Jul 23, 2016 1300 UTC Day 1 Convective Outlook
Updated: Sat Jul 23 13:39:35 UTC 2016 (20160723 1300Z Day 1 shapefile | 20160723 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160723 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 31,280 4,093,915 Minneapolis, MN...St. Paul, MN...Fargo, ND...Bloomington, MN...Plymouth, MN...
SLIGHT 138,113 4,975,198 Madison, WI...Rochester, MN...Duluth, MN...Waterloo, IA...Oshkosh, WI...
MARGINAL 267,528 27,449,214 Chicago, IL...Milwaukee, WI...Boston, MA...Omaha, NE...Lincoln, NE...
Probabilistic Tornado Graphic
20160723 1300 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.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
2 % 75,956 6,654,077 Minneapolis, MN...St. Paul, MN...Madison, WI...Rochester, MN...Fargo, ND...
Probabilistic Damaging Wind Graphic
20160723 1300 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.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
30 % 31,669 4,121,740 Minneapolis, MN...St. Paul, MN...Fargo, ND...Bloomington, MN...Plymouth, MN...
15 % 137,043 4,910,447 Madison, WI...Rochester, MN...Duluth, MN...Waterloo, IA...Eau Claire, WI...
5 % 269,629 27,482,287 Chicago, IL...Milwaukee, WI...Boston, MA...Omaha, NE...Lincoln, NE...
Probabilistic Large Hail Graphic
20160723 1300 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.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 101,033 6,647,601 Minneapolis, MN...St. Paul, MN...Rochester, MN...Fargo, ND...Bloomington, MN...
5 % 177,344 6,932,911 Omaha, NE...Lincoln, NE...Madison, WI...Des Moines, IA...Rockford, IL...
   SPC AC 231339

   DAY 1 CONVECTIVE OUTLOOK RESENT 1
   NWS STORM PREDICTION CENTER NORMAN OK
   0839 AM CDT SAT JUL 23 2016

   VALID 231300Z - 241200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS PORTIONS ERN DAKOTAS AND MN...

   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING ENH RISK FROM WI TO
   ERN ND...

   ...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING SLGT RISK AND
   EXTENDING TO CENTRAL HIGH PLAINS...

   ...THERE IS A MRGL RISK OF SVR TSTMS PORTIONS ERN NY AND NEW
   ENGLAND...

   ...SUMMARY...
   SCATTERED SEVERE STORMS WILL BE POSSIBLE ACROSS THE UPPER MIDWEST
   TODAY INTO THIS EVENING.  DAMAGING WIND AND LARGE HAIL WILL BE THE
   MAIN THREATS.  OTHER STRONG STORMS WITH A THREAT FOR MAINLY
   DOWNBURST WINDS ARE EXPECTED TODAY FROM EASTERN NEW YORK INTO NEW
   ENGLAND.

   ...SYNOPSIS...
   IN MID/UPPER LEVELS...MAIN BELT OF WLYS WILL PERSIST GENERALLY
   WITHIN A COUPLE HUNDRED MI EITHER SIDE OF CANADIAN BORDER...BUT WILL
   BECOME MORE AMPLIFIED THROUGH PERIOD.  HEIGHT FALLS ARE UNDERWAY
   ACROSS MUCH OF ROCKIES AND GREAT PLAINS REGIONS AS STG SHORTWAVE
   TROUGH PROCEEDS EWD ACROSS PORTIONS WY/MT.  LATTER FEATURE IS FCST
   TO MOVE ENEWD ACROSS NRN PLAINS...REACHING MB/ONT AND ND/MN BORDERS
   BY 12Z.  THAT TROUGH LIKELY WILL BE PRECEDED BY CONVECTIVELY
   ENHANCED/INDUCED MINOR PERTURBATIONS ACROSS NRN PLAINS AND UPPER
   MIDWEST REGIONS...INCLUDING MCV NOW EVIDENT IN COMPOSITE-
   REFLECTIVITY ANIMATIONS OVER ERN NEB.  OPERATIONAL RAP MODEL HAS
   BEEN REASONABLY WELL-TUNED TO THIS MCV FOR PAST FEW HOURS...AND THIS
   FEATURE IS PROGGED TO BE OVER WRN WI BY 00Z...EXTRAPOLATING TO NRN
   LM OVERNIGHT.  MEANWHILE...DOWNSTREAM TROUGH CURRENTLY LOCATED FROM
   LH NWD OVER ONT IS EXPECTED TO STRENGTHEN AND MOVE QUICKLY SEWD
   ACROSS MID ATLC TODAY...REACHING AXIS FROM SRN NEW ENGLAND TO
   DELMARVA BY 00Z...THEN MOVING OFFSHORE.

   AT SFC...FRONTAL ZONE WAS DRAWN AT 11Z FROM SRN NEW ENGLAND ACROSS
   CENTRAL/NRN PA THEN WNWWD OVER SRN WI...SRN MN AND NERN/N-CENTRAL
   SD...TO LOW OVER NWRN SD.  COLD FRONT EXTENDED FROM THAT LOW SWWD
   ACROSS CENTRAL/WRN WY.  WARM FRONT SHOULD MOVE NWD DIFFUSELY TODAY
   OVER MN AND ERN ND...ITS BAROCLINICITY MODULATED BY CONVECTION...
   PRECIP AND CLOUD COVER OVER PORTIONS MN/DAKOTAS.  COLD FRONT IS
   EXPECTED TO MOVE EWD ACROSS NRN PLAINS...REACHING ERN DAKOTAS...
   CENTRAL NEB AND NERN CO BY 00Z.  COLD FRONT SHOULD REACH MN
   ARROWHEAD...WRN IA...SERN NEB AND NERN KS BY 12Z.  MEANWHILE...WEAK
   COLD FRONT AND SFC TROUGH PRECEDING MID/UPPER-LEVEL SHORTWAVE TROUGH
   SHOULD CROSS NERN STATES THROUGH PERIOD...OVERTAKING PRE-EXISTING
   BAROCLINIC ZONE AND SFC TROUGH.

