Flood in Oregon, March 14 to 16, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
841 PM PDT MON MAR 14 2016

.DISCUSSION...THE WEATHER PATTERN IS GRADUALLY QUIETING...WITH
SOME UPSLOPE SNOW SHOWERS CONTINUING TONIGHT IN UNSTABLE
CONDITIONS. WINTER WEATHER IMPACTS WILL WANE TONIGHT...AND A
WINTER WEATHER ADVISORY FOR THE CASCADES WILL EXPIRE THIS EVENING.

HEAVY PRECIPITATION OVER THE WEEKEND HAS RESULTED IN SWOLLEN
RIVERS...AND THE COQUILLE AT COQUILLE IS RIGHT AT MINOR FLOOD STAGE...SO
A FLOOD WARNING CONTINUES AT FLSMFR AT THAT LOCATION. OTHER RIVERS
THAT HAVE RISEN SIGNIFICANTLY ARE HIGHLIGHTED IN A HYDROLOGIC
OUTLOOK AT ESFMFR. ON THE WHOLE THOUGH...RIVERS ARE BEGINNING TO
RECEDE ACROSS THE AREA.

ATTENTION TURNS TO COLD OVERNIGHT TEMPERATURES AND POTENTIAL
IMPACTS TO AGRICULTURE. THE NEXT THREE NIGHTS HAVE THE POTENTIAL
FOR TEMPERATURES NEAR FREEZING...AND INTERESTED PARTIES SHOULD
TUNE IN CLOSELY TO THE FORECAST. TONIGHT REPRESENTS THE NIGHT WITH
THE COLDEST AIR MASS BUT CLOUDS WILL LIKELY AFFECT MUCH OF THE
AREA...ESPECIALLY ON THE WEST SLOPES OF ANY TERRAIN. STILL...CLEAR
SKY POTENTIAL FOR ANY AREA THAT DOES CLEAR OUT IS UPPER 20S NEAR
THE ROGUE VALLEY. OUR FORECAST REFLECTS THE EXPECTED CLOUD
COVER...AND IS IN THE LOW TO MID 30S AROUND THE ROGUE VALLEY THE
NEXT SEVERAL NIGHTS.

PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR MORE DETAILS AND A
LOOK AT THE EXTENDED.

&&

.AVIATION...FOR THE 15/00Z TAF CYCLE...LIGHT SHOWERS AND SNOW
SHOWERS WILL GRADUALLY DECREASE IN COVERAGE BUT LINGER THROUGH
TUESDAY WITH A MAJORITY OF THE ACTIVITY FROM COOS AND DOUGLAS
COUNTIES NORTHWARD...INCLUDING NORTH BEND AND ROSEBURG.
THE SHOWERS WILL ACCOMPANY AREAS OF MVFR CONDITIONS WITH MOUNTAIN
OBSCURATION. ELSEWHERE...MAINLY VFR CEILINGS ARE EXPECTED TO PERSIST
THROUGH TUESDAY WITH ISOLATED MVFR NEAR WEST FACING SLOPES. /DW

&&

.MARINE...UPDATED 500 PM PDT MON 14 MAR 2016...A STEEP WEST SWELL
WILL SUBSIDE BUT REMAIN HIGH THROUGH TUESDAY EVENING. A WEAK FRONT
WILL BRUSH PAST TUESDAY NIGHT THEN HIGH PRESSURE OFFSHORE AND A
THERMAL TROUGH ALONG THE COAST WILL LIKELY PRODUCE GUSTY NORTH TO
NORTHEAST WINDS WITH STEEP WIND WAVES WEDNESDAY THROUGH THURSDAY.
THESE WINDS WILL BE STRONGEST BEYOND 10NM FROM SHORE AND SOUTH OF
CAPE ARAGO. LIGHT TO MODERATE WINDS AND SEAS ARE EXPECTED TO FOLLOW
THURSDAY NIGHT INTO FRIDAY NIGHT. WEST SWELL IS LIKELY TO INCREASE
BUT REMAIN MODERATE AT THE END OF THE WEEK AHEAD OF A COUPLE OF
FRONTS OF WEAK TO MODERATE STRENGTH. /DW

&&

.PREV DISCUSSION... /ISSUED 311 PM PDT MON MAR 14 2016/

SHORT TERM...THROUGH THURSDAY NIGHT...
RAIN AND SNOW SHOWERS CONTINUE THIS AFTERNOON. ONE HOUR
PRECIPITATION RATES HAVE BEEN UNDER 0.10" AND 6 HOUR TOTALS UNDER
0.30" AT NEARLY ALL LOCATIONS. SNOTELS IN THE OREGON CASCADES
INDICATE ONLY 1 TO 3 INCHES OF SNOW HAS FALLEN SINCE SUNRISE,
THOUGH AN APPRECIABLE BATCH OF SHOWERS IS CURRENTLY MOVING
THROUGH THIS AFTERNOON. ALL IN ALL, I HAVE DIMINISHED THE AREA
UNDER WINTER HEADLINES, AS THE CURRENT WEATHER SYSTEM'S MORE
PRONOUNCED DYNAMICS ARE MOVING NORTHEASTWARD AND PRECIPITATION
RATES SHOULD CONTINUE TO DIMINISH FURTHER THIS EVENING.

