November 23, 2001

Arkansas Nighttime Supercells & Hunt, AR Tornado

Chase Account by: Scott Blair

Chase Team: Scott Blair, Jason Politte.
Jason Politte and I originally targeted a line from Sallisaw, OK to Clarksville, AR. We departed Central Arkansas around mid morning. With the dryline slowing, we gradually shifted west into Oklahoma. We ran into Eric Nguyen near Henryetta as we waited during the daylight hours for any signs of convection. There appeared to be several small boundaries across Eastern Oklahoma that we observed.

*** Preparing chase cars during mid morning ***

Finally, around 7pm convection exploded across NW Arkansas. Jason and I quickly moved east on I-40 as the cells were becoming supercellular. We entered the Arkansas border at 8pm. This was the same time frame that a monster supercell was crossing I-40 near Altus, AR. Unfortunately, this storm produced a strong F2 tornado that killed a woman in a mobile home. As this storm continued on its northeast track, more supercells developed in the same general area.

*** Jason Politte talking with nowcasters ***

We stopped in Ozark, AR to discuss the newly developed supercell just to the south. We checked with Dave Lewison and Phillip Flory (both did a fantastic job with nowcast updates) about the situation. NWS TUL had a severe warning out and warned of a "dangerous severe t-storm with some signs of rotation." Dave and Phillip observed a decent couplet, so we decided to intercept on I-40 as the cell would eventually cross the area.

*** Very close cg bolt ***

We carefully drove east and decided to stop just west of the Franklin/Johnson County border around 9pm just SW of Hunt, AR. Winds were generally out of the northwest around 10-15mph with light to moderate rain falling. CG lightning activity increased. This created quite a show, especially the bolt that struck just in front of the chase car.



*** Inflow to a possible tornado. Note the rapid change in conditions. ***

Within 5-10 minutes, the wind consistently increased from the NW around 20-25mph. Precip greatly increased and quarter sized hail began to fall. At 9:10pm, the situation became quite intense. The winds abruptly shifted from the west with a sustained speed of 50-60mph. Wrapping rain curtains became visible crossing the freeway. What appeared as fine mist, perhaps condensation, was thrown into the mix. This was certainly inflow winds. It is likely this was inflow into a weak tornado that crossed the road just to the east of our location. If not, it was certainly associated with the mesocyclone. Within 30 seconds of this event, all precip ended and winds shifted to the SW.


*** Departing meso near Hunt, AR and semi blocking I-40 ***

At 9:12pm, the NWS LIT issued a tornado warning for Johnson County which placed a tornado over Hunt, AR. This was in line with the exact path of the event experienced earlier. The intense winds from the event had resulted in a jack-knifed semi just down the road on I-40 West. The meso was more visible as it tracked off to the NE. It looked decent with a bowl-shape lowering and inflow tail.


We intercepted two more tornado-warned storms on the border of Johnson and Pope County near London, AR. While the convection was nice, nothing very suggestive materialized. The chase day ended around midnight near LIT as the squall line overtook the remaining isolated cells.

*** New tornado warned cell near Russellville, AR ***

Trees, hills, limited road network, and darkness provided quite a challenge. I was very pleased with the results of the chase since it was a much needed cure for SDS. I'm still not exactly sure what event we experienced near Hunt.


*** F2 Tornado track along the Franklin/Johnson Co. border ***

We conducted a damage survey today but the findings were inconclusive to which tornado track was ours. Problems we encountered:
1)Two confirmed tornadoes tracked within 1/10 of a mile from the 9:10pm event. Damage is pretty widespread in that area. Individual paths are rather difficult to find.
2)Associated RFD damage with previous tornadoes.
3)Large severe squall line moved through later causing further damage. A much needed chase day!


WFUS54 KLZK 240313TORLITARC071-240350-
BULLETIN - EAS ACTIVATION REQUESTED - TORNADO WARNING
NATIONAL WEATHER SERVICE LITTLE ROCK AR
912 PM CST FRI NOV 23 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A * TORNADO WARNING * FOR...
JOHNSON COUNTY IN WESTERN ARKANSAS * UNTIL 950 PM CST *

* AT 911 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A TORNADO OVER HUNT...OR ABOUT 8 MILES EAST OF OZARK...MOVING NORTHEAST AT 20 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR... HARMONY AROUND 925 PM CST YALE AROUND 930 PM CST CATALPA AND OARK AROUND 940 PM CST OZONE AROUND 945 PM CST

