Day 1 Severe Weather Outlook

This page will automatically refresh every 15 minutes

Day 1 Convective Outlook/Bulletin

Most recent data in the last 24 hours

  KWNS  26May12 19:00Z  

    
    589 
    ACUS01 KWNS 261934  WSI DDS:261934
    SWODY1
    SPC AC 261933
    
    DAY 1 CONVECTIVE OUTLOOK  
    NWS STORM PREDICTION CENTER NORMAN OK
    0233 PM CDT SAT MAY 26 2012
    
    VALID 262000Z - 271200Z
    
    ...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF THE NRN PLAINS AS
    WELL AS THE CNTRL AND SRN HIGH PLAINS...
    
    ...THERE IS A SLGT RISK OF SVR TSTMS OVER SRN AND ERN PA...NRN
    NJ...FAR SERN NY AND WRN CT...
    
    ...PA...SRN NY...NJ...WRN CT...
    VIGOROUS CONVECTION HAS FORMED ALONG A WEAK BOUNDARY AND WITHIN A
    VERY MOIST AND UNSTABLE AIR MASS. MODIFIED MODEL SOUNDINGS FOR THE
    AREA INDICATE CONTINUED POTENTIAL FOR TALL MULTICELL STORMS WITH
    BOTH HAIL AND DOWNBURST POTENTIAL. SOUNDING ANALOGS ARE CURRENTLY
    MATCHING THIS ENVIRONMENT TO A TYPICAL JUNE PROFILE IN THE SERN
    STATES. DESPITE WEAK WIND PROFILES...THE HODOGRAPH APPEARS FAVORABLE
    FOR MINOR STORM TILTING ALOFT AND THE RE-INGESTION OF HAIL EMBRYOS.
    PRESENCE OF HAIL IN THE DOWNDRAFT MAY RESULT IN FURTHER
    COOLING/NEGATIVE BUOYANCY AND ENHANCED WET MICROBURSTS.
    THEREFORE...HAVE UPGRADED TO A SLIGHT RISK.
    
    ...SRN HIGH PLAINS...
    STRONG HEATING WILL CONTINUE TO STEEPEN LAPSE RATES...WITH SCATTERED
    CONVECTION LIKELY IN THE NEXT FEW HOURS OVER QUITE A LARGE AREA.
    THIS ACTIVITY WILL BE RATHER UNFOCUSED BUT WILL POSE A MARGINAL WIND
    AND HAIL THREAT. FOR MORE INFORMATION...SEE MESOSCALE DISCUSSION
    0910.
    
    ..JEWELL.. 05/26/2012
    
    .PREV DISCUSSION... /ISSUED 1141 AM CDT SAT MAY 26 2012/
    
    ...CORRECTED FOR TYPOS/WORDING...
    
    ...CNTRL PLAINS TO MIDWEST...
    A DIFFICULT AND UNCERTAIN FORECAST SCENARIO TODAY WITH MANY FACTORS
    POTENTIALLY CONTRIBUTING TO SIGNIFICANT TSTM DEVELOPMENT AND OTHER
    FACTORS POSSIBLY HINDERING THIS DEVELOPMENT. LARGE SCALE PATTERN
    FEATURES A DEEP UPPER TROUGH ACROSS THE WEST AND A STRONG RIDGE
    DOMINATING THE SOUTH AND SOUTHEAST. IN BETWEEN THESE TWO LARGE SCALE
    FEATURES...DEEP-LAYER SLY FLOW HAS CONTRIBUTED TO COPIOUS LOW LEVEL
    MOISTURE TRANSPORT ACROSS THE GREAT PLAINS/MIDWEST WHILE AT THE SAME
    TIME RESULTING IN AN EXPANSIVE ELEVATED MIXED LAYER AIRMASS/CAP THAT
    WILL INHIBIT MOST CONVECTIVE DEVELOPMENT IN THE ABSENCE OF STRONG
    FORCED ASCENT AND/OR DIABATIC INFLUENCES.
    
