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.
Kansas City, MO...Wichita, KS...Des Moines, IA...Overland Park, KS...Kansas City, KS...
5 %
167,404
7,609,831
Oklahoma City, OK...Tulsa, OK...Springfield, MO...Cedar Rapids, IA...Norman, OK...
Probabilistic Large Hail Graphic
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
SIG SEVERE
68,210
4,089,217
Omaha, NE...Lincoln, NE...Topeka, KS...Sioux City, IA...Plymouth, MN...
30 %
49,568
3,217,923
Omaha, NE...Lincoln, NE...Sioux City, IA...Plymouth, MN...Maple Grove, MN...
15 %
171,470
10,109,947
Kansas City, MO...Minneapolis, MN...Wichita, KS...St. Paul, MN...Des Moines, IA...
5 %
168,985
7,640,962
Oklahoma City, OK...Tulsa, OK...Springfield, MO...Cedar Rapids, IA...Norman, OK...
SPC AC 220604
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0104 AM CDT SAT AUG 22 2015
VALID 221200Z - 231200Z
...THERE IS AN ENH RISK OF SVR TSTMS FROM CENTRAL AND SOUTHERN MN
THROUGH WESTERN IA...EXTREME EASTERN NEB...AND EXTREME NORTHWEST
MO...
...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE ENH RISK AND
SOUTH THROUGH WESTERN MO AND EASTERN/CENTRAL KS...
...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE SLGT RISK AND
SOUTH INTO CENTRAL MO...NORTHWEST AR...NORTHERN AND CENTRAL OK...TO
WESTERN KS...
...SUMMARY...
SCATTERED SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND
EVENING ACROSS THE UPPER MIDWEST...PORTIONS OF THE MIDDLE AND LOWER
MISSOURI VALLEY INTO CENTRAL AND EASTERN KANSAS. DAMAGING
WINDS...LARGE HAIL...AND A FEW TORNADOES WILL BE THE SEVERE-WEATHER
THREATS.
...SYNOPSIS...
AN UNSEASONABLY STRONG MID- TO UPPER-LEVEL TROUGH IS EXPECTED TO
EVOLVE ACROSS THE NORTHERN PLAINS INTO THE UPPER MS VALLEY THIS
FORECAST PERIOD...WITH STRENGTHENING DEEP-LAYER WIND FIELDS AND AN
EXPECTED PRE-FRONTAL ENVIRONMENT BECOMING MOIST WITH MODERATE TO
VERY STRONG INSTABILITY. OPERATIONAL DETERMINISTIC MODELS ARE QUITE
SIMILAR WITH THE TRACK AND TIMING OF THIS TROUGH WITH DEEPENING AND
CLOSED LOW FORMATION OVER NORTHERN MN AND ADJACENT SOUTHERN
CANADA...AND THE TROUGH BECOMING NEGATIVELY TILTED BY 12Z SUNDAY
ACROSS THE UPPER MS VALLEY. 60-120-METER 500-MB HEIGHT FALLS PER 12
HOURS ARE EXPECTED ACROSS ND/SD THROUGH THIS AFTERNOON...WITH
STRONGER 500-MB HEIGHT FALLS /120-180-METERS IN 12 HOURS/ ACROSS THE
UPPER MS VALLEY AFTER 22/00Z. THE EVOLUTION OF THE MID- TO
UPPER-LEVEL TROUGH WILL SUPPORT A DEEPENING SURFACE LOW TRACKING
FROM CENTRAL SD INTO NORTHWEST ONTARIO. A TRAILING COLD FRONT WILL
MOVE STEADILY EAST/SOUTHEAST INTO THE UPPER MIDWEST AND MID-MISSOURI
VALLEY THIS AFTERNOON...EXTENDING FROM WRN MN THROUGH NORTHWEST
IA...SOUTHEAST NEB TO NORTHWEST KS BY MID-LATE AFTERNOON...AND THEN
FROM NORTHEAST MN/NORTHWEST WI TO EASTERN IA...CENTRAL MO AND
CENTRAL OK BY 12Z SUNDAY.
...UPPER MIDWEST TO LOWER MO VALLEY AND KS...
