SPC MD 1179

MD 1179 CONCERNING TORNADO WATCH 344…346…347… FOR MUCH OF NEB…NE CO…NW/N-CNTRL KS


MESOSCALE DISCUSSION 1179
NWS STORM PREDICTION CENTER NORMAN OK
0747 PM CDT SAT JUN 22 2013

AREAS AFFECTED...MUCH OF NEB...NE CO...NW/N-CNTRL KS

CONCERNING...TORNADO WATCH 344...346...347...

VALID 230047Z - 230215Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH
344...346...347...CONTINUES.

SUMMARY...SVR THREAT CONTINUES ACROSS TORNADO WATCHES
344...346...AND 347. AN INCREASING LLJ WILL PROMOTE A CONTINUED
TORNADO THREAT. SOME POTENTIAL EXIST FOR UPSCALE GROWTH INTO A
BOWING MCS LATER TONIGHT.

DISCUSSION...SURFACE ANALYSIS PLACES A COMPOSITE FRONTAL BOUNDARY
FROM FAR SW NEB/NW KS NEWD ACROSS CNTRL NEB INTO W-CNTRL IA AND INTO
FAR SW WI. THIS BOUNDARY IS EFFECTIVELY ACTING AS A WARM FRONT
ACROSS NEB WITH TEMPERATURES SOUTH OF THE BOUNDARY IN THE UPPER 80S
TO LOW 90S AND SLY WINDS AROUND 10-20 KT WHILE TEMPERATURES NORTH OF
THE BOUNDARY ARE THE UPPER 70S TO LOW 80S AND WINDS WERE ELY.
THUNDERSTORM ACTIVITY HAS GENERALLY REMAINED ISOLATED WITH THE
EXCEPTION OF A BOWING LINE SEGMENT ACROSS THE NEB PANHANDLE.

LLJ IS EXPECTED TO INCREASE ACROSS THE PLAINS DURING THE NEXT
SEVERAL HOURS. THIS INCREASE WILL ENLARGE HODOGRAPHS...PROMOTING A
CONTINUED TORNADO THREAT...PARTICULARLY IN THE VICINITY OF THE
BOUNDARY ACROSS NEB. ADDITIONALLY...THE INCREASED LLJ WILL ENCOURAGE
WAA WITH RESULTANT ELEVATED TSTM DEVELOPMENT EXPECTED N OF THE
BOUNDARY ACROSS N-CNTRL NEB.

FARTHER W...LINE OF TSTMS ACROSS THE NEB PANHANDLE IS GENERALLY
MOVING SEWD WHILE THE CLUSTER OVER NE CO MOVES ENEWD. INTERACTION
BETWEEN THESE TWO TSTM AREAS IN CONJUNCTION WITH THE WAA ACTIVITY
AND THE FRONTAL ZONE ACROSS NEB IS EXPECTED TO PROMOTE UPSCALE
GROWTH INTO BOWING MCS. MOST LIKELY TRACK APPEARS TO BE ACROSS WW
347 IN CNTRL NEB. 00Z LBF SOUNDING SAMPLED A VERY UNSTABLE AND
SUFFICIENTLY SHEARED ENVIRONMENT CAPABLE OF SUPPORTING ALL SVR
WEATHER THREATS.

..MOSIER.. 06/23/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OAX...GID...LBF...DDC...GLD...BOU...CYS...

LAT...LON   41600400 42420327 42810150 42829939 41639736 38859927
            38820346 41600400

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md1179.html