National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS66 KMFR 221005
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
305 AM PDT WED MAY 22 2013

.DISCUSSION...THE UPPER LOW THAT BROUGHT MUCH COOLER
TEMPERATURES...RAIN AND MOUNTAIN SNOW SHOWERS INCLUDING SOME
ACCUMULATING SNOW NEAR CRATER LAKE AND DIAMOND LAKE YESTERDAY WILL
LINGER OVER THE FORECAST AREA FOR THE NEXT COUPLE OF DAYS. THE UPPER
LOW WILL WEAKEN AND MOVE NORTHEAST FRIDAY AND SATURDAY.

PLENTY OF COLD AIR ALOFT IS MOVING OVERHEAD AS EVIDENT BY THE
SATELLITE IMAGE WHICH SHOWS PLENTY OF CUMULUS CLOUDS OVER THE OCEAN
AND ARE MOVING SOUTHEAST INTO SOUTHWEST OREGON. OF NOTE IS SOME
ENHANCEMENT NORTHWEST OF NORTH BEND...SO WE CAN EXPECT SHOWERS TO
INCREASE OVER THE NORTHWEST PART OF THE FORECAST AREA EARLY THIS
MORNING. SNOW LEVELS START OUT AROUND 2800 FEET EARLY THIS MORNING
AND COULD BRIEFLY DROP TO AROUND 2500 FEET IN HEAVIER SHOWERS.
HOWEVER DUE TO WARM ROAD AND GROUND TEMPERATURES I`M EXPECTING WET
SNOW SHOWERS TO MELT. THE EXCEPTION WILL BE AROUND DIAMOND AND
CRATER LAKE AND LAKE OF THE WOODS WHERE A TRACE TO AN INCH OF SLUSHY
SNOW COULD ACCUMULATE PRIOR TO 8 AM PDT. ANYTHING AFTER THAT SHOULD
MELT WITH SNOW LEVELS EXPECTED TO RISE BETWEEN 4000 AND 4500 FEET IN
THE AFTERNOON.

THE UPPER LOW REMAINS OVERHEAD TODAY WITH MULTIPLE SHORTWAVE
ROTATING AROUND IT ALONG WITH COLD AIR ALOFT. THEREFORE WE CAN
EXPECT ALMOST A REPEAT OF YESTERDAY WHERE SHOWERS WILL TEND TO
INCREASE FROM LATE MORNING THROUGH THE AFTERNOON. SOME OF THE
SHOWERS WILL BRING LOCALLY GUSTY WINDS AND SMALL HAIL FROM ABOUT MID
AFTERNOON INTO EARLY THIS EVENING.

SHOWERS WILL DECREASE SOME WEDNESDAY NIGHT...BUT DO NOT EXPECT MUCH
CLEARING TO TAKE PLACE WEST OF THE CASCADES AND TEMPERATURES WILL
REMAIN ABOVE FREEZING. IT WILL BE A CLOSE CALL IN THE KLAMATH BASIN.
THERE IS A CHANCE FOR LESS CLOUD COVER THERE AND ANY CLEARING WILL
ALLOW TEMPERATURES TO DROP QUICKLY. SO WE`LL PLAY IT SAFE AND ISSUE
A FREEZE WATCH FOR LATE TONIGHT/EARLY THURSDAY MORNING.

THE UPPER LOW LINGERS OVER THE AREA THURSDAY WITH SHOWER ACTIVITY AT
A MINIMUM IN THE MORNING THEN INCREASING AGAIN IN THE AFTERNOON. THE
NAM AND GFS SHOW A STRONGER SHORTWAVE SWINGING INTO SOUTHERN OREGON
IN THE AFTERNOON. THIS ALONG WITH INCREASING DAYTIME HEATING COULD
BE ENOUGH TO GENERATE ISOLATED THUNDERSTORMS EAST OF THE CASCADES
LATE IN THE AFTERNOON AND EARLY EVENING.

ANOTHER SHORTWAVE IS EXPECTED TO SWING INTO WESTERN OREGON FRIDAY
MORNING...THEN MOVE NORTHEAST FRIDAY AFTERNOON. SO WE CAN EXPECT
ANOTHER ROUND OF SHOWERS WITH A SLIGHT CHANCE OF ISOLATED STORMS
EAST OF THE CASCADES FRIDAY AFTERNOON. -PETRUCELLI


&&

.AVIATION...

BASED ON THE 22/06Z TAF CYCLE.

VFR CONDITIONS ARE EXPECTED TO PREVAIL TODAY. HOWEVER TEMPORARY MVFR
CONDITIONS WITH PARTIAL MOUNTAIN OBSCURATIONS AND REDUCED
VISIBILITIES ARE POSSIBLE NEAR AND WITHIN SHOWERS WITH LOCALLY
GUSTY WINDS.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
     ORZ029.
     FREEZE WARNING UNTIL 9 AM PDT THIS MORNING FOR ORZ029.

CA...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
     CAZ084.
     FREEZE WARNING UNTIL 9 AM PDT THIS MORNING FOR CAZ084.
     FREEZE WARNING UNTIL 9 AM PDT THIS MORNING FOR CAZ081.

PACIFIC COASTAL WATERS...HAZARDOUS SEAS WARNING UNTIL 5 PM PDT THIS
     AFTERNOON FOR PZZ350-356.
     HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR
     PZZ370-376.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 PM PDT THIS AFTERNOON FOR
     PZZ370.

$$