130
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.

$$