Wyoming, 2002

Heavy Snow in Wyoming, March 12 to 13, 2002

March 12 to 13, 2002 · NWS RIW · 1 event in 1 county or zone

1 heavy snow, as filed by the National Weather Service.

Where it happened

Every event with a place to put it; 1 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
1

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 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, 1:57 PM MST, 6 hours 3 minutes earlier.

Area forecast discussion, Mar 12, 1:57 PM MST, 6 hours 3 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
157 PM MST TUE MAR 12 2002

THE 20Z SFC CHART SHOWS LOW PRESSURE OVER NE WY WITH HIGH PRESSURE
OVER ERN UT/WRN CO. SFC PRESSURE RISES ARE STRONGEST OVER SRN CANADA
WITH FRONT IN NRN MT. KRIW RADAR RETURNS OVER OVER THE WRN MTNS AND
THE BIG HORNS. SPOTTER FROM JAC REPORTING -RASN IN THE VALLEY. UP
TO 5 INCHES OF NEW SNOW HAS BEEN REPORTED IN THE MTNS. WATER VAPOR
IMAGERY SHOWING STEADY STREAM OF PACIFIC MSTR MOVING IN ZONAL FLOW
TOWARD WRN MTNS OF WY. TROUGH OVER THE NE PAC WAS PUSHING MSTR
SWATH TO THE SLOWLY SOUTH.

130KT JET IS PROGGED TO PUSH SOUTH TON. UNTIL THEN...THE NW REMAINS
IN THE LFG AND TOWARD MORNING AND ON WED THE SW IS IN THE LFQ. AS
THESE DYNAMICS SHIFT SOUTH OVERNIGHT...THE MTNS SHOULD PICKUP
MORE SUBSTANTIAL SNOWFALL. WEST WIND AT 25 TO 35 MPH OVER THE MTNS
SHOULD CONTINUE TO CAUSE SOME BLOWING AND DRIFTING SNOW. CURRENT
WINTER WEATHER ADVISORY FOR THE WRN MTNS LOOKS ON TRACK AND WILL KEEP
TON. LATER TON...FRONT IN NRN MT WILL PUSH SOUTH AND SHOULD MOVE INTO
CPR AND RIW TOWARD MORNING. UPSLOPE IS MAINLY SFC BASED SO ANY
SNOWFALL SHOULD BE LIGHT. DYNAMICS STRONG ENOUGH IN SW WED
TO CONSIDER POSSIBILITY OF AN ADVISORY BUT WARM TEMPS SHOULD LIMIT
AMOUNT OF ACCUMULATION AND WET SNOW SHOULD NOT BLOW AROUND MUCH. A
TROUGH APPROACHES WRN WY WED AFT WITH UVVS INDICATED EAST OF THE DIV.
NORTHWEST FLO/SUBSIDENCE TAKES OVER THU/THU NITE. CLOUDS INCR AGAIN
IN WEST FRI AS THE FLOW BECOMES ZONAL AGAIN. H7 TEMPS COOL DOWN TON
AS JET MOVES SOUTH.

CURRENT EXTENDED IS MOSTLY ON TRACK WITH THE NEW MRF RUN. ONE MORE
DAY OF SNOW LOOKS POSSIBLE IN THE FAR WEST AS A SECOND TROUGH IS
ADVERTIZED. THE FIRST TROUGH MOVES EAST OF THE DIVIDE SUN WITH THE
SECOND TROUGH EAST OF THE DIVIDE ON MON.  TUESDAY LOOKS RELATIVELY
DRY WITH NORTHWEST FLOW...DECREASING RH AND SURFACE HIGH PRESSURE
BUILDING IN FROM THE WEST. MAX/MIN TEMPS ARE RELATIVELY UNCHANGED
THROUGH THE PERIOD WITH H7 TEMPS NEARLY STEADY.

.RIW...WINTER WEATHER ADVISORY TONIGHT WY ZNS 1..2..3..6..
       17..19.

FS

The radar

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

Open the radar archive at this moment

Event by event

1 heavy snow. Local standard time, as filed.

Heavy Snow, Cody Foothills / Part of E Park

When
March 12, 8:00 PM MST to March 13, 4:00 AM MST
Where
Cody Foothills / Part of E Park forecast zone
Reported by
GENERAL PUBLIC
Coordinates
44.524, -108.791 (the zone’s center; the record gives no point)

A cold front dropped south into the Big Horn Basin, while moist Pacific air moved east across the area. Bands of heavier snow dropped 6 to 8 inches of snow from around Cody north to the Montana border. Clark reported the heaviest snowfall with 8 inches. The brief heavy snow caused road closures north of Cody and suspended operations at the Yellowstone Regional Airport for over 4 hours.

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: 5281371.