Saturday, January 30, 2010

Lake effect as far west as Rockford?!?

When I woke up this morning I think my jaw just about hit the floor!  It's snowing!!  When I was putting together my forecast Friday morning, I figured Chicago along with some suburbs would probably have the best chance for getting in on the light snow and we would just see the spill off of cloud cover from that. (Which I even mentioned during the morning) And to some degree that was true.  The area high pressure that brought us sunshine Friday is more off to the north and with the southern storm system moving through the southeastern states, winds have taken more of a east/northeast direction causing dew points to rise allowing the snow to make it as far west as Rockford.  It shouldn't amount to much but it sure is a surprise when you look out the window.  Don't worry, we will see the sun by this afternoon. For the latest radar trends click here

Friday, January 29, 2010

What goes into making a forecast?

Do you ever wonder how a meteorologist puts together a forecast?  Or do you think we all just have a big dart board in the weather center and however good our aim is will determine what the weather will be like?  :)

A good forecaster knows that you can't always rely on what the weather computer models tell you.  You have to understand what's going on not only at the surface, but also in the upper levels of the atmosphere.  One of the things we're taught in school is to use the forecast funnel.  Look at the big picture; where are the long wave troughs and ridges, how will it evolve over time and how will this affect what's going on at the surface.  The funnel on the left represents the different scales of the atmosphere: Hemispheric, Synoptic and Mesoscale.  The funnel on the right represents the amount of time you should spend on each.  In the hemispheric scale, we want to look at the overall jetstream pattern and how it will evolve.  The synoptic scale represents the weather producing features; fronts, low pressure, high pressure, etc.  Finally, the mesoscale represnts the processes that are going on closer to the surface - usually 2 to 2,000 km ( is there going to be any dry/moist air moving into my forecast area - cold/warm air, current radar trends, etc). 

One of the things a forecaster wants to do is compare a current analysis- surface, mid and upper, to how well the computer models initalized.  Weather computer models are simulations of the atmosphere.  They use current weather observations as a starting part, such as data from upper air balloons (launched twice a day), surface observations and many, many mathmatically equations, then project the state of the atmosphere in the future.  The problem that forecasters run into is that sometimes models don't initialize very well and unfortunately that will skew the forecast.  Once we've identified whether or not the models have initialized well we then will begin our forecast by looking to see how the jetstream and weather systems will evolve through time.  At times, weather computer models will give a different end result and it's up to forecast to determine which models perform the best given the current situation or use a consensus of them all.  (That's why the further out a forecast is, 5-7 days, the more likely it is going to change)

Another thing forecasters rely on are conceptual models, experience and past weather recognition.  If we see a similar weather pattern begin to set up as one in the past, we begin to ask ourselves what kind of weather did it produce, what was the precipitation or how much did we receive.  From there we can begin to identify if something similar will happen.

Overall, there is a lot of work that goes into putting a forecast together.  A good forecaster will do a hand analysis, compare it to the weather computer models and identify if the weather pattern is similar to one from the past that produced a significant weather event.

Thursday, January 28, 2010

Haiti Telethon

If you're going to be out and about today, make sure you stop by the CherryVale mall to help donate with the Haiti Relief Efforts.  All local media outlets are taking part in a fundraiser to help the earthquake victims along with several organizations such as The Red Cross, The United Way, Hope for Haitians, The Salvation Army and Kids Around the World.  If it's too cold for you to get out you can always call: 815-332-9212 to donate, or click here. You have until 7pm tonight.

Okay...Who turned off the heat?

Temperatures this morning are starting off in the low single digits and with breezy north, northwesterly winds - wind chills have fallen well below zero.  Temperatures upstream are much colder so with a north wind expected for today, we are not advecting (or bringing) in any warmer weather.  As a result, highs will only reach about 12° for this afternoon.  That's 16° below average!  Make sure you dress in layers today, tonight and tomorrow! - Candice

Wednesday, January 27, 2010

Temperatures Tumble

We have been pretty lucky the past two weeks with temperatures at or above average.  Our average high for mid to late January is 27° to 28°.  Yesterday's high made it to 23°, which is just the beginning of the colder weather that is to come.  Look for highs today only around 20° and then low to mid teens to round out the week!  Bottom line - keep the long johns by the bedside!

