smokeybandit Posted January 28 Share Posted January 28 Euro still has it at 12z Link to comment Share on other sites More sharing options...
Chinook Posted January 28 Share Posted January 28 The Euro and Canadian both have the big storm next week. It's probably way too early to discuss details, but both of these models have temperatures at just freezing. Link to comment Share on other sites More sharing options...
Chinook Posted January 29 Share Posted January 29 Model ensembles/NWS-WPC definitely have a lot of QPF for the West, including the Front Range Link to comment Share on other sites More sharing options...
mayjawintastawm Posted January 30 Author Share Posted January 30 What do folks think in terms of this idea of rain vs. snow? I've not experienced significant rain in Dec-Jan-Feb in my 14 winters here; then again, we haven't had a strong El Nino since we moved. Any kind of upslope before mid-April has always meant snow. The forecasters at Weather5280 are skeptical of rain at this point, favoring mostly snow for most of the Front Range areas. Link to comment Share on other sites More sharing options...
smokeybandit Posted January 30 Share Posted January 30 Hopes seem to be fading for this to be a significant storm for the front range. Link to comment Share on other sites More sharing options...
Chinook Posted January 31 Share Posted January 31 This is the storm that will lend its energy to the Western USA storm. And the models may or may not have read the upper air information from the Pacific really well. We will see what happens. Link to comment Share on other sites More sharing options...
GansettBay Posted January 31 Share Posted January 31 9 hours ago, Chinook said: This is the storm that will lend its energy to the Western USA storm. And the models may or may not have read the upper air information from the Pacific really well. We will see what happens. Would you kindly elaborate on these thoughts for a layman such as myself? I moved to the Front Range from the Northeast a couple of years ago and miss the highly detailed weather discussions in those forums. Nice to see that there's a few of you on here though! Link to comment Share on other sites More sharing options...
mayjawintastawm Posted January 31 Author Share Posted January 31 27 minutes ago, GansettBay said: Would you kindly elaborate on these thoughts for a layman such as myself? I moved to the Front Range from the Northeast a couple of years ago and miss the highly detailed weather discussions in those forums. Nice to see that there's a few of you on here though! Welcome! Basically since there isn't as much measurement in the middle of the Pacific, it's harder to tell the fine details of upstream weather that feeds into the prediction models. But Chinook is a real met and could be more specific. At least around here we don't have to worry as much about rain/snow lines with winter storms... except maybe for this one. Might be a Spring-like elevation storm. My biggest take-home message about winter storms since moving from central MA in 2010 is that QPF can magically go "poof" and vanish at the last minute. Dryness is a bigger enemy than marine warmth. Then, of course, you get things like the storm last May that dumped 6 inches of rain in 30 hours at my house. 1 Link to comment Share on other sites More sharing options...
ValpoVike Posted January 31 Share Posted January 31 5 hours ago, mayjawintastawm said: Welcome! Basically since there isn't as much measurement in the middle of the Pacific, it's harder to tell the fine details of upstream weather that feeds into the prediction models. But Chinook is a real met and could be more specific. At least around here we don't have to worry as much about rain/snow lines with winter storms... except maybe for this one. Might be a Spring-like elevation storm. My biggest take-home message about winter storms since moving from central MA in 2010 is that QPF can magically go "poof" and vanish at the last minute. Dryness is a bigger enemy than marine warmth. Then, of course, you get things like the storm last May that dumped 6 inches of rain in 30 hours at my house. I agree that it definitely has a March spring feel to this storm. Lot's of GOM moisture, but really sharp gradients...and heck why not, this week certainly feels like late March anyways. 1 Link to comment Share on other sites More sharing options...
smokeybandit Posted January 31 Share Posted January 31 Also indicative of a March storm is the models are still all over the place on it. 2 1 Link to comment Share on other sites More sharing options...
