Updraft Category Archive: Lakes

Lake Minnetonka: Near lowest level in 12 years; More April showers in March

Posted at 8:38 AM on March 22, 2012 by Paul Huttner (4 Comments)
Filed under: Lakes

2-3 feet drop in level of Lake Minnetonka since last spring

.20" to .40" rainfall today with spotty coverage

21 states with record highs this week

87 degrees in Chicago Wednesday

8th consecutive record high for the Windy City

70s return to the metro and southern Minnesota this weekend

Lowest water level in 12 years on lake Minnetonka.
Photo credit: Paul Huttner

Trouble on 'Tonka:

It's getting bad out there when you look at the permanent docks and boat ramps on Lake Minnetonka these days.

Looking at numbers from the Minnehaha Creek Watershed District, the level of Lake Minnetonka is near the lowest levels observed in the past 12 years!

The level of Lake Minnetonka dipped to 927.83 feet above sea level last fall and today is 927.99 feet above sea level.

Source: Minnehaha Creek Watershed District

Tonka has only dipped this low twice in the past 12 years, October 1, 2009 (927.78') and October 27, 2000. (927.37')

Just last spring Tonka was at 930.26 feet on May 23,2001...meaning the big west metro "bellwether" lake has dropped well over 2 feet since last spring.

The Gray's Bay Dam in Minnetonka at the eastern end of the lake controls the level of Lake Minnetonka, and how much water feeds into Minnehaha Creek from the lake.

The MCWD closed the dam last September as drought began to eat away at the lake level. The lake would be higher now had they closed it sooner last summer... given the onset of drought conditions and rapid fall in lake levels. But MCWD has to do a constant balancing act between those who want higher lake levels and those who want more water flowing into Minnehaha Creek.

Either way... Lake Minnetonka and Minnehaha Creek are woefully low this spring at a time of year when we should be seeing our highest levels of the year.

We'll need several inches of rain this spring on order to boost levels on lakes, rivers & ponds.

April showers today:

Bands of showers today are riding north from Iowa again. That's great news for our parched soils & low lakes, but probably not enough to put a big bite in the drought.

Coverage will be spotty, but most models indicate between .20" and .40" of rain today.

Source: ISU

There is enough energy that we may see a few thunderstorms pop today into this evening. SPC does not have any risk for severe weather in Minnesota at this point.

Source: NOAA SPC

Sunnier & warmer weekend: 70s return!

Our wet weathermaker begins to pull east of Minnesota Friday, and right now the weekend is looking sunny & milder. Temps should make the 70s again, but probably fall short of record highs in the metro. The records are 76 and 78 degrees for Saturday and Sunday at MSP Airport.

Source: ISU

Record heat in 21 states this week!

The scope, magnitude and duration of this March heat wave is impressive...and unprecedented.

As many as 21 states have set temperature records this week from Minnesota south and east.

Check out these highs on Wednesday!

Chicago 87 degrees - 8th consecutive record breaking day!
Madison 83 degrees - warmest March day on record
Green Bay 83 degrees
Marquette, MI 81 degrees - warmest March day on record

The list goes on and on, but you get the idea. We've never seen a warm March pattern like this in recorded history.

My former colleage at WGN-TV Tom Skilling has some interesting data from his Chicago Weather Center blog.

Source: Chicago Weather Center/WGN

Lilacs are leafing out at the weather lab in Minnesota a good month ahead of schedule. Tulips are blooming in Chicago.

Keep in mind our last frost on average in the metro is around April 28th. It's too soon to say for sure...but it's more than likely we'll still see frost this spring in the metro and most of Minnesota.

It would be very unusual for Minnesota not to see another frost...but then again what's been "usual" about our weather this year?

PH

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A tale of two lakes

Posted at 5:35 PM on May 16, 2011 by Paul Huttner
Filed under: Drought, Lakes

They say all weather is local.

That's been especially true lately for two metro lakes on different sides of town.

White Bear Lake and Minnetonka are both destination lakes for boaters, sailors and homeowners. But when it comes to lake water levels, two large lakes in the same metropolitan area are far apart these days.

Lake Minnetonka: "Big Water"

Map of Lake Minnetonka.
(Click to enlarge images)

Sprawling Lake Minnetonka brackets the southwest side of the metro. Some data from Hennepin County Library.

