Despite temperatures in the 60s across most of the Garden State Wednesday, a strong winter storm promises to dump snow over NJ throughout Thursday morning.

UPDATE as of 7 p.m. Tuesday...

For the record, I had a pretty significant typo in the "timing" section of my original post. I corrected it below, to reflect that the snow threat will be on Thursday and not Wednesday.

Current watches and warnings from the National Weather Service (blue=Winter Storm Watch)

Additionally, I neglected to include details on the Winter Storm Watch that was issued this afternoon. Here's the breakdown of the watch, county-by-county...

--From 10 p.m. Wednesday to 6 p.m. Thursday for Hunterdon, Mercer, Middlesex, western Monmouth, Morris, Somerset, Sussex, and Warren counties

--From Midnight to 6 p.m. Thursday for Bergen, Essex, Hudson, Passaic, and Union counties

A weather watch is a "heads up" of potentially hazardous weather - it is not a guarantee. In the case of a Winter Storm Watch, it means 6+ inches of snow accumulation may severely impact travel within 48 hours. The watch area will likely get upgraded to a Winter Storm Warning on Wednesday, with additional areas of the state falling under a less-urgent, less-severe Winter Weather Advisory.

ORIGINAL POST from 5 p.m. Tuesday...

I've been calling it a "roller coaster" of a weather week. And it looks like the final drop coming toward New Jersey on Thursday morning will be a doozy, with model consensus now strongly supporting big snow totals for at least part of the state.

Wednesday's highs will happen around lunchtime, with widespread 60+ degree temps expected. (College of DuPage Meteorology)

Temperatures around Wednesday late morning will indeed spike into the lower to mid 60s for most of New Jersey - that's near-record warmth, about 20 degrees above normal for early February. It won't last though, as a strong cold front ushers in colder air starting Wednesday afternoon. As that front passes just south of New Jersey Wednesday night, an approaching storm system will ride along the front through the mid-Atlantic region (south of NJ). As it does, the system is expected to strengthen significantly, bringing heavy snow to the Garden State throughout Thursday morning.

As of this writing, we're less than 36 hours away from first flakes. Forecast confidence remains uncomfortably shaky, given a lack of consistency among forecast models so far and the high sensitivity of temperatures related to precipitation type. However, I believe it's time to start taking this storm seriously, especially if you live and/or work in northern and central New Jersey.

In addition to laying out our latest thinking regarding this winter storm below, I've added a rough measure of my forecast confidence. We may have to make some significant tweaks to this forecast on Wednesday, so it'll be very important to watch what develops.


(Confidence: High)

10 p.m. Wednesday to 2 a.m. Thursday... Showers begin (snow north, mix central, rain south)
2 a.m. to 10 a.m. Thursday... Heaviest bands of precipitation pass through the state, with snowfall rates potentially exceeding an inch per hour. As the rain-snow line drifts southward, more of central and southern NJ will change from rain to wintry mix to snow
10 a.m. to 6 p.m. Thursday... Lingering showers remain possible as the storm system exits

Forecastin' ain't easy... Heavy snow is practically a sure bet for North Jersey, but a tricky transition from rain to wintry mix to snow is forecast for the rest of the state. (College of DuPage Meteorology)

North Jersey: The Snow Zone

Confidence: Moderate

Every afternoon model I reviewed supports the idea of 8+ inches of snow for at least North Jersey. I'm using the Route 1 corridor as a general dividing line. But that should be considered a "fuzzy" demarkation line, given the uncertainty of exactly where the freezing line will start and end its journey during the storm. In any case, this is the area of the state that will see the most challenging travel conditions for the majority of Thursday morning.

Central Jersey: The Unknown Zone

Confidence: Low
The "unknown" moniker I've assigned to this region comes from the transitional nature of Central Jersey's forecast, which leaves a lot of unanswered question marks. As our atmosphere continues to cool at the storm's onset, it will enact an eventual change from wintry mix and rain to all snow. The best chance for heavy snow in this region will be the cooler areas away from the coast (especially along and west of the NJ Turnpike).

If there's one area of the state that is subject to change (either higher or lower), it's this one. Keep in mind, the European model insists almost all of Jersey will see over 8 inches of snow.

South Jersey: Rain-Mix-Snow

Confidence: Low

Oh, South Jersey. What a forecasting pickle you pose. Every model insists snowfall along the south coast (Atlantic, Cape May, and Cumberland counties) will be minimal to none, as above-freezing temperatures keep rain overhead. I'm not convinced, however, and I worry that a quick burst of snow could put some snow on the ground at the tail end of the system. This forecast of 0 to 4 inches represents a wide range of possibilities, but that's necessary at this time given the continued uncertainty over this "rain vs. snow" dilemma.

Overall Impacts

Confidence: High

One mitigating factor in the potential snowfall and accumulation? Those 60 degree temperatures on Wednesday will thoroughly warm the ground (particularly paved surfaces). So the snow may not stick immediately, forcing ultimate snow totals somewhat lower for roadways.

Even so, no matter what falls from the sky, travel conditions are going to be sloppy for several hours Thursday morning. Visibility could be near-zero in the heaviest snow bands, and traction will be poor too. School delays and closings are likely. (Although I caution superintendents, principals, and headmasters to wait until Wednesday evening to make that call if possible, just in case the forecast changes.)

I'm optimistic that the snowy mess will be cleaned up by Friday morning, with quieter but cold weather persisting into the weekend.

As I said above, it's time to start taking this storm seriously and make contingency plans for Thursday. Maybe the groundhog ("weather rodent") was right after all...

Next weather blog update will be published by 7 a.m. Wednesday.

Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook or Twitter for the latest forecast and realtime weather updates.