May 30, 2022 1300 UTC Day 1 Convective Outlook
Updated: Mon May 30 12:50:31 UTC 2022 (20220530 1300Z Day 1 shapefile | 20220530 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20220530 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MODERATE 33,780 670,945 Watertown, SD...Willmar, MN...Brookings, SD...Fergus Falls, MN...Brainerd, MN...
ENHANCED 93,055 6,274,199 Minneapolis, MN...St. Paul, MN...Sioux Falls, SD...Topeka, KS...Fargo, ND...
SLIGHT 104,283 4,204,043 Omaha, NE...Wichita, KS...Des Moines, IA...Rochester, MN...Duluth, MN...
MARGINAL 89,046 3,547,846 Kansas City, MO...Lincoln, NE...Overland Park, KS...Kansas City, KS...Cedar Rapids, IA...
Probabilistic Tornado Graphic
20220530 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
SIG SEVERE 75,503 1,818,205 Sioux Falls, SD...Fargo, ND...St. Cloud, MN...Moorhead, MN...Watertown, SD...
15 % 26,161 555,100 Watertown, SD...Willmar, MN...Brookings, SD...Fergus Falls, MN...Brainerd, MN...
10 % 78,256 2,529,910 Sioux Falls, SD...Topeka, KS...Fargo, ND...St. Cloud, MN...Ames, IA...
5 % 82,401 6,051,997 Minneapolis, MN...Wichita, KS...St. Paul, MN...Des Moines, IA...Rochester, MN...
2 % 82,082 4,162,342 Kansas City, MO...Omaha, NE...Overland Park, KS...Kansas City, KS...Olathe, KS...
Probabilistic Damaging Wind Graphic
20220530 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
SIG SEVERE 99,459 5,577,333 Minneapolis, MN...St. Paul, MN...Sioux Falls, SD...Fargo, ND...Bloomington, MN...
45 % 33,820 671,748 Watertown, SD...Willmar, MN...Brookings, SD...Fergus Falls, MN...Brainerd, MN...
30 % 59,427 4,766,999 Minneapolis, MN...St. Paul, MN...Sioux Falls, SD...Fargo, ND...Bloomington, MN...
15 % 138,348 5,746,186 Omaha, NE...Wichita, KS...Des Moines, IA...Topeka, KS...Rochester, MN...
5 % 88,652 3,516,875 Kansas City, MO...Lincoln, NE...Overland Park, KS...Kansas City, KS...Cedar Rapids, IA...
Probabilistic Large Hail Graphic
20220530 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
SIG SEVERE 117,394 6,207,004 Wichita, KS...Des Moines, IA...Sioux Falls, SD...Topeka, KS...Fargo, ND...
30 % 91,696 6,126,681 Minneapolis, MN...St. Paul, MN...Sioux Falls, SD...Topeka, KS...Bloomington, MN...
15 % 139,556 5,027,834 Omaha, NE...Wichita, KS...Des Moines, IA...Rochester, MN...Fargo, ND...
5 % 88,667 3,530,616 Kansas City, MO...Lincoln, NE...Overland Park, KS...Kansas City, KS...Cedar Rapids, IA...
   SPC AC 301250

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0750 AM CDT Mon May 30 2022

   Valid 301300Z - 311200Z


   Numerous severe thunderstorms are forecast across parts of the
   Northern Plains and Upper Mississippi Valley, with more scattered to
   isolated activity southward into the central Plains today into
   tonight. Large to giant hail, 60-80 mph gusts, and tornadoes are
   probable, including the possibility for a couple strong/long-tracked

   A large field of mid/upper-level cyclonic flow covers most of the
   western/central CONUS, anchored by a broad, complex cyclone covering
   much of the northern/central Rockies and Intermountain region. 
   Primary vorticity maxima are evident in moisture-channel imagery
   over ID and central/eastern CO.  The latter will eject northeastward
   today, become a compact, closed cyclone in its own right, and deepen
   considerably, with the 500-mb low reaching east-central SD by 00Z. 
   Meanwhile the western vorticity lobe will remain weaker and meander
   around southern ID/northern NV through the period.

