SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Models are coming into better agreement for severe weather
potential on Sunday.
Strong low pressure will move northeast from the lower Ohio
Valley to northwest Ohio by late Sunday afternoon. Widespread
showers and embedded thunderstorms will be ongoing during the
morning hours as a strong, moist LLJ pivots east. As this
occurs, a warm front will being to lift north into the region,
and then move as far northwest as our far northwest CWFA where
the low will eventually track toward. The airmass is expected to
destabilize fairly quickly in the warm sector behind the initial
large band of showers and embedded thunderstorms Sunday
afternoon. This is indicated nicely on the 12Z NAM model
sounding forecast at 20Z for KILN. Deep layer shear will be in
place, 70-90 knots between 0-6 km, and even 50-60 knots between
0-3 km. Hodographs indicate nice clockwise turning of winds with
height in part to the proximity of the nearby surface low.
MLCAPEs of ~ 1000 J/kg is also forecast. These parameters will
set the stage for showers and thunderstorms as they develop
along and ahead of a trailing cold front as it moves from west
to east through our region Sunday afternoon into early Sunday
evening. High resolution models indicate convective
lines/bowing segments, and perhaps some discrete supercells.
This will result in damaging winds being the main severe
weather threat. However, a few tornadoes may occur given the
setup (discrete supercells), especially along and southeast of
I-71 where SRH values are the highest. In addition, isolated
large hail may occur, given rotating updrafts, and locally heavy
rain/localized flash flooding may result after the morning
widespread rainfall of 1 to 1.5 inches (making for moist soils).
These threats have been placed in the latest HWO. Highs on
Sunday will range from the mid 50s far northwest, to perhaps the
lower to mid 70s across the southeast. It will also become
breezy to locally windy on the synoptic scale with wind gusts
between 25 and 35 mph in the warm sector.
For Sunday night, as the low continues on its track northeast
toward New England, the cold front will move east of our area
during the early evening, bring the end to the severe weather
threat. CAA and a few/scattered showers will be possible during
the evening, with pcpn tapering off from west to east
overnight. Post-frontal stratocumulus will remain. Winds will be
gusty between 25 and 35 mph. Temperatures will cool off with
lows bottoming out from the lower 30s northwest to the upper 30s