    STORM SCALE GUIDANCE FROM 00Z...THE 12Z WRF-NMM...AND THE 12Z
    NAM-WRF MODELS ALL DEPICT SOME POTENTIAL FOR LATE AFTERNOON STORM
    INITIATION ALONG OR IMMEDIATELY NORTH OF THE WARM FRONT OVER IA.
    THIS DEVELOPMENT MAY BE A RESULT OF WEAK DCVA ACCOMPANYING A SERIES
    OF LOW AMPLITUDE SHORT WAVES TRAVELING WITHIN THE DEEP-LAYER
    MERIDIONAL FLOW ACROSS THE PLAINS. THESE MAY CREST THE RIDGE AXIS
    COINCIDENT WITH A MAXIMUM IN DIURNAL HEATING/DESTABILIZATION AND
    CONTRIBUTE TO TSTM DEVELOPMENT IN A VERY UNSTABLE AIRMASS. RESULTING
    CONVECTION COULD THEN ORGANIZE INTO A FORWARD PROPAGATING MCS WITH
    HAIL AND WIND SPREADING EWD ALONG THE INSTABILITY GRADIENT/WARM
    FRONT FROM IA TO THE UPPER MIDWEST. THUS PARTS OF THESE AREAS HAVE
    BEEN INCLUDED IN A SLGT RISK WITH THIS UPDATE.
    
    EVEN GREATER UNCERTAINTY IN A SCENARIO EXISTS WITH WWD EXTENT ALONG
    THE WARM FRONT ACROSS NEB. MOST GUIDANCE DEPICTS SOME DEVELOPMENT
    NEAR THE FRONT...AND ALONG THE DRYLINE/LEE TROUGH FROM NERN CO
    ACROSS PARTS OF WRN/CNTRL KS BY EVENING. ANY STORMS THAT CAN
    OVERCOME INHIBITION IN THESE AREAS WILL EXIST IN A KINEMATIC REGIME
    SUPPORTIVE OF SUPERCELLS. HAIL AND HIGH WINDS WILL BE POSSIBLE AND
    TORNADO POTENTIAL WILL BE ENHANCED NEAR THE WARM FRONT THAT WILL
    LIKELY BE SITUATED ACROSS NRN/CNTRL NEB. ADDITIONAL STORMS MAY
    DEVELOP NORTH OF THE FRONT ACROSS SD THROUGH THE EVENING AND POSE A
    TREAT OF LARGE HAIL.
    
    ...CNTRL HIGH PLAINS SOUTH ALONG LEE TROUGH/DRYLINE TO WEST TX...
    INFLUENCE FROM THE LARGE WRN TROUGH WILL AID STORM
    DEVELOPMENT...ESPECIALLY ACROSS WY LATER THIS AFTERNOON. STORMS IN
    THIS AREA WILL GENERALLY LACK ACCESS TO GREATER INSTABILITY BUT THIS
    MAY BE COMPENSATED BY MAGNITUDE OF FORCING AND SHEAR. THE RESULT MAY
    BE A NUMBER OF HIGH BASED CELLS WITH HAIL AND SOME WIND POTENTIAL
    SPREAD NEWD FROM WY THROUGH THE EVENING.
    
    ADDITIONAL HIGH-BASED STORMS...POSSIBLY IN THE FORM OF LP SUPERCELLS
    APPEAR LIKELY ALONG THE DRYLINE SOUTH TO WEST TX. LARGE SCALE
    FORCING WILL BE MORE AMBIGUOUS HERE AND MUCH OF THIS ACTIVITY MAY BE
    DIURNALLY DRIVEN AND SHOULD BEGIN TO DECAY WITHIN AN HOUR OR TWO
    AFTER SUNSET. HAIL/WIND EVENTS AND POSSIBLY A TORNADO APPEAR
    POSSIBLE WITH THIS DEVELOPMENT.

Weather maps