Winter Storm, S Sierra Mtns
- When
- May 1, 4:00 PM PST to May 2, 2:30 AM PST
- Where
- S Sierra Mtns forecast zone
- Reported by
- Park/Forest Service
Winter Storm and Winter Weather in California, May 1 to 2, 2009
May began with a strong upper-level trough moving into California, bringing locally heavy showers to the region. The trough tapped into a deep fetch of subtropical moisture, resulting in high snow levels above 9000 feet for much of the event, and ultimately no lower than 8200 feet.
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 HNX wrote it up.
May began with a strong upper-level trough moving into California, bringing locally heavy showers to the region. The trough tapped into a deep fetch of subtropical moisture, resulting in high snow levels above 9000 feet for much of the event, and ultimately no lower than 8200 feet. Fresno received 0.40 inch of rain on May 1st, more than the normal of 0.39 inch for the entire month. Bakersfield received nearly as much, with the rain gauge at Meadows Field measuring 0.35 inch; the normal for the month of May at Bakersfield is 0.24 inch. In the Southern Sierra Nevada, Yosemite Valley received just over 2 inches of rain, and over 1.8 inch of rain fell as far south as Lodgepole in Sequoia National Park. In the high country of the Southern Sierra Nevada, snow did fall, with up to 15 inches at Upper Burnt Corral (9,700 feet). The rain tapered off on May 2nd, as a weak short-wave move through the region behind the main trough, and only a few showers lingered into the 3rd.
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 Hanford, CA wrote its last area forecast discussion before the first event at May 1, 2:14 PM PST, 1 hour 46 minutes earlier.
Area forecast discussion, May 1, 2:14 PM PST, 1 hour 46 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 314 PM PDT FRI MAY 1 2009 .DISCUSSION...THE UPPER LOW NEAR 39N/130W IS NEGATIVELY TILTED WITH THE UPPER JET UNDER CUTTING IT. WATER VAPOR IMAGERY INDICATE A GOOD SWATH OF MOISTURE WITH THIS SYSTEM. THE LEADING EDGE OF THIS SYSTEM IS BEGINNING TO SPREAD INTO THE CWFA WITH MAINLY LIGHT RAIN SO FAR. EXPECT RAIN TO INCREASE IN COVERAGE AND INTENSITY THROUGH THE EVENING HOURS WITH THE GREATEST AMOUNTS OF RAIN BETWEEN 00Z AND 15Z (5 PM TONIGHT THROUGH 8 AM SATURDAY). SNOW LEVELS WILL START OUT HIGH...BUT WILL LOWER TO NEAR 6500 FEET TOWARD MORNING. WINTER WEATHER WARNINGS AND ADVISORIES REMAIN IN EFFECT FOR THE SIERRA NEVADA ZONES ABOVE 7000 FEET. RAINFALL AMOUNTS STILL LOOK ON TRACK FOR 1-2 INCHES IN THE SIERRA NEVADA AND AS MUCH AS ONE HALF INCH IN THE NORTHERN HALF OF THE SAN JOAQUIN VALLEY...TO A QUARTER OF AN INCH IN THE SOUTH. THE HEAVY RAIN AND HIGH SNOW LEVELS NEAR YOSEMITE WILL CAUSE THE MERCED RIVER TO RISE RAPIDLY WITH FLOODING PROBABLE ALONG THE MERCED RIVER IN YOSEMITE PARK. THE MAIN TROUGH WILL EXIT THE AREA BY SATURDAY AFTERNOON WITH SOME RESIDUAL SHOWERS...ESPECIALLY IN THE MOUNTAINS. ON SUNDAY ANOTHER SYSTEM MOVES ACROSS NORTHERN CALIFORNIA CONTINUING A CHANCE OF RAIN NORTH OF FRESNO. ALTHOUGH LOW AMPLITUDE RIDGING TRIES TO BUILD OVER CENTRAL CALIFORNIA MONDAY AND TUESDAY...IT IS HAMPERED SOMEWHAT BY SYSTEMS THAT CONTINUE TO MOVE ACROSS NORTHERN CALIFORNIA. THIS WILL KEEP A SLIGHT CHANCE OF SHOWERS ACROSS THE NORTHERN THIRD OF THE CWFA...WITH THE BEST CHANCE NEAR YOSEMITE MONDAY AND TUESDAY. ELSEWHERE IN THE CWFA THE WEATHER WILL DRY OUT AND TEMPERATURES WILL WARM. WEDNESDAY AND THURSDAY LOOK DRY AND WARMER ACROSS THE ENTIRE CENTRAL CALIFORNIA INTERIOR. && .AVIATION...A PACIFIC STORM SYSTEM OFF THE COAST WILL MOVE INTO CALIFORNIA THIS EVENING. WHILE LOCAL IFR CONDITIONS MAY BE SEEN OVER THE HIGHER TERRAIN OF THE SIERRA NEVADA...CONDITIONS OVER THE LOWER FOOTHILLS AND SAN JOAQUIN VALLEY ARE EXPECTED TO REMAIN AT VFR/MVFR LEVELS THROUGH 06Z SATURDAY. MORE WIDESPREAD MOUNTAIN OBSCURATIONS AND VALLEY MVFR CONDITIONS MAY BE SEEN AFTER 06Z SATURDAY. && .AIR QUALITY ISSUES... NO AIR