2 in a row

February 20, 2015: The month of February has not been our friend lately when it comes to the cold. We had record-breaking weather yesterday, with more Arctic air looming in the forecast. We’ve had 3 days above the freezing point all month, with little chance to see any more days above freezing before the end of the month. The insult to our cold-related injury is that last February was just as cold!

February 2014 and currently this month rank as some of the coldest February's on record.

February 2014 and currently this month rank as some of the coldest February’s on record.

Through yesterday, we’ve had an average temperature (average of all the high and low temperatures this month) of just under 14°.  This value ranks us, so far, as the 5th coldest February on record.  Just two spots above this February sits 2014 as the 3rd coldest. After back-to-back harsh February’s, let’s hope next year we have mild end to winter, or we are going to start hating the 2nd month of the year!

-Alex

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This post was written by Alex Kirchner on February 20, 2015
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It’s Cold, but is it Record Breaking Cold?

February 19, 2015: The Stateline is no stranger to wicked cold winter temperatures, and dangerously cold morning wind chills. We’re used to layering up, warming our cars, and heading out into the bitter cold. This morning was another day to add to the list of uncomfortably cold mornings with hazardous wind chills. But could this one be one for the record books?

Turns out, it might be TWO for the record books.

Potential record number 1:
If Rockford’s high temperature stays in the single digits today, a 79 year old record will be broken. February 15-18, 1936 holds the record for Rockford’s latest consecutive days of single digit temperatures. Yesterday, Rockford hit a high temperature of 8°. If we combine yesterday with today’s forecast of single digit high temperatures, we’ve got ourselves a record of the latest occurrence of 2 or more consecutive single digit high temperatures.

2-19-15 recordbreakingcold2

 

 

 

 

 

 

 

Potential record number 2:

If Rockford’s high temperature only climbs to 6° or less, a 56 year record will be broken. On February 19th, 1959 Rockford only reached a high temperature of 7°, which is still the coldest for this date on ever recorded.

2-19-15 recordbreakingcold

 

 

 

 

 

 

 

We’re so lucky, right?

-Morgan Kolkmeyer

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Posted under cold blast, history, record weather, statistics, weather, weather geek, winter weather

This post was written by Morgan Kolkmeyer on February 19, 2015
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It’s not just us…

February 18, 2015: As we hunker down and huddle for warmth during tonight’s and tomorrow’s bitter cold, take solace in this: we aren’t alone.

Take a look at this map:

Wind chill advisories and warnings cover half the nation tonight.

Wind chill advisories and warnings cover 23 states tonight.

This shows all of the wind chill warnings and advisories in effect tonight, and nearly half the nation is impacted by the cold! The bitter air stretches from North Dakota to Florida tonight.

I got to thinking: how cold does it have to be to issue an advisory or warning for other areas in the U.S.? Here’s the rundown of all 23 states under some sort of wind chill headline.  As best as I could, I grabbed the wind chill range for each state (Remember, elevation changes can cause dramatic differences. Some spots of South Carolina have a vast difference between conditions, from +15° wind chills to -27° by simply going up into the mountains):

Alabama: 0 to -10

Arkansas: -10 to -15

Florida: +10 to +35

Georgia: -5 to +10

Illinois: -15 to -30

Indiana: -15 to -25

Iowa: -20 to -30

Kentucky: -15 to -30

Maryland/Washington, D.C.: -5 to -15

Michigan: -20 to -35

Minnesota: -30 to -40

Missouri: -10 to -20

New Jersey: -15 to -35

New York: +5 to -20

North Carolina: 0 to -15

North Dakota: -25 to -45

Ohio: +5 to -30

Pennsylvania: -10 to -25

South Carolina: 0 to + 15 (0 to -27 at higher elevations)

Tennessee: 0 to -15

Virginia: 0 to -10

West Virginia: -10 to -25

Wisconsin: -20 to -35

The wind chill ranges do not change a ton from state to state, with most locations below zero.  However, imagine living in Alabama or South Carolina and getting wind chill values below zero.  Those conditions are very harsh when you are used to milder weather!  It would be similar to Minnesota getting -30 to -40.  With Florida, who thinks to escape the cold weather of the north, only to find 20 degree weather on a night like this? You may not think to bring the winter jacket along on your vacation.  This is why there are so many advisories out, because tonight’s cold is very impactful, regardless of where you are.

-Alex

 

 

 

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This post was written by Alex Kirchner on February 18, 2015
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Harsh Wind Chill Values

February 17, 2015: With more bitter Arctic air coming in, temperatures will be near record territory Wednesday and Thursday.  During this time, wind chill values will be hazardous, dropping well below zero.

Tonight and tomorrow feature harsh wind chill values.

Tonight and tomorrow feature harsh wind chill values.

