Source: US National Oceanic and Atmospheric Administration
Day 4-8 Severe Weather Outlook Issued on May 15, 2025
Updated: Thu May 15 09:01:03 UTC 2025
.
D4
Sun, May 18, 2025 – Mon, May 19, 2025
D7
Wed, May 21, 2025 – Thu, May 22, 2025
D5
Mon, May 19, 2025 – Tue, May 20, 2025
D8
Thu, May 22, 2025 – Fri, May 23, 2025
D6
Tue, May 20, 2025 – Wed, May 21, 2025
(All days are valid from 12 UTC – 12 UTC the following day)
Note: A severe weather area depicted in the Day 4-8 period indicates 15%, 30% or higher probability for severe thunderstorms within 25 miles of any point.
PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to: 1) large differences in the deterministic model solutions, 2) large spread in the ensemble guidance, and/or 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears unlikely (i.e., less than 15%) for the forecast day.
Forecast Discussion
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 150858
SPC AC 150858
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0358 AM CDT Thu May 15 2025
Valid 181200Z – 231200Z
…DISCUSSION…
Medium-range guidance indicates that the persistent, prominent
mid/upper ridging across the mid-latitude and subtropical eastern
Pacific will become suppressed late this coming weekend into early
next week, before breaking down through the remainder of this
period. As it does, amplified downstream troughing is forecast to
emerge from the Intermountain West. Sunday, this may commence
gradually, with one significant lead short wave perturbation
pivoting north-northeast of the southern Rockies, accompanied by
cyclogenesis across eastern Colorado, as an upstream perturbation
continues to dig toward the Four Corners region. It appears that
this trailing perturbation will then pivot across the southern
Rockies through the central/southern Great Plains by late Monday,
perhaps accompanied by renewed cyclogenesis across the Texas
Panhandle into central Great Plains.
Both days, the dryline and warm front may provide focus for
organized severe convective development, including supercells, in
the presence of strong deep-layer shear and thermodynamic profiles
characterized by steep lapse rates and sizable CAPE. It appears
that a substantive risk for strong to severe thunderstorms will
persist into at least Tuesday, within a broadening warm sector as
the cyclone and associated mid-level troughing shift a bit more
rapidly eastward across the middle Mississippi Valley.
Convective potential becomes more unclear Wednesday into Thursday as
the cyclone likely weakens and synoptic developments become more
uncertain across the East.
..Kerr.. 05/15/2025
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