Flood Potential Outlook
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
545
FGUS73 KGRR 131422
ESFGRR
MIC005-015-025-035-037-045-057-065-067-073-075-077-081-085-
105-107-117-121-123-127-133-139-159-261600-
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE Grand Rapids MI
720 AM EDT Thu Mar 13 2025
...2025 SPRING FLOOD AND WATER RESOURCES OUTLOOK NUMBER 3...
This Spring Flood and Water Resources Outlook is for the rivers in
Southwest Lower Michigan.
...Flood Outlook Highlights...
The overall flood risk through the remainder of spring remains below
average in Southwest and West-Central Michigan (Grand, Kalamazoo,
and Muskegon River basins). This reduced risk is mainly because the
winter snowpack and river ice have already melted, river levels are
near or below average, and drier-than-normal soil moisture conditions
persist.
...Flood Terminology...
The term minor flooding is used to indicate minimal or no property
damage. However, some public inconvenience is possible.
The term moderate flooding is used to indicate some inundation of
structures and roads near streams. Some evacuations of people and/or
transfer of property to higher elevations may be needed.
The term major flooding is used to indicate extensive inundation of
structures and roads. Significant evacuations of people and/or
transfer of property to higher elevations will be needed.
...Probabilistic Outlook...
The flood risk this spring is below normal in all river basins in
Southwest and West-Central Lower Michigan. The chance of reaching
minor flood levels this spring currently stands at less than 40% at
all of the forecast locations on our rivers.
...Past Precipitation...
The fall and early winter period was much drier than normal.
Precipitation totals moved closer to normal for December, before
dropping well-below normal again in January and February. So far
March has been fairly normal in terms of total precipitation. In
general, it was a fairly cold and relatively dry winter.
...River Conditions...
Water levels on all of our major rivers are significantly lower than
normal for this time of year. With the snowpack already melted,
future water level rises will be tied completely to rain events.
...Soil Moisture and Frost Depths...
Soil moisture is significantly below average (drier than normal)
across virtually all of Lower Michigan. This is primarily due to the
very dry fall and early winter period - thus the soils stand ready to
absorb a higher-than-normal amount of spring meltwater and rainfall.
Meanwhile, limited frozen ground across parts of West Michigan has
now thawed, and will not be a contributor to future flood risks.
...Snow Cover and Liquid Water Content...
The snowpack has fully melted across virtually the entire area. There
remains about 2 inches of snow water equivalent on the ground around
Houghton Lake (extreme headwaters of the Muskegon River basin), but
this snow water is not enough to contribute to future flood risks
significantly.
...River Ice Conditions...
The vast majority of all river ice has melted out, especially across
the Kalamazoo and Grand Rivers. The breakup icejam risk is very low,
and will be zero soon.
...Weather Outlook.
Heavy spring rains are always the single biggest factor affecting our
