MillvilleWx

Would absolutely love to chat at some point about all this! I have a lot of feedback to give for even my area of the country and how it fares. Perhaps a virtual meetup with a cocktail is in order? Feel free to PM me!

What you said! Haha NBM is very intuitive and has so many parts, but it is a great tool to use on certain setups, and ice is actually not bad for a general storm sense since it drowns out the noise from the extreme members that could skew means considerably. I will saw it is not the best when it comes to extreme temp variations compared to climo and larger impact events that have a mesoscale foot print like a major snow/ice event or severe out break. They can give an idea of what could occur in a smoothed sense, but knowing your biases can help formulate a better forecast. That is awesome that you have worked with the Blend. I would love to hear more of the nitty gritty with NBM as I've used it for forecast purposes now for almost 4 years.

It's actually a blend of of over 30 pieces of guidance both raw and bias corrected. There's a huge mix of guidance, some of which public doesn't have access to, and some that you do. Off the top of my head, I can name 15 or so, but there's a ton of others. Sorry I can't give the full details on the matter.

NBM at 18z continues to target the northern tier with some ice accretion beginning Thursday night into early Friday before exiting out between 10-12z. A solid advisory type event possible with the current numbers with some sleet also in the mix. Still intriguing to see the totals being spit out by the blend. Even if 75%, it would certainly be a headache for any commute on Friday AM. I would plan ahead if I lived north of I-70, especially away from the Baltimore Metro.

This is the current CIPS Analog guidance with probability of ZR exceeding 3+ hrs within the domain inside a 48hr period. This is centered at 00z Friday, so there's a pretty solid signal for some ZR over areas north of I-70 as shown just using CIPS guidance.

One of the trends I'm noticing in the area of ice accretion is the NBM coming around now to a more pronounced icing scenario compared to its previous runs. NBM is no where near perfect, but it does take into consideration a lot of different guidance and uses a blend of the data to calculate final ensemble means. It also utilizes FRAM Ice accretion numbers, which is more of a true ice measurement process based on a complex algorithm developed by a myriad of meteorologists and data scientists using both a data driven and physical attribution of ice processes that create the overall environment necessary for ice to accumulate. Long story short, it is immensely more accurate a better measure for overall risk assessment and forecasts within operation settings. NBM likely to exhibit a bit of a warm bias given the overall setup and how it underplays the depth of the surface cold layer due to raw data inputs that can skew a mean upward. So, when the NBM is harping at ice accretion within the realm of being more impactful, one has to take notice. Here's the latest NBM forecast signaling the potential at these leads. It will be something to monitor, and I'll update the forum, when I can on these numbers since FRAM is only accessed through internal collaboration and NBM internal products, or a paid site like Pivotal Weather. This is more significant compared to the previous runs with totals approaching the 0.1" over the M/D and even getting into the outer burbs of the Balt/DC corridor. I know I have not been high on this event given my lack of posting (Also been crazy busy out here!), but there's a chance for a modest impact event that would certainly throw a monkey wrench on the Friday AM commute. Definitely one to keep tabs on, especially north of I-70 and the Parrs ridge front into Western HoCo and MoCo.

This is definitely turning to a more northern tier event with Western MD involved, perhaps. I think this is PA/NYS storm by the looks of it. CIPS Analogs is pretty meager for south of the M/D, and there's lots of events that are similar in evolution in the past with good scoring on 5H/7H/85H height fields. Unless we see an abrupt shift with the SLP depiction further south or the blocking up north is stronger, likely going to trend a minor to nada for most of the sub-forum. That's just from everything I've looked at recently.

That's one way to get your adrenaline pumping. Ooof

Happy to see most in the forum get some snowfall. Rounds out the football season nicely with some winter feel. Enjoy the day everyone!

I've been out of the loop the last few days. Been unbelievably busy. Just got a chance to look a bit further. It's certainly a minor event we're looking at here. A majority will see 1-3" but a few spots could reach the 4" mark if things break right. Hi-res guidance has a weak area of 850mb frontogen basically running up the 95 corridor which should be a positive for areas along and NW of the fall line. Temps will be slowly improving through the overnight into the AM, but the modest rates and lack of strong forcing will keep ratios at a solid 8-10:1 with perhaps some slightly higher in the best bands. NBM currently has a wide area of 2" for most with some 3" readings along Parrs Ridge and the higher terrain running along the M/D up to NW of Philly. 18z HRRR was crazy bullish on snow potential surprisingly, so curious to see if it's off its rocker. HRDPS (Yeah I know it sucks) has been somewhat consistent on a 40 mile wide band in CMD that bisects MoCo/HoCo/Balt Co. I'd watch that area and places 20-30 miles either side. Enjoy the snow y'all! Final call: Widespread 1-3" with lolli of 4" over portions of NMD and along Parrs Ridge possibly

Ninas give me an ulcer. Since I've only lived at 40N or south, they have been mostly pain for me. I am less enthused going into the season with them, but I still watch to see if something can surprise.

Right now the timing is still decent with the CAA pre-storm. The PBL improves on approach, which should keep the event either as straight snow, or a touch of rain before changing to snow. The ground temps will cool as snowfall chills the surface with elevated surfaces and grassy areas first to go. It's a standard event, and with it being overnight Sat into Sunday AM, impacts should be pretty low. More of a stats padder by the looks of it. I haven't dug too deep into the event since I've been working and have projects I've been working on for a spring conference, but from what I've seen, its a borderline event with WWA potential for portions of the sub. I don't foresee this changing to something more significant. Missing a prominent southern stream influence to get it to more SECS territory.

