Storm Watch 1, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
244 PM PST MON FEB 10 2014

.DISCUSSION...A WEAK FRONT WILL MOVE THROUGH THE AREA THIS EVENING
BRINGING LIGHT PRECIPITATION MAINLY ALONG THE COAST
RANGE...NORTHWEST DOUGLAS COUNTY AND NORTHERN CASCADES. NORTHERN CAL
AND MUCH OF THE EASTSIDE SHOULD REMAIN DRY WITH MIXED CLOUDS AND
SUN. THE FRONT WILL GET HUNG UP OVER THE NORTHERN PART OF THE
FORECAST AREA TONIGHT AND REMAIN NEARLY STATIONARY THROUGH TUESDAY
MORNING. THEREFORE HAVE KEPT A SLIGHT CHANCE TO CHANCE POPS THERE.
ELSEWHERE I'M FAIRLY CONFIDENT WE'LL REMAIN DRY.

THE FLOODGATES OPEN UP TUESDAY NIGHT AND REMAIN OPEN THROUGH
WEDNESDAY NIGHT. THE MODELS REMAIN IN FAIRLY GOOD AGREEMENT BRINGING
MODERATE TO HEAVY RAIN ALONG THE COAST...COASTAL MOUNTAINS AND
CASCADES WITH A LONG FETCH OF TROPICAL CONNECTION OUT TO HAWAII.
MODELS SUGGEST STORM TOTALS DURING THIS TIME PERIOD ARE AS
FOLLOWS: 3-5 INCHES ALONG THE COAST AND WESTERN SISKIYOU COUNTY
WITH UP TO 7 INCHES OVER THE COASTAL MOUNTAINS. 3-5 INCHES IN THE
CASCADES AND 1-2 INCHES IN PORTIONS OF DOUGLAS COUNTY. A PERSISTENT
SOUTHWEST FLOW IS EXPECTED WHICH SHOULD LIMIT THE AMOUNT OF
PRECIPITATION IN PARTS OF THE ROGUE AND SHASTA VALLEYS, BUT BOTH
WILL RECEIVE BENEFICIAL RAIN WITH UP TO AN INCH POSSIBLE. SNOW
LEVELS REMAIN HIGH AND WILL START OUT AROUND 6000 FEET, THEN
INCREASE TO AROUND 8000-8500 FEET WEDNESDAY. THE ONE PIECE OF GOOD
NEWS IS WE NEED THE RAIN AND WHILE WE'LL SEE RAPID RISES TO STREAMS
AND SMALL CREEKS, MAIN STEM RIVERS ARE NOT EXPECTED TO REACH FLOOD
STAGE THROUGH WED NIGHT. WHAT THAT SAID, I DID ISSUE AN ESF
HIGHLIGHTING THE POTENTIAL FOR FLOODING, BUT THE CONCERN FOR
FLOODING MAY NOT OCCUR UNTIL THIS WEEKEND. WE'LL CONTINUE TO MONITOR
THIS CLOSELY IN THE DAY TO COME.

THE MODELS SUGGEST WE COULD CATCH A BRIEF BREAK FROM THE MODERATE
TO HEAVY PRECIPITATION ON THURSDAY, THEN ANOTHER STORM WILL BRING
THE NEXT ROUND OF HEAVY PRECIPITATION THURSDAY NIGHT. KEEP IN MIND
THE DETAILS ON THE TIMING WILL LIKELY VARY FROM DAY TO DAY.

THE NEXT IMPACT WILL BE THE POTENTIAL FOR MODERATE TO STRONG WINDS
ALONG COAST...NORTH OF CAPE BLANCO AND HEADLANDS AND HIGHER TERRAIN
EAST OF THE CASCADES. THE GFS SHOWS 925 MB WINDS PUSHING 60 KTS
MAINLY NORTH OF CAPE BLANCO TUESDAY NIGHT INTO EARLY WEDNESDAY
MORNING MORNING WITH A SLIGHT SOUTHWEST COMPONENT. IF THIS REMAINS
CONSISTENT, THEN WE COULD APPROACH HIGH WIND CRITERIA. MEANWHILE
700MB WINDS BETWEEN 50-60 KTS FROM THE WEST ARE EXPECTED WHICH WILL
RESULT IN SOME OF THE HIGHER TERRAIN AND HIGHWAY 31 EAST OF SUMMER
ALSO REACHING HIGH WIND CRITERIA. THUS HAVE DECIDED TO ISSUE A HIGH
WIND WATCH FOR THE ABOVE LOCATIONS. DETAILS CAN BE FOUND AT NPWMFR.
-PETRUCELLI

.LONG TERM...FRIDAY THROUGH MONDAY.

