Public Information Statement
Issued by NWS Tulsa, OK

000
NOUS44 KTSA 190205
PNSTSA
ARZ001-002-010-011-019-020-029-OKZ049-053>076-191415-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
905 PM CDT THU APR 18 2013

...NWS DAMAGE SURVEY FOR 04/17-18/2013 TORNADO EVENT...

.OVERVIEW...A LINE OF THUNDERSTORMS DEVELOPED AHEAD OF AN
APPROACHING COLD FRONT MOVING INTO EASTERN OKLAHOMA DURING THE
LATE EVENING OF APRIL 17TH. THIS LINE OF THUNDERSTORMS EVOLVED
INTO A BOW ECHO AND MOVED SWIFTLY ACROSS NORTHEASTERN OKLAHOMA AND
INTO NORTHWESTERN ARKANSAS...PRODUCING WIND DAMAGE...LARGE HAIL...
AND SEVERAL TORNADOES. THE TORNADOES WERE ASSOCIATED WITH RATHER
BRIEF CIRCULATIONS THAT APPARENTLY EVOLVED FROM THE INTERACTION
OF THUNDERSTORMS NEAR THE APEX OF THE BOW WITH THE QUASISTATIONARY
FRONTAL BOUNDARY.

.SPAVINAW OKLAHOMA TORNADO...

RATING:                 EF-1
ESTIMATED PEAK WIND:    100-110 MPH
PATH LENGTH /STATUTE/:  3.5 MILES
PATH WIDTH /MAXIMUM/:   350 YARDS
FATALITIES:             0
INJURIES:               0

START DATE:             APRIL 18 2013
START TIME:             107 AM CDT
START LOCATION:         2.1 SW SPAVINAW / MAYES COUNTY / OK
START LAT/LON:          36.3752 / -95.0788

END DATE:               APRIL 18 2013
END TIME:               113 AM CDT
END LOCATION:           1.4 NE SPAVINAW / MAYES COUNTY / OK
END_LAT/LON:            36.4011 / -95.0248

SURVEY SUMMARY: THIS TORNADO DEVELOPED IN THE CYCLONIC COMMA HEAD
OF THE BOW ECHO...WELL BEHIND THE INITIAL STORM SURGE AND GUST
FRONT. IT DEVELOPED SOUTH OF THE EAST 440 ROAD SOUTHWEST OF
SPAVINAW...SNAPPING AND UPROOTING NUMEROUS TREES AS IT APPROACHED
THE TOWN. NUMEROUS HOMES WERE DAMAGED...INCLUDING SEVERAL MOBILE
HOMES THAT WERE DESTROYED...THE ROOF OF THE SCHOOL WAS SEVERELY
DAMAGED...TREES AND POWER POLES WERE BLOWN DOWN...AND SEVERAL
BUSINESSES WERE DAMAGED AS THE TORNADO MOVED THROUGH TOWN. IT
DISSIPATED SOUTH OF HIGHWAY 20 NORTHEAST OF TOWN.

.BUTLER OKLAHOMA TORNADO...

RATING:                 EF-2
ESTIMATED PEAK WIND:    115-125 MPH
PATH LENGTH /STATUTE/:  8 MILES
PATH WIDTH /MAXIMUM/:   800 YARDS
FATALITIES:             0
INJURIES:               0

START DATE:             APRIL 18 2013
START TIME:             130 AM CDT
START LOCATION:         4 E ZENA / DELAWARE COUNTY / OK
START LAT/LON:          36.4918 / -94.7809

END DATE:               APRIL 18 2013
END TIME:               140 AM CDT
END LOCATION:           7 SE GROVE / DELAWARE COUNTY / OK
END_LAT/LON:            36.5513 / -94.6567

SURVEY SUMMARY: THIS TORNADO DEVELOPED ALONG THE LEADING EDGE OF
THE BOW ECHO. IT FORMED JUST EAST OF HIGHWAY 59...SOUTH OF
HIGHWAY 127. THE MOST INTENSE STAGE OF THIS TORNADO`S LIFECYCLE
WAS EARLY ON AS IT PRODUCED AN 800 YARD WIDE CORRIDOR OF
IMPRESSIVE TREE DAMAGE AS IT CROSSED THE 628 ROAD AND SEVERELY
DAMAGED A PERMANENT HOME. NUMEROUS TREES WERE SNAPPED AND
UPROOTED...POWER POLES WERE BLOWN DOWN...HOMES WERE DAMAGED...AND
BARNS WERE DESTROYED AS THE TORNADO MOVED NORTHEAST. IT DISSIPATED
ABOUT 2 MILES WEST OF THE MISSOURI STATE LINE...NORTH OF THE EAST
324 ROAD.

EF SCALE: THE ENHANCED FUJITA SCALE CLASSIFIES TORNADOES INTO THE
FOLLOWING CATEGORIES.

EF0...WEAK......65 TO 85 MPH
EF1...WEAK......86 TO 110 MPH
EF2...STRONG....111 TO 135 MPH
EF3...STRONG....136 TO 165 MPH
EF4...VIOLENT...166 TO 200 MPH
EF5...VIOLENT...>200 MPH

NOTE:
THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO CHANGE
PENDING FINAL REVIEW OF THE EVENTS AND PUBLICATION IN NWS STORM
DATA.

$$

EJC/MAT