A May Record (And Not the Good Kind)

May 20, 2015: Did you know that we have had as many days in the 50’s this month as we’ve had days in the 80’s so far? Yep. Three days a piece.  That doesn’t count the 40°, record-setting weather for today.

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Today’s coldest high temperature record was 51°, set in 2002.  A high of 47° this afternoon definitely broke that record.  We ended up being 26° below average.

frz rain 1

The atmosphere was cold enough to produce ice pellets as rain added insult to the injury of the cold, May weather. The ice didn’t accumulate, but still wasn’t pleasant to see.

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For those of you wanting to have the warmer weather back, you’ll get your wish.  We will rocket into the 70’s starting tomorrow.

-Alex

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Posted under cold blast, record weather, weather

This post was written by Alex Kirchner on May 20, 2015

Record dry air (nearby)

April 14, 2015: Did the air feel really dry today to you? It did in Chicago today, where the dry air tied a record at O’Hare airport.  The relative humidity dropped to 13%, which tied April 8, 1971, April 11, 1956, and May 10, 1934 for the driest relative humidity on record for Chicago. For reference, the human body generally feels comfortable at 45% relative humidity, so 13% is very dry!

Relative humidity readings at 4 pm today

Relative humidity readings at 4 pm today

If you are wondering what or how we figure out the relative humidity of the air, here’s a crash course (get ready for a lot of science!): humidity describes how much water vapor is in the air. We can measure this with absolute humidity, which is the mass of water vapor divided by the mass of dry air at a certain temperature. The hotter the air, the more water vapor it can hold, and so the value for absolute humidity is higher.

To get to relative humidity, we use the ratio of the current absolute humidity to the highest possible absolute humidity at that temperature. At 100% relative humidity, the air is completely saturated and can’t hold any more water, usually creating rainfall as the moisture falls out of the air.

An area of high pressure results in downward movement in the atmosphere. This dries the air out, and is why we don't usually have clouds or active weather under high pressure.

An area of high pressure results in downward movement in the atmosphere. This dries the air out, and is why we don’t usually have clouds or active weather under high pressure.

Why did the air feel so dry today? We did have an area of high pressure right overhead, which may have contributed to the dry conditions. High pressure promotes downward movement in the atmosphere, which counteracts what you may have learned in elementary school about the water cycle- instead of the air rising, then cooling and condensing into clouds, downward moving air dries out.  This is one of the reasons why the air was so dry today.

-Alex

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Posted under event, record weather, science, weather

This post was written by Alex Kirchner on April 14, 2015

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

It Rained; It Poured

Scattered showers and thunderstorms pulsed up across northern Illinois and southern Wisconsin on Friday. While not everyone got wet, those who did got soaked! So much rain fell in the Forest City that Flash Flood Warnings were issued. Standing water was everywhere.

august1st

A new record was achieved in Rockford. The airport picked up 1.35 inches of rain in about two hours on August 1, 2014. This set the record for maximum daily rainfall. In other words, it has never rained so much on any August 1st since records began in 1906. The old record for maximum daily rainfall was 1.32 inches in 2000.

-Joe

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Posted under 13 Climate Authority, rain, record weather, statistics, weather

This post was written by qni_it on August 2, 2014

Cool in July

It’s official! July 2014 was the third coolest July on record in Rockford. Most of us are probably not surprised by this! After all, we only hit 90 degrees once that month. Climate history in the Forest City began in 1906. July 2014 has tied with July 1992 and July 1996 as the third coolest of all time. There have only been two other Julys cooler than this year.

july3rd

Here are the statistics! Our high temperature averaged out to 79.2 degrees which was 5.3 degrees cooler than normal. Our low temperature averaged out to 59.1 degrees, or 3.9 degrees cooler than normal. When factoring in highs and lows, July 2014 had a temperature average of 69.1 degrees. The coolest July on record occurred just five years ago in 2009, with an average temperature of 67.0 degrees. To put this into perspective, a normal July has an average temperature of 73.8 degrees.

-Joe

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Posted under 13 Climate Authority, record weather, statistics, weather

This post was written by qni_it on August 2, 2014

Chilly Mid-July Low Temperatures

Wednesday morning’s low temperatures were a bit on the chilly side! Although we are in the middle of July, temperatures bottomed out in the upper 40s and lower 50s across northern Illinois and southern Wisconsin. These kind of temperatures are what we usually expect in mid-May or mid-September!

Weds. July 16, 2014 Low Temps.

Weds. July 16, 2014 Low Temps.

Rockford did not reach a record low temperature, however. The record low for July 16th is 46 degrees from the year 1945. Rockford bottomed out at 50 this morning. It could have been worse, though. Parts of northern Wisconsin and Minnesota fell into the upper 30s!

Chilly Weds. Morning in Wisconsin

Chilly Weds. Morning in Wisconsin

The forecast for Thursday morning remains cool. Low temperatures may flirt with the record low of 49 degrees, set in 1976.

FutureTrack: Another Cool Morning Thursday

FutureTrack: Another Cool Morning Thursday

If you’re wondering when things are going to warm back up around here, check out THIS BLOG POST.

