Severe Thunderstorm Warning 57, NWS Topeka, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
753 PM CDT MON MAY 27 2013

.MESOSCALE DISCUSSION...
ISSUED AT 739 PM CDT MON MAY 27 2013

A LINE OF THUNDERSTORMS WITH 4 DISCRETE CELLS ALONG THE LINE FROM
RUSSELL KANSAS TO THE NEBRASKA BORDER. THESE INDIVIDUAL UPDRAFTS
HAVE STRONG MID LEVEL ROTATION AND PERIODS OF STRONG LOW LEVEL
MESOCYCLONES. THE SHEAR PROFILE WILL INCREASE IN INTENSITY AND
DIRECTIONAL TURNING THROUGH 9 PM AND BE MAINTAINED THROUGH THE REST
OF THE EVENING WITH LOW LEVEL EFFECTIVE HELICITY IN EXCESS OF 300 TO
500 M2/S2. MEANWHILE...AN UPPER LEVEL JET STREAK WILL INCREASE THE
MID TO JET LEVEL WINDS FROM 9 PM THROUGH THE REST OF THE EVENING.
THE SHEAR PROFILE IS FAVORABLE FOR THE CONTINUATION OF SUPERCELL
STRUCTURES...EVEN WITHIN POTENTIAL LINEAR UPSCALE DEVELOPMENT. ANY
DISCRETE STORMS FROM THIS TIME ON WILL SEE INCREASING TORNADO
POTENTIAL AS LONG AS THEY CAN REMAIN ROOTED ON THE SURFACE. IT WOULD
APPEAR THAT THE GREATEST LIKELIHOOD FOR TORNADOES WOULD FALL BETWEEN
8 PM AND 11 PM IN DISCRETE STORMS AND EVEN SOME OF THE EMBEDDED
SUPERCELL STRUCTURES WITHIN UPSCALE LINEAR DEVELOPMENT. IF
TEMPERATURES REMAIN WARM IN ADVANCE OF THE CONVECTION...THAT TORNADO
THREAT WILL CONTINUE DEEPER INTO THE NIGHT UNTIL THE CAP STRENGTHENS
SUFFICIENTLY TO MITIGATE TORNADO THREAT.

THERE IS A GENERAL EXPECTATION FOR THE COLD POOLS FROM THESE STORMS
TO EVENTUALLY CONGEAL INTO FORWARD PROPAGATING MCS WITH SIGNIFICANT
WIND POTENTIAL AND SOME CONTINUED HAIL POTENTIAL. THE TRACK WOULD
LIKELY BE INITIALLY EAST WITH AN EVENTUAL TURN TOWARD THE EAST
SOUTHEAST AS IT MOVES INTO EASTERN KANSAS. ANY STORMS ON THE
SOUTHERN END OF THE LINE WILL MAINTAIN SOME TORNADO
POTENTIAL...ALONG WITH ANY INFLECTION POINTS ALONG A WARM FRONT
SITUATED ACROSS NORTHERN KANSAS...AND WITHIN ANY STRONG EMBEDDED
SUPERCELL STRUCTURES/MID LEVEL ROTATION THAT CAN BE MAINTAINED
WITHIN THE MCS.

BARJENBRUCH

&&

.SHORT TERM...
ISSUED AT 243 PM CDT MON MAY 27 2013

REST OF MONDAY THROUGH TONIGHT...

