Source: US National Oceanic and Atmospheric Administration
SPC AC 211925
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0225 PM CDT Wed May 21 2025
Valid 231200Z – 241200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE CENTRAL AND SOUTHERN PLAINS…WESTERN TEXAS…AND THE EASTERN
FLORIDA PENINSULA…
…SUMMARY…
A few strong to severe storms are possible across portions of the
central Plains, western Texas, and across southeast Florida on
Friday.
…Synopsis…
Upper ridging will persist over the central CONUS as a mid-level
trough meanders along the East Coast and a second upper trough
traverses the Interior West on Friday. Surface high pressure will
dominate much of the central, northern, and eastern CONUS while a
surface low develops over the central High Plains. Ahead of the
surface low, adequate moisture return within a low-level warm-air
advection regime will encourage thunderstorm development across
portions of the central and southern Plains, with a few strong
storms possible. Strong to potentially severe storms may also form
over western TX as boundary layer mixing encourages the eastward
advancement of the dryline, where low-level convergence will be
maximized. A few strong storms may develop across eastern portions
of the FL Peninsula ahead of a stalled frontal boundary.
…Portions of the central and southern Plains…
Multiple rounds of deep-moist convection are likely along a diffuse
baroclinic boundary across the central Plains, driven primarily by a
warm-air advection regime. Strong to severe storms are most likely
during the afternoon and evening hours. By late afternoon,
supercells may develop off of the higher terrain of northeastern
Colorado as upslope flow and diurnal heating maximize lift amid 8-9
C/km mid-level lapse rates and elongated hodographs. These storms
may progress east-southeastward through the overnight hours,
accompanied by some threat for large hail.
…Portions of western Texas…
As the dryline mixes eastward by afternoon peak heating, isolated
but strong thunderstorms may develop atop a dry boundary layer,
which may deepen to 700 mb. Given some hodograph elongation and over
30 kts of effective bulk shear, some of these storms may develop
into organized multicells. 9 C/km lapse rates characterizing the
boundary layer will support severe gust potential with the stronger
storms.
…Portions of the eastern Florida Peninsula…
Thunderstorms should develop ahead of a stalled front during the
afternoon, where rich low-level moisture beneath modest mid-level
lapse rates will contribute to over 2000 J/kg MLCAPE. With modestly
elongated hodographs in place, multicells may form, accompanied by a
sparse hail/wind threat.
..Squitieri.. 05/21/2025
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