Valid 051200Z – 061200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Thunderstorms are possible late Thursday night and early Friday
morning, mainly across Arkansas. There does not appear to be an
appreciable risk of severe weather with this activity.
The upper-level trough across the eastern quarter of the CONUS will
move offshore today. Across the West, large-scale ridging will
develop downstream of an upper-level trough approaching the West
Coast. The main synoptic feature of interest during this period will
be a shortwave trough that will progress from the Four Corners into
Arkansas by Friday morning.
…Eastern Oklahoma into the Ark-La-Miss…
Modest mid-level ascent from the low-amplitude shortwave and
warm/moist advection at low levels will promote the development of
isolated to widely scattered thunderstorms, primarily after 06Z.
Forecast soundings indicate this activity will be elevated in
nature. There exists some uncertainty with regard to low-level
moisture return. With the shortwave trough slowing in recent model
runs, greater moisture may be able to progress farther north than
forecast. Even so, MUCAPE on the order of 250-500 J/kg appears most
probable. Weak effective shear and minimal buoyancy will limit storm
intensity, though modest mid-level lapse rates may support
sub-severe hail in the most intense storms.