March 2007 Archives

Mild moist air held over Illinois Saturday evening and tornado watches were in effect for much of northern and central Illinois, southern Wisconsin and extreme NW Indiana. By press time wind damage with gusts to 70 m.p.h. were reported in Kendall and DeKalb Counties in northeast Illinois. Two brief tornado touchdowns were sighted in SW Wisconsin. There were numerous hail and wind damage reports in Nebraska, Missouri and Iowa Saturday.

Seasonably mild readings will persist into Tuesday; however, by Tuesday night any "summery" feel to the air will most likely be history. Canadian high pressure reminiscent of January or February will force readings to plunge some 30 to 40° with Tuesday night's low temperature in the upper 30s expected to be Wednesday's high. Snow showers are in Chicago's forecast Wednesday night and Thursday with lake-effect snows possible in northern Indiana Thursday and Friday.

The weather of two seasons—late winter and late spring—is to visit Chicago Saturday and Saturday night. Mild spring air may be the last thing on Chicagoans’ minds much of Saturday, given the cool, damp winds off Lake Michigan much of the day. However, that’s just the sort of air mass expected to send temperatures noticeably higher in the city toward evening.
A northbound warm front is behind the predicted change. Its passage ushers 70s into southern suburbs by mid and late afternoon, even as readings remain mired in the upper 40s and low 50s on the Lake Michigan shoreline, especially along the North Shore communities north to Waukegan and Kenosha. As southerly winds take over behind the front this evening, moist 60° dew point air (reflecting Gulf Coast moisture levels) is to lend a decidedly more springlike feel—quite a change after a day of cool, raw winds off the lake.
The clock continues ticking toward March’s close Saturday night. The month is expected to wind up Chicago’s 14th mildest March in 137 years of official National Weather Service records.
--By Tom Skilling, WGN-TV Chief Meteorologist

Chicagoans have enjoyed 11-days of 60° or warmer temperatures this month—more than twice normal (an average of four 60s has occurred in March in the past 137 years). The 70° high predicted later Saturday pushes the 60°+ count to 12—the most here since 1946. That means this month has hosted five times the number of 60s on the books in the same period a year ago. March, 2007 moves into its final hours running nearly 5° above the long term average. It ranks among the warmest 15% of all Marches on record here—and that’s despite the recent rash of chilly days with east winds off the lake.
Friday becomes the fourth consecutive day to feature lake winds which cut into daytime highs.
The 2007 tornado season is proving formidable. With the tally of U.S. twisters closing in on 300, the country has been subjected to three times the January through March average over the past 30 years.
--By Tom Skilling, WGN-TV Chief Meteorologist

Thunderstorms, which towered up to ten miles into the atmosphere from west Texas north to South Dakota late Wednesday, unleashed dozens of twisters across sections of five states. It was one of the 2007 season’s most active outbreaks to date. The storms erupted along a meteorological feature familiar to Plains residents—the so-called dry line. It’s the demarcation between air sinking out of the Rockies (and drying in the process) and humid northbound Gulf air.
The presence of a steep vertical temperature decline and powerful, storm-spinning jet stream winds aloft set the stage for Wednesday’s violent weather.
As tornadoes raked the Plains, the same spring storm buried the Rockies under snow measured in feet from Utah north to Wyoming and Montana. Nearly 30” was down late Wednesday at Brian Head, Utah where the elevation is 9,700 ft.
--By Tom Skilling, WGN-TV Chief Meteorologist

A gusty cold frontal passage sent Chicago area temps into a nosedive Tuesday ending an impressive early season mild spell. For three consecutive days, area temperatures had surged to 73° or higher, levels more typical of June. Three days with readings at such warm levels in March is something which has happened only three times here since 1871.
The warmth has helped establish this month as the 21st warmest March of the past 137 years with a temperature averaging 41.2°—5.3° above the long term average since 1871.
Chicagoans who left jackets at home Tuesday morning were surprised by the chill which greeted them as they headed home. Readings on the lakefront at Northerly Island fell 24° between noon and 1 p.m. In Milwaukee, Kenosha, Waukegan, Grayslake, the same front sent readings diving 17° in just five minutes late Tuesday morning. Winds surged from under 5 m.p.h. to 40 m.p.h. in gusts as cold air arrived.
--By Tom Skilling, WGN-TV Chief Meteorologist

