Hazardous Seas Warning 32, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
242 PM PDT SUN MAR 20 2016

.SHORT TERM...A FRONT OVER THE AREA TODAY WILL SHIFT EASTWARD THIS
EVENING AND TONIGHT WITH DECREASING SHOWERS OVER INLAND AREAS. A
COLD FRONT WILL THEN APPROACH LATE TONIGHT AND MOVE INLAND MONDAY
AND BRING ANOTHER ROUND OF WET AND WINDY WEATHER. BEHIND THIS
FRONT EXPECT A SHOWERY AND COOL PATTERN AS AN UPPER TROUGH MOVES
OVER THE REGION.

A FRONT IS CURRENTLY MOVING EAST OF THE CASCADES THIS AFTERNOON
AND BEHIND THE FRONT THIS EVENING, EXPECT MAINLY SCATTERED
SHOWERS, WITH THE BEST CHANCES FOR SHOWERS ALONG THE COAST AND
OVER THE MOUNTAINS. GUSTY SOUTH WINDS WILL CONTINUE THIS AFTERNOON
THEN LOWER DURING THE EVENING. AS THE FRONT SHIFTS EAST OF THE
AREA, SHOWERS WILL DECREASE OVERNIGHT FOR INLAND AREAS AND THEN
INCREASE IN THE EARLY MORNING HOURS ACROSS WESTERN AREAS AS A
COLD FRONT MOVES TOWARDS THE COAST. SNOW LEVELS WILL LOWER TO
AROUND 5000 TO 6000 FEET FROM THE CASCADES WEST THEN DOWN TO 4500
TO 5000 FEET TONIGHT OVER THE AREA.

ON MONDAY, THE COLD FRONT WILL MOVE INLAND DURING THE DAY AND
BRING LIGHT TO MODERATE RAIN AND MOUNTAIN SNOW. SNOW LEVELS ARE
EXPECTED NEAR 4500 TO 5000 FEET THROUGH THE DAY MONDAY WITH LIGHT
TO LOCALLY MODERATE SNOW ACCUMULATIONS EXPECTED ABOVE 5000 FEET.
HEAVIEST ACCUMULATIONS ARE EXPECTED IN THE CRATER LAKE AREA WHERE
AROUND 6 INCHES OF SNOW IS EXPECTED DURING THE DAY WITH A FEW
ADDITIONAL INCHES OF SNOW EXPECTED IN SHOWERS MONDAY NIGHT. COLD
AIR ALOFT AND INSTABILITY WILL BRING A SLIGHT RISK FOR
THUNDERSTORMS ON MONDAY, MAINLY FOR COASTAL AREAS AND FROM THE
CASCADES EASTWARD. SOUTH WINDS ARE EXPECTED TO INCREASE AGAIN ON
MONDAY AHEAD OF THE FRONT, WITH STRONGEST WINDS OVER THE MOUNTAINS
E AND INTO THE SHASTA VALLEY AND SUMMER LAKE AREAS. A WIND
ADVISORY IS IN EFFECT FOR THESE AREAS WITH WINDS EXPECTED TO GUST
TO AROUND 45 MPH.

BEHIND THE FRONT MONDAY EVENING AND NIGHT, EXPECT WIDESPREAD
SHOWERS AS MODELS CONTINUE TO SHOW THE UPPER TROUGH MOVING
INLAND. THIS WILL ALSO BRING A COLDER AIRMASS INTO THE AREA AND
SNOW LEVELS WILL LOWER TO 3000 TO 3500 FEET MONDAY NIGHT. A SLIGHT
RISK OF THUNDERSTORMS CONTINUES IN MONDAY NIGHT AS WELL, MAINLY
FOR THE COASTAL WATERS AND ALONG THE COAST.

THE COOL AND SHOWERY PATTERN CONTINUES THROUGH TUESDAY AFTERNOON
THEN MODELS SHOW GOOD AGREEMENT THAT SHOWERS WILL TAPER OFF
TUESDAY NIGHT AS THE UPPER TROUGH SHIFTS EASTWARD. LIGHT SNOW
ACCUMULATIONS ARE LIKELY MONDAY NIGHT THROUGH TUESDAY OVER THE
MOUNTAIN PASSES ABOVE 3000 FEET ELEVATION AND EXPECT LIGHT SNOW
EAST OF THE CASCADES WITH THESE SHOWERS. HIGHER PASSES IN THE
CASCADES ARE EXPECTED TO SEE 2 TO 5 INCHES OF SNOW MONDAY NIGHT
THROUGH TUESDAY MORNING WITH AROUND 2 INCHES AT SISKIYOU SUMMIT.

