Jun 21, 2015 0600 UTC Day 2 Convective Outlook
Updated: Sun Jun 21 06:02:39 UTC 2015 (20150621 0600Z Day 2 shapefile | 20150621 0600Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150621 0600 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 77,626 8,484,999 Milwaukee, WI...Madison, WI...Grand Rapids, MI...Lansing, MI...Flint, MI...
SLIGHT 135,820 18,075,502 Chicago, IL...Detroit, MI...Minneapolis, MN...Toledo, OH...St. Paul, MN...
MARGINAL 214,636 27,032,744 Indianapolis, IN...Columbus, OH...Cleveland, OH...Omaha, NE...Cincinnati, OH...
Probabilistic Graphic
20150621 0600 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 113,246 15,736,812 Milwaukee, WI...Minneapolis, MN...St. Paul, MN...Madison, WI...Grand Rapids, MI...
30 % 75,721 8,339,681 Milwaukee, WI...Madison, WI...Grand Rapids, MI...Lansing, MI...Flint, MI...
15 % 134,930 17,166,107 Detroit, MI...Minneapolis, MN...Toledo, OH...St. Paul, MN...Rockford, IL...
5 % 217,184 27,717,785 Chicago, IL...Indianapolis, IN...Columbus, OH...Cleveland, OH...Omaha, NE...
   SPC AC 210602

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0102 AM CDT SUN JUN 21 2015

   VALID 221200Z - 231200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS ACROSS PARTS OF FAR SE
   MN...WI...LAKE MICHIGAN AND LOWER MI...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MS
   VALLEY AND GREAT LAKES REGION...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF THE NRN
   PLAINS...MID TO UPPER MS VALLEY...GREAT LAKES REGION AND NRN OH
   VALLEY...

   ...SUMMARY...
   SEVERE THUNDERSTORMS WILL BE POSSIBLE ACROSS THE UPPER MISSISSIPPI
   VALLEY AND GREAT LAKES REGION ON MONDAY WHERE A FEW
   TORNADOES...DAMAGING WIND GUSTS AND ISOLATED LARGE HAIL MAY OCCUR. A
   THREAT FOR STRONG TORNADOES AND WIND GUSTS OF GREATER THAN 65 KNOTS
   WILL BE POSSIBLE. MARGINALLY SEVERE THUNDERSTORMS MAY OCCUR ACROSS
   THE MID MISSOURI VALLEY...MID TO UPPER MISSISSIPPI VALLEY AND
   NORTHERN OHIO VALLEY.

   ...UPPER MS VALLEY/GREAT LAKES REGION...
   A VIGOROUS UPPER-LEVEL TROUGH WILL MOVE EWD ACROSS THE NRN PLAINS
   INTO THE UPPER MS VALLEY ON MONDAY AS AN IMPRESSIVE 60 TO 80 KT
   MID-LEVEL JET OVERSPREADS THE UPPER MS VALLEY AND GREAT LAKES
   REGION. AT THE SFC...A LOW IS FORECAST TO MOVE QUICKLY NEWD FROM THE
   MID MO VALLEY INTO THE GREAT LAKES REGION AS A COLD FRONT ADVANCES
   SEWD INTO THE UPPER MS VALLEY. AHEAD OF THE FRONT...A VERY MOIST
   AIRMASS SHOULD BE IN PLACE WITH SFC DEWPOINTS IN THE LOWER 70S F
   WHICH SHOULD ENABLE MODERATE TO STRONG INSTABILITY TO DEVELOP ACROSS
   MUCH OF THE MID TO UPPER MS VALLEY BY AFTERNOON. 
   IN ADDITION TO THE STRONG INSTABILITY...MODEL FORECASTS SHOW
   IMPRESSIVE SHEAR PROFILES AND AN UPPER-LEVEL SYSTEM THAT APPEARS
   QUITE ORGANIZED WITH A WELL-DEFINED LOW TO MID-LEVEL JET COUPLET.
   THIS COULD RESULT IN A SIGNIFICANT EVENT OCCURRING ACROSS PARTS OF
   THE UPPER MS VALLEY AND GREAT LAKES REGION ON MONDAY. CONSIDERING
   THE NAM...GFS AND ECMWF MODELS...THE NAM AND GFS APPEAR TO THE BE
   MOST AGGRESSIVE SOLUTIONS WHILE THE ECMWF IS SLIGHTLY MORE
   CONSERVATIVE CONCERNING THE AMOUNT OF INSTABILITY...SHEAR AND
   ORGANIZATION WITH THE UPPER-LEVEL SYSTEM. MANY PROBLEMS EXIST FOR
   DETERMINING THE MOST LIKELY CORRIDOR FOR SEVERE INCLUDING 1) HOW
   MORNING CONVECTION WILL IMPACT THE SETUP IN THE AFTERNOON AND 2) HOW
   FAR NORTH WILL THE CAPPING INVERSION IMPEDE CONVECTIVE DEVELOPMENT.

   THE CURRENT THINKING IS THAT A MORNING MCS WITH WIND DAMAGE
   POTENTIAL WILL TRACK ESEWD FROM ERN MN AND ERN IA ACROSS SRN
   WI...NRN IL AND INTO IND AROUND MIDDAY. FURTHER WEST BEHIND THE
   MORNING MCS...AN AXIS OF STRONG INSTABILITY WILL DEVELOP FROM NRN MO
   NWD INTO ERN IA WITH NEW CONVECTION INITIATING ON THE NRN END OF THE
   STRONG INSTABILITY IN FAR SE MN AND NWRN WI DURING THE AFTERNOON.
   THIS CONVECTION SHOULD MOVE EWD AND GRADUALLY GROW UPSCALE. NAM
   FORECAST SOUNDINGS AT 21Z ON MONDAY FOR MADISON WI SHOW IMPRESSIVE
   THERMODYNAMICS AND SHEAR PROFILES WITH MLCAPE ABOVE 4000 J/KG AND
   0-6 KM SHEAR FROM 60 TO 70 KT. THIS WOULD BE VERY FAVORABLE FOR
   SEVERE STORMS INCLUDING SUPERCELLS. IT SEEMS POSSIBLE THAT A CLUSTER
   OF SUPERCELLS COULD ORGANIZE DURING THE MID TO LATE
   AFTERNOON...MOVING EWD ACROSS CNTRL AND ERN WI AND CROSSING LAKE MI
   INTO LOWER MI BY EARLY EVENING. STRONG LOW-LEVEL SHEAR COULD SUPPORT
   A THREAT FOR STRONG TORNADOES AND A LONG-TRACK TORNADO CAN NOT BE
   RULED OUT. THE OTHER POSSIBILITY IS FOR A SEVERE WIND PRODUCING
   LINEAR MCS THAT MOVES QUICKLY ESEWD ACROSS WI DURING THE LATE
   AFTERNOON REACHING LOWER MI BY EARLY EVENING. DUE TO THE POSSIBILITY
   OF A HIGH-END EVENT FOR EITHER TORNADOES OR WIND DAMAGE...THE
   ENHANCED AREA WILL BE EXPANDED TO INCLUDE MOST OF WI AND LOWER MI
   WITH THE SIGNIFICANT HATCHED AREA ALSO INCLUDING SERN MN.

   ..BROYLES.. 06/21/2015

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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z