EXPLAINER: May 2009 Archives

Just wait, and the weather will change over the metro area today. A cold
front will move through northeast Illinois preceded by showers and
thunderstorms. Strong storms with localized heavy downpours will pass to the
north this morning, and then a more organized band of showers and
thunderstorms should develop along the frontal boundary as it moves south
through the area this afternoon. Behind the front, winds shift to the
northeast bringing much cooler air off the 50-degree surface of Lake
Michigan. Further to the south ahead of the front, strong, possibly severe
storms will develop in moisture-laden 80-degree air.

More rain Tuesday

The cold front will become stationary south of Interstate 80 Tuesday with
resultant showers and thunderstorms likely to produce additional heavy rains
and possible flooding over northern Illinois. A slight shift in the jet
stream should move this weather system well to the south Wednesday, allowing
a drying-out period the rest of the workweek. Showers and thunderstorms may
return to the Midwest this weekend.

Frost and freeze warnings in the Northeastern U.S. tonight

A very cool Canadian-source high pressure air mass will sit over the northeast tonight. With clearing skies and light winds, a late season frost/freeze is expected over a large portion of the northeastern U.S. as temperatures are forecast to drop into the lower 30s early Monday morning from Maine to northern Pennsylvania.

High pressure over northeast Illinois Sunday will give mostly sunny skies,
scattered fair-weather cumulus clouds and mild temperatures. However, events
should change rapidly as clouds thicken overnight with the approach of a
cold front. As the front moves through Monday, warming will occur along with
showers and thunderstorms. Severe storms are possible later in the afternoon
and evening. Behind the front, northeast winds off Lake Michigan will bring
a sharp 10 to 20-degree temperature drop.

Widespread heavy rains possible

As the cold front slows and becomes nearly stationary just a little south of
I-80, atmospheric conditions will be ripe for heavy, potentially flooding
rains north of the front, if repetitive thunderstorms track over the same
areas Monday night and Tuesday.

The southern edge of cool Canadian high pressure should hold over the
Midwest and Great Lakes the remainder of the workweek ,however computer
models indicate low pressure will spread rain back into this area this
coming Saturday.

There will be no repeat Saturday of Friday afternoon's lakeside temperature plunge that saw Wrigleyville readings drop to 55 degrees from 72 from noon to 2 p.m. That's because northwest winds will blow with sufficient strength to overcome the easterly lake breezes behind Friday's cooling.
Northwest winds aloft carried a showery disturbance over parts of the area late Friday. The thunderstorms that erupted with that system waited until passing the Chicago area to erupt. Cloud tops hit 43,000 feet in central Illinois.
Spotty showers will greet Chicagoans with a second disturbance Saturday morning, and a third wave may set off an isolated thunderstorm late Saturday.
Most of the weekend will remain dry.

Storms ahead
A strong cold front will move through northeast Illinois on Monday, triggering thunderstorms that may become severe in the afternoon to evening hours. Widespread rains between 1 and 2 inches are possible Monday night into Tuesday.

The 13th and final weekend of meteorological spring is likely to be the season's warmest. And half of the season's copious rainfall -- 6.78 inches of the 14.02 measured at O'Hare International Airport since March 1 -- has occurred during the past 12 weekends.
After a series of cloudy days reduced temperatures in the Chicago area, the return of sunshine will boost readings Friday substantially. A light wind regime means daytime heating could encourage the cooler, denser air that hugs Lake Michigan's surface to ride into shoreline areas as a lake breeze Friday afternoon.

Think May's been cold? Last May was cooler

Chicagoans may be surprised to hear that May, which ends Sunday night, is actually running a bit warmer than normal. The month's 59.6-degree average temperature is 1.7 degrees above the 138 year long-term average and a full 5 degrees ahead of the same period a year ago.

It's not that rainfall has occurred more frequently than usual since March 1. (The three-month March-through-May meteorological spring period receives an average of 49 days of rain in the 139 years of official Chicago weather records dating back to 1871.) But this spring's 44 days of rain to date have actually fallen five days short of the long-term benchmark.

