 Welcome to the weather forecast for the week beginning Wednesday, June 10th, 2020. I'm Chief Meteorologist John Ensworth for Longmont Public Media. My normal computer is in for repair, so I'm on a backup today. You just won't see me off to the right of the screen. Saturday, June 13th, we have a last quarter moon rising around midnight and it'll be up through sunrise. So yeah, it won't be one that you'll catch easily, but if you're out in the early morning doing something, you'll see it on a nice show. Some of the biggest news we have right now is our Dericho. I think that's how you say it. I apologize if I'm pronouncing that incorrectly. This is a very rare thunderstorm jet stream related wind event. We had thunderstorms for me in Utah. This line extended up across most of Colorado and went all the way up towards Canada over almost a 24-hour period. We had many wind reports and lots of damage. Some rain even. This is a rare event. Some of the accounts I've seen says this is the first one documented in modern meteorological times occurring over Colorado. There are eyewitness accounts that sound like this phenomena from earlier in history. So certainly they have happened, but they don't happen often. The climatology of these going up to 2003, there's a Utah one there, and eastern Colorado being included in maybe the launching of Dericho. But western Colorado and the mountains, this is our first time. It is Spanish for straight or line as opposed to the twisting motion of winds and tornado. It's specifically defined as a swath of wind damage that extends more than 250 miles, including wind gusts of at least 58 miles an hour. We had winds up at one of the ski resorts, topping 110 miles per hour, along most of the length of the thunderstorms. You may get some well-separated 75 mile per hour wind gusts or greater. This is an old term coined in 1888 by Gustav Heinrich. So when we had the thunderstorms coming out of Utah, let me go back again, the thunderstorm motion itself, the line of thunderstorms, were moving at 110 to 120 miles an hour. And what it's basically happening here is the thunderstorms form kind of make a wall or a dam that interferes with the jet stream flow itself. And some of that energy is imparted into the forward motion of the storms, and some of it is jammed down to ground level where it shoves forward. So you just get this amazing transfer of energy in the upper atmosphere down to the surface. Rainfall was not very significant with this event, even around Boulder. You had a tenth of an inch or less around Longmont. We kind of pulled a tenth to a quarter of an inch of water. We had a cold front come down Monday into Tuesday morning, and that did some more significant water closer to I-25. We had about a half inch to two-thirds of an inch around Longmont in areas south. Boulder only got about a quarter of an inch of water. This front, by Tuesday morning, had pushed out onto the plains. We had significant winds with it, but it was a very different mechanism. It was air from the north coming down, a classic cold front fashion. But this leading edge of Boulder is very sharply defined Tuesday morning. Some of the cool air is spreading down into Texas. This map is departure from normal in air temperature, so it's not an actual measurement of cold versus warm. This little swath of coolness around the Mississippi region is from crystal ball that came ashore over the weekend. It's moisture and circulation is heading up towards the Great Lakes and to die off and head east in southern Canada. The story this week really is this ridge coming back. That is a big ridge in the west. We have the trough out in the east. If we go from Thursday into Saturday, the ridge is pushed out a little bit farther away from us. Let me back up again. I'm doing a lot of backing up today. We have kind of a west to east or slightly northwest flow Thursday, middle of the week. And we have southwest flow, which is going to bring in more warm air into the state for the weekend. This trough is getting closer, but it's not going to really change our weather significantly. The GFS Ensemble has the normal temperature of 81 now and we're rising a little bit over the next 10 day period. Normal low temperature, about 47 for Longmont and we're rising a little bit. The beginning we're in the low end of the normal range and then for the rest of the 10 day period we're riding in the upper part of the normal. Here's Sunday, a little bitty chance of showers and then off next week we have a small chance of showers as well, but it's just not much. The GFS is maybe a little more moist than it should be with the next five days, giving us a little bit of water here. It's more than nothing, but less than a quarter inch, probably about a tenth an inch or less. Over the next 10 days we maybe go to the quarter inch to half inch area, but it's pretty spotty and I don't put a lot of confidence in that. Taking a look at the next seven days, we start out cool as this trough pulls away. We start getting that ridge established Thursday and Friday, so we return to the 90s. The weekend we spend in the upper 80s with maybe a small chance of showers Sunday as that western trough pushes towards us and then rides up over the ridge and then we're back to the 90s next week, very dry throughout this period. For more frequent weather updates check LongmontLeader at LongmontLeader.com. Also get more local news, Longmont in the Front Range. This has been Chief Meteorologist John Ennsworth, your weather forecast for the week beginning Wednesday, June 10th. Keep looking up!