Chicagoans who headed off to work in Tuesday morning’s unseasonable warmth without a jacket or coat are in for a rude surprise when they step outdoors this afternoon. Two days of record-breaking warmth have come to a dramatic end with the passage of a powerful “back-door” cold front. The front, which had already sent readings diving 17-degrees in 5 minutes time by late this morning north of Chicago including Milwaukee, Kenosha, Waukegan, Grayslake and Highland Park—from the 60s to the 40s with 40 mph wind gusts and the onset of low clouds and fog near Lake Michigan---reached the Loop during the lunch hour. It has continued south since. Its passage produced a windshift to the northeast off a mammoth, cool Canadian high pressure and the chilly waters of Lake Michigan, initiating a 22-degree temperature pullback in the process in under an hour’s time at Northerly Island. Not until Friday night and Saturday, when warmth resurges briefly, will area residents be treated to anything close to the record breaking 79-degree highs which headlined Sunday and Monday’s weather here—and only briefly. Cooler weather hits later this weekend and longer range forecasts suggest below normal temperatures are to dominate the opening two weeks of April overall. The just-departed warm spell was the city’s earliest of that intensity in more than a decade and a half.

Interestingly, temperatures ahead of the southbound cold front Tuesday surged for a time to 80-degrees and higher in southern sections of the metro area including Oak Lawn, Peotone, Bonfield (84-degrees) and Dwight (83-degrees). A process known as “compressional warming”, involving the generation of warmth as converging winds compressed or squeezed the air mass ahead of the incoming chill (gases like the air we breath heats when compressed), was responsible for a 40-degree temperature spread across the front midday Tuesday. North suburban areas temperatures from the mid 40s to low 50s even as Chicago’s southern suburbs basked in summerlike low to mid 80s.

The chill will spread across all corners of the Chicago metro area the remainder of Tuesday afternoon as strengthening northeast winds take hold. Scattered thunderstorms have erupted along the cold front as it has pressed south into Indiana and the southernmost Chicago area toward Will, Kankakee, Kendall and LaSalle counties. More general rainfall is likely to develop later Tuesday night into Wednesday as the front stalls to Chicago’s south and is overrun by warm, moist air from the south.

Wednesday’s blustery ENE winds and extensive cloudiness will limit high temperatures to the 40s---30-degrees below the record 79-degree highs recorded in Chicago Monday and Tuesday.

Tom Skilling
Chief Meteorologist, WGN-TV

Spirits soar here each year with the arrival of the first really warm days which follow the seemingly endless chill of a long Chicago winter. The warmth of recent days has distinguished itself as being especially unusual. Of the 11,244 days with 70°-plus highs since weather observations began in 1929 at Midway Airport, only 84 have occurred any earlier. That’s less than 1 percent! Not only have each of the city’s 79° official highs the past two days established new records, Chicagoans haven’t been treated to readings as warm this early in the season since an 81° high on March 12, 1990.
Warmth wasn’t confined to Chicago: Records fell across sections of 16 states Monday—among them 72° at Duluth, Minn.; 63° at Marquette and 73° at Alpena, Mich.—noteworthy because of the proximity to 40° lake waters.
East winds shift off 43° Lake Michigan waters Tuesday, cooling and saturating warm, moist air here, producing lake fog and helping generate sporadic thunderstorms.
--By Tom Skilling, WGN-TV Chief Meteorologist

Spring exploded in the Chicago area Sunday as highs surged into the upper 70s, aided by abundant sunshine and gusty southwest winds. The warmth covered the entire metropolitan region, including the lakefront where Northerly Island peaked at 77º.
The mercury officially reached 79º at O’Hare, shattering the old 1967 record of 75º and falling just one degree shy of the 80º plateau—a rare Chicago temperature benchmark in March, reached on only 10 days since 1871 (most recently on March 12, 1990, when it hit 81º). If highs on Monday top 77º, the city could break its third record high this month, capping a dramatic temperature reversal after March’s chilly opening.
The early season warmth helped fuel severe thunderstorms across the upper Midwest, where hail and high winds battered parts of western and central Wisconsin. One-inch-diameter hail pelted areas north of Madison near Portage while strong winds downed trees east of Minneapolis.
--By Steve Kahn, WGN Weather Center Meteorologist

