National Weather Service Weather Forecast Office

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

000
FXUS66 KMFR 030401
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
801 PM PST MON MAR 2 2015

.DISCUSSION...NO UPDATES THIS EVENING. A SHORTWAVE UPPER TROUGH IS
MOVING THROUGH OUR AREA RIGHT NOW. THERE MAY BE A SPRINKLE OR
FLURRY LEFT IN THE WARNERS, BUT FOR THE MOST PART THIS IS NO
LONGER PRODUCING ANYTHING BUT CLOUDS. EVEN THE CLOUDS ARE
BEGINNING TO THIN OUT FROM THE NORTH, AND MODELS INDICATE THIS
WILL CONTINUE THROUGH THE NIGHT WITH PARTLY CLOUDY SKIES BY
MORNING. THE EAST SIDE WILL LIKELY HOLD ONTO CLOUDS LONGER THAN
ANYWHERE ELSE, BUT EVEN THERE IT SHOULD START TO CLEAR OUT BY
MORNING. THERE MAY BE SOME WEST SIDE VALLEY FOG, BUT IT`S GOING
TO BE A WHILE UNTIL THAT FORMS, IF ANY FORMS AT ALL. ALL OF THIS
IS WELL COVERED IN THE GOING FORECAST. -WRIGHT

&&

.AVIATION...FOR THE 03/00Z TAF CYCLE... A MARINE LAYER IS PRESENT
OVER THE COOS AND DOUGLAS COAST INLAND TO THE UMPQUA. THIS IS
BRINGING AREAS OF MOUNTAIN OBSCURATIONS AND LOCAL MVFR CIGS. EXPECT
GRADUAL CLEARING IN THE EVENING...ALTHOUGH SOME LOW TO MID CLOUDS
MAY LINGER WEST OF THE CASCADES INTO TONIGHT. THEN EARLY TUESDAY
MORNING EXPECT AREAS OF IFR CIGS AND VISIBILITIES TO DEVELOP IN THE
UMPQUA BASIN AFTER 12Z, INCLUDING AT KRBG. ELSEWHERE EXPECT MAINLY
VFR CONDITIONS TODAY THROUGH TUESDAY MORNING, ALTHOUGH LOCAL
IFR/MVFR CIGS ARE POSSIBLE LATE TONIGHT AND EARLY TUESDAY MORNING
WEST OF THE CASCADES. MND/CC

&&

.MARINE...UPDATED 3 PM PST, MONDAY, 2 MAR, 2015...A LOW DEPARTING TO
THE SOUTH THIS EVENING WILL LEAVE BEHIND MODERATE NORTH WINDS WITH
STEEP SEAS DUE TO A MIX OF NORTHWEST SWELL AND WIND SEAS. SEAS WILL
SUBSIDE SOME BY TUESDAY MORNING AS WINDS DIMINISH BRIEFLY BUT SWELL
REMAINS. SEAS WILL BECOME WIND DRIVEN BY TUESDAY AFTERNOON AS NORTH
WINDS INCREASE DUE TO A DEVELOPING THERMAL TROUGH AND HIGH PRESSURE
OFFSHORE. NORTH WINDS WILL WEAKEN LATE IN THE WEAK AS THE SURFACE
HIGH PRESSURE SHIFTS EASTWARD. MND

&&

PREV DISCUSSION... /ISSUED 244 PM PST MON MAR 2 2015/

SHORT TERM...THIS AFTERNOON THROUGH THURSDAY NIGHT...
A SHORTWAVE TROUGH OF LOW PRESSURE CONTINUES TO SHEAR APART AS IT
MOVES ACROSS THE AREA UNDER A GENERAL NORTH TO SOUTH ORIENTED JET
STREAM FLOW. THIS HAS LEFT SIGNIFICANT CLOUDINESS FROM GOLD BEACH
AND THE UMPQUA DIVIDE NORTHWARD ACROSS MAINLY WESTERN DOUGLAS AND
COOS COUNTIES AT THE LOWER LEVELS. THE MID AND UPPER LEVEL TROUGH
IS CAUSING SOME MOSTLY CLOUDY CONDITIONS AND LIGHT SNOW
SHOWER/FLURRY ACTIVITY ACROSS SOME OF THE HIGH TERRAIN FROM ABOUT
THE TRINITY ALPS EAST-NORTHEASTWARD INTO LAKE AND MODOC COUNTIES.
THIS AFTERNOON THROUGH THIS EVENING THESE TROUGH AND CLOUD
FEATURES WILL TRANSLATE SOUTHEASTWARD. COUPLED WITH SOME DAYTIME
SURFACE HEATING AND 700MB TEMPERATURES IN THE DENDRITIC GROWTH
ZONE, WE COULD WRING OUT SOME SNOW FLURRIES OR BRIEF AND LIGHT
SNOW SHOWERS ACROSS THE HIGH TERRAIN FROM THE CASCADES EASTWARD,
BUT AMOUNTS WILL BE A HALF INCH OR LESS.

