BLOG: Midweek Severe Weather Threat

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Good morning!I have been mentioning on TV, in my "Weather Geek" videos and on social media that midweek could bring the threat for severe weather to the Valley. This post is an update on the threat....and it's generally good news.First of all, we do have the chance to pick up a shower and thunderstorm during the midday and afternoon today. A cold front is slicing into a warm and humid air mass. Radar/satellite and 9am dewpoints: currentThe odds of large hail in any storm are pretty low today, generally 5% or less (Storm Prediction Center forecast): hailThe threat for damaging winds is in that same general range here today: windNotice how much higher the chances for severe weather are to the west today and tonight. That's because a large complex of thunderstorms, known as a Mesoscale Convective System, is likely to form over the Plains this evening and then track east. Widespread wind damage, large hail and tornadoes will accompany that complex.What does that mean for northeast Ohio and western Pennsylvania? Remember that front I showed entering the region today? It will settle to our south tonight, stalling out near the Ohio River. The farther south that front settles, the lower our chances are for severe weather on Wednesday.  North of the front, a more stable, drier air mass will become entrenched. Check out the dewpoint map for Wednesday afternoon: dewtomorrowDewpoints will have dropped into the 50s here, but they will be in the 70s along the Ohio River. Thunderstorms NEED moisture and will try to track toward areas of higher moisture.This map shows the SPC's odds for severe weather (within 25 miles of any location) Wednesday. Percentages are on the left side: day2Odds certainly are higher closer to the higher dewpoint air. It's easy to see where the higher "fuel" for the storms will be tomorrow by looking at CAPE values: cape18The instability is through the roof along the lower Ohio River Valley but NIL around Youngstown.Alright, so bottom line. I DO think it will rain across the Valley tomorrow, mainly in the afternoon. We will be in the northern fringes of that thunderstorm complex and it will be transporting quite a bit of rain east. This simulated radar, from 12am-2pm, seems reasonable. Notice the complex weakening as it runs into the more stable air: output_McVo61 Those are my thoughts this morning. STAY TUNED! As new information becomes available, these thoughts may change! The atmosphere is fickle.Thanks for reading,Eric 

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

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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.  columstormWith 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): totalsFor 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: dewThat 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: 2pm5pm: 5pmSo, 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: day1windThat 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: gefsJune may shape up to be somewhat wetter than average across the region, if the Climate Forecast System has the right idea: juneThanks for reading and have a good Wednesday!Eric

BLOG: About Sirens and Our Coverage Last Night

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Good morning all! Whew, what a night. It got very busy in a hurry and I want to thank you for tuning into our coverage on TV and on social media. Last night presented many "challenges" for us in the weather communication business and I wanted to talk about that for a minute.The way severe weather warnings are issued and the methods of getting the word out to the public has changed rapidly in recent years. First of all, the National Weather Service now uses a "polygon" warning system. What does that mean?? It means they do NOT, unless necessary, issue severe weather warnings for ENTIRE counties. The warnings are issued only for the part of a county that will be impacted by the storm.This image shows where the Tornado Warning (red box) was out. Just the northeastern part of Trumbull County. 1 This is a GREAT advancement and should cut down on the "false alarm" rate of warnings, by excluding parts of counties that are in no danger.BUT, the polygon system does produce challenges. Many of the ways warnings are communicated to the public have not caught up to the polygon system. For example, the "crawl" that runs at the bottom of the screen on TV? This is automatically generated by default and generally just says the name of the county...not the PART of the county under the warning. We DO have the ability to manually edit the crawl but when we are busy doing live cut ins on TV and keeping social media updated, it can be a challenge.One of the ways I keep my social media sites updated when new warnings come out is by using a service that posts those warnings automatically for me. It's great because I often am on live TV and cannot manually type them on Twitter and Facebook. They look like this: warnNotice, it just says the county name...not the PART of the county. I try, once I am off TV, to supplement these automatically generated posts with a more detailed warning, but again, it is hard sometimes.NOW, LET'S TALK ABOUT SIRENS. Deep breaths. I had a TON of calls and social media comments last night about sirens going off in their communities. Many of these were in western and southern Trumbull County, places that WERE NEVER IN ANY DANGER.On the flip side, on many severe weather days when there is legitimate danger, I get reports of "the sirens didn't go off!!". THIS IS A BIG PROBLEM.Here's the truth about sirens. They are outdated, World War II technology, are inefficient, inconsistently used and in 2014 almost NO ONE should be relying on them for "information". Certainly not as your only source of information. NO ONE should base their decisions regarding seeking shelter based on whether or not a siren can or cannot be heard in their community.Ok, so what should you do? I encourage everyone to have a Weather Radio. They are pretty cheap, readily available, and easy to use. They come in a number of shapes and sizes. radioEveryone should get text alerts on their phones. Go to wfmj.com/weather and sign up for them on the right hand side. alertsEven if you don't use OUR service, use someone's!To sum up, a siren should be the last way you get a weather warning in these modern times. If you hear a siren, quickly assess the situation. Turn on your TV. Listen to your weather radio. Check Facebook and Twitter. See if there is a need for action.If you see on your phone, on TV, on your weather radio and on social media that you are under a Tornado Warning but DON'T hear a siren....TAKE ACTION! Don't wait to hear a siren that may never sound. There have been FAR too many cases in recent years where people were hurt or killed in tornado outbreaks due to lack of action because "there was no siren". Lastly, a word about our coverage on TV last night. I elected not to preempt our 11:00 news with "wall-to-wall" coverage of the Tornado Warning. Many wondered why, and that is a fair question. The truth is, not all Tornado Warnings are created equal. This one was for a small, relatively unpopulated area of Trumbull Co. It was a warning based on weak rotation being picked up by Doppler Radar. I assessed that the threat for an actual tornado was VERY minimal. That, along with the location of the warning, led me to believe that it was unnecessary for us to cover it on TV for 45 straight minutes. I did do 3 special reports during the newscast (in addition to a 4 minute main weather segment) and updated social media with fresh radar images and analysis every few minutes. We also cut into the Tonight Show a few times.I respect those who changed the channel because we did not cover it as if it were an actual tornado emergency. But I did want to give you a bit of an explanation for that decision.Thanks as always for reading and I welcome your feedback!Eric