Mesoscale Discussion 896

Issued

May 25, 2012, 3:57 PM CDT (20:57 UTC)

Expired

May 25, 2012, 6:00 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

60%

The Vance AFB radar (KVNX), 87 km from the middle of the area, began a volume at 21:02 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

• Tornado Watch 298May 25, 6:50 PM CDT
• Severe Thunderstorm Watch 299May 25, 6:55 PM CDT

668 
ACUS11 KWNS 252057
SWOMCD
SPC MCD 252057 
KSZ000-OKZ000-TXZ000-252300-

MESOSCALE DISCUSSION 0896
NWS STORM PREDICTION CENTER NORMAN OK
0357 PM CDT FRI MAY 25 2012

AREAS AFFECTED...PORTIONS WRN/CENTRAL KS...WRN OK...ERN PANHANDLE OF
TX...BEAVER COUNTY IN PANHANDLE OF OK.

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 252057Z - 252300Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THREAT IS INCREASING FOR A FEW SUPERCELLS TO DEVELOP INVOF
DRYLINE AND MOVE EWD INTO WARM SECTOR...WITH ACTIVITY OVER KS
POTENTIALLY INTERACTING WITH WARM-FRONTAL ZONE.  VERY CONDITIONAL
THREAT EXTENDS EWD ALONG WARM FRONT OVER CENTRAL KS.  WITH HEIGHTS
RISING ALOFT...CAP STRENGTH AND COVERAGE OF CONVECTION STILL IS IN
QUESTION...OTHERWISE STATED WW PROBABILITIES WOULD BE HIGHER.  TWO
WWS MAY BE NEEDED -- TORNADO NEAR WARM FRONT AND SVR FARTHER S --
SINCE PRINCIPAL TORNADO THREAT APPEARS FAIRLY TIGHTLY FOCUSED.  SVR
GUSTS/HAIL ARE POSSIBLE WITH ANY SUSTAINED CONVECTION THROUGHOUT
THIS CORRIDOR.

DISCUSSION...20Z SFC MESOANALYSIS SHOWED LOW OVER GUY/LBL
AREA...WARM FRONT FROM THERE NEAR GCK-GBD-EWK-EMP-SZL-STL LINE. 
DRYLINE INTERSECTED WARM FRONT OVER HODGEMAN COUNTY KS...AND
EXTENDED JUST E OF DDC TO ERN BEAVER COUNTY OK TO HALL COUNTY TX. 
DRYLINE SHOULD BE QUASISTATIONARY ON MESO-ALPHA SCALE FOR ANOTHER
2-3 HOURS...WITH LOCALIZED WAVES/MOVEMENT...BEFORE SLGT WWD RETREAT
OCCURS STARTING AROUND 00Z.  WARM FRONT SHOULD CONTINUE MOVING NWD
ACROSS CENTRAL KS...WHILE LOWER PRESSURE MAY REMAIN SLIGHTLY SW OF
TRIPLE POINT DUE TO CONTRIBUTION TO LOW PRESSURE FROM INTENSE
HEATING BEHIND ADJOINING DRYLINE SEGMENT.  TRIPLE POINT MAY MIGRATE
NWD ACROSS W-CENTRAL KS OVER I-70 CORRIDOR THROUGH EVENING.

THERMODYNAMIC AND SHEAR PARAMETERS WILL REMAIN FAVORABLE OVER WARM
SECTOR...MAIN CONCERN BEING CAP STRENGTH AND TSTM COVERAGE. MODIFIED
RAOBS AND FCST SOUNDINGS SUGGEST STG HEATING AND MID-UPPER 60S F SFC
DEW POINTS CONTRIBUTE TO MLCAPE MAINLY IN 2000-3500 J/KG RANGE. 
MLCINH IS WEAKENING ALONG FRONT AND DRYLINE...THOUGH LESS-VIGOROUS
BOUNDARY-FORCED LIFT AND BOUNDARY-LAYER MIXING ALONG WARM-FRONT
MAKES SFC-BASED FRONTAL INITIATION LESS PROBABLE THAN ALONG DRYLINE.
 EFFECTIVE SHEAR MAGNITUDES STRENGTHEN WITH NWD EXTENT...FROM 25-35
KT RANGE OVER SERN TX PANHANDLE/SWRN OK TO 50-60 KT OVER TRIPLE
POINT.  TORNADO POTENTIAL IS MAXIMIZED WITH ANY CONVECTION INVOF
TRIPLE POINT AND NEARBY DRYLINE/WARM-FRONTAL BOUNDARY SEGMENTS. 
RELATIVELY BACKED FLOW IN THIS REGION SUPPORTS ENHANCED LOW-LEVEL
HODOGRAPHS...WHICH SHOULD ENLARGE THROUGH EARLY EVENING TO REMOVE
RELATIVE WEAKNESS OBSERVED AROUND 1-1.5 KM AGL IN HVL PROFILER
SAMPLE.  EFFECTIVE SRH 250-400 J/KG IS LIKELY IN SMALL CORRIDOR NE-E
OF TRIPLE POINT.  RELATIVELY HIGHER LFC AND WEAKER LOW-LEVEL SHEAR
ARE PRESENT AND SHOULD CONTINUE ACROSS TX/OK THREAT AREA...LOWERING
TORNADO PROBABILITIES THERE COMPARED TO NEAR WARM FRONT.

..EDWARDS/CARBIN.. 05/25/2012

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

ATTN...WFO...TOP...ICT...OUN...GID...DDC...LUB...AMA...

LAT...LON   34620068 37080046 38220027 38959922 39209858 39249797
            39019752 38589711 38059664 37439750 36799869 35489915
            34649928 34620068

Mesoscale Discussions in Kansas, 2012Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Texas, 2012Every mesoscale discussion in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.