flood risks, and this will be even more true for the remainder of
this spring. At this time, the next few weeks looks active with rain
chances every few days, but none of these look (at this time) like
heavy rain producers that would significantly increase flood
concerns.
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 more 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: 03/17/2025 - 06/15/2025
: 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
-------- ----- ----- ----- : --- --- --- --- --- ---
:Grand River
Jackson 14.0 15.0 16.0 : 15 28 <5 5 <5 <5
:Buck Creek
Grandville 9.0 10.5 12.0 : 9 12 5 5 <5 <5
:Grand River
Eaton Rapids 6.0 8.0 9.0 : <5 <5 <5 <5 <5 <5
Dimondale 13.0 14.0 16.0 : <5 <5 <5 <5 <5 <5
:Red Cedar River
Williamston 9.0 10.0 10.5 : <5 <5 <5 <5 <5 <5
East Lansing 7.0 10.0 13.0 : 13 20 <5 <5 <5 <5
:Sycamore Creek
Holt 8.0 9.0 10.0 : 38 34 6 7 <5 <5
:Grand River
Lansing 11.0 13.0 15.0 : <5 9 <5 <5 <5 <5
Grand Ledge 11.0 13.0 15.0 : <5 <5 <5 <5 <5 <5
Portland 12.0 14.0 16.0 : <5 <5 <5 <5 <5 <5
:Looking Glass River
Eagle 7.0 9.0 11.0 : 28 38 <5 8 <5 <5
:Maple River
Maple Rapids 9.0 11.0 13.0 : 31 60 <5 <5 <5 <5
:Grand River
Ionia 21.0 23.0 25.0 : 10 17 <5 <5 <5 <5
:Flat River
Smyrna 8.5 9.5 10.5 : <5 <5 <5 <5 <5 <5
:Grand River
Lowell 15.0 18.0 20.0 : <5 15 <5 <5 <5 <5
:Thornapple River
Hastings 7.0 9.0 10.0 : 20 35 <5 <5 <5 <5
Caledonia 10.0 12.0 14.0 : <5 14 <5 <5 <5 <5
:Grand River
Ada 20.0 22.0 25.0 : <5 9 <5 <5 <5 <5
:Rogue River
Rockford 8.0 10.0 11.0 : 6 17 <5 <5 <5 <5
:Grand River
Grand Rapids 18.0 21.0 23.0 : <5 13 <5 <5 <5 <5
:Pere Marquette River
Scottville 5.5 6.5 7.0 : <5 <5 <5 <5 <5 <5
:White River
Whitehall 6.0 7.0 8.0 : <5 9 <5 <5 <5 <5
:Muskegon River
Evart 12.0 13.0 14.0 : 5 25 <5 9 <5 6
:Little Muskegon River
Morley 6.0 7.0 8.0 : <5 <5 <5 <5 <5 <5
:Muskegon River
Croton 9.0 11.0 12.0 : 8 39 <5 <5 <5 <5
Newaygo 11.0 14.0 15.0 : 17 56 <5 10 <5 5
Bridgeton 13.0 16.0 17.0 : 13 53 <5 10 <5 5
:Kalamazoo River
Marshall 8.0 9.0 10.0 : <5 10 <5 8 <5 7
:Battle Creek
Battle Creek 4.0 5.0 6.0 : <5 <5 <5 <5 <5 <5
:Kalamazoo River
Battle Creek 9.0 10.0 11.0 : <5 <5 <5 <5 <5 <5
Comstock 9.0 10.0 11.0 : <5 10 <5 <5 <5 <5
New Richmond 17.0 19.0 21.0 : <5 6 <5 <5 <5 <5
:St. Joseph River
Burlington 6.5 9.0 11.0 : <5 12 <5 <5 <5 <5
:Portage River
Vicksburg 5.5 7.0 8.0 : <5 6 <5 <5 <5 <5
:Chippewa River
Mt. Pleasant 8.0 11.0 13.0 : <5 16 <5 <5 <5 <5
:Pine River
Alma 8.0 10.0 12.0 : <5 15 <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: 03/17/2025 - 06/15/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Grand River
Jackson 11.5 11.7 12.3 12.8 13.2 14.1 14.3
:Buck Creek
Grandville 6.0 6.5 6.8 7.4 8.3 8.9 10.8
:Grand River
Eaton Rapids 4.0 4.1 4.1 4.3 4.6 5.1 5.3
Dimondale 6.6 6.6 7.0 7.5 8.2 9.3 9.7
:Red Cedar River
Williamston 5.1 5.2 6.0 6.6 7.3 8.0 8.3
East Lansing 4.9 5.0 5.1 5.7 6.5 7.6 8.1
:Sycamore Creek
Holt 6.0 6.2 6.9 7.5 8.3 8.8 9.0
:Grand River
Lansing 5.8 5.8 6.2 7.2 8.1 10.5 10.7
Grand Ledge 6.2 6.2 6.4 7.0 7.6 9.0 9.1
Portland 7.1 7.2 7.7 8.3 9.2 10.4 10.5
:Looking Glass River
Eagle 4.7 4.9 5.4 6.1 7.1 8.4 8.9
:Maple River
Maple Rapids 7.0 7.1 7.8 8.5 9.1 10.0 10.2
:Grand River
Ionia 12.5 13.1 14.2 16.9 18.8 21.0 21.5
:Flat River
