10:45 p.m. update

The latest computer models are still painting a picture of a moderate-to-heavy snowfall across the Philadelphia region.

Like Sunday's storm, the heavier snow amounts will pretty much take place across the same areas.

Unlike Sunday, however, this storm will be much quicker and not produce excessive snow amounts.

That being said, I'm still looking for significant snow to fall as it accumulates rapidly on all surfaces.

The bullseye region should stretch across Philadelphia, Delaware, eastern Chester, eastern Montgomery and lower Bucks counties.

Southern New Jersey, I think, stands the best chance of receiving the brunt of the storm, including Camden, Salem, Burlington, Gloucester and western Atlantic counties. In Delaware, New Castle County is in the heavy snow zone as well.

Snow amounts will be tricky as usual, depending on how intense and exactly where the snow band sets up.

Latest guidance would indicate a general 2-4 inches in the aforementioned locations, with less as you head north of the Blue Route, and along shore locations.

There will be a few isolated pockets in excess of 4 inches but that should be limited due to the rapid movement of the band.

Timing is bad: snow will break out between 7-8 a.m. and rapidly intensify and accumulate across the city and surrounding suburbs.

The snow peak will take place from 9 a.m. to noon, and then rapidly move out between noon and 2 p.m. from west to east.

Temperatures will fall into the 20s, as winds increase.

High impact: morning commute.

Low impact: evening commute - as it will be dry, but frigid temperatures will keep some untreated roadways icy.

Join me at 8 a.m. on Philly.com for live storm updates, analysis and answers to your weather questions.

The next storm is on tap for the first half of your weekend.

John Bolaris

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Get ready for the proverbial one-two punch.

On Sunday we took a strong left hook as record snows stunned the region, now get ready for a stiff right jab as Mother Nature is turning the Delaware Valley into a bit of a snow punching bag.

Here is the set-up:

A dynamic Arctic front is charging this way from the Great Lakes, at the same time a streaking wave will ride the front entering from the Tennessee Valley.

Another intense narrow band of snow should form and again allow for a forcing mechanism (much like Sunday's storm) but this one will be quicker and not the same level of QPF (quantitative precipitation) amount of liquid predicted by the computer models.

The Arctic front and the Southwestern Jet will produce a rapid formation of snow growth starting Tuesday morning as early as your AM rush.

Another band of heavy snow should develop in a flash, hence flash snow storm.

Possible snow amounts in a 5-6 hour period could reach or exceed 4 inches where this band sets up.

The big question of this afternoon is where the band will set up?

Computer models have been waffling, with most indicating the heaviest snow band will set up once again across Philadelphia, southern New Jersey and Delaware.

We lean this way for now, but that could shift either more north or more south. It's more of a wait-and-see as development takes place early Tuesday morning, or what I call in flash situations NOWCASTING.

Timing would have a brief mix changing quickly to all snow during the later half of the morning rush (Please don't hold me to the exact hour!)

This flash snowstorm will be just that - gone in a flash, pulling away by early Tuesday afternoon, with a dry evening commute.

This will be a fluid weather situation, so I'll do my very best to give you the best information possible, but as of now this is a STRONG HEADS-UP!

JOHN BOLARIS