psuhoffman

I remember it well...part of the extremely underperforming March/April 2018 period. We had a really amazing pattern and were very unlucky to only get one snowstorm out of it, and yes even with the time of year. We had the miller b rug pull storm on March 8th. There was a good threat around March 14th that got suppressed. We did get the very good storm March 20th but then there was a boundary wave early April that went just to our north and that storm April 7th which did not fail because of being April the wave got suppressed by a NS SW coming across over the top and the worst possible time and pressed the boundary to our south. Yes things can get suppressed in April.

By the way...take a look at the temperatures at Westminster on either side of that 32" snowstorm! This is why I scream at people who say we need to have a cold pattern to get a big snowstorm. This storm was 10"+ in Baltimore and DC also! 1942-03-17, 71, 38, 0.26, 0.0, M 1942-03-18, 69, 46, T, 0.0, M 1942-03-19, 50, 38, T, 0.0, M 1942-03-20, 61, 29, 0.00, 0.0, M 1942-03-21, 60, 40, 0.00, 0.0, M 1942-03-22, 59, 38, 0.54, 0.0, M 1942-03-23, 53, 35, 0.00, 0.0, M 1942-03-24, 54, 30, T, T, M 1942-03-25, 56, 27, 0.00, 0.0, M 1942-03-26, 58, 26, 0.00, 0.0, M 1942-03-27, 57, 30, 0.00, 0.0, M 1942-03-28, 55, 38, 0.00, 0.0, M 1942-03-29, 39, 29, 1.10, 10.0, 10 1942-03-30, 52, 26, 2.20, 22.0, 32 1942-03-31, 50, 36, 0.05, 0.0, 18 1942-04-01, 52, 35, 0.00, 0.0, 12 1942-04-02, 59, 33, 0.00, 0.0, 3 1942-04-03, 67, 45, 0.00, 0.0, M 1942-04-04, 65, 45, 0.13, 0.0, M 1942-04-05, 80, 46, T, 0.0, M 1942-04-06, 84, 50, 0.00, 0.0, M 1942-04-07, 77, 55, 0.00, 0.0, M 1942-04-08, 72, 53, T, 0.0, M

1942: 32" Official reporting station listing below. I was off by a couple days it was the 29-30th. 1942-03-29, 39, 29, 1.10, 10.0, 10 1942-03-30, 52, 26, 2.20, 22.0, 32 Some parts of Carroll county got up to 40"! FYI: the 2016 storm might have beat this, reports across Westminster area were 30-34" in that storm, but Westminster lost its official reporting station in 2012. They had an official reporting station from the 1800s up until 2012 but nothing since. The airport no longer keeps snowfall data. The old barracks did but stopped.

Maybe this is perception bias, but when it came to my ability to predict what a significant storm would end up doing from the guidance, it was easier for me in the late 90s and early 2000s with the old school MRF/AVN/GGEM/ECMWF and short range ETA/NGM. Those models were way way way less accurate, but they tended to be less accurate in a more consistent way. They each had very very very universally consistent bias errors and if you knew how to correct for them they were useful. Now...they are all more accurate in that they are more likely to be closer to the actual truth. But they are much higher resolution and their errors tend to be less consistently in the same direction. This makes it much harder to correct for them and determine what their errors are. Not trying to be controversial here, and I could be wrong...but at times I felt it was easier to forecast using the models 20 years ago in the medium range than now.

Westminster's biggest snowstorm on record was March 31-April 1 Yes the odds of snowfall start to go down significantly past March 10th BUT we've had enough random snowstorms even up until about April 1, especially NW of the fall line, to at least keep an eye on it. See if that random once every 15 years type storm pops up. If you need days and days of snowcover after and let the fact it starts to melt the next day ruin it for you...then ya maybe you should check out. lol

Icon has been better this winter, from my observations. Not great, no model has been great, but its not been any further off than anything else and frankly has been more consistent than some of the other guidance for several events.

Back in the fall several people made the correct point that this winter would be heavily northern stream dominant, and given the state of the northern stream lately (fast and chaotic) it would mean whatever snow threats we did end up getting would be unlikely to resolve at any significant leads. Several people referenced 2013-14 as an example, when we got numerous snow events but they were far from resolved until inside 24 hours! Some, like early Dec 2013, was a positive bust in the nowcast! There was a negative bust for all except the PA line people in early Feb also. Both cases the going forecast as the storm began was WAY off...one turned snowier and one not. But I've found it entertaining and sometimes frustrating to see all the "why are the models sucking arse" posts all winter when this was a known thing coming in, it was predicted over and over...and yet people still expected 100 hour forecasts to end up accurate, knowing that this pattern was not one models would resolve details on at any lead let along 100 hours plus. big picture he is totally right. But...sometimes late in the season this little boundary waves can be sneaky good given the increased baroclinicity. This also seems to be increasing in recent years...maybe elephant related? While it helps us less and less often, when we do get a flush hit from a weak little boundary wave they sometimes are way more than you would think just looking at the synoptics. That isn't something you would forecast from range though, its just something to root for as a "sometimes this can be sneaky good if we get lucky" thing.

cool

I know I shouldn’t stir the pot, but I was bored and it’s soooo easy with him.