A developing spring storm, on a track to reach the Midwest Sunday, brought both heavy snow and twisters to Colorado Saturday. While Boulder residents were digging out from an 8"+ snowfall, several twisters were sighted less than 200 miles to the northeast near the Nebraska border.
Southerly winds ahead of the strengthening storm will send early-season warmth into the Midwest and also tap ample moisture. Severe storms are possible throughout northern Illinois Sunday, but Wisconsin appears to face the brunt of the severe weather threat. With many area streams and creeks already near or above flood stage, flooding potential here remains high.
Chicago area temps should reach the 70s both Sunday and Monday and above normal readings should continue the entire week, though a major cool-down looms as March prepares to exit next weekend.
--By Steve Kahn, WGN Weather Center Meteorologist

Fog slashed visibilities to fractions of a mile late Friday evening and continues as Saturday dawns. Its demise will be slow given the limited wind predicted Saturday, and the fact that the area is literally awash in moisture. Soils are saturated, preventing moisture from percolating below the surface; standing water is widespread, especially in southern sections where more rain fell Thursday night and Friday than typically falls in a full March; and many rivers are in flood. Though the current level of flooding is fairly modest, the onset of downpours—possible in the waves of thunderstorms predicted at times over the coming week-—could greatly aggravate the situation.
John Hazzard, who farms in Will County, says rains will have to stop for at least 10 days before spring planting can begin. Planting has started between April 18 and 28, he reports, over the past 10 years.
Rainfall Friday reached 3.41” at Muncie, Ind.; 3.13” at Chatsworth, Ill.; and 2.79” at Remington, Ind.
--By Tom Skilling, WGN-TV Chief Meteorologist

Bret from Manteno, Ill., has forwarded us this photo taken by his father off a balcony at Myrtle Beach, S.C. Bret tells us his Dad is wintering there. Thanks for the chance to more than glimpse at the sun, Bret, even if in a photo.

John Hazzard, one of our observers who farms at Wilmington, Ill., in western Will County, reports ponding water and saturated soil as the 2007 planting season approaches. He estimates 10 days of dry weather may be necessary before planting can begin. And John tells us the start of planting has occurred on average between April 18th and the 28th in the past 10 years and contrasts this season with last when subsoil moisture was precariously short after an extended spell of dry weather.
--By Tom Skilling, WGN-TV Chief Meteorologist

March 2007 has turned very wet as evidenced by river and stream flooding and saturated soils at many locations. More than 3" fell overnight in the hardest hit far south suburban locations. The ongoing flooding pictured here on Carpenter's Creek from observer Mary Anne Best of Remington, Ind., is the worst in at least 7 years. Mary Anne tells us she's seen water there only a bit higher in the 25 years she's been there. She adds:

"In the pics where you see the fencing to our internal yard and the bird feeder hanging off the fence....that is 10 feet above the level of the creek bank. There are may streets closed here in town due to high water. All of it is coming from Carpenter's Creek. The rain we got does not cause this kind of flooding. It is coming from Benton County on top of saturated ground."

Some overnight totals south of Chicago:

Muncie, IN 3.41"
Chatsworth, IL 3.13"
Remington, IN 2.79"
Bonfield (Kankakee County, IL) 1.75"
Wilmington (Will County, IL) 1.30"
Lowell, IN 1.10"

In Chicago proper, Frank Wachowski near Midway Airport reported at noon Friday that 1.45" has fallen at his location on the South Side since precipitation began Wednesday. Thanks to all for the reports and to Mary Anne for another illustrative photo set!
--By Tom Skilling, WGN-TV Chief Meteorologist

This spectacular shot of lightning arcing the length of a cumulonimbus cloud was taken by Hans Goeckner looking to the south on a flight over Tennessee back on November 10, 2002, giving us a view of lightning that we seldom see. Thanks Hans for sharing this photo with us.
—WGN-TV Weather Center

