Flood Potential Outlook
Issued by NWS Grand Forks, ND

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000
FGUS73 KFGF 261320
ESFFGF
NDC005-027-071-301200-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS ND
0815 AM CDT FRI SEP 26 2014

...DEVILS LAKE OUTLOOK FOR FLOOD POTENTIAL...

                          DEVILS AND STUMP LAKES
                    LONG-RANGE PROBABILISTIC OUTLOOK

  THE NATIONAL WEATHER SERVICE IS PROVIDING LONG-RANGE PROBABILISTIC
   HYDROLOGIC OUTLOOKS FOR DEVILS AND STUMP LAKES BETWEEN JANUARY
    AND SEPTEMBER. THEY WILL NOT BE PROVIDED BETWEEN OCTOBER AND
     DECEMBER.

  THE AHPS GRAPHICS ASSOCIATED WITH THIS OUTLOOK WILL BE ON THE WEB
   NO LATER THAN 10:30 AM THIS FRIDAY UNDER THE EXPERIMENTAL
    LONG-RANGE FLOOD RISK TAB AT...

             WATER.WEATHER.GOV/AHPS2/INDEX.PHP?WFO=FGF

  DEPENDING ON THE SEASON, THE HIGH OR LOW WATER PROBABILITIES MAY
   BE OMITTED DUE TO THEIR APPLICABILITY TO THE HYDROLOGIC SITUATION.
    REFER TO THE SCHEDULING SECTION FARTHER ON IN THIS MESSAGE.


. CHANCES OF DEVILS AND STUMP LAKES FALLING BELOW GIVEN LAKE
LEVELS...

  THE PROBABILITY OF NOT EXCEEDING A GIVEN LAKE LEVEL IS THE
   PERCENTAGE OF LAKE LEVEL FALLS THAT ARE BELOW THAT LEVEL FOR
    ALL THE YEARS THAT WERE RUN THROUGH THE MODEL USING THE
     PRECIPITATION AND TEMPERATURES FOR THOSE YEARS DURING THE
      VALID PERIOD OF THE OUTLOOK.

  INTERPRETATION AID...THERE IS A 50 PERCENT CHANCE THAT DEVILS
   LAKE WILL FALL BELOW 1451.7 FEET DURING THE VALID PERIOD AND
    ONLY A 5 PERCENT CHANCE THAT IT WILL FALL BELOW 1451.6 FEET.

           PROBABILITIES FOR NON-EXCEEDING LISTED LAKE LEVELS

             FROM SEPTEMBER 22, 2014 TO DECEMBER 28, 2014

LOCATION              95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
DEVILS LAKE.....
  CREEL BAY         1452.0 1451.9 1451.8 1451.7 1451.7 1451.6 1451.6
STUMP LAKE.....
  EAST STUMP LAKE   1452.0 1451.9 1451.8 1451.7 1451.7 1451.6 1451.6

  THE NON-EXCEEDANCE VALUE FOR A LISTED PERCENTAGE IS THE VALUE
    WHERE THAT PERCENTAGE OF ALL MODEL CASES RUN WERE BELOW THAT
      LAKE LEVEL FOR THE SPECIFIED VALID PERIOD OF THE OUTLOOK.

. OUTLOOK SCHEDULE...

 - BETWEEN JANUARY AND MAY, ONLY THE HIGH WATER EXCEEDANCES WILL BE
    PROVIDED WITH VALID PERIODS ENDING AT THE END OF SEPTEMBER.

 - FOR JUNE AND JULY, BOTH HIGH-WATER AND LOW-WATER EXCEEDANCES
    WILL BE PROVIDED.

 - FOR AUGUST AND SEPTEMBER, ONLY THE LOW-WATER EXCEEDANCES WILL BE
    PROVIDED WITH VALID PERIODS ENDING AT THE END OF NOVEMBER.

 - NO PROBABILITY OF EXCEEDANCE/NON-EXCEEDANCE INFORMATION WILL BE
    GIVEN FROM OCTOBER THROUGH DECEMBER, SINCE LAKE FREEZE-UP
     LEVELS WILL BE GIVEN IN THE FALL OUTLOOKS PREVIOUSLY ISSUED.

. ADDITIONAL INFORMATION...

WIND AND WAVE FORECASTS FOR DEVILS AND STUMP LAKES ARE AVAILABLE FOR
A SEVEN DAY PERIOD WHEN THE LAKES ARE SUFFICIENTLY ICE-FREE AT:

           WWW.CRH.NOAA.GOV/FGF/HYDRO/LAKE_FCST.PHP

ADDITIONALLY, 7 DAY LAKE EVAPORATION FORECASTS ARE AVAILABLE
 DURING THE GROWING SEASON AT:

           WWW.CRH.NOAA.GOV/FGF/CLIMATE/FARM_INFO.PHP

THE LONG-RANGE PROBABILISTIC OUTLOOK IS BASED ON HIGH AND LOW LAKE
  LEVELS THAT WERE CALCULATED FOR THE VALID PERIOD USING MULTIPLE
  SCENARIOS OF TEMPERATURE AND PRECIPITATION FROM 1949 TO 2012 AND
  CURRENT CONDITIONS OF THE LAKE, SNOWCOVER (IN WINTER), AND SOIL
  MOISTURE.

BY PROVIDING THE COMPLETE RANGE OF LAKE LEVEL PROBABILITIES, THE
  AMOUNT OF RISK ASSOCIATED WITH LONG-RANGE PLANNING DECISIONS CAN
  BE DETERMINED. THESE PROBABILISTIC OUTLOOKS ARE PART OF NOAA`S
  NATIONAL WEATHER SERVICE`S ADVANCED HYDROLOGIC PREDICTION
  SERVICES (AHPS).

THIS OUTLOOK IS ALSO PRESENTED AS PROBABILITY GRAPHS OF LAKE HEIGHT
  FOR THE FULL PERIOD AS WELL AS WEEKLY PROBABILITIES. THE OUTLOOK
    GRAPHICS AND EXPLANATIONS THAT HELP IN INTERPRETING THESE
      OUTLOOKS ARE AVAILABLE FROM THE NWS GRAND FORKS AHPS WEB PAGE
        ON THE INTERNET AT:

             WATER.WEATHER.GOV/AHPS2/INDEX.PHP?/WFO=FGF

OUTLOOK GRAPHICS OF THE PROBABILITIES OF EXCEEDING VARIOUS LAKE
  LEVELS FOR DEVILS AND STUMP LAKES ARE ALSO ON OUT WEB SITE. THEY
  SHOULD BE AVAILABLE BY 10:30 AM FRIDAY. MONTHLY PROBABILISTIC
  OUTLOOKS ARE USUALLY ISSUED ON THE THURSDAY OR FRIDAY OF THE WEEK
  FOLLOWING THE FIRST THURSDAY AFTER THE 15TH OF THE MONTH, USUALLY
  THE THIRD OR FOURTH WEEK OF THE MONTH.

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

$$
      WEATHER.GOV/FGF
NNNN








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