Baby...It's Cold Outside!

Thanks to clear skies overnight temperatures have fallen back into the single digits this morning.  With a west, southwest wind between 5 to 10 mph, wind chills have fallen below freezing.  With such a cold start this morning and increasing clouds this afternoon high temperatures aren't expected to make it much past the 20° mark.  With a developing storm system to the south and an upper level disturbance moving through look for a few light snow showers today.  Accumulations won't be much - 1" to 2" at most!
Under partly cloudy skies tonight lows will dip back into the single digits with highs on Thursday only reaching the low to mid teens!  Yikes!  Wind chills will remain below freezing for much of the day!

Monday, January 25, 2010

Snow and Wind

Winds continue to gust close to 40 mph this evening.  That combined with the snow may cause some slick spots on roads, especially bridges and overpasses.  Strong winds will continue through tonight and Tuesday morning with wind chills nearing zero degrees.  Use caution this evening and tomorrow morning!

Rain to Snow

11:30am Update:  Snow is now beginning to fall in the Rockford Metro area.  Expect snow flurries/showers to continue on and off throughout the afternoon and into the evening. 


After a weekend of rain - snow is back in the forecast.  Thankfully for today it shouldn't amount to a lot.  Maybe just enough to make things a little slick.  We're sandwiched between two areas of low pressure this morning - one that will move through northern Illinois later today and another that will move just to the north.  With the mild weather gone just like our rain, temperatures this afternoon will fall back into the mid 20s.  Thermal profiles throughout the atmosphere are all below freezing so anything that does fall will be in the form of snow.  We're not looking at anything too significant - maybe 1"-2" by the time Tuesday morning rolls around.  The first shot will come with the low that's just off to the west in Iowa.  The second will come as the main upper low spins to the northeast.  Behind this system, however, winds will really begin to pick up for the afternoon.  We'll see west/southwest winds through today before switching to northwest by tonight.  Gusts could near 30-35 MPH!  A few flurries will linger Tuesday morning but you'll notice a difference when you step outside.  Highs Tuesday and Wednesday will be in the 20s with highs Thursday and Friday only in the teens!!  Yikes!

Sunday, January 24, 2010

Canada is Opening Up Again

The weather pattern is in the process of changing from mild to cold.  The area of low pressure that caused generous January rains last night is over Lake Superior, and remains very intense at it slows it northeast movement.  The strong circulation around the low associated with it's tight pressure gradient will cause very windy conditions across the Stateline for the next couple of days.  A disturbance riding southeast out of the Dakotas may spread some patchy light snow into northern Illinois by daybreak.  Light snow is likely Monday and Monday night before ending as flurries on Tuesday morning. Accumulations will be light... in the 1" to just less than ...2"range, but will be enough to make the roads slippery once again.  It will be windy on Monday and Tuesday with westerly winds gradually becoming more northwesterly running between 15 to 30 mph with gusts to 35 or more.  You will notice the cold with the strong winds and temperatures on Monday taking the wind chills down to the 5 to 10 above range.  Actual temperatures will get colder as the week goes on so that by the end of the week highs will only be in the teens, and lows will be zero to 5 above.
There is a positive aspect here, though.... we will actually get to see some sunshine this week. 
by Eric Nefstead

Friday, January 22, 2010

Rain this Weekend

Friday will be our quiet day, although it will be a cloudy one.  High pressure will build across the area Friday afternoon and then quickly move off to the east ahead of our next storm system.  As the low moves across the Plains, moisture from the Gulf of Mexico will begin to stream into the Midwest.  Clouds will start the day on Saturday and rain will move in west to east during the afternoon hours.  There could be a few light showers during the morning hours, but the bulk of it will come during the afternoon as the cold front nears.  Rainfall totals could range anywhere between a quarter of an inch to three quarters inch with some of the heaviest rain.  There may be a few left over showers Sunday morning - but a dry slot in the upper levels of the atmosphere could dry us out Sunday afternoon.  Once the northwest winds begin, temperatures will fall slowly throughout the afternoon and snow showers will be likely Sunday evening and into Monday.  With persistant northwest flow through next week - we'll keep the mainly cloudy skies and snow flurry chances until midweek. - CK

