BLOG: Quick September Preview

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I will do a blog reviewing the Summer season early next week, but I thought today I would do a quick preview of September. First of all, here is what we know:1) We will continue to lose daylight at a rapid pace in September. The length of our "day" will go from just over 13 hours to under 12 hours. Here's the sunrise and sunset time in Youngstown on the last day of September: sunsetsept302) Our average highs and lows will begin to drop quickly. We start the month with average highs in the upper 70s, but by September 30th, the average high is in the mid 60s: averagesHere is what we THINK we know:1) September will start quite warm and with a fair amount of humidity to boot. The forecasted upper level pattern late next week shows a ridge of high pressure over the Southeast, which will promote steamy conditions across our region: 500thurs 2) The entire first half of September is likely to be warmer than average. This temperature anomaly map shows the average of the last 7 runs of the CFS (Climate Forecast System) model for September 2-12: sept313While there can be a cool day here and there, the models are clearly pointing toward a warm couple of weeks.Here is what we are less confident in:1) The forecast for the entire month. Any monthly outlook is bound to be less accurate than a short term forecast. That said, The long-range models are advertising a warmer-than-average month around Youngstown: septKeep in mind that with the first half of the month likely to be quite warm overall, the second half of September COULD be cooler than average but the warm start could still make the month as a whole above average.Precipitation-wise....it's logical to conclude that if the month is warm in the Southeast, Mid-Atlantic and Great Lakes, and increasingly cooler air masses are trying to invade from Canada....a battle zone will set up somewhere, leading to a wet month in that zone. That's what the latest models are saying: septrainWhile there is a stronger signal for a wet month in the Upper Midwest, we may have more rain than a typical September here as well.Have a good holiday weekend! Hope to see you at the fair.Eric

BLOG: Checking in On Summer So Far...and a Look Ahead

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Happy Friday! Apologies for the downturn in blog posts, social media posts and "Weather For Weather Geeks" videos over the last couple of weeks. You are going to see some exciting changes in our weather operation soon on 21 News and we have been tied up preparing for those changes over the last couple of weeks.We are about halfway through August and this morning's lows were in the upper 40s. Of course, there has been a lot of "buzz" about how cool this Summer has been. We will see what the final numbers are at the end of the month, but since it's Friday and, who doesn't love a Friday Weather Statistics Party??....let's have a look at where we stand.First, the big picture. Here are the Summer (June 1-now) temperature anomalies for the continent: summerusAs you can see, Summer has been coldest (compared to average) across the High Plains. The Northwest has had a warm Summer.Here in Youngstown, it's been a cool Summer, but nowhere near the top of the record books. Coldest Summers (June 1-August 14) on record: 2014avg Seems strange right?? Well keep in mind, June was actually a WARMER than average month. So that skews things a bit. The numbers look different if we look at JULY 1-now: julyaugavgThat seems more in line with the perception of the Summer as a whole.What about August so far? Again, the big picture first: augus  aug1-14Interestingly, LAST AUGUST (orange) was colder (through the 14th) than this year (yellow) in Youngstown.We have certainly had a lot of cool mornings. But again, many years have had more frequent cool mornings. A look at the number of mornings with lows 55 or lower in July and early August:lowsbelow55And, mornings with 50 degrees or below: lowsbelow50So, bottom line...yes it has been a cool Summer, especially since the start of July. But we have had many, many cooler ones. What about the future? Well, of course we are quite cool now....thanks to that big dip in the jet stream over eastern Canada and the NE US: jetnowNext week will feature a pretty decent pattern shift. Here's the expected position of the jet a week from today: jetnextfri Very hot weather can be expected under that ridge in the middle of the country. While the core of the heat is not expected to shift far enough east to give us a heat wave...we can certainly expect some warm weather toward the end of next week into next weekend. There should be at least a couple of days with highs in the mid 80s. Here's the latest CFS model temperature forecast for the 19th through the 24th: cfs19-24We have lower confidence when it comes to what happens toward the end of the month. The latest CFS has another cool period: cfsfairBut I am not sure if that is right yet. Stay tuned! Thanks for reading.Eric 

BLOG: One-Two Punch of Weekend Severe Weather?

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It's a beautiful Summer day today, but trouble may be on the horizon for the weekend. So lets get right to it. While we are enjoying unseasonably cool temperatures, high heat continues to bake the Plains: tempsnowThat dome of heat is going to start migrating east today. While it will not turn HOT here in eastern Ohio and western Pennsylvania, it will turn warmer and more humid tonight into Saturday. Here's Saturday morning's surface map, showing the leading edge of that warmer air: satsfcAs that warm air runs into the cooler air, it will be forced to rise over it, since warm air is less dense than cool air. That rising air will create spotty shower and thunderstorm activity during the day Saturday. Here's the midday simulated radar off of the NAM model: 11amsatNotice how "hit-or-miss" the activity will be.The threat for severe weather will ramp up toward evening. By that time, the atmosphere will have gotten quite unstable across our region (especially to the west of Youngstown), as shown on this map displaying CAPE (Convective Available Potential Energy) values: capesateveA complex of thunderstorms is likely to form somewhere in that zone of very high instability. Last night's NAM model placed it in Illinois and Indiana at 5pm: 5pmsaturdayThen, the model intensified the complex and took it into Ohio later in the evening: 11pmIf this model were to have EXACTLY the right idea (unlikely at this point), that would be a severe wind damage threat for southern Ohio particularly. That "bowing" shown on the simulated radar in SW Ohio is unsettling; that just screams "huge area of wind damage".The Storm Prediction Center outlook for Saturday and Saturday night has all of the region in the Elevated Risk (yellow): day2But, they also see that odds may favor the HIGHEST risk of severe weather being SW of Youngstown. This map shows the percent chance of severe weather within 25 mils of any location: day2catAll that said, let's not dismiss the chance for severe weather across the Mahoning and Shenango Valleys. It's still a period where the risk is elevated, even if the overall HIGHEST risk is to our southwest. The main threat from storms here will be damaging winds. Wind speeds aloft will be getting stronger and any hefty storm could pull some of that wind down to the surface. Winds at 5,000 feet will be up around 40-60 mph and tall thunderstorms can pull down winds from above that level easily: 850windsateveAdditionally, directional wind shear (the changing of wind direction with height) will be pretty significant: srhThis shear will help aid thunderstorm development and also means that an isolated tornado is something we cannot rule out. Here's a look at the threats Saturday evening: risksOk what about Sunday???On Sunday, a strong cold front will be pushing into the Ohio Valley and Great Lakes. sfcsunAhead of the front, the atmosphere will be warm and unstable. The big complex of storms that likely rolled through southern and eastern Ohio overnight will keep pushing to the east and the atmosphere will get a chance to "reload", especially if there is a long interval of sunshine.  Here's a look at Sunday afternoon's expected CAPE values: capesundayTHe Storm Prediction Center has us in the Elevated Risk again: day3So, we expect scattered strong storms to fire along and ahead of that cold front. Much like Saturday, the highest risk will be from damaging winds....but some hail is also possible.Meteorologist Mike Joyce will be in the Weather Center this weekend. Be sure to follow him on Twitter and Facebook. Have a good, safe weekend everyone.Eric