Wednesday Weather Update

A deep low pressure system has already dumped snow in Colorado and western Nebraska, as well as brought high wind gusts, and is now currently in Kansas. An area of storms has already developed in the colder area just ahead of it. Dew points are already rising into the 50's ahead of the low pressure, in Iowa and Missouri. This narrow band of moisture will move northeast later this evening. With increasing moisture and a strong focused jet in the Iowa/Missouri area, instability is                                                                                                       
growing. Because this area has increasing instability, along with high wind shear, and higher amounts of available energy, it has a much higher threat for strong to severe storms. This is also the area already highlighted in orange indicating an enhanced risk for strong storms, as well as a Tornado Watch in effect until 6pm in the yellow highlighted area on the second map in Iowa and Missouri. Later today, storms will form and start off as strong individual cells (which are more capable of producing tornadoes) before they then congeal into a line where then straight line winds become more of a concern.

For the Stateline, the entire area is under a slight risk for strong storms. Our biggest threat is strong straight line winds and heavy rain fall. The tornado threat is non-zero, but it is low, with better dynamics and timing featured to the southwest of the Stateline. Areas to the west and south of Rockford do have a slightly higher threat for stronger winds as well, near the Polo, Dixon, and Sterling areas. We will mostly see strong straight line winds come through with a line of showers and a few embedded storms. Even if you don't hear thunder or see lightning, very strong wind gusts are still possible. The timing for the rain comes in around sunset, with the rain crossing the Mississippi around 5/6pm and then will move closer to the Rockford area around 7/8pm this evening. These showers will be very fast movers, and will track from the southwest to the northeast tonight. While the rain won't last long into Thursday, the wind will.



A Wind Advisory will go into effect at 6pm this evening and will last through 6pm Thursday evening.
Wednesday afternoon: Winds will pick up from the southeast and gust at 35-40mph.
By Wednesday night: Wind gusts will continue from the southeast, but will be higher at 40-45mph.
Thursday morning: Winds will shift to the west and have to potential to gust around 45-50mph, and higher at times!
Driving will be difficult on north/south roads Thursday morning, so you will want to use a lot of caution, especially if you are in a high profile vehicle.

Friday will continue to be a windy day, with a chilly northerly wind at 35 mph. As a secondary low pressure moves through, winds will make the high temperatures in the 40's feel like the 30's for most of the day. Some snow flurries will also be possible Friday morning.

Make sure to keep checking back for more updates, and tune in tonight at 5pm and 6pm with Chief Meteorologist Candice King!

'Gales of November Came Early': The Sinking of the S.S. Edmund Fitzgerald 40 Years Ago Today

November 10th, 1975 the S.S. Edmund Fitzgerald took its final voyage on Lake Superior.  Still to this day, considered the largest shipwreck on the Great Lakes.  It's believed the 729 foot vessel broke apart in the gales of November.  29 men lost their lives that day.

For more on the ship, and the weather that ultimately ended its voyage, click here.

Weather Update (Video Included)

Good Tuesday evening!  What another beautiful day in Northern Illinois and Southern Wisconsin.  Highs this afternoon reached the lower to middle 50's once again, after another frosty morning. 

I wanted to try something different on the blog - we've done this before in the past.  Below you'll find a video update regarding the thunderstorm threat for Northern Illinois and Southern Wisconsin.  Let me know you're thoughts, and if this is something you'd like us to continue.

Severe Threat Shifts Northward

We've been posting and updating the past few days as more information comes together on a potent low pressure system that will bring rain and strong winds on Veteran's Day.

Many of the forecast details have stayed the same, though there have been some slight changes. The strong low pressure system will eject out of Colorado into the Great Plains on Wednesday. As the low pressure approaches Missouri, along with very strong winds aloft, storms will begin to fire up along the low pressure's cold front. The orange shade that you see includes portions of Missouri, southern Iowa, and western and southern portions of Illinois. This is the area where all of the thunderstorm 'ingredients' gel the most. This area has the greatest CAPE or energy for the storms to tap into, shear (winds changing direction with height), moisture, and lift. Because of all of these things coming together stronger storms are likely in this areas. Biggest concerns will be hail, damaging winds, heavy rain, and even a couple of isolated tornadoes are possible.

However, all of these ingredients are not in place for the Stateline area. Moisture values won't be as high across northern Illinois and southern Wisconsin. Also, with storms arriving in the evening for us, we don't get the peak heating of the sun, which we need to generate more instability. There should be just enough instability to hear some rumbles of thunder, though the bigger threat we will be watching for will be very strong winds gusts. As showers, and a few thunderstorms move through late Wednesday, winds have the potential to reach strong, and possibly severe levels. Gusting upwards of 50mph in the storm system; though outside the heavy rain, strong winds will also be possible. Winds Wednesday night will gust close to 35-40mph. Any rain and storms we see will quickly move to the north east. Showers will be possible through early Thursday morning as the low pressure departs with the cold front. However, despite the lack of rain, wind gusts will still be strong behind the cold front. Winds will gust upwards of 45mph Thursday morning. Currently there are no wind advisories in place for the Stateline, though there very well could be. Driving at times in the morning will be difficult, especially on N-S roads.

