Jun 9, 2016 0600 UTC Day 1 Convective Outlook
Updated: Thu Jun 9 05:50:48 UTC 2016 (20160609 1200Z Day 1 shapefile | 20160609 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160609 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 59,878 356,329 Billings, MT...Minot, ND...Williston, ND...Miles City, MT...Laurel, MT...
MARGINAL 208,057 14,157,033 Chicago, IL...Milwaukee, WI...Madison, WI...Lubbock, TX...Amarillo, TX...
Probabilistic Tornado Graphic
20160609 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
2 % 59,138 350,989 Billings, MT...Minot, ND...Williston, ND...Miles City, MT...Laurel, MT...
Probabilistic Damaging Wind Graphic
20160609 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
15 % 60,219 356,713 Billings, MT...Minot, ND...Williston, ND...Miles City, MT...Laurel, MT...
5 % 209,606 14,374,959 Chicago, IL...Milwaukee, WI...Madison, WI...Lubbock, TX...Amarillo, TX...
Probabilistic Large Hail Graphic
20160609 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
15 % 60,465 356,239 Billings, MT...Minot, ND...Williston, ND...Miles City, MT...Laurel, MT...
5 % 209,372 14,534,679 Chicago, IL...Milwaukee, WI...Madison, WI...Lubbock, TX...Amarillo, TX...
   SPC AC 090550

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1250 AM CDT THU JUN 09 2016

   VALID 091200Z - 101200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING
   ACROSS PARTS OF NORTHEASTERN MONTANA INTO NORTHERN NORTH DAKOTA...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF CENTRAL THROUGH
   SOUTHEASTERN MONTANA...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS SURROUNDING AREAS OF THE
   NORTHERN ROCKIES AND NORTHERN PLAINS...

   ...THERE IS A MRGL RISK OF SVR TSTMS LATE THIS AFTERNOON AND EVENING
   ACROSS PARTS OF THE SOUTHERN HIGH PLAINS...

   ...THERE IS A MRGL RISK OF SVR TSTMS LATE THIS AFTERNOON AND EVENING
   ACROSS PARTS OF THE UPPER MIDWEST...

   ...SUMMARY...
   SCATTERED SEVERE STORMS ARE EXPECTED TODAY ACROSS PARTS OF THE
   NORTHERN ROCKIES INTO THE NORTHERN PLAINS.  ADDITIONAL STRONG TO
   SEVERE STORMS ARE POSSIBLE ACROSS SOUTHERN PORTIONS OF THE HIGH
   PLAINS...AS WELL AS ACROSS PARTS OF THE UPPER MIDWEST.

   ...SYNOPSIS...
   THE STRONGER MID-LATITUDE WESTERLIES ARE GENERALLY CONFINED TO THE
   NORTHERN TIER OF THE U.S. AND SOUTHERN CANADA.  WITHIN THIS
   REGIME...A SHORT WAVE IMPULSE HAS ADVANCED INLAND ACROSS THE PACIFIC
   NORTHWEST...AND IS CURRENTLY PROGRESSING NORTHEASTWARD INTO/THROUGH
   SOUTHEASTERN BRITISH COLUMBIA...ALBERTA AND PORTIONS OF THE NORTHERN
   U.S. INTERMOUNTAIN REGION.  DURING THE DAY TODAY...STRONGER
   MID-LEVEL HEIGHT FALLS ASSOCIATED WITH THIS FEATURE ARE FORECAST TO
   SHIFT ACROSS ALBERTA INTO MANITOBA.  SUBTLE MID-LEVEL HEIGHT FALLS
   MAY GRADUALLY SPREAD EASTWARD ACROSS PARTS OF IDAHO AND
   WESTERN/CENTRAL MONTANA.  HOWEVER...MODELS GENERALLY INDICATE THAT
   LARGER-SCALE UPPER RIDGING...NOW PRESENT ACROSS THE CENTRAL
   INTERNATIONAL BORDER REGION...WILL EXPAND WESTWARD TOWARD THE
   ROCKIES...AS A DEEP CLOSED LOW AND ASSOCIATED TROUGHING DIG INTO THE
   PACIFIC NORTHWEST.  EASTWARD EXPANSION OF THIS UPPER RIDGING TOWARD
   THE UPPER GREAT LAKES REGION IS ALSO FORECAST.  THIS IS EXPECTED TO
   OCCUR AS A DOWNSTREAM CLOSED LOW ACCELERATES EAST NORTHEAST OF THE
   NORTH ATLANTIC COAST.  HOWEVER...A SHORT WAVE IMPULSE DIGGING IN THE
   WAKE OF THIS LATTER FEATURE WILL MAINTAIN CYCLONIC FLOW AND SLOW
   MID-LEVEL HEIGHT RISES ACROSS THE LOWER GREAT LAKES AND NORTHEAST. 

   IN ASSOCIATION WITH THESE DEVELOPMENTS...WARM ELEVATED MIXED LAYER
   AIR EMANATING FROM THE PLATEAU/ROCKIES REGION WILL CONTINUE TO
   ADVECT ACROSS THE NORTHERN PLAINS TOWARD THE GREAT LAKES
   REGION...WHILE ALSO EDGING EASTWARD ACROSS PARTS OF THE CENTRAL AND
   SOUTHERN PLAINS.  AT THE SAME TIME...A CONTINUED MOISTENING OF THE
   BOUNDARY LAYER IS ALSO FORECAST THROUGH MUCH OF THE PLAINS AND
   MISSISSIPPI VALLEY REGION.  EVAPOTRANSPIRATION MAY MOST PROMINENTLY
   CONTRIBUTE TO THIS ACROSS MUCH OF THE NORTHERN PLAINS INTO UPPER
   MIDWEST...BUT A MODEST SOUTHERLY LOW-LEVEL JET FROM THE CENTRAL
   PLAINS TOWARD THE UPPER MIDWEST MAY ALSO INCREASINGLY CONTRIBUTE TO
   THE NORTHWARD ADVECTION OF MOISTURE RETURN NOW UNDERWAY OFF THE GULF
   OF MEXICO INTO THE SOUTHERN PLAINS.

