NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
2:58 AM Saturday December 20
W2 WAVES ARE PROVIDED AS A RANGE OF SIGNIFICANT WAVE HEIGHTS, WHICH IS THE AVERAGE HEIGHT OF THE HIGHEST 1/3 OF THE WAVES, ALONG WITH THE AVERAGE HEIGHT OF THE HIGHEST 10 PERCENT OF THE WAVES WHICH WILL OCCASIONALLY BE ENCOUNTERED.W2 SYNOPSIS, A RIDGE OF SURFACE HIGH PRESSURE AVERAGING 303 INCHES STRETCHED FROM QUEBEC THROUGH THE GREAT LAKES TO THE LOWER MISSOURI AND OHIO RIVER VALLEYS THIS MORNING.W2 THIS RIDGE WILL MOVE SLOWLY EAST OF LAKE MICHIGAN THROUGH THIS AFTERNOON.W2 THE HIGH PRESSURE RIDGE WILL REMAIN ACROSS EASTERN NORTH AMERICA SUNDAY, WHILE AN AREA OF LOW PRESSURE OF 294 INCHES MOVES SOUTHEAST ALONG THE LEE OF THE NORTHERN ROCKIES.W2 THIS LOW WILL TRACK ACROSS THE NORTHERN PLAINS SUNDAY NIGHT THEN WILL SLOWLY MOVE INTO THE UPPER MISSISSIPPI VALLEY MONDAY BEFORE FILLING TO NEAR 296 INCHES ON TUESDAY.W2 WHILE THIS LOW FILLS, ANOTHER LOW WILL DEVELOP ACROSS THE LOWER OHIO OR TENNESSEE VALLEYS LATE TUESDAY, AND IS EXPECTED TO DEEPEN RAPIDLY TO NEAR 288 INCHES AS IT MOVES NORTH INTO THE GREAT LAKES REGION WEDNESDAY.W2 THIS DEEPENING LOW TRACK WOULD LIKELY PRODUCE WESTERLY GALES ON LAKE MICHIGAN LATE WEDNESDAY INTO THURSDAY.W2 LMZ261-362-364-366-563-565-567-868-201615.W2 LAKE MICHIGAN FROM SEUL CHOIX POINT TO ROCK ISLAND PASSAGE 5 NAUTICAL MILES OFFSHORE TO MID LAKE.W2 LAKE MICHIGAN SOUTH OF A LINE FROM SEUL CHOIX POINT TO THE MACKINAC BRIDGE AND NORTH OF A LINE FROM CHARLEVOIX MI TO SOUTH FOX ISLAND 5 NAUTICAL MILES OFFSHORE.W2 LAKE MICHIGAN FROM CHARLEVOIX TO POINT BETSIE MI 5 NAUTICAL MILES OFFSHORE TO MID LAKE.W2 LAKE MICHIGAN FROM POINT BETSIE TO MANISTEE MI 5 NAUTICAL MILES OFFSHORE TO MID LAKE.W2 LAKE MICHIGAN FROM ROCK ISLAND PASSAGE TO STURGEON BAY WI.W2 LAKE MICHIGAN FROM STURGEON BAY TO TWO RIVERS WI 5 NAUTICAL MILES OFFSHORE TO MID LAKE.W2 LAKE MICHIGAN FROM TWO RIVERS TO SHEBOYGAN WI 5 NAUTICAL MILES OFFSHORE TO MID LAKE.W2 LAKE MICHIGAN FROM PENTWATER TO MANISTEE MI 5 NAUTICAL MILES OFFSHORE TO MID LAKE.W2 sheboygan wi to pentwater mi north today, variable winds 5 to 10 knots early becoming south.W2 waves 1 feet or less.W2 tonight, south winds 10 to 15 knots.W2 waves 1 to 3 feet.W2 sunday, south winds 15 to 25 knots increasing to 30 knots in the afternoon.W2 chance of snow in the afternoon.W2 waves 2 to 4 feet building to 4 to 7 feet occasionally to 9 feet in the afternoon.W2 sunday night, south winds to 30 knots.W2 chance of snow.W2 waves 6 to 9 feet occasionally to 11 feet.W2 monday, south winds to 30 knots becoming southeast.W2 chance of rain and slight chance of snow in the afternoon.W2 waves 6 to 9 feet occasionally to 11 feet.W2 monday night, southeast winds to 30 knots early easing to 15 to 25 knots.W2 rain.W2 waves 5 to 8 feet occasionally to 10 feet.W2 tuesday, southeast winds 15 to 25 knots diminishing to 10 to 15 knots in the afternoon.W2 rain likely.W2 waves 4 to 7 feet occasionally to 9 feet subsiding to 4 to 6 feet occasionally to 8 feet in the afternoon.W2 wednesday, north winds 15 to 25 knots becoming northwest and increasing to 30 knots by late afternoon.W2 rain and snow likely.W2 waves 1 to 3 feet building to 4 to 6 feet occasionally to 8 feet in the afternoon.W2