SURFACE ANALYSIS AT 18Z SHOWS A STRONG SURFACE CYCLONE AROUND 998 TO
1000 MB LOCATED JUST WEST OF KHYS. THE SURFACE TROUGH IS GETTING A
BIT DEEPER AS THE DAY PROGRESSES AS EARLIER IT WAS ANALYZED BETWEEN
1000 TO 1002 MB. THE TIGHT SURFACE PRESSURE GRADIENT HAS ALLOWED FOR
SOUTHERLY WINDS TO PUSH NORTHWARD USHERING IN GOOD RICH GULF
MOISTURE INTO EASTERN KANSAS. VISIBLE IMAGERY SHOWS A VERY WELL
DEFINED OUTFLOW BOUNDARY FROM THIS MORNING'S MCS LIES ON A LINE FROM
KIMP ARCING SOUTHEASTWARD TOWARD KPPF. SKIES HAVE BEEN CLEAR ACROSS
THE AREA LEADING TO SIGNIFICANT DESTABILIZATION...CHARACTERIZED BY
ML CAPE VALUES OF AROUND 3000 TO 4000 J/KG. AS MORE MOISTURE STREAMS
INTO THE AREA AND HEATING CONTINUES WE COULD SEE BOUNDARY LAYER
CONDITIONS IN THE LOWER 80S WITH DEWPOINTS IN THE UPPER 60S TO LOWER
70S. THIS WOULD LIKELY LEAD TO ML CAPE VALUES HIGHER THAN THE
CURRENT 3000 J/KG. ALSO AT THE SURFACE A VERY PRONOUNCED DRY LINE IS
CURRENTLY ANALYZED NOSING INTO THE KGBD AREA. HOT/DRY SOUTHWEST
WINDS ARE CURRENTLY ENCOUNTERING THE MOIST E/SE WINDS IN THAT KGBD
AREA. THIS AREA WILL PROVIDE THE BEST LOW LEVEL CONVERGENCE FOR
ASCENT...ONCE WE CAN ERODE THE CAP AND GET SOME MID LEVEL ASCENT.
CURRENTLY THE VISIBLE SATELLITE NEAR THE DRYLINE/OUTFLOW
BOUNDARY/WARM FRONT TRIPLE POINT AREA SHOWS LITTLE IN THE WAY OF
CUMULUS FIELD DEVELOPMENT AS THE CAP HOLDS STRONG. FURTHER WEST ON
SATELLITE IT LOOKS AS THOUGH HIGH BASED DEEP CONVECTION IS
OCCURRING...PROBABLY IN RESPONSE TO AN APPROACHING SHORTWAVE TROUGH
COMING OFF THE HIGH PLAINS. ONCE THAT MID LEVEL ASCENT REACHES
CENTRAL KANSAS EXPECT RAPID DEVELOPMENT OF STRONG THUNDERSTORMS
CAPABLE OF PRODUCING LARGE HAIL...STRONG WINDS...AND POSSIBLY SOME
TORNADOES.

EXPECT CONVECTIVE INITIATION TO OCCUR BETWEEN 21 AND 22Z WITH
INITIAL DEVELOPMENT TAKING PLACE BETWEEN KGBD AND K9K7 (ELLSWORTH).
DEEP LAYER SHEAR VECTORS COME OUT OF THE WEST AT 40 TO 50 KTS
INDICATING THAT STORMS WILL BE ABLE TO GROW UPSCALE TO SUPERCELLS
VERY QUICKLY WHILE MOVING EASTWARD. GIVEN THE STRONG SHEAR/CAPE
RELATIONSHIP IT APPEARS LIKELY THAT LARGE HAIL UP TO THE SIZE OF
BASEBALLS WILL OCCUR WITH ANY STORM THAT CAN REMAIN DISCRETE. SINCE
STORMS WILL BE SURFACE BASED IT IS ALSO LIKELY THAT THE STRONGEST
STORMS WILL BE ABLE TO PRODUCE STRONG WINDS POTENTIALLY REACHING 70
TO 80 MPH.