GansettBay Posted January 31 Share Posted January 31 7 hours ago, mayjawintastawm said: Welcome! Basically since there isn't as much measurement in the middle of the Pacific, it's harder to tell the fine details of upstream weather that feeds into the prediction models. But Chinook is a real met and could be more specific. At least around here we don't have to worry as much about rain/snow lines with winter storms... except maybe for this one. Might be a Spring-like elevation storm. My biggest take-home message about winter storms since moving from central MA in 2010 is that QPF can magically go "poof" and vanish at the last minute. Dryness is a bigger enemy than marine warmth. Then, of course, you get things like the storm last May that dumped 6 inches of rain in 30 hours at my house. Thanks for the warm welcome! And for breaking that down for me. I moved here from RI so I'm not stranger to rain in February, but I've been waiting for the big one since I've been out here and this seemed promising early on. Overall, it seems like models generally struggle a bit more in our region and it seems to be tough to nail down a confident forecast here outside of 48 hours. I don't do any forecasting myself, but that seems to be the case for a lot of the mets I follow on Twitter and whatnot. 1 Link to comment Share on other sites More sharing options...
ValpoVike Posted January 31 Share Posted January 31 22 minutes ago, GansettBay said: Thanks for the warm welcome! And for breaking that down for me. I moved here from RI so I'm not stranger to rain in February, but I've been waiting for the big one since I've been out here and this seemed promising early on. Overall, it seems like models generally struggle a bit more in our region and it seems to be tough to nail down a confident forecast here outside of 48 hours. I don't do any forecasting myself, but that seems to be the case for a lot of the mets I follow on Twitter and whatnot. Patience is key. We get our big dumps in March and April. I am up near Estes and one of the biggest I have seen was in mid-May. 1 Link to comment Share on other sites More sharing options...
mayjawintastawm Posted February 1 Author Share Posted February 1 A guy named Steven over on Weather5280 looked at all precip events >0.4" water during Feb 1-20 at the Stapleton site over the last 75 years. Exactly zero of 16 were all rain, and the lowest snow/water ratio was 8. So two messages from that: this is indeed unusual, and we still are not at the time of year for big dumps yet, as ValpoVike says. I'm guessing that in RI, there were probably 100 events >0.4" water over that same time period 1948-2023 and probably half were all rain. (I lived in RI 1983-1987 so I get it too). But I'm not going to talk about the Blizzard of '78... Link to comment Share on other sites More sharing options...
Chinook Posted February 1 Share Posted February 1 The models frequently have troubles with forecasting bigger storms at about 5-7 days. The problem is, you tend to think that they have a good forecast for wintertime scenarios if they have some consistency. Then like the last couple of days we saw, the consistency goes away as the models may shift important features such as precipitation. This is partly due to the fact that the models aren't perfect at any time. It's party due to the fact that the models ingest data from geostationary and other satellites. That's pretty much all you get from the Pacific, except for two upper air observations from Hawaii. And as the other guys said, you guys are definitely due some winter to spring snowstorms from El Nino. As you can see, there are no upper air observations from weather balloons off the coast. The models must gain weather information from GOES-WEST and low-orbit satellite types. Link to comment Share on other sites More sharing options...
GansettBay Posted February 1 Share Posted February 1 2 hours ago, Chinook said: The models frequently have troubles with forecasting bigger storms at about 5-7 days. The problem is, you tend to think that they have a good forecast for wintertime scenarios if they have some consistency. Then like the last couple of days we saw, the consistency goes away as the models may shift important features such as precipitation. This is partly due to the fact that the models aren't perfect at any time. It's party due to the fact that the models ingest data from geostationary and other satellites. That's pretty much all you get from the Pacific, except for two upper air observations from Hawaii. And as the other guys said, you guys are definitely due some winter to spring snowstorms from El Nino. As you can see, there are no upper air observations from weather balloons off the coast. The models must gain weather information from GOES-WEST and low-orbit satellite types. That makes a lot of sense regarding the difficulties in predicting storms out here versus ones that have crossed the entire US before hitting the East Coast. I did hear Brian Bledsoe from the Desert Farmer Podcast mention that the el nino pattern is beginning to change. Hopefully we can still get some decent moisture out of it going into the spring. Thanks for the educational content! Link to comment Share on other sites More sharing options...
