Winter Storm in Illinois, December 26, 2009

Name: Winter Storm in Illinois, December 26, 2009
Start: 2009-12-26T02:00
End: 2009-12-26T22:00
Location: Illinois

December 26, 2009 · NWS LOT · 9 events in 9 counties and zones

A slow moving winter storm moved across northern Illinois on December 26th. Snow began to fall during the early morning hours and continued through the late evening hours.

Where it happened

Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 9

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS LOT wrote it up.

A slow moving winter storm moved across northern Illinois on December 26th. Snow began to fall during the early morning hours and continued through the late evening hours. The snow was heavy at times in some areas and the snow to water ratio was quite large with the driest snow reported to be 40 to 1. A foot of snow fell across the northwest suburbs of Chicago with a large area receiving six inches or more. Snowfall totals included 12.1 inches in St. Charles; 12.0 inches in Elburn; 12.0 inches in North Aurora; 12.0 inches 1 mile north of Carol Stream; 11.9 inches 7 miles north northwest of St. Charles; 11.1 inches in Batavia; 10.6 inches in Streamwood; 10.3 inches in Elgin; 10.0 inches in Woodstock; 9.4 inches 4 miles north northwest of Rockford; 9.2 inches 3 miles southwest of Barrington; 8.9 inches in Mundelein; 7.5 inches in Island Lake; 6.7 inches in Downers Grove; 6.2 inches in Roscoe; 6.1 inches in Rockford and 6.0 inches at Chicago O'Hare Airport.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Chicago, IL wrote its last area forecast discussion before the first event at Dec 25, 11:03 PM CST, 2 hours 57 minutes earlier.

Area forecast discussion, Dec 25, 11:03 PM CST, 2 hours 57 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1103 PM CST FRI DEC 25 2009

.DISCUSSION...
300 PM CST

SHORT WAVE TROF NOW ROTATING NORTHWARD FROM CENTRAL IL AND
SOUTHERN IND EARLY THIS AFTERNOON. AREA OF PRECIP BECAME MORE
DEVELOPED ACROSS CENTRAL IL DURING THE MORNING AS THE TROF TURNED
NORTHEASTWARD ACROSS THE MID MS RIVER TO SOUTHERN IL IN RESPONSE
TO THE APPROACHING TROF.

PRECIP HAS SPREAD ACROSS NW IND AND NORTHERN IL INTO SOUTHERN WI
DURING THE LATE MORNING AND EARLY AFTERNOON. RA QUICKLY CHANGING
OVER TO SN AND WILL DO SO ACROSS FAR NE IL AND NW IND IN NEXT HR
OR TWO AS COLD LOW LEVEL AIR THAT HAS NOW WRAPPED ALL THE WAY
AROUND TO THE SW AND S SIDE OF THE SYSTEM RAPIDLY ADVECTS NNE ON
25-35KT LOW LEVEL FLOW.

WILL BE SOME MINOR ACCUMULATING SN MID AFTERNOON INTO EARLY
EVENING TIL UPPER TROF CROSSES OVER FAR NORTHERN IL. THIS LIGHT SNOW
ACCUMULATION...ALONG WITH THE RAPID DROP INTO THE 20S AS THE
OCCLUDED FRONT PUSHES THRU THE REMAINDER OF THE FA WILL LIKELY
RESULT IN SLICK SPOTS AS RAINFALL OF LAST NIGHT AND THIS MORNING
LIKELY WASHED ALL SALT AND OTHER MELTING AGENTS FROM PAVEMENT SO
ANY WET SPOTS TO QUICKLY FREEZE...ESPECIALLY USUAL CULPRITS:
BRIDGES...ELEVATED RAMPS...ETC AS THEY EXPERIENCE FREEZING TEMPS
FROM BOTH ABOVE AND BELOW.

THIS PD OF SNOW TO TAPER OFF/END DURING THE FIRST PART OF THE
EVENING BUT THEN THE NEARLY CONSOLIDATED UPPER LOW...CURRENTLY
OVER THE MO-IA BORDER...DRIFTS ENE THEN NE TO SE WI BY 12Z SAT.
EXPECT AT FIRST JUST FLURRIES AND SCATTERED A -SHSN NEAR/UNDER THE
UPPER LOW.

