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ACUS02 KWNS 211714

SWODY2

SPC AC 211713



Day 2 Convective Outlook  

NWS Storm Prediction Center Norman OK

1213 PM CDT Sun Apr 21 2024



Valid 221200Z - 231200Z



...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE

SOUTHEASTERN FLORIDA PENINSULA...



...SUMMARY...

Strong to locally severe thunderstorms, capable of marginally severe

wind gusts and hail, will be possible across the central and

southern Florida Peninsula on Monday.



...Synopsis...

A cold front currently draped across the southeastern states to the

northern Gulf will continue to slowly push south/southeast over the

next 24-48 hours. This feature should reach the central to southern

FL peninsula by mid-day Monday. Thunderstorms will likely be focused

along this boundary as it pushes towards far south FL by late Monday

evening. Across the Plains, more isolated thunderstorms will be

possible along a cold front and in the vicinity of a surface low

from northeast CO to the upper MS River Valley.



...South Florida...

Heating of a moist air mass currently in place across south FL,

combined with modest mid-level lapse rates, should support MLCAPE

values between 1000-1500 J/kg ahead of the approaching front.

Although low-level flow will be somewhat weak, winds aloft will be

sufficiently strong to support effective bulk wind differences on

the order of 30-40 knots. Elongated, nearly straight hodographs

should favor splitting cells with the potential for a couple of

right-moving supercells that will pose a large hail threat. However,

storm motions and deep-layer shear vectors should largely be along

the surface boundary, and weak inhibition may favor multiple

thunderstorms along the front by peak heating. These factors could

favor upscale growth of cells into clusters by late afternoon, which

may limit the supercell potential. Regardless, both

discrete/semi-discrete cells and/or more organized clusters should

pose a damaging wind threat given low-level lapse rates approaching

8 C/km by mid afternoon. Latest CAM guidance suggests the severe

threat is most likely to manifest across the southern portion of the

Marginal risk area - particularly in the Miami vicinity as the front

arrives by late afternoon. However, a few strong/severe storms will

be possible late morning further north. 



...Eastern CO to northwest KS...

Dry conditions are prevalent across the Plains in the wake of the

recent frontal passage. However, modified mid-level Pacific moisture

associated with an approaching shortwave trough (currently over

portions of the Pacific Northwest) should overspread parts of the

central to northern High Plains by Monday afternoon. Modest

mid-level moisture atop a deep, well-mixed boundary layer may

support sufficient buoyancy for a few thunderstorms with an

attendant risk for dry downbursts along a weak surface cold front.

Strong to severe outflow gusts are possible based on the forecast

thermodynamic profiles, but do not appear to be probable based on

convective signals in latest guidance and discrepancies between

solutions regarding mid-level saturation (and resultant buoyancy).

Forecast trends will be monitored for the need for low-end,

wind-driven risk probabilities.



..Moore.. 04/21/2024



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