THE TORNADO THREAT FOR PORTIONS OF CENTRAL AND NORTH CENTRAL KANSAS
REMAIN RATHER ELEVATED FOR TONIGHT. THE MOST STRIKING PART OF THIS
PARTICULAR EVENT...OTHER THAN THE EXTREME CAPE/AND DEEP LAYER SHEAR
IS THE STRONGLY CLOCKWISE CURVED HODOGRAPHS. THE OUTFLOW
BOUNDARY...IN COMBO WITH THE SURFACE SYNOPTIC WINDS HAVE CAUSED A
STRONG SOUTHEASTERLY COMPONENT TO THE SURFACE WINDS. IN THE 21Z TO
03Z TIME FRAME MODELS INDICATED A BACKING AND STRENGTHENING OF THE
LOW LEVEL JET TO AROUND 25 KTS BY 00Z AND UP TO 40-50 KTS BY 03Z.
THIS WILL CAUSE A LENGTHENING OF THE LOW LEVEL HODOGRAPH...YIELDING
0-1 SRH VALUES APPROACHING 150 J/KG BY 00Z AND OVER 300 J/KG BY 03Z.
SHOULD A SUPERCELL OR TWO BE ABLE TO STAY DISCREET IN GOOD MOISTURE
WITH LOW LCL'S THE EXTREME LOW LEVEL SHEAR WILL MAKE TORNADIC
ACTIVITY A STRONG POSSIBILITY...ESPECIALLY ACROSS C/NC KANSAS...WEST
OF MANHATTAN.

IT IS TOUGH TO SAY EXACTLY HOW LONG THE STORMS WILL BE ABLE TO
REMAIN DISCREET...AS SOME SHORT RANGE MODELS INDICATE A QUICK
TRANSITION INTO LINEAR MODE...PERHAPS AS EARLY AS 01Z. SHOULD STORMS
REMAIN DISCREET THE TORNADO THREAT WILL CONTINUE THROUGH THE
NIGHT...HOWEVER AS STORMS BECOME MORE CONGEALED AND LINEAR IN NATURE
THE TORNADO THREAT WILL DIMINISH SOMEWHAT...BUT AS THE LOW LEVEL
SHEAR INCREASES OVERNIGHT EVEN LINEAR CONVECTION WILL BE ABLE TO
PRODUCE TORNADIC SPIN UPS...ESPECIALLY IF IT ENCOUNTERS ANY
LINGERING BOUNDARIES FROM PREVIOUS CONVECTION...ESPECIALLY THE PRE
EXISTING OUT FLOW BOUNDARY. THE LINEAR MCS WILL ALSO HAVE A STRONG
WIND THREAT AS IT MOVES EASTWARD THROUGH THE EASTERN HALF OF THE
FORECAST AREA LATER TONIGHT. SOME MODEL GUIDANCE INDICATES THAT THE
LINEAR CONVECTION MAY EXIT THE AREA BY MIDNIGHT...OR PERHAPS A
COUPLE HOURS THEREAFTER.  EXPECT MOSTLY LIGHT LINGERING RAIN THROUGH
TUESDAY MORNING AFTER THE HEAVIEST RAIN FROM THE MCS MOVES EAST OF
THE AREA.

JL

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 243 PM CDT MON MAY 27 2013

SEVERE THUNDERSTORMS MAY RETURN TO THE AREA ON TUESDAY AFTERNOON BUT
MUCH REMAINS TO BE RESOLVED IN TERMS OF SMALL SCALE FEATURES AND
OUTFLOW FROM TONIGHTS CONVECTION. IT SEEMS AS THOUGH THE MORNING WILL
PROBABLY BE DRY WITH ANY MCS ACTIVITY HAVING PUSHED OUT OF THE AREA.
BY AFTERNOON MOST MODEL GUIDANCE SUGGESTS A SOUTHWEST TO NORTHEAST
ORIENTED CONVERGENCE ZONE NEARLY BISECTING THE FORECAST AREA. THIS
SHOULD BECOME A FOCUS FOR AFTERNOON CAP WEAKENING...LIKELY TO THE
POINT OF CONVECTIVE INITIATION WITHIN THE FORECAST AREA BY MID TO
LATE AFTERNOON. THIS WILL ONCE AGAIN BE A STRONGLY UNSTABLE AIRMASS
WITH AROUND 40 KTS OF DEEP LAYER SHEAR. IT MAY BE MORE DIFFICULT TO
MAINTAIN DISCRETE CONVECTION GIVEN THE ORIENTATION OF THE BOUNDARY
BUT WITH SUPERCELL ACTIVITY POSSIBLE AT LEAST INITIALLY...ALL MODES
OF SEVERE WEATHER WOULD SEEM PLAUSIBLE...WITH A FOCUS ACROSS NORTH
CENTRAL KANSAS...AND PERHAPS INTO NORTHEAST KANSAS. MAY SEE ANOTHER
ROUND OF OVERNIGHT MCS ACTIVITY DEPENDING UPON THE EVOLUTION OF THE
EVENING THUNDERSTORMS.