-Joe

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Posted under cold blast, FutureTrack, record weather, statistics, weather

This post was written by qni_it on July 16, 2014

Independence Day Records

Independence Day 2014 will not enter the weather record books. But that doesn’t mean we shouldn’t remember it! This year we had a mostly sunny sky with low humidity values. The day started off a bit cool with a low of 52 degrees in Rockford. During the afternoon, we warmed up to a comfortable 79 degrees. Overall, it was a pleasant holiday!

July 4th, 2014 High Temperatures

July 4th, 2014 High Temperatures

Looking back at the climate history books, only 23% of Independence Days in Rockford had a high temperature in the 70s. Most of the time—about 53%—our high is in the 80s. The coolest high temperature occurred on July 4, 1967 with a reading of only 62 degrees. It’s no surprise that July 4, 1967 also had the record cold low temperature. That was 46 degrees!

July 4th Records

July 4th Records

The hottest temperature to ever occur in the Forest City on July 4th happened just two years ago! Back in 2012, we sizzled in 102 degree heat! It has also stayed dry on the 4th of July for the last four years. In fact, about 54% of Independence Days remain dry. Since 1906, only twelve holidays have had rain totaling more than a quarter of an inch!

-Joe

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Posted under 13 Climate Authority, history, record weather, statistics, weather

This post was written by qni_it on July 4, 2014

Memorial Day Climatology

Memorial Day 2014 is upon us! What started as ‘Decoration Day’ in order to honor the graves of fallen soldiers just after the Civil War, Memorial Day was declared a national holiday in 1971. After that declaration, the holiday was observed on the last Monday of the month of May. Since the date changes from year to year, there is no statistical ‘normal’ from a climatology standpoint.

However, daily weather observations have been recorded for Rockford since 1905. Since records began, the majority (42%) of Memorial Days have had high temperatures in the 70s (41 out of 106 data years). About 26% of Memorial Days have had a high temperature in the 80s (28 out of 106 data years). This year, we’re going to be in the 80s! Last year, of course, was the 7th coolest high temperature for any Memorial Day at 61 degrees! It was also a little rainy.

Memorial Day Statistics

Memorial Day Statistics

Does it always rain on Memorial Day? A lot of people have been asking this question lately. The answer of course, is no, but it’s not a solid no. If history proves anything, we’ve got about a 50/50 shot at seeing at least some rain on Memorial Day! Since records began in Rockford, 52 Memorial Days have had rain while 55 have not! The wettest Memorial Day occurred in 1916, with 1.65 inches of rain falling in Rockford. May 28, 1984 was probably the most miserable Memorial Day from a weather standpoint: the high temperature was only 47 degrees with just over an inch of rain! This year, it looks like we’ll have to dodge some scattered showers and thunderstorms.

-Joe

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Posted under 13 Climate Authority, record weather, statistics, weather

This post was written by qni_it on May 25, 2014

Seasonal Snow Update

With a quick dusting of snow Monday night in northern Illinois and southern Wisconsin, our seasonal rank moved up a notch!  Officially 0.2 inches of snow was observed at Chicago Rockford International Airport, bringing our seasonal snow total to 56.6 inches.

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This ties us into 7th place with the snowy 2008-2009 season.  Here is a look at the top 10 snowiest seasons on record in Rockford:

  • 74.5″ —– 1978-1979
  • 72.9″ —– 2007-2008
  • 62.1″ —– 1951-1952
  • 61.0″ —– 1942-1943
  • 58.2″ —– 1974-1975
  • 56.7″ —– 1925-1926
  • 56.6″ —– 2008-2009
  • 56.6″ —– 2013-2014
  • 55.9″ —– 1911-1912
  • 55.2″ —– 1959-1960

-Joe

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Posted under 13 Climate Authority, record weather, snow, statistics, weather

This post was written by qni_it on March 25, 2014

3rd Place: Good or Bad?

SNOW. There hasn’t been a lot of “in between” this season; you either love it or hate it. Since November 11th, Rockford has witnessed 54.9 inches of snow. Little did we know that on December 8th, a record long stretch of days with snow on the ground would begin!

Since December 8th, our weather observation site at Chicago Rockford International Airport has steadily picked up 53.9 inches of snow. Thanks to record cold temperatures and a weather pattern that brought the white stuff as frequently as every other day, snow has remained on the ground for 90 days!

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We’re in record territory. December 9, 2013 through March 8, 2014 is currently the 3rd longest stretch of days with snow on the ground. This edges out an 89-day period with snow on the ground from 1977-1978.

As of March 8, 2014

As of March 8, 2014

Here are the Top 5 longest stretches of days with snow on the ground in Rockford:

  1. 107 days ending March 18, 1979
  2. 97 days ending March 18, 1962
  3. 90 days so far this season
  4. 89 days ending March 18, 1978
  5. 59 days ending February 11, 1984

With a warming trend in our forecast, our streak may soon come to an end. If we keep snow on the ground through next Saturday—which is possible—we will tie for 2nd place!

-Joe

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Posted under 13 Climate Authority, record weather, snow, statistics, weather, winter weather

This post was written by qni_it on March 8, 2014