LAKE MINNETONKA - FACTS AND STATISTICS

NAME:

The meaning of the name Minnetonka is as follows: "Minne" is a term from the Sioux language meaning water; "tonka" is the term meaning big or great. from: 977.6U Upham, Warren. MINNESOTA GEOGRPAHIC NAMES, P. 224.

ISLANDS:

The number of islands in Lake Minnetonka varies according to the different definitions of islands. The 1993-revised U.S. Geological Survey topographic maps lists 38 islands. The 1944 Hudson's Indexed Map of Lake Minnetonka and a 1964 map made by the Hennepin County Highway department lists 23 islands. Dredging and filling of the lake's original features has created connected and obliterated islands.

STATISTICS:

The lake is made up of a number of a series of bays, points and islands with 31 interconnecting channels covering 22.2 square miles of water (14,043 acres) and 125 miles of shoreline.

The drainage extends over 123 square miles; the deepest point is Crystal Bay (101 feet). (Note: I believe the deepest point in Minnetonka is actually a 120'+ hole off of the mouth of Robinson's Bay on the main Lower Lake. PH)

11 miles long,

6 miles wide

14,310 acres of water

101 feet deep (Crystal Bay) (?)

110 miles of shoreline

Contains 15 lakes of 3 different kinds

Formed by melting ice blocks in glacial moraines 15,000 years ago

929.4 feet above sea level at the outlet, Grays Bay dam

130,340,400,000 gallons or 400,000 acre feet water capacity

10.9 miles greatest length (Halsted's Bay to Grays Bay)

30 feet average depth

April 12 - 17 is range of average ice-out dates

28 inches maximum ice thickness

20 - 24 inches average ice thickness

123 square miles is area of watershed, including Minnetonka

922.7 feet above sea level modern low water level, December 20, 1937

931.43 feet above sea level modern high water level, Sept. 12, 1951 Geo5020--Lake Minnetonka Information

The huge lake is really many different lakes biologically speaking. I've heard Freshwater Society founder DR. Richard Gray say the Lower Lake, the Upper Lake and Halstead's Bay for example all have different water clarity and composition.

The outlet for Lake Minnetonka is Minnehaha Creek which drains from Gray's Bay on the northeast side of the lake.

Minnetonka running high.

High water at Deephaven boat docks Monday. (Photo by Luke Huttner)

As I touched on this morning, high water warnings are in effect for Lake Minnetonka this spring. You must operate with minimum wake anywhere inside of 600 feet from shore to prevent erosion this spring.

High Water Emergency Declared on Lake Minnetonka
4/15/2011

"The Lake Minnetonka Conservation District (LMCD) has issued a high water declaration on Lake Minnetonka. According to LMCD Code Section 3.021, "High Water", the Executive Director shall make a "High Water Declaration" when the Lake elevation is at or above 930.0 feet for a period of eight consecutive days, or has reached or exceeded 930.25 feet. On Monday, April 11th, the Lake's elevation reached 930.29 feet. For this reason, the LMCD has initiated a "High Water Declaration", effective immediately."

http://minnetonka.waterpatrol.org/highwater.htm

Highest in 5 years!

As of Monday Lake Minnetonka is at the highest water level in 5 years! Some numbers:

930.17' Monday's lake level (above mean sea level)

+1.5 feet higher than last November

2006 last time Minnetonka was this high. (May 16th, 2006)

Boat ramps underwater. (Photo by Luke Huttner)

Minnehaha Creek is raging thanks to a discharge of 250 CFS from Gray's Bay Dam on Lake Minnetonka. The swift flow in Minnehaha Creek is considered dangerous for travel by canoe.

White Bear Lake: Northeast metro jewel

White Bear Lake in fall color.

White Bear Lake lies nestled between "desirable" residential communities in the northeast metro.

The lake is home to an active sailing club, beautiful lakefront homes, and provides numerous opportunities for boaters. White Bear also has some interesting history!

Map of White Bear Lake.

White Bear Lake History :
(From the White Bear Lake Conservation District)

This history of White Bear Lake consists of vivid characters and tales of mystery. Some interesting historical facts:

It is believed that F. Scott Fitzgerald used White Bear Lake as the backdrop for his book, Winter Dreams. The name of the town in the book is Black Bear Lake. Fitzgerald was a summer resident on the lake.