   ...UPPER MIDWEST...
   SEVERAL ONGOING COMPLEXES OF TSTMS HAVE COMPLICATED THIS FCST AND
   RENDERED OUTLOOK QUITE CONDITIONAL.  HOWEVER...TOO MANY MIXED
   SIGNALS STILL EXIST...WITH INSUFFICIENT EVIDENCE AGAINST LATER
   DEVELOPMENT OF SEVERE-WIND-PRODUCING MCS...TO JUSTIFY REMOVING ENH
   AREA ATTM.  SEWD MOVEMENT OF RELATIVELY CONCENTRATED AREA OF TSTMS
   WITH DAMAGING GUSTS AND ISOLATED LARGE HAIL STILL APPEARS POSSIBLE
   IN AND NEAR ENH AREA...BUT SUBSTANTIAL ADJUSTMENT MAY BE REQUIRED IN
   SUCCEEDING OUTLOOKS AS MESOSCALE CONVECTIVE/INSTABILITY TRENDS
   WARRANT.

   MAIN FACTOR ATTM IS ARC OF CONVECTION FROM ERN SD ACROSS WRN IA AND
   SERN NEB...WHICH IS EXPANSIVE EXTENSION OF OVERNIGHT ACTIVITY
   PROPAGATING ALONG ITS OWN OUTFLOW.  SFC ANALYSIS INDICATES SOME
   THETAE/DEW-POINT DEFICIT WITH THAT OUTFLOW...BUT NOT ENOUGH YET TO
   CATEGORICALLY RULE OUT CORRIDOR OF FAVORABLE MOISTURE BETWEEN IT AND
   WARM FRONT TO SUPPORT SVR CONVECTION LATER TODAY.  TSTMS NOW OVER
   CENTRAL ND MAY INTENSIFY THROUGH AFTN AS THEY ENCOUNTER
   PROGRESSIVELY GREATER LOW-LEVEL MOISTURE WITH EWD EXTENT NEAR
   NWD-MOVING WARM FRONT...WITH DEW POINTS IN PRECONVECTIVE WARM-SECTOR
   AIR MASS GENERALLY IN UPPER 60S TO UPPER 70S F.  HOWEVER...
   CONSIDERABLE CLOUD COVER IN THAT PROSPECTIVE MCS PATH WILL MUTE
   DIABATIC/DIURNAL HEATING AND...WITH SUFFICIENTLY DENSE
   CONCENTRATIONS BETWEEN NOW AND AFTN...MAY REDUCE MLCAPE
   SUBSTANTIALLY FROM WHAT HAS BEEN PROGGED.  THIS CONDITIONALITY...IN
   TURN...WILL INFLUENCE DOWNSHEAR DEVELOPMENT/PROPAGATION OF ANY
   DIURNAL TO NOCTURNAL MCS -- BOTH IN TERMS OF PATH AXIS AND BREADTH.

   ...ERN NY/NEW ENGLAND...
   WIDELY SCATTERED TSTMS SHOULD DEVELOP AND MOVE EWD TO SEWD ACROSS
   OUTLOOK AREA MIDDAY THROUGH AFTN...OFFERING SPORADIC DAMAGING WIND
   WITH ISOLATED SVR GUSTS POSSIBLE.  COMBINATION OF SFC DIABATIC
   HEATING AND DCVA/COOLING ALOFT PRECEDING SHORTWAVE TROUGH SHOULD
   DESTABILIZE TROPOSPHERIC COLUMN SUFFICIENTLY TO SUPPORT CONVECTION
   FROM LATE MORNING THROUGH AFTN.  LOW-LEVEL CONVERGENCE WILL BE SMALL
   GIVEN SUBSTANTIAL WLY COMPONENT OF NEAR-SFC WINDS...HOWEVER MLCINH
   WILL BE WEAK AS WELL.  SFC DEW POINTS UPPER 50S TO MID 60S F ARE
   FCST...DEPENDING BOTH ON LOCAL MIXING EFFECTS...ELEVATION AND GEN
   INCREASE IN MOISTURE WITH SWD EXTENT.  THIS WILL SUPPORT PEAK
   PRECONVECTIVE MLCAPE IN 500-1000 J/KG RANGE...ATOP REASONABLY
   WELL-MIXED BOUNDARY LAYERS.  STG MID/UPPER WINDS ARE EXPECTED...
   THOUGH DEEP SHEAR WILL BE LIMITED BY UNIDIRECTIONAL NATURE OF
   DEEP-LAYER FLOW.  STRONGEST DOWNDRAFTS MAY TRANSPORT ENOUGH HIGHER
   MOMENTUM FROM ALOFT TO SFC FOR DAMAGING GUSTS..ESPECIALLY WITH SOME
   HELP FROM SUBCLOUD EVAPORATION.

   ..EDWARDS/MARSH.. 07/23/2016

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z