Subj : DAY1SVR: Enhanced Risk
To   : All
From : Mike Powell
Date : Tue May 30 2023 16:39:00

ACUS01 KWNS 301926
SWODY1
SPC AC 301925

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0225 PM CDT Tue May 30 2023

Valid 302000Z - 311200Z

....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING OVER PARTS OF SOUTHWEST NEBRASKA...WESTERN
KANSAS...EASTERN COLORADO...AND THE TEXAS/OKLAHOMA PANHANDLES...

....SUMMARY...
Severe thunderstorm gusts -- some reaching at least 75 mph -- are
possible from this afternoon into early evening over portions of the
central and southern High Plains.

....20Z Update...
No major changes have been made to the outlook. Convection
developing near the higher terrain of CO (and adjacent portions of
NM/WY) is expected to intensify later this afternoon and evening, as
it moves eastward into an increasingly unstable environment. These
storms are expected to pose a threat of severe gusts (potentially in
excess of 75 mph) and isolated hail. See the previous discussion
below for more information regarding the outlook reasoning. See MCD
897 for more information regarding the short-term threat across the
High Plains, and MCD 898 for more information regarding the
short-term threat across parts of the lower MO River Valley.

...Dean.. 05/30/2023

..PREV DISCUSSION... /ISSUED 1117 AM CDT Tue May 30 2023/

....Central High Plains...
Morning model guidance shows a weak mid-level shortwave trough
lifting northeastward through the four-corners region.  Broad but
weak large scale ascent ahead of this trough is resulting in a large
patch of mid/high clouds moving across the central Rockies.  This
area of moisture will overspread the high plains of eastern
CO/northeast NM by mid-afternoon.  Full sunshine will lead to a very
deep mixed layer with inverted-v thermodynamic profiles, along with
marginal CAPE.  This should support scattered high-based showers and
thunderstorms capable of dry microburst activity.

As this convection and associated outflow boundaries spread eastward
during the late afternoon and early evening, they will interact with
a moist and very unstable air mass (MLCAPE over 3000 J/kg) from
western NE into far eastern CO, western KS, and the TX/OK
Panhandles.  Rapid intensification of storms will lead to more
widespread and intense wind gusts during the evening, along with a
few cells capable of large hail.  Severe storms will persist for a
few hours after dark, before diurnal cooling/decoupling weakens the
threat.  Given the high degree of agreement between 12z CAM
solutions, will introduce a narrow ENH where greatest concern for
damaging winds is apparent.

$$
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