In the Prohibition Era, many gangsters came to White Bear Lake to hide out when they were in trouble. Some famous gangsters believed to come to White Bear Lake are Ma Barker, Pretty Boy Floyd and Al Capone.

White Bear Lake got its name from a Sioux Indian legend about a Sioux hunter who killed a white bear on Manitou Island and whose spirit lives on Manitou Island still. Manitou Days is a celebration in honor of the white bear's spirit.

Nine Indian mounds were located on the Northwest shores of the lake. The largest mound was located approximately where Shady Lane meets Lake Avenue. The mound was later destroyed and 17 skeletons were removed from it.

Land in the area was first available for sale in 1847 at a price of $1.25/acre. All of the land in the township was purchased by 1860.

The first settler in what is now the City of White Bear Lake was V.B. Barnum. He purchased land in 1852 between Goose and White Bear Lake. He built the first resort hotel on the lake which became the Leip House.

Manitou Island was developed in 1881 by the Manitou Implement Company and included water and sewer service.

On May 28, 1883, a committee was appointed "to act with town authorities and the different syndicates, owning property around the lake, to devise and execute measures for retaining and preserving the waters of White Bear Lake."

Ice was harvested from the lake to build the Ice Castles for the Winter Carnival years ago. Many feared that the lake would have little to no water left from the hundreds of thousands blocks of ice removed from the lake. They had nothing to fear; the lake always replenished itself.

About White Bear Lake: (Info from White Bear Lake Conservation District)

Background

"White Bear Lake has been a popular resort area since about the time of statehood. Along with Lake Minnetonka, White Bear Lake developed into a popular vacation destination, drawing visitors from hundreds of miles away. Parks, resorts, steamboats and hotels flourished in the late-1800s and early-1900s. White Bear Lake remains a popular lake for a variety of recreational uses.

THE LAKE

The Basin

White Bear Lake has a surface area of 2,590 acres and a maximum depth of 83 feet - large and deep for metro lake norms. The lake has three distinct basins: the north basin which has a maximum depth of about 30 feet and an extensive littoral area (area where rooted plants grow); the west basin which is shallow with a maximum depth of 22 feet, and the southeast basin has a maximum depth of 83 feet.

Lake Level

Because of its large surface area and its small tributary watershed, lake levels in White Bear Lake fluctuate. Fluctuations of up to 2½ feet in one year and up to 7 feet over the lake's history have been observed. The impact of lake level changes is magnified because small changes in vertical elevation result in large changes in the horizontal extent of the lakeshore. When lake level changes are extreme, many problems occur. During high water levels, flooding and shoreline erosion increase; and during low water levels, docks and piers are high and dry, navigation is hindered, and recreation is diminished."

Playing catch up:

Things were looking pretty grim last October on White Bear. The lake hit an all time record low water level on October 19th, 4 feet below average and over 6 feet bellow the all time high water level on White Bear!

Again some numbers:

919.43' record low level on White Bear last October

920.05' level as of April 19, 2011

7" rise in White Bear water level since last fall

923.42' "Average" level for White Bear

926.7' Highest level ever recorded on White Bear lake (June 20, 1943)

Slow to recover:

Even with 86" of snow last winter, White Bear Lake has been slow to recover.

While Lake Minnetonka is up about 1.5 feet from last fall, White Bear only managed to rise about 7 inches. The biggest reason is that White Bear has a much smaller watershed than Minnetonka.

Prolonged drought in the east metro hit White Bear hard over the past few years.

Let's hope the generous rains continue to fall on White Bear, so the lake can recover to normal levels in the coming years.

PH

Lake water temps hit 80 degrees

Posted at 5:00 AM on July 24, 2010 by Paul Huttner
Filed under: Lake Superior, Lakes

Lake water temps near seasonal highs:

A check of water temperatures near the Weather Lab in Lake Minnetonka this week shows a surface water temperature of 82 degrees. This is at or slightly above the peak average temperature for southern Minnesota lakes, which usually takes place from late July into mid- August.

July sunset on Lake Minnetonka. Water temperature 82 degrees.
(photo by Paul Huttner)

Even Lake Superior is showing unusually warm temps this summer with lake water temps near 70 degrees at the mouth of North Shore rivers like the Knife River.

