Area Forecast Discussion
Issued by NWS Medford, 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 KMFR 282308
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
300 PM PST FRI NOV 28 2014

.DISCUSSION...SHORT TERM. MODELS ARE COMING MORE IN LINE THAN
YESTERDAY WITH THE GFS AND THE ECMWF SHOWING CLOSE SOLUTIONS
THROUGH TUESDAY MORNING. THE HEAVIER BAND OF RAIN HAS MADE ITS WAY
INTO MODOC COUNTY WITH THE AXIS OF THE +100 KT JET. ANOTHER
STRONGER JET IS BEHIND THIS AND IS BRINGING ANOTHER ROUND OF
SHOWERS INTO THE WET SIDE AT THIS TIME. THESE SHOWERS WILL
CONTINUE AS THE JET AXIS SLOWLY MIGRATES THROUGH THE REGION
OVERNIGHT. IN THE SOUTHERLY WARM CONVEYOR FLOW SNOW LEVELS REMAIN
HIGH AND ABOVE PASS LEVELS...BUT WITH STRONGER SHOWERS SNOW LEVELS
MAY DROP BRIEFLY TO THE HIGHER PASS LEVELS. HOWEVER...WITH THE
GENERALLY WARM ROAD TEMPS...ANY SNOW THAT FALLS SHOULD MELT
RELATIVELY QUICKLY. A COOLER AIR MASS MOVES IN BEHIND THE FRONT AND
LIGHT SNOW AMOUNTS ARE POSSIBLE ON THE LOWER PASSES TOMORROW
MORNING. THE UPPER LOW WILL BE WELL OFFSHORE WITH CONVERGENCE
SETTING UP ALONG STATIONARY FRONT THAT SITS ROUGHLY ALONG THE CA/OR
STATE LINE THROUGH SUNDAY. THE UPPER LOW THEN MAKES ITS WAY BACK
INTO THE REGION BEFORE OPENING...BRINGING THE PRECIP BACK NORTH AS
THE FRONT IS NUDGED BACK NORTHWARD MONDAY INTO TUESDAY.

.LONG TERM...TUESDAY THROUGH FRIDAY. A CLOSED UPPER LOW IS FORECAST
TO WEAKEN AS IT APPROACHES THE CENTRAL CALIFORNIA COAST ON TUESDAY.
THE UPPER LOW WILL WEAKEN AND BECOME AN OPEN WAVE AS IT HEADS
NORTHEAST INTO NORTHERN CALIFORNIA TUESDAY NIGHT INTO WEDNESDAY.

THE GFS AND ECMWF SOLUTIONS DIVERGE BEHIND THIS SYSTEM LATE
WEDNESDAY THROUGH FRIDAY BUT NEITHER MODEL SHOWS A SIGNIFICANT STORM
THURSDAY AND FRIDAY. THE GFS SHOWS A COUPLE OF WEAK UPPER TROUGHS
PASSING THROUGH THE REGION WHILE THE ECMWF SHOWS A RIDGE BUILDING
WITH A STRONGER UPPER TROUGH WELL OFFSHORE.

HEAVIER PRECIPITATION WOULD BE FOCUSED MORE ACROSS NORTHERN
CALIFORNIA TUESDAY INTO WEDNESDAY WITH THE APPROACH OF THE LOW. SNOW
LEVELS WOULD LIKELY BE ABOVE I-5 PASS LEVELS DURING THE HEAVIEST
PRECIPITATION. THEN THE PATTERN MAY BE A MOIST ONSHORE FLOW WITH A
LOT OF CLOUD COVER AND LIGHT PRECIPITATION AT TIMES. TEMPERATURES
WILL PROBABLY BE ABOVE NORMAL FOR EARLY DECEMBER.
SANDLER


&&

.AVIATION...BASED ON THE 28/18Z TAF CYCLE...A COLD FRONT WILL MOVE
ACROSS THE WEST SIDE TONIGHT AND THEN BECOME NEARLY STATIONARY
ACROSS NORTHERN CALIFORNIA ON SATURDAY. RAINFALL WILL INCREASE NEAR
THE FRONT WITH MVFR CIGS AND/OR VISIBILITIES RETURNING. BY SATURDAY
AFTERNOON THE BAND OF PRECIPITATION WILL STRETCH FROM AROUND KMHS TO
KLKV. THE MOUNTAINS WILL SEE SHSN AS COLDER AIR MOVES IN BEHIND THE
FRONT.
SANDLER

&&

.MARINE...UPDATED 500 AM PST FRI NOV 28 2014...ISOLATED
THUNDERSTORMS ARE EXPECTED THROUGH EARLY THIS EVENING. SOUTH WINDS
AND WIND WAVES WILL PEAK THIS MORNING AHEAD OF AN INCOMING FRONT
WITH HIGH END SMALL CRAFT WINDS AND GALE GUSTS EXPECTED IN THE
COASTAL WATERS. SEAS WILL BECOME CHAOTIC BUILDING TO A VERY STEEP TO
STEEP 13 TO 16 FEET. A COLD FRONT WILL PUSH DOWN FROM THE NORTH LATE
THIS AFTERNOON AND TONIGHT. SO SOUTHERLY WINDS WILL TRANSITION TO
NORTHERLY TONIGHT WITH THE STRONGEST WINDS IN THE OUTER PORTION OF
THE WATERS. SEAS ARE LIKELY TO DIMINISH TONIGHT INTO EARLY NEXT
WEEK. WITH A LONG NORTHERLY FETCH, NORTH TO NORTHWEST WIND WAVES AT
8 SECONDS ARE LIKELY TO MIX WITH A DOMINANT FRESH SWELL AT 10
SECONDS WHILE SMALLER NORTHWEST AND SOUTHWEST SWELL TRAINS PERSIST.
THE PATTERN WILL REMAIN ACTIVE THROUGH NEXT WEEK. /DW


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 10 PM PST THIS EVENING FOR
     ORZ030-031-624-625.

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PST THIS EVENING FOR
     PZZ350-356-370-376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SATURDAY
     FOR PZZ350-356.
     SMALL CRAFT ADVISORY FOR WINDS FROM 7 PM SATURDAY TO 10 AM PST
     SUNDAY FOR PZZ370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
     FOR PZZ370-376.
     SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM SATURDAY TO 10 AM PST
     SUNDAY FOR PZZ376.

$$

SBN/SBN/SBN


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