Increasing Rain and Wind

(9:53:52 AM) nwsbot: MKX: 3 E Sheboygan [Lmz643 Co, WI] public reports WATER SPOUT at 09:27 AM CDT -- waterspout observed offshore east of sheboygan.


9:52:26 AM) nwsbot: MKX: 5 Ene Oostburg [Lmz643 Co, WI] public reports WATER SPOUT at 09:20 AM CDT -- public report of waterspout off the coast between oostburg and sheboygan.


A Wind Advisory has been issued for both McHenry and Walworth counties that will go into effect later this afternoon and last through Thursday morning.

A band of rain continues to move in from the east this morning as low pressure lifts north through the lower Ohio River Valley.  Stuck under the cloud cover for the day temperatures won't rise much past the middle and upper 40s this afternoon.   As the low moves into Ohio and Indiana today winds will gust from the north/northeast as highs as 45 mph at times, especially later in the day and evening.  Showers will increase in intensity and coverage this evening and overnight with the heaviest of the rain being found to our east.  While the rain will likely be ongoing Thursday morning the showers should begin to end from west to east early in the day as the low moves into the northest.  As it does so, the winds will ease some but it will still be a fairly windy and cold afternoon.

Why all the wind?

A very powerfull fall storm is beginning to take shape this morning as strong winds within the jetstream push it all the way down to the south.  At the surface, this causes an area of low pressure to rapidly develop...which is occuring in the lower Ohio River Valley this morning.  This low will lift north late this afternoon and evening reaching its peak intensity overnight/early Thursday morning.  At the same time high pressure will move in from Canada across the northern Plains and the difference in pressure, known as a pressure gradient, will be fairly large: from a 995mb low this morning to a 1026mb high in the Plains.  Now wind gusts this morning are approaching 25-30mph but those gusts are expected to increase later today as the low moves closer and the high settles into the Midwest.  That's why we could have gusts here nearing 45mph, however, closer to the center of the low those gusts could approach 60mph near Chicago and northwest Indiana!  High Wind Warnings, Lake Shore Flood Warnings, Gale Warnings and Storm Warnings have been issued for locations along the shores of Lake Michigan.  Once the low begins to weaken and move further northeast late Thursday the pressure gradient will relax some helping to calm our winds.  But until then it's going to be a cold and blustery Wednesday and Thursday.