Changes in wind direction over Lake Superior cause upwelling to bring frigid water to the surface with little warning in some areas. It is interesting to watch water temps fluctuate wildly in summer. Surface temperatures may be near 70 one day, and plunge into the 50s or even 30s in some areas with little warning. Keep that in mind if you are thinking of a dip in the big lake this summer.

What's the water temperature at your favorite lake this weekend? Please send a comment if you have a reading from one of our 10,000+ lakes.

Enjoy the "bathwater" lake temperatures for the next few weeks.

PH

Storms fade overnight

Posted at 12:00 AM on July 24, 2010 by Paul Huttner
Filed under: Lakes, Severe weather

Update 1:45am:

Storms will move rapidly east and fade overnight. A few storms storms will linger in Wisconsin and southeast Minnesota through 4am.

Update 12:50am

Bow echo passing just south of the metro with damaging winds. See warnings below.

PH

MPX: 5 Sse Cannon Falls [Goodhue Co, MN] mesonet reports TSTM WND GST of M59 MPH at 01:17 AM CDT -- measured at mndot sensor at mile post 90 on hwy 52

MPX: Mankato [Blue Earth Co, MN] law enforcement reports TSTM WND DMG at 12:14 AM CDT -- several trees down around town

MPX: Madison Lake [Blue Earth Co, MN] law enforcement reports TSTM WND DMG at 12:20 AM CDT -- tree down on powerline

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1258 AM CDT SAT JUL 24 2010

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHERN DAKOTA COUNTY IN EAST CENTRAL MINNESOTA...
WESTERN GOODHUE COUNTY IN SOUTHEAST MINNESOTA...
EASTERN RICE COUNTY IN SOUTH CENTRAL MINNESOTA...

* UNTIL 200 AM CDT

* AT 1256 AM CDT...RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS...
CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THESE
STORMS WERE LOCATED ALONG A LINE EXTENDING FROM 12 MILES WEST OF
CASTLE ROCK TO 3 MILES SOUTH OF NORTHFIELD TO 10 MILES SOUTHWEST OF
NERSTRAND...AND MOVING EAST AT 50 MPH.

LOCATIONS IN THE WARNING INCLUDE...
NORTHFIELD...
NERSTRAND...
DENNISON...
KENYON...
STANTON...
CASTLE ROCK...
RANDOLPH...
WASTEDO...
CANNON FALLS...
HADER...
WANAMINGO...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR
DAMAGING WINDS IN EXCESS OF 60 MPH. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.

Damaging winds are likely with fast moving bow echo in Nothfield, Faribault, and Owatonna.

1248 AM CDT SAT JUL 24 2010

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN
STEELE...RICE AND SOUTHWESTERN DAKOTA COUNTIES UNTIL 115 AM CDT...

AT 1246 AM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF
60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM
LONSDALE TO FARIBAULT TO DEERFIELD...MOVING EAST AT 55 MPH.

LOCATIONS IMPACTED INCLUDE...
FARIBAULT...OWATONNA...LONSDALE...MEDFORD...WEBSTER...DUNDAS...
RUSKIN...NORTHFIELD...NERSTRAND...CLINTON FALLS...BRIDGEWATER...
MERTON AND MOLAND.

Also, heavy rains will cause localized flooding south of the metro.

FLOOD ADVISORY
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1249 AM CDT SAT JUL 24 2010

MNC019-037-049-079-085-131-139-143-240900-
/O.NEW.KMPX.FA.Y.0025.100724T0549Z-100724T0900Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MCLEOD MN-CARVER MN-DAKOTA MN-SCOTT MN-SIBLEY MN-GOODHUE MN-
LE SUEUR MN-RICE MN-
1249 AM CDT SAT JUL 24 2010

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR...
DAKOTA COUNTY IN EAST CENTRAL MINNESOTA...
EAST CENTRAL MCLEOD COUNTY IN CENTRAL MINNESOTA...
EASTERN SIBLEY COUNTY IN CENTRAL MINNESOTA...
LE SUEUR COUNTY IN SOUTH CENTRAL MINNESOTA...
RICE COUNTY IN SOUTH CENTRAL MINNESOTA...
SCOTT COUNTY IN EAST CENTRAL MINNESOTA...
SOUTHERN CARVER COUNTY IN EAST CENTRAL MINNESOTA...
WESTERN GOODHUE COUNTY IN SOUTHEAST MINNESOTA...

