The Developing Storm and Chance of Snow

As I mentioned on Examiner.com this morning, the models and my resulting forecast changed a bit after the morning package came in yesterday. On that note, I am going to wait until I get the new data to make my post here today. Please check back. In the meantime, the HPC rainfall forecast has gone up from yesterday. I had said that a shift in speed or track may double our totals... well we are getting close to it.

I have kept the regional radar at the bottom of this post, but you can get it on my TV Graphics tab above.

Below is my model analysis, but some of the maps are not easy to read. I have cut out our region, along with highlighting Maryland in a yellow circle.

Late Morning UPDATE:
Now that the models are trickling in, I can see the development, or perhaps over excitement of cold air in the computer models. There is a ton of information to sort through, but what I try to do here is provide the best graphical display. I will try to keep this short, but sweet.
The NGM (here), shows the next development for Saturday morning. This looked heavier on the NAM model, but the rain that moves on late Friday, will be here on Saturday morning, but perhaps break into showers during the day. The arctic boundary to our west will turn rain to snow in Chicago. That white line shows the freezing line. Could be interesting football weather in Michigan mid day.
The NAM shows low pressure slowly passing overhead, and keeping steady rain around through Saturday evening. The low in the Great Lakes looks stronger here, and the band of precipitation behind the freezing line would translate to heavy snow from Chicago to South Bend, IN, and Michigan. The way this wraps up, will pull cold air farther south behind the storm. That will arrive on Sunday- and settle in on Monday.


Snow Next Week?
Here is my personal favorite- the Canadian (from Environmental Canada) showing the surface and upper level maps behind this storm on Monday. On the left, the surface map shows what is left of the Low Pressure Center, just spinning itself out. It is stacked aloft, and circulating cold air around it, while drifting east of the Great Lakes. The black line is the 'freezing' line that is well to our south and moving off of the coast. It does not guarantee freezing temperatures for us, but it supports snow development in the clouds. The image on the right, shows the upper level chart at 500mb. This is the energy needed to generate showers, and there is a lot of it. The push of arctic air moves in during the day, keeping us in the 40s, with an afternoon rain or snow shower. The X in Ohio is the second push with the core of the cold air. That will arrive on Tuesday. This is why I put rain or snow showers for Monday, but snow showers or flurries on Tuesday. Usually the best chance for this is in the hilly terrain north and west of Baltimore, I will fine tune this we get closer. Just showers- but a start and sign of the changing season.

Afternoon Update: Surprise Rain- Is This a Sign?

I had rain in my forecast this morning, but it was just for the northern areas. I did not expect this line to extend as far south as it did. However, the upper level maps this morning, did support it. Here is the 500mb map from the NGM showing the vorticity or energetic 'spin' aloft. This allows not only for enhancement of any showers in the afternoon, but surviving the trip across the mountains. That is exactly what it did, as seen on this radar snapshot from 2pm.

So is this a sign? A sign in this pattern that anything heading our way having a better chance of developing and maxing out. Well, here is the 500mb ma fro Wednesday morning. The next vort max, which essentially is the final push of cold air with this upper level Low, will pass just to our south. The vort max itself is seen in red, and this position is maximum potential for us in central Maryland. Combine this will cold air aloft, and my call from last week may still hold. Perhaps even more so with rain and snow showers not only in the mountains, but we could have the first flakes close to home by lunch on Wednesday. My fingers are crossed. Are yours? If you go to the Seasonal Tab on my full web site, you will see a new page I developed with Ski Bonk. Feel free to scroll around and get in the snow mood.

Here is the long range map from the Japanese Model in honor of Tony Pann. This is the cold air spilling in behind the weekend storm. Although this is a long shot, it does indicate a chance of it ending as snow- at least just west and north as the cloud level temps (850mb) will be near freezing. Still, I think it's a little too early for 'stickage'

Snow Showers- More - Eastern Shore!

Just a shift east, and the beaches may win this round of snow. At the bottom of this post you can see the Snow Advisory Map. The models have pulled back on any accumulated precipitation- but that doesn't mean we are done. This reminds me of what we had back on Jan. 14th- a snow burst. In fact you can see that blog on the right- look for the label (vort max). It could look impressive in spots and coat the ground with less than 1 inch. It all depends on timing and true position of the vort max. Forget the cold front from the west, and the small coastal to our south- here is the NAM 500mb ( roughly 18,000 feet) map. This shows the spin or energy in the atmosphere that can enhance shower. First, a spin at this level will create rising air from the ground and help clouds develop. The timing of late afternoon or early evening acts on any late day heating to enhance it as well. So if you are watching the radar- it might not look impressive most of the day. This feature will enhance the coastal system, but that will be pushed offshore.
Basically- all of us have about the same chance of snow showers- yet the Delmarva may be in the position to have that last longer into the evening, at it will be closer to the of shore Low Pressure. With the chance of 1-2 inches there, this Snow Advisory has been issued for Queen Annes, Talbot, and Caroline Counties. At 12:30pm Kent and Wicomico were added. Watching the current radar- I would suggest a 2-3 inch range for those counties..

Monday Eve. "Why we will get a snow burst Tuesday"

Sorry I forgot to post again earlier. This is just a quick shout out to why I believe we will get a snowburst tomorrow. I know some of you are disappointed we did not get it this morning. These types of storms (Miller B), are Great Lakes systems that develop a new Low off of the Mid Atlantic Coast. It can also hold some warm air and push the storm too far away for us. I had snow at my place, but it was 36F and did not stick- and does not matter to you.
Here you go for Tuesday:
This 500mb WRF plot for midnight and Tuesday afternoon. It shows the vort max (upper level energy or spin) I marked with an X. It is strong, and will be in a perfect spot for us as it passes at the right time for afternoon convection. I would not be surprised is a coating to an inch lays on the north side, but we should get some wind and a burst between 11am and 3pm. The grass, and maybe some roads get a cover, but I will hold the beard until the end of the week.
Thursday is still looking on the fence, or mostly rain- but some eastward push with the models is what I'm watching. I don't want to play it up like I did over the weekend. It will still bring in the arctic air. More on that Tuesday.