Monday, May 2, 2016

Science Behind the Recent Hail Storms

Understanding the science behind the recent severe thunderstorms in Edgar County is easier when you know the science behind a general thunderstorm.
Thunderstorms require three ingredients to form – moisture, lifting, and instability. Highs on April 26 topped out near 80 degrees as southerly winds brought in warm moist air from the Gulf of Mexico. These conditions fulfilled the first ingredient; the second and third arrived along an advancing cold front. A cold front is the leading edge of an air mass that is cooler than the air already at the surface. Since cold air is denser than warm air, the front lifts the warm air up into the atmosphere and it is replaced by the cooler air. This interaction between the air masses destabilizes the atmosphere and with that instability, forms a thunderstorm. Similar conditions were in place Sunday as the sunshine heated the atmosphere and it became unstable.
Once the ingredients are in place, the lifting produces cumulous clouds as the rising air condenses and establishes an updraft. The updraft supports the thunderstorm by ushering warm, moist air into the storm. Eventually, the moisture condenses into rain drops and they fall when they are too heavy for the updraft to keep them in the cloud. 
The storm that would drop hail on Paris developed around 3 p.m. April 26 across northern Clark County. With ample instability and moisture, the cell thrived, and continued to develop over Paris. The winds in the storm’s updraft began to lift raindrops high into the atmosphere where they froze and collided with other droplets. As these droplets started falling back to the surface, the updraft caught them and once again lifted them into the sub-freezing portions of the atmosphere where they grew into hailstones. This cycle continues, forming larger and larger hail, until the updraft can’t support the hailstones and they fall to the surface.
Around the same time, the storm stalled along the cold front, barely moving to the east. The nearly stationary storm drenched the city in heavy rains and dropped up to golf ball size hail across eastern portions of the city and points east along the Clinton Rd. and U.S. Highway 150.
As one section of the storm weakened, another rapidly developed and took its place, resulting in periods where the hail would briefly stop before another round began. This phenomenon is known as “training” where storms will continually form over the same area and barely moveSunday’s storm; however, was a little different.
Developing over Moultrie County in central Illinois, this cell grew in strength and intensity by feeding on moisture and daytime heating as it pushed east-northeast over Coles County. Once it crossed Interstate 57, its updrafts rapidly intensified, blowing rain and hailstones high into the atmosphere. The updraft was strong enough to support two inch size hail as it passed over Oakland, but continued to intensify and produce three inch size hail south of Brocton.
As the storm moved into western Edgar County, it began to rotate. Rotation in a thunderstorm is caused by wind shear and a strong updraft. Wind shear is found in the upper atmosphere where horizontal winds shift suddenly in direction and speed. If a thunderstorm grows tall enough, its updraft – the winds supporting the thunderstorm – can force the horizontal winds to spin vertically, causing the storm to rotate. If these spinning winds in the cloud connect with winds at the surface, a tornado will form. This storm didn’t produce a tornado, but a funnel cloud was spotted near Redmon. 
Sunday’s storm was considered a “supercell” because of its strong, rotating updraft that generated very large hail and funnel clouds.

Tuesday, April 26, 2016

Severe Weather Outbreak Forecasted for Tuesday

The Storm Prediction Center has highlighted a Moderate Risk for severe weather for areas from Nebraska to southern Oklahoma on Tuesday. In that area, a tornado outbreak is possible with a few strong tornadoes and large hail. Eastern Kansas is bearing the brunt of the system, and cities like Witchita are preparing now for potential storms/tornadoes as well as cities like Tulsa and Oklahoma City further to the south. But before those storms developed, a line of storms pushed its way across Missouri. This line became severe just northwest of Kansas City, MO, capable of producing 60 mph winds and large hail. It was severe warned across its entire path through KC and Jefferson City, and is now knocking on St. Louis's western edges. A Severe Thunderstorm Watch has been issued for portions of western and south central Illinois including Springfield, Taylorville, and Effingham as the storms push toward those areas. Numerous cells have also developed across east central Illinois, but those are expected to become severe. If they do reach severe limits, they shouldn't have enough energy to maintain that strength for long. While storms are popping in Illinois, the most severe storms look to impact portions of the Great Plains this evening and then move into areas overnight that have already dealt with severe storms. Spring storms have finally arrived!

