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FGUS73 KAPX 272037
ESFAPX
MIZ016>018-020>036-041-042-086>088-095>099-062000-

Hydrologic Outlook
National Weather Service Gaylord MI
337 PM EST Thu Feb 27 2025

...Spring 2025 Flood Outlook #2 for Northern Michigan...

The Spring 2025 Flood Outlook for Northern Michigan indicates a near
to above average probability of flooding due to snow melt within
major eastern Upper and northern Lower Michigan river basins.

This outlook covers Chippewa and Mackinac counties in eastern Upper
Michigan which includes the Pine River Basin...and the northern half
of Lower Michigan encompassing Au Sable...Boardman...Manistee...
Rifle...and Tobacco River basins.

The first table below lists the probabilities of reaching flood stage
(minor flooding)...as well as moderate and major flood levels for the
six forecast points within the Gaylord National Weather Service office
Hydrologic Service Area. Current (CS) and historical (HS) 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: 03/03/2025 - 06/01/2025

                                       :    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
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:MANISTEE RIVER
SHERMAN             15.0   16.0   17.0 :  57   12    7   <5   <5   <5
:BOARDMAN RIVER
MAYFIELD--BROWN B    7.0    8.0    9.0 :  <5   <5   <5   <5   <5   <5
:AU SABLE RIVER
RED OAK              7.0    8.0    9.0 :  50   12   13   <5   <5   <5
:RIFLE RIVER
STERLING             6.0   11.0   13.0 :  69   64   <5   <5   <5   <5
:PINE RIVER
RUDYARD             17.0   19.0   20.0 :  <5   <5   <5   <5   <5   <5
:TOBACCO RIVER
BEAVERTON           12.0   14.0   17.0 :  <5   <5   <5   <5   <5   <5


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

Departure from normal of reaching flood stage is the difference between
the current projected chance for reaching flood stage (CS) and the
climatological normal (HS). For example...the Manistee River near
Sherman...with a Flood Stage of 15 feet...has a 57 percent chance of
reaching or exceeding flood stage. This is 45 percentage points above
normal. During the 90 day period listed... the typical probability
of the Manistee River near Sherman reaching flood stage is 12 percent.

The next table shows the chance that a particular river location could
rise above the listed stages in the specified 90 day period (high flow
forecast):

...TABLE 2: Exceedance Probabilities...

                               CHANCE OF EXCEEDING STAGES
                                  AT SPECIFIC LOCATIONS
                          VALID PERIOD: 03/03/2025 - 06/01/2025
LOCATION              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:MANISTEE RIVER
SHERMAN              14.5   14.5   14.8   15.1   15.5   15.8   16.1
:BOARDMAN RIVER
MAYFIELD--BROWN B     4.5    4.6    4.7    5.0    5.2    5.4    5.6
:AU SABLE RIVER
RED OAK               5.7    6.0    6.3    7.0    7.6    8.1    8.5
:RIFLE RIVER
STERLING              4.5    5.0    5.7    6.5    7.2    8.9    9.5
:PINE RIVER
RUDYARD               7.2    8.0    9.8   11.1   12.9   13.9   15.0
:TOBACCO RIVER
BEAVERTON             5.2    5.5    5.9    6.4    7.0    8.2    8.9

Current forecasts suggest probabilities of exceeding flood stage are
around 50 percent on the Manistee River near Sherman...the Au Sable
River near Red Oak...and the Rifle River near Sterling.  Elsewhere the
probability of exceeding flood stage is less than 5 percent.

The last table indicates the chance that a particular river location
could fall below the listed stages in the specified 90 day period
(low flow forecast):

...TABLE 3: Non-exceedance Probabilities...

                            CHANCE OF FALLING BELOW STAGES
                                 AT SPECIFIC LOCATIONS
                          VALID PERIOD: 03/03/2025 - 06/01/2025
LOCATION              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:MANISTEE RIVER
SHERMAN               0.7    0.7    0.7    0.7    0.7    0.7    0.7
:BOARDMAN RIVER
MAYFIELD--BROWN B     0.1    0.1    0.1    0.1    0.1    0.1    0.1
:AU SABLE RIVER
RED OAK               0.6    0.6    0.6    0.6    0.6    0.6    0.6
:RIFLE RIVER
STERLING              0.2    0.2    0.2    0.2    0.2    0.2    0.2
:PINE RIVER
RUDYARD               0.1    0.1    0.1    0.1    0.1    0.1    0.1
:TOBACCO RIVER
BEAVERTON             0.2    0.2    0.2    0.2    0.2    0.2    0.2

Spring flood outlooks are routinely issued in February and March in
order to give advance notice of possible flooding.  The long range
probabilistic outlooks given in the above tables contain forecast
values that are calculated using multiple season scenarios from 30
or more years of climatological data...and incorporated current
river levels...soil moisture conditions...snow water equivalent
values...as well as 30 and 90 day outlooks for temperature and
precipitation provided by the NOAA/NWS Climate Prediction Center.
Actual river crests will differ from this outlook if future
conditions differ significantly from forecast conditions...or if
ice jams develop.

