 good day this is the Longmont weather forecast for Tuesday through Friday March 31st to April 3rd happy April everyone I'm Chief Meteorologist John Ensworth let's look at the April 1st Wednesday Moon we're at first quarter oops this waxing crescent well it really is almost because it's not quite at 50% visibility it's about 47% illuminate got to go out later at night to get the exact first quarter but close enough all right there is a big storm coming so let's talk about this thing first off we have this conveyor belt of moisture coming all the tropics across the southern tier of states like our last storm that moving the mountains and kind of tapped into that moisture gave us a good amount of snow and rain so we're gonna get it repeated again in fact this will be the fourth Thursday Friday window in which we've had a cold snap and a storm move in at least a little bit of snow on a Friday so kind of interesting you can get patterns where the jet stream is kind of repeating at a seven-day cycle in any certain location and that's what we have going here up in the Pacific Northwest you can see a low and this is going to be what's digging down and tapping into some of the colder Arctic air to bring down into the States the Arctic air is not going to directly hit us it's going to kind of slide past us to the northeast but it will give us a enough cold air for snow and put us on the boundary with this moisture to give us some good precipitation let's look at it by midnight Tuesday a.m. probably before this video goes up or maybe just about the time this video goes up you can see the big sloppy mess coming into Western Canada and the Northwest U.S. got a big surface low got a cold front ahead of it snow in the mountains rain at the lower elevations down in our neck of the woods our little chance of showers on Monday is moving out on the plains there's a deep southern low riding through the jet stream down there the big picture for the next 10 days we do warm up very remarkably the beginning of the week here and then we see this Thursday Friday and even Saturday morning a window really cooling down and the different model runs the GFS are pretty good agreement that rain or snow is on the way after that your regularly scheduled nice weak weather returns and also it'll be nice for the weekend so that's good but Tuesday p.m. cold front is inching its way down towards us we have that low still sinking down behind the system and we're high and dry by Wednesday morning you can see the storm is getting here finally we got low kind of tense flying over on the Utah Colorado border we got a little cold front pushing through the northern mountains passing the Longmont probably late morning early afternoon ish that will allow temperatures to get pretty warm up ahead of it let me get westerly flow off the mountains will give you downslope so you get warming that way and then as the front pushes in it compresses the air so you get a couple mechanisms for warming that way and the ridge ahead of this trough will still be influencing the area so three reasons you can get some warm weather right before the cold hits with cold air coming in a loft and some moisture available at the surface we will have a chance of a few rummels of thunder from about Denver north and the northern part of our state for Wednesday so with the rain chances increasing afternoon some those might put down a flash of lightning now and then the upper level pattern Wednesday shows what's going on we have that low that was up here Alaska Western Cult Canada coming down into Western Central Canada and a trough stretching off the West Coast a little bit of trough here I didn't mark with a red line but we're on the uphill side of a trough so we get the lift we got the moisture coming in from the tropics the ingredients we need for a storm our Thursday morning the trough is rotating in closer got sort of a double barrel low up here in Canada bringing cold air around the backside of it and we're definitely in the intensifying portion of the storm cold air coming in it changes over to snow for Thursday night the trough is almost here we got cold air in place good amount of lift it's it's really going to give us a nice storm how much well the GFS using a 10 to 1 snowfall ratio because we're still not going to be amazingly cold when you get it's really cold maybe one inch of snow of rain would be 15 inches of snow when its marginal temperatures are closer freezing it's more 1 inch of rain to be 10 inches of snow so we got about 5 to 6 inches of snow possible in this run of the GFS centered right over Longmont extending down to Boulder we we win in the high 25th corridor as far as snow goes the gem model from Canada is not quite so excited it gives the foothills a lot more snow but we get maybe three to four inches of snow right along here right on the plains you get some downslope off the Cheyenne Ridge there I get a little banding down here in the southern west and eastern plains of the state but we're a little notch here of maybe three to four go over to Firestone it might be two to three go a little bit further east and you're down to an inch or so the amount of moisture we were expecting to get through Saturday noon be about a half inch to three quarters of an inch lucky folks might even pull off an inch of water so if you don't have your spring fertilizer out yet this would be a good time to do it because this will water it in nicely and maybe give you some weed control that's what I plan to do so looking at the entire week we start out really warm with showers increasing Wednesday afternoon into the evening one cold front comes in the early afternoon around noon now the cold front comes over in overnight really dropping the temperatures into the 30s for Thursday down to the teens Friday morning we start bouncing back pretty quickly on Friday to the 40s and then back to the 60s and 70s for the weekend but Thursday is going to see a lot of snow not that you're probably going anywhere for more local news take a look at the longmontobserver.org my weather column there is updated quite frequently to keep up with events in the weather and to show you snowfall and rainfall totals after the fact so please visit there this is Ben chief meteorologist John Insworth for the Longmont public media this has been your Longmont weather forecast keep looking up