 But when is has rained here, rainfalls have been impressive. And that's led to one of this city's wettest springs on record. O'Hare International Airport's 14.01 inches of rain since March 1 ranks as the fifth wettest of the past 139 years. But Midway's 17.04 inches exceeds any March 1 to May 28 period since records began at the Southwest Side airport in 1928.

With the clock ticking on 2009's meteorological spring season-only four days remain until its close at midnight Sunday-many Chicagoans wonder if the wet spring offers clues on the summer ahead.
Weather records indicate a modest tendency toward a cooler and wetter than normal and wetter than normal meteorological summer period.

Flooding downpours hit sections of the Chicago area with clusters of
slow-moving thunderstorms late Tuesday. Radar scans indicated cloud tops
over 40,000-feet tall.

   The weather system responsible was the same one that flooded sections
of Florida with more two feet of rain last week. Its northward jog
across Illinois generated 10.50 inches of rain in Downstate
Edwardsville, northeast of St. Louis, on Monday.

  By late Tuesday, rainfall totals in the Chicago area had passed 2.50
inches at Joliet with more than 2 inches measured in Plainfield and more
than 1 inch at Oak Brook and Midway Airport.

Wet spring at Midway

  The recent downpours have helped push the rainfall tally since March 1
(the start of meteorological spring) to more than 16 inches at the
Southwest Side site, wettest of any such period on record since 1928.

The same humid tropical air responsible for more than 2 feet of rain and waves of thunderstorms across sections of Florida last week has made its way to Chicago.
That this air mass is of tropical origin isn't immediately apparent because of winds off a still chilly Lake Michigan, but its moisture content is bountiful. Nearly 2 inches of water is evaporated in a column of air over Chicago -- moisture that is available to be swept into the concentrated downpours of thunderstorms expected to build this afternoon and evening as daytime warming takes place. Converging surface winds along a northbound warm front threaten to enhance the upward motion of air later in the day and into the night. Further complicating the potential for heavy rains are the light winds stacked high in the atmosphere above Chicago. At jet stream levels -- from 18,000 to 40,000 feet where winds can reach 80 m.p.h. or more this time of year -- winds Tuesday should hover near 20 m.p.h. This will slow the forward movement of any thunderstorms that erupt, prolonging downpours at the hardest-hit locations.

Gathering clouds and winds off chilly Lake Michigan will suppress temperatures Monday, keeping readings mainly in the 60s with areas along the immediate lakefront hard-pressed to break 60 degrees. In 2004, it reached 66 degrees.

Most of this holiday should be dry, but showers could reach southern parts of the Chicago area by nightfall. It's all downhill from there as a sluggish low pressure system takes up residence across the Midwest, bringing the city a rainy period that could last into Thursday. This system brought upward of 2 feet of rain to Florida last week and continues to produce impressive rainfall totals. The Little Rock area received more than 2 inches of rain Sunday, and nearly 3 inches doused Lake Charles, La. Flash flooding occurred in northeast Arkansas, and twisters were sighted in northwest Tennessee and southeast Missouri.

Twister hit 113 years ago
On May 25, 1896, an F3 tornado did considerable damage as it cut a 4.5-mile path from Park Ridge to Niles. Areas in Edison Park and Norwood Park were hit hard.

Chicago's brief respite from cool, wet weather is over as a storm system
that drenched Florida with upward of two feet of rain the past few days
takes aim at the Midwest. Cloudiness will begin to roll in late Sunday,
setting the stage for a prolonged cool, wet period that will last into
Thursday as the storm works its way into the Midwest via a trek through  the
Gulf States and the Missouri and Mississippi Valleys. During this period,
temperatures in the city and near the lake will be hard-pressed to get out
of the 60s as clouds, rain and winds off the lake all combine to promote the
cool conditions.

City could get a soaking

This storm continues to produce heavy rain and the Chicago area could see
significant totals midweek. West Palm Beach, Florida was inundated by a
daily record 5.33 inches Saturday while Daytona Beach logged 2.56 inches.
Flash flood watches are posted for portions of Mississippi and Arkansas for
up to four inches of rain. The storm also spawned a possible twister in east
central Alabama at Halawaka Creek Saturday damaging docks and overturning
several boats.

