Jody Radzik
EF2
Along with everything happening in the big Alley, California's little "alley" has produced a few tornadoes of its own, today.
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2011-05-25 MISC: CA
- Thread starter Jody Radzik
- Start date
Along with everything happening in the big Alley, California's little "alley" has produced a few tornadoes of its own, today.
R R Smith
EF0
An unseasonably strong cold front moved through Northern California and spawned yet another series of post frontal tornadoes in the northern Sacramento Valley. All the ingredients were in place: an area of good surface convergence, a super cold 50 knot SW 500 flow, 500 CAPE and backed surface winds to produce a couple of low topped (25,000 ft) supercells which spawned a series of weak tornadoes. Chico airport reported SSE winds at 20 gusting to 27 during the tornado warning. The SAC NWS Local Storm Report lists 7 tornadoes however it may be downgraded to 3 or possibly 4 once assessment has been completed. Here's a link to some cool news helicopter footage: http://www.nbcbayarea.com/news/local/122635064.html
I was chasing yesterday but elected to stay in north central Siskiyou County... hoping for a photogenic thunderstorm or two. In spite of steep lapse rates and good bulk shear, the sun never really showed here... and I chased the Chico tornadoes on GR. By the way, the 19 z HRRR model nailed the tornadic cells in the northern Sac Valley.
I was chasing yesterday but elected to stay in north central Siskiyou County... hoping for a photogenic thunderstorm or two. In spite of steep lapse rates and good bulk shear, the sun never really showed here... and I chased the Chico tornadoes on GR. By the way, the 19 z HRRR model nailed the tornadic cells in the northern Sac Valley.
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R R Smith
EF0
More from NWS Sacramento:
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
945 PM PDT WED MAY 25 2011
.DISCUSSION...
BUSY DAY TODAY THAT IS WINDING DOWN. A NUMBER OF TORNADO
SITINGS TODAY OVER GLEN AND BUTTE COUNTIES THAT STARTED SHORTLY
AFTER 5 PM. FOUR DISTINCT CELLS PRODUCED MULTIPLE TORNADOES TODAY.
THERE IS CURRENTLY A COUPLE OF PEOPLE IN THE AREA DOING A STORM
SURVEY...BUT FROM A PRELIMINARY LOOK BACK AT DOPPLER RADAR THERE
WERE FOUR DISTINCT AREAS WHERE TORNADOES WHERE INDICATED. ONE
DECENT CELL THAT PRODUCING HAIL AND HEAVY RAIN AND LIGHTING SPLIT
AFTER IT CROSSED THE I-5 NEAR ARTOIS. TWO DISTINCT CELLS PRODUCING
TORNADOES DEVELOPED WITH ONE CELL MOVING JUST NORTH OF ORD BEND AND
ONE TO THE SOUTHERN END OF ORD BEND.
A LITTLE AFTER 6 PM THE SOUTHERN CELL SPLIT PRODUCING ANOTHER
TORNADO. ALSO TO THE EAST OF CHICO ONE FORMED...SO AT THIS TIME
THERE WAS FOUR CELLS ONE TO THE EAST OF CHICO...ONE SOUTH OF
CHICO...ONE NEAR DAYTON AND ONE NEAR DURHAM. THE SOUTHERN TWO CELLS
STAYED TOGETHER THE LONGEST BEFORE DECREASING IN INTENSITY BY 7:30
PM TO THE SOUTHEAST OF PARADISE.
ALSO DURING THAT TIME PERIOD YOU CAN LOOK AT A POST FRONTAL DRY SLOT
THAT MOVED OVER THAT AREA IN THE WATER VAPOR IMAGERY. THIS DRY SLOT
HELPED TO CREATE THE PERFECT ENVIRONMENT WITH DRYER AIR ALOFT AND A
BOUNDARY FOR WHICH THE TORNADOES TO BE SPAWNED.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
945 PM PDT WED MAY 25 2011
.DISCUSSION...
