November 30th/December 1st Winter Storm 2006

30-01 November/December 2006
Winter Storm Chase

General Storm Evolution | Daily Highlights | Snowfall Total Maps | Satellite Imagery

Wednesday | Thursday | Friday |

Historic Winter Storm Event

Eastern United States Composite Radar
WeatherTap Image

Central Illinois Heavy Ice Accumulation
Beau Dodson Photo

Chase Target: Peoria, Illinois
Arrival Date: November 30th at 2:30 a.m.
Driving Time: 5 1/2 Hours
Chase Rating

After review of 00z model data I made the decision that the heaviest snow band would likely be from Southwest Missouri through Central Illinois and into the Chicago area. My first call map was issued on Friday, November 24th. There would also be a band of ice on the southern portion of that line. Computer models indicated that snow totals could exceed 10 inches in some locations. Although models showed the heaviest band a tad to the Nortwest of the Peoria area I felt like the storm might track a bit further to the east and south. RH values at 700 mb indicated that a sharp dry slot would be cutting up through Southern Missouri, Illinois, and Indiana on Friday Morning. I was looking for an area that would have easy access to the interstate. The final cities considered would be St Louis, Columbia, Mo, Springfield, Peoria, Chicago, or Bloomington, Il. The final decision was made at 8 p.m. on the 28th. The target city would be Peoria, Illinois.


Forecast Surface Map Thursday Evening	Forecast Surface Map Thursday Night	Forecast Surface Map Friday Morning	Forecast Surface Map Friday Afternoon

Wednesday, November 29th. Departure Day.

We left for Peoria between 8 and 9 p.m. on Wednesday Night. It would be a 5-6 hour drive ahead of us. It was dark and rain was expected north of Mt Vernon. I wondered if it might not take longer because of worsening conditions further north. Ice was already being reported across the river in Missouri. Temperatures were also starting to fall in the Illinois Counties bordering Missouri. A strong cold front was positioned just to the west and northwest of the KPAH Region. At 8 p.m. the front was entering Western and Central Illinois and then extended into Central Missouri. Another aspect of this storm system was the heavy rain/thunderstorms (see images below) across a large portion of Oklahoma, Missouri, and Illinois. Rainfall totals exceeded 3 inches in some locations. Flash flood warnings were issued for a number of counties because of rapid runoff. Thankfully we only had to drive through 30 minutes of heavy rain and that was near Mattoon, Illinois. Thunderstorms were observed in Mattoon around 1 a.m. There were four flashes of lightning to the northeast of the city. The front hit us around that time. Winds gusted to around 30 mph as the front passed. Temperatures were already beginning to fall while the thunderstorm was occurring. Temperatures fell rapidly behind the arctic cold front. From Mattoon, Illinois to Peoria (approximately 100 miles) the temperature fell approximately 30-35 degrees. Temperatures fell 15 degrees within just a few minutes of frontal passage (see temperature gradient map below).

Wednesday Evening Temperature Map.

7:30 p.m. Weather Radar
WeatherTap

Wednesday Evening Lightning Data.

Wednesday Evening IR3 Satellite

Thursday, November 30th. Arrival Day.

Most of the 30th was dry. Precipitation would remain to our southwest and south until late afternoon. There was a rapid expansion of radar returns after 4 p.m. Sleet and freezing rain began to fall in Peoria soon after the sun went down. For most of the evening the precipitation would fall in the form of sleet with some occasion flakes of snow mixed in. There was also a brief period of heavy rain. Thundersleet was observed on several occasions between 11 p.m. and 1 a.m. KILX rdar showed several bands of high dbz levels move over the City of Peoria and surrounding areas. The 500 mb low at 00z on Thursday Evening was still located over Eastern Oklahoma. National Composite radar showed a rapidly expanding area of precipitation over most of the Missouri Valley. The low would eventually strengthen and track from Southern Missouri into East Central Illinois and West Central Indiana (see maps below). Strong wind fields were noted across much of the TN and Ohio Valley Region. This would help aid severe thunderstorm development overnight on Thursday and into Friday Morning. A number of severe weather events were reported.


