Weather Will Posted December 16, 2020 Share Posted December 16, 2020 7Z WB HRRR still looks good. One of them is wrong! Or maybe the truth is a blend... Link to comment Share on other sites More sharing options...
Ji Posted December 16, 2020 Share Posted December 16, 2020 [mention=9895]MillvilleWx[/mention] what has better scores at 12-24 hour lead the NAM or HRRR?The hrrr precip wise is more like euro Link to comment Share on other sites More sharing options...
Ruin Posted December 16, 2020 Share Posted December 16, 2020 Honestly this is starting to feel like the storm we had in south central PA years ago where we hit 30 plus I think it was called juno by the weather channel? It was only going to be 6-12 inchs. but early on a few models spit out mid 20s and a model did a 40 incher like the name did to this storm. but then they all kind of lowered totals the next few runs. The mets locally all did a lil jig saying no huge storm I woke up to 12 inchs still snowing like crazy local news still calling for 6-12 it, then the next news cast said 12-18 I had 2 feet by this time and bands sat right above us. then they said final call on the next news cycle was 24 im like i had that 6 hours ago im at 32 or so. I ended up with about 36.8 inchs in my area. I swear this is feeling the same. Link to comment Share on other sites More sharing options...
Ji Posted December 16, 2020 Share Posted December 16, 2020 How can you have 2 high res models give you 8 and 0 inches of snow at the same time 1 1 Link to comment Share on other sites More sharing options...
psuhoffman Posted December 16, 2020 Share Posted December 16, 2020 3 minutes ago, Ji said: 6 minutes ago, psuhoffman said: The frustrating thing is the track is great. Stays offshore. But I think we’re stuck in a no win here. The runs with an offshore track have a worse mid level phase. That’s why they don’t tuck up the bay. But without closing off their mid level circulation even with an offshore track they blast the warm layer inland. The tuck up the bay runs have a much tighter structure due to a closer mid level circulation but the track to the bay screws us. That said the inside track with a better closed circulation/tighter thermal profile seems to be the better result if your NW of 95. It was disheartening to see both the 12k and 3k NAM pull the same identical garbage. The hrrr has similar track to nam but isn't doing this crap That’s why I asked about the HRRR. I’m familiar with the NAM the good and bad. I don’t know much about the HRRR. But one one going to embarrass itself here. This is only a 17 hour forecast and look at the difference from that 0z NAM plot. and the HRRR keeps trending colder every run. Link to comment Share on other sites More sharing options...
MillvilleWx Posted December 16, 2020 Share Posted December 16, 2020 Just now, psuhoffman said: @MillvilleWx what has better scores at 12-24 hour lead the NAM or HRRR? 2 minutes ago, psuhoffman said: The frustrating thing is the track is great. Stays offshore. But I think we’re stuck in a no win here. The runs with an offshore track have a worse mid level phase. That’s why they don’t tuck up the bay. But without closing off their mid level circulation even with an offshore track they blast the warm layer inland. The tuck up the bay runs have a much tighter structure due to a closer mid level circulation but the track to the bay screws us. That said the inside track with a better closed circulation/tighter thermal profile seems to be the better result if your NW of 95. It was disheartening to see both the 12k and 3k NAM pull the same identical garbage. For me, it really depends on the setup. The HRRR does well with 12hr and in and sort of loses some integrity outside that, but I have seen it do well at leads. Typically it does well with mesoscale temp climates inside 8 hrs, especially when it comes to WAA or CAA patterns. This is at least true for west TX. I remember it was unbelievable for one of our snow storms back into the mid 2010's. It was nailing banding structures that other models were struggling with. I was to say it did excellent for 2016 too with banding placement and was solid in the total precip department. It is good with changeover periods too within that 12 hr window. Outside of that, I like the Nam Nest for the mesoscale and short term trends. That's why I'm a little perplexed now given the sharp shift in the 7H and 85H moisture fields which became pretty paltry for most of the sub. The weakened low obviously had impacts on the low level frontogen (850mb) and at 700mb, so that probably had some play. There's a decent PWAT increase on many of the models, so it could be a hiccup, but this would be a bad time for it to sniff something out this close in that would ruin forecasts for many. Hell, it would zap some potential for eastern PA too. Want to see if HRRR continues the course because it's been consistent so far with little deviation in precip structure and increased 850-700mb frontogen placement along and north of I-70. That is fairly textbook too. 3 Link to comment Share on other sites More sharing options...