BUSY DAY TODAY THAT IS WINDING DOWN. A NUMBER OF TORNADO
SITINGS TODAY OVER GLEN AND BUTTE COUNTIES THAT STARTED SHORTLY
AFTER 5 PM. FOUR DISTINCT CELLS PRODUCED MULTIPLE TORNADOES TODAY.
THERE IS CURRENTLY A COUPLE OF PEOPLE IN THE AREA DOING A STORM
SURVEY...BUT FROM A PRELIMINARY LOOK BACK AT DOPPLER RADAR THERE
WERE FOUR DISTINCT AREAS WHERE TORNADOES WHERE INDICATED. ONE
DECENT CELL THAT PRODUCING HAIL AND HEAVY RAIN AND LIGHTING SPLIT
AFTER IT CROSSED THE I-5 NEAR ARTOIS. TWO DISTINCT CELLS PRODUCING
TORNADOES DEVELOPED WITH ONE CELL MOVING JUST NORTH OF ORD BEND AND
ONE TO THE SOUTHERN END OF ORD BEND.
A LITTLE AFTER 6 PM THE SOUTHERN CELL SPLIT PRODUCING ANOTHER
TORNADO. ALSO TO THE EAST OF CHICO ONE FORMED...SO AT THIS TIME
THERE WAS FOUR CELLS ONE TO THE EAST OF CHICO...ONE SOUTH OF
CHICO...ONE NEAR DAYTON AND ONE NEAR DURHAM. THE SOUTHERN TWO CELLS
STAYED TOGETHER THE LONGEST BEFORE DECREASING IN INTENSITY BY 7:30
PM TO THE SOUTHEAST OF PARADISE.
ALSO DURING THAT TIME PERIOD YOU CAN LOOK AT A POST FRONTAL DRY SLOT
THAT MOVED OVER THAT AREA IN THE WATER VAPOR IMAGERY. THIS DRY SLOT
HELPED TO CREATE THE PERFECT ENVIRONMENT WITH DRYER AIR ALOFT AND A
BOUNDARY FOR WHICH THE TORNADOES TO BE SPAWNED.
R R Smith
EF0
...FINAL STORM SURVEY FOR MAY 25TH 2011 NORTHERN CALIFORNIA TORNADO OUTBREAK... THE DAMAGE ASSESSMENTS CONDUCTED BY THE NWS SACRAMENTO OFFICE ON 5/25/11 AND 5/27/11 CONCLUDED THAT BETWEEN 5:00 PM AND 7:30 PM,
THREE TORNADOES MOVED THROUGH THE GLENN AND BUTTE COUNTY REGION. TWO OF THE TORNADOES HAVE BEEN RATED EF1 AND THE THIRD AS AN EF2. NO FATALITIES OR INJURIES HAVE BEEN ASSOCIATED WITH ANY OF THE THREE TORNADIC EVENTS. THE FIRST AND NORTHERNMOST TORNADO DEVELOPED EAST OF THE TOWN OF ARTOIS IN GLENN COUNTY AT APPROXIMATELY 5:08 PM AND MOVED EAST-NORTHEAST, PASSING SOUTH OF THE TOWN OF CHICO IN BUTTE COUNTY. IT CAUSED SIGNIFICANT DAMAGE TO AN ALMOND GROVE IN GLENN COUNTY AND LESS SIGNIFICANT DAMAGE TO FARM IMPLEMENTS, ROOFING MATERIALS, AND ANOTHER ALMOND GROVE ACROSS ITS PATH. THE RATING OF AN EF1 WAS BASED UPON THE UPROOTING OF HUNDREDS OF ALMOND TREES WITH A FEW INSTANCES OF BROKEN LARGE BRANCHES AND TRUNKS. THE ESTIMATED HIGHEST WIND SPEED (3 SECOND GUST) BASED UPON DAMAGE WITH THIS TORNADO IS 95 MPH. THIS IS IN THE MIDDLE OF THE EF1 SCALE, WHICH RANGES FROM 86 MPH TO 110 MPH.
