SPC Feb 24, 2025 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0630 AM CST Mon Feb 24 2025

Valid 241300Z - 251200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR
SOUTHERN FL INCLUDING THE KEYS...AND OVER PARTS OF EASTERN OR AND
WA...

...SUMMARY...
Scattered strong storms will be possible across the Florida Keys and
into far southern Florida from late afternoon through evening.
Localized damaging gusts or a brief tornado may occur. Isolated
strong winds are also expected from the Oregon Cascades into
southeast Washington.

...Far Southern FL and the FL Keys...
Shortwave trough currently progressing off the TX Coast is expected
to continue eastward across the Gulf today, reaching the FL
Peninsula by early tomorrow morning. Cold mid-level temperatures and
strengthening mid-level flow that accompany this shortwave are
expected to spread over central/southern FL and the FL Keys after
03Z. An attendant surface low attendant will progress quickly
eastward just ahead of the parent shortwave. The general consensus
among the guidance is for this low to be just off the west-central
FL Coast around 00Z before continuing across the central FL
Peninsula and into the western Atlantic by 12Z Tuesday.

Moistening of the low-level airmass is expected ahead of the
shortwave trough and attendant surface low, particularly after 18Z.
Widespread showers throughout the day will likely mitigate buoyancy
somewhat, but little to no surface-based inhibition is expected
south of the warm front (which will extend eastward from the surface
low across the central FL Peninsula) from the late afternoon onward.
Thunderstorm coverage should increase along and ahead of the front
as it gradually pushes eastward. 

Dewpoints near 70s across south FL and the FL Keys will result in
stronger buoyancy and the potential for deeper, more long-lived
updrafts. Strong vertical shear over the region supports the
potential for a few supercells with an attendant risk for damaging
wind gusts and a brief tornado or two. The development of a
low-level convergence zone is possible, which could result in a
favored corridor for strong to severe storms. Currently, this zone
is expected to remain just off south FL Coast, but a few storms in
this area could impact the Keys.

...Interior Pacific Northwest...
Recent satellite imagery shows an intense shortwave trough off the
Pacific Northwest coast, moving quickly northeastward. This
shortwave is forecast to continue northeastward throughout the day,
reaching the coastal Pacific Northwest this afternoon and the
interior Pacific Northwest tonight. A frontal band, with occasional
lightning, is expected to develop along the leading edge of the
strong forcing for ascent associated with this system. Temperatures
could reach the upper 50s/low 60s ahead of this line in northeast
OR/southwest WA amid steep low-level lapse rates and modest
buoyancy. As such, the overall environment supports the potential
for strong downbursts within the line as it moves across the region.

...Eastern Dakotas into the Mid MS Valley...
The low-amplitude shortwave trough currently moving through MT is
expected to continue southeastward today, moving across the northern
Plains and IA before ending the period over IL. A compact but strong
jet streak will accompany this shortwave, with 500-mb winds within
this streak from 90 to 100 kt. The downstream airmass will be dry,
and strong heating/mixing will help push afternoon temperatures into
the upper 50s and low 60s. Despite dry low levels, some modest
buoyancy is possible amid the deep mixing and cold mid-level
temperatures. Consequently, a few shallow thunderstorms are possible
as the strong forcing for ascent attendant to the shortwave
interacts with this limited buoyancy. Small hail and strong outflow
is possible with these storms, but overall coverage is currently
expected to remain too isolated to introduce any probabilities.

..Mosier/Grams.. 02/24/2025

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