BLOG: 1st Half of July Recap, Hot Weekend Forecast, El Nino and Our Winter

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This blog post will cover a lot of things, including what the winter may bring. Buckle up! (Click on images to enlarge)July is half over and of course most know that it has been cool and damp so far. Here's how temperatures and precipitation look in calendar form:julytempscal julyprecipcalLook at all those below average days; only 4 days out of 15 have been at or above average. The wet pattern that started at the end of May has continued. This map shows precipitation anomalies (difference from average) over the last 60 days: precipanomSome parts of the region have had over DOUBLE their average precipitation since the middle of May.How has the 1st half of July shaped up versus previous years? 2015 is the last dot on the right hand side. Temperatures: july1sthalfAfter several warm openings to July in a row, the last 2 have been cooler.Precipitation:july1sthalfprecipSo what about the rest of the month? Well after a beautiful day Thursday, we have the hottest weather of the summer coming Friday-Monday. The jet stream right now features a familiar pattern, with a trough, or dip, in the Northeast. That's why it is cool.JETTODAYBut over the weekend, the ridge in the middle of the country will flex it's muscles and the heat will finally get the green light  to come east. Notice how different things look by Sunday:JETSUNDAYSo the heat is coming and it will be accompanied by tropical dewpoints. Heat Index values will be, well, no fun Saturday and Sunday. Find a pool.hisat hisundayOverall, the second half of July is not likely to be too remarkable. The CFS (Climate Forecast System) model shows temperatures perhaps being a bit below average overall:cfstempsPrecipitation, if the model has the right idea, may be near or a bit above average: cfsprecipYou probably have heard about El Nino coming on strong this year. A reminder: El Nino does not "come" or "go" places...you see a lot of silly headlines about "El Nino Coming to California!" in the national press. (Side note: the national press is, in general, AWFUL at covering weather and science. But I digress.)El Nino is a warming of the water in the equatorial Pacific Ocean, near South America.  The one that is evolving may end up being a record strong event. While the effects of El Nino (or the opposite, La Nina) on our weather are typically not as pronounced in the Summer, it can have a big impact on our Winter.We are a LONGGGG way from Winter but just for fun let's look at a couple of things.First of all, in addition to a strong El Nino we have to pay attention to all the warmer than average water off the west coast of North America.sstThis is the positive phase of something called the Pacific Decadal Oscillation and it has had a big influence on our weather over the last 2 winters. All that warm water tends to promote ridging near the West Coast of the US and Canada and when there is a ridge out there often there is a trough over parts of the East. It is a big reason why the last 2 winters have been so cold.To get a hint at what this coming winter might bring, I looked back at moderate to strong El Ninos that occurred in concert with a positive PDO. When you throw all those winters in the hopper and average them, here's what the map looks like in terms of temperatures:analogsCool in the South and warm (compared to average) in the North. A bit warmer than average here.Precipitation:precipanalogsWet along the West Coast and in the Southeast. Dry around the Ohio Valley.These are just a couple of the factors that go into a winter forecast. We will be looking at many more variables as we prepare our official forecast in October. I will say at this early juncture that this winter is not likely to be the 3rd harsh one in a row. Will it be as warm as some El Nino winters are? I am not sure about that; the positive PDO could still play a big role. What about SNOW?? That's a much tougher call and always is. It can still be a snowy winter even if it is not that cold.A look at the years that most closely match our El Nino and PDO conditions shows a variability in snowfall, but a few do come out below average (about 60").: SNOWMuch more on the winter in a few months!Thanks for reading.Eric

BLOG: A Review of June and a Look at July's Forecast

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*Note* Click on the images to enlarge them.June 2015 is in the books and THANK GOODNESS!  June is usually one of my favorite weather months but not this year! It was of course ridiculously rainy and stormy.Let's show you all the ugly numbers. These rain totals are from "backyard" rain gauges; owners upload the data to sites such as Weather Underground. That's how I look at the data.TOTALS1 TOTALS2The official numbers at the airport in Vienna were just as impressive. June 2015 was the 3rd wettest June on record and the 7th wettest month on record in Youngstown.JUNES AllTimeRainNotice the lack of truly dry days. Only 6 days had ZERO rain and many of those were early in the month.JUNECALWhile we had it bad, believe it or not, some places had it WORSE! Especially compared to the average. Many places in northern Indiana and around Baltimore/Washington had their wettest June ever and some had their wettest month overall.juneanomOf course all this rain led to many flooding problems. We had bouts of "severe" weather as well. Severe meaning damaging winds and large hail. Here are the storm reports called into the NWS in June in Ohio and Pennsylvania.ohioreports pareportsTemperatures were not very remarkable in June. We finished the month on a very cool note but overall the month was about a 1/2 degree warmer than an average June. Here are the June temperatures in Youngstown dating back to 1975:JUNETEMPSOk so what about July? I think this July will be similar to last July in that extreme heat is quite unlikely. 90 degree days will be hard to find. We may get a couple. Overall the hottest weather (compared to average) will be in the Northwest. The Plains will be cool. In our area, I think the month will end up being near or perhaps slightly cooler than a typical July.julytempsThe all-important topic of rain is next. We NEED a dry month! But I do not see July being unusually dry. I do think it will be much closer to average than June, but that is not exactly a bold statement. While the wettest weather may be found in the lower Ohio Valley and Mississippi Valley, Youngstown will probably be a bit above average in the rain department.julyrainMonthly rain forecasts in the warm season are tricky because thunderstorms can give some places a lot of rain while others miss. So sometimes the numbers get skewed.Thanks for reading! Enjoy the great weather we have coming for most of the next 5-6 days and have a great holiday.Eric

BLOG: Why Do We Use Dew Point and Not Relative Humidity?

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Meteorologists talk about the "dew point". A LOT. This is especially true in recent years. Many people undoubtedly remember watching weathercasts on TV in which the presenter only talked about "relative humidity". The problem with relative humidity?It's kinda useless.Let me explain why. Imagine if you will 2 cups with water in them. The smaller cup is 100% full of water. The larger cup is only 1/2 full, BUT there is more water in that cup than in the smaller cup.dewpointIf we think of the atmosphere as our "cup", the relative humidity is much higher in the situation on the right but there is actually MORE moisture in the air in the situation on the left. In February it can be 21 degrees with a relative humidity of 100% but that does not mean it is humid. In July, it can be 90 degrees with 32% relative humidity and still feel stifling because of the AMOUNT, or VOLUME of moisture in the atmosphere.So that's why, especially in the Summer, we rarely talk about relative humidity. It can be very deceiving. The dew point is not.In our part of the country, dew point become a big deal when they get well into the 60s and 70s. In mid-Summer, dewpoints in the 50s are a nice treat.dewguide