...Current Conditions...

Above normal snowfall and snowpack is contributing to the above normal
flood probabilities at several gaging locations across northern
Michigan.

Precipitation through the Summer months (June-August) was generally
from 75 to 125 percent of normal. Across eastern Upper Michigan June
was the wettest month of the summer with precipitation 150 to 200+
percent of normal...things started to dry out in July with below
normal rainfall though most areas received at least 50 percent of
normal precipitation. A similar trend was noted in August.
Precipitation during the Fall months (September-November) started
out below normal for September (less than 50 percent of normal with
some areas less than 25 percent of normal) and October (25 to 75
percent of normal). But November precipitation was above normal in
most locations...more than 200 percent of normal across northern
Chippewa county and in the higher terrain of eastern Antrim/western
Otsego/northwest Kalkaska counties mainly due to a significant lake
effect snow event during Thanksgiving weekend.

December precipitation was above normal in most areas...with the
heaviest precipitation (150-200+ percent of normal) concentrated
over the typical northwest flow lake effect snow areas. Traverse
City recorded its second snowiest December on record (48.2 inches)...
Gaylord its fourth snowiest December (57.9 inches)...and Houghton
Lake its 9th snowiest (23.4 inches). January 2025 precipitation was
largely dependent on location relative to the Lake Superior and Lake
Michigan snowbelt areas. Precipitation departures of 150-200 percent
of normal occurred mainly between Grand Traverse Bay and the I-75
corridor in northwest Lower Michigan (bounded roughly by the M-68 and
M-72 corridors to the north and south respectively)...the typical
Lake Michigan snow belt regions. Precipitation departures of 100-125
percent of normal have occurred over northern Chippewa county
adjacent to Whitefish Bay. Sault Ste. Marie recorded their second
snowiest January on record (58.4 inches).

Through the first three weeks of February...total seasonal snowfall
is running 125 to 175 percent of normal across northern Michigan.
Sault Ste. Marie...Gaylord...Traverse City...and Houghton Lake have
all exceeded their normal seasonal snowfall total. Liquid equivalent
precipitation so far this month is running above normal across
northern Lower...with 200 to 300 percent of normal across interior
northern Lower from M-55 north to M-32. Across eastern Upper above
normal (100-150 percent of normal) precipitation has occurred around
the west side of Whitefish Bay...with precipitation a bit below
normal across eastern portions of Mackinac and Chippewa counties.
Snow water equivalent in the snow pack across eastern Upper Michigan
is generally 2 to 6 inches across Mackinac and southeast Chippewa
county...and from 6 to 9 inches across the remainder of Chippewa
county. Across northern Lower snow water equivalent ranges from 2 to
4 inches across northeast Lower...and 4 to 7 inches across northwest
Lower with highest values east of Grand Traverse Bay within the
traditional Lake Michigan snow belt. These SWE values are all normal
except across Mackinac county where snow water equivalent is in the
30th percentile.

Soil moisture is near normal across all of northern Michigan.
Streamflows on northern Michigan rivers are below normal on the Au
Sable and Manistee Rivers. Rivers are running near normal elsewhere
with fluctuations in river levels due to ice activity.

Lingering D2 (Severe) Drought conditions continue across parts of
Oscoda...Alcona...Roscommon...Ogemaw...Iosco...Gladwin...and Arenac
counties.

Moderate (D1) Drought conditions also continue across parts of
Presque Isle...Leelanau...Montmorency...Alpena...Benzie...Grand
Traverse...Kalkaska...Crawford...Manistee...Wexford...and Missaukee
counties.

...Weather Outlook...

The 6 to 10 day outlook issued by the Climate Prediction Center
valid for the period of March 5-9 2025 is leaning toward near normal
temperatures and above normal precipitation.

The outlook for the Spring (March through May) indicates no
discernible trend with regard to temperatures (equal probabilities
for above...normal...and below normal temperatures)...and a 40 to 50
percent chance of above normal precipitation.

...Additional Information...

The next Spring Flood outlook will be issued on Thursday March 13,
2025.  Long range probabilistic outlooks such as those given in the
above tables are issues during the last week of each month throughout
the year.

Visit water.noaa.gov/wfo/apx for more river information...including
graphs of the probabilistic information given in the above tables...
the latest observed conditions on northern Michigan streams...as
well as analyses of precipitation and snowfall.

$$

JPB