Wednesday, January 20, 2010

Continuing Threat of Icing Overnight

A FREEZING RAIN ADVISORY continues for the overnight hours for all of north central Illinois and northwestern Illinois until 6 am Thursday, and for south central Wisconsin until noon on Thursday.  Good lift and a moderate low level southerly jet continue tonight to produce scattered freezing rain showers and widespread freezing drizzle at 10:30 pm.  Only light amounts of precipitation were recorded for the past 6 hours across nothern Illinois.  Most main roads are in good driving condition, but sidewalks and parking lots are very slippery.  Exercise due caution to avoid falling injuries.  The precipitation will continue in a scattered fashion overnight as temps fall a couple of degrees into the upper 20's.  Slippery conditions could become more widespread by the morning rush hour.  Be prepared to allow a little extra time getting to work on Thursday morning.  Another disturbance will roll though the area on Thursday continuing the chances of light freezing rain and freezing drizzle.  .....Eric....

Freezing Rain on the Way

1:00pm Update:  Watching the radar trends this afternoon and it's interesting to see how our temperature is rising towards the freezing mark: 32 degrees.  While there is still a warm layer aloft (1500 ft to 3000 ft) it's not as pronounced as it has been the past couple of days.  This may actually allow a little more sleet to mix in with the freezing rain.  Even in Iowa there were reports of the freezing rain changing over to sleet - then back to freezing rain.  Temperatures will be important to watch over the next several hours!  It still looks like the heaviest of the precipitation is hugging either side of the Mississippi River.

11:35am: Sleet and freezing rain beginning to move into our far southwestern counties.  We'll begin to see freezing rain, possibly mixed with sleet or snow, begin this afternoon.  If we do see a little more sleet mix in - that could actually be a good thing.  The sleet would hopefully add a little more traction to the roads.

10:25am: We are beginning to receive early school closings in the newsroom: click here for the latest info.  Be sure to refresh your web page.

9:08am: Starting to see some sleet beginning to mix in with the freezing rain in Iowa right now.  Slick conditions are still being reported.  Looks like we'll start to see the freezing rain/sleet move in after the noon hour.

8:10am Update:  Reports are beginning to come in from east central Iowa this morning where between a tenth and a quarter of an inch of freezing rain has already fallen with the heavier bands of precipitation.

7:30am: Freezing Rain Advisories have been issued for all of northern Illinois and for Green county in southern Wisconsin.  Watching the radars this morning, it looks like the heaviest of the freezing rain is stretching through central/east central Iowa and west central Illinois.  The leading edge of the precipitation is just moving over the Mississippi River towards Jo Daviess, Carroll and Whiteside counties.  That will continue to move northeast throughout the morning.  We'll start to see light freezing rain fall during the afternoon and continue into the overnight.  This may even mix in with sleet and snow.  Ice Storm Warnings have been issued for central Iowa - that's where they could see the heaviest of the freezing rain.  For us, look for roads to become slick during the late afternoon/evening hours.  We could pick up around a tenth of an inch by Thursday.  Some areas, especially west/southwest, could pick up some higher amounts.  Bottom line - travel could become hazardous for your commute home.  Take it easy on the roadways.  Of course, be sure to check back for the latest updates! - Candice

Tuesday, January 19, 2010

What Happened Today?