Smyrna 4.1 4.1 4.6 4.9 5.5 6.7 7.1
:Grand River
Lowell 7.5 7.8 8.6 9.9 11.4 14.3 14.8
:Thornapple River
Hastings 4.2 4.4 4.8 5.3 6.7 7.5 8.3
Caledonia 4.6 4.9 5.4 5.8 7.5 9.3 9.8
:Grand River
Ada 10.1 10.6 11.8 13.6 15.7 18.6 19.2
:Rogue River
Rockford 4.5 4.9 5.1 5.8 6.4 7.5 8.1
:Grand River
Grand Rapids 5.9 6.5 8.3 10.4 12.9 16.7 17.5
:Pere Marquette River
Scottville 3.0 3.0 3.1 3.6 4.2 4.6 4.8
:White River
Whitehall 3.0 3.0 3.5 4.0 5.0 5.6 5.9
:Muskegon River
Evart 9.5 9.5 9.5 9.6 10.3 11.4 12.2
:Little Muskegon River
Morley 2.7 2.8 3.0 3.4 3.9 4.7 4.9
:Muskegon River
Croton 6.9 7.0 7.0 7.3 7.9 8.7 9.4
Newaygo 9.4 9.4 9.5 9.8 10.6 11.5 12.5
Bridgeton 10.5 10.5 10.6 11.1 12.2 13.5 14.7
:Kalamazoo River
Marshall 5.1 5.1 5.3 5.7 6.5 6.8 7.4
:Battle Creek
Battle Creek 1.3 1.4 1.5 1.8 2.1 2.5 2.6
:Kalamazoo River
Battle Creek 3.8 3.9 4.1 4.5 5.0 5.8 6.2
Comstock 4.9 4.9 5.1 5.8 6.5 7.9 8.2
New Richmond 12.9 13.1 13.6 14.1 14.8 15.9 16.3
:St. Joseph River
Burlington 4.4 4.5 4.9 5.2 5.7 6.0 6.4
:Portage River
Vicksburg 4.1 4.3 4.5 4.8 5.0 5.3 5.4
:Chippewa River
Mt. Pleasant 4.2 4.3 4.7 5.1 5.9 6.8 7.4
:Pine River
Alma 2.6 3.2 3.6 4.6 5.8 6.7 7.4
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: 03/17/2025 - 06/15/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Grand River
Jackson 0.1 0.1 0.1 0.1 0.1 0.1 0.1
:Buck Creek
Grandville 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Grand River
Eaton Rapids 0.6 0.5 0.4 0.4 0.3 0.3 0.2
Dimondale 0.7 0.6 0.5 0.4 0.3 0.3 0.3
:Red Cedar River
Williamston 0.1 0.0 0.0 0.0 0.0 0.0 0.0
East Lansing 0.1 0.1 0.1 0.1 0.1 0.0 0.0
:Sycamore Creek
Holt 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Grand River
Lansing 0.9 0.8 0.7 0.6 0.5 0.4 0.4
Grand Ledge 0.9 0.8 0.7 0.6 0.5 0.4 0.4
Portland 1.0 0.9 0.8 0.6 0.5 0.5 0.4
:Looking Glass River
Eagle 0.1 0.1 0.1 0.1 0.1 0.0 0.0
:Maple River
Maple Rapids 0.1 0.1 0.1 0.1 0.1 0.1 0.0
:Grand River
Ionia 1.9 1.7 1.5 1.2 1.1 0.9 0.7
:Flat River
Smyrna 0.4 0.3 0.3 0.2 0.2 0.2 0.2
:Grand River
Lowell 2.4 2.3 2.0 1.7 1.4 1.2 1.0
:Thornapple River
Hastings 0.2 0.2 0.2 0.2 0.1 0.1 0.1
Caledonia 0.5 0.5 0.4 0.4 0.3 0.3 0.2
:Grand River
Ada 3.0 2.8 2.5 2.1 1.8 1.6 1.3
:Rogue River
Rockford 0.2 0.2 0.1 0.1 0.1 0.1 0.1
:Grand River
Grand Rapids 3.2 3.1 2.8 2.3 2.0 1.7 1.4
:Pere Marquette River
Scottville 0.6 0.6 0.5 0.5 0.5 0.4 0.4
:White River
Whitehall 0.4 0.4 0.3 0.3 0.3 0.3 0.3
:Muskegon River
Evart 1.1 1.0 0.9 0.7 0.6 0.5 0.5
:Little Muskegon River
Morley 0.1 0.1 0.1 0.1 0.1 0.1 0.1
:Muskegon River
Croton 1.8 1.8 1.6 1.4 1.2 1.1 1.0
Newaygo 1.9 1.9 1.7 1.5 1.3 1.1 1.1
Bridgeton 2.0 1.9 1.7 1.5 1.3 1.2 1.1
:Kalamazoo River
Marshall 0.3 0.3 0.1 0.1 0.1 0.1 0.1
:Battle Creek
Battle Creek 0.2 0.2 0.2 0.2 0.1 0.1 0.1
:Kalamazoo River
Battle Creek 0.6 0.6 0.5 0.5 0.5 0.4 0.3
Comstock 0.9 0.8 0.8 0.7 0.6 0.6 0.5
New Richmond 1.7 1.6 1.4 1.3 1.0 0.8 0.7
:St. Joseph River
Burlington 0.2 0.2 0.2 0.1 0.1 0.1 0.1
:Portage River
Vicksburg 0.1 0.1 0.1 0.1 0.1 0.1 0.0
:Chippewa River
Mt. Pleasant 0.2 0.2 0.2 0.2 0.1 0.1 0.1
:Pine River
Alma 0.2 0.1 0.1 0.1 0.1 0.1 0.1
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/grr for more weather and water
information.
The next outlook will be issued near the end of March.
$$