May 12, 2022 1630 UTC Day 1 Convective Outlook
Updated: Thu May 12 16:56:47 UTC 2022 (20220512 1630Z Day 1 shapefile | 20220512 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20220512 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MODERATE 36,622 727,922 Fargo, ND...Moorhead, MN...Aberdeen, SD...Watertown, SD...Brookings, SD...
ENHANCED 93,607 5,963,458 Omaha, NE...Minneapolis, MN...St. Paul, MN...Lincoln, NE...Sioux Falls, SD...
SLIGHT 178,138 5,111,407 Jackson, MS...Rochester, MN...Duluth, MN...Eau Claire, WI...Ames, IA...
MARGINAL 276,410 11,861,841 Kansas City, MO...New Orleans, LA...Wichita, KS...Baton Rouge, LA...Lubbock, TX...
Probabilistic Tornado Graphic
20220512 1630 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 12,294 89,701 Aberdeen, SD...Huron, SD...
10 % 30,492 536,416 Fargo, ND...Moorhead, MN...Aberdeen, SD...West Fargo, ND...Fergus Falls, MN...
5 % 40,992 1,164,018 Sioux Falls, SD...St. Cloud, MN...Watertown, SD...Willmar, MN...Brookings, SD...
2 % 96,560 5,299,675 Minneapolis, MN...St. Paul, MN...Sioux City, IA...Bloomington, MN...Plymouth, MN...
Probabilistic Damaging Wind Graphic
20220512 1630 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 76,269 1,936,597 Sioux Falls, SD...Fargo, ND...Sioux City, IA...St. Cloud, MN...Moorhead, MN...
45 % 36,589 726,067 Fargo, ND...Moorhead, MN...Aberdeen, SD...Watertown, SD...Brookings, SD...
30 % 84,338 5,924,563 Omaha, NE...Minneapolis, MN...St. Paul, MN...Lincoln, NE...Sioux Falls, SD...
15 % 129,799 4,749,969 Jackson, MS...Rochester, MN...Duluth, MN...Eau Claire, WI...Ames, IA...
5 % 258,141 11,405,758 Kansas City, MO...New Orleans, LA...Wichita, KS...Baton Rouge, LA...Lubbock, TX...
Probabilistic Large Hail Graphic
20220512 1630 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 79,219 686,928 Grand Island, NE...Kearney, NE...Aberdeen, SD...Hastings, NE...Hays, KS...
30 % 56,565 672,403 Grand Island, NE...Kearney, NE...Norfolk, NE...Aberdeen, SD...Hastings, NE...
15 % 212,953 9,191,896 Omaha, NE...Minneapolis, MN...St. Paul, MN...Lincoln, NE...Sioux Falls, SD...
5 % 249,557 8,457,548 Kansas City, MO...Wichita, KS...Lubbock, TX...Des Moines, IA...Overland Park, KS...
   SPC AC 121656

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1156 AM CDT Thu May 12 2022

   Valid 121630Z - 131200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF SOUTH DAKOTA...SOUTHEAST NORTH DAKOTA...AND WESTERN MINNESOTA...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE LOWER
   MISSISSIPPI VALLEY...

   ...SUMMARY...
   Severe thunderstorm gusts (some near 75 mph), large hail and a few
   tornadoes are expected over parts of the eastern Dakotas, eastern
   Nebraska, western Iowa, and central/southern Minnesota this
   afternoon into tonight. Other severe storms are expected across the
   southern Plains and Lower Mississippi Valley.

   ...Northern/central Plains and Upper Midwest...
   Have made spatial (westward) adjustments to the categorical Moderate
   Risk along with some increased potential for initial severe-discrete
   storms, which includes the potential for a strong tornado, across
   South Dakota. In general, scattered to numerous thunderstorms are
   expected to develop in an arc near the surface low and cold front by
   mid/late afternoon, from central/eastern South Dakota southward
   across central/eastern Nebraska and into at least northern Kansas. A
   brief interval, early in the convective cycle, may support discrete
   to semi-discrete supercells before the convection becomes
   quasi-linear. The most common severe type should evolve quickly to
   thunderstorm gusts through early evening -- some of which may be
   significant (65+ kt) strength, especially from parts of eastern
   South Dakota and southeast North Dakota into western Minnesota.

   The warm sector is forecast to destabilize throughout the day, with
   a combination of at least weak large-scale ascent (increasing
   northward), diurnal heating and related lift from below, and
   ultimately frontal convergence, eliminating a basal EML inversion
   and supporting convection initiation. Activity is expected to
   intensify quickly as it impinges on a narrow but very favorable
   prefrontal corridor where 60s to near 70 F surface dewpoints
   contribute to MLCAPE in the 3500-4500 J/kg range in and near the
   "moderate" area, decreasing gradually with southward extent as more
   low-level moisture is mixed out. Low-level and deep shear will be
   greatest near the triple point and warm front across South Dakota,
   with 300-500 m2/s2 effective SRH and 45-55-kt effective-shear
   magnitudes. A substantial component of mid/upper winds parallel to
   the axis of convective forcing indicates potential for fairly fast
   merging of early discrete and sporadically supercellular convection.
   Surges of wind from resulting LEWP/bowing segments will pose the
   greatest overall severe hazard, with line-embedded mesovortices and
   perhaps a few associated tornadoes also possible. With the warm
   sector's not being very broad, the convective event should diminish
   late this evening into early overnight hours as it outruns the most
   favorable instability.

   ...Eastern Minnesota/northern Wisconsin/northern Michigan today...
   An ongoing linear complex of storms may persist eastward today in
   vicinity of the warm front and nearby moist/unstable air mass. For
   additional details, see Mesoscale Discussion 733.

   ...Portions of Mississippi/Louisiana and western Alabama...
   Have upgraded portions of the region to a categorical Slight Risk.
   Morning upper-air data reflects moderately strong
   north-northeasterly mid/high-level winds across the region to the
   west of the low centered in the Atlantic off the coastal Southeast.
   Ample insolation/heating is occurring in conjunction with a moist
   air mass across the region. This will contribute to scattered
   thunderstorm development this afternoon with gradual clustering and
   some potential for upscale evolution into multiple
   southwestward-moving semi-organized clusters. Isolated wind damage
   is expected to the primary severe hazard.

   ..Guyer/Wendt.. 05/12/2022

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