WEDNESDAY MORNING MAY SEE REMNANT MCS ACTIVITY HANGING AROUND THE
FORECAST AREA BEFORE CLEARING FROM WEST TO EAST DURING THE
AFTERNOON. THE PRIMARY TROUGH AXIS WILL BE APPROACHING FROM THE WEST
BY WEDNESDAY AFTERNOON WITH STRONG ASCENT OVERSPREADING WESTERN
KANSAS. WIDESPREAD THUNDERSTORMS WILL DEVELOP AMIDST THE ASCENT TO
THE WEST...AND WHILE THE STORM MOTION WILL HAVE QUITE A BIT OF A
NORTHERLY COMPONENT TO IT...THIS ACTIVITY WILL SPREAD EAST INTO
NORTH CENTRAL KANSAS BY EVENING...AND LIKELY GROW UPSCALE INTO AN
MCS WITH SEVERE POTENTIAL ON WEDNESDAY NIGHT.

THE THURSDAY FORECAST WILL BE GREATLY INFLUENCED BY CONVECTION LEFT
OVER FROM WEDNESDAY NIGHT. THERE ALSO SEEMS TO BE A CHANCE FOR
WIDESPREAD THUNDERSTORMS THROUGH THE MORNING AND PERHAPS EARLY
AFTERNOON AS THE STRONG SHORT WAVE TROUGH AXIS PASSES OVERHEAD.
SHOULD SEE SUBSIDENCE IMMEDIATELY BEHIND THIS WAVE THOUGH WHICH
COULD ALLOW SOME ATMOSPHERIC RECOVERY BY LATE AFTERNOON/EVENING.
CONVECTIVE MODE AND EVOLUTION ARE THE GREATEST QUESTION MARK ON
THURSDAY AS THERE IS SUFFICIENT INSTABILITY AND MORE THAN ENOUGH
WIND SHEAR TO SUPPORT POTENTIAL FOR AT LEAST ONE...IF NOT MULTIPLE
ROUNDS OF STRONG TO SEVERE THUNDERSTORMS. SHEAR PROFILES EXHIBIT
MUCH TURNING WITH HEIGHT...SUGGESTIVE OF ENHANCED LOW LEVEL
MESOCYCLONE POTENTIAL.

THURSDAY NIGHT THE MAIN UPPER LEVEL LOW CONTINUES TO ADVANCE
EASTWARD INTO THE NORTHERN PLAINS WHILE SHORTWAVES ROTATE FURTHER
SOUTH ACROSS OUR AREA. IT SEEMS THAT EACH SHORTWAVE WILL BRING THE
CHANCE OF SEVERE STORMS WITH INSTABILITY AND SHEAR IN
PLACE...ESPECIALLY THURSDAY NIGHT AS THE ECMWF WANTS TO INCREASE
THE INSTABILITY ACROSS KANSAS AND DEVELOP THUNDERSTORMS WHICH WILL
MOVE THROUGH NORTHEAST KANSAS. ON FRIDAY IT APPEARS THE MAIN
ENERGY WILL DRAG A FRONT ACROSS THE AREA BRINGING MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS WHICH MAY BE SEVERE. PRECIP LOOKS TO
CONTINUE INTO SATURDAY AS THE FRONT SLIDES SOUTHEAST. THE SEVERE
THREAT LOOKS TO REMAIN SOUTH OF THE AREA AT THIS POINT WITH BETTER
INSTABILITY ACROSS OKLAHOMA. THE MODELS BEGIN TO DISAGREE ON HOW
THE UPPER LEVEL ENERGY LIFTS NORTHEAST WITH THE GFS KEEPING MORE
ENERGY ACROSS THE SOUTHWEST AND IS SLOWER MOVING THE FRONT AND
PRECIP OUT OF THE AREA. THEREFORE HAVE KEPT THE POPS THROUGH
SUNDAY MORNING FOR OUR SOUTHEAST AREAS. SUNDAY AND BEYOND LOOK TO
BE DRY AS THE MAIN ENERGY WORKS INTO THE GREAT LAKES REGION.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 739 PM CDT MON MAY 27 2013

