Flood Potential Outlook
Issued by NWS Cheyenne, WY

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000
FGUS75 KCYS 282136
ESFCYS
NEC007-013-033-045-105-123-157-165-WYC001-007-009-015-021-027-031-
290545-

Probabilistic Hydrologic Outlook
National Weather Service Cheyenne WY
236 PM MST Wed Feb 28 2024

In Table 1 below, the current (CS) and historical (HS) or normal
probabilities of exceeding minor...moderate...and major flood stage
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: 02/17/2024  - 09/30/2024

                                       :    Current and Historical
                                       :     Chances of Exceeding
                                       :       Flood Categories
                                       :      as a Percentage (%)
                      Categorical      :
                   Flood Stages (FT)   :   Minor    Moderate   Major
Location           Minor   Mod   Major :  CS   HS   CS   HS   CS   HS
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:Encampment River
Encampment           6.5    7.5    8.5 :  <5   <5   <5   <5   <5   <5
:North Platte River
Saratoga             8.5    9.5   10.5 :  32   40   12   17   <5   <5
Sinclair             9.0   10.0   11.0 :  28   31   12   17    5    6
:Medicine Box River
Hanna                6.0    7.0    8.0 :  <5   <5   <5   <5   <5   <5
:North Platte River
Glenrock             7.0    8.0    9.0 :  <5   <5   <5   <5   <5   <5
Orin                 8.0    9.0   10.0 :  <5   <5   <5   <5   <5   <5
:Laramie River
Woods Landing        6.0    6.5    7.0 :  <5    5   <5   <5   <5   <5
Laramie              9.0   10.0   11.0 :  10   22   <5    6   <5   <5
Bosler               7.5    8.5    9.5 :  <5    8   <5   <5   <5   <5
Fort Laramie         7.0    8.0    9.0 :  <5    7   <5   <5   <5   <5
:North Platte River
Henry                5.5    6.5    7.5 :  <5   <5   <5   <5   <5   <5
Mitchell             7.5    8.5    9.5 :   5   14   <5    8   <5    5
Minatare             7.5    8.5    9.5 :  <5    6   <5   <5   <5   <5
Bridgeport           9.5   10.0   10.5 :  <5   <5   <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
                           Valid Period: 02/17/2024  - 09/30/2024
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Encampment River
Encampment            4.1    4.3    4.6    4.9    5.3    5.5    6.1
:North Platte River
Saratoga              6.2    6.6    7.4    8.1    8.9    9.6   10.0
Sinclair              5.4    5.9    6.9    7.9    9.1   10.2   10.8
:Medicine Box River
Hanna                 3.2    3.2    3.6    4.2    4.4    4.8    5.2
:North Platte River
Glenrock              2.7    2.8    2.9    3.0    3.2    3.4    4.3
Orin                  4.7    4.8    4.9    5.0    5.1    5.6    5.9
:Laramie River
Woods Landing         2.0    2.0    2.3    2.8    3.4    4.0    4.5
Laramie               4.8    5.1    6.0    7.4    8.2    9.0    9.3
Bosler                1.3    1.3    1.7    3.0    5.4    6.2    6.6
Fort Laramie          3.0    3.2    3.4    3.5    4.2    5.6    6.1
:North Platte River
Henry                 3.5    3.6    3.7    3.8    3.9    4.1    4.4
Mitchell              3.0    3.1    3.4    3.8    4.6    6.5    7.4
Minatare              3.6    3.7    3.9    4.4    4.8    6.1    6.6
Bridgeport            5.0    5.0    5.2    5.6    6.0    6.8    7.2

In Table 3 below...the 95 through 5 percent columns indicate the
probability of falling below the listed stage levels (FT) for
the valid time period.

...Table 3--Nonexceedance Probabilities...

                            Chance of Falling Below Stages
                                 at Specific Locations
                           Valid Period: 02/17/2024  - 09/30/2024
LOCATION              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Encampment River
Encampment            1.8    1.8    1.7    1.7    1.6    1.5    1.4
:North Platte River
Saratoga              3.6    3.6    3.6    3.6    3.5    3.5    3.3
Sinclair              3.2    3.2    3.2    3.2    3.1    3.1    2.7
:Medicine Box River
Hanna                 2.1    2.1    2.1    2.0    2.0    2.0    1.9
:North Platte River
Glenrock              0.9    0.9    0.9    0.9    0.8    0.8    0.8
Orin                  3.5    3.5    3.5    3.5    3.5    3.5    3.5
:Laramie River
Woods Landing         1.2    1.2    1.0    0.3    0.3    0.3    0.3
Laramie               3.8    3.7    3.7    3.6    3.6    3.5    3.5
Bosler                0.9    0.8    0.7    0.7    0.7    0.7    0.7
Fort Laramie          2.4    2.4    2.4    2.4    2.4    2.4    2.4
:North Platte River
Henry                 2.0    2.0    2.0    2.0    2.0    2.0    2.0
Mitchell              0.8    0.6    0.3    0.1    0.1    0.1    0.1
Minatare              1.7    1.7    1.6    1.6    1.6    1.6    1.5
Bridgeport            3.9    3.9    3.8    3.8    3.8    3.8    3.8

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.

Visit our web site weather.gov/cys for more weather and water
information.

The next outlook will be issued in the middle of March.


$$

AJA


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