BLOG: Why No Warning? Plus: a Look at Tornado History in Valley and a Look Ahead

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This evening I wanted to take some time to discuss the tornadoes in our viewing area and what made this situation challenging for meteorologists at the National Weather Service and on television.As you probably know by now, the tornado in Mahoning County was not preceded by a Tornado Warning from the National Weather Service. Many have been upset by this and that in understandable. Particularly if your property was damaged. While ideally every tornado is warned for ahead of time, the science is just not there yet. In fact, in the United States, about 70% of all confirmed tornadoes occur in an active tornado-warned area. That means that 3 out of every 10 occur where there is no official warning. This success rate is about DOUBLE what it was 30 years ago, but of course, still not good enough.Many tornadoes that are not warned are ones like we had near Canfield. They drop quickly and then lift quickly...leaving behind little evidence on Doppler Radar that a tornado is occurring. We rely heavily on Doppler Radar to detect tornadoes. It DOES have limitations through.Canfield is roughly 66 miles as the crow flies from the National Weather Service radar, which is located southwest of Cleveland. distancebeamBecause of the curvature of the Earth, the height of the radar beam increases with distance away from the radar site. 563px-Radar-hauteur-en.svgBy the time the beam is over Canfield, it is about 5,000 feet in the air. This can make rotation in the lowest levels of the atmosphere hard to detect. Here is the wind velocity image from right about the time the tornado touched down (2:12pm): canfieldvelocNotice, there is a "spike" in the wind velocity data being detected at exactly the spot the tornado touched down. BUT, no rotation is detected. We would have seen some greenish colors near that location had rotation been detected. Compare that image to the tornado in Mercer County: tvsA NICE "couplet" of green (wind blowing toward the radar) and red/yellow (wind blowing away from the radar). Clear rotation and an easy Tornado Warning for the NWS (in Pittsburgh) to issue.Despite the lack of a rotation "signature" on the Canfield tornado, at 2:12pm, there was an interesting signature on the "regular" radar. A hook shape was evident for only ONE scan: hookThis caught my attention during our online streaming coverage, but with no clear rotation in the velocity data I did not immediately declare that this was likely a tornado and people should seek shelter. In hindsight I probably should have played it up more, but this was a tough call to make on the fly.I thought it may be interesting to take a look at the recent history of tornadoes in Mahoning and Mercer counties. I showed these graphics on the air this evening showing the most recent twisters in the counties: MahoningTorMercerTorA more thorough list of tornadoes, going back to 1950. These tables include the location, the damage caused, the rating on the Fujita scale, among other things.Mahoning: mah1Mercer: mercerInteresting to note how many more tornadoes there have been in Mercer County. I am not sure why this is, other than it being a larger county.There have been ZERO F4/F5 tornadoes in Mahoning County since 1950. The strongest on record was an F3 twister shown here: 1956The longest-lived tornado I could find was this one (F2) from 1963 that was on the ground for 15 miles and paralleled Rt 224: 1963 How about a quick look at the FUTURE weather? After a warm weekend, next week is looking quite cool for July, especially during the middle of the week. Check out the upper-air pattern: 500Looks like it did in the Winter! Deep trough over the Great Lakes. That's actually part of the Polar Vortex! Remember, the Polar Vortex exists year-round (despite the hysteria in the media during the Winter, much of implying this was some sort of new thing). This will result in a big area of below-average temperatures: departSince it is July and not January, that means temperatures will not be "cold" but we will see at least a few days with highs closer to 70 than 80. 90 is certainly out of the question. We have not had a 90 degree reading yet this year. How unusual is that? Not all that unusual. Here's a list of years with ZERO 90 degree days for the entire year. no90sannualHere's the list of Julys with no 90+ days; no90sjulyThanks for reading!Eric 