AN ACTIVE AND WET PATTERN IS EXPECTED THROUGH THE EXTENDED PERIOD
WITH SEVERAL FRONTS MOVING INTO THE AREA THURSDAY NIGHT THROUGH
MONDAY.

THE 12Z MODELS ARE IN AGREEMENT THAT A FRONT WILL MOVE INLAND
THURSDAY NIGHT INTO FRIDAY THEN STALL ACROSS THE AREA THROUGH FRIDAY
NIGHT. HIGH MOISTURE CONTENT IS ASSOCIATED WITH THIS FRONT ON FRIDAY
AS MODELS ARE CONTINUING TO SHOW A PERSISTENT TROPICAL MOISTURE
CONNECTION. THE GFS AND GEFS SHOW INTEGRATED MOISTURE TRANSPORT
VALUES OF 600 OR GREATER IN A MOISTURE STREAM EXTENDING
FROM NEAR THE HAWAIIAN ISLANDS TO THE SOUTHERN OREGON COAST. AS A
RESULT, EXPECT MODERATE TO HEAVY RAINFALL OVER THE AREA WITH THIS
FRONT, ESPECIALLY FOR AREAS FROM THE COAST TO THE CASCADES. THE
STALLED FRONT MAY PUSH SLIGHTLY SOUTH FRIDAY NIGHT AS DEPICTED BY
THE ECMWF MODEL AND LINGER OVER NORTHERN CALIFORNIA.  HOWEVER
STILL EXPECT LIGHT TO MODERATE RAIN POSSIBLE ACROSS SOUTHERN
OREGON.

THEN ON SATURDAY, MODEL SOLUTIONS INDICATE THAT STRONG FRONT WILL
IMPACT THE AREA. THE GFS, GEFS AND ECMWF ALL SHOW A LOW PRESSURE
CENTER MOVING TOWARDS THE PACNW COAST EARLY SATURDAY...THEN
NORTHEAST INTO BRITISH COLUMBIA SATURDAY EVENING. THIS LOW IS
EXPECTED TO BRING A FRONT INLAND OVER THE AREA SATURDAY INTO
SATURDAY EVENING. WHERE THIS FRONT MEETS THE STATIONARY FRONT
BOUNDARY OVER NORTHERN CALIFORNIA AND SOUTHERN OREGON EXPECT
INCREASED RAIN RATES WITH MODERATE TO HEAVY RAINFALL POSSIBLE.

HEAVY RAINFALL WITH THESE FRONTS AS WELL AS  FROM THE EARLY FRONT ON
TUESDAY, MAY BRING THE POTENTIAL FOR FLOODING, MAINLY  SMALL STREAM
FLOODING FOR AREAS NEAR THE COAST AND POSSIBLY INLAND SUCH AS IN THE
UMPQUA BASIN. MAINSTEM RIVERS CAN EXPECT TO SEE SIGNIFICANT RIVER
RISES BY SATURDAY, ESPECIALLY FOR RIVERS WEST OF THE CASCADES IN
OREGON. CURRENT HYDROLOGIC MODELS DO NOT INDICATE MAINSTEM RIVER
FLOODING. HOWEVER WE WILL BE MONITORING PRECIPITATION FORECASTS AS
WE GET CLOSER TO THIS EVENT. OF CONCERN WILL BE HOW LONG THE FRIDAY
FRONT LINGERS OVER THE AREA AND HOW HIGH THE RAIN RATES ARE WITH
EACH OF THESE SYSTEMS.