Cool high pressure pushes into northeast Illinois today—and even with the sun Tuesday, temperatures will be below normal, especially along the lakefront where readings could fail to reach 40° due to a persistent east-to-northeast wind off the cold Lake Michigan waters.
The Vernal Equinox occurs Tuesday, marking the start of astronomical spring in Chicago—and it seems that the metro area was just waiting for that event. A significant warm-up will begin Wednesday, and unseasonably mild readings are forecast the remainder of this week through next weekend. Along with the higher temperatures, showers or thunderstorms will be mentioned in the forecast almost daily.
Meanwhile, it will take a while to warm up over the extensive snow cover left in the wake of the St. Patrick’s Day storm in the Northeast, and also much of the north-central U.S. where an additional 3 to 8 inches of snow was forecast Sunday night.
--By Paul Dailey, WGN Weather Center Meteorologist

Following the Vernal Equinox on Tuesday, a return to predominantly southerly wind flow will bring another spring-like 30-degree temperature swing to the Chicago area, pushing readings temporarily back to mid-May levels Thursday and Friday accompanied by a significant increase in humidity. To start the week, a band of rain will spread over northeast Illinois later tonight and diminish Monday morning as the triggering cold front moves east. After about a 36-hour cool, dry period, a warm front Wednesday is expected to trigger an all-day rain that could feature thundery downpours. With the warm front to the north, a warm humid air mass will be in place over the area. Thursday and Friday daytime high temperatures could warm into the 70s; but with a cold front slowly approaching from the west, the amount of cloud cover and the possibility of showers or thunderstorms will influence readings considerably.
--By Paul Dailey, WGN Weather Center Meteorologist

St. Patrick’s Day is off to a cooler than usual start in Chicago. Normal March 17 highs reach 47°—but today’s readings are likely to end up nearly 10 degrees lower. Light NNE winds and more rapid than usual vertical temperature declines in the lowest mile of the atmosphere set the stage for possible lake-effect snow flurries.
However, any snowflakes here Saturday pale in comparison to the mammoth accumulations which have hit the East Coast. Going into this winter’s latest storm there, Boston had only recorded 6” of snow—just 17% of normal—while the seasonal tally in New York City as flakes began falling mid-morning Friday was 7”—only a third of normal. Wilkes-Barre/Scranton, Pa., where 60s occurred just days ago, was on its way to 12 continuous hours of heavy snowfall late Friday evening. Snowfalls could reach 30” in the hardest-hit areas of upstate New York.
In stark contrast was Phoenix, Ariz.’s record 99° Friday—its hottest reading so early in the year.
--By Tom Skilling, WGN-TV Chief Meteorologist

Snow covered the ground as Thursday dawned in northwest Indiana—a radical change from 70s only a day before. But even more jarring weather changes threaten residents out East Friday into Saturday as a rapidly intensifying late-winter storm bears down on the area. As a slushy, travel-snarling and occasionally heavy mix of snow, sleet and rain sweeps into areas from Philadelphia north to New York City and Boston, areas just west are to trade Thursday’s unseasonable 60s for a foot or more of wet snow. Wilkes-Barre/Scranton, Penn., where highs hit 67° Wednesday, could see an 11-13” snow accumulation while Albany, N.Y., with a 65° Wednesday high, appears headed for 12-16” of snow.
Chicagoans shivered through a 38° high Thursday—35 degrees off Wednesday’s record 73° at O’Hare. But, record-tying 82° warmth headlined the weather Thursday at Richmond, Va., while Myrtle Beach, S.C., hit 74°. Out West, Phoenix, Ariz., reached 92°—its second record high in a row.
--By Tom Skilling, WGN-TV Chief Meteorologist

Canadian air arrives today, abruptly ending Chicago’s brief flirtation with spring warmth. Tuesday’s temperatures surged into the 70s across the area, and records tumbled. The mercury peaked at a record-shattering 73º officially at O’Hare, thereby establishing a new record high for the day -- and it was Chicago’s highest reading in 160 days (since 76º last Oct. 4).
Unseasonable early-spring warmth, pleasant though it is, always carries the possibility of severe thunderstorms, and that risk looms for areas immediately to the south and east of the city area today as a strong cold front sweeps in.
Yesterday’s temperatures reminded us that spring is just around the corner, but yet another reminder comes from dermatologist Dr. Bryan Schultz, who informs us that yesterday’s sunshine was powerful enough to cause sunburn after 41 minutes of exposure during the early afternoon sun peak.