Monday, April 18, 2016

20th Anniversary of Illinois' Largest Tornado Outbreak

The 20th anniversary of Illinois' largest tornado outbreak on record will be marked Tuesday, April 19 (the outbreak occurred in 1996). After surveys were conducted, a total of 39 tornadoes touched down across the state causing 74 injuries, one fatality, and a damage estimate in excess of $100 million. Ten of those tornadoes spawned from one supercell thunderstorm that produced an F2 tornado in Jacksonville and F3 strength tornadoes in Decatur, Champaign/Urbana, and Ogden. Before that supercell entered central Illinois, another supercell thunderstorm dropped two tornadoes in Coles County and two more in Edgar County. Both of Edgar County's tornadoes touched down just northwest of Paris. One touched down at 5:10 p.m., three miles northwest of Paris, destroying a barn. It continued east-northeast and damaged six farms in the area, including the destruction of several machine sheds, a couple barns, and grain bins. One residence had moderate roof damage and another had broken windows caused by baseball-sized hail. The tornado lifted at 5:16 p.m. after crossing Highway 1 three miles north of Paris. It was later rated as an F1 tornado with a max width of 440 yards. The other tornado touched down at 5:12 p.m. 1.5 miles north-northwest of Paris, near Cherry Point Rd. and County Rd. 200W, destroying a machine shed. It lifted briefly and touched down again at the intersection of Steidle Rd. and Tucker Beach Rd., damaging a 3-car garage. It continued east-northeast and damaged another machine shed, numerous trees, and a baseball field. At Twin Lakes Park, several benches, trees and a small shed were damaged. It traveled across the lake and flipped a boat lift, before dissipating at 5:16 p.m. This tornado was rated an F0 tornado with a max width of 220 yards. Had this tornado occurred present day, it would have traveled across the parking lot on the Paris High School campus just south of the railroad crossing. Several windows were blown out of homes in Brocton as well as Paris where golf ball-sized hail fell. Information about the tornadoes is courtesy of the National Weather Service office in Lincoln.

Monday, April 11, 2016

Spring Looks to Finally Arrive

After a week of cold, windy, rainy, and even snowy conditions, spring finally looks to make an appearance. Numerous Freeze Warnings have been issued for Edgar County over the past 2 weeks (4 to be exact). Overnight lows have dropped into the upper 20s which has threatened new plant growth. Another warning is in effect for Tuesday night, but hopefully it will be the last since the average last day for a spring freeze (28 degrees) is April 5. Friday evening, there was enough cold air above the surface to allow sleet, snow, and graupel to form.Cloud cover and northwesterly winds have not help the situation any since they have held down temperatures during the day. However, after a rainy and cloudy Monday, the weather looks to improve and go from below average temperatures to above average temperatures. Tuesday looks to be sunny and cool with highs in the 50s, but from there, temperatures are on a steady increase with abundant sunshine. By the weekend, temperatures will be near or above 70 degrees! Long-term forecasts show the jet stream staying to the north which will keep a flow of warm air streaming into the Midwest from the Gulf of Mexico.