BLOG: Heavy Storms, Possible Severe Weather

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The holiday weekend is over and so is the tranquil weather! We have a busy couple of days coming up so let's get right to it.As you head out today, you will notice it's more humid than it has been over the last couple of days. Here's this morning's weather map: nowA warm front moved through last night and dewpoints have come up significantly. Check out how high the dewpoints are in parts of the region, especially to our west: dewThat soupy air mass is pushing into the region ahead of a weak cool front. As that cool front pushes east, it will help lift this moist, unstable air mass and some thunderstorms are likely to get going this afternoon. Here is the 2pm simulated radar off of the HRRR model: 2pmThe threat for thunderstorms will be with us through the end of the afternoon/early evening. It is important to note that MOST of these storms will NOT be severe. Sure, they will have plenty of lightning and some tropical downpours. But most will not produce hail 1" or larger or damaging winds. BUT, the potential is there for a COUPLE of them to reach that threshold.The Storm Prediction Center has the entire region in the enhanced risk zone today: DAY1The odds of a damaging wind gust within 25 miles of any location are about 15% today: WINDSame with large hail: HAILThe tornado threat, while not ZERO, is very low. SPC has us in the 2% area. TORUnfortunately this is not the only day we have a severe weather threat this week. Tomorrow could be quite busy as well! Taking a look at the mid levels of the atmosphere (about 500 millibars or 18,000 feet), notice today we have our (fairly weak) disturbance moving through the Midwest and Great Lakes....and a stronger system getting set to exit the northern Rockies: 500todayBy tomorrow, that system will be pushing through the Great Lakes and causing more showers and thunderstorms: 500tueOnce again we are in the SPC enhanced risk zone, and for good reason. Any storms tomorrow afternoon could pack quite a punch. day2More details on tomorrow's weather once we get through today!Thanks for reading.Eric

Quick June Review+Severe Weather Threat Today

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Good morning! After a couple of weeks of travel I am back today; could I ease back in with a quiet weather day?? Nooooooo. We will talk about the severe weather threat in just a second. First, a quick June review. In the temperature department, it was a warmer than average month. 2.5 degrees above average in fact.Would you believe that after the FRIGID start to 2014, June was our 3rd consecutive above average month?? Since April 1, Youngstown is 1.7 degrees above average. Not a bad turnaround. aprjuneWith several rounds of thunderstorms, June was a very wet month in much of the region.   totalsMost of these are rain gauges that have the capability of uploading their data to the internet.OK, on to the severe weather threat today. Thankfully the threat for severe weather across northeast Ohio and western Pennsylvania will not be as high as it was last night to our west. Check out these storms around 11:30pm as the rolled east of Chicago into northern Indiana. On the right...Doppler Radar estimated wind speeds of 70-100 moph! lastnightNot surprisingly, there was lots of wind damage.While we do not expect a repeat of that, conditions are favorable for some nasty storms to form this afternoon. It is a VERY juicy airmass overhead. This morning's dewpoints: dewIt feels like Orlando.We have a potent trough of low pressure moving across the Upper Midwest today; it's causing uplift of that warm, very humid air: 500How unstable, or buoyant, will the air mas be this afternoon? Here's the latest hi-res model CAPE values (a measure of instability): 3pcapeThose are some pretty high values across the region.  So to review, we have the moisture in place, the air is free to rise and we have a "trigger" to help the air to lift. So what's gonna happen??I suspect the most active period is roughly from 3/4pm to 8/9pm. A quick tour of the latest HRRR model's "simulated" radar:3pm: 34pm: 45pm: 56pm: 67pm: 7Notice a couple of things. 1) The model suggests that the threat is highest south of I-80 or perhaps even 224. 2) It winds things down quickly well before sunset.  These are trends that we will be watching all midday/afternoon. If several consecutive model runs show these ideas, our confidence will increase.The Storm Prediction Center has the odds of a tornado at 2% (within 25 miles of any one spot): torHail and damaging wind ods are the same, 15% for the WFMJ viewing area: hailThese odds may need to be lowered in the northern part of our viewing area if these early morning model trends continue.Jess has you covered on 21 News at noon and I will be on tonight at 6 with the latest. As always, I will be posting all kinds of updates on Facebook and Twitter. Thanks for reading!Eric  

