####018005104####
ACUS01 KWNS 032002

SWODY1

SPC AC 032000



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

0300 PM CDT Fri May 03 2024



Valid 032000Z - 041200Z



...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN A PART OF

WEST TX...



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTH NE TO

THE SOUTH-CENTRAL HIGH PLAINS...



...SUMMARY...

Giant hail, a few tornadoes, and severe wind gusts are possible over

parts of west to central Texas through this evening. Scattered

severe wind and hail are also possible over parts of the central

Great Plains, mainly this evening into tonight.



...20Z Update...

Across parts of west to central TX, initial supercell development is

underway along the I-20 corridor between MAF/ABI. Despite modest

lower-level shear, the large buoyancy and favorable elongation of

the mid to upper portion of the hodograph should foster a few

intense supercells. While left-splits will move northeast,

slow-moving right-movers should progress south-southeast towards the

Concho Valley per recent WoFS and early afternoon CAM guidance.

Giant hail will be the primary threat with some upscale clustering

into the evening promoting potential for significant severe wind

gusts as well. Given the relative early initiation this afternoon

relative to the nocturnal increase in the low-level jet, have

refrained from higher tornado probabilities, although a sub-10%

strong tornado risk remains evident. 



Across the south-central High Plains into southern NE, buoyancy

recovery is well underway ahead of the lower-amplitude shortwave

impulse cross the southern WY/northern CO portion of the Rockies.

Primary change with this outlook is to increase the areal extent of

the cat 2-SLGT risk somewhat to the east and south. This is driven

by higher confidence in strong to isolated severe wind gusts

accompanying multiple potential clusters and QLCSs evolving east

from ongoing convection from the NE Panhandle to the Raton Mesa.



..Grams.. 05/03/2024



.PREV DISCUSSION... /ISSUED 1137 AM CDT Fri May 03 2024/



...Southern Great Plains...

Visible satellite imagery and morning surface analysis shows a very

moist airmass across the Edwards Plateau northward to a residual

effective boundary draped northwest to southeast across the TX South

Plains into central TX.  Near and south of the boundary, low-level

moisture approaching the daily climatological maximum for several

raob sites (reference 12z DRT, BRO, CRP) will contribute to a large

moisture reservoir across west TX by mid-late afternoon.  A

north-south dryline intersecting the differential heating

zone/residual boundary will help focus thunderstorm development

later this afternoon/evening.  Insolation through peak heating will

contribute to very large to extreme buoyancy (3000-4000+ J/kg

MLCAPE) across the Enhanced Risk area.  The nose of a westerly

250-mb speed max (70-90 kt) will move into west TX later this

afternoon/evening acting to elongate hodographs.  Expecting heating

and weak convergence in the vicinity of the aforementioned surface

boundaries to contribute to a weakened cap by mid afternoon.  Widely

scattered to scattered storms are expected to develop through the

early evening according to the latest model guidance.  Large to

giant hail (max size 3-4+ inches in diameter), a few tornadoes, and

severe gusts are possible across the TX South Plains extending

southeastward into portions of the Big Country.  Depending on

storm-scale interactions and local augmentation of the low-level

wind profile, a strong tornado cannot be ruled out, but uncertainty

at these scales precludes a delineated risk area.  Some upscale

growth into a severe cluster is expected across west-central TX this

evening with severe gusts perhaps becoming the primary hazard late.



...Central Plains...

No change in forecast thinking for a large hail/severe gust risk

area across the central Plains.  Though nowhere nearly as moist as

the TX outlook area, a diurnally destabilized plume of moist

advection should support a secondary relative max in severe

potential along/ahead of the cold front and dryline from parts of

eastern CO to western/northern KS and southern NE.  Convection

should develop by mid/late afternoon in a regional convergence

maximum near and northeast of the surface low, with MLCINH weakened

by favorable diurnal heating.  Surface dewpoints in the 40s to low

50s F should be common, with steep surface-500-mb lapse rates,

500-1000 J/kg MLCAPE and well-mixed subcloud layers. 

Effective-shear magnitudes around 40-50 kt indicate potential for

organized convection -- both in quasi-linear form near the front and

initially discrete (but later merging upscale) off the dryline. 

Though activity will encounter a more-stable boundary layer with

time and eastward extent across KS/NE, at least marginal severe-gust

potential may last overnight as far eastward as parts of the

Missouri Valley region.



$$