6 p.m. Temperature Map for Missouri and Illinois	6 p.m. Surface Pressure Map	6 p.m. 3 Hour Pressure Tendency Map	6:15 Central Illinois Radar


Peoria Radar Animation Thursday 6:15 p.m.	Peoria Radar - 8:20 p.m. Thursday Evening.	Peoria Radar - 9 p.m. Radar Thursday Evening	9:15 p.m. Bright Banding


9:15 p.m. Bright Banding	RUC Evening Surface Forecast Map	10:15 Central Illinois Radar	G.R. Storm Reports Map for Missouri and Illinois

Friday, December 1st (the main event)

The significant part of this winter storm began in earnest during the early morning hours of December 1st. Peoria had moderate to heavy sleet during most of the early evening hours. Eventually enough cold air filtered in aloft to change all the precipitation in Peoria to snow. This was after 1-2 inches of sleet had already fallen. Once the precipitation changed to snow it remained as snow through the mid-morning hours. Snow ended around 11 a.m. After all was said in done we had over 10 inches of snow in Downtown Peoria. Area measurements revealed a range from 6-14 inches. Amazingly there was a significant drop-off of snowfall amounts as you traveled just a few miles south and east of the downtown area.

During the early morning hours thundersnow was reported across portions of Central Illinois (also portions of Oklahoma and Missouri). Strong Vertical Lift was noted on the model forecasts prior to this event. Thundersnow was placed in my forecast as early as Monday/Tuesday.

At 0600z Friday, December 1st a strong 500mb shortwave was located over Southwest Missouri. This shortwave was strengthening and moving east/northeast towards Central and Southern Illinois (see charts below). Heavy snow and thundersnow developed on the north side of this 500mb low. Snow rapidly expanded and spread into Illinois during the overnight hours of the 30th. By Friday Morning, December 1st, much of Central and Northern Illinois was covered in moderate to heavy snow. Snowfall rates of 1-2 inches an hour were reported in some locations. I observed heavy, wind driven, and fine size snowflakes from 5 a.m. through 10 a.m. (see 24 hour national radar animation) also (KILX Radar Animation from 0000 through 1800). The snowflakes were almost like sand blowing on a beach. It was difficult to keep the snow out of the camera equipment and clothing. The winds were gusting in excess of 35 miles per hour. Sustained winds appeared to be between 20-25 for several hours. I took shelter in a seven story tall parking garage to protect my camera gear. I was able to get a few photographs from that location. Wind chill values were below zero at times. This made for difficult photography (to say the least). The wind seemed to funnel through the garage at times and would cause a roaring noise that resembled a weak tropical storm.

At 5 a.m. the streets of Peoria were snow and ice packed. They were virtually clear of traffic with the exception of just a few motorists who "thought" it would be a good idea to venture out onto the streets. I witnessed a number of cars that were stuck in the snow with drivers waiting for tow trucks. I also observed a number of abandoned vehicles in the streets of the downtown area. Local officials were urging people not to travel.

Visibility was less than one block at times during the height of the snow event (see METAR Data and Here). Snowdrifts exceeded four feet in some locations in the downtown area. Cars had drifts up to their windshields on several streets. Although I was unable to experience the ice I did drive through some of the hard hit areas of Central Illinois on my way home on Saturday Morning. Photographs that were taken show heavy ice accumulation on trees and power lines. I would estimate the thickness of the ice to have exceeded 1 inch. Severe tree damage was noted in several Central Illinois Counties. Large areas were also without power for over one week following the ice storm. At one point more than 2 million people were without power across the Central United States because of this powerful winter storm system. Two blogs were kept on the event. Both of these blogs can be found on EasternUSwx.

| Blog 1 | Blog 2 |

Storm Prediction Center Mesoscale Discussions

Missouri and Illinois Mesoscale Discussions

November 30th/December 1st - All Mesoscale Discussions


12 a.m. 500mb Map December 1	7 a.m. 500mb Map December 1	Noon 500mb Map December 1	6 p.m. 500mb Map December 1


1 a.m. 850 - 500mb -ub/s mrhum and Thickness	1 a.m. 850mb Temperature 1000-850mb Thickness	3 a.m. National Radar	4:30 a.m. Thundersleet and snow across Central IL.