SPC Jun 19, 2016 1300 UTC Day 1 Convective Outlook

June 19, 2016 | 7:40 AM CST
Outlooks

SPC 1300Z Day 1 Outlook

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0735 AM CDT SUN JUN 19 2016

VALID 191300Z - 201200Z

...THERE IS AN ENH RISK OF SVR TSTMS OVER A PORTION OF ECNTRL AND
NERN MN INTO NWRN WI...

...THERE IS A SLGT RISK OF SVR TSTMS OVER THE UPPER MIDWEST AND
WESTERN UPPER GREAT LAKES...

...THERE IS A MRGL RISK OF SVR TSTMS FROM THE CNTRL PLAINS INTO THE
UPPER GREAT LAKES...

...SUMMARY...
SCATTERED STRONG TO SEVERE STORMS ARE EXPECTED TO DEVELOP BY LATE
THIS AFTERNOON ALONG AND JUST AHEAD OF A COLD FRONT AS IT MOVES
THROUGH MINNESOTA...EASTERN SOUTH DAKOTA...AND NORTHWEST
IOWA...REACHING NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN THIS
EVENING.  A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE ACROSS
NEBRASKA TO NORTHEAST COLORADO LATE THIS AFTERNOON AND EARLY
EVENING.

...SYNOPSIS...

LARGE AREA OF HIGH PRESSURE FROM THE SWRN THROUGH CNTRL U.S. WILL
KEEP STRONGER WLYS ACROSS THE NRN TIER STATES. EMBEDDED WITHIN THIS
BELT OF STRONGER WINDS A SHORTWAVE TROUGH WILL MOVE EWD ALONG THE
CNTRL U.S./CANADIAN BORDER. IN RESPONSE...SFC LOW WILL REDEVELOP
FROM SRN SASKATCHEWAN THROUGH WRN ONTARIO WITH TRAILING COLD FRONT
MOVING SEWD INTO THE NRN PLAINS AND UPPER MS VALLEY REGIONS THIS
AFTERNOON.

...UPPER MIDWEST INTO THE WRN UPPER GREAT LAKES...

MID-UPPER 60S F DEWPOINTS CURRENTLY OVER THE CNTRL AND NRN PLAINS
WILL ADVECT NEWD THROUGH THE UPPER MS VALLEY TODAY ALONG A MIGRATORY
SWLY LLJ...CONCURRENT WITH EWD ADVECTION OF PLUME OF STEEPER
MID-LEVEL LAPSE RATES. THESE PROCESSES IN CONJUNCTION WITH STRONG
DIABATIC WARMING WILL CONTRIBUTE TO AN AXIS OF MODERATE-STRONG
INSTABILITY /2000-3000 J/KG MLCAPE/ IN PRE-FRONTAL WARM SECTOR. A
CAP ASSOCIATED WITH EWD EXPANSION OF REMNANT EML PLUME WILL LIKELY
LIMIT SFC-BASED THUNDERSTORM INITIATION UNTIL LATE AFTERNOON WHEN A
DESTABILIZING BOUNDARY LAYER...HEIGHT FALLS DOWNSTREAM FROM THE
PROGRESSIVE SHORTWAVE TROUGH...AND FRONTAL CONVERGENCE SHOULD BE
SUFFICIENT TO INITIATE STORMS. DEEP LAYER WINDS WILL STRENGTHEN IN
ASSOCIATION WITH EWD-ADVANCING MID-LEVEL JET RESULTING IN 45-55 KT
0-6 KM SHEAR SUPPORTIVE OF SUPERCELLS...ESPECIALLY WITH INITIAL
DISCRETE DEVELOPMENT. LOW-LEVEL WINDS WILL VEER WITH TIME AS THE LLJ
SHIFTS EWD. HOWEVER...0-2 KM HODOGRAPHS WILL REMAIN SUFFICIENT FOR A
FEW STORMS TO DEVELOP LOW-LEVEL MESOCYCLONES ALONG WITH AN ATTENDANT
THREAT FOR A COUPLE OF TORNADOES...BUT PRIMARY THREATS ARE EXPECTED
TO BE LARGE HAIL AND DAMAGING WIND BEFORE ACTIVITY BEGINS TO
DECREASE BY LATE EVENING AS THE BOUNDARY LAYER STABILIZES.

...NEB TO NORTHEAST CO...

GIVEN CLOSER PROXIMITY TO THE BROAD/FLAT RIDGING ALOFT WITH A
STRONGER CAP...MODELS SUGGEST STORM COVERAGE SHOULD BE LESS WITH
SOUTHWESTWARD EXTENT ALONG THE COLD FRONT.  MODERATE INSTABILITY
SHOULD ALLOW A FEW STORMS THAT DO FORM TO BE CAPABLE OF PRODUCING
ISOLATED HAIL AND/OR STRONG WIND GUSTS.

..DIAL/JIRAK.. 06/19/2016