289
ACUS03 KWNS 270732
SWODY3
SPC AC 270731

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0231 AM CDT Mon May 27 2024

Valid 291200Z - 301200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY
AFTERNOON AND EVENING ACROSS PARTS OF EASTERN MONTANA...WYOMING AND
COLORADO INTO PARTS OF THE WESTERN DAKOTAS...NEBRASKA AND
KANSAS...PARTS OF SOUTHWESTERN TEXAS AND ADJACENT SOUTHEASTERN NEW
MEXICO...

...SUMMARY...
Widely scattered strong storms posing at least some risk for severe
wind and hail are possible across the High Plains Wednesday
afternoon and evening.

...Synopsis...
Stronger westerlies, with at least a couple of modestly amplified
embedded waves, are forecast to persist across the northern
mid-latitudes of the Pacific into western North America through this
period.  Near the leading edge of this regime, this is forecast to
include larger-scale mid-level troughing which appears likely to
remain progressive across the western Canadian Prairies and northern
U.S. Rockies, even as downstream flow trends a bit more amplified
and less progressive.  To the east of this trough, models suggest
that an anticyclonic circulation may at least attempt to evolve
within larger-scale ridging across southern Manitoba into adjacent
portions of northwestern Ontario.  The progression of the upstream
trough may ultimately preclude the evolution of a closed
circulation, but positively tilted amplified mid-level troughing
downstream (inland of the Atlantic coast) is forecast to move little
Wednesday through Wednesday night.

In the southern mid- and subtropical latitudes, ridging, initially
centered over central Mexico before retrograding into the Pacific to
the south of Baja, may remain suppressed as low-amplitude mid/upper
troughing progresses inland across California and northern Baja into
the Southwest.

Beneath this regime, models indicate that a notable reinforcing cold
front will advance into the Southeast, while stalling and weakening
across the eastern Great Plains.  It appears that a convectively
augmented front may reach the Texas Gulf coast and lower Rio Grande
Valley through Texas Big Bend vicinity by early Wednesday, before
stalling and weakening.

Boundary-layer moistening may occur within deepening surface
troughing across the High Plains, but particularly to the north of
the Front Range, it appears that this will remain rather modest for
the time of year.

...Lee of northern Rockies and Front Range...
Through peak daytime heating and into Wednesday evening, deep-layer
shear downstream of the inland progressing trough is forecast to
remain weak across the High Plains.  However, even with limited
boundary-layer moisture, steep lapse rates may support mixed-layer
CAPE on the order of 1000-1500+ J/kg.  This may be sufficient to
support widely scattered storms posing at least some risk for severe
wind and hail.  Storms initiating off the higher terrain, and as
convective temperatures are reached near the lee surface trough, may
tend to consolidate into widely scattered clusters, augmented by
strengthening southerly 850 mb flow (in excess of 30 kt), before
weakening later Wednesday evening.

...Southwest Texas...
Models suggest that moisture and lapse rates across the Pecos Valley
into the Davis Mountains vicinity will remain supportive of moderate
to large CAPE with heating Wednesday.  Beneath moderately strong and
difluent westerly mid/upper flow, downstream of the low-amplitude
wave advancing into the Southwest, orographic forcing may support
the development of one or two supercell storms during the afternoon
and evening.

..Kerr.. 05/27/2024

$$