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ACUS02 KWNS 161730

SWODY2

SPC AC 161728



Day 2 Convective Outlook  

NWS Storm Prediction Center Norman OK

1228 PM CDT Tue Apr 16 2024



Valid 171200Z - 181200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS NORTHEAST INDIANA

INTO SOUTHEAST LOWER MICHIGAN AND MUCH OF OHIO...



...SUMMARY...

Scattered severe thunderstorms are possible Wednesday afternoon and

evening from southern Lower Michigan into parts of the Ohio Valley.

A more isolated severe threat may materialize across parts of

Tennessee Valley into the Southwest as well as parts of the

east-central Plains and Ozark Plateau.



...Synopsis...

The upper-level wave and attendant surface low currently over the

central Plains/Midwest are forecast to weaken over the next 24-48

hours as they gradually lift to the northeast. A trailing surface

cold front associated with the low is forecast to push east across

the Great Lakes region through the day it becomes increasingly

influenced by mean westerly flow. This boundary should be the focus

for strong to severe thunderstorm development by late morning/early

afternoon across IN/OH and lower MI. Additional thunderstorm

development is anticipated by peak heating across portions of the TN

Valley as a residual outflow boundary migrates east. To the west

across the Plains, a warm advection regime should become established

by early evening as a surface low begins to deepen ahead of an

approaching upper-level wave. Isolated strong to severe

thunderstorms are possible within the warm advection regime across

parts of the Ozarks into the east-central Plains. 



...Midwest/Great Lakes...

Broken cloud cover is anticipated Wednesday morning across the

Midwest/Great Lakes as a mid-level dry slot overspreads the region

in the wake of Tuesday night's convection. The north/northeast track

of the decaying surface low should allow for low to mid 60s

dewpoints to spread north into IN/OH and lower MI by late morning

ahead of the approaching cold front. Thunderstorm development may

occur by mid-morning across portions of IN, but the development and

intensification of any convection will be dependent on the degree of

subsidence within the dry slot. Diurnal heating of the low-level air

mass should allow for 1000-2000 J/kg SBCAPE by early afternoon with

decreasing inhibition. Consequently, more robust convection is

likely by early afternoon across lower MI into western OH.

Deep-layer flow off the front should favor initially discrete cells

within a broken line of storms with an attendant hail and tornado

risk. Steepening low-level lapse rates, combined with 40-50 knot

mid-level flow, should support an increasing damaging wind threat by

late afternoon. Upscale growth into one or more clusters is probable

by late afternoon into the evening hours across eastern OH and far

western PA given strong forcing along the front and similar storm

and boundary motions. Further south into the OH River Valley,

thunderstorm development is less certain given increasing

displacement from the stronger forcing for ascent. However, a

conditionally favorable environment for organized convection is

forecast, which should support a more isolated severe threat. 



...Tennessee Valley region...

A residual outflow boundary from Tuesday night's convection is

expected to push east through the morning hours, reaching the

eastern TN Valley into northern AL/MS by peak heating. Thunderstorm

development and/or re-intensification is possible - especially

across AL/MS/GA where latest CAMs show reasonable agreement in

redevelopment as SBCAPE increases to around 1500 J/kg. While

low-level flow is forecast to be weak, 30-40 knot westerlies aloft,

combined with steepening low-level lapse rates by late afternoon,

should support a few stronger cells/clusters with an attendant

hail/wind risk. 



...Southwest Missouri to Northeast Kansas...

An upper disturbance currently approaching northern MT is forecast

to migrate southeast over the next 48 hours. Surface pressure falls

over the Plains in response to the approach of this feature will

strengthen southerly low/mid-level winds on the western periphery of

a warm/moist air mass over the southern Plains/lower MS Valley -

especially by early evening as the nocturnal jet strengthens.

Concurrently, a cold air mass will begin migrating south along the

High Plains. Thunderstorms may develop within the warm advection

regime on the northern fringe of the returning moisture during the

00-06 UTC period across parts of the Ozark Plateau. A second round

is probable later overnight (during the 08-12 UTC period) as the

cold front impinges on the returning moisture across northeast KS.

For both regimes, sufficient deep-layer flow should be in place to

support organized cells with a severe hail risk.



..Moore.. 04/16/2024



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