Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
2 %
82,375
4,665,486
Grand Rapids, MI...Lansing, MI...Flint, MI...Kalamazoo, MI...Wyoming, MI...
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
15 %
43,851
3,936,155
Grand Rapids, MI...Lansing, MI...Flint, MI...Kalamazoo, MI...Wyoming, MI...
SPC AC 190535
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1235 AM CDT WED AUG 19 2015
VALID 191200Z - 201200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF LOWER AND
UPPER MI...
...THERE IS A MRGL RISK OF SVR TSTMS FROM A PORTION OF TX THROUGH
THE LOWER MS...TN AND OH VALLEYS...
...SUMMARY...
A FEW STRONG TO SEVERE STORMS REMAIN POSSIBLE WEDNESDAY OVER A
PORTION OF THE GREAT LAKES...LOWER OHIO VALLEY...LOWER MISSISSIPPI
AND TENNESSEE VALLEYS...AND NORTHEAST THROUGH SOUTHWEST TEXAS.
LOCALLY STRONG TO DAMAGING WIND GUSTS WILL BE THE MAIN THREATS.
...SYNOPSIS...
SYNOPTIC UPPER TROUGH NOW OVER THE CNTRL U.S. WILL ADVANCE SLOWLY
EWD TOWARD THE WRN GREAT LAKES AND OH VALLEY WEDNESDAY. SEVERAL
VORTICITY MAXIMA WILL ROTATE THROUGH THIS FEATURE INCLUDING A LEAD
IMPULSE THAT WILL MOVE THROUGH THE NRN GREAT LAKES EARLY IN THE
PERIOD. THIS FEATURE WILL BE FOLLOWED CLOSELY BY PRIMARY VORTICITY
MAXIMUM THAT WILL MOVE THROUGH NRN WI AND THE WRN UPPER PENINSULA OF
MI LATER WEDNESDAY MORNING AND EARLY AFTERNOON. PRIMARY SFC LOW WILL
CONSOLIDATE OVER THE WRN GREAT LAKES AND LIKELY BE LOCATED OVER NRN
WI BY MID DAY WITH TRAILING COLD FRONT EXTENDING SSWWD INTO NRN AND
SWRN TX. THE LOW WILL ADVANCE NWD INTO SRN ONTARIO WITH COLD FRONT
EXTENDING THROUGH THE OH VALLEY SWWD TO NEAR THE TX COAST BY THE END
OF THE PERIOD.
...GREAT LAKES AREA...
POOR MID-LEVEL LAPSE RATE AND AREAS OF CLOUDS WILL RESULT IN WEAK
INSTABILITY /400-800 J/KG MLCAPE/ IN PRE-FRONTAL WARM SECTOR...AND
THE MARGINAL THERMODYNAMIC ENVIRONMENT SHOULD SERVE AS A LIMITING
FACTOR FOR A MORE ROBUST SEVERE THREAT. LOWER-TROPOSPHERIC WINDS
WILL STRENGTHEN AS LLJ SHIFTS NEWD TO THE EAST OF CYCLONE.
HOWEVER...0-2 KM HODOGRAPHS ARE NOT FORECAST TO BE PARTICULARLY
LARGE OVER LOWER MI DUE TO THE UNIDIRECTIONAL NATURE OF THE WINDS.
NEVERTHELESS...EFFECTIVE BULK SHEAR FROM 30-40 KT WILL CHARACTERIZE
WARM SECTOR. SOME CLOUD BREAKS AND DIABATIC WARMING IS EXPECTED TO
OCCUR DURING THE DAY...AND THUNDERSTORMS SHOULD REDEVELOP OVER LOWER
MI ALONG WARM CONVEYOR BELT. PRIMARY THREAT WITH THIS ACTIVITY WILL
BE A FEW STRONG TO DAMAGING WIND GUSTS SUPPORTED BY DOWNWARD
TRANSFER OF MOMENTUM WHERE SUFFICIENT BOUNDARY LAYER DESTABILIZATION
OCCURS.
A SECONDARY AREA OF THUNDERSTORMS MAY DEVELOP OVER WRN THROUGH CNTRL
UPPER MI IN DRY SLOT REGION AND WITHIN ZONE OF ASCENT ACCOMPANYING
PRIMARY VORTICITY MAXIMUM. INSTABILITY WILL REMAIN MARGINAL IN THIS
AREA...BUT LAPSE RATES MAY BECOME SLIGHTLY BETTER THAN ACROSS LOWER
MI DUE TO COOLER MID-LEVEL TEMPERATURES IN CLOSER PROXIMITY TO UPPER
LOW. POTENTIAL WILL EXIST FOR A COUPLE OF LOW TOPPED SUPERCELLS
CAPABLE OF PRIMARILY STRONG WIND GUSTS AND A BRIEF TORNADO.
...SWRN TX THROUGH LOWER MS VALLEY...SERN STATES AND OH VALLEY...
PRE-FRONTAL WARM SECTOR WILL BECOME MARGINALLY TO MODERATELY
UNSTABLE FROM THE OH VALLEY SWWD THROUGH TX...WITH THE STRONGER
INSTABILITY EXPECTED FROM TX INTO THE LOWER MS VALLEY AREA.
THUNDERSTORMS WILL LIKELY REDEVELOP ALONG AND AHEAD OF SEWD
ADVANCING COLD FRONT WITHIN THE WEAKLY CAPPED WARM SECTOR. THESE
AREAS WILL REMAIN SOUTH AND EAST OF THE STRONGER WINDS ALOFT WITH
WEAK VERTICAL SHEAR SUPPORTIVE OF MULTICELLS CAPABLE OF MAINLY A FEW
STRONG TO DAMAGING WIND GUSTS.
..DIAL/LEITMAN.. 08/19/2015
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z