Winter Storm Warning Issued For 'Bomb Cyclone' In PA

Click here for the latest updates: 'Bomb Cyclone' Storm Arrives In Pennsylvania

UPDATE, 4 P.M. -- Forecasters have adjusted their predictions, and the "bomb cyclone" winter storm may now have a bigger impact on the Philadelphia region than believed even just hours ago. A Winter Storm Watch has been issued in Bucks, Montgomery, Delaware and Philadelphia counties. It is in effect from 9 p.m. Wednesday to 7 p.m. Thursday.

"Heavy snow and blowing snow expected. Plan on difficult travel conditions, including during the morning commute on Thursday. Tree branches could fall as well. Total snow accumulations of 5 to 7 inches are expected," the National Weather Service said in its Winter Storm Warning. A Winter Weather Advisory is in place in Chester County, where 3 to 5 inches is expected.

Snowfall predictions have increased twice during the day: On Wednesday morning, it was predicted that Philadelphia and its suburbs to the north and east would get just a few inches of snow. Forecasters said the storm would still hit the area with cold temperatures and brutal winds, so we knew we weren't in for a cake walk.

But at noon, an updated map slightly increased snowfall predictions.

A map issued just after 3 p.m. has upped expected accumulations even more.

So much for the bomb cyclone passing us by.

Here is the latest map:

Here was the map as of noon:

Wind chills will be below zero during and after the storm. Expect wind gusts of up to 45 mph, the National Weather Service said in a Hazardous Weather Outlook issued across the region.

Experts predict the storm could evolve into something called a "bomb cyclone," ravaging parts of the Jersey Shore and New England.

RELATED: It's So Cold That The Delaware River Has Frozen Over (PHOTOS)

The "bomb cyclone" is expected to form off the coast of Florida on Wednesday, and winter storm warnings have been issued from Florida all the way to the Jersey Shore. The storm is projected to undergo rapid strengthening, a process called "bombogenesis." It is then expected to evolve into something shaped like — and as powerful as — a hurricane, creating what is known as a "bomb cyclone," according to the National Weather Service.

A "bomb cyclone" can happen when a cold air mass collides with a warm air mass, such as air over warm ocean waters, according to the National Weather Service. "All storms are cyclones, and genesis means the creation or beginning," AccuWeather says. "In this case, bomb refers to explosive development. Altogether the term means explosive storm strengthening."

RELATED: What Is A Bomb Cyclone: Powerful Storm, Polar Vortex Brew

Philadelphia area commuters should take heed: parts of New Jersey and New York City are under winter storm watches and warnings. Three to six inches of snow is expected in New York City. Parts of New Jersey could see up to seven inches of snow.

Experts predict the worst of the storm will hover 20 to 50 miles off the Jersey Shore, although it could hit New England more directly. Besides wind that could knock down trees, signs and poles, there could be incredibly poor visibility on the roadways.

And after the snow exits, the temperatures will dip into the polar vortex range with some of the coldest air of what has, at just two days old, already been a bone-chilling year. Temperatures will be in the single digits and teens through the weekend in the Philadelphia region.

The snow should end by Thursday night, but it won't be melting anytime soon. The high temperature on Friday will be around 13 degrees. It will be even colder on Saturday with a high near 10. The predicted low temperature on Saturday? Minus one.

"I'm just not seeing the enormous snowfalls we'd expect with a blizzard," Ryan Maue, a meteorologist with Weather.us, wrote on Twitter Tuesday night. "Again, it's the wind & extreme cold behind this storm that will be BRUTAL."

Here's a closer look at what to expect from the rest of the week's weather, according to the National Weather Service.

Today: Mostly sunny, with a high near 26. Calm wind becoming south around 5 mph.

Tonight: Snow, mainly after 5am. Low around 18. Calm wind becoming north 5 to 9 mph after midnight. Chance of precipitation is 80%. New snow accumulation of less than one inch possible.

Thursday: Snow, mainly before 2pm. Areas of blowing snow after 8am. High near 24. Blustery, with a northwest wind 14 to 22 mph, with gusts as high as 36 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible.

Thursday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 6. Wind chill values as low as -7. Northwest wind 15 to 18 mph, with gusts as high as 34 mph.

Friday: Mostly sunny, with a high near 13. Northwest wind 14 to 17 mph, with gusts as high as 33 mph.

Friday Night: Partly cloudy, with a low around 2.

Saturday: Sunny and cold, with a high near 10.

Saturday Night: Mostly clear, with a low around -1.

Main image: Source: windy.com