CLUSTER OF CONVECTION OVER NORTH CENTRAL KANSAS WILL CONTINUE TO
DEVELOP/SPREAD EASTWARD OVERNIGHT AND IS EXPECTED TO PASS THROUGH THE
TERMINALS IN THE 03Z-08Z TIMEFRAME WITH MVFR CIGS/VSBYS AND GUSTY
WINDS. VFR CONDITIONS RETURNING TO THE TAF SITES BY 14Z IN THE WAKE
OF CONVECTION WITH SOUTH WINDS 10-15 KTS.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

MESOSCALE...BARJENBRUCH
SHORT TERM...LEIGHTON
LONG TERM...BARJENBRUCH/SANDERS
AVIATION...63

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
316 PM CDT MON MAY 27 2013

KSZ008>012-020>024-026-034>040-054>056-058-059-282030-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
316 PM CDT MON MAY 27 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL...NORTH
CENTRAL AND NORTHEAST KANSAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS WILL DEVELOP IN CENTRAL KANSAS AND MOVE EAST IN THE
LATE AFTERNOON THROUGH THE NIGHT TIME HOURS. SOME OF THESE STORMS
MAY BE SEVERE...WITH HAIL UP TO THE SIZE OF BASEBALLS...WIND GUSTS
UP TO 70 MPH...AND A FEW TORNADOES POSSIBLE...PARTICULARLY IN
NORTH CENTRAL KANSAS FROM 5 PM THROUGH 11 PM.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THUNDERSTORMS ARE POSSIBLE FOR THE ENTIRE AREA FROM TUESDAY
THROUGH SATURDAY...WITH AT LEAST SOME CHANCE FOR SEVERE WEATHER
EACH DAY.

TUESDAY AFTERNOON AND TUESDAY NIGHT WILL SEE THE BEST SEVERE
WEATHER POTENTIAL IN NORTH CENTRAL AND NORTHEAST KANSAS. ANY
SEVERE THUNDERSTORMS ON WEDNESDAY WOULD LIKELY IMPACT NORTH
CENTRAL KANSAS DURING THE EVENING HOURS...AND SPREAD ACROSS THE
REMAINDER OF EASTERN KANSAS ON WEDNESDAY NIGHT.

THE ENTIRE FORECAST AREA MAY SEE MULTIPLE ROUNDS OF THUNDERSTORMS
FROM THURSDAY MORNING THROUGH FRIDAY...WITH SEVERE WEATHER
POSSIBLE THROUGH THE PERIOD. THE THUNDERSTORM CHANCES WILL
GRADUALLY DECREASE FROM NORTHWEST TO SOUTHEAST FRIDAY NIGHT
THROUGH SATURDAY.

WITH SEVERAL ROUNDS OF HEAVY RAINFALL POSSIBLE...THE THREAT FOR
FLOODING MAY BE ON THE INCREASE BY LATE IN THE WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS WILL LIKELY BE NEEDED THIS EVENING AND ARE ENCOURAGED TO
REPORT ANY SEVERE WEATHER INCLUDING HAIL...WIND...AND TORNADOES TO THE
NATIONAL WEATHER SERVICE OR LAW ENFORCEMENT.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TOPEKA KS
314 PM CDT MON MAY 27 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0312 PM     HEAVY RAIN       4 S OZAWKIE             39.18N 95.48W
05/27/2013  M2.38 INCH       JEFFERSON          KS   TRAINED SPOTTER

            RAINFALL TOTAL AS OF 2PM

&&

KSANDERS