Monday, April 4, 2016

Wicked Winds Rip Through Central Illinois

A low pressure system moved across southern Wisconsin Saturday afternoon, creating a tight pressure gradient between it and the high pressure in the Great Plains. If the pressure gradient tightens, the winds will will become stronger as air rushes toward the low pressure system from the high. The National Weather Service issued a Wind Advisory for Edgar County Friday night for wind gusts near 50 mph, but there were times Saturday where sustained winds and wind gusts reached High Wind Warning criteria. The Indianapolis office did upgraded their counties, including Vermillion and Vigo, to the warning late Saturday afternoon. Some of the top wind gusts in central Illinois were 66 mph south of Newman, 62 mph in Springfield, 61 mph in Mattoon, and 59 mph Arcola. These winds, if produced in a thunderstorm, would be warned under a Severe Thunderstorm Warning. Paris's top wind gust was 56 mph at the Edgar County Airport. EnerStar battled power outages in their rural areas most of the afternoon as the winds knocked down trees. Numerous semis, trucks, and trailers were blown off roadways, including one north of Paris on Route 1. 10 miles southeast of Paris, numerous trees were snapped or uprooted, siding was partially blown off a house, and part of a roof was blown off an outbuilding. A dust storm was reported in Shelby County, IL between Shelbyville and Windsor. In Terre Haute, a metal communications tower fell on the old jail and a nearby law office just across the Wabash River. After calming down Saturday night (when temperatures dropped into the upper 20s), the winds picked back up from the south Sunday, but they weren't as bad as Saturday's winds.

Monday, March 21, 2016

Severe Weather Strikes Central Illinois Tuesday

Last Tuesday (March 15), severe storms rapidly developed across northeastern Missouri and tracked into western Illinois prompting Tornado Watches and Warnings as well as Severe Thunderstorm Watches and Warnings. Crossing the Mississippi River near Keokuk, Iowa, Tornado Warnings were issued as reports of ping pong ball sized hail started to come in. Tornadoes would eventually be confirmed just to the north and northeast of Macomb, Illinois, the home of Western Illinois University. Other cell developed around 6:30 p.m., north of St. Louis and began tracking straight toward Illinois' capital: Springfield. Numerous local and national reporters were there as election results were starting to stream in; however, just before 7:45, the National Weather Service issued a Tornado Warning for northern Sangamon County that included Springfield. Sirens wailed as reporters scrambled for cover. A funnel cloud was reported over downtown Springfield as lightning illuminated the sky. A tornado was confirmed Wednesday on the western edge of the city. Another tornado was confirmed within the city limits of Peoria, Illinois. A Weather Channel meteorologist was live along the river as sirens sounded across the area. These supercell thunderstorms continued to race northeast toward Chicago and joined together producing damaging winds and large hail. Locally, large hail fell in northern Clark and southern Edgar counties Tuesday night, prompting a Severe Thunderstorm Warning. TV station employees across Central Illinois had a busy night as storm warnings and election results battled for the bottom of the screens.

Monday, March 14, 2016

Spring Storms Make an Appearance

An Enhanced Risk for severe weather was outlined by the Storm Prediction Center Sunday, March 13, 2016. All types of severe weather would possible across Arkansas, eastern Oklahoma, western Tennessee, and northern parts of Louisiana and Mississippi including damaging winds, large hail, and tornadoes. Three Tornado Watches were issued through out the day stretching from eastern Oklahoma to points to the east of Memphis, Tennessee. Confirmed tornadoes and radar-indicated rotation prompted Tornado Warnings across a large part of Arkansas and even one for downtown Memphis! Ping Pong ball size hail was also falling from the skies at one point. There were confirmed tornadoes and the National Weather Service will conduct surveys today to determine ratings. Tuesday, the day voters in Illinois will be headed for the poles, the Storm Prediction Center has placed roughly the northern 2/3 of the state under a Slight Risk for severe weather. Damaging winds look to be the primary threat, but large hail and tornadoes will also be possible. Newsrooms will be busy enough with election results, but add in a couple of severe storms and all of the local television stations in Illinois will be scrambling to keep viewers updated with the latest information. Will Donald Trump and Hillary Clinton's election results dominate the bottom of the screen or will radars and crawls, warning of severe weather, hit the air waves? Now that March is almost halfway through, it looks like Mother Nature is starting to through tornadoes and severe weather into the picture across the country.

