BLOG: Severe Weather Potential Today

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The atmosphere has been busy over the eastern 2/3 of the country this week with lots of severe weather. Thankfully we have not had to deal with much more than April showers to this point. But that may change today.Our Thursday started with some rain as the same front that has been bobbing around all week continues to be a trigger for wet weather. It's easy to find that front this morning by looking at regional temperatures: nowsfcZooming out and taking a look at the country, we have a strong area of low pressure in the Plains and it is moving northeast. As it does so it will drag a warm front in our direction today and temperatures will have little trouble reaching the lower 70s this afternoon. It will even feel humid.nowbigsfcMeanwhile, the juicy air is being transported north by what we call a "low level jet", a fast-moving river of air that is a few thousand feet above our heads. This isn't the "jet stream" that we normally think of, which is up at around 30,000 feet. THat low level jet brings the warm, humid air north and can also aid in creating instability in the atmosphere. Here's the wind at 5,000 feet this afternoon:Notice the brighter colors (faster winds) just west of our region.850The ingredients are coming together for some big storms. But where? The Storm Prediction Center has the highest risk across the Mississippi and lower Ohio Valleys:1This makes sense, given that that region is closer to the low-level jet, there is more "wind shear" (changing of wind direction and/or speed as you go up through the atmosphere) and generally has a more unstable atmosphere overhead. One measure of instability is CAPE, or Convective Available Potential Energy.While we have a moderate amount of CAPE around the Valley later today, it's highest to the west.capeSo, what do we think will happen? There will be a break from the rain during the midday and early afternoon. IF we manage to get some sunshine during that period, it will help make the atmosphere more unstable. A line of showers and thunderstorms looks to push in late this afternoon and evening (roughly 4-7pm). 6pm simulated radar, based off HRRR model:6pmThe odds of severe weather (winds in excess of 58 mph and/or hail 1" or larger), while highest to the west, are not negligible here...generally in the 5-15% range.riskThe primary threat will be damaging winds.11149422_449257775227871_8950276984107845480_nWe will keep you updated all day on TV and social media. If the situation warrants, we will do live streaming coverage later today on wfmj.com.Thanks for reading!Eric

BLOG: Wind, Warmth, Cold, Snow, Storms, Pattern Change!

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Welcome to April! The weather will present plenty of challenges over the coming days so let's get to it. First, a quick review of March, which of course was a chilly month. At least it wasn't as cold as March 2014! marchThe last 2 Marchs really stand out among the last 30: marchgrxAs we head into April the weather will turn active again. Today is a quiet day but tomorrow a strong southwesterly wind flow will usher the warmest air of the season so far into the Valley. Temperatures will make a run at 70 degrees before the day is through! We have to not hit 70 or higher since October 28. Clouds will thicken in the afternoon and while there might be spotty shower activity...the bulk of the rain will occur in the evening and overnight.The atmosphere will become unstable tomorrow in much of the Mississippi and Ohio Valleys. The Storm Prediction Center has a medium risk of severe weather in western Ohio and points SW: day2Notice the WFMJ viewing area is in the Low Risk. There just will not be as much instability here. One thing we like to look at is CAPE (Convective Available Potential Energy) which is an indicator of instability in the atmosphere. (Unstable air means air has no trouble rising and forming clouds and precipitation.)  Mid-afternoon CAPE values are very low locally and higher where that Medium Risk is: pmcapeBy evening, we do get some CAPE into eastern Ohio and western PA but not a lot: capeSo, we are going to allow for the possibility of thunder, but severe weather (damaging winds, large hail) is unlikely locally. Unlikely but NOT impossible. There will be a LOT of wind a few thousand feet up in the atmosphere. Check out the wind speeds at 5,000 feet late tomorrow afternoon: 850windWind will be as high as 70-80 mph at that level and any heavy shower or thunderstorm could pull some of that wind energy down to the surface. So we don't want to rule out a damaging wind gust...but again the overall risk is quite low.There's going to be a decent amount of rain Thursday into Friday as this front stalls just to our south. The SREF (Short Range Ensemble Model) has a pretty big range of rain totals but the mean, or average, of a little over an inch seems reasonable based on all the other information available. srefJust because it will be near 70 Thursday and the calendar says April does not mean we are done with snow yet! I think it is very likely that we will at least SEE snow late Friday night and early Saturday. Cold air will be wrapping in behind a strengthening area of low pressure: SATAMWill the snow accumulate? That's a tougher question but I would say that there is a fair chance that some Valley residents are going to wake up and see at least a coating (if not an inch or so) of wet snow on non-paved surfaces Saturday morning!Easter Sunday is looking "decent". Better than Saturday but still cooler than average. Sunrise temperatures will probably be near freezing and afternoon readings will be in the upper 40s and lower 50s. The GFS model shows a front sparking spotty rain showers: gfs_ptype_slp_ma_19But I am not sure if that is the right idea yet. Some of the other models keep it dry all day. We have a 20% chance of a shower in our forecast on TV and I think that is fine for now.What about the longer range? When will TRUE Spring arrive? If you have been following my posts and videos, you know I have been advertising a pattern change toward the middle of April that will allow for many more above average days than we have had in the last few months. I still think that is the right idea. It's mostly good news for the whole country; the East finally gets a chance to warm up and the parched West will finally get some precipitation. The pattern in 2 weeks or so should look something like this: 500day15Notice the big trough in the West and the ridge in the Midwest/Northeast. This pattern will result in some warm days for us (80 degrees at some point?). I said above "mostly" good news. The bad news? This pattern will likely result in a lot of severe weather across the Plains states. We don't want to see that.The 8-16 day outlook has warm colors on it. It's been a longggg time since it looked like this: 816The long range climate models are portraying April as a warmer than average month overall in Ohio and western PA. We deserve it! aprilThanks for reading,Eric