--By Richard Koeneman, WGN Weather Center Meteorologist

In any given winter, the coldest month of the season is invariably either December, January or February, and a computer sweep of the 136 Chicago winters (1870-71 through 2005-06) confirms it.
Most often, January is the season’s coldest month (it was the coldest month in 72 winters out of 136, or 53 percent of them); February comes in second (39 winters, or 29 percent) and December ranks third (23 winters, or 17 percent).
But that’s not the whole story. Surprisingly, March—which we consider to be a spring month—was the “winter’s” coldest month during the cold seasons of 1889-90 and 1931-32.
It certainly won’t happen again this year (February was so cold), but it is worth noting that Chicago’s winters don’t always play by the rules.
Jumping to the present, this March has another surprise in store: Temperatures surge into the 60s early this week, then crash into the teens later in the week.
--By Richard Koeneman, WGN Weather Center Meteorologist

The transition into Spring is under way with an early time change (set clocks ahead one hour today) and the end of astronomical winter now in sight (Spring Equinox is March 20). Huge swings in high temperatures are expected to occur during the week ahead with readings varying as much as 30°. Southwest winds will usher in a big warm up early in the week with high temps Sunday through Wednesday averaging well over 10° above normal. Tuesday should be the warmest day with only extensive cloudiness and a threat of showers holding readings from reaching into the 70s. A cold front will settle south and split the Chicago area Wednesday with a huge temp range from the lower 40s north of the front to perhaps the lower 70s south. Thursday should mark the changeover to cold over the entire area with highs the last two days of the week averaging better than 10° colder than normal.
--By Paul Dailey, WGN Weather Center Meteorologist

As a cold front moves east, high pressure builds into northern Illinois today. Despite northwest winds, sunny skies should allow high temperatures to reach readings nearly 5 degrees above normal. The center of high pressure is expected to drift slowly east the next few days, reaching Ohio and Pennsylvania Monday and shifting off the East Coast later Tuesday.
Southerly winds flowing up the backside of the high are forecast to intensify Monday, tapping warm air in the southern and central Plains, pushing readings toward the 60° mark as far north as Chicago. Southwesterly flow is to continue Tuesday with further warming over Illinois, but an increase in mid and high-level clouds and rain later in the day will probably keep highs from reaching 70°.
Heavy rains are expected to be confined to the Gulf Coast states as low pressure in that area restricts the northward surge of moisture.
--By Paul Dailey, WGN Weather Center Meteorologist

Chicago’s winters—even the mild ones—are long enough, cold enough and stormy enough that most of us are anxious for the arrival of spring by the time the calendar flips into March. In fact, meteorologists consider March to be the first month of spring.
And when we have endured a February as cold as the one just ended (with an average temperature of 17.9º at O’Hare Airport, it was the coldest since 1979 and the 11th coldest out of 137 on record), we’re even more anxious for the first hint of mild temperatures.
Our forecast data continues to tease us with the prospect of a significant warm-up later this week, and a 50° reading cannot be ruled out for Friday. But before that, we have to endure another round of light snow late Tuesday night into Wednesday morning, the product of a weak storm system that will sweep rapidly southeastward across the area.
--By Richard Koeneman, WGN Weather Center Meteorologist

Kevin and Laura Stupca were kind enough to share these dramatic photos of the Park Point area of Duluth in the aftermath of the two blizzards that recently swept through Minnesota. The huge snow drifts are a testament to how much snow socked the Duluth area. Thanks Kevin and Laura!
—WGN-TV Weather Center

Chicago’s long bout with late winter cold and snow may finally be showing some signs of breaking down. However, before milder conditions move in, the city will have to endure one more reinforcing shot of cold and light snow in the early part of the upcoming week. The first chink in the cold’s armor will come on Wednesday as southerly winds send highs toward the 40º mark. But the real break in the cold should arrive by Friday as expected highs reach the lower 50s bringing the city its mildest weather since New Year’s Eve.
Forty-six years ago today on March 4, 1961, Chicago’s South Side was reeling from a major tornado that raced through the area at speeds approaching 50 m.p.h. Temperatures surged into the 70s just south of the city in advance of this twister, but in typical, volatile March fashion, just four days later on March 8 heavy,wet snow blasted Chicago as a strong low pressure system passed through the Ohio Valley.