OVERNIGHT AND SAT H7 AND H8 LOWS PROGGED TO TRACK NEWRD FROM SE IA
TO OVR/NEAR S CENTRAL WI. MODELS SHOW AREA OF FAIRLY STRONG UVV
FROM ISENTROPIC UPGLIDE AS WAA TO BE OCCURRING IN THE LOWER-MID
LEVELS. MODELS GIVING 0.15 TO 0.2 QPF DURING THE DAY SAT AS A
RESULT SO FORECASTING A SNOWFALL OF 1-3 INCHES ACROSS MUCH OF FA.

UPPER LOW TO DO AN COUNTER-CLOCKWISE LOOP OVER SRN WI AND NORTHERN IL
DURING SAT AND SUN. THIS KEEPS CHANCES OF LIGHT SNOW AND SNOW
SHOWERS AND ACCOMPANYING MINOR ACCUMULATIONS GOING FOR THE AREA
TIL LATE SUN NIGHT WHEN UPPER LOW FINALLY MOVES FAR ENOUGH OFF TO
THE E OVR THE CENTRAL GRTLKS.

RIDGING BUILDS IN FROM THE PLAINS LATE MON INTO TUE AS ANOTHER UPPER
TROF MOVES FM THE ROCKIES OUT OVR THE HI PLAINS. AS THIS TROF
CROSSES THE CENTRAL MO VALLEY AND APPROACHES THE MID MS VALLEY
OVERNIGHT TUE CHC OF -SN WILL ALSO SPREAD E ACROSS THE REGION FOR
WED.

REGARDING HYDROLOGIC ISSUES...WATER LEVELS ON STREAMS AND RIVERS
WILL CONTINUE TO RISE TODAY AND TONIGHT THOUGH LATEST FORECASTS
ARE FOR CRESTS TO BE BELOW FLOOD STAGE...EXCEPT MINOR FLOODING
FOR VERMILION AND ILLINOIS RIVERS.

TRS

&&

.AVIATION...
1045 PM CST

0600 UTC TAFS...MAIN FORECAST FOR THE OVERNIGHT HOURS WILL FOCUS
ON SNOWFALL COVERAGE AND IMPACT ON VISIBILITY. LATEST RADAR
IMAGERY SHOWS THAT THE SNOW HAS BECOME RATHER SPOTTY...BUT FEEL
THAT RADAR MAY BE UNDER REPRESENTING SNOWFALL AS MOST OF THE
METARS INDICATE SOME FORM OF SNOW IN THE PRESENT WEATHER
INDICATOR. THUS FEEL THAT THE RADAR RETURNS REPRESENT THE HEAVIER
SNOW AND LIGHT SNOW MAY BE ESCAPING DETECTION. SO...TIMING OF
INDIVIDUAL BURSTS OF SNOW REDUCING VISIBILITY WILL BE QUITE A
CHALLENGE OVERNIGHT. GIVEN THE SPOTTY NATURE OF THE HEAVIER
SNOW...HAVE GONE WITH PREVAILING 6SM -SN TO START OUT THE 06Z
UPDATE...WITH A TEMPO 2SM. CONFIDENCE IS LOW AT THIS TIME FOR
TIMING AND DURATION OF IFR VIS RESTRICTIONS...BUT FEEL THAT THERE
WILL BE PERIODS OF IFR VIS DURG THE REMAINDER OF THE NIGHT.
CEILINGS SHOULD BE LESS PROBLEMATIC. WHILE CIGS HAVE GENERALLY
IMPROVED TO VFR ACROSS NRN IL...SHORT TERM GUIDANCE AND UPSTREAM
OBS SHOW SOME TENDENCY FOR MVFR CIGS...SO HAVE GONE WITH MVFR CIGS
IN THE TEMPO AND THEN RETURNED TO PREVAILING MVFR DURG THE MORNING
HOURS.