Rain isn't completely out the picture Saturday, but dry hours will
outnumber any wet ones. Saturday afternoon's air is to hold 1.25 inches
of evaporated water and the day's initially light winds are unlikely to
flood the area with cool, stabilizing air off the lake.

With mixed sunshine predicted and a slightly faster than usual vertical
decline in temperature -- a condition which encourages air to rise and
cool, thereby producing clouds -- the potential exists for scattered shower
and thunderstorm development. Computer models are predicting a column of
the atmosphere above Chicago may grow saturated later Saturday with
moisture to an altitude of more than 30,000 feet, suggesting vertical
clouds capable of producing some thunderstorms.
 
Winds converging along a weak southeast-bound front may further
encourage precipitation development, though peak areal coverage isn't
likely to exceed 20 to 30 percent of the metropolitan area.

Lake winds strengthen Sunday, sweeping modestly cooler, drier air across
the area and reducing the chance of rain.

Three consecutive days of 80s-the longest warm spell in the Chicago area
since last September-come to an end. Northeast winds and noticeably
cooler temperatures greet area residents as Friday gets under way.

A southbound cold front swept in around 8 p.m. Thursday bringing an end
to the warmth that included a second 84-degree high at O'Hare
International Airport and an 85-degree peak reading at Midway Airport
earlier in the day. The influx of cool air saturated the lower
atmosphere with moisture and is behind the cloudiness and sprinkles in
place early Friday.

Not only did temperatures plunge, the frontal passage brought an end to
Chicago's string of three days with 100 percent of the area's possible
sunshine-the longest such spell here since October 29-31.

Big rain tallies in Florida

Since Sunday, 17.21 inches was tallied at Daytona Beach, 13.31 inches
in the Sanford/Orlando area and 24.78 inches in the Ormond Beach area
just north of Daytona Beach.

Chicago-area residents can look forward to a third consecutive day in
the 80s on Thursday. The unseasonable warmth follows Wednesday's
84-degree high at O'Hare International Airport and 85 at Midway-tying
2009's highest readings to date. Temperatures as warm as 88 degrees
occurred at Wheaton and 86 at Flossmoor, but surged into the 90s a
second day in Minneapolis, eclipsing the previous record of 91 dating to
1975.

The warm spell comes to an end with the passage of a wind-shifting cold
front Thursday night. The easterly winds predicted behind the front in
coming days will temper daytime warming, especially near Lake Michigan.

Rains continue in Florida

By late Wednesday, Bunnell, in Flagler County, had tallied 23.75 inches
of rain since Sunday. Rainfall on Wednesday alone totaled 9.27 inches at
Jacksonville Naval Air Station and 6.74 inches at Daytona Beach. The
moisture producing those rains is to sweep into the Midwest encouraging
holiday weekend haze and cloud development.

Temperatures in the Chicago area are to surge to their highest levels of
2009, peaking within striking distance of 90 degrees in the area's
warmest locations. The summer-level temperatures arrive on gusty south
winds within an air mass that sent temperatures to 90 degrees across 14
states.
 Readings topped out at 100 degrees in western Minnesota's Granite
Falls, 110 miles west of Minneapolis, and 97 in the Twin Cities. The
extraordinary warmth was the product of compressional warming as winds
converged along a strong frontal system draped across the area. At one
point Tuesday afternoon, temperatures ranged from 42 degrees at Duluth
to 97 at Minneapolis-a 55-degree difference in only 150 miles!

Downpours in Florida

 Flooding downpours continued in Florida where 12.20 inches was reported
at Palm Coast in Flagler County, between St. Augustine and Daytona Beach
on the state's East Coast. The rain isn't over. An additional 8 to 10
inches is to accompany wind-driven squalls for several more days.

Warm air, responsible for summerlike 90s in the Plains on Tuesday, is
surging toward Chicago. It promises to deliver a three-day string of
80-degree temperatures - the warmest readings here in nearly nine
months.