IF YOU ARE IN THE PATH OF THIS TORNADO...HEAD INDOORS NOW!!! GO TO AN INTERIOR ROOM AWAY FROM WINDOWS ON THE LOWEST FLOOR. PUT AS MANY WALLS BETWEEN YOURSELF AND THE OUTDOORS AS YOU CAN. ABANDON MOBILES HOMES NOW. MOVE TO A STRONG BUILDING OR UNDERGROUND SHELTER. IF THERE ARE NO BUILDINGS NEARBY...LIE IN A DITCH TO AVOID FLYING DEBRIS. BUT BEWARE OF RISING WATER.REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE. 54


SPC Mesoscale Discussions

#2250... SPC MESOSCALE DISCUSSION 2250 FOR ...ERN OK/SWRN MO/WRN AR/NERN TX/NWRN LA... CONCERNING...SEVERE THUNDERSTORM POTENTIAL... VALID 232059Z - 240000Z WE ARE MONITORING AREA FOR POSSIBLE TORNADO WATCH BY 00Z. MODELS HAVE BEEN INDICATING VERY STRONG MID/UPPER LEVEL WINDS MOVING INTO NWRN TX THIS AFTERNOON AND EXTENDING ENEWD TOWARD SERN OK/NERN TX BY THIS EVENING. PROFILER DATA HAS SHOWN 80-90 KT JET MAX ACROSS AZ INTO SRN NM NOW MOVING OVER W CENTRAL TX. THE WAIT HAS BEEN FOR A SECONDARY VORTICITY MAX TO MOVE THROUGH THE BOTTOM OF THE TROUGH OVER THE TX PANHANDLE/NWRN TX WHICH IS NOW HAPPENING ACCORDING TO THE LATEST IR SATELLITE IMAGERY.
AIR MASS ACROSS ERN TX AND LA HAS BECOME MODERATELY UNSTABLE WITH SBCAPE BETWEEN 1500 AND 3000 J/KG. LOW LEVEL WARM ADVECTION HAS BEEN MARGINAL THROUGH MUCH OF THE DAY...BUT IS EXPECTED TO ACCENTUATE ACROSS LA INTO AR IN THE NEXT FEW HOURS AS SECONDARY VORTICITY MAX BACKS THE LOW LEVEL FLOW WHEN IT BOTTOMS OUT IN THE MID/UPPER LEVEL TROUGH. SURFACE DEW POINTS ARE IN THE MID/UPPER 60S ACROSS SRN AR INTO LA AND SURFACE PRESSURE FALLS ARE CENTERED NOW OVER S CENTRAL TX WHICH SHOULD MOVE ACROSS CONCERNED AREA NEXT SEVERAL HOURS AS LOW LEVEL WARM ADVECTION INCREASES.
STRONG/SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS ERN OK/NERN TX WITHIN THE NEXT THREE HOURS AS DRYLINE MOVES EWD INTO AREA WHERE VERTICAL SHEAR PROFILES HAVE BEEN FAVORABLE AND IS EXPECTED TO INCREASE AS LOW LEVEL FLOW BACKS IN RESPONSE TO APPROACHING TROUGH. THUS...ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SUPERCELL STORMS DURING THE NEXT SEVERAL HOURS. ..MCCARTHY.. 11/23/01

#2251... SPC MESOSCALE DISCUSSION 2251 FOR ERN OK...NERN TX AND WRN AR CONCERNING...SEVERE THUNDERSTORM POTENTIAL... VALID 232316Z - 240000Z A TORNADO WATCH WILL LIKELY BE ISSUED FOR THE AREA BY 0000 UTC. LEADING EDGE OF THE ENHANCED LARGE SCALE UVV WITHIN LEFT EXIT REGION OF A STRONG MIDLEVEL JETLET IS CURRENTLY SPREADING EWD ACROSS CNTRL OK ATTM. SURFACE CONVERGENCE WILL LIKELY STRENGTHEN RAPIDLY ALONG A COLD FRONT/DRY LINE AS IT PUNCHES EWD FROM CNTRL INTO ERN OK BETWEEN 00-03 UTC. LOW LEVEL WARM ADVECTION HAS DESTABILIZED THE AIR MASS ACROSS ERN OK/WRN AR AND EXTREME NERN TX WITH SBCAPES RANGING FROM 1500-2000 J/KG. GIVEN INCREASED MASS CONVERGENCE WITHIN THE UNSTABLE ENVIRONMENT...TSTMS SHOULD RAPIDLY FORM WITHIN THE NEXT HOUR OR TWO.
MESOANALYSIS DEPICTS A SUBTLE WARM FRONT FROM CNTRL OK EWD INTO SWRN AR. THE LOW LEVEL FLOW REMAINS BACKED ALONG/NORTH OF THIS FRONT WITH MODIFIED DEQUEEN PROFILER SUGGESTING SUFFICIENT LOW LEVEL HELICITY FOR POSSIBLE TORNADOES. OTHERWISE...DEEP LAYER SHEAR IN EXCESS OF 45 KTS WILL PROMOTE ROTATING UPDRAFTS WITH VERY LARGE HAIL AND DAMAGING TSTM WIND GUSTS POSSIBLE. ACTIVITY WILL LIKELY BECOME LINEAR RAPIDLY THIS EVENING WITH EMBEDDED BOW ECHOES AND EMBEDDED SUPERCELLS POSSIBLE ACROSS AR. ..RACY.. 11/23/01