GUIDANCE STILL INDICATES A MODEST MID LEVEL IMPULSE ROTATING
AROUND THE MAIN UPPER LOW...SO WILL KEEP A PERIOD OF 2SM VIS
REDUCTION FROM LATE MORNING TO LATE EVENING. EVENTUALLY...THE
UPPER LOW WILL BEGIN TO EJECT NEWD TOMORROW AFTERNOON OR
EVENING...AND WINDS WILL EVENTUALLY SHIFT FROM PREVAILING SLY TO
MORE WLY. DECREASING MOISTURE SHOULD ALLOW FOR PCPN INTENSITY TO
TAPER OFF...BUT CYCLONIC CURVATURE SHOULD BE SUFFICIENT TO ALLOW
SOME LIGHT SNOW TO CONTINUE INTO THE NIGHT.

KREIN

&&

.MARINE...
123 PM CST

WINDS ARE GRADUALLY SUBSIDING OVER THE LAKE TODAY AS A LOW OVER
IOWA BEGINS TO OCCLUDE AND GRADUALLY FILL. ANTICIPATE BEING ABLE
TO CANCEL GALE WARNING EARLY FOR SOUTHERN LAKE MICHIGAN AND
NORTHERN PORTIONS SHOULD BE ABLE TO EXPIRE ON SCHEDULE THIS
EVENING. SFC LOW SHOULD WANDER AROUND IOWA THROUGH TOMORROW BEFORE
A MORE DECISIVE NORTHEASTERLY MOTION COMMENCES SATURDAY NIGHT. THE
LOW IS EXPECTED TO MOVE ACROSS NORTHERN PORTIONS OF THE LAKE EARLY
SUNDAY WITH MODEST WNW WINDS LOCKING IN BEHIND THE LOW. COLD FRONT
EXPECTED TO DROP DOWN THE LAKE MONDAY WITH RENEWED COLD AIR
ADVECTION AND TIGHTENING PRESSURE GRADIENT LEADING TO A FRESHENING
UP OF THE WINDS TO AROUND 30 KNOTS. FAIRLY QUICK DROP OFF IN WINDS
EXPECTED MONDAY NIGHT AS SURFACE RIDGE BUILDS EASTWARD ALLOWING
GRADIENT TO BEGIN RELAXING.

IZZI

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
     UNTIL 4 AM SATURDAY.

&&

Hazardous weather outlook, Dec 25, 4:37 PM CST, 9 hours 23 minutes before

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
437 PM CST FRI DEC 25 2009

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
262245-
WINNEBAGO-BOONE-MCHENRY-LAKE ILLINOIS-OGLE-LEE-DE KALB-KANE-
DUPAGE-COOK-LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-
IROQUOIS-FORD-LAKE INDIANA-PORTER-NEWTON-JASPER-BENTON-
437 PM CST FRI DEC 25 2009 /537 PM EST FRI DEC 25 2009/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

.DAY ONE...TONIGHT.

SOME LIGHT SNOW WILL OCCUR TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

SOME AREA RIVERS MAY RISE TO FLOOD STAGE THIS WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

LMZ740>745-262245-
WINTHROP HARBOR TO WILMETTE HARBOR-
WILMETTE HARBOR TO NORTHERLY ISLAND-
NORTHERLY ISLAND TO CALUMET HARBOR-CALUMET HARBOR TO GARY-
GARY TO BURNS HARBOR-BURNS HARBOR TO MICHIGAN CITY-
437 PM CST FRI DEC 25 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS NEARSHORE
WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE
MICHIGAN.

.DAY ONE...TONIGHT.