Rain-organizing jet stream winds have migrated north, to southern
Canada, offering the Chicago region a much needed break from the wet
weather which has produced the area's wettest spring on record at Midway
Airport.

Relief for Florida drought

Sections of Florida in the midst of extreme drought, with some areas
seeing as much as a foot deficit in rain, are being battered by high
winds and heavy rainfall, expected to continue into midweek. Just
southwest of Bunnell, in an area 20 miles northwest of Daytona Beach, a
reported 7.5 inches of rain fell Monday evening, with flooding reported
on secondary roads.

Waves of rainfall Friday pushed spring 2009's precipitation tally into
the top spot at Midway Airport. Daytime rains totaled 0.79 inches at the
South Side site, bringing the season's eye-catching total to 15.44
inches-nearly twice the long-term average of 8.04 inches.
Area farmers continue reeling-unable to get spring planting under way.
Many describe the start to the growing season as the worst they've seen.
Heavy as rains were in sections of the Chicago area, central Illinois
recorded local 5-inch-plus totals in thunderstorms Friday.
Computer models suggest drier weather is on the way. While not
completely rain-free, recent forecasts suggest precipitation amounts may
be only half the 2.88 inches that has fallen at Midway in the past two
weeks.
Frost advisories
Frost and freeze advisories were hoisted Friday night across five Upper
Midwest states. In the Chicago area, falling temperatures by Sunday
morning could trigger light frost conditions in the typically coolest
inland locations.

The second round of downpour-generating thunderstorms in less than three
days threatens flooding and another outbreak of severe weather Friday
afternoon. Soils are saturated and the 1 to 2 inches or more of rain
expected to fall in sometimes-thundery deluges over the coming 24 hours
has nowhere to go but to run off. Flash flood guidance suggests sections
of Chicago's southern suburbs require less than an inch of rainfall to
initiate flooding.

A northbound warm front will be overrun by humid Gulf air producing
thunderstorms in waves Friday afternoon. As the front swings north and
introduces warm humid air into the Chicago area overnight, a squall line
may form and sweep the area. The Storm Prediction Center indicates a
slight risk of severe weather at that time.

Chilly weekend ahead

The chilliest weekend in five weeks follows Friday night's heavy rains
and thunderstorms. Highs Saturday will struggle to reach 60 degrees, and
Sunday will likely hold in the upper 50s.

Thunderstorms towering more than 10 miles above Illinois raced across
the state at 50 m.p.h. Wednesday afternoon and evening, unleashing
downpours and producing powerful winds and lightning across an 800-mile
swath of terrain from Wisconsin to the Oklahoma Panhandle. Lightning
data indicated nearly 2,000 cloud-to-ground strokes were occurring
within a 200-mile radius of Chicago late Wednesday-a total exceeding
16,000 strikes was tallied in just six hours' time. The torrential
downpours late Wednesday evening deposited 1.33 inches in just 15
minutes at Milledgeville in western Illinois, northwest of Dixon, and
caused 6 inches of standing water at Morrison near the Quad Cities.
Late-evening storm gusts downed power lines at Mt. Morris southwest of
Rockford as the squall line marched toward the Chicago area, which had
first been placed under a tornado watch around 6 p.m. Wednesday.

Tornadoes in the Heartland
Nearly two dozen reports of tornadoes had been filed with the Storm
Prediction Center across the nation's Heartland as night fell Wednesday.
One especially deadly twister was produced by a rotating thunderstorm
known as a supercell that forecasters tracked across northern Missouri
into west-central Illinois for nearly four hours.
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune

A warm frontal passage and powerful humid winds that take hold Wednesday set the stage
for what could be a significant severe weather outbreak late in the day into Wednesday
night. Clusters of thunderstorms have flared overnight with the northbound front. An ensuing
flood of Gulf air into the area is to produce the most humid daytime humidities since
September. This will provide fuel for a new wave of thunderstorms expected to assemble into
a squall line in eastern Iowa on Wednesday afternoon then surge eastward, most likely
reaching the Chicago area between 7 and 11 p.m. Computer model energy calculations indicate
an atmosphere capable of fostering supercell thunderstorms, which all too often spawn
dangerous wind gusts and tornadoes.
The National Oceanic and Atmospheric Administration's Storm Prediction Center,
responsible for all of the country's tornado and severe thunderstorm watches, placed sections of
Illinois in a moderate risk three days ago. Issuing such a warning three days in advance
is something the agency has done only seven times in the country since 2001.
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune

