ACUS03 KWNS 110729
SWODY3
SPC AC 110728
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0228 AM CDT Sun May 11 2025
Valid 131200Z - 141200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
The risk for severe thunderstorms currently appears negligible
across the U.S. Tuesday through Tuesday night.
...Discussion...
It appears that significant mid/upper-level troughing progressing
inland of the U.S. Pacific coast may dig as far south as the lower
Colorado Valley, and suppress ridging within a belt of westerlies
emanating from the subtropical eastern Pacific, across the
southwestern international border area. Thereafter, models indicate
that the perturbation will turn eastward across the Intermountain
West later Tuesday through Tuesday night, with intensifying difluent west-southwesterly mid/upper flow overspreading the southern Rockies
by 12Z Wednesday.
In lower levels, modestly deep surface troughing to the lee of the
Rockies may continue to slowly shift eastward across the Great
Plains. However, in the wake of broad, weak negatively tilted
mid/upper troughing shifting east of the Mississippi Valley, toward
the Atlantic coast at a slower pace than the upstream trough,
strengthening low-level flow (up to 30-40 kt around 850 mb) is
forecast to maintain a pronounced westerly component across the
southern Great Plains into lower Mississippi Valley. This will
continue to impede boundary-layer moisture return off the Gulf into
the Great Plains, though evapotranspiration may contribute to
moistening beneath the leading edge of a plume of warm elevated
mixed-layer air advecting eastward across the central and southern
Great Plains.
Downstream, models indicate that there will be gradual further
deepening of broad, weak surface troughing across much of the
Southeast. However, the plume of seasonably high moisture content
air emanating from the lower latitudes is forecast to generally
shift east of the south Atlantic coast during the day Tuesday,
though this may be slower to occur across southeast coastal areas of
the Florida Peninsula.
...Intermountain West into Great Plains...
Models suggest that destabilization beneath an elongated mid-level
cold pool, trailing the surface cold front, may contribute to
scattered, generally weak/diurnal thunderstorm activity across the
northern Rockies and intermountain region, into the vicinity of the
northern Sierra Nevada.
Near the surface troughing across the Dakotas, it appears that a
strongly heated and deeply mixed boundary may become characterized
by 40-50 F surface temperature/dew point spreads, but with
thermodynamic profiles still supportive of CAPE on the order of
500-1000 J/kg. High-based thunderstorm development appears possible
near/after peak heating, which could pose some risk for locally
strong surface gusts. However, the extent of this potential remains
unclear, and too uncertain to introduce even low severe
probabilities at the present time.
...Ohio Valley/Mid Atlantic/Southeast...
Scattered, largely diurnal thunderstorm activity will again be
possible beneath the weak/weakening mid-level troughing. Stronger
convection may focus along the sea breeze near southeastern Florida
coastal areas, and perhaps across parts of the mid and southern
Atlantic Piedmont, where at least modest boundary-layer
destabilization may occur. However, it is not yet clear that this
will be accompanied by an appreciable risk for severe weather.
..Kerr.. 05/11/2025
$$
= = =
To unsubscribe from WX-STORM and you already have a login, go to
https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at
cnovy@cox.net and ask to be removed from WX-STORM.
--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)
