October Snow: The Models Show a Chance This Afternoon Closer To Home

Guns and Roses sang November Rain, but should someone write a song about October Snow? Even the pumpkins were shocked. Last week I mentioned a snowstorm I experience on Halloween at Cornell (Ithaca, NY), but it's still a rarity for them too. Lots of schools were closed and power went out from the heavy snow and high winds.
I have posted the Snow Totals on my story with abc2news.com

Some of the snow amounts over 1 foot extended into the Poconos of northestern PA. Even western Maryland got in on the act.

Here is a snapshot from this morning, showing the snow on the ground at Frostburg State University. Our floor director told me this morning that her daughter went to school there just so she could have more snow. That's a woman after my own heart.






Here is a new, cleaner view of the Upper Level Energy at 500mb (around 18,000ft). This shows the potential for showers to carry over the mountains and reach central Maryland this afternoon and evening.
I've analyzed the wind direction off of the Lakes...and circled the vort max in the orange shading over central Maryland. This is the spin of energy tat should carry the showers over the mountains. The Number [540] is 5400m and represents the thickness of the atmosphere which translates to a layer of near freezing air aloft. Colder air contracts and is less thick in between certain layers.
While downtown temperatures should be around 47F, I expect lower 40s or colder up north near the PA. So the Hereford Zone of Baltimore County and Carroll County should have snowflakes mixed in, thanks to colder cloud temperatures. A burst may occur close to dark, that could coat the grass, but the ground is still relatively warm, so the roads will be fine.
Tomorrow and Halloween we get back to more sun, and a gradual warm up.

Saturday 2nd Post Afternoon:

No Snow= No Shave: Day 9
Will schools be delayed or closed on Monday??? I know it's already the buz, but still uncertain. Below I have detailed why, but just a call for snow in the forecast is not what students and teachers (even my new friends at Cockeysville MS) want. The return of winter is a guarantee, and if there has not been a reason to shave the beard by this time next week, I will be shocked.
My GFS Video Blog is at the bottom of this post showing a few changes I don't trust. As for the first event- Sunday night and Monday: The mid range models (48-60Hr) are now catching on to it. Rather than just show a map plot (you can still see the GFS in this morning's post), I wanted to show some of the extracted text I look at. Below you will see the AVN grid from Texas A&M for BWI. This break down can be overwhelming, so I just wanted to point out the important features. More below image:
First in universal time 00Z (Zulu or Greenwich Mean Time) is at night. and 12Z is morning. So 00Z Monday is actually 7pm Sunday evening, and 12Z is 7am Monday Morning.
While the surface temperature is expected to be 34F-35F, the 850mb temperature (~5000Ft) will be -2F to -4F. That includes the 1000-500mb thickness below 540, and further breakdown not on this output (1000-700mb and 700-500mb) justifies either sleet or a heavy wet snow- that might melt on roads.
It's a very tough call. The total precipitation is .54" liquid equivalent. That's enough if all snow to give 3-5 inches of heavy wet snow. If it was daylight, I would say just wet roads, and white grass. At night is a different story. It's been warm for a while, so the chances of the roads cooling down and beating the trucks will be tough. It was have to be at it's heaviest on Monday morning, which it might be- to get a delay. But further south, the lower your chances (B'more city and AA County). The trend of all models is for more on the E. Shore but warmer temps and into New England up to 1 ft. near Boston. I'll do my best for a snowcast tomorrow.

Video Blog of GFS 240Hr Model:

You win! The Early Snowmap and another model.

The 1st Snow Poll is now closed. I was surprised at the response to not show the early map, yet then final surge just barely won 54 to 50. 20 of you would rather wait until after the storm. Well, here it is, but small enough for those of you who don't want to see it. THIS IS NOT MY FORECAST! I don't know this forecaster, but it came from an Accuweather forecaster on Tuesday. It shows Baltimore in the 3"-6" range. I'm curious to see if he has changed his outlook since then. Again, if you click the image, you may have trouble backing up here. Copy URL and paste back in browser - sorry.
I am off work on Friday I will make my first call here during lunch time. I have posted a new Snow Poll at the right. Here you can share you're best 1st guess of total snow (not including ice, etc) for the Baltimore area. This does not include the northern snow-burbs, but the official report at the airport on Sunday night. I'll run another one on Saturday as well to see if you change your mind.

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More Model Support. Here is a 75 Hr forecast from the SREF my buddy Tony Pann sent me. This is for Sunday afternoon and holds the morning GFS idea. Notices the coastal Low over DE, and MD is on the back side. This looks like the primary, with no occlusion or transfer. This would be in response to a strong block to our north. I'm sure the message boards are lit up this evening with renewed hope.