ALSO  THESE FRONTS FRIDAY AND SATURDAY WILL BRING THE POTENTIAL FOR
STRONG AND GUSTY WINDS TO THE AREA, MAINLY OVER THE MOUNTAINS AND
INTO THE SHASTA VALLEY AND SUMMER LAKE AREAS. ALSO LOCATIONS ALONG
THE COAST MAY SEE GUSTY WINDS AT TIMES THURSDAY NIGHT INTO EARLY
FRIDAY AND AGAIN SATURDAY.

THE FRONT ON SATURDAY IS NOT EXPECTED TO LINGER AND MODELS SHOW GOOD
AGREEMENT THAT IT WILL PUSH EAST OF THE AREA SATURDAY NIGHT INTO
SUNDAY MORNING. THIS WILL ALLOW COLDER AIR TO MOVE INTO THE AREA.
SNOW LEVELS WHICH ARE FORECAST GENERALLY ABOVE 6000 FEET FRIDAY AND
SATURDAY, ARE EXPECTED TO LOWER EARLY SUNDAY TO AROUND 3500 TO 5000
FEET. BEHIND THE FRONT EXPECT A BREAK IN THE ACTIVE PATTERN ON
SUNDAY. THEN ANOTHER FRONTAL SYSTEM IS FORECAST TO APPROACH FROM THE
NORTHWEST EARLY MONDAY AND MOVE INLAND DURING THE DAY. MODELS
INDICATE THAT THIS FRONT WILL BRING LESS PRECIPITATION THAN THE
PREVIOUS FRONTS AS IT IS LACKING THE TROPICAL MOISTURE CONNECTION.
MODELS INDICATE MAINLY LIGHT TO MODERATE PRECIPITATION FROM THE
CASCADES WEST. SNOW LEVELS ARE EXPECTED TO REMAIN AROUND 4000 TO
5000 FEET ON MONDAY. /CC

&&

.AVIATION...BASED ON THE 10/18Z TAF CYCLE.
AREAS OF SHOWERS WILL PERSIST THIS AFTERNOON INTO THIS EVENING ALONG
THE COAST AND INLAND INTO THE UMPQUA VALLEY AND PORTIONS OF THE
CASCADES. ALONG THE COAST...MVFR CIGS WITH LOCAL IFR CIGS ARE
EXPECTED TO CONTINUE THIS AFTERNOON INTO EARLY THIS EVENING. THEN
EXPECT IFR CIGS TO DEVELOP TONIGHT AND PERSIST INTO TUESDAY MORNING.
INLAND...VFR CONDITIONS WILL CONTINUE THIS AFTERNOON...WITH LOCAL
MVFR CIGS AND AREAS OF PARTIAL MOUNTAIN OBSCURATIONS WEST OF THE
CASCADES IN OREGON. EXPECT INCREASING MVFR CIGS TO DEVELOP WEST OF
THE CASCADES LATE THIS EVENING WITH INCREASING MOUNTAIN
OBSCURATIONS.  THEN LATE TONIGHT INTO TUESDAY MORNING AREAS OF IFR
CIGS AND IFR/MVFR VISIBILITIES WILL DEVELOP IN INLAND VALLEY
LOCATIONS, INCLUDING AT KRBG, KMFR AND KLMT. /CC

&&

.MARINE...
A WEAK FRONT IS MOVING ACROSS THE COASTAL WATERS TODAY. THEN STRONG
GALE FORCES WINDS AND VERY STEEP SEAS ARE FORECAST TO DEVELOP
TUESDAY NIGHT INTO WEDNESDAY MORNING AS A STRONG FRONT MOVES INTO
THE WATERS. ADDITIONAL STRONG FRONTS ARE EXPECTED THURSDAY THROUGH
SATURDAY. SEAS WILL LIKELY REMAIN HIGH AND VERY STEEP THROUGH AT
LEAST SUNDAY. ALSO ADDITIONAL PERIODS OF GALE FORCE WINDS ARE
POSSIBLE AS  FRONTS MOVE ACROSS THE WATERS AROUND THURSDAY NIGHT,
SATURDAY AND SUNDAY NIGHT. /CC

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM TUESDAY EVENING THROUGH LATE TUESDAY NIGHT
     FOR ORZ021.
     HIGH WIND WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
     MORNING FOR ORZ030-031.

CA...HIGH WIND WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
     MORNING FOR CAZ085.

PACIFIC COASTAL WATERS...NONE.