BLOG: Severe Weather Threat Today/Tonight

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Will try and keep this brief as the American Meteorological Society Conference on Broadcast Meteorology is getting underway this morning in beautiful, but COLD Lake Tahoe, CA.The atmosphere is going to be primed to produce some heavy thunderstorms this afternoon and tonight. While the timing is not set in stone as I write this, we just have to be on our toes.How nasty things get this afternoon will probably depend on what happens with this line of storms west of Chicago (at 10:25 Eastern): 1020IF that holds together, it can be a problem for NE Ohio and western PA this afternoon...but I am not sure yet if it will. IF it fizzles, activity will likely be quite spotty...but any spotty storm could be quite nasty.The Storm Prediction Center odds for damaging winds is up to 30% (within 25 miles of any location) for much of the region this afternoon and tonight. Damaging winds and flooding are EASILY the 2 biggest concerns. windThat said, there can be hail as well. Odds of large hail within 25 miles of any location are about 15%: hailAn isolated tornado cannot be ruled out in any storm, but the odds are quite low, 2%: torIF this afternoon ends up not being particularly active, tonight could bring the most trouble. Latest hi-res models want to bring a nasty, bowing line of storms into Ohio after sunset. Here's the 10pm simulated radar: 10pmRemember, this is just a MODEL and may not have the right timing/ideas. Certainly our confidence in storm timing and impacts will increase throughout the day today. Thanks for reading!Eric

BLOG: Today's Severe Weather Threat

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After a benign start to the work week, the threat for some heavy, gusty storms returns to the Mahoning and Shenango Valleys today. The risk of storms will ramp up by mid to late afternoon. Things are quiet enough this morning. The current surface map (at 9am) shows low pressure to our west and a soupy air mass around the region. Check out the dewpoints: dewpress It's also fairly cloudy. And this is a GOOD thing. The more clouds, the less unstable the atmosphere will become. 9am visible satellite: vis Where the atmosphere was unstable enough, things got very bumpy yesterday with a lot of reports of wind damage from southern Ohio down into the Southeast: reportsNotice there may have been a weak tornado or two in southwest Indiana.Today, the threat shifts north and east as this system tracks in that direction. Not only will the atmosphere be moist enough to support big storms, but we will be in a favorable region for air parcels to lift. This is the 500 millibar chart, a look at the atmosphere at about 18,000 feet. Vorticity, or spin in the atmosphere is shown, along with the position of troughs and ridges. The Valley will be on the east side of a trough of low pressure; this is a zone that favors lift. 500 Here is the Storm Prediction Center outlook for today/tonight....the yellow area is the "enhanced" risk area: day1Let's talk about what "type" of severe weather is most likely. Remember, the definition of a severe thunderstorm is: a storm that produces either hail 1" in diameter or higher or winds of 58 mph or greater.  Here are the odds of a tornado within 25 miles of any location: torOdds are quite low in our area and higher to the southeast. Why? For one thing, the "wind shear", or the change in wind direction and/or speed with height in the atmosphere is higher there. Check out this afternoon's values: esrhPretty impressive along the Mason-Dixon line. What about hail? Here's the SPC hail odds: hailWhat is the most likely type of severe weather in the Youngstown area? Strong, damaging winds. Those odds are about 15% (within 25 miles of any location): windThis jives with this graphic that I put online last night and showed on 21 News at 11: myrisksHow much, if any, severe weather there will be will, again, greatly depend on how much sunshine there is before mid-afternoon. The latest HRRR short range model does not have the CAPE (instability) going through the roof here this afternoon, so it may be picking up on the clouds being tough to break: cape21zNotice the higher values to our southeast and west.Here is an animation of the "simulated" radar, based on the HRRR model, from 3pm-9pm. Notice activity will generally be moving from SW to NE: output_Ct5tIa So, bottom line, we have the CHANCE for severe weather from late afternoon into early evening. Not enough instability will mean thunderstorms will be more "garden variety" and less severe. We will see how the midday and early afternoon plays out.Reminder of our severe weather policy: Severe Thunderstorm Warnings will prompt us to "cut in" in commercial breaks on TV to bring you up to date. In the (unexpected) event of a Tornado Warning ANYWHERE in our viewing area, we will break in over programming. If it turns out to be a long-duration severe weather event, we will have streaming coverage on WFMJ.com, your smartphone and tablet.Also a reminder....Facebook STINKS in severe weather situations, since it "filters" many posts from "like" pages such as mine. Twitter is much better...no filtering!!Thanks for reading!Eric