REGARDING HYDROLOGY, THE COQUILLE RIVER AT COQUILLE IS HOVERING
JUST BELOW FLOOD STAGE AND IS EXPECTED TO NUDGE INTO MINOR FLOOD
STAGE DUE TO TIDAL INFLUENCES LATER TODAY INTO TONIGHT. THE ROGUE
AT AGNESS HAS PEAKED AT ACTION STAGE AND WILL RECEDE TONIGHT. THE
SPRAGUE RIVER AT BEATTY IS STILL RISING AND IS EXPECTED TO CREST
JUST ABOVE ACTION STAGE TOMORROW MORNING.

CURRENTLY, THE JET STREAM IS SHIFTING NORTHEASTWARD THROUGH OUR
AREA, WHICH, ALONG WITH AFTERNOON HEATING, WILL GIVE SHOWERS A BIT
OF A BOOST FROM MOUNT MCLOUGHLIN NORTHWARD INTO DOUGLAS COUNTY.
SUSPECT ADDITIONAL SNOW AMOUNTS WILL BE IN THE 1 TO 4 INCH RANGE
IN THE ADVISORY AREAS.

LATER TONIGHT THROUGH WEDNESDAY ADDITIONAL WEAK SHORT WAVE TROUGHS
WILL SKIRT THE AREA FROM THE WEST AS TEMPERATURES BEGIN TO
MODERATE. EXPECT THE USUAL WEST SIDE LINGERING LOW CLOUDS AND
FOG, ESPECIALLY IN THE MORNING HOURS, ALONG NORTH AND WEST FACING
SLOPES THROUGH MUCH OF THIS PERIOD. LIGHT PRECIPITATION WILL BE
POSSIBLE ON THE WEST SIDE AND SHOULD BE EXPECTED ALONG THE COAST
AND IN THE COAST RANGE AND ACROSS DOUGLAS COUNTY DURING THIS TIME
PERIOD.

WEDNESDAY NIGHT THROUGH FRIDAY MORNING WINDS WILL BE MOSTLY FROM
THE EAST AND NORTHEAST EACH NIGHT AND MORNING AS LIGHT TO MODERATE
OFFSHORE FLOW OCCURS. EXPECT THIS FLOW WILL NOT BE STRONG ENOUGH
TO OVERWHELM NORMAL AFTERNOON VALLEY-MOUNTAIN WINDS EXCEPT ON THE
RIDGES. THUS, EXPECT WE'LL HAVE OVERNIGHT AND MORNING INVERSIONS
THAT WILL BREAK IN MOST AREAS IN THE AFTERNOONS THANKS TO THE
STRONGER MARCH SUN AND SOMEWHAT LONGER DAYS. BTL

LONG TERM...FRIDAY THROUGH MONDAY...
THE 12Z GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING A WEAK FRONT
MOVING INTO THE UPPER RIDGE FRIDAY NIGHT INTO SATURDAY, WITH THE
UPPER RIDGE GRADUALLY SHIFTING EASTWARD. OVERALL, EXPECT THIS
FRONT TO MAINLY ONLY BRING A CHANCE OF LIGHT PRECIPITATION TO THE
COAST FRIDAY NIGHT WITH A SLIGHT CHANCE OF RAIN SHOWERS INLAND TO
NEAR THE CASCADES ON SATURDAY. THIS IS FOLLOWED BY AN UPPER TROUGH
MOVING TOWARDS THE PACNW COAST ON SUNDAY AND A FRONT MOVING INLAND
OVER THE AREA SUNDAY AND SUNDAY NIGHT. MODELS THEN SHOW ANOTHER
FRONT MOVING INTO THE AREA ON MONDAY. THESE FRONTS ARE FORECAST TO
BRING LIGHT TO MODERATE PRECIPITATION WITH THE BEST CHANCES FOR
PRECIPITATION FROM THE CASCADES WEST. SNOW LEVELS ARE EXPECTED TO
REMAIN FAIRLY HIGH, INITIALLY AROUND 7000 FEET OR HIGHER FRIDAY
NIGHT AND SATURDAY THEN LOWERING TO 5000 TO 6500 FEET SUNDAY NIGHT
AND MONDAY. /CC

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
     ORZ025-027-028.

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM PDT TUESDAY
     FOR PZZ350-356-370-376.

NSK/CC/DW