Watch boxes are out in MO and ILL this morning. SPC has slight and marginal risks up now for all posters. Best threat is still north of Cincinnati IMO, but if the HRRR is right, we all stand a chance at that line coming thru this afternoon.
https://www.spc.noaa.gov/products/outlook/day1otlk.html
The HRRR has been very consistent too. To my knowledge, the NAM still isn't showing anything until tonight. So I guess the HRRR is really going to score here or it will look silly. We'll know by lunch time. The boys had this to say:
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Another warm day is expected ahead of low pressure and a cold
front that are forecast to cross the region on Friday.
For the morning hours, low level moist ascent at the nose of a
925 mb-850 mb low level jet will bring the threat of showers and
thunderstorms, mainly to west central Ohio. These storms will
be elevated in nature, so only some small hail is expected.
For this afternoon, high resolution convective allowing models
indicate that a linear convective line of showers and
thunderstorms will traverse the region, likely weakening as it
makes its way into our eastern zones. Some surface based
instability is expected with this line, but the severe threat
appears to be marginal given lower level CAPE values. In any
case, this will have to be watched, and certainly some strong
storms may still occur.
The greatest potential for severe weather is slated for late
this afternoon into this evening. As low pressure and a cold
front approach our region from the west. Low level moisture
convergence will increase across northern Indiana and northwest
Ohio. This will likely result in the development of
thunderstorms, some of which may be supercellular given
substantial deep layered shear (both 0-3 km and 0-6 km), turning
hodographs, ample 0-1 km SRHs, and SBCAPES approaching 1000
J/kg. Hence, SPC has outlooked parts of east central Indiana,
the Whitewater/Miami Valleys, west central Ohio and parts of
central Ohio in a slight risk for severe storms. All severe
weather threats will be on the table in these areas: damaging
winds, large hail, and isolated tornadoes. This convection will
likely congeal into a more linear structure as it moves
east/southeast farther into our forecast area later in the
evening and overnight hours. Some storms will have the potential
to produce heavy rainfall, and with the mid level flow in a
zonal orientation, some training of storms will be possible,
especially along and north of I-70. All of these threats have
been placed in the current HWO. For points farther to the east
and south, on the periphery of the slight risk, a marginal risk
for severe storms exists. The great potential for severe storms
in the slight risk area will be 5 pm to midnight, and 7 pm to
midnight in the marginal risk area. The severe weather threat
will diminish substantially after midnight has SBCAPES wane.
In the warm sector, highs will range from the upper 60s
northwest to the lower to mid 70s elsewhere.