Weather likes to do what is has been doing, a persistence is a pretty good rule to go by when things do not seem to budge.  The low level inversion was around for the last several days trapping surface moisture, and causing a low deck of stubborn stratus clouds.  There was just enough cooling at night with temperatures in the 20's to reach the dew point, and dense fog formed with light winds easing across the area resulting in hoar frost, or as the weather service now calls freezing fog.  Today, a little bubble of high pressure moved to near Lone Rock Wisconsin.  There was enough subsidence and a pool of lower dew point air with the high to scour out the inversion allowing the January sun to finally display itself, and all it's brillance.  Don't get too excited about the sunshine.  It will not be repeated on Wednesday.  There is a surface low over Oklahoma moving toward the east/northeast, and it will be over southern Missouri by 6 am on Wednesday.  Moisture will be thrown northward over a stationary from stretching eastward across southern Missouri, and up the Ohio River Valley.  It will be warm enough aloft for precipitation to be liquid, and that will fall into the cold air over northern Illinois and freeze when it touches the surface.  So, a FREEZING RAIN ADVISORY has been issued by the National Weather Service out of the Quad Cities for Stephenson County beginning at 6 am on Wednesday extending until 6 am on Thursday.  Our region can expect freezing rain to develop over  parts of Whiteside County by 6 am and spread to the northeast reaching the Greater Rockford area by the noon hour on Wednesday.  Be aware that freezing rain situations are among the most dangerous of all winter weather when driving a vehicle.  Roads could become treacherous on Wednesday afternoon across the north central part of Illinois.  Candice will have more infomation on this system on Wednesday morning... Eric

Freezing Rain Advisory

***The National Weather Service in the Quad Cities has issued a Freezing Rain Advisory for the counties of Stephenson, Jo Daviess, Carroll and Whiteside from 6 am Wednesday to 6 am Thursday***

Freezing rain combined with sleet will begin Wednesday morning south of highway 20 and begin to move northward as warm, moist air flows over cooler, drier air at the surface.  Ice accumulations of up a quarter of an inch are possible in some areas.  This will cause the morning and evening commute to become hazardous through Thursday morning.  Power outages will also be a possibility if we see more ice accumulation.  Keep checking back to get the latest information on this upcoming storm.

Upcoming Spotter Training Classes

I know it's hard to think about spring weather when we've still got snow on the ground but the Chicago National Weather Service has put out their Severe Weather Spotter Training schedule.  Click on:  Spotter Training  for more information.

Monday, January 18, 2010

Freezing Fog Pictures

A big "Thank You" to Jenn Walker for sending us this picture of a "frosted tree" Sunday morning!  It really is amazing to see pictures like this one!  Thankfully this frost doesn't have the same effect as freezing rain!  Remember - if you have any weather photos you would like to share, just send us an email!!

Dense and Freezing Fog Once Again

Freezing Fog and Dense Fog Advisories are once again in effect for Northern Illinois and Southern Wisconsin until noon today.  Watch for slick spots on the roads as temperatures are starting off below freezing.  The fog will slowly lift this afternoon but the clouds will stick around.  Temperatures will stay in the low 30s.  Fog will be possible once again tonight with lows in the 20s.  Our next big weather maker will move in midweek which could actually bring us a rain/freezing rain mix Wednesday night and into Thursday. - Candice

Calling all Viewers!

Your pictures are needed!  If you took your camera out Sunday morning to capture the freezing fog - we would love to see them!!  Send them in to: or and we'll get them on-air for you! - Candice

Sunday, January 17, 2010

Dense and Freezing Fog





Friday, January 15, 2010

Foggy and Cloudy Start to the Weekend!

With low level moisture trapped in the atmosphere, clouds will be hard to clear out this afternoon.  North winds should allow some drier air to move in but the clouds will stick around through a good part of the day.  Fog will be possible once again tonight and Saturday night.  High temperatures through the weekend will stay in the middle 30s.  Temperatures will remain above average for the next 7 days, but we are looking for a change in the jetstream pattern the middle of next week which will bring us our next chance for rain Wednesday and Thursday. - Candice

Thursday, January 14, 2010

Hello Stateline!

Good Morning!
Welcome to the First Warn Weather Team weather blog!!  We are very happy to add this feature for you because not only will it allow us to get a little more in depth with the weather, we will also be able to give you continuous coverage should severe weather threaten the Stateline.  We hope you find this blog a useful and educational tool and look forward to hearing from you soon!

Thanks again for stopping by!  Have a great day! - Candice