* UNTIL 400 AM CDT

* AT 1247 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH HEAVY RAINFALL ACROSS THE ADVISORY AREA. RAINFALL
AMOUNTS OF NEAR 2 INCHES IN AN HOUR OR LESS ARE POSSIBLE AS THESE
THUNDERSTORMS MOVE ACROSS THE AREA.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE MINOR FLOODING TO
OCCUR...ESPECIALLY ALONG SMALL STREAMS AND NEAR LOW WATER
CROSSINGS. SOME LOCATIONS THAT WILL EXPERIENCE MINOR FLOODING
INCLUDE...FARIBAULT...APPLE VALLEY...ARLINGTON...BELLE PLAINE...
BURNSVILLE...CANNON FALLS...CARVER...CLEVELAND...COATES...COLOGNE...
CREDIT RIVER...DUNDAS...EAGAN...ELKO...FARMINGTON...GLENCOE...GREEN ISLE...
HADER...HAMBURG...HAMPTON...HELENA...HENDERSON...JORDAN...
KILKENNY...LAKEVILLE...LE CENTER AND LE SUEUR.

Update 12:00am Saturday (Original post 4:30pm Friday)

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1230 AM CDT SAT JUL 24 2010

MNZ060-067>070-076-240615-
CARVER-DAKOTA-HENNEPIN-LE SUEUR-SCOTT-SIBLEY-
1230 AM CDT SAT JUL 24 2010

...THUNDERSTORMS MOVING INTO CARVER...DAKOTA...HENNEPIN...LE
SUEUR...SCOTT AND SIBLEY COUNTIES THROUGH 115 AM CDT...

AT 1225 AM CDT...WEATHER SERVICE RADAR WAS TRACKING STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 3 MILES WEST OF GREEN ISLE
TO 6 MILES EAST OF LE SUEUR TO ST HENRY. THESE STORMS WERE MOVING
NORTHEAST AT 50 MPH.

WINDS UP TO 50 MPH ARE EXPECTED WITH THESE STORMS.

* LOCATIONS IN OR NEAR THE PATH OF THESE STORMS INCLUDE...
HAMBURG.
NORWOOD/YOUNG AMERICA.
WACONIA.
VICTORIA.
SHOREWOOD.
MINNETONKA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS THUNDERSTORM COULD INTENSIFY QUICKLY...SO BE READY TO ACT IF A
WARNING IS ISSUED.

A line of strong to severe storms is rumbling eastward through the southern half of Minnesota overnight. A line of severe storms will pass along the I-35 corridor south of the Twin Cities. Expect large hail and possible damaging winds of 60 mph with this line of storms.

Storm reports:

MPX: Eagle Lake [Blue Earth Co, MN] law enforcement reports TSTM WND DMG at 12:20 AM CDT -- large trees down.

A severe T-Storm Watch in in effect south of the metro until 7am.

In the Twin Cities expect a wave of thunderstorms through 3am. Most of the severe threat looks to stay south of the central metro, but storms will contain frequent lightning, downpours, gusty winds and possibly small hail as they pass through.

From Twin Cities NWS:

SHORT TERM FORECAST
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1150 PM CDT FRI JUL 23 2010

MNZ042>045-049>053-057>063-066-068>070-076>078-084-085-092-093-
240630-
ANOKA-BENTON-CARVER-CHISAGO-DAKOTA-FARIBAULT-FREEBORN-GOODHUE-
HENNEPIN-ISANTI-KANABEC-KANDIYOHI-LE SUEUR-MCLEOD-MEEKER-MILLE LACS-
MORRISON-RAMSEY-RICE-SCOTT-SHERBURNE-STEARNS-STEELE-TODD-WASECA-
WASHINGTON-WRIGHT-
INCLUDING THE CITIES OF...ALBERT LEA...CAMBRIDGE...HUTCHINSON...
MILACA...MINNEAPOLIS...OWATONNA...RED WING...ST CLOUD...ST PAUL...
STILLWATER...WILLMAR
1150 PM CDT FRI JUL 23 2010