   ...NORTHERN ROCKIES INTO NORTHERN PLAINS...
   30-50 KT SOUTWESTERLY 500 MB FLOW...NEAR AN UPPER JET NOSING ACROSS
   THE NORTHERN ROCKIES INTO SASKATCHWAN...LIKELY WILL CONTRIBUTE TO
   SUFFICIENT SHEAR FOR ORGANIZED SEVERE STORM DEVELOPMENT TODAY. 
   SUBSTANTIVE MID-LEVEL FORCING FOR ASCENT AHEAD OF AN EASTWARD
   ADVANCING COLD FRONT ASSOCIATED WITH THE SHORT WAVE TROUGH MAY
   LARGELY BE FOCUSED NORTH OF THE INTERNATIONAL BORDER...BUT MAY
   IMPACT AREAS AS FAR SOUTH AS NORTHEASTERN MONTANA INTO NORTHERN
   NORTH DAKOTA BY LATE THIS AFTERNOON.  IF IT DOES...GUIDANCE SUGGESTS
   SUFFICIENTLY LARGE CAPE...IN THE PRESENCE OF STEEP LOWER/MID
   TROPOSPHERIC LAPSE RATES...TO SUPPORT A RISK FOR SUPERCELLS...BEFORE
   CONVECTION PERHAPS EVOLVES INTO AN ORGANIZING EASTWARD PROPAGATING
   CONVECTIVE SYSTEM NEAR THE INTERNATIONAL BORDER THIS EVENING.

   OTHERWISE...THUNDERSTORM DEVELOPMENT SEEMS MOST CERTAIN IN THE MOIST
   POST-FRONTAL LOW-LEVEL UPSLOPE FLOW ACROSS THE HIGHER TERRAIN TO THE
   SOUTH/SOUTHWEST OF GREAT FALLS AND LEWISTOWN.  WITHIN THIS
   REGIME...STRONG VERTICAL SHEAR LIKELY WILL BE SUPPORTIVE OF
   SUPERCELLS ACCOMPANIED BY AT LEAST A RISK FOR LARGE HAIL AND LOCALLY
   DAMAGING WIND GUSTS WHILE DEVELOPING EASTWARD ACROSS PARTS OF
   CENTRAL...SOUTHERN AND EASTERN MONTANA THROUGH THIS EVENING.

   ...UPPER MIDWEST...
   LOWER/MID TROPOSPHERIC WARM ADVECTION EAST OF THE WARMER AND MORE
   STRONGLY CAPPING ELEVATED MIXED LAYER AIR...AND NEAR THE NOSE OF A
   BRANCH OF THE SOUTHERLY LOW-LEVEL JET EXTENDING NORTHEASTWARD FROM
   THE PLAINS...WILL PROVIDE A POTENTIAL FOCUS FOR VIGOROUS
   THUNDERSTORM DEVELOPMENT.  VERTICAL SHEAR LIKELY WILL BE STRONG
   BENEATH NORTHWEST MID-LEVEL FLOW.  HOWEVER...THE EXTENT OF BOUNDARY
   LAYER MOISTENING AND DESTABILIZATION IN CLOSE PROXIMITY TO THE
   STRONGEST ZONE OF ASCENT REMAINS UNCLEAR.  STRONG/SEVERE STORM
   DEVELOPMENT DOES NOT APPEAR ENTIRELY OUT OF THE QUESTION...WITH THE
   EVOLUTION OF ONE OR TWO SMALL CONVECTIVE CLUSTERS
   POSSIBLE...PARTICULARLY WITH NOCTURNAL LOW-LEVEL JET STRENGTHENING
   LATE THIS EVENING INTO THE OVERNIGHT HOURS.

   ...CENTRAL/SOUTHERN HIGH PLAINS...
   SOUTH OF THE MID-LATITUDE WESTERLIES...A WEAK PERTURBATION WILL
   CONTINUE TO SLOWLY ADVANCE SOUTHEAST OF THE CENTRAL/SOUTHERN ROCKIES
   TODAY.  AS IT DOES...MODELS SUGGEST THAT IT MAY WEAKEN INHIBITION
   SUFFICIENTLY TO ALLOW FOR THE DEVELOPMENT OF SCATTERED
   THUNDERSTORMS.  IN THE PRESENCE OF THERMODYNAMIC PROFILES
   CHARACTERIZED BY STEEP LAPSE RATES AND MODERATELY LARGE CAPE...SOME
   OF THIS ACTIVITY COULD BECOME CAPABLE OF PRODUCING LOCALIZED STRONG
   SURFACE GUSTS AND MARGINALLY SEVERE HAIL.  THIS COULD BE AIDED FOR A
   PERIOD THIS EVENING BY MODEST SOUTHERLY LOW-LEVEL JET STRENGTHENING.

   ..KERR/GLEASON.. 06/09/2016

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