TONIGHT THROUGH TUESDAY MORNING SCATTERED CLOUDINESS AND NEAR
FREEZING DEWPOINTS MEANS THERE WILL NOT BE MUCH IN THE WAY OF FOG
ON TUESDAY MORNING, EXCEPT ACROSS MOSTLY THE USUALLY FOGGIER
VALLEYS OF JOSEPHINE AND DOUGLAS COUNTIES. TEMPERATURES TONIGHT
WILL BE FROSTY, BUT NOT AS COLD AS WERE OBSERVED SUNDAY MORNING.

TUESDAY THROUGH THURSDAY NIGHT HIGH PRESSURE WILL BUILD EASTWARD
FROM THE EASTERN PACIFIC, REPLACING THE TROUGH THAT HAS BEEN
GIVING US SOMEWHAT WINTRY WEATHER OVER ABOUT THE LAST WEEK.

WE EXPECT WEDNESDAY MORNING TO BE THE COLDEST MORNING OF THIS WEEK
AHEAD FOR MANY VALLEY AREAS DUE TO OPTIMAL CONDITIONS FOR
RADIATIONAL COOLING TUESDAY NIGHT. TEMPERATURES ACROSS THE ROGUE
VALLEY WESTWARD IN OREGON TO THE COAST WILL MOSTLY BE WARMER THAN
WERE OBSERVED SUNDAY MORNING, WHILE IT SHOULD BE 5-10 DEGREES
COLDER IN PORTIONS OF THE SHASTA VALLEY. LOWS IN THE SHASTA VALLEY
LOOK TO BE 23-27F AND 26-32F IN THE ROGUE VALLEY ON WEDNESDAY
MORNING.

IN SHORT, WHILE MORNING LOWS WILL BE CLOSE TO NORMAL FOR THE
SHORT TERM PERIOD, HIGHS WILL WARM TO 5 TO 10 DEGREES ABOVE
CALENDER DAY NORMALS FOR WEDNESDAY AND THURSDAY. BTL

LONG TERM...FRIDAY THROUGH MONDAY...
MODELS ARE IN GOOD AGREEMENT THAT AN UPPER LEVEL HIGH PRESSURE
RIDGE WILL REMAIN OVER THE REGION THROUGH SUNDAY. THIS WILL BRING
ABOVE NORMAL HIGH TEMPERATURES AND DRY WEATHER. EXPECT WARMEST
TEMPERATURES TO OCCUR SATURDAY AND SUNDAY WITH HIGH TEMPERATURES
FORECAST IN THE UPPER 60S TO LOW 70S FOR INLAND VALLEYS WEST OF
THE CASCADES AND INTO THE 60S FOR EAST SIDE VALLEYS.

EARLY NEXT WEEK...EXPECT THE PATTERN TO SHIFT TO A WETTER AND COOL
MONDAY INTO TUESDAY. THERE IS SIGNIFICANT VARIABILITY IN THE
OPERATIONS GFS, ECMWF, AND GFS ENSEMBLE SOLUTIONS CONCERNING THE
TIMING AND TRACK OF THE TROUGH FORECAST TO MOVE INTO THE PACNW
MONDAY AND TUESDAY. SOLUTIONS VARY WITH THE UPPER TROUGH MOVING NEAR
THE PACNW COAST AND BRINGING A FRONT INTO THE AREA AS EARLY AS
MONDAY OR LATER TOWARDS TUESDAY NIGHT. HAVE GONE WITH A BLEND OF
SOLUTIONS AND HAVE A  SLIGHT CHANCE FOR PRECIPITATION ON MONDAY WEST
OF THE CASCADES THEN A CHANCE FOR PRECIPITATION WEST OF THE CASCADES
MONDAY NIGHT. /CC

&&

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

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR
     PZZ356-370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST THIS
     EVENING FOR PZZ350-356.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 1 PM TO 10 PM PST
     TUESDAY FOR PZZ350-356.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST TUESDAY
     FOR PZZ370-376.
     HAZARDOUS SEAS WARNING UNTIL 10 PM PST THIS EVENING FOR
     PZZ370-376.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST TUESDAY FOR
     PZZ376.
     SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM TO 10 PM PST TUESDAY
     FOR PZZ376.

$$