Jun 12, 2017 1730 UTC Day 2 Convective Outlook
Updated: Mon Jun 12 17:36:28 UTC 2017 (20170612 1730Z Day 2 shapefile | 20170612 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170612 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 93,523 2,343,999 Sioux Falls, SD...Fargo, ND...Sioux City, IA...St. Cloud, MN...Moorhead, MN...
SLIGHT 151,847 7,454,887 Omaha, NE...Minneapolis, MN...St. Paul, MN...Lincoln, NE...Lubbock, TX...
MARGINAL 396,585 62,287,743 New York, NY...Chicago, IL...Detroit, MI...Milwaukee, WI...Boston, MA...
Probabilistic Graphic
20170612 1730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 77,706 1,829,954 Sioux Falls, SD...Fargo, ND...Sioux City, IA...Grand Island, NE...Moorhead, MN...
30 % 93,523 2,343,999 Sioux Falls, SD...Fargo, ND...Sioux City, IA...St. Cloud, MN...Moorhead, MN...
15 % 152,220 7,455,796 Omaha, NE...Minneapolis, MN...St. Paul, MN...Lincoln, NE...Lubbock, TX...
5 % 396,024 62,372,201 New York, NY...Chicago, IL...Detroit, MI...Milwaukee, WI...Boston, MA...
   SPC AC 121736

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1236 PM CDT Mon Jun 12 2017

   Valid 131200Z - 141200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE
   NORTH-CENTRAL PLAINS AND UPPER MIDWEST...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
   NORTHERN/CENTRAL PLAINS AND UPPER MIDWEST...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS
   WEST/NORTHWEST TX INTO FAR WESTERN OK...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE HIGH
   PLAINS TO THE GREAT LAKES AND NORTHEAST STATES...

   ...SUMMARY...
   Severe thunderstorms are expected especially Tuesday afternoon into
   Tuesday night across the north-central Plains and Upper Midwest,
   with other strong to severe thunderstorms possible across the
   southern High Plains and Northeast States.

   ...Dakotas/Nebraska to Upper Midwest...
   An upper-level trough, which will be centered over the north-central
   Rockies and adjacent High Plains early Tuesday morning, will
   continue to take on an increasingly negative upper tilt as it
   spreads east-northeastward toward the Dakotas and Upper Midwest
   through Tuesday night. A moist air mass will exist along and east of
   an eastward-moving cold front, and to the south of a
   northward-shifting warm front, which could be augmented by the
   remnants of an overnight/early Tuesday MCS from the eastern Dakotas
   into MN. Relatively rich moisture with plentiful mid/upper 60s F
   surface dewpoints beneath very steep mid-level lapse rates will
   support strong destabilization (3000+ J per kg MLCAPE) by peak
   heating, with initial development by Tuesday mid/late afternoon
   focused near the surface low/front across the eastern Dakotas into
   east-central NE.

   While the strongest winds aloft will tend to lag the front somewhat,
   backing and strengthening mid/high-level southwesterly winds atop
   the frontal zone will nonetheless yield 40+ kt of effective shear,
   which will be more than adequate for initial supercells capable of
   large hail and a few tornadoes. While storms across far eastern ND
   into northern MN will become more elevated as they spread
   northeastward Tuesday night, an organized cluster of
   near-surface-based storms could evolve and persist from eastern
   NE/southeast SD into southern MN Tuesday evening. Accordingly, at
   least some continued potential for damaging winds and severe hail
   will persist eastward into the overnight, possibly as far east as
   west/northwest portions of WI.

   ...Northeast states/southern New England...
   A weak low-amplitude disturbance or two (possibly convectively
   related) will approach the region Tuesday while an upper trough
   otherwise amplifies north of the region toward the Canadian
   Maritimes. Modestly increasing deep-layer shear and a relatively
   moist/unstable air mass near and just ahead of the
   southeast-advancing front could support some strong to severe
   thunderstorms. Localized wind damage and possibly some severe hail
   could occur Tuesday afternoon into evening in association with the
   stronger updrafts/downdrafts across the region.

   ...West/northwest TX into far western OK...
   The influence of weak height falls, associated with the
   central/northern High Plains-centered upper trough, should be
   relatively well timed with peak heating Tuesday afternoon. As
   compared to today (Monday), it seems likely that there will be a
   somewhat greater probability and coverage for some strong to severe
   thunderstorms Tuesday late afternoon into evening, initially near
   the dryline. Moderate buoyancy in the presence of as much as 35-40
   kt of effective shear could yield a few high-based supercells
   capable of large hail, with severe-caliber wind gusts also a concern
   as storms progress eastward.

   ..Guyer.. 06/12/2017

   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z