Tuesday, March 8, 2016

Spring Arrives with Warm Temperatures and Rain

Now that spring has arrived, meteorological spring, anyway, temperatures seem to be warming up. Yesterday (Monday), temperatures climbed into the 60s across the area and near 70 today. Temperatures are expected to remain in the 60s for the remainder of the week and they might climb into the lower 70s next week. NOAA released a report today that showed every state besides two (Nevada and Utah), saw above average temperatures during winter. Meteorological winter is December 1 to March 1. However, all of these warm temperatures are being accompanied by rain. The next 6 have at least a 30% chance of rain. Over 2 inches of rain is expected the next 3 days with higher totals in areas where thunderstorms develop. Another system will develop this weekend, bringing the potential for another 1 to 2 inches of rain with it. Flooding will be possible (and likely if multiple storms occur over one area) across central Illinois as the ground is already saturated and there is not as much vegetation now as in the summer to absorb the moisture. Maybe it will be March showers bring April flowers this year.

Monday, February 29, 2016

Blizzard Strikes Edgar County

Early Wednesday morning (February 24), the National Weather Service office in Lincoln issued a Blizzard Warning for Edgar and surrounding counties to the north and west. This was the first Blizzard Warning for the county since 2012. Two area school districts, Charleston and Mattoon, had already called off school for the 24th the previous evening. By 6:00 a.m., all Edgar County schools had closed along with South Vermillion, Champaign, Danville, and Effingham. Around 6:30, Marshall also made the call to close schools for the day. Eastern Illinois University and Lake Land Community College also cancelled classes Wednesday. Rain changed to snow in Paris mid-morning, and was it started falling, it was heavy! The ground quickly became covered in snow as it continued to fall. Just after noon, thunder rumbled across Paris - otherwise known as thunder snow. The snowfall wasn't the main problem, however. Wind gusts were approaching 50 mph during the day with sustained winds of 20 to 35 mph! These winds were the cause of the warning, not the accumulations. The NWS will issue a Blizzard Warning when winds are sustained around 35 mph during falling or blowing snow which will reduce the visibility below a quarter of a mile for 3 hours or more. This criteria wasn't quite met for the duration required, but there were strong winds and low visibility across the county. Numerous power outages occurred Wednesday with EnerStar Electric Cooperative reporting 59% of all of their customers without power at one point. Some of the outages were caused by power lines that fell across Illinois Route 1 which forced the closure of the highway Wednesday afternoon until crews could clean up the area. By 7:00 a.m. Thursday morning, 6 inches of snow had fallen in Paris and schools in Kansas, Chrisman, Mattoon, Arcola, Georgetown-Ridge Farm, and Paris were once again closed.

Tuesday, February 23, 2016

The Challenges of Winter Weather Forecasting

Another system is approaching the area and will strike tomorrow (Wednesday) morning. Rain will initially push into the air before a push of colder air changes the rain to snow. When will the rain change to snow? That remains to be the biggest question about this forecast and almost every model run shows something different. The National Weather Service issued a Winter Storm Watch for Edgar County early Tuesday morning calling for rain to change to snow late morning, producing "4 to 6 inches" of accumulation. The heaviest snow band looked to set up north of IL-16 and east of I-57; however, some models are pushing the heavier snows west, between I-57 and I-55. For example, at noon, one model run had Paris receiving 8.4 inches of snow while another had 1.4! Wherever the heaviest band sets up, there will be a sharp gradient in snow totals with 20 miles making a big difference in totals. Another forecast headline will be strong northerly winds of 20 to 30 miles per hour gusting near 40 mph. This winds will greatly reduce visibilities which will cause travel concerns even if snowfall totals are low. All of these factors continue to develop and change which probably results in headaches for area meteorologists. So, if you know one, it might not hurt to pick up some Tylenol at the store (unless it is sold out along with the bread and milk).

