Wyoming, 2003

Heavy Snow in Wyoming, May 1, 2003

May 1, 2003 · NWS BYZ · 1 event in 1 county or zone

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

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 Billings, MT wrote its last area forecast discussion before the first event at May 1, 3:25 AM MST, 3 hours 35 minutes earlier.

Area forecast discussion, May 1, 3:25 AM MST, 3 hours 35 minutes before
SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
425 AM MDT THU MAY 01 2003

.SHORT TERM...VALID FOR TDY AND FRI...

...WILL CONTINUE HEAVY SNOW WARNING FOR NORTHEAST BIG HORN MOUNTAINS
THROUGH NOON...

UPPER ENERGY CONTINUES TO SPIN OVER WYOMING/MONTANA BORDER THIS
MORNING...BRINGING RAIN TO LOWER LEVELS AND SNOW TO AROUND 5000 FEET
IN SOUTHERN ZONES. AVN HAS INITIALIZED BEST WITH THE ENERGY. RAIN AND
SNOW SHOULD HANG ON THROUGH AT LEAST 18Z. WILL KEEP 100 POPS IN UNTIL
THEN AND START TO DECREASE THINGS IN THE AFTERNOON. ETA STILL BRINGS
SOME INSTABILITY INTO WESTERN ZONES THIS AFTERNOON...BUT NOT AS MUCH
NOR AS FAR EAST AS YESTERDAY. WILL LOWER TEMPS A BIT IN SOUTHERN CLOUD
COVERED ZONES. WILL ALSO HAVE SOME ACCUMULATIONS MENTIONED IN SHR AND
RED LODGE FOR THIS MORNING.

FRIDAY...SOUTHWEST FLOW OPENS UP DRYING OUT ATMOSPHERE. SHOULD
ACTUALLY SEE THE SUN AND WILL DECREASE CLOUD COVER FORECAST ACROSS THE
AREA. ETA SHOWING SOME INSTABILITY WITH A WAVE THAT MOVES ACROSS
EASTERN MONTANA FROM 18Z ON. BUT VERY LITTLE DYNAMICS OR MOISTURE TO
WORK WITH...SO WILL KEEP IT DRY IN EAST FOR NOW. GOING FORECAST LOOKS
GOOD. RASCH

.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MODELS CONTINUE TO BE CONSISTENT IN KEEPING SOUTHWEST FLOW ALOFT OVER
THE FORECAST AREA THROUGH LATE IN THE DAY ON SATURDAY AHEAD OF A LARGE
UPPER TROUGH...ALONG WITH ABUNDANT MOISTURE AND SHORTWAVE ENERGY. TIMING
OF SHORTWAVE ENERGY A LITTLE SLOWER WITH THE LATEST MODEL RUNS RESULTING
IN PRECIP CHANCES HOLDING OFF UNTIL THE AFTERNOON HOURS. HAVE ADJUSTED
POPS TO REFLECT THIS. UPPER TROUGH BECOMES NEGATIVELY TILTED SUNDAY AND
REMAINS OVER THE FORECAST AREA THROUGH EARLY TUESDAY WHEN WEAK UPPER
RIDGE BEGINS TO MOVE IN. A WEAK FRONTAL SYSTEM STILL PROGGED TO MOVE
THROUGH THE AREA ON SUNDAY WITH INCREASING WINDS AND COOLER AIR MOVING
INTO SOUTHERN MONTANA. SHOWERS STILL A POSSIBILITY WITH CHANCE FOR
THUNDER STILL LIMITED SO WILL CONTINUE TO LEAVE THUNDER WORDING OUT AT
THIS TIME. PREVIOUSLY MENTIONED UPPER RIDGE OVER THE AREA LATE TUESDAY
THROUGH WEDNESDAY RESULTING IN DRIER CONDITIONS TUESDAY THAN GOING
FORECAST SO HAVE BACKED OFF ON POPS. TEMPERATURES ON TRACK FOR THE MOST
PART AND ONLY MADE SOME MINOR CHANGES. MACZKO

    TDY FRI     SAT     SUN     MON     TUE     WED
-------------------------------------------------------
BIL 052 041/066 043/068 043/058 040/054 041/056 037/059
    +/T 22/T    23/T    33/W    34/W    40/E    00/E
LVM 056 038/062 039/064 040/059 036/053 034/055 030/055
    8/T 22/T    23/T    33/W    34/O    43/W    30/E
HDN 055 041/064 042/069 043/059 039/054 040/056 036/060
    9/R 02/T    23/T    33/W    34/W    40/E    00/E
MLS 063 040/073 042/072 042/059 042/058 041/060 037/062
    0/B 00/B    03/T    33/W    33/W    30/E    00/E
4BQ 052 039/066 042/071 041/057 042/054 039/057 035/059
    9/R 02/T    23/T    33/W    33/W    30/E    00/E
BHK 061 038/071 040/071 040/056 042/055 039/059 035/058
    0/B 00/B    03/T    33/W    33/W    30/E    00/E
SHR 054 028/062 036/065 041/057 037/051 038/053 034/056
    +/O 02/T    23/T    33/W    34/W    43/W    30/E

.BYZ...
MT...NONE.
WY...HEAVY SNOW WARNING THROUGH NOON FOR ZONE WYZ098.
Hazardous weather outlook, May 1, 3:30 AM MST, 3 hours 30 minutes before
MTZ028>042-056>058-WYZ098-099-021100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BILLINGS MT
430 AM MDT THU MAY 1 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL...SOUTHEAST
MONTANA AND NORTH CENTRAL WYOMING.

.DAY ONE...
A STORM SYSTEM ALONG THE MONTANA AND WYOMING BORDER WILL SLOWLY
DECREASE IN INTENSITY TODAY. BEFORE IT DOES...SNOW WILL CONTINUE
ABOVE 5000 FEET OVER SOUTHERN MONTANA AND IN SHERIDAN COUNTY
WYOMING. SNOW WILL BE HEAVY AT TIMES THIS MORNING IN THE NORTHEAST
BIG HORN MOUNTAINS...WITH AN ADDITIONAL 2 TO 4 INCHES OF SNOW
ACCUMULATION. STORM TOTAL ACCUMULATIONS ARE EXPECTED TO RANGE FROM 8
TO 14 INCHES.

.DAYS TWO THROUGH SEVEN...
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

WCJIN-WYNW-WYNE

Event by event

1 heavy snow. Local standard time, as filed.

Heavy Snow, Northeast Bighorn Mountains

When
May 1, 7:00 AM MST
Where
Northeast Bighorn Mountains forecast zone
Reported by
TRAINED SPOTTER

8 inches of snow at Arrowhead Lodge

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 2003Every state in 2003This day in weather historyWarnings in Wyoming, May 2003

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: 5350397.