STRONG WINDS AND HIGH WAVES WILL LEAD TO HAZARDOUS CONDITIONS FOR
SMALL CRAFT ON THE ILLINOIS AND INDIANA NEAR SHORES TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-262245-
LAKE MICHIGAN FROM MICHIGAN CITY IN TO ST. JOSEPH MI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM SEUL CHOIX POINT TO ROCK ISLAND PASSAGE 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN SOUTH OF A LINE FROM SEUL CHOIX POINT TO THE
MACKINAC BRIDGE AND NORTH OF A LINE FROM CHARLEVOIX MI TO SOUTH
FOX ISLAND 5 NM OFFSHORE-
LAKE MICHIGAN FROM CHARLEVOIX TO POINT BETSIE MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM POINT BETSIE TO MANISTEE MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM ROCK ISLAND PASSAGE TO STURGEON BAY WI-
LAKE MICHIGAN FROM STURGEON BAY TO TWO RIVERS WI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM TOW RIVERS TO SHEBOYGAN WI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM SHEBOYGAN TO PORT WASHINGTON WI 5 NM OFFSHORE
TO MID LAKE-
LAKE MICHIGAN FROM PORT WASHINGTON TO NORTH POINT LIGHT WI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM NORTH POINT LIGHT TO WIND POINT WI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WIND POINT WI TO WINTHROP HARBOR IL 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WINTHROP HARBOR TO WILMETTE HARBOR IL 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WILMETTE HARBOR IL TO MICHIGAN CITY IN 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM PENTWATER TO MANISTEE MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM WHITEHALL TO PENTWATER MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM GRAND HAVEN TO WHITEHALL MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM HOLLAND TO GRAND HAVEN MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM SOUTH HAVEN TO HOLLAND MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM ST. JOSEPH TO SOUTH HAVEN MI 5 NM OFFSHORE TO
MID LAKE-
437 PM CST FRI DEC 25 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE OPEN WATERS OF LAKE
MICHIGAN.

.DAY ONE...TONIGHT.

GALE FORCE WINDS TO 35 KNOTS ARE LIKELY ON THE NORTH HALF OF LAKE
MICHIGAN.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

In the hours before

Local storm report, Dec 25, 8:31 PM CST, 5 hours 29 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
831 PM CST FRI DEC 25 2009

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0825 PM     SNOW             4 S OTTAWA              41.29N 88.83W
12/25/2009  M0.8 INCH        LA SALLE           IL   TRAINED SPOTTER

            AMOUNT OF NEW SNOW IN PAST 4 HOURS.

&&

ACS

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

9 winter storm. Local standard time, as filed.

Winter Storm, Winnebago

When: December 26, 2:00 AM CST to 10:00 PM CST
Where: Winnebago forecast zone
Reported by: Trained Spotter
Coordinates: 42.336, -89.161 (the zone’s center; the record gives no point)

Winter Storm, De Kalb

When: December 26, 2:00 AM CST to 7:00 PM CST
Where: De Kalb forecast zone
Reported by: Trained Spotter
Coordinates: 41.894, -88.770 (the zone’s center; the record gives no point)

Winter Storm, Boone

When: December 26, 2:00 AM CST to 10:00 PM CST
Where: Boone forecast zone
Reported by: Trained Spotter
Coordinates: 42.323, -88.823 (the zone’s center; the record gives no point)

Winter Storm, Kane

When: December 26, 3:00 AM CST to 7:00 PM CST
Where: Kane forecast zone
Reported by: Trained Spotter
Coordinates: 41.939, -88.429 (the zone’s center; the record gives no point)

Winter Storm, Kendall

When: December 26, 3:00 AM CST to 7:00 PM CST
Where: Kendall forecast zone
Reported by: Trained Spotter
Coordinates: 41.591, -88.429 (the zone’s center; the record gives no point)

Winter Storm, McHenry

When: December 26, 4:00 AM CST to 7:00 PM CST
Where: McHenry forecast zone
Reported by: Trained Spotter
Coordinates: 42.324, -88.452 (the zone’s center; the record gives no point)

Winter Storm, Du Page

When: December 26, 4:00 AM CST to 7:00 PM CST
Where: Du Page forecast zone
Reported by: Trained Spotter
Coordinates: 41.852, -88.086 (the zone’s center; the record gives no point)

Winter Storm, Cook

When: December 26, 4:00 AM CST to 7:00 PM CST
Where: Cook forecast zone
Reported by: Trained Spotter

Winter Storm, Lake

When: December 26, 6:00 AM CST to 7:00 PM CST
Where: Lake forecast zone
Reported by: Trained Spotter
Coordinates: 42.349, -87.862 (the zone’s center; the record gives no point)

What these are

Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Illinois in 2009 Every state in 2009 This day in weather history Warnings in Illinois, December 2009

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 204395, 204397, 204404, 204400, 204403, 204398, 204401, 204402, 204399.