CINCINNATI – Tuesday is a 9 First Warning Weather Alert Day due to the potential of strong and severe storms during the morning and again in the afternoon.
A low-pressure system, which is impacting the Central Plains Monday, will continue northeast through the United States overnight into Tuesday. This will push straight into the northwest of the Ohio River Valley by Tuesday morning.
The Storm Prediction Center has highlighted much of the Tri-State in its outlook for severe weather Tuesday. We are included in a Slight risk (Level 2 of 5) for storms. Don’t let that “lessened” category fool you, we still have the potential for severe storms but there are few variables that are in question. Let’s get into it.
We’ll have two rounds of storms on Tuesday. For the morning, the main threat is the straight-line damaging winds of 60 mph, however, we can’t rule out the embedded tornado if we get developing a rotation within the storms. That however looks less likely in the morning. Severe wind gusts of 60+ mph, however, we have the potential for large hail, of 1 inch in diameter or greater, as well as few isolated tornadoes. These are more likely if supercell storms develop. The bigger threats to these will be into Ohio & Northern Kentucky.
Heavy rain and flooding is also a threat, but that remains low. Most areas will receive 1 to 2 inches of rain, which would increase a flash flood threat.
As mentioned before, we will have two rounds of potential severe weather on Tuesday. That first wave will be a big concern for the morning rush. A warm front will push in from the storms will push in after 3 am bringing with it a wave of steady rain and storms. It is along this front where we have the better threat at spin, which could create that tornado threat. It is more likely that we will see storms push into the Tri-State around 5 am before exiting by 10 am If these linger later in the afternoon, that will greatly affect our afternoon threat.
After the warm front moves we will be in the “warm sector” of the storm which will mean rising temperatures and maybe even sunshine.
Our window for round 2 will open around 3 pm Tuesday as a cold front starts in central Indiana. Storms will initially start out as individual cells before likely merging into a line of storms, squall-line, as it moves towards the east. It is at this time, where storms are individualized, that our tornado threat looks greatest.
Storms will last through the evening commute before moving out of our area around 9 pm Shortly thereafter we will see the passage of the cold front, which will cut off any threat for storms.
WHAT WE NEED TO WATCH:
When forecasting storms we have four main factors that really determine severe weather. To use the acronym of SLIM This covers Shear, Lift, Instability, & Moisture. Shear is a measure of the spin in the atmosphere, which you need for storms to turn and strengthen. Lift is what helps these storms develop with an upward motion to push the higher storms into the atmosphere. Instability measures the energy in the atmosphere for storms to feed off of. The higher those level get, the stronger storms are able to become. Lastly, Moisture. You can’t have storms without moisture, but the higher the levels, the better the threat for strong storms & tornadoes.
The biggest question for Tuesday afternoon will be whether or not we are able to destabilize enough after the morning rounds of showers and storms and if so, there will be enough shear / twist in the atmosphere at the same time.
If the morning rain lasts longer than expected, or we do not see much warming through the middle of the day, that will limit our daytime heating which drastically could drop our energy levels. A benchmark value for energy is around 1,000 J / KG and it looks like those morning storms are gone by 10 am The warmer we get on Tuesday; the more energy will be available.
Another question is whether or not we have enough moisture available for the storms. Dewpoints of 65 ° F and greater are usually the target for severe storm potential. If we see the impact of higher moisture, then our instability will also increase which would amplify our threat for storms. Right now, the better variables look to be across Southwest Ohio and Northern Kentucky. Either way, the threat is there and needs to be monitored.
As always, make sure to stay weather alert Tuesday. We will have coverage for you on the Roku, Amazon Fire, and Apple TV devices. Keep checking for the latest updates as we get closer and closer.
9 First Warning Weather 24/7 Livestream