Sep 1, 2014 0100 UTC Day 1 Convective Outlook
Updated: Mon Sep 1 00:59:03 UTC 2014 (20140901 0100Z Day 1 shapefile | 20140901 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140901 0100 UTC Day 1 Outlook Graphic
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 156,592 12,371,354 Kansas City, MO...Omaha, NE...Minneapolis, MN...Wichita, KS...St. Paul, MN...
Probabilistic Tornado Graphic
20140901 0100 UTC Day 1 Tornado Probabilities Graphic
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
5 % 33,671 2,066,284 Omaha, NE...Des Moines, IA...Council Bluffs, IA...Ames, IA...West Des Moines, IA...
2 % 103,903 15,766,427 Boston, MA...Kansas City, MO...Minneapolis, MN...St. Paul, MN...Lincoln, NE...
Probabilistic Damaging Wind Graphic
20140901 0100 UTC Day 1 Damaging Wind Probabilities 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
30 % 56,774 3,761,468 Kansas City, MO...Omaha, NE...Des Moines, IA...Kansas City, KS...Topeka, KS...
15 % 99,137 8,595,996 Minneapolis, MN...Wichita, KS...St. Paul, MN...Lincoln, NE...Overland Park, KS...
5 % 189,584 16,978,740 Boston, MA...Washington, DC...Arlington, VA...Providence, RI...Alexandria, VA...
Probabilistic Large Hail Graphic
20140901 0100 UTC Day 1 Large Hail Probabilities 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
SIG SEVERE 32,761 1,248,900 Omaha, NE...Topeka, KS...Lawrence, KS...Council Bluffs, IA...Bellevue, NE...
30 % 28,219 1,264,882 Omaha, NE...Topeka, KS...Council Bluffs, IA...Bellevue, NE...Salina, KS...
15 % 128,638 11,118,645 Kansas City, MO...Minneapolis, MN...Wichita, KS...St. Paul, MN...Lincoln, NE...
5 % 166,121 4,064,668 Davenport, IA...Columbia, MO...Duluth, MN...Sioux City, IA...Dubuque, IA...
   SPC AC 010059

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0759 PM CDT SUN AUG 31 2014

   VALID 010100Z - 011200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS VALLEY TO
   KANSAS...

   ...SUMMARY...
   SCATTERED STRONG TO SEVERE STORMS WILL CONTINUE THIS EVENING INTO
   TONIGHT ALONG A COLD FRONT FROM MINNESOTA AND WESTERN WISCONSIN
   SOUTHWESTWARD ACROSS EASTERN NEBRASKA...IOWA...CENTRAL AND EASTERN
   KANSAS INTO NORTHERN AND WESTERN MISSOURI.  LARGE HAIL...DAMAGING
   WINDS...AND A COUPLE OF TORNADOES ARE EXPECTED WITH THIS ACTIVITY. 
   A FEW STRONG TO SEVERE STORMS REMAIN POSSIBLE FOR 1 TO 2 HOURS
   ACROSS THE MID-ATLANTIC STATES AND PART OF EASTERN NEW ENGLAND.

   ...UPPER MS VALLEY TO KS/MO...
   A PROGRESSIVE SHORTWAVE TROUGH...CURRENTLY MOVING EWD INTO THE
   CENTRAL PLAINS PER SATELLITE IMAGERY...WILL BEGIN TO TAKE ON A
   NEGATIVE TILT AS IT REACHES THE UPPER AND MID MS VALLEY LATE IN THE
   FORECAST PERIOD.  FORCING FOR ASCENT ATTENDANT TO THIS MIDLEVEL
   FEATURE AND THE EXIT REGION OF AN ACCOMPANYING 500-MB 50-60 KT JET
   AND A STRENGTHENING/VEERING 45-60 KT SSWLY LLJ WILL CONTINUE TO
   PROVE FAVORABLE FOR UPSCALE GROWTH OF A LINEAR-TYPE MCS.  MOSAIC
   RADAR IMAGERY SUGGESTS THIS SCENARIO IS ALREADY UNDERWAY FROM WRN IA
   THROUGH SERN NEB INTO KS ALONG THE COLD FRONT.  STORM MODE SHOULD
   FAVOR PRIMARILY BOWING STRUCTURES /PRODUCING DAMAGING WINDS/ THROUGH
   AT LEAST THE EARLY OVERNIGHT PERIOD.  HOWEVER...STRONG EFFECTIVE
   BULK SHEAR OF 45-55 KT FROM ERN NEB INTO IA ALSO SUPPORTS A TORNADO
   THREAT.  REFERENCE TORNADO WATCHES 479 AND 482 AND SUBSEQUENT
   MESOSCALE DISCUSSIONS FOR THIS LATTER THREAT.  VERY LARGE HAIL WILL
   REMAIN POSSIBLE YET THIS EVENING ACROSS PORTIONS OF CENTRAL AND ERN
   KS INTO SWRN MO WHERE STEEP LAPSE RATES AND INSTABILITY ARE
   MAXIMIZED. 

   THE SLIGHT RISK AREA HAS BEEN EXTENDED EWD TO INCLUDE MORE OF MO AND
   SERN IA...GIVEN THE POTENTIAL FOR THE MCS TO REACH THESE AREAS LATER
   TONIGHT WITH A CONTINUED THREAT FOR MAINLY DAMAGING WINDS.

   ...ERN PARTS OF SRN NEW ENGLAND TO SRN MAINE...
   DESPITE WEAKENING INSTABILITY...DEEP-LAYER AND LOW-LEVEL SHEAR
   VALUES REMAIN SUFFICIENT FOR A FEW ORGANIZED STORMS THROUGH 02-03Z
   PRIOR TO THE ONGOING TSTM POTENTIAL TO EITHER DIMINISH OR MOVE
   OFFSHORE.

   ...PART OF NRN VA TO SRN NJ...
   RESIDUAL MODERATE INSTABILITY EXTENDING FROM NRN-EAST CENTRAL VA TO
   SRN NJ COULD SUPPORT A FEW STRONGER STORMS YET THIS EVENING AS A
   BROKEN BAND OF TSTMS MOVES EWD ACROSS THIS REGION.  AS THE BOUNDARY
   LAYER STABILIZES /GIVEN THE LOSS OF DAYTIME HEATING/...THE OVERALL
   THREAT FOR ISOLATED STRONGER WIND GUSTS REACHING THE SURFACE WILL
   CONCURRENTLY DIMINISH.  THIS THREAT DOES NOT WARRANT SEVERE WIND
   PROBABILITIES GREATER THAN 5 PERCENT WITH THIS OUTLOOK ISSUANCE.

   ..PETERS.. 09/01/2014

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z