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Flood Potential Outlook
Issued by NWS Denver/Boulder, CO

000
FGUS75 KBOU 272010
ESFBOU
COC001-031-035-057-059-069-087-115-123-102359-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
210 PM MDT WED MAR 27 2013

IN TABLE 1 BELOW, THE CURRENT (CS) AND HISTORICAL (HS) OR NORMAL
PROBABILITIES OF EXCEEDING MINOR...MODERATE...AND MAJOR FLOOD STAGES
ARE LISTED FOR THE VALID TIME PERIOD.

CS VALUES INDICATE THE PROBABILITY OF REACHING A FLOOD CATEGORY
BASED ON CURRENT CONDITIONS.

HS VALUES INDICATE THE PROBABILITY OF REACHING A FLOOD CATEGORY
BASED ON HISTORICAL OR NORMAL CONDITIONS.

WHEN THE VALUE OF CS IS GREATER THAN HS...THE PROBABILITY OF
EXCEEDING THAT LEVEL IS HIGHER THAN NORMAL. WHEN THE VALUE OF CS IS
LESS THAN HS...THE PROBABILITY OF EXCEEDING THAT LEVEL IS LOWER
THAN NORMAL.

...TABLE 1--PROBABILITIES FOR MINOR...MODERATE AND MAJOR FLOODING...
                  VALID PERIOD:  3/30/2013 - 9/30/2013

                                       :    CURRENT AND HISTORICAL
                                       :     CHANCES OF EXCEEDING
                                       :       FLOOD CATERGORIES
                                       :      AS A PERCENTAGE (%)
                      CATEGORICAL      :
                   FLOOD STAGES (FT)   :   MINOR    MODERATE   MAJOR
LOCATION           MINOR   MOD   MAJOR :  CS   HS   CS   HS   CS   HS
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:SOUTH PLATTE RIVER
SOUTH PLATTE         7.0    9.0   11.0 :  <5    9   <5   <5   <5   <5
DENVER              11.0   12.5   14.0 :  <5   <5   <5   <5   <5   <5
HENDERSON           10.0   11.0   15.0 :   5    5   <5   <5   <5   <5
KERSEY              10.0   11.5   12.0 :  11   13   <5    5   <5   <5
WELDONA             10.0   11.0   13.0 :   5    7   <5   <5   <5   <5
BALZAC              10.0   11.0   13.0 :   8    8   <5    5   <5   <5
JULESBURG           10.0   12.0   13.0 :   6    8   <5   <5   <5   <5
:PLUM CREEK
SEDALIA              8.0   10.0   12.0 :  <5   <5   <5   <5   <5   <5
:BEAR CREEK
MORRISON             9.0   10.0   11.0 :  <5   <5   <5   <5   <5   <5
SHERIDAN             8.0   10.0   11.0 :  <5   <5   <5   <5   <5   <5
:CLEAR CREEK
GOLDEN              10.0   13.0   14.0 :  <5   <5   <5   <5   <5   <5
DERBY                9.0   10.5   11.5 :  <5   <5   <5   <5   <5   <5
:N FK BIG THOMPSON RIVER
DRAKE                6.0    7.0    8.0 :  <5   <5   <5   <5   <5   <5
:CACHE LA POUDRE RIVER
FORT COLLINS 9NW     7.5    9.0   10.5 :  <5   <5   <5   <5   <5   <5
FORT COLLINS        10.5   11.5   13.0 :  <5   <5   <5   <5   <5   <5
GREELEY              8.0    9.5   11.0 :   5    8   <5   <5   <5   <5
:NORTH PLATTE RIVER
NORTHGATE            8.0    9.5   11.0 :  <5    6   <5   <5   <5   <5

LEGEND
CS = CONDITIONAL SIMULATION (CURRENT OUTLOOK)
HS = HISTORICAL SIMULATION
FT = FEET

IN TABLE 2 BELOW...THE 95 THROUGH 5 PERCENT COLUMNS INDICATE THE
PROBABILITY OF EXCEEDING THE LISTED STAGE LEVELS (FT) FOR THE VALID
TIME PERIOD.

...TABLE 2--EXCEEDANCE PROBABILITIES...

                              CHANCE OF EXCEEDING STAGES
                                 AT SPECIFIC LOCATIONS

LOCATION              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:SOUTH PLATTE RIVER
SOUTH PLATTE          3.9    4.0    4.0    4.2    4.5    5.1    6.0
DENVER                4.6    5.0    5.2    5.6    6.3    6.8    7.3
HENDERSON             5.8    6.2    6.7    7.1    8.0    8.9    9.9
KERSEY                4.5    5.1    5.8    6.9    8.0   10.3   11.1
WELDONA               3.7    4.4    4.9    5.9    7.3    8.8   10.2
BALZAC                4.3    4.9    5.7    6.7    8.1    9.6   10.3
JULESBURG             4.0    4.5    5.2    6.0    7.1    9.1   10.2
:PLUM CREEK
SEDALIA               4.4    4.5    4.6    4.7    5.0    5.4    6.0
:BEAR CREEK
MORRISON              6.3    6.4    6.6    6.8    7.1    7.4    7.6
SHERIDAN              2.9    3.1    3.2    3.5    4.0    4.5    4.8
:CLEAR CREEK
GOLDEN                5.1    5.1    5.3    5.6    6.1    6.5    7.0
DERBY                 1.8    2.0    2.2    2.4    3.1    3.5    4.0
:N FK BIG THOMPSON RIVER
DRAKE                 3.9    4.0    4.1    4.2    4.3    4.6    4.7
:CACHE LA POUDRE RIVER
FORT COLLINS 9NW      3.5    3.7    3.8    4.0    4.2    4.7    5.5
FORT COLLINS          2.7    2.9    3.1    3.3    3.8    4.8    7.2
GREELEY               2.3    2.4    3.1    4.2    4.9    6.3    7.9
:NORTH PLATTE RIVER
NORTHGATE             3.0    3.1    3.3    3.8    4.6    5.2    5.5

THESE LONG-RANGE PROBABILISTIC OUTLOOKS CONTAIN FORECAST VALUES THAT
ARE CALCULATED USING MULTIPLE SEASON SCENARIOS FROM 30 OR MORE YEARS
OF CLIMATOLOGICAL DATA...INCLUDING CURRENT CONDITIONS OF THE
RIVER...SOIL MOISTURE...SNOW COVER...AND 30 TO 90 DAY LONG-RANGE
OUTLOOKS OF TEMPERATURE AND PRECIPITATION. BY PROVIDING A RANGE
OF PROBABILITIES...THE LEVEL OF RISK ASSOCIATED WITH LONG-RANGE
PLANNING DECISIONS CAN BE DETERMINED. THESE PROBABILISTIC
FORECASTS ARE PART OF THE NATIONAL WEATHER SERVICE`S ADVANCED
HYDROLOGIC PREDICTION SERVICE.

ALL OF THIS INFORMATION IS ALSO AVAILABLE IN GRAPHICAL FORMAT
ON THE INTERNET AT WEATHER.GOV/BOU.

THE NEXT OUTLOOK WILL BE ISSUED TOWARD THE END OF APRIL.

$$
TH