The First Warn Weather Team has been tracking this system, and will continue to track and update you on this system as more information becomes available. Be sure to check back for more updates!

Strong Winds of Change Blow in Wednesday Night

Get ready, because it's going to get pretty windy by the middle of this week.  Departing low pressure will pull a very strong cold front through Wednesday night, causing winds to increase from the south Wednesday to the west by Thursday morning.

As the front passes, the threat for rain will end but west winds will quickly ramp up.  Wind gusts approaching 35-40 mph will occur overnight Wednesday, with gusts nearing 45 mph by Thursday morning.

This will make travel difficult on North/South roads and cause any loose items outside to blow around.  So if Thursday is your garbage day, you may have to chase your garbage cans down the roads.  We'll hold on to the breeze through Friday as cold air sets in.  Highs will only reach the low 40's.

Enhanced Risk for Severe Storms Midweek

As stated in the previous post, a potent fall storm is in the works for mid-week. The forecast is still on track for a low pressure system to move inland from the Pacific and track across the Rockies today. The low will deepen on the eastern side of the Rockies Tuesday, and then will eject into the plains Wednesday morning and afternoon.

The Storm Prediction Center has already issued an Enhanced Risk for strong to severe storms Wednesday afternoon including Kansas City, Mo, St. Louis, Mo, and Springfield, Il. A Slight Risk is issued as far north as the Quad Cities and Peoria. This area is highlighted for the greatest severe potential because of the position of the jet stream. With the exit region of the jet stream in this area, it brings strong diffluence( or divergence), strong mid-level lapse rates, and strong shear (winds changing direction with height). All of these are ingredients needed for strong storms. Biggest threats for those areas will be damaging wind gusts, hail, and isolated tornadoes.

Closer to the Stateline, the set up is different. The warm front will stay south of us through Wednesday afternoon. This will keep the storm potential down because we won't have as much moisture or lift to work with in peak storm hours. With limited energy and moisture to work with, Northern Illinois and Southern Wisconsin will mainly see rain showers, though some rumbles of thunder are possible. We look to pick up about a half inch to an inch of rainfall when its all said and done Thursday morning, though one thing we will keep an eye on is going to be the wind. Late Wednesday into Thursday winds will gust up to, and even over 40 mph, as there will be a large difference in pressure, and a big change in temperatures. These create strong gradients which translate to high winds. Wind whipped rain showers will be a concern Wednesday late afternoon and overnight, and is something we will continue to track.

Midweek Storm to Bring Rain, Storms and Wind to the Midwest

Two storm systems will impact the Great Lakes this week.  The first arrives Monday afternoon and evening, having very little influence on our weather.  The second, and stronger, system will have a much larger impact on the weather in Northern Illinois and Southern Wisconsin.

Let's first talk about the first system:  Low pressure in the Southern Plains.  An upper level low spins through Kansas and Oklahoma Sunday evening with very little reflection at the surface.  This low will move northeast into Illinois, Indiana and Ohio by Tuesday morning.  But because our atmosphere is very dry, we will likely only see an increase in cloud cover by Monday afternoon.  Any rain that does fall with this low should remain east towards Indiana and Ohio.

The second, and larger, storm system currently sits off the coast of the Pacific Northwest.  This storm will have a greater impact on a larger portion of the country.  Bringing snow out west and potentially severe weather as close as the Quad Cities and Peoria Wednesday afternoon.

As surface low pressure develops east of the Rockies Monday and Tuesday, gulf moisture will be pulled northward into the Central and Southern Plains.  This gulf moisture will interact with very strong winds in the jet stream likely producing thunderstorms, some severe, from Nebraska, Kansas, Missouri and Iowa Tuesday afternoon and evening.  Between Tuesday and Thursday, that low pressure will quickly intensify as it lifts northeast from the Plains into Wisconsin by Thursday morning.

This will draw the gulf moisture even further north by Wednesday evening into Illinois, and possibly southern Wisconsin.  Rain will begin to fall by Wednesday afternoon with thunderstorms possible Wednesday evening.  With such strong dynamics in the jet stream and strong winds both aloft and at the surface, strong to severe thunderstorms can't be ruled out for Central and Southern Illinois Wednesday afternoon.  We could even have a few stronger storm in Northern Illinois by Wednesday evening.  Something the First Warn Weather Team will be watching very closely the next couple of days!  The

Storm Prediction Center
Day 4 Outlook

Storm Prediction Center is already highlighting Central and Southern Illinois as an area of interest Wednesday afternoon.

The warm front associated with the low will lift north through Rockford Wednesday night, keeping temperatures very mild into the wee hours of Thursday morning.  A cold front will be quick to pass, however, Thursday morning bringing temperatures down into the 40's by Thursday afternoon.

Surface winds will also increase significantly Wednesday night and Thursday morning with wind gusts possibly reaching 40mph.  A second shot of cold air slides down Friday morning with highs Friday afternoon not making it much past the low 40's.  There could even be a few showers Friday morning!