SPC Apr 1, 2025 1630 UTC Day 1 Convective Outlook

SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1135 AM CDT Tue Apr 01 2025

Valid 011630Z - 021200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN/CENTRAL PLAINS...

...SUMMARY...
Rapid, intense thunderstorm development should occur this evening
over parts of the central/southern Plains. A few supercells with a
risk for very large hail and strong tornadoes appear possible,
particularly across central Oklahoma into eastern Kansas. A line of
thunderstorms should also develop and pose a threat for
severe/damaging winds across eastern Kansas into western Missouri
tonight.

...OK-TX...
Visible-satellite imagery shows stratus and moisture streaming
northward through TX into OK on strengthening southerly low-level
flow.  Increasingly rich moisture around 850 mb layer will mix
downward beneath an initially strong capping inversion sampled on 12
UTC area observed soundings.  Heating of an increasingly moist and
destabilizing boundary layer will result in a very unstable airmass
late this afternoon into the early evening.  Models show lower 60s
dewpoints reaching I-40 by early evening.  Very strong and favorable
wind profiles for supercells will support rapid supercell
development if storms initiate (22-01 UTC).  Models differ on the
diurnal storm coverage casting considerable uncertainty---but some
guidance has trended towards at least one to a few dryline discrete
supercells across the southern Great Plains.  Very large hail and
tornadoes would be the primary hazards.  Enlarged and elongated
hodographs would support the potential for strong tornadoes provided
a sustained supercell develops late this afternoon/evening.  Later
tonight, models show richer moisture with a very unstable airmass
being maintained.  Of particular note is forcing for ascent
perturbing the airmass from north-central TX into OK near and ahead
of the front.  A nocturnal risk for renewed supercell development
capable of all hazards would be strongly favored with any activity
not undercut by the front---mainly during the 08-12 UTC period.  

...Central Plains into Missouri...
Not much change in thinking from the prior forecast.  The cap is
forecast to erode on the northern periphery of more appreciable
moisture over the central High Plains by late afternoon or early
evening.  At least isolated thunderstorms are expected to develop
near the triple point in the south-central KS/north-central OK
vicinity, and subsequently spread quickly northeastward.  Moderate
to locally strong instability, coupled with 50-60 kt of effective
bulk shear, will easily support supercells, with an associated
threat for very large hail (up to 2-3 inches in diameter).  As the
southerly low-level jet markedly increases this evening, hodographs
will enlarge and become elongated, with ample effective SRH to
support tornadoes with any sustained supercells. Given the strength
of the low-level flow expected (50-60+ kt southerly jet at 850 mb)
and degree of low-level shear forecast, strong tornadoes appear
possible.  A line of convection should also erupt along the cold
front in north-central to northeast KS tonight, and spread eastward
into parts of western MO through early Wednesday morning. Even with
the time of night, the overall environment appears quite favorable
for severe/damaging winds, including the potential for isolated 75+
mph gusts. 

...Central Valley of California...
With cold air aloft associated with the upper trough over the
western CONUS, weak instability could develop by peak afternoon
heating to support isolated strong thunderstorms. These could pose a
risk for small hail, gusty winds, and perhaps a brief tornado
across portions of the Central Valley in CA.

..Smith/Moore.. 04/01/2025

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