Dense Fog in Illinois, March 31, 2001

Name: Dense Fog in Illinois, March 31, 2001
Start: 2001-03-31T00:01
End: 2001-03-31T08:30
Location: Illinois

March 31, 2001 · NWS PAH · 19 events in 19 counties and zones

Widespread dense fog formed around midnight. During the early morning hours, visibility was below a quarter mile.

Where it happened

Every event with a place to put it; 19 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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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: 19

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 PAH wrote it up.

Widespread dense fog formed around midnight. During the early morning hours, visibility was below a quarter mile. One fatal accident was attributed to the fog. An elderly man driving east on Illinois 146 in Hardin County failed to stop where the road ends at Illinois Route 1. His vehicle struck a stone wall. The accident occurred at 7:15 A.M. The fog lifted between 8 and 9 A.M.

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 Paducah, KY wrote its last area forecast discussion before the first event at Mar 30, 2:00 PM CST, 10 hours 1 minute earlier.

Area forecast discussion, Mar 30, 2:00 PM CST, 10 hours 1 minute before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
200 PM CST FRI MAR 30 2001

LATEST 19Z WATER VAPOR IMAGERY AND RUC 500 MB HEIGHTS INDICATE A
SHORTWAVE TROUGH FROM CENTRAL MISSOURI TO MID TENNESSEE. KPAH/KSGF
RADARS SHOW THE SOUTHERN EDGE OF THE RAIN LIFTING NORTHEAST WITH THE
SHORTWAVE. THIS TREND SHOULD CONTINUE THIS EVENING...WITH ONLY SOME
LINGERING DRIZZLE OR PATCHY -RA BY 00Z.

MAIN CONCERN FOR TONIGHT IS OF THE AVIATION VARIETY...LOW CLOUDS AND
FOG POTENTIAL. LOW LEVELS HAVE BEEN SATURATED BY 12 TO 18 HOURS OF
RAIN ACROSS THE REGION. WEAK SURFACE RIDGING WILL BECOME ESTABLISHED
OVER THE FA TONIGHT...WHICH SHOULD TRAP MUCH OF THE LOW STRATUS THAT
EXISTS.

NGM/AVN/ETA ARE IN EXCELLENT AGREEMENT WITH THE TIMING OF THE COLD
FRONT LATE SATURDAY...TAKING IT ACROSS SE MISSOURI BY 00Z...AND THEN
ACROSS WEST KENTUCKY AND SW INDIANA BETWEEN 00Z AND 06Z. MODELS SHOW
A NARROW BAND OF 700 MB UPWARD MOTION AND DEEP MOISTURE CO-LOCATED
WITH THE SFC FRONT. SEVERE CONVECTIVE POTENTIAL WILL BE LIMITED BY A
COUPLE OF PARAMETERS. BOUNDARY LAYER WINDS WILL BE SLOW TO BACK INTO
THE SOUTHWEST SATURDAY...SO LOW LEVEL MOISTURE RETURN WILL BE VERY
LIMITED...WITH SFC DEW POINTS STRUGGLING TO REACH 50. IN
ADDITION...CONSIDERABLE CLOUD COVER WILL LIMIT DESTABILIZATION.
EXPECT A BAND OF SHOWERS AND GENERAL THUNDER TO ACCOMPANY THE FRONT
ACROSS THE FA.

AFTER THE PASSAGE OF THE COLD FRONT SATURDAY NIGHT...THE UPPER LOW
WILL CLOSE OFF AS IT DROPS SOUTHEAST ACROSS THE MID MISSISSIPPI
VALLEY. MODEL SOUNDINGS INDICATE MOISTURE WILL BE VERY LIMITED
BEHIND THE COLD FRONT. COULD NOT RULE OUT SOME FLURRIES WITH THE
UPPER LOW LATE SATURDAY NIGHT INTO EARLY SUNDAY.

GUSTY WINDS AND COLDER TEMPERATURES WILL BE THE STORY SUNDAY.
WRAPAROUND CLOUDINESS WILL BE MOST EXTENSIVE NORTH AND EAST OF PAH
AS LOW PASSES WELL TO OUR EAST. STEEP LOW LEVEL LAPSE
RATES...TYPICAL FOR A SPRING AFTERNOON...WILL MIX SOME STRONGER
GUSTS DOWN TO THE SURFACE.

THE EXTENDED FORECAST APPEARS WARMER BASED ON NEW AVN/MRF GUIDANCE.
UPPER RIDGE WILL BUILD OVER THE REGION EARLY IN THE WEEK...FOLLOWED
BY SOUTHWEST FLOW BY MID WEEK. HIGHS SHOULD FINALLY GO ABOVE NORMAL
BY MID WEEK. EMBEDDED SHORTWAVES IN THE SOUTHWEST FLOW WILL BRING
SOME MOISTURE MID TO LATTER PART OF THE WEEK.

.PAH...NONE.

MY

The radar

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

Open the radar archive at this moment

Event by event

19 dense fog. Local standard time, as filed.

Dense Fog, Alexander

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Alexander forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.192, -89.338 (the zone’s center; the record gives no point)

Dense Fog, Edwards

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Edwards forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 38.417, -88.053 (the zone’s center; the record gives no point)

Dense Fog, Franklin

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Franklin forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.992, -88.924 (the zone’s center; the record gives no point)

Dense Fog, Gallatin

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Gallatin forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.763, -88.230 (the zone’s center; the record gives no point)

Dense Fog, Hamilton

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Hamilton forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 38.082, -88.539 (the zone’s center; the record gives no point)

Dense Fog, Hardin

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Hardin forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.518, -88.267 (the zone’s center; the record gives no point)

Dense Fog, Jackson

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Jackson forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.785, -89.382 (the zone’s center; the record gives no point)

Dense Fog, Jefferson

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Jefferson forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 38.301, -88.924 (the zone’s center; the record gives no point)

Dense Fog, Johnson

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Johnson forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.460, -88.881 (the zone’s center; the record gives no point)

Dense Fog, Massac

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Massac forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.219, -88.708 (the zone’s center; the record gives no point)

Dense Fog, Perry

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Perry forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 38.084, -89.367 (the zone’s center; the record gives no point)

Dense Fog, Pope

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Pope forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.413, -88.562 (the zone’s center; the record gives no point)

Dense Fog, Pulaski

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Pulaski forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.223, -89.127 (the zone’s center; the record gives no point)

Dense Fog, Saline

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Saline forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.753, -88.541 (the zone’s center; the record gives no point)

Dense Fog, Union

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Union forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.471, -89.255 (the zone’s center; the record gives no point)

Dense Fog, Wabash

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Wabash forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 38.446, -87.844 (the zone’s center; the record gives no point)

Dense Fog, Wayne

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Wayne forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 38.430, -88.426 (the zone’s center; the record gives no point)

Dense Fog, White

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: White forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 38.088, -88.180 (the zone’s center; the record gives no point)

Dense Fog, Williamson

When: March 31, 12:01 AM CST to 8:30 AM CST
Where: Williamson forecast zone
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 37.730, -88.930 (the zone’s center; the record gives no point)

What these are

Dense Fog: Fog reducing visibility to a quarter mile or less, filed where it caused accidents or disruption.

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

The same day elsewhere

Every storm in Illinois in 2001 Every state in 2001 This day in weather history Warnings in Illinois, March 2001

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: 5236054, 5236055, 5236056, 5236057, 5236058, 5236059, 5236060, 5236061, 5236062, 5236063, 5236064, 5236065, 5236066, 5236067, 5236068, 5236069, 5236070, 5236071, 5236072.