THE SECOND TORNADO DEVELOPED JUST SOUTH OF THE FIRST TORNADO AND WITHIN A FEW MINUTES TIME. IT ALSO MOVED EAST-NORTHEAST AND PASSED JUST SOUTH OF THE TOWN OF DURHAM IN BUTTE COUNTY. IT CAUSED SIGNIFICANT DAMAGE TO ALMOND GROVES IN BUTTE COUNTY, AS WELL AS DESTROYED ONE OUT BUILDING, DAMAGED AN OPEN BARN, AND CAUSED ROOFING DAMAGE TO TWO OTHER STRUCTURES. THE RATING OF AN EF1 WAS BASED UPON THE UPROOTING OF THOUSANDS OF ALMOND TREES WITH MANY INSTANCES OF BROKEN LARGE BRANCHES AND TRUNKS AND THE PHYSICAL LIFTING AND CARRYING OF SEVERAL LARGE TREES BY FIVE TO TEN FEET. THE ESTIMATED HIGHEST WIND SPEED (3 SECOND GUST) BASED UPON DAMAGE WITH THIS TORNADO IS 105 MPH. THIS IS AT THE HIGHER END OF THE EF1 SCALE, WHICH RANGES FROM 86 MPH TO 110 MPH.
THE THIRD TORNADO DEVELOPED APPROXIMATELY TEN MILES NORTHWEST OF OROVILLE IN BUTTE COUNTY AT APPROXIMATELY 645 PM AND MOVED NORTHEAST. IT CAUSED SIGNIFICANT DAMAGE TO A RANCH PROPERTY NEAR THE INTERSECTION OF TABLE MOUNTAIN ROAD AND HWY 70 INCLUDING THE DESTRUCTION OF A LARGE, WELL BUILT GARAGE AND SIGNIFICANT DAMAGE TO AN OPEN BARN. THE RATING OF AN EF2 WAS BASED UPON THE DESTRUCTION OF THE GARAGE, THOUGH EVIDENCE WAS FOUND OF THE FOOTING BOARDS BEING BOLTED TO THE SLAB IN THE FRONT PORTION OF THE STRUCTURE. THE ESTIMATED HIGHEST WIND SPEED (3 SECOND GUST) BASED UPON DAMAGE WITH THIS TORNADO IS 120 MPH. THIS IS AT THE LOWER END OF THE EF2 SCALE, WHICH RANGES FROM 111 MPH TO 135 MPH.
THESE WERE THE FIFTH, SIXTH AND SEVENTH CONFIRMED TORNADOES IN THE PAST THREE MONTHS... EIGHT TOTAL IN THE PAST SIX MONTHS.
- MAY 25, 2011: ONE EF2 TORNADO NORTH OF OROVILLE IN BUTTE COUNTY
- MAY 25, 2011: TWO EF1 TORNADOES IN GLENN AND BUTTE COUNTIES
- APRIL 7, 2011: EF0 TORNADO AT ROCKVILLE IN SOLANO COUNTY
- MARCH 23, 2011: EF0 TORNADO AT WILLIAMS IN COLUSA COUNTY
- MARCH 21, 2011: EF0 TORNADO AT MAXWELL IN COLUSA COUNTY
- FEBRUARY 25, 2011: EF0 TORNADO AT MATHER IN SACRAMENTO COUNTY
- NOVEMBER 23, 2010: EF1 TORNADO NEAR LATROBE IN EL DORADO COUNTY $$
THREE TORNADOES MOVED THROUGH THE GLENN AND BUTTE COUNTY REGION. TWO OF THE TORNADOES HAVE BEEN RATED EF1 AND THE THIRD AS AN EF2. NO FATALITIES OR INJURIES HAVE BEEN ASSOCIATED WITH ANY OF THE THREE TORNADIC EVENTS. THE FIRST AND NORTHERNMOST TORNADO DEVELOPED EAST OF THE TOWN OF ARTOIS IN GLENN COUNTY AT APPROXIMATELY 5:08 PM AND MOVED EAST-NORTHEAST, PASSING SOUTH OF THE TOWN OF CHICO IN BUTTE COUNTY. IT CAUSED SIGNIFICANT DAMAGE TO AN ALMOND GROVE IN GLENN COUNTY AND LESS SIGNIFICANT DAMAGE TO FARM IMPLEMENTS, ROOFING MATERIALS, AND ANOTHER ALMOND GROVE ACROSS ITS PATH. THE RATING OF AN EF1 WAS BASED UPON THE UPROOTING OF HUNDREDS OF ALMOND TREES WITH A FEW INSTANCES OF BROKEN LARGE BRANCHES AND TRUNKS. THE ESTIMATED HIGHEST WIND SPEED (3 SECOND GUST) BASED UPON DAMAGE WITH THIS TORNADO IS 95 MPH. THIS IS IN THE MIDDLE OF THE EF1 SCALE, WHICH RANGES FROM 86 MPH TO 110 MPH.
