Jun 11, 2016 0600 UTC Day 1 Convective Outlook
Updated: Sat Jun 11 05:53:50 UTC 2016 (20160611 1200Z Day 1 shapefile | 20160611 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160611 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 50,001 106,242 Miles City, MT...Glendive, MT...Sidney, MT...
SLIGHT 174,045 52,964,152 New York, NY...Chicago, IL...Philadelphia, PA...Newark, NJ...Jersey City, NJ...
MARGINAL 343,209 40,119,878 Detroit, MI...Milwaukee, WI...Boston, MA...Cleveland, OH...Pittsburgh, PA...
Probabilistic Tornado Graphic
20160611 1200 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
5 % 48,364 82,937 Miles City, MT...Glendive, MT...Sidney, MT...
2 % 125,594 34,335,351 New York, NY...Newark, NJ...Jersey City, NJ...Yonkers, NY...Providence, RI...
Probabilistic Damaging Wind Graphic
20160611 1200 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 % 34,038 81,647 Glendive, MT...Sidney, MT...
15 % 170,172 52,797,074 New York, NY...Chicago, IL...Philadelphia, PA...Newark, NJ...Jersey City, NJ...
5 % 330,495 39,944,987 Detroit, MI...Milwaukee, WI...Boston, MA...Cleveland, OH...Pittsburgh, PA...
Probabilistic Large Hail Graphic
20160611 1200 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
SIG SEVERE 45,279 102,165 Williston, ND...Miles City, MT...Glendive, MT...Sidney, MT...
30 % 49,959 106,158 Miles City, MT...Glendive, MT...Sidney, MT...
15 % 174,070 52,970,697 New York, NY...Chicago, IL...Philadelphia, PA...Newark, NJ...Jersey City, NJ...
5 % 269,596 37,509,845 Detroit, MI...Milwaukee, WI...Boston, MA...Cleveland, OH...Pittsburgh, PA...
   SPC AC 110553

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1253 AM CDT SAT JUN 11 2016

   VALID 111200Z - 121200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS ACROSS PORTIONS OF ERN MT/WRN
   ND...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF ERN MT...THE
   DAKOTAS...NWRN MN...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CNTRL IA TO
   NWRN INDIANA...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF SRN NEW
   ENGLAND TO THE UPPER OHIO VALLEY AND EWD TO THE ATLANTIC COAST...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM PORTIONS OF THE NRN GREAT
   PLAINS AND NWRN MN SWWD TO THE CNTRL GREAT BASIN...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM PORTIONS OF SRN NEW
   ENGLAND TO NRN PARTS OF THE MID-ATLANTIC WWD TO IA...

   ...SUMMARY...
   SCATTERED SEVERE THUNDERSTORMS WITH DAMAGING WINDS...POTENTIALLY
   VERY LARGE HAIL...AND PERHAPS ONE OR TWO TORNADOES ARE FORECAST TO
   AFFECT PORTIONS OF EASTERN MONTANA AND WESTERN NORTH DAKOTA THIS
   AFTERNOON THROUGH TONIGHT. ISOLATED TO WIDELY SCATTERED SEVERE
   THUNDERSTORMS ARE ANTICIPATED FROM PORTIONS OF NEW ENGLAND TO THE
   MID-ATLANTIC WESTWARD TO IOWA.

   ...SYNOPSIS...
   A MID-LEVEL CYCLONE WILL TRACK NNEWD FROM PORTIONS OF WA TO
   ALBERTA...WHILE A RIDGE AMPLIFIES FROM PARTS OF THE GREAT PLAINS NWD
   OVER THE CANADIAN PRAIRIES. A SHORTWAVE TROUGH OFF THE CA COAST WILL
   APPROACH THE PACIFIC COAST...WHILE A LONG FETCH OF SSWLY FLOW E OF
   THE CYCLONE AND SHORTWAVE TROUGH ENCOURAGES THE NNEWD PROGRESSION OF
   A CONVECTIVELY ENHANCED VORT MAX PRESENTLY AFFECTING THE LOWER CO
   RIVER VALLEY. FARTHER TO THE E...A LOW-AMPLITUDE DISTURBANCE WILL
   QUICKLY PROGRESS ACROSS PARTS OF THE ERN GREAT LAKES REGION AND MOVE
   OFF THE ATLANTIC COAST...WHILE A DEEPER UPSTREAM PERTURBATION AND
   ACCOMPANYING SPEED MAX MOVE ESEWD ACROSS PARTS OF ONTARIO AND
   QUEBEC.

