Spring Thaw Outlook - 20 March 2014 update!

HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS ND
935 AM CDT THU MAR 20 2014

...SPRING THAW PROGRESS FOR RED RIVER OF THE NORTH...

IN GENERAL... WARMER TEMPERATURES LATE LAST WEEK PRODUCED
WIDESPREAD WARMING AND/OR MELTING OF AREA SNOWPACK WITH SOME
LOCALIZED RUNOFF EVIDENT IN THE SOUTHERN RED RIVER BASIN. SOMEWHAT
COOLER TEMPERATURES FROM THE WEEKEND INTO THE MIDDLE OF THIS
WEEK HAVE SLOWED OR STALLED ANY MELT AND RUNOFF PROCESSES.

CURRENT STATUS OF BASIN SNOWPACK:

- HEADWATERS AND SOUTHERN THIRD OF RED RIVER VALLEY.
SNOW COVER IS LARGELY ABSENT OVER THE LANDSCAPE UPSTREAM /SOUTH/ OF
FARGO INTO THE TRI-STATE BORDER AREA AND LAKE TRAVERSE DRAINAGE.
DITCH NETWORKS AND SMALLER STREAMS ARE SHOWING INTERMITTENT STRETCHES
OF OPEN WATER FLOW... WITH DAYTIME THAW AND NIGHTTIME FREEZE
CONDITIONS STILL KEEPING SOME CULVERTS SLOW OR PLUGGED. SOME STREAMS
AND TRIBUTARIES DID SHOW A BRIEF RESPONSE TO WARMER TEMPERATURES
EARLY IN THE WEEK DUE TO LOCALIZED SNOWMELT RUNOFF BUT HAVE SINCE
DIMINISHED. THE LARGER TRIBUTARIES AND MAINSTEM RED RIVER ARE SHOWING
PATCHY OPEN WATER ALONG THE RIVER BANKS AND ARE SLOWLY GAINING WATER
FROM NEAR STREAM RUNOFF. OTHERWISE THESE SYSTEMS ARE NOT YET SHOWING
LARGE SCALE ICE BREAKUP OR OPEN FLOW.

- MIDDLE THIRD OF THE RED RIVER VALLEY.
PATCHY BUT SLIGHT SNOW COVER REMAINS OVER THE CENTRAL VALLEY BETWEEN
GRAND FORKS AND FARGO. MOST DITCHES AND SMALLER STREAMS ARE PARTIALLY
FILLED WITH SNOW AS ARE MOST SHELTER BELTS. FIELDS ARE GENERALLY 50
PERCENT OR GREATER SNOW FREE DUE TO THAW AND WIND ACTION. THE LARGER
TRIBUTARIES AND MAINSTEM RED RIVER ARE STILL QUITE FROZEN WITH SOME
AREAS SHOWING EVIDENCE OF VERY LOCALIZED SNOWMELT RUNOFF AND SOME
POOLING WATER AT EDGES OF THICK RIVER CHANNEL ICE.

- NORTHERN THIRD OF RED RIVER VALLEY.
NORTH AND EAST FROM GRAND FORKS THE AMOUNT OF SURFACE SNOWCOVER
RAPIDLY INCREASES TO OVER 50 PERCENT...WITH MODERATE SNOWPACK SHOWING
IN DITCHES AND FIELD SHELTERBELTS. NORTH AND EAST FROM OSLO IS
SHOWING OVER 75 PERCENT SNOWCOVER AND MORE SIGNIFICANT SNOWPACK IN
DITCHES AND SHELTERBELTS. STREAMS AND RIVERS ARE STILL ICE AND SNOW
COVERED WITH LITTLE OR NO MELT WATER SHOWING IN THEIR CHANNELS OR
IN CONTRIBUTING DITCHES. WEST FROM GRAND FORKS THROUGH DEVILS
LAKE THERE IS QUITE SPARSE SNOWCOVER AND MINIMAL SNOW IN EITHER
DITCHES OR SHELTER BELTS. THE UPPER DEVILS LAKE BASIN REMAINS MOSTLY
SNOW COVERED.

WEATHER FORECAST FOR THE VERNAL EQUINOX...MARCH 20TH...AND THE WEEK
BEYOND:

BAD NEWS 1 - SNOW IS ON THE WAY FOR THE NORTH BASIN.
WIDESPREAD ACCUMULATING LIGHT RAIN OR SNOW IS EXPECTED FROM LATE
AFTERNOON ACROSS NORTHEAST ND...INTO EARLY EVENING ACROSS NORTHWEST
MN...BECOMING WIDESPREAD AND ACCUMULATING SNOWFALL OVERNIGHT AND ON
FRIDAY. THOUGH HEAVY SNOWFALL IS POSSIBLE...THE OVERALL MOISTURE
GAIN SHOULD STAY WELL WITHIN SEASONAL NORMALS AND NOT SIGNIFICANTLY
ALTER THE CURRENT SNOWMELT FLOOD RISKS FOR THESE AREAS.

