456
ACUS01 KWNS 191244
SWODY1
SPC AC 191242

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Wed Jun 19 2024

Valid 191300Z - 201200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN HIGH PLAINS...SOUTH/SOUTHEAST TEXAS...AND MIDWEST TO NEW
ENGLAND...

...SUMMARY...
Locally strong wind gusts and hail may occur with storms over the
southern High Plains, with a couple of strong gusts also possible
across parts of the Midwest and from the Lower Great Lakes into New
England. A brief tornado or two may occur across south Texas through
tonight.

...Synopsis...
Dominant East Coast upper ridge is forecast to build west into the
Middle Mississippi Valley later today as the primary belt of
westerlies retreats north of the international border. This westward
expansion will encourage the tropical system over the western Gulf
basin to move into northeast Mexico, considerably south of the Rio
Grande Valley.

...Southern High Plains...
As convection persists while generally diminishing in overall
intensity across the Oklahoma/Texas Panhandles and northwest
Oklahoma this morning, outflows will contribute to additional
moistening with westward extend across far west/northwest Texas into
eastern New Mexico. This is where potentially severe thunderstorm
development is expected around mid/late afternoon across the Raton
Mesa vicinity southward across east-central/southeast New Mexico.
Instances of large hail and severe-caliber wind gusts will be
possible.

...Lower Great Lakes to northern New England...
While upper ridging will dominate this region, scattered convection
will once again develop from portions of the Ohio Valley
northeastward into New England, as surface temperatures warm through
the mid 80s to near 90 F. Convective temperatures will be breached
and thunderstorms should develop within a seasonally moist
environment with PW values in excess of 1.75 inches. Gusty winds are
the primary concern with this convection occurring in a weakly
sheared environment.

...South/southeast Texas...
Low-level shear will increase especially this afternoon into tonight
along the Texas Coast and inland across south Texas, along the
northern fringe of the western Gulf basin tropical system. Reference
NHC for the latest details on Potential Tropical Cyclone One, as
this feature may evolve into a tropical cyclone before it moves
inland south of the lower Rio Grande Valley. While this system will
remain at low latitudes, 850mb flow is expected to increase across
south Texas such that sustained updrafts will likely rotate. High PW
and strong low-level shear favors some risk for a tornado or two.

...Northern Missouri/eastern Iowa to southern Wisconsin...
To the east-northeast of lingering early morning convection across
northeast Kansas/northwest Missouri, cloud cover should generally
diminish today near the outflow augmented
southwest/northeast-oriented synoptic front across the region.
Potentially aided by an MCV, thunderstorms should redevelop and
intensify this afternoon as the boundary layer destabilizes, with as
much as 30 kt of effective shear maximized immediately near the
synoptic front. Isolated instances of localized wind damage could
occur.

..Guyer/Leitman.. 06/19/2024

$$