Hazardous wind chill values are possible Wednesday night into Thursday

Hazardous wind chill values are possible Wednesday night into Thursday

Remember, make sure to cover all exposed skin, and wear extra layers, just like you have with the previous cold waves this winter. This will protect you from frostbite and hypothermia.

The records for coldest temperatures on February 19th

The records for coldest temperatures on February 19th

We typically do not see air this cold this late in February, so it is fairly likely that the coldest high temperature record could fall on Thursday, and we’ll be close to the record low that morning.

Upper level temperature forecast by the European forecast model for next Tuesday. Another surge of Arctic air is possible.

Upper level temperature forecast by the European forecast model for next Tuesday. Another surge of Arctic air is possible.

For those weary of the cold, brace yourselves: we could have another shot of extreme cold next week. This is the European forecast model, which is showing another bitter blast by next Tuesday. Hopefully, this particular solution does not verify, otherwise we may see more of these single digit days next week.  This will bear watching as we get closer to next week.

For now, stay warm! The next few days will be extremely frigid.

-Alex

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This post was written by Alex Kirchner on February 17, 2015
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The (Cold) Week Ahead

February 16, 2015: Coming off of a brisk weekend, it would’ve been nice to have some milder weather to look forward to as we stare down the barrel of a new, long week. Instead, the weather will be getting even colder as we progress through this week.

The polar jet stream dives way down into the Gulf Coast states, allowing harsh Arctic air to descend into the Midwest

The polar jet stream dives way down into the Gulf Coast states, allowing harsh Arctic air to descend into the Midwest

A new surge of Arctic air arrives by Wednesday, with the worst of the cold lasting from Wednesday through Thursday.

The outlook for the rest of the week. At times, temperatures will be 20 to 30 degrees colder than average

The outlook for the rest of the week. At times, temperatures will be 20 to 30 degrees colder than average

This is the breakdown of how far off of average we’ll be over the rest of the week.  At times, we’ll be around 30 degrees below average!

The tally of above, near, and below average temperatures so far this month

The tally of above, near, and below average temperatures so far this month

The latest plunge of polar air adds to the overall coolness that February has had. We’ve had just 2 days with above average weather, and the month is past the halfway point. Stay warm!

-Alex

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This post was written by Alex Kirchner on February 16, 2015
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Chilly Valentine’s Day

February 14, 2015: Valentine’s Day 2015 could be one of the coldest, thanks to a second punch of Arctic air flooding the Stateline this weekend.

Climatology for Valentine's Day in Rockford

Climatology for Valentine’s Day in Rockford

For reference, February 14th typically has a high in the low 30’s, with lows in the upper teens. From time to time, however, we get days like what’s ahead for the 2015 version of the holiday.

Forecast for Valentine's Day, 2015

Forecast for Valentine’s Day, 2015

Temperatures will steadily drop throughout the day, falling to the single digits by the afternoon.  We likely won’t set any records for the high temperature; the high for the day will be close to midnight, which is when temperatures are still near the 20’s as the mercury is starting its descent.

Top 5 coldest Valentine's Days in Rockford (data courtesy National Weather Service)

Top 5 coldest Valentine’s Days in Rockford (data courtesy National Weather Service)

Even in the 20’s, we’d be within the top 5 for coldest Valentine’s Days.  We haven’t had much luck lately for the holiday- last year was the 4th coldest on record.

Wind and wind chill forecast for Valentine's Day, 2015

Wind and wind chill forecast for Valentine’s Day, 2015

The temperature alone will be frigid; with winds gusting up to 40 mph, the wind chill will plummet to the 20’s below zero, making the evening pretty unbearable to be outside.  Have the extra layers handy before heading to dinner!  Have a great Valentine’s Day!

-Alex

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This post was written by Alex Kirchner on February 13, 2015
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Disappearing Snow

February 11, 2015: Last Friday, the official snow depth for Rockford (measured at the Rockford airport) was measured at 12″.  Heading into today, the depth is down to half that value.

The temperature and snow depth trend from February 6th to the 10th.

The temperature and snow depth trend from February 6th to the 10th.

The above freezing temperatures over the weekend went a long way to melt off some of the snow. That is the primary reason for losing plenty of snow pack. The difference between this weekend’s melting and ones previous this winter is the added influence of a higher sun angle and the increase in daylight.  This is why we were able to melt 6″  of snow in roughly 3 days rather than taking more time than that.

Changing the sun's angle to the ground changes the intensity of the sun's energy on the ground.

Changing the sun’s angle to the ground changes the intensity of the sun’s energy on the ground.

In the heart of the winter, the sun is low on the horizon, so the sun’s energy is coming in at an angle, and isn’t all that intense. The daytime hours are also very short, so there isn’t much time to provide a lot of energy.

