so_whats_happening

This shows some pretty bad forecasts. Late December is the first set of images and the latter is as we close in on mid month.

I am honestly on the fence with it. Typically we only see a full destruction of the SPV 1-2 times a decade. I have a feeling we may have to wait but hope I am wrong.

Never mind they are both standardized. For some reason the CFS forecast looks lower than the other chart. Figured I would also add these two to show the progression better and the overall potential impacts.

Seems as though I was off a bit on overall progression of near normal for the region. Warmth extended a little bit longer than previously expected. As for the AAM maybe it is because it is standardized that it is different from the CFS forecast of showing around -1.

We shall see coming up here overall it may not be needed but it would have been a nice feature to have to get a more sustained pattern to set up.

What an interesting pattern the 00z GFS showed up to 240hrs @ 10mb The 500mb maps were also very interesting, of course one run but don't think I have seen tropo/strato connection in this way with multiple 500mb lobes developing especially one still sitting in the Beaufort Sea/ CAA before. This would probably be considered a minor wave 2 event but not a whole lot of warming taking place which is something that is lacking in completely taking down the SPV.

The issue isnt we should be doing the measuring. The issue is a reliable source for measuring there have already been 2 incidents of bad measurements in the few events we have had. When the the surrounding area is about 2.5-3" and there is clearly 2.5-3" on the ground but only 1" is reported it starts to skew climo data not in a good way. When we get paid to do virtually everything climo wise for the airport but snow is a no go it really doesn't make much sense. We still calculate the snow to liquid it doesn't take away from our duties considering for many many years it was never an issue. The numbers dropped from -1.1 (-1.2 at peak) to now -.8 becoming less coupled everyday.

Yea it is a fascinating climo around here. Yea I was on shift when we got that .2" lol did not expect the season to be just horrid. Unfortunately Baltimore may have some snow total issues for storms in the future. We are no longer measuring as weather observers it is across the airfield now, measured by EMS.

Snowiest winter near me occurred twice since 1990. 1995-96 and 2009-10 topped at around ~72" on the season for both. 95-96 had 30" in one storm, im sure you can figure out the storm, and 09-10 had back to back nearly 2 foot storms in less than a week. Just 3 years ago we set our lowest snowfall ever recorded of .9" We average around 26"

From December until January 2nd subsurface. You can see very little movement has occurred but there is some decent potential showing up that the WWB event showing up may in fact trigger a kelvin wave that has some umpphhh behind it. Im curious if we can finally knock out the pesky cool anomaly that has been around even during the last Nino event around 140W in the subsurface. Im not so certain we push Nino status going into Spring and summer but certainly worth watching if more WWB's start to develop as time goes on. Fun stuff! Beginning of January a bit warmer than I expected but should quickly reverse course in the next week and finally dislodge the cold across Alaska and NW Canada.

Congratulations! Great job forecasting.

DCA _ NYC _ BOS _ ORD _ ATL _ IAH _ DEN _ PHX _ SEA -1.1 -1 -1.7 -0.5 +1.6 +1.9 +1.9 +1.6 +1

Man went for a warmer BOS than anticipated. Also the lack of a break in the warmth out west a bit of a surprise.

I believe a +EAMT should help in maintaining the ridge in the strat and maybe inject a bit of warming aloft. If this is the case I would watch a we go into the first two weeks of January what stirs up. Also hoping we can maintain the -NAO a bit longer to finally put the nail in the coffin.

You can have 2 scenarios that occur. We tend to want the top-down approach for SSWs but bottom up can still be impactful for us. The issue tends to be on top-down it can start to enhance the type of pattern we want (not always of course) with blocking and many times a very wintry time period. The bottom up approach tends to mean the troposphere is experiencing the perfect conditions but things can go awry and do not tend to last as long. Over the years watching while it is nice we do focus on the 10hPa layer I tend to think we should also be focusing on 50-100hPa layers in these displacement events to give us a better understanding of how patterns shake out. This was a wind reversal in the technical sense but was a large wave 1 process that took place with actually limited warming. I think the warming is very important in conjunction with wind reversals as sort of a 1-2 punch. The Atlantic just would not cooperate with us this go around hence the lack of a wave 2 response after the displacement. The Atlantic only just started working for us in allowing, in the last about 2 weeks, this -NAO pattern to set up. If we had the stout ridge from the wave 1 process still around from early in December we would have certainly entertained the idea of a split as we finish out the month. Also don't worry many of us are still trying to better understand the connection the processes have, even myself after many years of looking over the data.