BAD NEWS 2 - A BIG COOL DOWN IS EXPECTED FOR THE COMING WEEKEND.
FOLLOWING THE STORM PASSAGE ON FRIDAY...TEMPERATURES ARE EXPECTED
TO DROP WELL BELOW SEASONAL NORMALS WITH HIGH TEMPERATURES
GENERALLY STAYING BELOW THE THAW POINT THROUGH NEXT TUESDAY.

BAD NEWS 3 - A GENERALLY COOLER THAN NORMAL PATTERN IS EXPECTED FROM
LATE MARCH INTO APRIL...WITH TEMPERATURES FOR APRIL EXPECTED TO
AVERAGE 2 TO 4 DEGREES BELOW LONG TERM NORMALS.

THE GOOD NEWS - SLIGHTLY STORMIER/WETTER/SNOWIER THAN NORMAL
CONDITIONS ARE EXPECTED TO LAST INTO EARLY APRIL... BUT OVERALL
WEATHER PATTERNS DO NOT CURRENTLY SUGGEST ANY WIDESPREAD HEAVY SNOW
NEXT WEEK. ALSO...THE RISK FOR SIGNIFICANTLY HEAVY/ABOVE NORMAL
PRECIPITATION THROUGH APRIL APPEARS LOW.

SO...GIVEN THE CURRENT STATE OF THE SNOWPACK AND RIVER ICE...AND
WITH EXPECTATIONS OF A CONTINUED SLOW/DELAYED THAW CYCLE...THE
CONDITIONAL RISKS FOR SPRING SNOWMELT FLOODING ARE CONSIDERED WELL
WITHIN THE PROBABILISTIC VALUES RELEASED ON MARCH 6TH...AND VERY NEAR
HISTORICAL NORMALS. THUS...

     NO UPDATES TO THE PROBABILISTIC HYDROLOGIC OUTLOOKS
     ARE EXPECTED AT THIS TIME. ACTUAL 7-DAY DETERMINISTIC
     FLOOD FORECASTS FOR RIVER LOCATIONS WILL BE ISSUED
     ONCE THE SNOWMELT THAW CYCLE BEGINS IN EARNEST AND WE
     EXPECT A RIVER FORECAST LOCATION TO BE IN FLOOD WITHIN
     THE 7-DAY FORECAST PERIOD.

PLEASE REMEMBER:

 * ICE JAM FLOODING IS POSSIBLE DURING BREAKUP ESPECIALLY IN TIGHT
    RIVER BENDS, UPSTREAM OF BRIDGES, OR NEAR RIVER CONFLUENCES. THEY
     CAN HAPPEN QUICKLY WITH FLOODWATER BACKING-UP UPSTREAM
      AND...ONCE THE WATER IN BACK OF THE JAM GETS HIGH ENOUGH TO
       BREAK THE ICE JAM...CAN RELEASE THE WATER SO THAT THE
        DOWNSTREAM REACH OF THE RIVER WILL HAVE FLOOD DAMAGE. IF YOU
         ARE AWARE OF ANY ICE JAMMING...PLEASE REPORT THIS TO LOCAL
          LAW ENFORCEMENT SO THEY CAN RELAY IT TO US OR DIRECTLY TO
           OUR NWS WEATHER FORECAST OFFICE AT 1.800.667.1218. OR ON
            OUR FACEBOOK PAGE OR TWITTER AT #RRNFLOOD2014.

 * AS IT GETS LATER INTO THE SPRING SNOWMELT SEASON...THE NATIONAL
    WEATHER SERVICE OFFICE IN GRAND FORKS WILL BE CLOSELY MONITORING
     WEATHER AND RIVER CONDITIONS AND WILL UPDATE THESE SPRING THAW
      PROGRESS REPORTS PERIODICALLY DURING THE NEXT FEW WEEKS AS WE
       SEE CONDITIONS CHANGING OR UNTIL THE SNOWPACK MELTS.

 * FLOOD WARNINGS AND STATEMENTS...AS WELL AS 7-DAY RIVER FORECASTS
    WILL BE ISSUED WHEN RIVER FORECAST POINTS ARE EXPECTED TO REACH
     OR EXCEED FLOOD STAGE WITHIN THAT FORECAST PERIOD.

THE 7-DAY FORECASTS ARE PRESENTED AS TEXT PRODUCTS OF DAILY RIVER
STAGES AT ESTABLISHED RIVER FORECAST LOCATIONS AND HYDROGRAPHS OF
6 HOUR RIVER STAGES FOR THE PREVIOUS 3 DAYS AND FOR THE NEXT 7 DAYS.
THESE GRAPHS AND TEXT PRODUCTS ARE AVAILABLE FROM THE NWS GRAND FORKS
AHPS WEB PAGE ON THE INTERNET AT:

                  WWW.WEATHER.GOV/GRANDFORKS

THEN CLICK ON THE "RIVERS AND LAKES AHPS" TAB ABOVE THE MAP OR THE
LINK IN THE MENU ON THE LEFT SIDE OF THE WEB PAGE.

IF YOU HAVE ANY QUESTIONS...CONTACT THE NWS AT 701-772-0720.



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