GansettBay Posted February 1 Share Posted February 1 3 hours ago, mayjawintastawm said: A guy named Steven over on Weather5280 looked at all precip events >0.4" water during Feb 1-20 at the Stapleton site over the last 75 years. Exactly zero of 16 were all rain, and the lowest snow/water ratio was 8. So two messages from that: this is indeed unusual, and we still are not at the time of year for big dumps yet, as ValpoVike says. I'm guessing that in RI, there were probably 100 events >0.4" water over that same time period 1948-2023 and probably half were all rain. (I lived in RI 1983-1987 so I get it too). But I'm not going to talk about the Blizzard of '78... I saw that tweet as well. Those statistics have kept me holding on to hope, but expectations are lowered. I spent most of my life on the coast of RI and snow has become even rarer there. I think they've probably had a dozen rain events over .4" since December. As a snow fanatic it was pretty miserable sometimes Link to comment Share on other sites More sharing options...
GansettBay Posted February 1 Share Posted February 1 4 hours ago, ValpoVike said: Patience is key. We get our big dumps in March and April. I am up near Estes and one of the biggest I have seen was in mid-May. Fingers crossed El Nino continues to bring us enough moisture for some good snows this season. I am in the very northeastern part of Boulder and frequently lose out to those sharp gradients between here and the foothills, but I can't complain after moving from coastal New England. Link to comment Share on other sites More sharing options...
Chinook Posted February 1 Share Posted February 1 1 hour ago, GansettBay said: Fingers crossed El Nino continues to bring us enough moisture for some good snows this season. I am in the very northeastern part of Boulder and frequently lose out to those sharp gradients between here and the foothills, but I can't complain after moving from coastal New England. I wonder how long you've been in Colorado? Like, I mean, normally Boulder gets plenty of enhanced snow rates, the Flatirons to the Front Range is set up nicely for that. The very strange omega-block pattern, with storminess near you guys, will set up as this Pacific jet energy will completely undercut the huge ridge. Undercutting a ridge is something that does happens during El Nino. This is just a weird one. 1 Link to comment Share on other sites More sharing options...
GansettBay Posted February 1 Share Posted February 1 32 minutes ago, Chinook said: I wonder how long you've been in Colorado? Like, I mean, normally Boulder gets plenty of enhanced snow rates, the Flatirons to the Front Range is set up nicely for that. The very strange omega-block pattern, with storminess near you guys, will set up as this Pacific jet energy will completely undercut the huge ridge. Undercutting a ridge is something that does happens during El Nino. This is just a weird one. This will be my second winter in Boulder. I have seen some of the heaviest snow rates in my life since moving here, but I think we only had one storm hit around a 9" total and nothing above 7" since then. I know that temperature is going to be a big issue with this one as well. Is there any shot that the models are overestimating the warmth or is our best hope for this storm to happen at night? Link to comment Share on other sites More sharing options...
mayjawintastawm Posted February 1 Author Share Posted February 1 11 hours ago, GansettBay said: This will be my second winter in Boulder. I have seen some of the heaviest snow rates in my life since moving here, but I think we only had one storm hit around a 9" total and nothing above 7" since then. I know that temperature is going to be a big issue with this one as well. Is there any shot that the models are overestimating the warmth or is our best hope for this storm to happen at night? You might be in a key position to illustrate the variability around Boulder and in Boulder County. As Chinook said, most measuring sites around Boulder tend to report jackpots- BUT they are likely west of US 36. I bet there is often a big gradient SW-NE across town. I wonder if Longmont has a reliable long-term measurement anywhere. To answer your question, I suspect both answers are right. The BOU AFD this morning is a good read. And honestly, big dumps are pretty uncommon. A 12" snowfall happens about every other year in areas below about 7000 feet. It's the 1-2-4" that add up to the average of 50-60 inches. 1 Link to comment Share on other sites More sharing options...
ValpoVike Posted February 1 Share Posted February 1 Spot on with the 7k’ typical cutoff. I am at 7300’ and every spring I do get some respectable dumps, but also have 1 or 2 times where my neighbors 200’ above me get all snow, while I get a mushy mostly rain mix. It is always fascinating the gradients in these spring like storms. Link to comment Share on other sites More sharing options...
