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January 24th-25th, 2023 | Severe Weather


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  • Meteorologist

SPC mentions a possible strong tornado threat. I was thinking it would be possible but I didn't think the warm sector really eclipsed land enough. Something to watch.


   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0228 AM CST Sun Jan 22 2023

   Valid 241200Z - 251200Z


   Severe thunderstorms are possible, perhaps near mid to upper Texas
   coastal areas early Tuesday afternoon, but more likely across
   southeastern Louisiana and Mississippi through southern Alabama and
   the western Florida Panhandle Tuesday night.  These may become
   capable of producing tornadoes and locally damaging wind gusts.

   Models suggest that an initially prominent mid-level high over the
   southern mid-latitude eastern Pacific will weaken, with a new high
   beginning to form in higher latitudes, within persistent
   larger-scale ridging.  This ridging is forecast to continue to build
   north-northeastward across British Columbia, Yukon and parts of the
   Northwest Territories through this period, with amplified troughing
   being maintained downstream, along and east of the Rocky Mountains. 
   The most prominent embedded short wave perturbation within this
   regime, initially in the base of this troughing, is forecast to 
   accelerate east-northeastward out of southwest Texas by early

   Aside from the NCEP SREF (with the 22/03Z run remaining a notable
   slower outlier), most model output indicates that the perturbation
   will rapidly progress across the southern Great Plains into the Mid
   South by late Tuesday night, accompanied by significant surface
   cyclogenesis near mid/upper Texas coastal areas into and through the
   lower Mississippi Valley and Mid South.  As this occurs, an intense
   west-southwesterly mid/upper jet (including 90-100 kt around 500 mb)
   is forecast to develop across the lower Mississippi through
   Tennessee Valleys by 12Z Wednesday.  In association with the
   developing cyclone, a southerly low-level jet may include speeds
   increasing in excess of 50-70 kt to the east of the lower
   Mississippi Valley during a period of more rapid deepening Tuesday
   evening.  A similar earlier period of cyclone deepening and wind
   field intensification is also appearing increasingly probable near
   mid/upper Texas coastal areas early Tuesday afternoon.

   ...Texas coastal areas through central Gulf Coast states...
   Given the synoptic forcing, the presence of an initially cool/stable
   boundary layer across much of the Gulf Coast region is the primary
   limiting factor to the development of a more substantive risk for
   severe thunderstorms Tuesday through Tuesday night.  The boundary
   layer across much of the northern Gulf of Mexico will also still be
   in the process of modifying from prior frontal intrusions, but it
   does appear that mid/upper 60s F surface dew points may rapidly
   advect toward northwestern through north central Gulf coastal areas.

   Boundary-layer destabilization near, if not inland of, mid into
   upper Texas coastal areas may contribute to an environment conducive
   to supercell development around midday into early afternoon. 
   Thereafter, boundary-layer moistening within at least a narrow
   inland corridor across southeastern Louisiana into south central
   Alabama still seems probable Tuesday evening through Tuesday night. 
   Beneath a plume of modestly steepening lapse rates, this is expected
   to contribute to a corridor of boundary-layer destabilization
   sufficient to support organized convective development.  This may
   include a developing line of storms along a pre-frontal confluence
   zone, perhaps preceded by more discrete supercells.

   While it appears possible that moist adiabatic to more stable
   near-surface lapse rates could tend to minimize the number of
   potentially severe storms, even with only somewhat better
   boundary-layer modification than currently forecast, a more
   substantive severe weather threat may still develop.  Very large and
   clockwise-curved low-level hodographs forecast to develop within the
   warm sector will contribute to wind profiles potentially supportive
   of strong tornadoes in supercell storms.


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  • Meteorologist

Long-duration event tomorrow. Extreme shear along the coast. Big issue is storm mode and the warm sector being not far onto shore. But that extreme shear should make embedded tornadoes pretty easy to come across.




Edited by ClicheVortex2014
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  • The title was changed to January 24th-25th, 2023 | Severe Weather
  • Meteorologist

Tornado watch coming

MD 93 graphic

Mesoscale Discussion 0093
   NWS Storm Prediction Center Norman OK
   1016 AM CST Tue Jan 24 2023

   Areas affected...Middle/Upper TX Coast...Far Southwest LA

   Concerning...Severe potential...Tornado Watch likely 

   Valid 241616Z - 241815Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Environmental conditions along the middle/upper TX coast
   into southwest LA will support supercells capable of all severe
   hazards, including tornadoes, this afternoon. A Tornado Watch will
   be needed along the middle /upper TX coast to southwest LA within
   the next hour or so.

   DISCUSSION...Recent surface analysis places a low about 30 miles
   northwest of NIR in northern Bea County TX. A warm front extends
   east-northeastward from this low through Galveston Bay and then off
   the far southeast TX coast. The air mass south of this warm front is
   characterized by temperatures in the low 70s/upper 60s and dewpoints
   in the mid/upper 60s. Expectation is for this front to gradually
   lift northward as the surface low transitions east-northeastward. As
   it does, modest surface-based buoyancy is anticipated across the
   middle and upper TX coast. 

   Robust low-level wind fields are also in place, with mesoanalysis
   estimating 50-60 kt at 850 mb from CRP vicinity northward into
   southeast TX. Southeasterly surface winds exist throughout the warm
   sector, resulting in strong low-level vertical shear. Recent VAD
   profiles from CRP and HGX sampled 300 m2/s2 and 800 m2/s2 of 0-1 km
   storm-relative helicity. 

   Increasing thunderstorm coverage is anticipated throughout the
   afternoon, and these environmental conditions are expected to
   support strong to severe thunderstorms. More linear development is
   anticipated along the front south of the low, but some potential for
   discrete warm-sector development exists as well. Any discrete storms
   would likely become supercellular with the potential for all severe
   hazards, including tornadoes. Given the strong low-level shear, a
   strong tornado is possible. Large hail and damaging wind gusts are
   also possible. As a result, a Tornado Watch will be needed along the
   middle/upper TX coast in far southwest LA.


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  • Meteorologist

Extreme shear at Houston. 600 m2/s2 at 0-500m. Instability is likely to be marginal all day, so localized higher instability will be key to storms being able to take advantage of the shear, as well as boundaries/mergers


Edited by ClicheVortex2014
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  • Meteorologist

Debris signature. Rotation doesn't look convincing so,

1) tornadic rotation was below this beam scan. Unlikely because this is looking at 1400 feet agl.

2) brief tornado occurred between radar scans


Edited by ClicheVortex2014
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