--By Steve Kahn, WGN Weather Center Meteorologist

Airborne snow riding the highest winds here in over a year Friday slashed visibilities to near zero in open areas surrounding the city. For 17 consecutive hours, wind sensors at O’Hare registered 30+ m.p.h. gusts, including a peak gust of 43 m.p.h. A 50 m.p.h. gust at Midway Airport 2:31 p.m. Friday afternoon was the site’s strongest in 14 months. The Harrison-Dever crib three miles offshore clocked gusts as high as 58 m.p.h.
While snow fell heavily enough to slash visibilities below 1/4 mile with some regularity, accumulations—challenging to determine in such a wind-whipped environment—totaled just 0.8” at Midway and 0.6” at O’Hare. It was another world to the west and north. Snow totals had reached 25” at Finland, Minn., (near Duluth) late Friday. Bayfield, Wis., registered 21.5”, and Lake Superior ice had piled into 25-foot high mounds in the howling winds at Duluth where 19.4” was tallied.
By contrast, Melbourne, Fla.’s 92° shattered a March 2 record. Other record highs occurred Friday at Vero Beach (91°) and Orlando (89°) in Florida.
--By Tom Skilling, WGN-TV Chief Meteorologist

Even though snow and high winds swept the entire Chicago metropolitan area Friday, conditions in the city were not nearly as bad as they were in more open rural areas. These spectacular blizzard pictures look like they could have been taken in North Dakota, but they were taken near Hebron, Ill., and sent to us by Robert Fesus of Round Lake.
--By Steve Kahn, WGN Weather Center Meteorologist

We get a real feel for the impact of Friday's mammoth winter storm, which has lashed the Upper Midwest with wind gusts clocked to 66 m.p.h. and snow accumulations up to 25", from these photographs relayed to us by Kevin and Laura Stupca, who live in Cloquet, Minn., about 20 miles west of Duluth. I want to share with you what they reported to us on Friday (March 2):

"These are pictures of our second blizzard (this one dumped around 2 feet) in a week – there have been only two blizzards in the last 15 years up here, both this week unfortunately! The snow is waist deep in some spots, our backyard fence is about 4 feet and the spruce tree out front is 6-7 feet high for reference. Winds blew at up to 60 knots (69 m.p.h.), and some drifts in the area are 15 feet!"

Many thanks Kevin and Laura!

--By Tom Skilling, WGN-TV Chief Meteorologist

Howling west winds—40 m.p.h. and stronger at times Friday—propel waves of snow across the area, reinstating a wintry chill in the process. Gone are the 50° highs which reached Pontiac and Gary and the 48° observed briefly at Midway Airport. Bursts of thundery rain left 1.09" at O’Hare, the most ever on a March 1 here.
Friday’s gales here are tied to the latest winter storm to rake the Heartland and fall short of the 66 m.p.h. gusts which accompanied its white-out snowfall in Duluth last evening. Minneapolis, where snow is to fall into Friday night, though at a slower pace, sat beneath 12" of snow late Thursday. In western Iowa and eastern Nebraska, where Omaha’s winds reached 57 m.p.h. Thursday, up to 16" of new snow had fallen.
The storm’s southern flank proved especially vicious, spawning at least 22 twisters. A brief touchdown was reported west of Champaign in Macon County.

March, 2007 opens with the creek pictured here in Remington, Indiana out of its banks as a result of heavy runoff on the frozen ground. Our observer there is Mary Anne Best, who shares this photo with us.

Thanks Mary Anne!

Tom Skilling

PHOTO CREDIT: Mary Anne Best