   The 11Z surface analysis showed a low over extreme southeastern ND,
   with cold front across eastern SD, south-central NE, northwestern
   KS, and central CO.  Another low was noted along the dryline between
   GCK-HYS.  The southern low will move northward, merge onto the
   front, and intensify through the day as its mid/upper counterpart
   approaches, until the lows become stacked over east-central SD
   around 00Z.  By then the surface low should be occluded, with a
   triple point over southwestern MN and cold front arching across
   western IA, southeastern NE and northern/western KS.

   An outflow boundary from prior MCS activity was drawn across
   southwestern MN, northwestern IA and northeastern NE.  This boundary
   may maintain its identity for a few more hours before retreating
   northward and becoming more ill-defined amidst intense
   surface-850-mb warm advection and moisture transport.  Both ongoing
   and future/intervening convective processes cast uncertainty over
   specific timing/location of these features across the northern
   Plains and Upper Midwest into the afternoon.  A dryline -- drawn
   initially across western KS, the TX Panhandle and southward into the
   Big Bend region -- will shift eastward to central KS, western OK and
   west-central TX this afternoon, before being overtaken from
   north-south by the cold front over KS tonight.

   ...Northern Plains/Upper Midwest...
   Scattered to numerous thunderstorms, offering tornadoes (some
   potentially strong/EF2+), severe wind and occasional large/damaging
   hail, will be possible into this evening.  The greatest coverage
   should be in and near the "moderate" and "enhanced" categorical
   areas, where low-level convergence and convective coverage each
   should be greatest.  The main convective regime should develop as
   early as midday near the retreating outflow boundary across northern
   NE, southeastern SD and southwestern MN, growing upscale and
   sweeping north-northeastward through the remainder of the outlook
   area this afternoon and early evening.

   With the passage of such an intense prior-overnight/morning MCS to
   the south and east of the axis of the outlook area, and a
   well-defined outflow boundary currently entirely displaced from the
   greater severe probabilities, normally there would be great
   concern/uncertainty about airmass recovery.  To some extent there is
   -- especially with northern extent across ND/MN.  This is not a
   "normal" scenario, however, with higher-end kinematic/mass response
   to the approaching cyclone fostering very intense, deep-tropospheric
   meridional flow (the direction needed for favorable thermodynamic
   recovery) and related strong surface-850-mb warm advection.  The
   remains of the outflow boundary accordingly should disperse through
   the day, and the stable air to its north will modify and advect
   northward out of at least some, perhaps most, of the outlook area. 
   The probabilities supporting "enhanced" and "moderate" risks have
   been adjusted slightly eastward and compacted on the west side, to
   reflect the likely tight gradient between substantial and limited
   severe potential.  Still, the axis of greatest probabilities remains
   somewhat uncertain and fluid, and may need further adjustment
   through the day as mesoscale trends warrant.

   Despite the component of mean-wind and deep-shear vectors off the
   axis of strongest low-level forcing, the intense deep-layer lift may
   compel a relatively quick transition from initial supercellular
   characteristics to mixed modes, then quasi-linear with embedded
   LEWPs/bows/mesocirculations.  Forecast soundings suggest 2000-3000
   J/kg MLCAPE can develop across the corridor from northeastern NE to
   central MN before the main round of convection, along with 55-70-kt
   effective-shear magnitudes, and effective SRH in the 150-300 J/kg
   range, with long, somewhat curved hodographs.

   ...Western IA to eastern/southern KS...
   Widely scattered to isolated thunderstorms may develop late this
   afternoon into evening in a northeast/southwest corridor related to
   the front and dryline.  Though coverage may be limited by stronger
   EML-related capping, and weaker deep-layer forcing that farther
   north, the parameter space in the adjacent warm sector will be
   favorable for supercells.  The stronger MLCINH also may favor
   longer-lasting, relatively discrete modes, further supporting the
   somewhat conditional tornado and significant-hail threats.  Enough
   guidance indicates development of at least a few sustained cells in
   this regime that unconditional probabilities have been increased.

   This area will reside near the axis of the strongest 300-700-mb flow
   this afternoon and evening, enabling 55-65-kt effective-shear
   magnitudes, while low-level shear/hodographs enlarge with the LLJ
   intensification in the 00-03Z time frame.  Surface dew points
   generally in the 60s F and steep low/middle-level lapse rates will
   support a plume of 2000-3000 J/kg MLCAPE parallel to and ahead of
   the front and dryline.

   ..Edwards/Mosier.. 05/30/2022