Monday's sub-par 61-degree high in Chicago came on the heels of the
area's chilliest morning in 18 days. O'Hare International Airport
registered a 39-degree low while some nearby areas registered frost
level temperatures-among them Waukegan (33 degrees), Kenosha (33) and
Northbrook (34). With the chilly air eastbound, frost and freeze
warnings were hoisted overnight across sections of nine states from
Michigan and northern Indiana east to New England.
Tuesday brings with it the prospect of warmer southerly winds expected
to boost Chicago-area temperatures to close to 70 degrees.

Storm-outbreak possible

The warmth is to be joined by an influx of humid Gulf air Tuesday night
and Wednesday-a development that threatens more ominous weather here,
including what may become the area's most extensive outbreak to date. At
least one computer model is developing a major squall line from Michigan
to Texas by early Wednesday evening and thunderstorms which may impact
the Chicago area.

Chicago's spring has featured a lot of rain but few truly warm days
and very little severe weather. So far the city has logged just one day over
80 degrees -- more than two weeks ago on April 24, when it spiked to a
summery 84 degrees.
While spring rains have been frequent and often heavy, causing
several episodes of flooding, there has been a noticeable lack of severe
weather that typically plagues the region this time of the year. All that
may change this week as surges of warmth on Wednesday and Saturday
may trigger strong thunderstorm development.
Mother's Day featured seasonable temperatures in the Chicago area
with highs reaching the middle and upper 60s. Dry weather was the
rule, though a few showers dampened afternoon festivities. Pea-sized
hail was reported with showers in Oak Lawn and Portage in northwest
Indiana.
Sizzling in the South
Record highs were posted Sunday from Louisiana to Florida. Orlando
reached 97, Ft. Myers 96, Naples 92 and New Orleans 90.
--By Steve Kahn, WGN Weather Center Meteorologist

Mother's Day promises to be a cool one this year with highs struggling to reach the lower
60s. The day will be dry--though a few light showers or sprinkles may develop in the
afternoon--but it should be far better than last year's chilly washout that featured highs
in the 50s and 1 to 2 inches of rain. Though recent Mother's Days have been cool here, the
mercury reached a very warm 88 degrees in 2004 and 85 degrees in 2005. Since the first
proclaimed Mother's Day in 1914, temperatures here have climbed as high as 89 degrees
in 1956 and dropped as low as 29 in 1983. Sunshine returns Monday as temperatures
begin a quick rebound that will boost readings into the lower 80s by Wednesday, courtesy
of increasing southwest winds. The warm-up will be accompanied by a noticeable
increase in moisture, which will lead to the development of clusters of potentially active
thunderstorms that could reach Chicago by Wednesday. Cooler weather will follow in the
storm’s wake Thursday, but another surge of warmth is due to arrive by next weekend.

The deadly squall line that raked far southern Illinois midday Friday,
devastating the Carbondale area on its way across a 1,200-mile swath of
terrain covering sections of nine states, is one for the books. Dr. Joe
Schaefer, director of the National Oceanic and Atmospheric Administration's
Storm Prediction Center, says the "derecho complex is one of
the worst I've seen in the past decade."
Derecho is the term applied to a uniquely long lived and damaging
line of thunderstorms. Their straight line winds and occasional
tornadoes can produce damage over hundreds of miles -- at times, even a
1,000 miles or more. Friday's squall line began as scattered thunderstorms
on the Colorado-Wyoming border, then organized into a line
that was still going strong as it reached eastern Tennessee and the
Carolinas. A second line of storms raced across Illinois late Friday --
this one producing 70 m.p.h. gusts south of the Quad Cities and a brief
tornado touchdown near Little York in western Illinois. The storms
sweep into the Chicago-area overnight, ushering much cooler air into
the region for the Mother's Day weekend.
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune

