746
ACUS01 KWNS 020102
SWODY1
SPC AC 020100

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0800 PM CDT Mon Sep 01 2025

Valid 020100Z - 021200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN PLAINS AND IN SOUTH-CENTRAL ARIZONA...

...SUMMARY...
Isolated severe thunderstorms may occur across parts of northern and
western Oklahoma this evening, with isolated large hail and damaging
winds the main threats. A marginal severe threat will also be
possible in parts of south-central Arizona.

...Northwest Oklahoma...
At mid-levels on water vapor imagery, a shortwave trough is moving
across the central U.S., embedded in northwesterly flow. At the
surface, a moist airmass is located in the southern and central
Plains with dewpoints in the lower to mid 60s F. The RAP has a
pocket of moderate instability over southern Kansas and northern
Oklahoma with MLCAPE estimated to be in the 1000 to 1500 J/kg range.
Isolated to scattered thunderstorms are ongoing within this pocket
of instability. These storms will persist for a couple more hours,
moving southeastward across parts of western and central Oklahoma.
RAP forecast soundings in north-central Oklahoma early this evening
have 0-6 km near 45 knots. In addition, the Oklahoma City 00Z
soundings has a somewhat steep lapse rates in the 0-3 km layer. This
suggests that isolated severe gust will be possible with the
stronger cells. Hail could also occur.

...Northeast North Dakota...
Northwesterly mid-level flow is evident on water vapor imagery over
parts of the northern Plains. At the surface, a moist airmass in
place with surface dewpoints in the lower to mid 60s F. Isolated
thunderstorms are ongoing near an axis of maximized low-level
convergence in northeastern North Dakota and far northwest
Minnesota. Although a strong storm will be possible this evening,
any severe threat is expected to be limited due to weak deep-layer
shear and poor lapse rates.

...South-central Arizona...
Water vapor imagery shows a plume of mid-level moisture over
south-central Arizona. A few thunderstorms are ongoing within this
plume in the Phoenix area. This convection is located within a
pocket of instability, where SBCAPE values are estimated in the 1000
to 1500 J/kg range, according to the RAP. The 00Z sounding at Tuscon
has a surface dewpoints of 55 F, with 0-3 km lapse rates of 9.7
C/km, with a dry adiabatic temperature profile from the surface to
700 mb. This should be favorable for isolated severe gusts with the
stronger cells for another hour or two.

..Broyles.. 09/02/2025

$$