Wyoming, 2002

Heavy Snow in Wyoming, March 13 to 14, 2002

March 13 to 14, 2002 · NWS RIW · 2 events in 2 counties and zones

A strong cold front moved quickly south through the eastern plains of Wyoming. Upslope flow behind the front was responsible for 6 to 12 inches of snowfall in Buffalo and Casper.

Where it happened

Every event with a place to put it; 2 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

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
2

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 RIW wrote it up.

A strong cold front moved quickly south through the eastern plains of Wyoming. Upslope flow behind the front was responsible for 6 to 12 inches of snowfall in Buffalo and Casper. Snowfall of one foot or more was reported on Casper Mountain south of the city of Casper.

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 Riverton, WY wrote its last area forecast discussion before the first event at Mar 12, 11:40 PM MST, 2 hours 20 minutes earlier.

Area forecast discussion, Mar 12, 11:40 PM MST, 2 hours 20 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1140 PM MST TUE MAR 12 2002

FRONTAL BOUNDARY HAS MADE ITS WAY THROUGH THE BIG HORN BASIN AND
THROUGH MUCH OF NATRONA COUNTY AT 06Z. LOW CLOUDS AND LIGHT SNOW
FALLING OVER THE EASTERN PLAINS BEHIND THE FRONT. HOWEVER IN THE
BIG HORN BASIN...PACIFIC MOISTURE IS OVERRUNNING THE COLD AIR MASS
AND FAVORABLE LEFT EXIT REGION OF 300MB JET IS IN THE VICINITY. THIS
IS HELPING TO PRODUCE SNOW IN ZNS 4 AND 5...ESPECIALLY OVER THE
NORTHERN HALF OF THESE ZONES. REPORTS AT 03Z INDICATED LITTLE IF
ANY ACCUMULATION IN CODY AND DEAVER. BY 0545Z...CALLS TO THE PARK
AND BIG HORN COUNTY SHERIFFS INDICATED AMOUNTS WERE IN THE 3 TO 5
INCH RANGE WITH HAZARDOUS ROAD CONDITIONS. THUS....WITH RADAR SHOWING
THAT WESTERLY FETCH WILL LIKELY CONTINUE FOR THE NEXT 2-3 HOURS...
HAVE ISSUED A HEAVY SNOW WARNING FOR ZNS 4 AND 5 AND AN ADVISORY FOR
THE WESTERN BIG HORN MOUNTAINS.

.RIW...WINTER WEATHER ADVISORY OVERNIGHT WY ZNS 1/2/3/6/17/19/26.
    ...HEAVY SNOW WARNING OVERNIGHT WY ZNS 4/5.

The radar

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

Open the radar archive at this moment

Event by event

2 heavy snow. Local standard time, as filed.

Heavy Snow, East Johnson

When
March 13, 2:00 AM MST to March 14, 4:00 PM MST
Where
East Johnson forecast zone
Reported by
GENERAL PUBLIC
Coordinates
41.660, -108.879 (the zone’s center; the record gives no point)

Heavy Snow, Natrona / Natrona Except X Se

When
March 13, 2:00 AM MST to March 14, 4:00 PM MST
Where
Natrona / Natrona Except X Se forecast zone
Reported by
GENERAL PUBLIC
Coordinates
42.904, -109.273 (the zone’s center; the record gives no point)

What these are

Heavy Snow
Snowfall reaching the local warning threshold without the other hazards of a winter storm.

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

The same day elsewhere

More

Every storm in Wyoming in 2002Every state in 2002This day in weather historyWarnings in Wyoming, March 2002

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: 5281373, 5281374.