May 13, 2024 1300 UTC Day 1 Convective Outlook
Updated: Mon May 13 12:49:36 UTC 2024 (20240513 1300Z Day 1 shapefile | 20240513 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20240513 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 91,732 15,285,376 Houston, TX...San Antonio, TX...Austin, TX...Baton Rouge, LA...Mobile, AL...
SLIGHT 123,200 7,500,867 New Orleans, LA...Corpus Christi, TX...Shreveport, LA...Tallahassee, FL...Metairie, LA...
MARGINAL 273,013 30,095,487 Dallas, TX...Jacksonville, FL...Memphis, TN...Fort Worth, TX...Arlington, TX...
Probabilistic Tornado Graphic
20240513 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 % 76,476 6,918,287 New Orleans, LA...Baton Rouge, LA...Mobile, AL...Tallahassee, FL...Metairie, LA...
2 % 233,199 26,507,140 Houston, TX...San Antonio, TX...Jacksonville, FL...Austin, TX...Corpus Christi, TX...
Probabilistic Damaging Wind Graphic
20240513 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 53,360 6,566,986 Baton Rouge, LA...Mobile, AL...Lafayette, LA...Beaumont, TX...The Woodlands, TX...
30 % 75,570 11,550,984 Houston, TX...Baton Rouge, LA...Mobile, AL...Pasadena, TX...Lafayette, LA...
15 % 93,082 8,532,900 San Antonio, TX...Austin, TX...New Orleans, LA...Corpus Christi, TX...Tallahassee, FL...
5 % 286,058 28,975,491 Dallas, TX...Jacksonville, FL...Memphis, TN...Fort Worth, TX...Arlington, TX...
Probabilistic Large Hail Graphic
20240513 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 113,999 16,010,129 Houston, TX...San Antonio, TX...Austin, TX...New Orleans, LA...Corpus Christi, TX...
30 % 36,119 9,262,119 Houston, TX...San Antonio, TX...Austin, TX...Pasadena, TX...College Station, TX...
15 % 128,108 10,085,804 New Orleans, LA...Corpus Christi, TX...Baton Rouge, LA...Shreveport, LA...Metairie, LA...
5 % 322,813 33,381,411 Dallas, TX...Jacksonville, FL...Memphis, TN...Fort Worth, TX...Arlington, TX...
   SPC AC 131249

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0749 AM CDT Mon May 13 2024

   Valid 131300Z - 141200Z


   Severe thunderstorms are expected today from central and east Texas
   across the Gulf Coast states. The potential exists for multiple
   corridors of significant wind gusts, very large hail, and a few

   ...Central/eastern Texas...
   The region will be influenced by moderately strong cyclonically
   curved westerlies within the base of the central Plains/Lower
   Missouri Valley-centered upper-level trough. Some northward spread
   of a very moist near-coastal air mass will occur today ahead of an
   upstream southeastward-moving cold front and weak surface wave.
   Beneath steep mid-level lapse rates (reference 12z observed
   soundings from DFW/CRP), strong destabilization is expected into the
   afternoon as multi-layer cloud cover becomes more scattered, with
   upwards of 2000-4000 J/kg MLCAPE across much of south-central and
   east/southeast Texas.

   A belt of stronger mid-level flow will overspread the region, with
   elongated, straight hodographs supporting splitting supercells as an
   initial storm mode. Large hail will be the main threat with these
   storms, with some of the largest stones potentially reaching 2-4
   inches in diameter where sustained supercell structure can develop
   and persist. With time, storms should grow upscale into an
   east/southeastward-moving MCS later in the afternoon and evening as
   they move toward the coastal plain and interact more favorably with
   the baroclinic boundary. By this point, severe gusts become the
   primary threat, with a couple of QLCS tornadoes also possible.

   ...Gulf Coast/Southeast...
   A quasi-linear storm cluster persists this morning across far
   southern Alabama and the Florida Panhandle, on the immediate cool
   side of a near-coastal warm front that will continue to develop
   north-northeastward through the day. This cluster may grow further
   upscale with a continued severe risk through the morning,
   particularly with 75-100 miles of the Gulf of Mexico. This includes
   the potential for all severe hazards including damaging winds, large
   hail and some tornado risk. Additional storm development and
   intensification is possible today along the outflow reinforced
   effective front that extends westward across far southern
   Mississippi and southern Louisiana.

   Additionally, linearly organized storms moving out of Texas could
   approach some of these same areas again late tonight. Any such
   secondary/tertiary rounds of severe risk will depend upon how far
   south the effective baroclinic zone has been shunted southward by
   convection through the afternoon/early evening, likely confining any
   such severe potential late tonight to more immediate coastal areas.

   ...Portions of the southern Plains into the Ozarks...
   Showers and thunderstorms should linger across much of the southern
   Plains into the Ozarks this morning to at least mid-afternoon. Weak
   surface low development is anticipated across Missouri/Arkansas
   later in the day, which will encourage modest low-level moisture
   advection beneath gradually steepening mid-level lapse rates. SBCAPE
   should rise into the 1000-1500 J/kg range later in the afternoon.
   Deep-layer shear is not expected to be overly strong with northward
   extent, though some elongation of straight hodographs suggests that
   multicells or brief, transient supercells may develop and produce
   isolated severe hail and/or wind.

   ...Florida Peninsula...
   To the south of potential MCS influences across northern Florida,
   surface temperatures are expected to rise into the 80s F amid
   dewpoints around 70 F. Though mid-level lapse rates will be
   relatively poor, the strong surface heating of the moist air mass
   will boost SBCAPE into the 1000-2000 J/kg range amid 30-40 kt of
   effective bulk shear. Multicells and transient supercells are
   expected to initiate during the afternoon, especially along
   sea-breeze boundaries, with isolated instances of hail and damaging
   winds gusts possible.

   ...Northern Montana...
   A few strong storms could occur from mid-afternoon through early
   evening, influenced by a low-amplitude mid-level disturbance and a
   modestly moist/unstable boundary layer. Some stronger wind
   gusts/hail could occur, but modest-strength low/mid-tropospheric
   winds should keep organized severe potential low.

   ..Guyer/Broyles.. 05/13/2024