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.
Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
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.
Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
5 %
69,334
4,147,416
Omaha, NE...Lincoln, NE...Des Moines, IA...Sioux Falls, SD...Rochester, MN...
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.
Hail Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
5 %
184,746
9,989,889
Omaha, NE...Lincoln, NE...Madison, WI...Des Moines, IA...Sioux Falls, SD...
SPC AC 191258
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0758 AM CDT FRI SEP 19 2014
VALID 191300Z - 201200Z
...NO SVR TSTM AREAS FORECAST...
...SUMMARY...
A FEW THUNDERSTORMS MAY BECOME MARGINALLY SEVERE THIS EVENING AND
TONIGHT FROM EASTERN NEBRASKA INTO PARTS OF MICHIGAN...AND OVER
NORTHERN MINNESOTA.
...SYNOPSIS...
GENERAL DAY-1 UPPER-AIR PATTERN OVER CONUS WILL BE DOMINATED BY
THREE PRINCIPAL REGIMES--
1. SLOWLY RISING HEIGHTS OVER 4-CORNERS REGION SWD OVER NWRN MEX...
2. HIGH-AMPLITUDE SHORTWAVE TROUGH -- NOW EVIDENT IN
MOISTURE-CHANNEL IMAGERY FROM SERN ORE ACROSS NRN/CENTRAL CA AND
ADJOINING PAC WATERS--FCST TO EVOLVE INTO CLOSED AND TEMPORARILY
CUT-OFF LOW OFFSHORE SRN CA...AND
3. PROGRESSIVE/LOW-AMPLITUDE SHORTWAVES TRAVERSING NRN STREAM NEAR
CANADIAN BORDER.
WITHIN THAT NRN BRANCH...SHORTWAVE TROUGH THAT HAD BEEN PHASED WITH
CA SYSTEM IS BREAKING EWD AND WILL CROSS NRN PLAINS TODAY...BEFORE
REACHING MN/IA AROUND END OF PERIOD. THIS FEATURE SHOULD START TO
ACCELERATE EWD LATE IN PERIOD AS UPSTREAM PERTURBATION -- CURRENTLY
EVIDENT OVER NRN BC -- TURNS SEWD ACROSS NRN AB AND
AMPLIFIES...REACHING CENTRAL/SRN SK BY 12Z.
11Z SFC ANALYSIS SHOWED COLD FRONT ASSOCIATED WITH LEADING
NRN-STREAM PERTURBATION FROM SRN MB SWWD ACROSS CENTRAL
ND...W-CENTRAL/SWRN SD...AND CENTRAL WY. FRONT IS FCST TO MOVE EWD
ACROSS NRN PLAINS AND UPPER MIDWEST REGION THROUGH
PERIOD....REACHING NWRN MN...E-CENTRAL SD...SWRN NEB AND CO/WY
BORDER AROUND 00Z. BY 12Z...FRONT SHOULD REACH CENTRAL/WRN LS...WRN
WI...ERN NEB...AND E-CENTRAL/NERN CO.
...UPPER MIDWEST TO CENTRAL PLAINS...
ALTHOUGH CONDITIONAL SEVERE THREAT WILL BEGIN DURING LATE
AFTN...MORE CERTAIN CONVECTIVE POTENTIAL IS EXPECTED TO DEVELOP
AFTER DARK ALONG/AHEAD OF SFC COLD FRONT...WITH ISOLATED LARGE HAIL
AND DAMAGING GUSTS POSSIBLE.
LLJ NOW EXTENDING FROM CENTRAL PLAINS TO SRN MN IS EXPECTED TO SHIFT
EWD ACROSS UPPER MIDWEST AND UPPER MS VALLEY. DURING TIME FRAME
FROM ABOUT 23-02Z...FAVORABLY LLJ-ENLARGED HODOGRAPHS ARE EXPECTED
TO BECOME JUXTAPOSED WITH RELATIVELY MINIMIZED MLCINH AND PLUME OF
60S F PREFRONTAL SFC DEW POINTS...PRIMARILY FROM SRN MN ACROSS MUCH
OF IA. MODIFIED FCST SOUNDINGS SUPPORT FAVORABLE PARAMETER SPACE
FOR SUPERCELLS OR BOWS...AS THOSE FACTORS COMBINED WITH END-STAGE
AFTN BOUNDARY-LAYER WARMTH WILL YIELD UP TO 1500-2000 J/KG
MLCAPE...40-50 KT EFFECTIVE-SHEAR MAGNITUDES...AND 350-500 J/KG
EFFECTIVE SRH. HOWEVER...SUBSTANTIAL/SFC-BASED TSTM DEVELOPMENT IS
VERY UNCERTAIN...GIVEN STG MLCINH EXPECTED TO DEVELOP THROUGH TODAY
RELATED TO EML ADVECTING OVER AREA.
MIDLEVEL HEIGHT FALLS...APCHG COOLING ALOFT AHEAD OF LEADING
SHORTWAVE TROUGH...CONVERGENCE NEAR FRONT...AND WAA/ISENTROPIC
LIFT...SHOULD CONTRIBUTE TO GREATER UNCONDITIONAL TSTM POTENTIAL
THIS EVENING INTO OVERNIGHT HOURS...SHIFTING EWD ACROSS MRGL-SVR
PROBABILITY AREAS. ELEVATED MUCAPE MAY EXCEED 2000 J/KG...WITH
ISOLATED LARGE HAIL BEING PRIMARY CONCERN TONIGHT.
SEPARATE AREA OF ISOLATED TO WIDELY SCATTERED TSTMS MAY DEVELOP LATE
AFTN INTO EVENING OVER NRN MN AND NERN ND...IN WAKE OF
ONGOING/MORNING CONVECTION. ELEVATED MUCAPE 1000-1500 J/KG AND
35-45 KT EFFECTIVE-SHEAR MAGNITUDES MAY SUPPORT SPORADIC HAIL...SOME
OF WHICH COULD REACH SVR LIMITS.
..EDWARDS/MARSH.. 09/19/2014
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z