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ACUS01 KWNS 171645

SWODY1

SPC AC 171644



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

1144 AM CDT Wed Apr 17 2024



Valid 171630Z - 181200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF

SOUTHERN LOWER MICHIGAN INTO THE OHIO VALLEY...



...SUMMARY...

Scattered thunderstorms capable of producing damaging winds, large

hail, and a few tornadoes should develop across parts of the Ohio

Valley and Lower Great Lakes this afternoon. Thunderstorms with

mainly a large hail threat may occur tonight over parts of the

central Plains.



...Synopsis...

Satellite imagery continues to show a negatively tilted upper trough

extending from the Upper Midwest into the OH Valley. Surface low

associated with this trough is currently over northeast WI. An

occluded front extends southwestward from this low to a triple point

in the southern Lake Michigan vicinity. From this triple point, a

warm front extends east-southeastward across southern Lower MI into

northeast OH and a cold front extends south-southwestward across

western IN and southern IL. Strong to severe thunderstorms are

anticipated along and ahead of the cold front as it moves across the

OH Valley and Lower MI today and tonight. This cold front then

becomes stationary as it becomes more east-west orientated over AR

before transitioning to a warm front OK. 



...Lower Michigan into the Ohio/Tennessee Valleys...

As mentioned in recently issued MCDs #469 and #470, the showers and

isolated thunderstorms currently ongoing along and ahead of the cold

front are expected to gradually intensify as the downstream air mass

diurnally destabilizes. Stronger forcing for ascent is anticipated

across Lower MI, which will favor quicker upscale growth into one or

more bowing segments. As such, primary severe risk over Lower MI is

expected to be damaging gusts from 45 to 65 mph.



Farther south, less forcing for ascent and generally modest buoyancy

should favor less storm coverage than areas farther north, with a

more cellular storm mode anticipated as well. This region will be

displaced north of the stronger upper-level flow, but the enhanced

mid-level flow in place should still be sufficient for updraft

organization and the potential for a few supercells.  Primary risk

with these storms will be hail around 1" and damaging gusts from 45

to 65 mph, but low-level flow is expected to be strong enough to

support some tornado potential as well.



Continued development along and ahead of the front could lead foster

a transition to a more linear mode with eastern extent this evening.

Damaging gusts and line-embedded tornadoes will still be possible.



...Eastern KS into the Mid/Lower MO Valley...

An upper-level trough will move eastward across the north-central

CONUS tonight. Isolated thunderstorms are possible later this

evening in central NE. Expectation is for these storms to be

elevated, but some hail is possible.



A 40-45 kt southerly low-level jet will develop this evening across

parts of the southern/central Plains in response to the approaching

trough. Thunderstorms should eventually initiate near the northern

edge of the low-level jet late this evening from central KS into far

southeast NE. Ample buoyancy, and strong shear in the cloud-bearing

layer should support some threat for large hail with this mainly

elevated convection. If convection can grow upscale into a small

bowing cluster, then isolated damaging winds may also occur.



...Mid-Atlantic...

Across the Mid-Atlantic, filtered daytime heating will contribute to

a well-mixed boundary layer and steep low-level lapse rates,

resulting in modest buoyancy this afternoon. A few thunderstorms may

move into the region off the higher terrain, with occasionally

damaging gusts possible. Given the limited instability, the overall

severe wind threat will likely remain isolated.



...Texas Hill Country into Northwest TX...

Isolated thunderstorms may develop late this afternoon and early

evening across parts of south-central into central TX along the

dryline. If any convection can be sustained, it could produce severe

winds and hail, but the threat currently appears too uncertain to

introduce any severe probabilities.



..Mosier/Bentley.. 04/17/2024



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