Another Active Severe Weather Season?

More than 1,700 tornadoes touched-down across the US last year. This was the second-most tornadoes reported in a single year behind 2004. A La Nina and warmer-than-normal Gulf of Mexico water contributed to the active 2011 season.

In 2012 La Nina is still in place -- although it is weaker than last year's. Still, a more active than normal jet stream across the nation's midsection is expected due to La Nina. The Gulf of Mexico is also warmer than normal. This could lead to higher evaporation rates, and more powerful thunderstorms in return.

In my opinion, below average snow cover across the northern tier of the US into Canada could be a limiting factor to severe weather. This could mean cold fronts coming in from the north will be less powerful. Still, there are more signals for an active severe season than a slow one.

For more on this topic, here's an article from accuweather.com.

Quiet today - a little more like winter tonight

The clouds you see outside are in advance of an approaching low pressure system that will be joining us later tonight and early Tuesday morning.  

Quiet weather is expected this afternoon as a breezy southeast wind bumps temperatures into the lower 40s.  By this evening, mostly cloudy skies will be found with a few light rain showers; possibly mixing with a little snow around midnight.  After midnight, temperatures may cool enough at the surface (lows will fall into the lower 30s) and there may be enough dynamical cooling aloft that a change over to snow showers will be found through Tuesday morning.  If the precipitation does change over to all snow some locations could receive up to two inches by Tuesday morning's commute making roadways, sidewalks and parking a little slick.  The low will quickly move to the east by Tuesday evening leaving mostly cloudy skies and gusty west/southwest winds in its wake.  Temperatures will rise close to 40° during the afternoon and then remain in the lower 40s through Thursday. 

Mild Winter - Little Ice on the Great Lakes

Temperatures reached the 40s once again this weekend making it 36 days since meteorological winter began (December 1st) that we've recorded 40° or higher - putting us in the top ten of number of days that have reached 40°.  The latest March outlook from the Climate Prediction Center highlights the month with above average temperatures for a good portion of the U.S. (the Stateline included) and above average precipitation.

What's even more interesting is that the mild weather has allowed very little ice to form on the Great Lakes this season.  This image is a visible satellite image of the Great Lakes taken late morning Sunday.  Notice Lake Superior where you would typically see at least some ice along the shores - very little ice is found.  The white coloring you see over the eastern portion of the lake is actually cloud cover.  Same thing across the eastern Lakes.  Almost all of Lake Michigan is open for business and water temperatures remain in the low to mid 30s.  If this view were expanded back to include more of the Midwest and Plains you would also find very little snow cover!  To me, I think this is amazing and goes to show just how mild this winter has been.

The 40° weather will continue for the next couple of days, but by the end of the week we'll tap a little into the Canadian air which will drop our temperatures back near average, if not slightly below. 

Good Weather For President's Day

A large area of high pressure is centered just off to our east.  Skies will be mostly clear tonight, with just high thin cirrus moving in from the west later on tonight, and winds will be light with temperatures dropping off to near 20 degrees by daybreak. It will be mostly sunny in the morning on Monday as the high shifts further off to the east. The winds will pick up, and become breezy from the south to southeast at 10 to 20 mph by the mid day hours. It will become partly cloudy in the afternoon as a low pressure system over the plains begins to pull moisture into the mid west, and the high temperature will reach the middle 40's. The system will move into the area on Monday night. Some scattered light rain showers or sprinkles may develop before midnight. Colder air will move in after midnight, and light snow will develop, but little accumulation is expected. The low temperature will be in the low 30's. There could be some lingering light snow in the morning. With temperatures rising into the low 40's in the afternoon, any persistent precipitation will change over to scattered light rain showers.  It will be partly cloudy on Tuesday night with a low around 30 degrees. A series of disturbances will move quickly across the area from mid and late week. The next one could cause some widely scattered light rain showers on Wednesday. There could be some rain and snow mixed on Wednesday night and Thursday. It will get a little colder, and there will be a chance of light snow on Thursday night and Friday. Little if any accumulation is expected. Saturday will be partly cloudy with a high around 34 degrees, and Sunday will be mostly cloudy with temperatures recovering to near 40 by afternoon.

Another Fabulous Day on the Way!

High pressure will move slowly across Wisconsin overnight.  Skies will be clear, and winds light. The overnight low will be near 20 degrees, although a little colder than it has been, that is a bit above average for this time of year. The average low for tonight is 19 degrees. Ordinarily it would be colder, but the lack of snow cover does not allow temperatures to fall as low as they usually would. On Sunday, with the high pressure just to the northeast of the Stateline, and with the ridge of high pressure right across the area, skies will be sunny again. The winds will be light, and the afternoon high will be close to 40 degrees.  It will remain clear on Sunday night with temperatures dropping to near 24 degrees.   On Monday the high pressure will be east of the area over Ohio in the early morning.  Skies will start off sunny, but will become partly cloudy in the afternoon as the high pressure moves to Virginia.  A good southerly breeze will develop by afternoon with an area of low pressure emerging from the Rockies, and moving out on to the plains.  Temperatures will reach the middle 40's, and could easily get higher by mid to late afternoon.  The system will move into the mid west on Monday night.  Temperatures will hold up around 32 degrees overnight.  There could be some light rain before midnight, and there will be a good chance of some sleet and snow after midnight that will linger into Tuesday morning.  Tuesday will be mostly cloudy with an afternoon high in the low 40's.  Another system could cause a light wintry mix on Wednesday as it swings across the area.  The unsettled weather pattern will continue Thursday, and with colder weather on Friday there could be a little light snow.  Even colder weather will move in from the north on Saturday giving the Stateline it's first below average temperatures for the whole week.

Severe weather season is right around the corner

As this 'winter that never really was' begins to wind down, it's time to start thinking about this upcoming severe weather season.  It's that time of year again where the surrounding National Weather Service offices will hold their annual Severe Weather Spotter classes.

Weather spotters play such an important role when severe weather, and winter weather, threaten.  Your eyes and ears are the ground truth as to what's going on!  Not only do the meteorologists at the NWS rely on your reports, but we do too!  During the class you'll talk about how to remain safe when storms threaten, the difference between a wall cloud and shelf cloud, what types of reports are useful, funnel cloud versus tornado, basic thunderstorm structure, etc.  It's a wonderful time - free of charge- and you gain a lot of valuable information!

Here's a listing of the classes divided by which county is covered by which National Weather Service office:
Southern Wisconsin (Rock, Green and Walworth counties)
North-central/north-east Illinois (Winnebago, Boone, McHenry, Ogle, Lee and DeKalb counties)
Northwest Illinois (Stephenson, Jo Daviess, Carroll and Whiteside counties)

Storms in the south block moisture further north

A weak upper level disturbance will keep the cloud cover in and out today with only a slight chance of a passing shower later this afternoon.  Once that passes Canadian high pressure moves into the Midwest and while it will bring a slight cool down temperatures will still remain above average; highs will be in the upper 30s

Further south a developing low pressure system will move through the Gulf states and into the southeast by Saturday night.  This brings the threat for heavy rainfall along with the potential for severe weather - especially Saturday.  The low is in the 'developing stages' today so a few storms may fire across Texas and Louisiana this afternoon.  As the low moves east it will gain a little more support from the upper levels as a cold pocket of air aloft interacts with the warm, moist surface.  The greatest threat for severe weather exists from far southern Louisiana, Mississippi, Alabama and the Florida panhandle.  This could also bring heavy snow to parts of the Mid-Atlantic by Sunday.  Despite our southerly winds this afternoon moisture will remain confined to the south due to the developing low.