563
ACUS01 KWNS 160548
SWODY1
SPC AC 160547

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1247 AM CDT Tue Jul 16 2024

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE OHIO VALLEY AND NORTHEAST AND OVER THE CENTRAL PLAINS...

...SUMMARY...
Strong to severe thunderstorms are possible from the central Plains
across the Mid Mississippi and Ohio Valleys into the Northeast later
today. Greater severe-thunderstorm potential is anticipated across
the central Plains vicinity, and from the Upper Ohio Valley into the
Northeast.

...Upper Ohio Valley to the Northeast...

Latest model guidance continues to suggest a seasonally strong upper
trough will dig southeast across MB/ON into the Great Lakes later
today. This evolution will force southern extent of stronger
mid-high-level flow to sag south across the mid MS and OH Valley
region, as well as New England. Of particular note early this
morning, a well-defined MCS has evolved over the Midwest with the
leading edge of this complex arcing from southern lower MI-central
IN-central IL. Remnants of this MCS are expected to serve as the
focus for renewed robust thunderstorm development early this
afternoon. Current speed/movement suggests strong/severe
thunderstorm development will occur over the upper OH Valley as
temperatures warm into the mid 80s. MCV is currently located over
southern Lake MI and this feature will track across extreme southern
ON which should encourage upscale convective growth during the
afternoon. Damaging winds are the primary concern with this
convection.

Somewhat removed from this feature, very warm surface temperatures
are expected across northern VA, the Delmarva into NJ. Latest
guidance suggests convective temperatures in the upper 90s will be
breached by 22z. PW values are fairly high despite the warm
temperatures, and severe downbursts could be noted with storms that
evolve along this corridor.

...Central Plains...

Northwesterly mid-level flow is forecast to strengthen a bit across
the central High Plains as the Great Lakes trough becomes a dominant
feature in the eastern US. Latest model guidance suggests a surface
front will settle across southern KS, arcing into southeast CO by
late afternoon. Strong boundary-layer heating along/south of this
boundary will allow temperatures to soar above 100F and any CINH
will easily be removed. High-based convection that evolves near this
boundary may efficiently generate strong downdrafts.

Upslope flow across eastern CO favors convection generating off the
higher terrain which should congeal downstream over the Plains
during the evening. This activity would then propagate southeast
toward northwest OK during the overnight hours.

Models also continue to generate robust convection ahead of a weak
short-wave trough digging toward NE by late afternoon. A weak
surface low is forecast to develop in response to the digging short
wave, and a small corridor of focused low-level convergence is
expected to aid this development.

...Southern MO to southern IN...

Considerable uncertainty exists regarding convective evolution
today. While there is confidence in scattered convection developing
along a pronounced frontal zone at some point, most model guidance
is notably inconsistent due to varying influences from early-day
thunderstorms and their effect on air mass destabilization. Some
consideration was given to increasing severe probabilities along
this corridor, but confidence in placement/timing of strongest
convection does not warrant this at this time.

..Darrow/Marsh.. 07/16/2024

$$