@WesternFringe There is 0 chance that 15" report is accurate, for all the reasons you eloquently laid out in a logical rational scientific way. There is also a 0% change that stormy will accept any of those rational logical arguments.

Our temperatures do spike, but that's because the boundary temps are easily warmed in late February and early March by the increased solar input, but this is not necessarily impacting the wet bulb temperature significantly and that is what matters to our snow chances. I think the fact that it feels warmer, and that any snow we do get will melt real quick, gives the false impression that our chances of snow are going down more than they actually are in late Feb and early March.

Our chances of a warning level snowfall event in Baltimore on any given day don't really degrade much until you hit about March 10th when they drop off a cliff quick.

I don't know how to answer this in a simple way so bear with me. The A/B thing is overly simplistic and becomes complicated when you apply the more messy but real parameters of storms. Originally Miller only had his two A/B types but they have since added a ton more to try to resolve the complexity. Originally type A was a gulf wave that rode up the east coast without any transfer. B was a west to east system that jumped to the coast and redeveloped. However, this gets messy because most gulf waves that impact up here start out with a low up west of the apps and then redevelops to the east. Is this A/B? Frankly all storms "jump". Storms don't move. The low pressure continually reforms along the path of best height falls. We say convective feedback error all the time, but convection actually can "pull" a low off its path for a short time due to the meso height falls created. So yes some storms have a more continual path than others but they all jump to some degree, making these classifications overly simplistic. Then you get into phasing. Was it a pure STJ wave moving west to east that simply jumped to the coast or was there some weaker wave that phased with a northern stream SW? How does that impact the definition? What is important to the DC/Baltimore area is not so much "did the storm redevelop or jump" but where the jump happens and how mature the system is and its moisture source. The problem here is the main energy for the storm was a northern stream wave diving southeast that bombed and phased with a very very very weak pacific wave that split off and ejected from the retrograding trough out west. There was not a good moisture feed with the original pacific mid latitude wave and so the system had very little going on until it was captured and phased with the more energetic northern stream system diving in. This is not ideal for our area. Forget the A/B thing, what we need is a healthier wave with better moisture source coming at us from the west that jumps to the coast south of our latitude. Feb 2003. Feb 9 2010. We can do just fine with a transfer system if the wave has a good moisture source and is developing before it gets to our longitude/latitude. We will not if we are waiting on some northern stream wave to bomb out and capture and explode a weak wave just as it gets to us. That almost never works here. There was one in Feb 1996 that worked out...but that's about it. I can't think of any other examples where we had some NS system diving in from the NW waiting to bomb a virtually non existent wave just off our coast and we got into the CCB associated flush hit zone. It always ends up being NJ northeast thing. I called this a miller b because of the transfer and the fact the primary energy was that NS wave. It definitely was not a miller A and honestly I have not kept up with all the various additional definitions they've since added to try to better resolve this debate and I don't care to because it's silly. All storms jump. Ones that have to cross the mountains just have a more pronounced jump because they jump to where the coastal front is located. But some people have the wrong idea that the screw zone is because of this jump. It's because the storm went north of them. The mountains cause the screw zone because of the west wind creates downsloping to the south of the storm track. The appearance of the jump screwzone is more a function of the impact of the mountains. IF the track is south of your location you will usually do fine. But if it is north...yes a west wind once the low gets east of you will cut off the precip, but if the storm had not jumped and kept moving in that trajectory it would have been rain anyways, the mountains and the CAD associated is the only thing that saves places east of there in cases with a west track system...so you can't cherry pick one and ignore the other impact of those mountains. A storm tracking through the midwest going north of Winchester would have screwed them over regardless of a jump. The track is what's more important. Get that low into KY and jump it to off the VA capes and Winchester can do just fine. It tracks into OH/WV and jumps to off MD or north and...yea no good. Sorry I know this was more complicated than you wanted but it's not nearly as simple as the typical A/B debate makes it.

because its a weak POS wave...who cares if we miss 2" of snow! Had the wave been more amplified it would have hit us. If it is that weak I don't even care.

The IVT and the FGEN kind of overlapped for a time. There was definitely an impact because if you look at the obs there is a zone of 6-7" reports in a an area that lines up with about where the IVT was surrounded by generally 2-4" outside that area (except for up here with got to 5-6" purely from the Parrs Ridge effect) then totals went up again once to the eastern part of MD closer to the developing coastal. Some of the guidance over did it, I don't think the 2"/hr rates some guidance had ever developed, maybe because for a time the IVT was actually split into multiple bands instead of one consolidated one.