THE SECOND TORNADO DEVELOPED JUST SOUTH OF THE FIRST TORNADO AND WITHIN A FEW MINUTES TIME. IT ALSO MOVED EAST-NORTHEAST AND PASSED JUST SOUTH OF THE TOWN OF DURHAM IN BUTTE COUNTY. IT CAUSED SIGNIFICANT DAMAGE TO ALMOND GROVES IN BUTTE COUNTY, AS WELL AS DESTROYED ONE OUT BUILDING, DAMAGED AN OPEN BARN, AND CAUSED ROOFING DAMAGE TO TWO OTHER STRUCTURES. THE RATING OF AN EF1 WAS BASED UPON THE UPROOTING OF THOUSANDS OF ALMOND TREES WITH MANY INSTANCES OF BROKEN LARGE BRANCHES AND TRUNKS AND THE PHYSICAL LIFTING AND CARRYING OF SEVERAL LARGE TREES BY FIVE TO TEN FEET. THE ESTIMATED HIGHEST WIND SPEED (3 SECOND GUST) BASED UPON DAMAGE WITH THIS TORNADO IS 105 MPH. THIS IS AT THE HIGHER END OF THE EF1 SCALE, WHICH RANGES FROM 86 MPH TO 110 MPH.
THE THIRD TORNADO DEVELOPED APPROXIMATELY TEN MILES NORTHWEST OF OROVILLE IN BUTTE COUNTY AT APPROXIMATELY 645 PM AND MOVED NORTHEAST. IT CAUSED SIGNIFICANT DAMAGE TO A RANCH PROPERTY NEAR THE INTERSECTION OF TABLE MOUNTAIN ROAD AND HWY 70 INCLUDING THE DESTRUCTION OF A LARGE, WELL BUILT GARAGE AND SIGNIFICANT DAMAGE TO AN OPEN BARN. THE RATING OF AN EF2 WAS BASED UPON THE DESTRUCTION OF THE GARAGE, THOUGH EVIDENCE WAS FOUND OF THE FOOTING BOARDS BEING BOLTED TO THE SLAB IN THE FRONT PORTION OF THE STRUCTURE. THE ESTIMATED HIGHEST WIND SPEED (3 SECOND GUST) BASED UPON DAMAGE WITH THIS TORNADO IS 120 MPH. THIS IS AT THE LOWER END OF THE EF2 SCALE, WHICH RANGES FROM 111 MPH TO 135 MPH.
THESE WERE THE FIFTH, SIXTH AND SEVENTH CONFIRMED TORNADOES IN THE PAST THREE MONTHS... EIGHT TOTAL IN THE PAST SIX MONTHS.
- MAY 25, 2011: ONE EF2 TORNADO NORTH OF OROVILLE IN BUTTE COUNTY
- MAY 25, 2011: TWO EF1 TORNADOES IN GLENN AND BUTTE COUNTIES
- APRIL 7, 2011: EF0 TORNADO AT ROCKVILLE IN SOLANO COUNTY
- MARCH 23, 2011: EF0 TORNADO AT WILLIAMS IN COLUSA COUNTY
- MARCH 21, 2011: EF0 TORNADO AT MAXWELL IN COLUSA COUNTY
- FEBRUARY 25, 2011: EF0 TORNADO AT MATHER IN SACRAMENTO COUNTY
- NOVEMBER 23, 2010: EF1 TORNADO NEAR LATROBE IN EL DORADO COUNTY $$
