Aug 5, 2023 1630 UTC Day 1 Convective Outlook
Updated: Sat Aug 5 16:27:18 UTC 2023 (20230805 1630Z Day 1 shapefile | 20230805 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20230805 1630 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 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
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 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 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 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 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 051627

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1127 AM CDT Sat Aug 05 2023

   Valid 051630Z - 061200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN
   COLORADO INTO SOUTHERN KANSAS AND NORTHERN OKLAHOMA...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN A SEPARATE AREA
   FROM EASTERN ILLINOIS INTO CENTRAL AND SOUTHERN PARTS OF INDIANA...

   ...SUMMARY...
   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
   evening.

   ...Synopsis...
   Water-vapor imagery this morning shows a rather complex upper-air
   pattern with several important features that will influence the
   severe threat this afternoon into tonight.  An MCV located over the
   southeast KS/northeast OK vicinity will continue to move east across
   the Ozarks during the day.  Another MCV over IL will gradually shift
   east into IN by this evening.  A mid-level low will move little over
   SD during the period, while a belt of stronger mid- to upper-level
   flow associated with an upper jet noses into the central High
   Plains.  In the low levels, extensive outflow is evident over much
   of the northern half of OK into KS in wake of earlier morning
   thunderstorm activity near the OK/KS border.  Easterly low-level
   flow will aid in maintaining moist conditions into eastern CO
   southward to the Raton Mesa.  A narrow moist plume will protrude
   northward from eastern NE/western IA into southeast SD ahead of a
   gradually eastward-moving cool front.  Low-level confluence will aid
   in focusing thunderstorm development over the lower Wabash Valley
   beginning early this afternoon through early evening.  

   ...Eastern CO/northeast NM into the TX Panhandle and KS/OK...
   Not much change from previous forecast thinking.  Convective outflow
   late this morning arcs westward across central OK through the
   central TX Panhandle.  Near and north of the outflow, late morning
   thunderstorms over OK may continue to linger into the mid afternoon
   across the northern half of OK and pose an isolated risk for severe
   gusts.  The initial thunderstorm development and more appreciable
   severe risk will probably focus near the Raton Mesa and Palmer
   Divide towards mid-afternoon.  Moist upslope flow beneath the left
   exit region of an upper jet overspreading the central High Plains
   will facilitate a favorable setup for supercells.  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 with multiple severe
   thunderstorm clusters spreading across western and southern KS, the
   Panhandles, and western to northern OK.  Severe
   wind gusts will become more prolific as this occurs, which should
   include potential for sporadic gusts from 70-85 mph.  

   ...Ozarks/Mid South...
   Ongoing thunderstorm cluster late this morning will continue to move
   east into a destabilizing and very unstable airmass across northern
   AR.  Strong heating via mostly clear skies will result in
   temperatures warming into the 90s with mid to upper 70s dewpoints. 
   Forecast soundings show a moderate mid-level flow enhancement via
   the approaching disturbance and MLCAPE 3000-4500 J/kg.  Although
   uncertainty is high regarding details, it is possible some
   rejuvenation to the thunderstorm activity occurs on the periphery of
   the deeper cores going forward into the early-mid afternoon.  If
   this occurs, widely scattered strong to severe gusts are possible
   into the early evening.  
     
   ...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
   evening.

   ...IL/IN vicinity...
   An MCV over central IL will drift east into IN through tonight.
   Continued destabilization despite appreciable cloud cover will
   become increasingly conducive for scattered storms to develop by
   early to mid afternoon.  Forecast soundings show 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.  A few supercells will probably evolve as storms
   mature through the late afternoon/early evening and move east into
   south-central IN.  Any vigorous updraft/supercell will be capable of
   at least an isolated, short-term risk for a tornado given the wind
   profile/moist low levels.

   ..Smith/Squitieri.. 08/05/2023

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