   ...PORTIONS OF THE NRN GREAT PLAINS...
   THE STRONG LOW-LEVEL MASS RESPONSE RELATED TO FORCING FOR ASCENT
   PRECEDING THE AFOREMENTIONED VORT MAX AND THE GLANCING INFLUENCE OF
   THE NWRN CONUS/SWRN CANADA MIGRATORY CYCLONE WILL FAVOR SFC
   CYCLOGENESIS OVER SERN/E-CNTRL MT THROUGH THE DAY. THE STRENGTHENING
   CIRCULATION SURROUNDING THE SFC CYCLONE WILL SUPPORT AN INFLUX OF
   RELATIVELY ENHANCED LOW-LEVEL MOISTURE -- SFC DEWPOINTS IN THE UPPER
   50S TO LOWER 60S -- WITHIN A NARROW CORRIDOR EXTENDING INTO ERN MT
   FROM THE DAKOTAS. THE 00Z RIW RAOB SAMPLED A 700-MB TEMP AROUND
   16.5C -- HIGHLIGHTING THE WARM EML THAT WILL BE OVERSPREADING THE
   MOISTURE CORRIDOR. PRESENT INDICATIONS ARE THAT THE MOST PROBABLE
   CONVECTIVE SCENARIO WILL BE FOR RELATED CAPPING TO CONFINE DIURNAL
   TSTM DEVELOPMENT TO THE PROXIMITY OF MODEST MID-LEVEL HEIGHT FALLS
   OVERSPREADING RICHER LOW-LEVEL MOISTURE ACROSS CNTRL/ERN MT. THIS
   ACTIVITY WOULD THEN SPREAD NNEWD/NEWD INTO/ACROSS PARTS OF WRN ND
   THROUGH THE EVENING HOURS. HIGH-BASED CONVECTION COULD ALSO DEVELOP
   WITHIN A SOMEWHAT MORE SPATIALLY SEPARATE REGIME FROM THE DEEP
   BOUNDARY LAYER IN NERN WY/SERN MT/NWRN SD ON THE EDGE OF THE VORT
   MAX. SUCH ACTIVITY COULD EVOLVE INTO NNEWD-SPREADING MULTICELL
   CLUSTERS THROUGH THE EVENING HOURS.

   GIVEN THE STEEP LAPSE RATES SAMPLED UPSTREAM -- E.G. AROUND 8.5-9.0
   C/KM IN THE H7-H5 LAYER PER RIW AND SLC 00Z RAOBS -- MLCAPE AROUND
   2000-3000 J/KG WILL LIKELY EXIST WITHIN THE MOISTURE CORRIDOR. THIS
   WILL OFFER THE POTENTIAL FOR ROBUST UPWARD CONVECTIVE ACCELERATIONS
   IN THE MODERATELY TO STRONGLY SHEARED ENVIRONMENT. SUPERCELL
   STRUCTURES AND BOWING SEGMENTS WILL LIKELY SUPPORT SCATTERED SVR
   HAIL/WIND...AND THERE WILL EXIST THE POTENTIAL FOR SIGNIFICANTLY
   SEVERE HAIL PARTICULARLY WITH ANY SUSTAINED SUPERCELL STRUCTURES. A
   RISK FOR ONE OR TWO TORNADOES WILL EXIST WITH ANY SUPERCELLS
   ANCHORED TO THE MOISTURE CORRIDOR GIVEN LONG/LOOPING HODOGRAPHS AND
   LARGE EFFECTIVE SRH RELATED TO THE TO THE LOW-LEVEL MASS RESPONSE
   DURING THE LATE AFTERNOON AND EVENING. HOWEVER...GIVEN THE NARROW
   WIDTH OF THE MOISTURE CORRIDOR...GIVEN THE INCREASING LARGE-SCALE
   ASCENT FAVORING GREATER CONVECTIVE COVERAGE/INTERACTING CONVECTIVE
   ELEMENTS...AND GIVEN SOME POTENTIAL FOR INITIALLY HIGH-BASED
   CONVECTION TO DEVELOP FROM THE DEEP BOUNDARY LAYER ON THE EDGE OF
   THE MOISTURE CORRIDOR TO QUICKLY BECOME OUTFLOW-DOMINANT...THE
   TORNADO RISK IS HIGHLY CONDITIONAL.