Ji Posted December 16, 2020 Share Posted December 16, 2020 That’s why I asked about the HRRR. I’m familiar with the NAM the good and bad. I don’t know much about the HRRR. But one one going to embarrass itself here. This is only a 17 hour forecast and look at the difference from that 0z NAM plot. and the HRRR keeps trending colder every run. If the hrrr is this off in its wheelhouse....what's the purpose? The nams have been fluctuating Wildely today. Is the euro still useful now lol? Its been pretty consistent Link to comment Share on other sites More sharing options...
Ruin Posted December 16, 2020 Share Posted December 16, 2020 4 minutes ago, Ji said: How can you have 2 high res models give you 8 and 0 inches of snow at the same time Honestly models suck these days lol esp in the winter months. 1 Link to comment Share on other sites More sharing options...
MillvilleWx Posted December 16, 2020 Share Posted December 16, 2020 4 minutes ago, Ruin said: Honestly models suck these days lol esp in the winter months. They are actually pretty solid overall, but the issue becomes the dynamic nature of these types of events are complex and little deviations from run to run can have influences on everything from SLP strength/placement, height patterns, and that will have a feedback on mesoscale determination. That's why globals are good for upper level pattern recognition and overall schema of of the aforementioned characteristics, but the short term guidance will be finer in the smaller details in shorter time frames, or at least they should be, and a lot depends on initialization and parameterization of the specific model. They also have their biases and that's where trends and utilizing dprog/dt have benefits. Ensembles are meant to smooth means and give a broader scope of a pattern incoming, but they will absolutely miss some of the nitty gritty details that a full deterministic will see. It's all about using everything together and using blends with analysis of current and past obs to delineate what models are having better handle of a pattern progression in both the synoptic and unfolding mesoscale. That's where people at WPC come into play and assist WFO's for forecasts. They see WAY more guidance and data than we do because we don't have time for all that with other duties on a local scale. 5 1 Link to comment Share on other sites More sharing options...
Hurricanegiants Posted December 16, 2020 Share Posted December 16, 2020 GFS 6z? Is that worth a look this close in? Link to comment Share on other sites More sharing options...
psuhoffman Posted December 16, 2020 Share Posted December 16, 2020 7 minutes ago, MillvilleWx said: They are actually pretty solid overall, but the issue becomes the dynamic nature of these types of events are complex and little deviations from run to run can have influences on everything from SLP strength/placement, height patterns, and that will have a feedback on mesoscale determination. That's why globals are good for upper level pattern recognition and overall schema of of the aforementioned characteristics, but the short term guidance will be finer in the smaller details in shorter time frames, or at least they should be, and a lot depends on initialization and parameterization of the specific model. They also have their biases and that's where trends and utilizing dprog/dt have benefits. Ensembles are meant to smooth means and give a broader scope of a pattern incoming, but they will absolutely miss some of the nitty gritty details that a full deterministic will see. It's all about using everything together and using blends with analysis of current and past obs to delineate what models are having better handle of a pattern progression in both the synoptic and unfolding mesoscale. That's where people at WPC come into play and assist WFO's for forecasts. They see WAY more guidance and data than we do because we don't have time for all that with other duties on a local scale. What’s weird is the Euro run at 3k now typically does a very respectable job at picking up meso scale features and warm layers imo. If the NAM is correct it will be one of the worst short range busts I’ve seen it suffer in some time. Some places it has getting 15-20” in southern PA might not hit warning criteria if the NAM is correct. Hell the Euro gave me about 14” (and it was legit not a snow map fantasy) and I might not see more than a couple inches of ice if the NAM is right. Trouble is it’s hard for me to bet against a warm layer. It seems they typically win. Link to comment Share on other sites More sharing options...
MillvilleWx Posted December 16, 2020 Share Posted December 16, 2020 2 minutes ago, psuhoffman said: What’s weird is the Euro run at 3k now typically does a very respectable job at picking up meso scale features and warm layers imo. If the NAM is correct it will be one of the worst short range busts I’ve seen it suffer in some time. Some places it has getting 15-20” in southern PA might not hit warning criteria if the NAM is correct. Hell the Euro gave me about 14” (and it was legit not a snow map fantasy) and I might not see more than a couple inches of ice if the NAM is right. Trouble is it’s hard for me to bet against a warm layer. It seems they typically win. That's the thing that gives me pause. WAA events tend to overperform on the front end, but they also tend to blast further north and west and hold sleet sigs longer for some. I'm still skeptical of the breach of the 81 corridor with it, but it's certainly possible. Meanwhile, HRRR coming in aggressive still with the initial WAA surge lol. What a crazy run of models we've had last 48 hrs. It is 2020. Only fitting. Nothing is easy in the Mid Atlantic 1 Link to comment Share on other sites More sharing options...