Thursday, February 18, 2016

A Snowy Valentine's Day

Valentine's Day in Edgar County was cold, breezy, and snowy. The first round of snow showers moved through during the pre-dawn hours producing less than an inch of accumulation in most areas. A break in the action occurred during the morning, before another wave moved through. This wave of snow was heavier than the first and larger in area. Visibilities were reduced to a quarter of a mile as the heavy snow bursts pushed through. The heaviest snow fell in the southern portions of the county where I measured 3.9 inches of total accumulation ten miles southeast of Paris. In Paris, the waterworks measured 3 inches of snow while The Prairie Press' StormTracker south of Brocton measured 2.5 inches. The snow quickly covered roads as road crews tried to clear them. Major pileups occurred on area interstates as the snow fell, too. One, with eight cars involved, happened on Interstate 57 near Neoga, IL. Another pileup, with a reported 50 cars involved, took place on Interstate 70 at mile marker 33 in Putnam County, IN. There was also an accident on I-70 near Martinsville along with other slide-offs around Clark County. Looking back at past events, even four inches of snow does not seem like much, but this event left the most snow behind in the 2015-2016 Winter.

Tuesday, February 9, 2016

The Difference in Advisory Criteria within Illinois and Indiana

In 2015, when temperatures and wind chills plummeted below zero, the National Weather Service offices in the region issued Wind Chill Advisories and Warnings. However, the criteria between three offices the cover Illinois are different. The NWS office in Chicago will issue a Wind Chill Advisory when wind chills drop below -20. This office covers most counties in northern Illinois along with five counties in northwestern Indiana. Just to the south, including places like Peoria, Bloomington, Champaign and Danville are covered by the NWS office in Lincoln. They issue Wind Chill Advisories when wind chills drop below -15. While Lincoln covers Flora, Olney, and Lawrenceville, the NWS office in Paducah covers the cities just to the south including Fairfield and Albion and well as Carbondale. They issue advisories when wind chills drop below -10. So, if you live in a city that borders the office boundaries, you might be under an advisory when the cities to the north where it is colder doesn't have an advisory. This leads some confusion when broadcasting the alerts.
As an FYI, the NWS office in Miami will issue advisories when wind chills drop below freezing! (32)

Tuesday, February 2, 2016

5 Year Anniversary of Ice Storm 2011

Blizzard conditions developed across central Illinois on Groundhog Day in 2011. However, here in east central Illinois, an ice storm developed. Schools were closed Tuesday through Friday all of the roadways were covered in a sheet of ice. Electric crews were stretched thin as they battled the ice on the power lines. In the southeast portion of Edgar County, lines were down due to the the winds snapping the wires together. The electricity was out for 4 days. By Friday afternoon, temperatures warmed enough to start melting the ice of the roads, power lines, and trees (which was another cause of power outages). Over in Springfield, 18 inches of snow fell! Combined with the gusty winds, 5 foot drifts were recorded by the weather service office in Lincoln. Luckily for us, today's Groundhog Day Blizzard struck Iowa and not Illinois, although severe weather is possible across the southeastern portion of the state.

Tuesday, January 26, 2016

'Blizzard of 2016' Slams the East Coast

Meteorologists knew that an upcoming storm system taking aim on the mid-Atlantic and northeastern United States had the potential to be big -- and it was. Initial projections had the heaviest snow falling to the northwest of Washington D.C. across northern Virginia and eastern Maryland. That area saw around 30 inches of snow with 40 inches falling in one West Virginia location. Further to the south, freezing rain created ice across southern North Carolina and South Carolina downing power lines and causing hazardous travel. The heavy snow hit the I-95 corridor (D.C., Baltimore, Philedelphia, and New York) late Friday and ended Saturday night. The strongest winds occurred Saturday with gusts up to 50 mph causing blizzard conditions. Due to the timing, traffic was not as heavy and most residents stayed in their homes as advised. 23 inches of snow fell in Washington D.C., but heavier snow fell in New York City where 28.6 inches were recorded in Central Park - a tenth of an inch shy of tying the record for the most snowfall! New York City banned travel within the city so emergency crews and snow plows could continue the work through the storm. Monday morning, conditions were still bad enough in D.C. that the federal government and public schools were closed along with the schools in Baltimore and Philedelphia. The U.S. House of Representatives cancelled all of their sessions this week, too. Public schools remained closed in the same cities Tuesday as residents continue to dig their way out of the Blizzard of 2016.

