If the temperature hits 93 degrees Tuesday — as forecast — Twin Cities residents might finally celebrate the end of winter.

But if you're thinking of taking a spring-affirming leap into that shimmering blue lake, the Department of Natural Resources has a word for you: Don't. Make that Don't!

"As Minnesotans we think we're hardy, and we want to get out there and jump in the lake, but right now, it's just not safe," said Kara Owens, the DNR's boat and water safety specialist.

Only three days ago, snow and graupel — a tiny relative of hail that forms in cold weather — fell across some of the metro area, and many lakes across the southern half of Minnesota lost their cover of winter ice less than two weeks ago. Despite today's forecast high — 2 degrees short of the May 14 record — the cold soul of winter lingers in the water.

On Monday, most bays on Lake Minnetonka had a surface temperature of 46.4 degrees, said Telly Mamayek, spokeswoman for the Minnehaha Creek Watershed District. Owens said that even 70 degrees is considered cold enough to prompt a "gasp" reflex for people, which could lead to choking and drowning, not to mention cardiac arrest. The current temperatures are far more threatening.

Maybe it's a good thing, then, that the 90-type heat will soon pass. Highs through the rest of the week will fall back into the mid- to upper 70s, and into the 60s by next week.

BILL MCAULIFFE