.LONG TERM...WEDNESDAY THROUGH SUNDAY NIGHT...THE LATEST EC AND GFS
AGREE ON UPPER RIDGING AND DRY WEATHER ON WEDNESDAY. TEMPERATURES
ARE EXPECTED TO BE NEAR NORMAL ON WEDNESDAY WITH MOSTLY HIGH CLOUDS.
A WEAK FRONT WILL MOVE THROUGH ON THURSDAY...WITH MOST OF THE
PRECIPITATION CONFINED TO THE CASCADES...UMPQUA BASIN...AND COAST.
TEMPERATURES SHOULD REMAIN NEAR NORMAL. DIFFERENCES BETWEEN THE EC
AND GFS BEGIN TO SHOW ON FRIDAY WITH THE EC DROPPING ENERGY FROM THE
NORTH...AROUND THE EASTERN EDGE OF THE RIDGE AND INTO THE FORECAST
AREA.  THE GFS SUGGESTS ENERGY RIDING OVER THE TOP OF THE
RIDGE...WITH MORE OF A NORTHWESTERLY FLOW...BRINGING MORE
APPRECIABLE PRECIPITATION BY FRIDAY NIGHT. IN EITHER CASE...IMPACTS
TO THE FORECAST AREA WILL BE MINIMAL WITH NEITHER SOLUTION SHOWING A
VIGOROUS STORM...AND ONLY LIGHT TO MODERATE PRECIPITATION.

ON SATURDAY THE AREA WILL REMAIN EAST OF A HIGH OVER THE PACIFIC,
WITH A WEAK FRONT PASSING THROUGH SUNDAY NIGHT INTO MONDAY. ANY
RAINFALL WILL BE PRIMARILY NORTH OF THE MFR CWA...BUT SOME SHOULD
EXTEND INTO THE AREA. THE MAIN QUESTION IS ON TIMING...THE GFS
BRINGS THE FRONT IN A BIT FASTER THAN THE EC...ENDED UP GOING WITH A
BLEND, BUT LEANING TOWARDS THE EC GIVEN STRONGER RUN TO RUN
CONSISTENCY. BEFORE THE FRONT, EXPECT DRY CONDITIONS AND WARMER THAN
NORMAL TEMPERATURES...CAUSING A THERMAL TROUGH TO DEVELOP WITH
ENHANCED NORTHERLY WINDS OVER THE WATERS.

&&

.AVIATION...FOR THE 20/18Z TAF CYCLE...A FRONTAL SYSTEM WILL
SPREAD AND MOUNTAIN OBSCURATION INLAND TODAY. MOSTLY VFR CONDITIONS
ARE BEING OBSERVED NOW...BUT OCCASIONAL LOWERING CEILINGS TO MVFR IS
POSSIBLE. RAIN AND MVFR CIGS/VIS TO THE COAST THIS MORNING. ENOUGH
INSTABILITY THIS AFTERNOON SUPPORTS THE CHANCE FOR THUNDERSTORMS
BEHIND THE FRONT. GUSTY SOUTH WINDS AND INCREASED CHANCES FOR
TURBULENCE ARE EXPECTED ALONG AND BEHIND THE FRONT...ESPECIALLY AT
THE COAST...EAST OF THE CASCADES AND OVER HIGH TERRAIN.
PRECIPITATION WILL TAPER TO SHOWERS AND WINDS SHOULD WEAKEN BY THIS
EVENING. THE NEXT FRONT WILL BRING ANOTHER PERIOD OF LOWERING
CEILINGS TO THE COAST MONDAY MORNING AND THEN INLAND...WITH ANOTHER
CHANCE FOR THUNDERSTORMS. SK

&&

.MARINE...UPDATED 315 AM PDT SUN 20 MAR 2016...A STRONG COLD FRONT
WILL BRING GALES AND STEEP WIND DRIVEN SEAS THIS MORNING. SEAS WILL
CONTINUE TO BUILD THIS AFTERNOON AND EVENING BEFORE ANOTHER BRIEF
PERIOD OF GALES WITH THE NEXT COLD FRONT LATE TONIGHT. HAZARDOUS
SEAS WILL BECOME DOMINATED BY A WEST SWELL AND REACH A PEAK ON
MONDAY NIGHT THEN REMAIN HIGH INTO EARLY WEDNESDAY. HIGH PRESSURE
WITH MODERATE SEAS WEDNESDAY IS LIKELY TO BE FOLLOWED BY A WEAK
FRONT WITH BUILDING SEAS BECOMING HIGH WEDNESDAY NIGHT INTO THURSDAY.
HIGH SEAS LOOK TO PERSIST INTO FRIDAY THEN BRIEFLY DIMINISH INTO
SATURDAY. -DW

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR ORZ030-031.
     WIND ADVISORY FROM 11 AM TO 5 PM PDT MONDAY FOR ORZ030-031.

CA...WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR CAZ085.
     WIND ADVISORY FROM 11 AM TO 5 PM PDT MONDAY FOR CAZ085.
     WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR CAZ081.
     WIND ADVISORY FROM 8 AM TO 2 PM PDT MONDAY FOR CAZ081.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 AM PDT WEDNESDAY FOR
     PZZ350-356-370-376.
     GALE WARNING UNTIL 2 PM PDT THIS AFTERNOON FOR
     PZZ350-356-370-376.
     HAZARDOUS SEAS WARNING UNTIL 11 AM PDT MONDAY FOR
     PZZ350-356-370-376.

CC/NSK