Sunday morning flood warning update

The following flood watch was issued this morning by the U.S. National Weather Service for the Eastern Upper Peninsula and Northern Lower Michigan. FLOOD WATCH REMAINS IN EFFECT THROUGH MONDAY AFTERNOON.

RECENT HEAVY SNOWFALL AND COLD WEATHER HAVE FORMED ICE ON AREA RIVERS AND STREAMS.

MILD TEMPERATURES SATURDAY AFTERNOON IN THE MID 30S, COMBINED WITH SIMILAR OR EVEN WARMER READINGS EXPECTED TODAY, WILL PROLONG THE THREAT OF ICE JAMS ACROSS NORTHERN MICHIGAN INTO THE DAY ON MONDAY.

IMPACTS: ICE JAMS ARE VERY UNPREDICTABLE AND CAN BREAK UP, MOVE AND JAM AGAIN VERY QUICKLY.

WATER BACKING UP BEHIND THE JAM CAN FLOOD AREAS UNDER DEEP WATER WITH SURPRISING SPEED, AND ANY QUICK BREAKUP OF THE JAM CAN ALLOW FOR A LARGE VOLUME OF WATER TO QUICKLY FLOW DOWNSTREAM.

FAVORED ICE JAM LOCATIONS ARE WHERE A RIVER OR STREAM BENDS OR SLOWS, AT BRIDGE ABUTMENTS OR NEAR ISLANDS, SANDBARS AND OTHER OBSTRUCTIONS TO FLOW.

AT THIS TIME THERE EXISTS TWO MAIN AREAS OF CONCERN WITH KNOWN ICE JAMMING.

THE FIRST IS ALONG THE MANISTEE RIVER NEAR SHERMAN, WITH THE OTHER ON THE AU SABLE RIVER NEAR MCKINLEY.

AREA RIVER GAUGES SUGGEST WATER HAS BACKED UP SIGNIFICANTLY BEHIND THESE ICE JAMS WITH DOWNSTREAM LOCATIONS EXPERIENCING A NOTICEABLE DROP IN WATER LEVELS.

VARIOUS OTHER RIVER GAGES SUGGEST ADDITIONAL ICE JAMS MAY BE DEVELOPING ACROSS NORTHERN MICHIGAN AND THOSE ALONG WATERWAYS SHOULD REMAIN ALERT FOR QUICKLY CHANGING WATER LEVELS THE NEXT FEW DAYS.

PRECAUTIONARY/PREPAREDNESS ACTIONS.

A FLOOD WATCH MEANS THERE IS A POTENTIAL FOR FLOODING BASED ON CURRENT FORECASTS.

PLEASE MONITOR LATER FORECASTS AND BE ALERT FOR POSSIBLE FLOOD WARNINGS.

THOSE LIVING IN AREAS PRONE TO FLOODING SHOULD BE PREPARED TO TAKE ACTION SHOULD FLOODING DEVELOP.

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