.NOW...
AN AREA OF MODERATE TO HEAVY SHOWERS...WITH ISOLATED EMBEDDED
THUNDERSTORMS...WILL CONTINUE TO TREK EAST AT 40 MPH ACROSS
CENTRAL AND SOUTH CENTRAL MINNESOTA...INTO THE MIDNIGHT HOUR.
WIND GUSTS TO 45 MPH...AND TORRENTIAL RAINFALL...WILL BE ENCOUNTERED
WITH THE STRONGEST STORMS. RAINFALL AMOUNTS ON AVERAGE...WILL
RANGE FROM A FEW TENTHS...TO JUST OVER ONE AND ONE QUARTER INCHES
...AS THESE CELLS PASS YOUR LOCATION PRIOR TO 1 AM. MOST OF THE
ACTIVITY WILL END ACROSS CENTRAL...AND SOUTH CENTRAL MINNESOTA BY
4 AM.

-Twin Cities radar loop
-Latest severe weather warnings

PH

As you enjoy a beautifully warm and quiet summer Friday evening, keep an eye out for possible storms in southern Minnesota overnight.

There is a slight risk some of the storms could be severe in southern Minnesota, especially along the I-90 corridor.

A flash flood watch remains in effect for the I-90 corridor counties of southern Minnesota tonight, and a tornado watch has been issued for central and eastern South Dakota until 10pm.

It looks like the bulk of any severe weather should pass south of the highly populated Twin Cities, but there could be a batch of thunderstorms rolling through anytime after midnight with the best chance between 3am and 7am.

Rare quiet Weekend?

After the chance of storms overnight, we may see what has become a rarity this summer in Minnesota...a blissfully quiet weekend. Look for increasing sunshine Saturday and Sunday, with highs in the 80s.

Lake water temps near seasonal highs:

A check of water temperatures near the Weather Lab in Lake Minnetonka this week shows a surface water temperature of 82 degrees. This is at or slightly above the peak average temperature for southern Minnesota lakes, which usually takes place from late July into mid- August.

Even Lake Superior is showing unusually warm temps this summer with lake water temps near 70 degrees at the mouth of North Shore rivers like the Knife River.

Changes in wind direction over Lake Superior cause upwelling to bring frigid water to the surface with little warning in some areas. It is interesting to watch water temps fluctuate wildly in summer. Surface temperatures may be near 70 one day, and plunge into the 50s or even 30s in some areas with little warning. Keep that in mind if you are thinking of a dip in the big lake this summer.

What's the water temperature at your favorite lake this weekend? Please send a comment if you have a reading from one of our 10,000+ lakes.

Enjoy the "bathwater" lake temperatures for the next few weeks.

PH

Lake temps hit 70 degrees

Posted at 4:35 PM on May 28, 2010 by Paul Huttner
Filed under: Lakes

Jump on in the water's fine. At least in southern Minnesota.

Lake temperatures have warmed to 70 degrees in the southern half of Minnesota this Memorial Day weekend. A brief trip on to Lake Minnetonka in the weather lab skiff produced a surface water temperature of 72 degrees at several spots in Carson's Bay Friday afternoon. 70 degrees is considered to be safe swimming for most people.

Boaters enjoy an early start to the Memorial Day weekend on Carson's Bay on Lake Minnetonka Friday afternoon.

Lake temperatures are hard to come by up north (hint hint), but my estimate is that surface water temperatures range between 62 and 68 degrees on many lakes in central and northern Minnesota. This is still a little chilly, and may be a bit of a shock if you dive into your favorite lake "up north."

Our early and mild spring has given lake temperatures an early boost this year.

While temperatures may be relatively warm at the surface, the water cools rapidly with depth. At a few feet below the surface, temperatures will fall steeply in what's known as the thermocline. This rapidly cooling layer of water moves deeper as the summer progresses. Temperatures may fall from the 60s and 70s at the surface to the hypothermic 50s just 5 to 10 feet down below the surface this time of year.

Lake temperatures fall in the thermocline. The thermocline moves deeper as summer progresses.

Get out and enjoy the lakes this holiday weekend, but remember to "test the waters" before you jump into your favorite swimming hole!

Have a safe and wonderful holiday weekend.

PH