESDAY NIGHT INTO
THURSDAY MORNING. THEREFORE HAVE ISSUED A FREEZE WATCH. AFTER
THURSDAY MORNING, NIGHTTIME TEMPERATURES WILL GRADUALLY END UP
HIGHER, BUT WE COULD STILL SEE THEM DROP INTO THE LOWER TO MID 30S
IN THE VALLEY LOCATIONS IN NORTHERN KLAMATH, LAKE AND JUST EAST OF
MOUNT SHASTA.

AT THE SURFACE A THERMAL TROUGH WILL DEVELOP WITH INCREASING
OFFSHORE FLOW. THIS WILL RESULT IN MILDER TEMPERATURES OVER THE MID
SLOPES AND RIDGES. MEANWHILE AN INVERSION IS EXPECTED AND THIS WILL
RESULT IN COOLER TEMPERATURES IN THE VALLEYS. -PETRUCELLI


&&

.AVIATION...CLOUDS ARE DIMINISHING ACROSS THE FORECAST AREA AS A
DRIER AIR MASS MOVES IN. VERY LOCALIZED COASTAL MVFR CEILINGS AND
INLAND MOUNTAIN OBSCURATION ARE POSSIBLE THIS EVENING...BUT SHOULD
CLEAR OUT TONIGHT. WITH MOSTLY CLEAR SKIES EARLY TONIGHT AND
LINGERING MOISTURE AT THE SURFACE...A PERIOD OF IFR CONDITIONS IS
EXPECTED AT NORTH BEND AND IN ROSEBURG. CONFIDENCE IS HIGHER THAT
ROSEBURG WILL BECOME IFR TONIGHT...AND NOT AS CONFIDENT WITH
REDUCED VISIBILITIES AT NORTH BEND. THESE CONDITIONS SHOULD CLEAR
OUT WEDNESDAY MORNING...YIELDING VFR CONDITIONS EVERYWHERE
WEDNESDAY AFTERNOON. /SK


&&

.MARINE...UPDATED 3 PM PDT TUE 30 SEP 2014...OFFSHORE HIGH
PRESSURE BUILDING INTO THE COASTAL WATERS WILL CAUSE NORTH WINDS
AND WIND WAVE DOMINATED SEAS TO INCREASE THROUGH WEDNESDAY.
HAZARDOUS SEAS ARE EXPECTED SOUTH OF CAPE BLANCO THROUGH THURSDAY
MORNING WITH GALE FORCE WINDS POSSIBLE WEDNESDAY AFTERNOON AND
EVENING.
GUSTY SMALL CRAFT ADVISORY LEVEL NORTH WINDS WILL CONTINUE FOR
MUCH OF THE WATERS THROUGH WEDNESDAY THEN PUSH ABOUT 10NM
OFFSHORE WEDNESDAY NIGHT. WINDS AND SEAS WILL TREND LOWER THURSDAY
INTO FRIDAY AS HIGH PRESSURE WEAKENS AND A COLD FRONT PASSES TO
THE NORTH. SEAS WILL INCREASE AGAIN DUE TO A BUILDING WESTERLY
SWELL FRIDAY NIGHT. ON THE WEEKEND, STEEP SEAS AND GUSTY NORTH
WINDS ARE POSSIBLE ONCE MORE WITH THE STRONGEST WINDS IN THE
WATERS SOUTH OF CAPE BLANCO AS HIGH PRESSURE BUILDS OFFSHORE.


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FROST ADVISORY FROM 1 AM TO 8 AM PDT WEDNESDAY FOR ORZ029>031.
     FREEZE WARNING FROM 1 AM TO 8 AM PDT WEDNESDAY FOR ORZ029>031.
     FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING
     FOR ORZ029>031.

CA...FROST ADVISORY FROM 1 AM TO 8 AM PDT WEDNESDAY FOR
     CAZ081-082-084-085.
     FREEZE WARNING FROM 1 AM TO 8 AM PDT WEDNESDAY FOR
     CAZ082-084-085.
     FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING
     FOR CAZ082-084-085.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM
WEDNESDAY
     TO 11 PM PDT THURSDAY FOR PZZ350-370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 5 AM WEDNESDAY TO
     11 PM PDT THURSDAY FOR PZZ350-370.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT WEDNESDAY FOR
     PZZ356.
     HAZARDOUS SEAS WARNING FROM 5 AM WEDNESDAY TO 11 AM PDT
THURSDAY
     FOR PZZ356.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT
THURSDAY
     FOR PZZ356-376.
     GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING
     FOR PZZ376.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THURSDAY FOR
     PZZ376.
     HAZARDOUS SEAS WARNING UNTIL 11 AM PDT THURSDAY FOR PZZ376.

$$










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