General Elsewhere Weather

Tulsa Briefing


www.srh.noaa.gov/tsa/?n=camtasiaBriefing

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
1048 AM CDT MON MAY 20 2013

DAMAGE SURVEY TEAMS IN THE SHAWNEE OKLAHOMA AREA HAVE FOUND PRELIMINARY
INDICATIONS OF EF-4 DAMAGE. FURTHER UPDATES AND MORE DETAILED INFORMATION
OF THIS AND OTHER TORNADO DAMAGE AREAS WILL BE RELEASED LATER TODAY AND
TUESDAY.

From 28 Storms : AP reporting at least 2 fatalities in Shawnee, Oklahoma, from yesterday's tornado #OKwx

Latest SPC outlook has not changed. The "general risk" has been pushed into the north shore though.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
1150 AM CDT MONDAY MAY 20 2013

SEVERE THUNDERSTORMS ARE EXPECTED ACROSS PARTS OF THE AREA. THE
NATIONAL WEATHER SERVICE IN NORMAN URGES YOU TO TAKE THIS TIME TO
THINK ABOUT WHAT YOU WILL DO TO STAY SAFE IF STORMS APPROACH.

MAKE SURE YOU HAVE MORE THAN ONE SOURCE OF LOCAL WEATHER WARNINGS
AND INFORMATION. IF YOU HAVE A WEATHER RADIO, BE SURE IT IS WORKING
PROPERLY. THINK ABOUT HOW YOU'LL RECEIVE A WARNING IF YOU LOSE CELL
PHONE OR INTERNET SERVICE.

CHECK THE WEATHER OFTEN THROUGHOUT THE DAY. IF YOU WILL BE TRAVELING
OR HAVE OUTDOOR ACTIVITIES PLANNED, BE SURE YOU CAN GET THE LATEST
WEATHER INFORMATION AND KEEP UP WITH DEVELOPING SEVERE WEATHER.

IF STORMS THREATEN YOU, REMEMBER THESE BASIC SAFETY GUIDELINES:

SEVERE THUNDERSTORMS PRODUCE LARGE HAIL AND DAMAGING WINDS. IF YOU
HEAR A SEVERE THUNDERSTORM WARNING FOR YOUR LOCATION, SEEK SHELTER
IN A STURDY BUILDING, AND STAY AWAY FROM DOORS AND WINDOWS. IF
YOU'RE DRIVING, FIND SUBSTANTIAL SHELTER TO AVOID BEING CAUGHT IN
LARGE HAIL AND STRONG WINDS. AND REMEMBER THAT EVERY THUNDERSTORM
PRODUCES DANGEROUS LIGHTNING, AND THAT NO PLACE OUTSIDE IS SAFE.

IF YOU HEAR A TORNADO WARNING FOR YOUR LOCATION, OR FEEL THREATENED
BY A TORNADO, YOU NEED TO ACT QUICKLY TO PROTECT YOURSELF. AN
UNDERGROUND SHELTER OR SAFE ROOM IS THE SAFEST PLACE. IF NO
UNDERGROUND SHELTER IS AVAILABLE, TAKE COVER IN A STURDY BUILDING.
GO TO THE LOWEST FLOOR AND STAY AWAY FROM DOORS, WINDOWS AND OUTSIDE
WALLS. YOUR GOAL IS TO PUT AS MANY WALLS BETWEEN YOU AND THE TORNADO
AS YOU CAN. YOU SHOULD PROTECT YOURSELF FROM FLYING AND FALLING
DEBRIS WITH PILLOWS OR BLANKETS. MOBILE HOMES AND VEHICLES ARE NOT
SAFE IN A TORNADO, SO BE SURE YOU HAVE PLENTY OF TIME TO GET TO A
STURDY SHELTER.

MONITOR THE LATEST INFORMATION FROM THE NATIONAL WEATHER SERVICE IN
NORMAN BY LISTENING TO WEATHER RADIO OR BY VISITING OUR WEBSITE AT
WEATHER.GOV/NORMAN.

$$

Chasers are actually starting to reposition further south, indications are that cells will become mature fairly quickly.

Mesoscale Discussion 726



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MESOSCALE DISCUSSION 0726
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT MON MAY 20 2013

AREAS AFFECTED...MUCH OF OK INTO NWRN TX AND SERN KS

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 201726Z - 201930Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SEVERE STORMS ARE LIKELY TO FORM THIS AFTERNOON WITH A FEW
SIGNIFICANT TORNADOES...EXTREMELY LARGE HAIL...AND DAMAGING WINDS
ALL POSSIBLE. TWO WATCHES WILL BE NEEDED SOON FROM KS INTO N TX.

DISCUSSION...SURFACE MAP SHOWS A QUASI-STATIONARY BOUNDARY FROM SERN
KS INTO NRN OK AND BENDING SWWD W OF THE I-44 CORRIDOR. FARTHER
SW...A WEAK AREA OF LOW PRESSURE WAS NOTED OVER NWRN TX...ON THE
NOSE OF A LOW LEVEL LAPSE RATE PLUME WITH DRYLINE EXTENDING SW
ACROSS W TX.

VISIBLE IMAGERY SHOWS DEEPENING CU ALONG THE BOUNDARY FROM NRN OK
INTO SERN KS WHERE A DEEP MOIST LAYER EXISTS. GIVEN A GRADUAL
INCREASE IN THETA-E AND BREAKS IN THE CLOUDS...THIS AREA COULD BE
WHERE INITIAL DEVELOPMENT OCCURS. LONG HODOGRAPHS AND STEEP MIDLEVEL
LAPSE RATES WILL FAVOR VERY LARGE HAIL...AND LOW LEVEL VEERING WIND
PROFILES WILL BE SUFFICIENT FOR TORNADOES GIVEN AFOREMENTIONED
THERMODYNAMIC FACTORS.

TO THE S...AN EXTREMELY VOLATILE AIR MASS EXISTS WITH AN INCREASING
CU FIELD FROM NWRN TX INTO SWRN OK WHERE STRONG HEATING PERSISTS.
WIND FIELDS ALOFT ARE MORE THAN FAVORABLE FOR SUPERCELLS...WITH VERY
LARGE HAIL LIKELY. ALTHOUGH SHEAR IN THE LOWEST 1-2 KM IS NOT
PARTICULARLY STRONG...VERY LARGE VERTICAL ACCELERATIONS...AS WELL AS
HODOGRAPH AUGMENTATION NEAR THE SFC FRONT WILL AID IN TORNADO
POTENTIAL. HP SUPERCELLS ARE EXPECTED WITH STRONG MESOCYCLONES AND
POSSIBLE RAIN-WRAPPED TORNADOES.

ACTIVITY MAY EVENTUALLY MERGE INTO ONE OR MORE BOWS...AND RAPIDLY
EXPAND NEWD ACROSS ERN OK LATER THIS EVENING PER MULTIPLE CONVECTION
ALLOWING MODELS.

..JEWELL/KERR.. 05/20/2013


ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT...FWD...OUN...
SJT...