Longmont Weather Report - September 10, 2026 to September 17, 2026

Welcome to the weather forecast for the week beginning Thursday, September 10th, 2026. This is chief meteorologist John Ensworth for Longmont Public Media. Thursday, September 10th is our new moon. So, right here have sunspots across the face of the sun, but they're not doing anything big or exciting. So, no space weather right now. We've lost 17 minutes of daylight over the last week with sunrise. Now it's 6:38 a.m. on Saturday and 7:13 p.m. For drought conditions, they've gotten worse in the southwestern part of the state. A little better in the northeast plains. And nationally, not much change noticeable. So, I guess that's good news. And with September, drought is expected to get better in the West. Smoke is also not a bad problem with all the dryness and drought. This is just fantastic news that we just don't have big fires going. We're getting close to the end of the precipitation year and this graph will start over. We're at 76%. I think that's up a percent from last week. And all that rain occurred along the Continental Divide and eastward with wandering thunderstorms. looking at the whole spring and summer of severe weather going through August into September. We're just about to be off the map and this will vanish and eventually going to start looking at winter stuff, but um yeah, there's still a little elevated chance and that could happen next week. Thursday, high and dry. Friday, very high and dry. And then thunderstorms come back on Saturday. Nothing severe nearby. We see a front drape to our south that stabilized the atmosphere. >> [snorts] >> Then that washes out. There's a severe weather up in the extreme northern plains. And then a cold front comes down uh into northeast Colorado. A little back door there on Saturday. Uh highs are normal high and low temperatures are dropping pretty quickly. 81 to 77. That is a 4 degree drop. Uh 50 to 47 at night. You can see the actual temperatures are for the most part staying above that except Tuesday. Tuesday is a little cool front and a cool day. record high in this 10day period 96 on the 19th 2010 and ironically lowest ever um for this 10 days. The 20th is also on the 19th and 71. So Tuesday is a cloudier day, cooler day, give you a little taste of fall. The rest of the time not much important. It's also our increased chance of thunderstorms Monday through Wednesday and probably some good precipitation. Nothing notable in the winds. Looking at the um moisture in the atmosphere, our water vapor satellite image has very dry air east of the Rockies. Uh let's put the upper air pattern into motion. So we have easterly or sorry westerly zonal winds at the beginning. We saw that the end of the animation last week. Uh then we've got a little low coming in uh across the northern edge of the nation with a trough finally digging in to the west and that high pressure drops off to the southeast. That's what gives us this big flow from the Gulf of Mexico through Arizona, four corners and over us throughout the middle of the week. And the high doesn't go back into the west until the weekend when we think have things dry out again and the ridge is back going into next week. It's look looks like the ridge center is just there. All right, look at temperatures. We have a cold front coming down into Montana and back doors on Saturday. Pushes away very quickly above normal temperatures. You see the blobs over us start for the afternoon thunderstorms over the weekend and beyond. There's our Tuesday coldront that comes down and it lingers for a day or two and then washes out and the heat comes back. Uh the lower temperatures there all due to moisture coming up into the end of the week and another cold front comes down next weekend stabilizing the atmosphere turning off the precipitation. But again, another taste of fall. Kind of nice. And long-term pattern. Looks like for the winter, they're saying southern half of the nation kind of has that pattern right there. Cooler than normal where the heat is up in Canada and northern states. So, watch this return of moisture. This is precipitatable water and it really is going to develop a flow here on the weekend and beyond of really high levels of moisture. So that's available for our afternoon thunderstorm blowups. So fantastic. You got some blues in there. It's going up the scale so high. Yep. And just there through Thursday and Friday even into Saturday. The moisture is still in place next week. Just the lower atmosphere gets stabilized with that cool front and then it finally starts to thin out a little bit. due points really rich moisture ready to come back 50s just over there on the Kansas border 60 due points and then the weekend it does come back now and then the whole state kind of moistens up and yeah east of the Rockies especially pretty high dupoint levels into Wednesday and Wednesday into Thursday lots of moisture so the atmosphere is moist the low levels are moist moist. Good news for the thunderstorms and all. So, let's take a look at those. These are six-hour frames showing into Thursday and Friday, dry conditions. Saturday, a little bit of stuff in the mountains and then Sunday, the thunderstorm start. The [snorts] western slopes get it that on that first round. Then they go out in the eastern plains. Much of the state has thunderstorm coverage Tuesday. Wednesday's pretty stormy, especially central and southern parts of the state. Most of the state gets thunderstorm coverage on Thursday. And yep, so it there's next weekend rain and at least Saturday. So, and then dries out. So, the next five days, spotty stuff. Eastern uh part of the state, western slopes get much needed water. Then the whole state benefits from returning thunderstorms after that. We start out hot, 90s into the weekend, 80s over the weekend, and next week even cooling down to the 70s with Monday, Tuesday, and Wednesday being sort of a peak. Monday, Tuesday I've got here is stormier than Wednesday. Two weeks out, still above normal temperatures. And September outlook was above normal temperatures. Week two, above normal precipitation, and we're right on the edge of above normal for September. That's it. Have a great weekend and next week. This has been Chief Mid Shaunworth urging you to keep looking up.