BLOG: Analysis of Storm Threat Today+Look at Long Range

Things got a little bumpy around the Valley last night as some storms were strong enough to produce small hail and hefty winds. The strongest storm was probably the cell that ripped through Columbiana County around 9:30-10:15pm. Doppler-radar estimated wind speeds were around 60 mph around Calcutta; the bright green area on the right is that ball of wind.  columstorm

With multiple storms rolling over some areas several times, rainfall amounts were pretty high Tuesday. Here’s the radar estimated totals (notice the most concentrated area of 1″+ is in the southern half of Columbiana County): totals

For this reason, the National Weather Service has issued a Flash Flood Watch for this afternoon and evening for Columbiana County. Flash flood guidance suggests that 1.5-2″ of rain in a 3 hour period would lead to widespread flash flooding. While that much rain is not necessarily LIKELY….it is possible.  ffgNotice the amount of rain needed to cause flash flooding is even lower around Pittsburgh.

So, let’s talk about how today will play out. We still have a warm, humid airmass around, but there is a weak cool front just to our north. The temperature change is not real noticeable on the other side of the front…but the dewpoint change is. Here’s the dewpoints and the location of the front at 10am: dew

That front is going to slowly push south today. I think all of NE Ohio and western Pennsylvania can see a shower or thunderstorm through mid afternoon. Look at the CAPE (Convective Available Potential Energy) early this afternoon: cape2pPretty unstable from Youngstown south. But then look at 5pm: cape5pDrier, more stable air will be working in from the north. The latest HRRR model “simulated” radar product shows the threat for wet weather shifting south this afternoon. 2pm: 2pm

5pm: 5pm

So, if you need to mow or do anything else outdoors…I suspect that most places north of 224 will be high and dry after say 3:00 or so. The threat for damaging winds is minimal with any storms today, but it can’t be ruled out. The Storm Prediction Center has a 5-15% chance in the yellow area: day1wind

That slow moving front will clear the state by Thursday and Friday and things are looking great. The humidity will come down and the sun will be out. The jet stream looks like this today: jetnowThere’s a cutoff low in the lower Mississippi Valley that will weaken and get absorbed in the flow soon. That ridge of high pressure will build east for the weekend: 500weekendIt will be cool on both coasts with troughs overhead….but for us….AWESOME.

The medium range is looking pretty warm. The latest GFS Ensemble model keeps us generally above average into the 2nd week of June: gefs

June may shape up to be somewhat wetter than average across the region, if the Climate Forecast System has the right idea: june

Thanks for reading and have a good Wednesday!