Now, the sun is higher in the sky, so the sun’s energy is more directed at the ground rather than at an angle to the side. Because the energy is more directed at the ground, the energy can be more intense, helping heat the ground or snow up quicker. The longer days means more energy being put into the atmosphere.

-Alex

 

 

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This post was written by Alex Kirchner on February 11, 2015
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Will we lose a lot of snow this weekend?

February 6th, 2015: We are now almost a week removed from last weekend’s blizzard, and the snow depth remained unchanged this week, with much of the ground around the Stateline covered by a foot of snow. With the prospect of above freezing temperatures this weekend, will the snow depth change dramatically?

Earlier this winter, we had a string of snowy days that amount to a snow depth of 6″ by mid-January. A streak of milder weather set in at that point, and between the mild temperatures and at least partial sunshine, we were able to melt off all of the snow within about a week.

The change in snow depth from earlier this winter. The top portion shows the high temperature each day plus the average amount of cloud cover, with the bottom columns showing the snow depth at the end of each day.

The change in snow depth from earlier this winter. The top portion shows the high temperature each day plus the average amount of cloud cover, with the bottom columns showing the snow depth at the end of each day.

This graphic illustrates that there is a decent amount of energy that has to go into our environment to melt off that amount of snow. We lost an inch of snow per day between the 15th and the 19th, but that was because we had temperatures above freezing each afternoon plus some sunshine each day, and it still took 5 days to melt off all of the snow.

In our current case, we have double the amount of snow, and the forecast in the sunshine department doesn’t look too promising.  We should be able to see our snow depth numbers go down a little over the weekend, but it will take a good stretch of mild day coupled with sunshine, like earlier this winter, before it all goes away.

-Alex

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This post was written by Alex Kirchner on February 6, 2015
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Feb. 1 Blizzard and Snow Ratios

February 4, 2015: The Feb. 1, 2015 blizzard was interesting in a lot of ways, one being how the nature of the snow changed.  The snow started out as wet and heavy, meaning it had a higher water content, making it easier to “pack” for snowballs, but more difficult to shovel and move because of the extra water weighing it down. About halfway through the storm, the snow changed over to being more “light and fluffy”, or that grainy type of snow that can blow and drift easily.  So what happened?

First, let’s start with this: warm air can hold much more moisture than cold air.  This is why, in the summer, we deal with a lot more humidity or moisture in the air, versus the winter, when we feel the air dry out our skin, because there’s barely any moisture at all in the air and it sucks the moisture away from us.

In the winter, we have varying levels of cold all the time, so if cold air can’t hold much moisture, why do we keep getting snow? It’s because snow doesn’t need as much water to form versus raindrops; as a result, a fraction of an inch of liquid can go a long way.  This is where we start talking about snow ratios, or how much liquid it takes to produce a certain mount of snow.

Comparing wet,heavy snow to dry, fluffy snow

Comparing wet,heavy snow to dry, fluffy snow

With regards to the Feb. 1 blizzard, the air started out warmer, which kept the snow ratios lower, closer to 10:1.  That means if we had 1″ of water, it would produce 10″ of snow. The wet and heavy snow fell for a while, until the blizzard pulled in colder air from the north. That sparked the transition toward lighter and fluffier snow. At that point, the snow ratios were closer to between 25:1 to 30:1.  As you can see, the drier, colder air can produce a lot more snow with the same amount of water. At this point, the winds started really picking up, so the blizzard conditions set in since the lighter snow could cause whiteout conditions more easily.  If we had more of the cold air earlier in the storm, we could have seen the snowfall amounts grow even higher.

-Alex

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This post was written by Alex Kirchner on February 4, 2015
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Comparing Blizzards

February 3, 2015: Interestingly enough, the blizzard this past weekend happened at nearly the same time as a memorable blizzard 4 years ago. In 2011, snow started on the evening of Jan. 31, with the heaviest snow occurring on Feb. 1, followed by the storm wrapping up on Feb. 2. The 2015 version also started on the 31st, but wrapped up earlier, by the evening of the 1st.

Comparing the 2011 Feb. 1 blizzard to the 2015 Feb. 1 blizzard

Comparing the 2011 Feb. 1 blizzard to the 2015 Feb. 1 blizzard

The 2011 storm was definitely the stronger of the two, with higher wind gusts and another 3″ of snow. The 2011 version also ranks higher on the lists for worst snow storms (3rd worst compared to 2015 ranking as 10th worst).  If you compare the days, however, when both storms did most of their work, the blizzards are pretty close to each other:

Comparing Feb. 1, 2011 to Feb. 1, 2015

Comparing Feb. 1, 2011 to Feb. 1, 2015

The 2011 blizzard just nudges out the 2015 version, but we basically had the same conditions. It is eerie how the blizzards hit the Stateline on the same dates, and in nearly similar fashion.

-Alex

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This post was written by Alex Kirchner on February 3, 2015
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