Thunderstorms erupted for a second day Thursday. Unlike Wednesday's storms, which
deposited heavy downpours over a majority of the Chicago area, Thursday’s storms
targeted the southern half of the region. Lightning production was far less prolific than
the day before--Thursday's storms produced 20 percent of the cloud-to-ground
strokes observed with Wednesday's storms (1,009 cloud-to-ground strokes versus
5,183). But the faster movement of Thursday's storm generated strong wind gusts
clocked at 58 m.p.h. two miles north of Ottawa just after 4 p.m. A succession of
thunderstorm warnings were issued—one of which extended into southern Cook
County. Other storm gusts included 49 m.p.h. at New Lenox and 46 m.p.h. in
Naperville.

Thursday's temperatures reached 80 degrees at Oswego and New Lenox and in Munster,
Ind.; 79 at Chicago's lakefront; and 77 officially at O’Hare International Airport.

Friday will bring the area its sixth consecutive day with a high of 70 degrees or warmer.

Spring temps rank among warmest 24 percent since 1871

Chicago's temperature since March has averaged 44.9-degrees--1.4-degrees above the
long term 138-year average and 1.2-degrees warmer than the same period a year ago.
It places this spring among the city's warmest 24 percent.

Thunderstorms exploded to life Wednesday afternoon as daytime warming destabilized
the atmosphere, encouraging humid air near the surface to ascend and building vast
cumulus clouds that reached 40,000 feet into the atmosphere. Concentrated downpours
from the towering thunderheads drenched Wrigleyville with 1.48 inches of rain and
produced brief flooding in spots. Midway Airport's 0.84 inches of rain through late
evening pushed the city's spring rainfall tally to 13.41 inches-re-establishing the
season to date as the wettest on record here.

Lots of lightning

The first flashes of lightning with Wednesday's fast developing storms occurred
around 1 p.m. on the Mississippi River between Iowa and Wisconsin. Storm development
was so rapid, lightning was arching across Chicago skies only three hours later. A total
of 5,183 cloud-to-ground strokes had been recorded over the six-hour period through
8 p.m. within a 200-miles radius of Chicago. 38% of them especially high amperage
"positive lightning". Typically only 10 percent of lightning bears a positive charge.

Rain-weary Chicago-area residents have just witnessed the longest spell
of precipitation-free weather in nearly a month. But thunderstorm
prospects are to surge later Wednesday afternoon and evening, and again
Thursday afternoon and evening, with an influx of Gulf moisture. A
spotty shower or two isn't out of the realm of possibility into early
Wednesday afternoon. But the primary thunderstorm development is to be
stoked by daytime heating that is to take place beneath a pool of
comparatively cool air aloft. Heating of the lower atmosphere encourages
air to become buoyant and ascend into cooler reaches of the atmosphere.
Computer model vertical-temperature profiles suggest this process could
produce towering cumulonimbus clouds-the suffix "nimbus" always refers
to precipitation falling from clouds-which could extend to heights of
nearly 40,000 feet. Modest winds at the higher steering levels of the
atmosphere could allow any thunderstorms that form to move comparatively
slowly, producing locally heavy rain totals.

70-degree spell to extend to 6 days

The current mild spell that began Sunday is likely to continue through
Friday. If forecasts verify, the six-day string would arrive nearly two
weeks earlier than the average starting date of the season's first
six-day 70-degree spell, (May 15).

The Chicago area is in the midst of its most extended break in rainfall of the past three
weeks. More than half of the days since April's open—19 of the past 35 days (54
percent of them)--have registered rain. The past two weeks alone have seen more than
3 inches of rain (3.16 inches) fall. A shift in the jet stream is behind the drop in rainfall.
Pockets of especially strong winds within jet streams--referred to by meteorologists as
jet streaks--act to lift and cool air, igniting thunderstorm development. But the jet
stream itself has sagged south in recent days, which has diverted the most organized
thunderstorms well south of Chicago.