#2252... SPC MESOSCALE DISCUSSION 2252 FOR ERN OK...WRN AR AND EXTREME NERN TX CONCERNING...TORNADO WATCH 811... VALID 240059Z - 240300Z ISOLD TSTMS...EXHIBITING SIGNS OF ROTATION...CONTINUE TO DEVELOP RAPIDLY INVOF FSM. THESE STORMS ARE ALONG/NORTH OF A WEAK WARM FRONT SITUATED NW-SE FROM NEAR TUL INTO SCNTRL AR. GIVEN MAGNITUDE OF LOW LEVEL STORM RELATIVE HELICITY SHOWN ON THE DQU PROFILER... THESE STORMS WILL HAVE THE POTENTIAL FOR TORNADOES ALONG WITH LARGE HAIL AND DAMAGING WINDS.
SQUALL LINE IS QUICKLY BECOMING ORGANIZED FROM NEAR ADA SWD TO JUST NORTH OF THE DFW METROPLEX WITH 3 MB+ PRESSURE RISES OCCURING ACROSS NCNTRL TX. UPSTREAM PROFILERS/VWP SHOW A FAIRLY DEEP AND UNIDIRECTIONAL WLY FLOW REGIME WITH 40-50 KTS IN THE LOWEST 2 KM. GIVEN BOWING NATURE OF THE LINE...DAMAGING WIND POTENTIAL...WITH THE THREAT OF A FEW SIGNIFICANT WIND REPORTS...IS INCREASING RAPIDLY ACROSS SERN/ECNTRL OK INTO WRN AR/EXTREME NERN TX. EMBEDDED SUPERCELLS ARE ALSO POSSIBLE WITH LARGE HAIL AND ISOLD TORNADOES. ..RACY.. 11/24/01

#2254... SPC MESOSCALE DISCUSSION 2254 FOR ERN OK...WRN AR AND EXTREME NERN TX CONCERNING...TORNADO WATCH 811... VALID 240209Z - 240400Z A COUPLE TORNADIC SUPERCELLS CONTINUE TO MOVE NEWD ACROSS NWRN AR...WITH THE STRONGEST CELLS ABOUT 15 NE AND 45 ENE OF FSM. THE CELL OVER FRANKLIN COUNTY AR HAS HAD HISTORY OF TORNADOES SINCE 0130 UTC.
MESOANALYIS DEPICTS A WARM FRONT SITUATED ACROSS ECNTRL OK INTO CNTRL AR ATTM. AIR MASS SOUTH OF THE FRONT REMAINS UNSTABLE WITH MUCAPES TO 2000 J/KG. INDIVIDUAL CELLS CONTINUE TO FORM WITHIN THIS ENVIRONMENT AND BECOME SEVERE GIVEN DEEP LAYER SHEAR VALUES IN EXCESS OF 45 KTS. POTENTIAL STILL EXISTS FOR TORNADOES WITH THESE TSTMS AS THEY MOVE NEWD AND ENCOUNTER STRONGER BACKED LOW LEVEL FLOW/HELICITY...ESPECIALLY FROM LIT-RUE-FUV. KLZK VWP SUGGESTS 0-2 KM STORM RELATIVE HELICITY IN EXCESS OF 510 M2S2. DAMAGING WINDS AND LARGE HAIL CAN ALSO BE EXPECTED.
FARTHER WEST...LINEAR BAND OF TSTMS WITH EMBEDDED BOW ECHOES CONTINUES TO ORGANIZE ACROSS ERN OK. THE LINE WAS MOVING ENEWD AT 40-45 KTS AND WILL BE ALONG THE AR/OK LINE BY 0300 UTC. DAMAGING WINDS...WITH THE POTENTIAL FOR SIGNIFICANT WIND DAMAGE...WILL BE THE MAIN THREAT FROM THESE STORMS...ALTHOUGH HAIL AND ISOLD TORNADOES WILL BE POSSIBLE ASSOCIATED WITH EMBEDDED SUPERCELLS. ..RACY.. 11/24/01