QUALITY ISSUES TODAY THIS IS ALSO AIR QUALITY AWARENESS WEEK. MORE INFORMATION IS AVAILABLE IN THE LATEST PUBLIC INFORMATION STATEMENT FROM THE NATIONAL WEATHER SERVICE OFFICE IN HANFORD. SEE /NOUS89 KHNX/ OR /SFOPNSHNX/ FOR DETAILS YOU CAN MAKE A DIFFERENCE IN AIR QUALITY IN THE SAN JOAQUIN VALLEY. BRING YOUR LUNCH TO WORK OR WALK TO A NEARBY RESTAURANT. FOR MORE INFORMATION VISIT HEALTHYAIRLIVING.COM OR VALLEYAIR.ORG && .HNX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 10 AM PDT SATURDAY FOR CAZ097. WINTER STORM WARNING UNTIL 10 AM PDT SATURDAY FOR CAZ096. FLOOD WARNING FOR LATE TONIGHT UNTIL FURTHER NOTICE. FOR THE MERCED RIVER AT POHONO BRIDGE. && PUBLIC...BEAN AVN/FW...MOLINA WEATHER.GOV/HANFORD
Hazardous weather outlook, May 1, 9:30 AM PST, 6 hours 30 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 1030 AM PDT FRI MAY 1 2009 CAZ096-021200- SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON- 1030 AM PDT FRI MAY 1 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SOUTHERN SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON. .DAY ONE...TODAY AND TONIGHT A WINTER STORM WARNING FOR HEAVY SNOW AT ELEVATIONS ABOVE 7000 FEET...REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON TO 10 AM PDT SATURDAY FOR THE SOUTHERN SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON. FOR FURTHER DETAILS PLEASE REFER TO THE LATEST WINTER WEATHER MESSAGE /WWUS46 KHNX/ OR SFOWSWHNX/. A FLOOD WARNING IS IN EFFECT FOR THE MERCED RIVER AT POHONO BRIDGE. FOR MORE DETAILED INFORMATION PLEASE REFER TO THE LATEST RIVER FLOOD STATEMENT SFOFLWUSJ /WGUS46 KHNX/. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE WINTER STORM WARNING FOR HEAVY SNOW AT ELEVATIONS ABOVE 7000 FEET REMAINS IN EFFECT UNTIL 10 AM PDT SATURDAY. THE FLOOD WARNING REMAINS IN EFFECT FOR THE MERCED RIVER AT POHONO BRIDGE UNTIL FURTHER NOTICE...OR UNTIL THE FLOOD WARNING IS CANCELED. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED. WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE. WEATHER.GOV/HANFORD CAZ097-021200- TULARE COUNTY MOUNTAINS- 1030 AM PDT FRI MAY 1 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE TULARE COUNTY MOUNTAINS. .DAY ONE...TODAY AND TONIGHT A WINTER WEATHER ADVISORY FOR SIGNIFICANT SNOW AT ELEVATIONS ABOVE 7000 FEET IS IN EFFECT FROM 5 PM THIS AFTERNOON TO 10 AM PDT SATURDAY FOR THE SOUTHERN SIERRA NEVADA FROM KINGS CANYON TO THE KERN COUNTY LINE. PLEASE REFER TO THE LATEST WINTER WEATHER MESSAGE /WWUS46 KHNX/ OR /SFOWSWHNX/ FOR FURTHER DETAILS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE WINTER WEATHER ADVISORY FOR SIGNIFICANT SNOW AT ELEVATIONS ABOVE 7000 FEET REMAINS IN EFFECT UNTIL 10 AM PDT SATURDAY. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED. WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE. BSO WEATHER.GOV/HANFORD
Event by event
1 winter storm, 1 winter weather. Local standard time, as filed.
Winter Weather, Tulare Cty Mtns
- When
- May 1, 4:00 PM PST to May 2, 2:30 AM PST
- Where
- Tulare Cty Mtns forecast zone
- Reported by
- Park/Forest Service
What these are
- Winter Storm
- A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
- Winter Weather
- Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Flash Flooding and Flood in Oklahoma, May 1 to 2, 2009
- Tornadoes and Hail in Alabama, May 1 to 3, 2009
- Tornadoes and Flash Flooding in Tennessee, May 1, 2009
- Drought in Texas, May 1 to 31, 2009
- Flooding in Arkansas, May 1 to 31, 2009
- Tornadoes and Flash Flooding in Arkansas, May 1 to 3, 2009
- Flooding in Illinois, May 1 to 4, 2009
- Flood in Iowa, May 1 to 7, 2009
- Flood in Iowa, May 1, 2009
- Flash Flooding and Hail in Arkansas, May 1, 2009
- Flash Flooding and Flooding in Alabama, May 1 to 2, 2009
- Flooding in Indiana, May 1 to 29, 2009
More
Every storm in California in 2009Every state in 2009This day in weather historyWarnings in California, May 2009
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: 176463, 176464.