LOW-LEVEL MOISTURE WILL RETURN POLEWARD IN ADVANCE OF THE COLD FRONT
TODAY WITH MIDDLE 60S TO NEAR 70 F SURFACE DEW POINTS IN PLACE BY
LATE AFTERNOON. THIS COMBINED WITH AN EXPANDING EML PLUME WITH
700-500-MB LAPSE RATES OF 8-9 C/KM ACROSS THE CENTRAL PLAINS...MID
MISSOURI VALLEY INTO MN WILL RESULT IN MUCAPE 2000-3000 J/KG NORTH
TO SOUTH ACROSS THE UPPER MIDWEST TO EASTERN NEB/WESTERN IA...WHILE
VALUES AT OR ABOVE 3000 J/KG WILL BE POSSIBLE ACROSS KS BY LATE
AFTERNOON.
DESTABILIZATION ACROSS EASTERN ND THIS MORNING MAY ALLOW FOR A FEW
STRONG TO SEVERE STORMS. ALTHOUGH THE EASTWARD EXTENT OF THE EML
SHOULD INITIALLY CAP THE WARM SECTOR...NEW STORM DEVELOPMENT COULD
OCCUR BY MID-AFTERNOON ACROSS WESTERN/CENTRAL MN INTO NORTHWEST IA
AND NORTHEAST NEB AS DPVA ATTENDANT TO A LEAD IMPULSE SPREADS ACROSS
THESE AREAS. INITIAL STORM MODE THIS AFTERNOON IS EXPECTED TO BE
DISCRETE SUPERCELLS GIVEN ORTHOGONAL DEEP-LAYER SHEAR VECTORS OF
35-50 KT ACROSS THE COLD FRONT...WITH AN INCREASE IN STORM
COVERAGE/INTENSITY AS STRONGER FORCING FOR ASCENT ARRIVES BY 22/00Z
WITH THE APPROACHING STRONG TROUGH. ALL SEVERE HAZARDS ARE EXPECTED
WITH THE INITIAL DISCRETE STORMS INCLUDING VERY LARGE HAIL AND A FEW
TORNADOES FROM CENTRAL MN TO EASTERN NEB AND WESTERN IA...GIVEN THE
STEEP MIDLEVEL LAPSE RATES...STRONG EFFECTIVE BULK SHEAR AND
ENHANCED LOW-LEVEL SHEAR ALONG A 35-45 KT SOUTHERLY LLJ ACROSS THE
CATEGORY 3 SEVERE RISK AREA. AS THE STRONGER HEIGHT FALLS/FORCING
FOR ASCENT ARRIVE THIS EVENING...STORMS WILL LIKELY GROW UPSCALE
INTO A SQUALL LINE ACROSS CENTRAL/EASTERN MN...INTO WESTERN WI AND
CENTRAL IA WITH A CONTINUED THREAT FOR DAMAGING WINDS AND SOME HAIL.
STORM DEVELOPMENT IS EXPECTED TO INCREASE ALONG THE TRAILING PORTION
OF THE COLD FRONT BY EARLY EVENING FROM SOUTHEAST NEB/NORTHWEST MO
INTO NORTHERN KS...AS THE SOUTHERN EXTENT OF HEIGHT FALLS AND UPLIFT
ALONG THE FRONT ENCOUNTER POTENTIALLY VERY STRONG INSTABILITY.
GIVEN DIFFLUENT FLOW ALOFT...ORTHOGONAL DEEP-LAYER SHEAR VECTORS
WILL BE COMMON ACROSS THIS PORTION OF THE COLD FRONT AS WELL...
SUGGESTING DISCRETE STORMS WILL BE POSSIBLE FOR THE INITIAL STORM
MODE...ESPECIALLY INTO NORTHEAST KS WHERE STORMS SHOULD FORM PRIOR
TO THE ONSET OF BOUNDARY-LAYER COOLING. VERY LARGE HAIL AND
DAMAGING WINDS WILL BE POSSIBLE WITH THESE INITIAL STORMS.
OTHERWISE...STRONG/DAMAGING WINDS SHOULD BECOME THE PRIMARY
SEVERE-WEATHER THREAT INTO THE EVENING AS THE COLD FRONT ADVANCES
SOUTH. MODELS DIFFER WITH THE SOUTHWARD EXTENT OF THIS SEVERE
WEATHER THREAT...THOUGH MUCH OF CENTRAL AND EASTERN KS AND WESTERN
MO WILL HAVE A CONDITIONAL SEVERE THREAT...GIVEN THE DEGREE OF
INSTABILITY.
..PETERS/GLEASON.. 08/22/2015
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z