This is a drive-by post telling you, "La Ninas in the Mid Atlantic suck." There's several variables necessary for us to get solid storms in the sub-forum in a northern stream dominant setup. Small shifts in amplitude and longitudinal structure of the mean trough can mean whether we get a decent hit or it scurries to the north/south. That said, the GFS was a broader look, but it still managed to get snow into the area with a solid snowfall for Rt 50 on south. A sharper trough should help areas to the north. Time will tell if this trend continues, but the setup is far from dead. I would just temper expectations for places north of I-70 for this one. Further south you are, the better the chances are at the moment.

@WxUSAF The good ole Moco/HoCo deathband

Feb 2013 in Mass was #3 overall on my storms list if you included storms outside the area. It was very close to #2, but the factor of that storm confirming me being a meteorologist supersedes it. Still, it's the best true blizzard I remember outside Feb 9-10, 2010.

1. Feb 5-6th, 2010 (The lead up and the eventual storm was incredible. 32.5" of snow) 2. Feb 12-13th, 2006 (Snowfall rate of 4.5"/hr from 2-3am that morning. Was the storm that full confirmed my commitment to becoming a meteorologist. 20" in 8 hrs.) 3. Jan 2016 (33.5" at work in Germantown; 36" at my apartment in Maugansville near Hagerstown) 4. Feb 9-10th, 2010 (I will never see my neighborhood look that way after that storm and predecessor ever again. 52" base in the backyard. Drifts over 9' high. A Jeb walk to remember that afternoon the 10th) 5. Jan 2000 (I will never forget my dad waking me up because Paul Kocin came on the Weather Channel and mentioned the change to the WSW. Truly one of the most memorable weather experiences of my life) Honorable mentions: Jan 2011 and PDII (Was sick or injured for both so couldn't fully enjoy them); Dec 2009; Dec 2013 overperformer (Ravens/Vikings snow game I attended)

Been out all day. Haven’t looked at anything until the last 15 min since I got home. It was pretty toasty on 70 and down 27 from Mt Airy to Laytonsville area. I will say there was some cooler air out in NE MD where I drove down. Regardless, cold front will move through overnight for the northern half of the sub. Temps will crash pretty quick post front with below freezing by 9am over the northern tier leading some ice accretion. Elevated areas will of course be better for ice formation, but the surface will cool quickly and road conditions will deteriorate the back half of the event. NAM Nest and NSSL WRF are both pretty good agreement with ice potential. FRAM estimates over the northern tier are anywhere from 0.05 to 0.25 depending on model. Mappyland is probably the best spot for ice given the setup. A place like Shrewsbury will certainly be the target for ice. I’d avoid I-83 north of Monkton today if traveling. I still think a light ice is possible for those areas like Damascus/Monkton/Reisterstown with areas along I-70, east of Woodbine a very borderline call. WWA is probably great call right now for the situation. If things break perfect, Hereford zone in Balt Co could get a warning, but that might be a stretch. Either way, cold is coming, so get the jackets ready. I have one more full day here, so I’ll enjoy my precip since it’s hard on come by in West TX. Night y’all!

Interesting upstream trend showing a lot of areas a touch colder than orginiallly forecast for the time being, but the warm nose is more pronounced to the south (Shocker, I know). I still like a climo based event for ice with the northern tier getting the brunt of the ZR risk. Mt PSU will be glazed over like a Krispy Kreme Friday but DC will only be able to see ice if they get a Dunkin Iced Mocha. Areas with sneaky ice potential are spots like Damascus/Clarksburg/Mt Airy/Monkton/Jarretsville.

0.000000000000000002 fathoms

North of Harrisburg, I have no idea what to expect. There is a Central PA forum that has many members from there. They’ve been following this event for days. A great meteorologist is there as well. @MAG5035is awesome and should have a good feel. I’ve been on vacation back here in MD, so I’ve been tracking for my personal needs and for my home area.

12z GFS FRAM Ice Accretion 12z NAM Nest FRAM Ice Accretion

GFS continues to hold firm on the cold push. The NAM Nest was still a pretty solid ice event for areas north of a line of GAI-Savage-Annapolis. A more significant ice event is increasingly likely over areas north of I-70, especially once you get towards Central Frederick/Carroll/Baltimore/Harford counties. Temps will be borderline south of I-70 for areas below 500’. Above 500’ 27-30° will be possible with light/mod precip still in the area. CAA will still be occurring through the AM, so that benefits the icing setup with the FRAM numbers getting more substantial through the AM as a result. I think WSW criteria ice is possible for the northern tier, but a forecast around 0.1-0.2” is probably a good start. Glaze to 0.1 is probably solid starting point south of there. Regardless, local impacts to travel will be likely. Roads will get icy through the day and remain that way thru Saturday AM. It’s not going to be an all timer at first glance, but still not half bad. DC area will likely miss a majority of the ice.

I think for the DC crew, it’s a non event on the latest guidance. I know you live in western HoCo. I wouldn’t be pulling the plug in your hood. Parrs Ridge area down to northern MoCo could still be a mess. I think the areas north of I-70 are in the best shape for ice. Climo winning again

It's definitely got the low level cold now. The interest will be timing and rate of precip. Light precip with falling temps would create some serious skating on the roads potential. Hell, Bob could skate around Rockville with this setup.