This low pressure system affected southeast Arizona from December 10th through the morning of the 13th. The storm originated over the Gulf of Alaska and dropped into southeast California on the morning of the 10th.
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.
The episode as NWS TWC wrote it up.
This low pressure system affected southeast Arizona from December 10th through the morning of the 13th. The storm originated over the Gulf of Alaska and dropped into southeast California on the morning of the 10th. This brought 40 to 50 mph wind gusts through all portions of county warning area except western Pima county. On the 11th, heavy precipitation began as the short wave moved across southern Arizona. Mountain snowfall rates increased to 3 inches per hour and snow levels dropped to 3000 feet. Rain and snow showers continued through various periods on the 12th. The snow finally stopped by late evening on the 12th, but frost and black ice developed over the bridges on the morning of the 13th causing traffic problems in the greater Tucson area.
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 Tucson, AZ wrote its last area forecast discussion before the first event at Dec 11, 2:35 AM MST, 5 hours 25 minutes earlier.
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 235 AM MST TUE DEC 11 2001 .SYNOPSIS...A STORM SYSTEM WILL MOVE ACROSS SOUTHERN ARIZONA TODAY BRINGING MUCH COOLER TEMPERATURES AND VALLEY RAIN AND MOUNTAIN SNOW TO SOUTHEAST ARIZONA. TWO OTHER DISTURBANCES WILL MOVE INTO SOUTHERN ARIZONA...ONE TONIGHT AND THE OTHER WEDNESDAY...CONTINUING THE CHANCE OF VALLEY SHOWERS AND MOUNTAIN SNOW SHOWERS. A COOL NORTHWEST FLOW ALOFT WILL BE OVER THE AREA FOR THE REMAINDER OF THE WEEK...KEEPING TEMPERATURE BELOW NORMAL. WARMER TEMPERATURES ARE THEN EXPECTED OVER THE UPCOMING WEEKEND. .DISCUSSION...STORM SYSTEM CURRENTLY CENTERED NEAR YUMA..WITH AREA OF PRECIPITATION OUT AHEAD OF IT OVER PORTIONS OF WESTERN AND CENTRAL PIMA COUNTY. SOME LIGHTNING STRIKES ALSO NOTED WITH THIS AREA OF PRECIPITATION. THIS SYSTEM HAS INCORPORATED SOME LOW LEVEL MOISTURE INTO IT AS INDICATED BY SAN DIEGOS 00Z SOUNDING...WHICH SHOWS A MARINE LAYER DEPTH TO NEAR 8000 FEET. IN ADDITION...GOOD LIFT AND VERY COLD TEMPERATURES ALOFT WILL HELP WRING OUT ALL AVAILABLE MOISTURE AS IT TRACKS EAST ACROSS SOUTHERN ARIZONA TODAY. THICKNESS SUPPORT SNOW LEVELS DOWN TO 4500 FEET TODAY. WILL CONTINUE SNOW ADVISORY TODAY FOR ALL ZONES EXCEPT FAR WESTERN PIMA COUNTY ABOVE 4500 FEET. ANOTHER VORT MAX WILL SLIDE SOUTHEAST INTO SOUTHERN ARIZONA TONIGHT IN NORTHWEST FLOW ALOFT. WITH MOISTURE ALREADY IN PLACE...WILL CONTINUE THE A CHANCE OF VALLEY SHOWERS AND MOUNTAIN SNOW SHOWERS FOR MUCH OF THE CWA...THE EXCEPTION BEING FAR WESTERN PIMA COUNTY WHICH WILL BE ON THE BACK SIDE OF THE VORT MAX. WILL KEEP SNOW LEVELS AT 4500 FEET...HOWEVER SNOW MAY BRIEFLY COME DOWN AS LOW AS 4000 FEET BEFORE TAPERING OFF. QPF AMOUNTS SHOULD BE AROUND ONE THIRD OF AN INCH IN THE VALLEYS AND THE FORECAST OF 3 TO 8 INCHES IN THE MOUNTAINS ABOVE 4500 FEET LOOKS GOOD EVERYWHERE EXCEPT THE WHITE MOUNTAINS WHERE I WILL BUMP UP 24 HOUR TOTAL AMOUNTS INTO THE 5 TO 10 INCH RANGE. YET ANOTHER DISTURBANCE MOVES INTO SOUTHERN ARIZONA WEDNESDAY. ALTHOUGH THE MODELS ARE IN GENERAL AGREEMENT WITH THE TIMING AND POSITION OF THIS DISTURBANCE...THE MODELS DIFFER ON THE AMOUNT OF AVAILABLE MOISTURE...WITH ETA BEING MUCH DRIER THAN THE AVN. HOWEVER WITH GOOD DYNAMICS...WILL ADD SLIGHT CHANCE WORDING TO WEDNESDAYS FORECAST. WITH COLDER OVERNIGHT LOWS TONIGHT AND WEDNESDAY NIGHT... AREAS OF FROST WILL BE POSSIBLE. FOR THE LATTER FORECAST PERIODS...COOL NORTHWEST FLOW CONTINUES INTO THE WEEKEND...WITH TEMPERATURES REMAINING BELOW SEASONAL NORMS. MODELS CONTINUE TO FLIP FLOP ON TIMING AND STRENGTH OF THE TROUGH EXPECTED OVER THE WEEKEND...THEREFORE HAVE KEEP CURRENT EXTENDED FORECAST IN PLACE. ZELL .TWC...SNOW ADVISORY TODAY ABOVE 4500 FEET ALL ZONES XCPT ZONE 31.
1 heavy snow. Local standard time, as filed.
Hannagan Meadow received 20 inches of snow. Blue school received 5 inches and Rose Peak received 3 to 5 inches of snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2001Every state in 2001This day in weather historyWarnings in Arizona, December 2001
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: 5276387.