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ACUS01 KWNS 010601

SWODY1

SPC AC 010600



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

0100 AM CDT Wed May 01 2024



Valid 011200Z - 021200Z



...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF

WEST AND CENTRAL TEXAS NORTHWARD INTO WESTERN OKLAHOMA...THE EASTERN

TEXAS PANHANDLE AND SOUTH-CENTRAL KANSAS...



...SUMMARY...

Severe storms with large hail up to 3 inches in diameter, wind

damage, and a few tornadoes will be possible this afternoon and

evening across parts of the southern and central Plains. The

greatest severe threat is expected from north-central Kansas

southward across western Oklahoma, the eastern Texas Panhandle into

northwest and west-central Texas.



...Southern and Central Plains...

An upper-level trough will move across the Intermountain West and

Desert Southwest today, as mid-level flow remains southwesterly

across the southern and central Plains. At the surface, a low is

forecast to deepen across southeast Colorado, with a warm front

moving northward across central and north-central Kansas. A dryline

will be located from southwest Kansas southward into west Texas. A

moist airmass, with surface dewpoints in the mid to upper 60s F,

will be located from the dryline eastward across much of the

southern Plains. As surface heating takes place during the day,

isolated convective initiation is expected across the moist airmass.

More vigorous convective development will develop during the mid to

late afternoon from the vicinity of the warm front in central

Kansas, southward along the dryline into the southern Plains.



Current model runs suggest that the storms will develop in the

eastern Texas Panhandle and move into western Oklahoma. These storms

are forecast to remain semi-discrete. RAP forecast soundings in

western Oklahoma at 00Z/Thursday have MLCAPE of 3000 to 4000 J/kg,

with 0-6 km shear in the 25 to 30 knot range, and 700-500 mb lapse

rates near 8 C/km. This should support storms with some supercell

structure, and a potential for large to very large hail up to 3

inches in diameter. 0-3 km storm-relative helicity is forecast to be

in the 200 to 250 m2/s2 range to the east of the dryline from

southwest Kansas into northwest Texas, suggesting tornadoes will be

possible. 



Further north into central and north-central Kansas, model forecasts

suggest that initiation will remain isolated due to a lack of

large-scale ascent. By 00Z/Thursday, RAP forecast soundings near

Salina have 0-6 km shear around 50 knots, with 0-3 km storm-relative

helicity in the 300 to 400 m2/s2 range. This would be favorable for

a tornado threat, if cells can initiate along the warm front. The

current thinking is that the models may be underdone with convection

along the warm front. If convergence is strong enough, a discrete

supercell could initiate during the late afternoon or early evening.

The strengthening low-level jet would make low-level shear favorable

for a tornado or two in central or north-central Kansas. Large to

very large hail would also be possible with any cell that can

develop on the warm front. These threats appear conditional.



Further south across northwest and west-central Texas, a linear MCS

is expected to develop. MLCAPE to the east of the dryline is

forecast to be in the 3000 to 4000 J/kg range, with 700-500 mb lapse

rates near 8 C/km. This, combined with 0-6 km shear in the 25 to 30

knot range may support storm rotation early in the event. Cells that

rotate can be expected to have large to very large hail. However, a

rather quick transition to linear mode is forecast in the late

afternoon. This linear MCS may be associated with severe wind gusts

along the leading edge. The isolated wind-damage threat should

affect areas in central Texas by mid to late evening.



..Broyles/Thornton.. 05/01/2024



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