Nov 1, 2024 1300 UTC Day 1 Convective Outlook
Updated: Fri Nov 1 12:54:35 UTC 2024 (20241101 1300Z Day 1 shapefile | 20241101 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20241101 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 70,566 1,933,858 El Paso, TX...Lubbock, TX...Amarillo, TX...Roswell, NM...Clovis, NM...
Probabilistic Tornado Graphic
20241101 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
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20241101 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
5 % 70,498 1,933,730 El Paso, TX...Lubbock, TX...Amarillo, TX...Roswell, NM...Clovis, NM...
Probabilistic Large Hail Graphic
20241101 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
5 % 70,480 1,933,689 El Paso, TX...Lubbock, TX...Amarillo, TX...Roswell, NM...Clovis, NM...
   SPC AC 011254

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0754 AM CDT Fri Nov 01 2024

   Valid 011300Z - 021200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE SOUTHERN HIGH PLAINS...

   ...SUMMARY...
   Isolated severe hail and/or gusts are possible across parts of the
   southern High Plains, from this evening into the overnight.

   ...Synopsis...
   Today will mark the start of a substantial mid/upper-level pattern
   amplification over the CONUS.  This will be mainly related to a
   strong shortwave trough now digging southeastward over the Pacific,
   offshore from OR, and south of a cyclone now covering the BC Coast
   and adjacent waters.  The cyclone will move inland and devolve to an
   open-wave trough, but also, will phase better with the amplifying
   shortwave trough.  By the end of the period, this should result in a
   major synoptic-scale trough from southern BC over the Pacific Coast
   States and offshore from Baja.  Associated cyclonic flow then will
   cover nearly all the CONUS from the High Plains westward, with
   height falls from the northern/central Rockies to the southern High
   Plains. 

   At the surface, 11Z analysis showed a low over southern QC, with a
   cold front southwestward across western portions of NY/PA/WV,
   eastern KY, middle TN, northern MS, to east and south-central parts
   of TX.  The western part of this frontal zone will decelerate today,
   become more diffuse, and merge with an inland-shifting, older,
   marine/warm frontal zone now lying quasistationary near the LA
   coastline and over deep south TX.  The latter boundary will
   demarcate the northern extent of optimal Gulf moisture, and should
   shift northward/inland through tonight, but remain southeast of west
   TX and eastern NM until day 2.  Another low, with a weak cold front
   arching southward over the central High Plains, will dissipate
   through the period, as lee troughing intensifies just to the west
   (in advance of the strengthening mid/upper trough). 

   ...Southern High Plains...
   Isolated to widely scattered thunderstorms are expected to form over
   portions of far west TX and southeastern NM from late afternoon into
   evening, as gradually increasing boundary-layer moisture becomes
   available to diurnally heated higher terrain in the region. 
   Thunderstorm coverage should increase from late this evening through
   the overnight hours, and begin training within a southwest/
   northeast-oriented plume from far west TX to southern KS.  This
   convective growth will be related to strengthening low-level theta-e
   and moisture, WAA-related large-scale ascent, and weakening MUCINH. 
   The most intense cells embedded in this regime may produce severe
   hail or gusts, but the overall areal severe threat still appears to
   be on the  marginal side, due to lack of greater
   instability/buoyancy.  

   In response to trough amplification aloft over the West, low-level
   warm advection and moisture transport will persist and enlarge into
   the southern High Plains region, with a 30-40-kt LLJ progged to
   develop overnight.  However this will be an early stage of the
   return-flow process under modest lapse rates aloft, with
   considerable residual continental trajectories still involved in low
   levels, and the most-favorable, Gulf-modified parcels not forecast
   to reach the region until day-2 and beyond.  Though upper 50s to low
   60 F surface dewpoints should spread into the Permian Basin region
   of west TX and southeastern NM tonight, the area of strongest lift
   farther northwest will have less moisture.  MUCAPE of 500-800 J/kg
   is expected around the time of most of the convective development,
   increasing to the 1000-1500 J/kg range in non-convective inflow
   sector by the end of the period.  A layer of weaker midlevel flow
   above the LLJ will restrict vertical shear, keeping effective-shear
   magnitudes under 30 kt over most of the area.  As such, any
   supercell processes should be isolated and transient in character,
   especially considering the anticipated upscale evolution to a
   relatively dense convective-precip corridor. 

   ...TX Rio Grande Valley between DRT-LRD...
   Widely scattered to scattered thunderstorms should develop this
   afternoon as the easterly/upslope component of flow impinges on
   higher terrain of the Serranias del Burro of northern Coahuila, and
   adjoining higher slopes in the direction of the Rio Grande. 
   Isolated large hail and damaging gusts are possible, but
   predominantly on the Mexican side of the border.  The boundary layer
   in the valley will be strongly heated and richly moist, with
   dewpoints from the upper 60s to low 70s F.  Given the lack of
   stronger midlevel flow, however, two related factors render a highly
   conditional potential on the TX side:
   1.  Modest deep shear, despite strong veering with height from
   surface into midlevels.  Forecast soundings suggest just 30-35-kt
   effective-shear magnitudes.  
   2.  Uncertainty about whether orographically initiated convection
   can remain organized/severe long enough to reach the border.  

   Early-stage supercells, if any, may not survive far enough eastward
   in that mode, but outflow-dominant/forward-propagating multicellular
   clusters might.  As such, a very conditional severe-gust threat may
   reach TX.  Given the absence of a robust EML and of related MLCINH,
   deep convection also may develop in the warm sector east of the Rio
   Grande, amid strong diurnal heating and rich moisture, but the foci
   for lift are quite unclear at this time.  With all these
   uncertainties, will refrain from an unconditional severe area for
   this outlook cycle.

   ..Edwards/Mosier.. 11/01/2024

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z