GansettBay Posted February 1 Share Posted February 1 2 hours ago, mayjawintastawm said: You might be in a key position to illustrate the variability around Boulder and in Boulder County. As Chinook said, most measuring sites around Boulder tend to report jackpots- BUT they are likely west of US 36. I bet there is often a big gradient SW-NE across town. I wonder if Longmont has a reliable long-term measurement anywhere. To answer your question, I suspect both answers are right. The BOU AFD this morning is a good read. And honestly, big dumps are pretty uncommon. A 12" snowfall happens about every other year in areas below about 7000 feet. It's the 1-2-4" that add up to the average of 50-60 inches. That is some good info, thanks! I did read that Longmont has a yearly average snowfall of 36" versus 96" in Boulder, which as you mentioned, is almost certainly measured west of 36. So I assume my location in East Boulder typically sees far less than that. I checked out the AFD as well. It seems there is a still a bit of uncertainty about p-types between 5-6k ft. It's quite an interesting setup that's for sure! Link to comment Share on other sites More sharing options...
Chinook Posted February 1 Share Posted February 1 2 hours ago, GansettBay said: That is some good info, thanks! I did read that Longmont has a yearly average snowfall of 36" versus 96" in Boulder, which as you mentioned, is almost certainly measured west of 36. So I assume my location in East Boulder typically sees far less than that. I checked out the AFD as well. It seems there is a still a bit of uncertainty about p-types between 5-6k ft. It's quite an interesting setup that's for sure! my thinking is that Ft. Collins/Loveland/Longmont averages over 50" and Boulder was like 76" other notes: up to 61 degrees in Alberta Canada today (also 60's at Lewistown/Great Falls Montana today and yesterday) SPC slight risk near San Antonio (probably not too much discussion needed unless somehow we get a tornado watch tomorrow) Obviously dew points of 50-60 in that area are unusual at this time of year. 1 Link to comment Share on other sites More sharing options...
GansettBay Posted February 2 Share Posted February 2 2 hours ago, Chinook said: my thinking is that Ft. Collins/Loveland/Longmont averages over 50" and Boulder was like 76" other notes: up to 61 degrees in Alberta Canada today (also 60's at Lewistown/Great Falls Montana today and yesterday) SPC slight risk near San Antonio (probably not too much discussion needed unless somehow we get a tornado watch tomorrow) Obviously dew points of 50-60 in that area are unusual at this time of year. Good info thanks! Models didn't seems to overstate the warmth this week and I'm operating under the assumption that this weekend will be no different. It seems like p-types around here will be highly dependent on how strong of an upslope we get. Link to comment Share on other sites More sharing options...
smokeybandit Posted February 2 Share Posted February 2 BOU AFD noted this is one of the most challenging storms seen in the Denver area in quite a while Link to comment Share on other sites More sharing options...
smokeybandit Posted February 2 Share Posted February 2 Link to comment Share on other sites More sharing options...
GansettBay Posted February 2 Share Posted February 2 Interesting that the GFS has shown back to back runs with 12"+ in the metro area. Would this be indicative of optimal upslope and formation of a barrier jet? Link to comment Share on other sites More sharing options...
smokeybandit Posted February 2 Share Posted February 2 GFS, NAM and HRRR are all similar in their most recent runs. We'll see if the Euro comes in line. Link to comment Share on other sites More sharing options...
smokeybandit Posted February 2 Share Posted February 2 And in true GFS fashion in close range, 12z says "what snow?" GEFS still has a solid mean though Link to comment Share on other sites More sharing options...
mayjawintastawm Posted February 2 Author Share Posted February 2 Squinting to the point I'm getting a headache trying to resolve the street-by-street gradient on the 12z model output. It looks like both the GFS and NAM give me 4" of snow, with GFS higher in QPF (1"+ compared to 0.8"). At least the QPF is getting more consistent across what models I can see. I don't think we'll get skunked with precip. Vertical motion and upslope will tell. A barrier jet would be nice, though I think the last time we had one of those it was so tight against the foothills that only places within 10 miles of the hills (Littleton, Golden, Boulder) got a lot. Link to comment Share on other sites More sharing options...
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