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ACUS02 KWNS 130542

SWODY2

SPC AC 130540



Day 2 Convective Outlook  

NWS Storm Prediction Center Norman OK

1240 AM CDT Sat Apr 13 2024



Valid 141200Z - 151200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF PA TO

EAST OH...



...SUMMARY...

Isolated to scattered severe thunderstorms are possible from late

afternoon into the evening on Sunday, across eastern Indiana into

the Northeast States. Damaging winds should be the primary hazard,

but a tornado or two and large hail are also possible.



...Northeast States to eastern IN...

A mid-level jetlet attendant to a low-amplitude shortwave impulse

should progress across the northern Great Lakes and Ontario into New

England by Sunday evening. Weak cyclogenesis should occur with the

surface low tracking east across parts of NY. An attendant cold

front should arc westward and progress southeastward. 



A pronounced elevated mixed layer across the Midwest and southern

Great Lakes will shift southeastward into the Mid-Atlantic and

Southeast States. This elevated mixed layer will likely cap

surface-based convection until near/after peak heating along the

west/east-oriented cold front. 00Z RRFS/NAM soundings appear

relatively reasonable with this evolution as modified low-level

moisture return emanating from the southern Great Plains struggles

to reduce MLCIN until cooling aloft advects in from the

west-northwest. Other guidance may be too moist within the boundary

layer given upstream observations and 36 hours of air mass

modification remaining. Still, a corridor of MLCAPE reaching

1000-1500 J/kg will probably develop in IN/OH given the initially

steep mid-level lapse rates. This buoyancy plume will subside with

eastern extent towards the DE Valley.



Hodographs across the region should be dominated by low-level

curvature enlargement, especially with eastern extent. However, weak

speed and directional shear components are expected above that

within the buoyancy layer. Maturing cells will attempt to form

supercell structures, but given the nearly parallel orientation of

the front with respect to the deep-layer westerly flow regime,

convective mode should favor west/east-oriented clusters. These

should largely progress south-southeast amid the undercutting nature

of the composite front and emerging convective outflows. Due to the

initially steep mid-level lapse rates and enlarged low-level

hodographs, there is concern for a brief supercell tornado and

isolated hail threat. Though with the limiting factors, it appears

damaging winds should be the primary hazard during the evening

before convection wanes with southern extent overnight.



..Grams.. 04/13/2024



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