Archives — Chief Meteorologist Eric Wilhelm's Blog

**Click on pictures to enlarge**Good Monday everyone,Showers and some heavy thunderstorms rumbled through the Valley on Sunday, dropping some heavy rain and causing a few problems with flash flooding. Gusty winds caused some minor damage here and there. But of course the main story is the *possible* tornado that occurred near a Sheetz located on South Hermitage Road. So did a tornado occur here? The answer to that question, as of this writing, is still "maybe". The National Weather Service in Pittsburgh may do a damage survey to assess whether it was just thunderstorm winds or a weak (likely EF0) tornado). In the meantime, we can take a look at some of the radar data from mid-afternoon Sunday to do our own "forensic" analysis.Here's the radar at 3:56pm:Just looks like a pretty standard issue squall line with heavy rain. BUT, with modern "dual pol" doppler radar, we can see so much more now. One of the most important tools we have at our disposal now is the ability to look at the wind field within a thunderstorm to see how fast the wind is blowing and what direction it is blowing in. Most of you are familiar with what a "tornado vortex signature" looks like on radar. A tight "couplet" of green (wind blowing toward the radar) and red (wind blowing away from the radar). Looks like this:At 3:56 Sunday, here's what the doppler wind velocity data looked like:Not much of a tornado signature right? There is no bright green next to bright red. But there IS some weak rotation being detected. Weak rotation does not often present itself with that nice, vivid, obvious green/red couplet. We can see the rotation by looking at a 3D view of the storm and calling up the "normalized rotation" product:The blue color shows some weak rotation from near the surface to several thousand feet high in the storm.At 4:01pm, the radar looked like this:The velocity product continued to show just a hint of rotation but mostly just strong winds.By looking at the "normalized rotation: product, you can again see some indication that there was some weak rotation. So, what do I think? I think it is quite possible that a weak, likely EF0 tornado touched down for a few minutes. There is enough radar evidence to support that. We will see if the NWS has a look, and if so....what they can determine from the damage in the area.A WORD ABOUT PICTURES ON SOCIAL MEDIA: i want to thank everyone for sending in the great pictures of yesterday's storms and damage on social media. But as always in these situations, I implore you to BE CAREFUL with what you share. View everything with skepticism. There are plenty of people out there who trade in bad information/fake pictures, etc.This picture made the rounds yesterday:This was taken in SHARON, around 3:00pm, a full hour before the Hermitage/Sheetz storm. The two are not related. A cool picture though. Is it a funnel cloud? Probably not. Just an interesting swirl! Not all funny looking or "swirly" clouds are funnel clouds.This picture took the cake for "most obvious fake". Allegedly from the May 31, 1985 outbreak:This is not, not NOT! a real picture. It's a photoshop job. The person who made it admitted to it and I banned him from my page. Folks it is EASYYYYY to determine if a picture is fake these days. If it looks too good to be true, too amazing, it probably is.Google Image Search and FotoForensics are our friends.OK, ON TO THE MAY REVIEW AND JUNE/SUMMER PREVIEW. May is in the books! Locally, it ended up being a very warm month compared to the average. Here's the final temperature and precipitation numbers:So we finished a little over 6 degrees above average. Pretty impressive and good for a Top 10 finish on the list of warmest Mays on record in Youngstown:Precipitation-wise, May was fickle. We were well below average for much of the month but certainly ground was made up...and then some...over the last several days. So we actually finished the month above average.The rest of the region did not fare as well...notice all the dryness in central and southern Ohio, as well as Pennsylvania.What an amazingly rainy May in the southern Plains and the Rockies:OK so what does June have in store? The pattern that evolved in May is likely to persist. That means, odds favor June being above average temperatures-wise and perhaps in the rainfall department as well. Here's the laest CFS (Climate Forecast System) outlook for June. Temperatures first:Rainfall:Notice all the wetter-than-average areas east of the Rockies.SUMMER:Meteorological Summer is upon us and the question on many people's minds is: will it be "better' than last Summer? Most perceive the Summer of 2014 as quite cool. This is mostly due to the very cool stretch of weather we had in July. But as a whole, Summer 2014 was only SLIGHTLY cooler than average.We have had 2 near or slightly cooler than average Summers in a row after some hot ones:I do think that this Summer will be somewhat warmer than the last couple, but not by much. Overall, I suspect it will end up being pretty close to average. Here's what the latest runs of the CFS have been showing for June/July/August:Warm on the West Coast, warm in the SE, cool in the southern Plains. Not much of a signal around the Ohio Valley/Great Lakes. This seems reasonable to me, given the El Nino, along with water temperatures off the West Coast of the US and over the western Atlantic.As for as precipitation goes:The CFS suggests that we may end up above average. But warm-season precipitation totals are notoriously hard to predict because thunderstorms can skew them tremendously. Some years a very dry Summer has 5 days with intense, high precipitation thunderstorms and so the rainfall numbers don't "look" all that low at first glance.Another reason Summer 2014 is perceived as a cool one: lack of extreme heat. There were NO 90 degree days last Summer. In Youngstown, we average 8-9 90+ days per Summer. 90+ days each Summer since the 30s:This year, I suspect we will see a few, but may not see the average of 8-9. I doubt we have an above-average season.Thanks for reading!Eric

Happy Friday! Been a while since I have done a blog post but the weather hasn't been all that "interesting" lately. The warmth remains the big story. The first week of May has featured above average temperatures every single day. How does this stack up against other warm starts to May? Somewhat surprisingly, we have had much warmer starts to the month. Even some recent years on this list:I'll talk about the longer-range outlook later in the post, but if you've watched my videos and TV forecasts you know I am expecting the warmer-than-average weather to continue for much of the month.In the near term, it's Mother's Day weekend and lots of people will be outdoors. Today's threat of rain is very low, in the 10-20% chance range this afternoon. It will be so warm (and somewhat humid) that the atmosphere might try to pop a couple of showers.Instability will be pretty modest today so thunder isn't very likely in any of these stray showers. CAPE, or Convective Available Potential Energy is one of the ways we measure instability in the lower atmosphere. CAPE values today are pretty low:On Saturday, the atmosphere will be somewhat more unstable. This might lead to more numerous showers/storms in the afternoon but the coverage will still not be very high. Very very "hit or miss". Most will miss.Sunday's weather map will be a wild one with strong low pressure across the Plains, severe weather possible again in the Midwest and Mississippi Valley, SNOW in the northern Plains and Subtropical Storm Ana still annoying the Carolinas.Here at home, expect another very steamy day. Chance for a pop-up shower or storm is there once again in the afternoon but the coverage will still be pretty low. Keep those outdoor plans.A cold front will arrive Monday night. Behind that front, it WILL cool down and turn less humid.But for how long? Not long! Check out how quickly the warmth is likely to return:Climate models have been leaning toward a June that will likely be closer to average than this very warm May. Notice the lack of any strong warm or cool signals for us:What about the Summer as a whole? If the current modeling is on the right track...."ho hum". No strong signals for temperatures and precipitation at this point. Might end up being very "typical" in both departments.Thanks for reading and have a good weekend!Eric