Aug 5, 2023 1300 UTC Day 1 Convective Outlook
Updated: Sat Aug 5 12:47:24 UTC 2023 (20230805 1300Z Day 1 shapefile | 20230805 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20230805 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 79,520 2,605,451 Tulsa, OK...Wichita, KS...Broken Arrow, OK...Enid, OK...Stillwater, OK...
SLIGHT 217,513 15,718,292 Indianapolis, IN...Memphis, TN...Denver, CO...Oklahoma City, OK...Omaha, NE...
MARGINAL 272,253 19,172,225 Nashville, TN...Kansas City, MO...Louisville, KY...Birmingham, AL...Montgomery, AL...
Probabilistic Tornado Graphic
20230805 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
5 % 35,118 3,867,761 Indianapolis, IN...Sioux Falls, SD...Sioux City, IA...Champaign, IL...Bloomington, IN...
2 % 85,936 4,749,796 Omaha, NE...Louisville, KY...Lincoln, NE...Evansville, IN...Decatur, IL...
Probabilistic Damaging Wind Graphic
20230805 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 80,196 2,142,954 Tulsa, OK...Amarillo, TX...Broken Arrow, OK...Enid, OK...Stillwater, OK...
30 % 65,413 2,497,874 Tulsa, OK...Wichita, KS...Broken Arrow, OK...Enid, OK...Stillwater, OK...
15 % 177,930 9,401,712 Memphis, TN...Oklahoma City, OK...Omaha, NE...Lincoln, NE...Amarillo, TX...
5 % 308,527 24,294,365 Indianapolis, IN...Denver, CO...Nashville, TN...Kansas City, MO...Colorado Springs, CO...
Probabilistic Large Hail Graphic
20230805 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 63,701 3,459,051 Denver, CO...Colorado Springs, CO...Aurora, CO...Lakewood, CO...Thornton, CO...
30 % 22,050 143,625 Guymon, OK...Lamar, CO...
15 % 156,855 7,527,050 Denver, CO...Omaha, NE...Colorado Springs, CO...Wichita, KS...Aurora, CO...
5 % 177,684 11,958,240 Memphis, TN...Oklahoma City, OK...Kansas City, MO...Tulsa, OK...Little Rock, AR...
   SPC AC 051247

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0747 AM CDT Sat Aug 05 2023

   Valid 051300Z - 061200Z



   The most concentrated area of severe thunderstorms with potential
   for destructive wind and hail is expected across parts of the
   south-central Great Plains from mid-afternoon through tonight.
   Potential for a few tornadoes will exist separately over the
   Mid-Missouri and Wabash Valleys during the late afternoon to early

   ...South-central Great Plains to the Mid-South...
   A small MCS is ongoing along the southeast KS/northeast OK border
   area and may persist east-southeast across portions of the Ozark
   Plateau through midday. How it evolves into the afternoon across the
   Mid-South is uncertain given variation among CAM guidance that has
   adequately simulated the MCS so far (namely the 06/09Z RRFS and 00Z
   NSSL-WRF/10Z HRRR), as it progresses away from the more strongly
   sheared environment to its west-northwest but impinges on larger
   buoyancy over MO/AR. Have expanded the cat 2-SLGT risk some to
   account for potentially greater east-southeast progression and/or
   redevelopment later this afternoon with the remnant MCV. 

   In the wake of this morning MCS, convective outflow arcs across
   central OK through the central TX Panhandle. Hot and deeply mixed
   thermodynamic profiles will develop to the south of this boundary
   amid full insolation, while capping to the north inhibits
   thunderstorm development until peak heating. Initial cells should
   develop off the Raton Mesa and Palmer Divide towards mid-afternoon
   within a low-level upslope flow regime and the left exit region of
   an intense upper jet from CA to CO. Potential will exist for
   regenerative supercells spreading east-southeast off the higher
   terrain. A few of these may become long-lived and capable of
   producing baseball to softball-sized hail centered on the southeast
   CO vicinity given highly elongated mid to upper hodographs and large
   buoyancy amid very steep mid-level lapse rates. 

   A strengthening low-level jet over west TX during the evening will
   favor increasing convective development downstream and yield
   multiple clusters spreading across western and southern KS, the
   Panhandles, and western to northern OK during the evening. Severe
   wind gusts will become more prolific as this occurs, which should
   include potential for sporadic gusts from 70-90 mph. CAM guidance
   struggles to indicate a more prominent MCS evolving out of the
   clusters that should form, lowering confidence on where the most
   concentrated swath of significant severe wind gusts is likely to
   evolve tonight. But a broad region of at least scattered severe wind
   potential supports maintaining a cat 3-ENH risk. 

   ...Mid-MO Valley vicinity...
   A mid-level low over central SD will drift east with stronger
   destabilization confined downstream of it from southeast SD to
   eastern NE and far western IA. Early afternoon convective
   development will initially be most pronounced across southeast SD
   and likely arc southward into at least northeast NE before spreading
   into northwest IA later. Weaknesses in the mid-level wind profile
   may yield a linear cluster type mode, but some enlargement to the
   low-level hodograph, especially in the SD/NE/IA border area, should
   foster low-level updraft rotation capable of producing a couple
   tornadoes. Otherwise, slow-moving linear clusters will yield a
   threat for isolated severe hail and wind persisting through the

   ...IL/IN vicinity...
   An MCV over central IL will drift east into IN through tonight.
   Enhanced wind fields attendant to this MCV were sampled by the 12Z
   ILX sounding and will yield a spatially confined corridor of
   favorable low-level SRH overlapping the northeast extent of the
   surface-based instability plume in southern parts of IL/IN. This
   should support a few supercells developing during the mid afternoon
   to early evening, centered on the Wabash Valley into portions of
   central/southern IN. Any supercell will be capable of a tornado, and
   localized severe wind gusts will be the primary threat with
   convection that arcs southwestward towards larger buoyancy across
   the Lower OH Valley.

   ..Grams/Broyles.. 08/05/2023