Thanatos_I_Am Posted December 16, 2020 Share Posted December 16, 2020 07z HRRR came in noticeably snowier for southern MoCo and HoCo. 08z running now, hopefully a trend? Link to comment Share on other sites More sharing options...
Ruin Posted December 16, 2020 Share Posted December 16, 2020 allowed to post? Link to comment Share on other sites More sharing options...
MillvilleWx Posted December 16, 2020 Share Posted December 16, 2020 The HRRR has been consistent with the northern tier getting absolutely destroyed for several hrs today between 17-21z. Here's an example regional based sounding across the northern areas. This is a great way to get WSW criteria snow before any issues of mixing. Link to comment Share on other sites More sharing options...
Ruin Posted December 16, 2020 Share Posted December 16, 2020 nice just to the south of PA would these bands be going nne ne straight north? Link to comment Share on other sites More sharing options...
MillvilleWx Posted December 16, 2020 Share Posted December 16, 2020 1 minute ago, Ruin said: nice just to the south of PA would these bands be going nne ne straight north? They should absolutely. This is a very good setup for MDT on north. I see 14-22" with local to 25" for you up there Link to comment Share on other sites More sharing options...
MillvilleWx Posted December 16, 2020 Share Posted December 16, 2020 I'm gonna say it now. Someone north of I-70 between 20-00z is gonna see some absolutely insane snowfall. The 85H frontogen is beyond incredible for that area during that timeframe. This reminds me of some of the surprise overperformers in recent past with front end thumps. 1 Link to comment Share on other sites More sharing options...
Ruin Posted December 16, 2020 Share Posted December 16, 2020 4 minutes ago, MillvilleWx said: They should absolutely. This is a very good setup for MDT on north. I see 14-22" with local to 25" for you up there Yea im pretty close to that area 1 Link to comment Share on other sites More sharing options...
Ruin Posted December 16, 2020 Share Posted December 16, 2020 like i said before this is feeling like that juno winter storm a few years ago Link to comment Share on other sites More sharing options...
Interstate Posted December 16, 2020 Share Posted December 16, 2020 26.1/18 Link to comment Share on other sites More sharing options...
clueless Posted December 16, 2020 Share Posted December 16, 2020 26/21 Link to comment Share on other sites More sharing options...
Ellinwood Posted December 16, 2020 Share Posted December 16, 2020 Final... I hate how much sleet is progged to get northwest of I-95, but IMBY in Germantown I would think 3-5" of snow/sleet with downside 2" upside 6-7" is a good forecast. 6 4 Link to comment Share on other sites More sharing options...
yoda Posted December 16, 2020 Share Posted December 16, 2020 Guess we'll find out by 20z whether its the NAM or HRRR that will be right... 09z HRRR says 2-4" in DC by 20z 09z HRRR says its snowing in DC by 10am... by noon its pouring snow in DC proper Link to comment Share on other sites More sharing options...
aldie 22 Posted December 16, 2020 Share Posted December 16, 2020 17 minutes ago, Ellinwood said: Final... I hate how much sleet is progged to get northwest of I-95, but IMBY in Germantown I would think 3-5" of snow/sleet with downside 2" upside 6-7" is a good forecast. Looks solid to me...thanks for sharing! Link to comment Share on other sites More sharing options...
midatlanticweather Posted December 16, 2020 Share Posted December 16, 2020 25/22 Link to comment Share on other sites More sharing options...
Ruin Posted December 16, 2020 Share Posted December 16, 2020 I really hope that moisture field starts filling in more. Link to comment Share on other sites More sharing options...
Weather Will Posted December 16, 2020 Share Posted December 16, 2020 6z WB GFS. 1 Link to comment Share on other sites More sharing options...
NorthArlington101 Posted December 16, 2020 Share Posted December 16, 2020 Scoured the Internet to find RAP data to get a tiebreaker for HRRR/NAM. RAP looks like the HRRR. https://weather.cod.edu/forecast/ 3 Link to comment Share on other sites More sharing options...
Weather Will Posted December 16, 2020 Share Posted December 16, 2020 11 minutes ago, yoda said: Guess we'll find out by 20z whether its the NAM or HRRR that will be right... 09z HRRR says 2-4" in DC by 20z 09z HRRR says its snowing in DC by 10am... by noon its pouring snow in DC proper 2 Link to comment Share on other sites More sharing options...
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