   ALL OF THE AFOREMENTIONED ACTIVITY WILL GRADUALLY SHIFT EWD INTO THE
   OVERNIGHT HOURS...WITH A WEAKENING TREND AS NOCTURNAL COOLING OF THE
   BOUNDARY LAYER OCCURS. HOWEVER...STRENGTHENING LOW-LEVEL WARM
   ADVECTION ASSOCIATED WITH 850-MB SLYS INCREASING TO 45 KT SHOULD
   FOSTER A TENDENCY FOR ONE OR MORE LOOSELY ORGANIZED CONVECTIVE
   CLUSTERS TO BE MAINTAINED ACROSS PARTS OF NRN ND AND INTO NWRN MN
   WITH ISOLATED TO WIDELY SCATTERED SVR HAIL POSSIBLE.

   ...PORTIONS OF NRN UT TO CNTRL WY...
   WITH H5 SSWLY FLOW AROUND 35-40 KT TRAILING TO THE SW OF THE VORT
   MAX...SUFFICIENT MID-LEVEL MOISTURE AND BUOYANCY WILL BE PRESENT FOR
   SEMI-ORGANIZED/HIGH-BASED CONVECTION TO PRODUCE LOCALLY/MARGINALLY
   SVR WINDS.

   ...PORTIONS OF NEW ENGLAND AND THE MID-ATLANTIC WWD TO IA...
   SHOWERS AND ISOLATED TSTMS WILL LIKELY BE CROSSING PORTIONS OF NY
   AND VICINITY DURING THE MORNING IN ASSOCIATION WITH THE
   LOW-AMPLITUDE DISTURBANCE. ASCENT ACCOMPANYING THIS FEATURE WILL
   LIKELY BE -- AT LEAST INITIALLY -- DISPLACED TO THE E/NE OF RICHER
   BOUNDARY-LAYER MOISTURE/STRONGER INSTABILITY...WITH LITTLE IN THE
   WAY OF A SVR RISK ANTICIPATED DURING THE MORNING. BY
   MID-AFTERNOON...SOME INTENSIFICATION OF CONVECTION MAY OCCUR AS IT
   SPREADS ACROSS PARTS OF SRN NY AND SRN NEW ENGLAND AND INTERCEPTS A
   FEED OF MOISTURE FROM THE W YIELDING DESTABILIZATION. ADDITIONAL
   CONVECTIVE DEVELOPMENT IS ALSO ANTICIPATED DURING THE AFTERNOON
   ALONG AN AXIS OF WEAK CONVERGENCE/DIFFUSE FRONT TRAILING WWD INTO
   PARTS OF IA. ISOLATED TO WIDELY SCATTERED SVR WIND/HAIL MAY
   ACCOMPANY THIS ACTIVITY INTO EARLY EVENING. THE SEPARATE SLGT AREAS
   ACCOUNT FOR SOMEWHAT GREATER ASCENT/LOW-LEVEL CONVERGENCE AND
   STRONGER DEEP SHEAR RELATED TO THE LOW-AMPLITUDE IMPULSE ACROSS THE
   ERN AREA...AND GREATER BUOYANCY -- E.G. MLCAPE AROUND 1500-2500 J/KG
   -- ACROSS THE WRN AREA. HOWEVER...MUCH OF THE REGION WILL RESIDE
   BETWEEN ZONES OF STRONGER ASCENT ACCOMPANYING THE LOW-AMPLITUDE
   DISTURBANCE AND DEEPER UPSTREAM PERTURBATION -- WITH SOMEWHAT
   HOSTILE THERMODYNAMIC CONDITIONS ALOFT MITIGATING THE OVERALL SVR
   RISK IN THE INTERVENING AREA.

   ...PORTIONS OF THE SRN HIGH PLAINS...
   CLUSTERS OF STRONG TSTMS WILL LIKELY FORM OVER THE SRN ROCKIES AND
   THEN DRIFT ACROSS THE ADJACENT HIGH PLAINS WHERE ANTECEDENT DEEP
   MIXING WILL SUPPORT A FEW STRONG DOWNDRAFTS. WEAK DEEP SHEAR WILL
   MITIGATE CONVECTIVE ORGANIZATION...PRECLUDING THE INCLUSION OF SVR
   PROBABILITIES.

   ..COHEN/GLEASON.. 06/11/2016

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z