Tuesday, January 19, 2016

Arctic Air Prompts Wind Chill Advisories

Brutally cold conditions moved into the northern half of Illinois over the past weekend. In Paris, temperatures fell to -2 at the waterworks and to 1 above at the Edgar County Airport. At the airport, the wind chills dipped down to -17! Wind chill is measured in terms of how cold it feels on exposed skin. With the wind chill values below -15, the National Weather Service office in Lincoln issued a Wind Chill Advisory for Edgar and surrounding counties (as well as NWS Indianapolis). When the values are that low, frostbite can set in on exposed skin in as little as 30 minutes. If the wind chills get below -25, the National Weather Service will issue a Wind Chill Warning which we have seen the past couple of years. Now, temperatures are warming up a bit (upper teens), but will continue to rise as the next storm system moves in. Snow will be accompanying this system as it pushes through the area, producing snow accumulation of one to three inches. More snow is expected south of this area, where a Winter Weather Advisory and a Winter Storm Warning will be in effect tonight and tomorrow morning. After this system rolls through, minor snow accumulations will be possible Thursday and next Monday, but both events are still a few days out and will need to be watched to see if the forecast shifts.

Monday, January 11, 2016

Old Man Winter Strikes Edgar County

The first cold blast of 2016 (and the winter of 2015-16) struck Edgar County over the second weekend of January. December, a month typically averaging highs in the mid 30s, saw daytime highs in the 40s along with a few highs in the 50s! El NiƱo, the warming of the waters in the Pacific Ocean, is  likely to blame. However, winter was bound to strike again -- and it did. Rain was falling most of Saturday (Jan. 9), but as a cold front approached and moved through, temperatures began to tumble. Almost an inch of rain was common until the rain changed to snow later that evening. Only trace amounts of snow accumulation was recorded across the county with higher totals across Indiana. Temperatures continued to tumble into Sunday morning, producing a low of 11° at the Edgar County Airport. Northwest winds gusting near 30 mph produced subzero wind chills Sunday morning as well. After an Alberta clipper system pushes through tonight, winds will once again usher in cold air. Waking up Wednesday morning, expect temperatures near 5 degrees with subzero wind chills.

Thursday, January 7, 2016

2 Year Anniversary of 2014's First Winter Storm

Starting Sunday, January 5, 2014, a winter storm slammed the region dumping a foot of snow in most places. After the precipitation came to an end, gusty northerly winds picked up producing huge snow drifts across the Edgar County, most notably in the northern portions. As conditions worsened Sunday evening, the Edgar County Highway Department and the Edgar County Emergency Services and Disaster Agency (ESDA) closed all of the roads in the county. The roads would remain closed to non-emergency personnel through Tuesday morning. Snow plows fought a never ending battle with the drifting all week as township roads continued to drift shut. The winds also plummeted wind chills 30 to 40 degrees below zero Monday and even Tuesday morning. Temperatures during this time were ranged from 5 to 15 degrees below zero. Due to the frigid temperatures, snow drifts, and road conditions, Paris schools were closed for the week, adding an additional week to Christmas break. As an interesting turn of events, county schools were also closed January 7 and 8 of 2015. These closings were caused by none other than sub zero temperatures and wind chills 10 to 20 degrees below zero. January 7, 2016, brought above average temperatures to the region in the upper 40s along with a chance of rain. Tomorrow (January 8), temperatures near 50 are expected in Paris. What a difference a year (or two) can make!