Monday, January 23, 2017

Warm Stretch Continues

We've been talking about how warm its been this January, and in the previous post you can see how much warmer than average it's been this month. Through the end of last week and this weekend, we've had a long stretch of mild days.

Since January 19th, temperatures in Rockford have made it to or warmer than 40°. With today's forecast in the low 40's this would make five consecutive days at or above 40°. For Rockford, the last time that happened in the month of January was four years ago,  the 7th-12th in 2013.

Another piece of good news, the sun sets tonight at 5pm. Spring is only 56 days away!

Sunday, January 22, 2017

Gloomy, but warm, January Days

If you've been feeling a little down the past two weeks, there is a good chance the weather has something to do with it.  The sunshine Saturday was an absolute treat, but the Mother Nature was quick to bring back the fog and cloud cover Sunday afternoon.  Although the clouds did break up just in time to create a beautiful sunset!

Fog sets back in tonight with temperatures falling into the low to mid 30's.  It shouldn't be as dense as it has been the past couple of nights because of our northwest wind.  But Monday looks to be at least another mostly cloudy afternoon.

Over the past two weeks, skies have been either cloudy or mostly cloudy.  There have been days where we have seen the sun, but it was either quick to hide back behind the clouds or came out too late for us to enjoy.

Despite the cloudy days, temperatures have been running well above average.  Our monthly average highs are four degrees above what the monthly temperature average should be!  Our above average afternoons likely have a lot to do with just how warm our overnight lows have been.  We've seen very little snowfall this month and with no snow to help keep the ground cool, overnight lows have not cooled off like they normally do during this time of the winter season.

An upcoming pattern change does bring a 'cooler' pattern by the middle to end of the week.  But it's cooler to us because we're used to the warmth.  Temperatures will actually be more seasonable for the end of January. 

If you're looking for any accumulating snowfall with this temperature change, you're going to have to keep looking.  Right now it only looks like a few flurries or very light snow showers are possible later in the week.

Warm Saturday Afternoon

It sure was nice to see the sunshine Saturday afternoon.  Unfortunately, it didn't shine bright for everyone.  High temperatures where the sun did shine reached the low to mid 50's!  And it sure did feel nice.

Saturday's high of 55 degrees did fall short of the record high of 60 degrees set back in 1906.  Either way it was nice to get a little extra Vitamin D, especially considering how cloudy it has been this month.  Skies will remain mostly cloudy through Monday, but we may be able to see some sun Tuesday before our next weather system moves into the Great Lakes.

Friday, January 20, 2017

Warm Pattern Doesn't Last - Winter Makes a Return

Temperatures the past week and a half have been, for the most part, running above average.  And the warm trend continues through the weekend and into early next week.  But there are some signs pointing to a pattern change that will bring a return of the winter chill.

A series of low pressure systems will move through the Midwest and Great Lakes over the weekend.  Light rain will occur with a warm front late Friday night and into Saturday, but for the remainder of the weekend most of the rain stays south and east.  Winds will shift around to the north during the day Sunday and Monday.  Highs will continue to range roughly ten degrees above average early next week, but a stronger low pressure system will develop over the central Plains late Monday and early Tuesday.

This low will track northeast from Kansas to Missouri and into northern Illinois late Tuesday night and early Wednesday morning.  Rain showers are likely ahead of the low, but depending on how fast cooler air wraps in behind the low and the track of the low, a rain/snow mix is possible during the day Wednesday.

Following that, a strong low will develop over the Great Lakes and northeast keeping several waves of energy rotating into Wisconsin and Illinois.  With temperatures falling around 30 degrees and then into the upper 20's by the end the next week, the chance will increase for light snow rather than light rain showers.

Dense Fog Creates Dangerous Driving Conditions Friday

A Dense Fog Advisory has been issued for all of northern Illinois and southern Wisconsin Friday evening through Saturday morning.  Visibility has quickly fallen Friday evening, with some locations only reporting a few hundred feet.

With this type of dense fog, driving can become difficult as we lose daylight.  Please use caution if you're heading out this evening or very early Saturday morning.  A warm front lifting into northern Illinois later tonight with allow a few showers to develop and that may help visibility during the overnight.  But where the precipitation remains just drizzle the dense fog will continue.

Winds will increase once the warm front passes Saturday and this should help visibility improve.  Skies will remain mostly cloudy Saturday, but temperatures will warm close to 50 degrees.

Thursday, January 19, 2017

Ice Jams Occurring on Local Rivers

The recent cold snap allowed ice to quickly form on local rivers.  But the warm up has caused the ice to break apart and travel down river.  Unfortunately, ice jams have been developing along the Rock and Pecatonica Rivers causing flooding in a few communities.  Ice jam flooding is different than heavy rain flooding.  It's more localized and occurs with very little warning.

A Flood Advisory is in effect for the Pecatonica River at Shirland and for the Rock River at Dixon.  An Areal Flood Warning has been issued for the Rock River near the Ogle/Lee County line near Grand Detour, IL.  Ice spotters have reported ice jams with flooding occurring Thursday afternoon.

This picture is of the ice on the Rock River in Grand Detour.  If you look closely at the tree line, you can see just how high the river has gone.  The rainfall Thursday evening won't be anything like what we experienced on Monday, but the added rain won't help.  Scattered showers will continue on and off through the weekend, but totals should remain light.

The river gauge in Bryon is quite interesting to look at.  Notice how the river level rises Monday due to the heavy rain, but then quickly drops and then rises again.  For a time the river did reach minor flood stage, with homes being reported flooded south of Byron.  The rapid rise and fall of the river level (assuming it's not malfunctioning) is likely due to ice jamming.  The ice jam causes the water to back up upstream and slow down.  Once that jam breaks apart, the river water is flowing again - until another ice jam occurs.  This is why ice jams occur with little warning and residents along the rivers need to keep a watchful eye on river levels.

No Break For Area Rivers

It's been a soggy January so far, not with snow, but with rain. We talked earlier that the Rockford area broke a record for daily rainfall on Monday, receiving a little over an inch.

With recent rain and ice jamming, local area rivers have been rising. There are currently a few river flood advisories across the area that we will need to keep an eye on, with even more rain coming.

Rain will be arriving late this afternoon from the south and will be lifting north, starting at about 4pm. One item of note is the position of the jet stream in the upper atmosphere, oriented from southwest to northeast. Its originating in central Mexico, which is its pulling warmth but also moisture to northern Illinois and southern Wisconsin. This is bringing a lot of moisture to the area for the month January, rain totals for the area will reach around .25" to .50" but locally higher amounts are possible in any embedded storms we have tonight.

We can't forget though, that we're still in the dead of winter, and our ground is still frozen. This will allow for a lot of runoff concerns and localized flooding or ponding. Temperatures will be continuing to warm, so we really don't have a freezing concern through the weekend. There will be a few showers that will be possible Friday night and through the weekend, but they don't really amount to much. Next week, the next system passes south of us on Monday.