With rainfall and accompanying cloud cover more scarce than in many recent days,
temperatures have been able to surge. Monday’s 70 degree high followed a similar high
on Sunday and marked the ninth time in 2009 the mercury has reached or exceeded the
70-degree mark. Additional 70s are predicted each day through Friday. And it's not out
of the question this year's second 80-degree day may occur Thursday if widespread
thunderstorms hold off until after sunset.

Thunderstorms will flare Wednesday, however, and could tap a northbound flood of Gulf
moisture to produce downpours at some locations.

High pressure anchored over the Great Lakes will remain strong
across northern Illinois on Monday and then weaken Tuesday as it
heads east and gives way to an approaching low-pressure system
from the west. Soils should continue to dry, and rivers and streams
slowly fall. But clouds and as much as a half-inch to an inch of rain
should spread over the Chicago area Wednesday. After a brief respite
and warm-up Thursday, another weather system should bring
quarter- to half-inch rains Friday.
Storms again hit Southeast
Sunday afternoon, a north-south line of thunderstorms tracked east
through the Gulf Coast states with reports of tornadoes, large hail and
widespread wind damage. There were many reports of trees and
power lines down. A woman was killed by a falling tree in Jones
County, Miss., and a report out of Perry County in west-central Alabama
indicated thousands of trees downed. As the storms continued
east, a severe thunderstorm watch was in effect Sunday evening for
western South Carolina.
--By Paul Dailey, WGN Weather Center Meteorologist

Northeast Illinois is catching a welcome--albeit short-- break in this
spring's prolonged wet pattern. Area rivers and streams are running close to
bankfull or overflowing and soils everywhere are soaked. Indications are the
next storm system will spread showers and thunderstorms back into this area
Tuesday night and Wednesday. That would mean a five-day respite that might
allow rivers and streams to absorb the next round of rainfall without
significant flooding, and some farmers in better-drained areas a chance to
briefly get back into the fields.

Severe storms hit the southeastern U.S.

Saturday afternoon and evening tornado watches were issued covering portions
of states from Texas to Alabama where in addition to many tornado
warnings, there were many reports of golfball-sized hail and damaging winds.
Around 3:30 p.m., the roof of the Dallas Cowboy training facilities
collapsed with several injuries reported.

More rain in the weeks ahead

In the next couple weeks, northern Illinois and southern Wisconsin seem to
be targeted for frequent rain-producing low pressure systems. The National
Weather Service extended 8 to 14-day outlook for May 10-16 forecasts above
normal rainfall over the Midwest and Great Lakes.

The first full weekend of May is to be the nicest here in three weeks. Heavy
rains, including thundery downpours which produced flooding and hail this
past Saturday and Sunday, were among those which rendered the past two
weekends wash-outs. Rainfall at O'Hare totaled 1.41" last weekend and 0.90"
the weekend before. It appears the only threat of rain this weekend comes in
the form of passing sprinkles or even a few brief light showers Sunday
afternoon -- precipitation which may bypass some sections of the Chicago area.
The break in rainfall comes on the heels of an April deemed Friday 6th
wettest in 114 years of records by state climatologist Dr. Jim Angel of the
Midwestern Regional Climate Center. Angel reports statewide precipitation
averaged 6.20" versus the 3.80" considered normal.
Area farmers like Dave Behrens, who farms near Woodstock in McHenry County,
stymied in their attempt to get corn and soybeans in the ground, have grown
frustrated by the recent abnormally wet pattern. Behrens has planted just 5
percent of his corn versus 80 percent a year ago and says, "This is the
worst start in my 23 years of farming."
Weather improvement temporary; waves of rainfall
to keep coming the next two weeks
The weather improvement here is temporary -- likely to last into Tuesday.
That's providing a wet early week storm passes south of the city as
currently anticipated. A southward jog in the jet stream is behind the
improved picture -- though the thunderstorm spawning, high-altitude river of
air is to drift back north into the Midwest by midweek igniting clusters of
thunderstorms -- initially scattered Tuesday night then increasing in coverage
Wednesday. Widespread 1-2" rainfalls are possible.
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune