Jun 9, 2024 2000 UTC Day 1 Convective Outlook
Updated: Sun Jun 9 19:58:44 UTC 2024 (20240609 2000Z Day 1 shapefile | 20240609 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20240609 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 46,307 3,533,321 Memphis, TN...Little Rock, AR...North Little Rock, AR...Jonesboro, AR...Conway, AR...
MARGINAL 577,742 35,244,483 Charlotte, NC...Denver, CO...Atlanta, GA...Colorado Springs, CO...Aurora, CO...
Probabilistic Tornado Graphic
20240609 2000 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
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20240609 2000 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
15 % 46,326 3,533,521 Memphis, TN...Little Rock, AR...North Little Rock, AR...Jonesboro, AR...Conway, AR...
5 % 577,601 35,237,088 Charlotte, NC...Denver, CO...Atlanta, GA...Colorado Springs, CO...Aurora, CO...
Probabilistic Large Hail Graphic
20240609 2000 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
15 % 46,385 3,532,330 Memphis, TN...Little Rock, AR...North Little Rock, AR...Jonesboro, AR...Conway, AR...
5 % 445,170 33,475,796 Charlotte, NC...Denver, CO...Atlanta, GA...Colorado Springs, CO...Aurora, CO...
   SPC AC 091958

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0258 PM CDT Sun Jun 09 2024

   Valid 092000Z - 101200Z


   A broad area of isolated severe hail and damaging wind potential
   exists today from parts of the Northwest into the High Plains,
   southern Plains, and lower Mississippi Valley/Southeast. A
   relatively greater severe threat may exist this afternoon and early
   evening across parts of Arkansas, southwest Tennessee, northern
   Mississippi, and northern/central Alabama.

   ...20z Update...

   No changes are need to the D1 Outlook. Thunderstorm activity has
   begun across much of the Marginal Risk area extending from the
   Northwest into the High/Southern Plains, and into the lower
   Mississippi Valley. Activity is expected to remain widely scattered
   with potential for a few instances of damaging winds and hail. 

   The more concentrated severe risk area remains evident across the
   lower Mississippi Valley into the Southeast. Visible satellite shows
   initiation ongoing across northwestern Arkansas near a diffuse
   surface boundary. This activity will spread east and southeastward
   through the afternoon. Ahead of this activity, daytime heating has
   allowed a broad region of 2000-3000 J/kg of MLCAPE extending from
   Arkansas into northern Mississippi and Alabama. This will support
   multi-cell clusters capable of damaging wind and a few instances of
   hail. The Slight Risk covers this risk well, with no updates needed
   at this time.

   ..Thornton/Goss.. 06/09/2024

   .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun Jun 09 2024/

   ...Lower Mississippi Valley/Southeast...
   A MCV is present over southern MO/northern AR late this morning.
   Outflow from this activity has spread south of the remnant ongoing
   convection into central AR and far western TN. A very moist
   low-level airmass across the lower MS Valley will continue to
   destabilize as strong diurnal heating occurs through the afternoon.
   Moderate to strong instability will likely develop across parts of
   AR, western TN, and northern MS, with MLCAPE values potentially
   reaching around 2000-3500 J/kg. Stronger mid-level flow will tend to
   remain displaced to the north of the warm sector today across the OH
   Valley, Mid-Atlantic, and Northeast in association with an upper
   trough/low centered over eastern Canada. Still, some enhancement to
   the mid-level flow due to the MCV, with gradually strengthening
   west-northwesterly winds at mid/upper levels, should support
   sufficient deep-layer shear for thunderstorm organization. Current
   expectations are for robust thunderstorms to develop along/near the
   outflow boundary in northern/central AR this afternoon, and
   subsequently spread east-southeastward over parts of southwest TN,
   northern MS, and perhaps northern/central AL through the evening.
   Multicell clusters will be capable of producing scattered damaging
   winds around 50-70 mph. Isolated hail may also occur with any
   marginal supercell structures that can be maintained. Convection
   should gradually weaken through the evening across the Deep South as
   it encounters a less unstable airmass and increasing MLCIN.

   A separate MCV is apparent over the western Carolinas based on
   recent visible satellite imagery. As this feature moves eastward, it
   may encourage isolated thunderstorms to develop through the day
   across parts of NC/SC. While this region will be on the southern
   periphery of stronger mid-level flow, sufficient deep-layer shear
   should be present to support modest updraft organization. Isolated
   hail and strong to damaging winds may occur with the more robust
   cores that can develop. But, generally weak instability should keep
   the overall severe threat fairly isolated.

   ...Southern/Central High Plains...
   With weak east-northeasterly low-level upslope flow persisting
   today, scattered to numerous thunderstorms should develop this
   afternoon over the higher terrain of the southern/central Rockies.
   Additional convective development is anticipated across parts of the
   southern Plains in the vicinity of a convectively reinforced front
   extending from parts of west TX into southern/eastern OK. Generally
   modest flow is forecast over much of these areas, which should limit
   thunderstorm organization to some extent. Still, a moist and
   moderately unstable airmass should be in place along/south of the
   front, and in a narrow corridor across the High Plains. Where
   low-level lapse rates can become steepened though daytime
   heating/mixing of the boundary layer, isolated severe wind gusts may
   occur with pulse convection and loosely organized multicell
   clusters. Hail may also occur with the strongest updrafts.
   Deep-layer shear appears too weak to support a more organized severe
   threat across these regions.

   ...Interior Northwest into the Northern High Plains...
   An upper-level ridge extends from the Southwest/Four Corners region
   into the Great Basin. Scattered thunderstorms are forecast to
   develop later today from parts of eastern OR to the northern High
   Plains on the periphery of this upper ridge. Modestly enhanced
   mid-level flow may support some convective organization. A deeply
   mixed boundary layer with inverted-v type soundings should foster an
   isolated threat for severe wind gusts with the strongest downdrafts.
   With somewhat greater low-level moisture and instability present,
   occasional hail may also occur over the northern High Plains as
   thunderstorms spread eastward this afternoon and evening.