NJ weather: Cool October temps, weekend rain and wind storm

UPDATE... This article is outdated...

For the latest storm forecast information, please refer to my newest weather blog post.

Fall has fallen! And cooler temperatures are here to stay for a while. New Jerseyans will want to grab a jacket Thursday morning, with temperatures mainly in the 40s. Highs will only reach the lower 60s this afternoon, despite lots of sunshine. Same for Friday, sunshine and 60s. And then it's time to start getting serious about a potential coastal storm for this weekend. While Saturday stays quiet and dry, Sunday and Monday will be rainy and windy with significant coastal flooding possible. There's still a wide spread of possibilities in terms of exact rainfall totals, top wind gusts, storm surge estimates, and timing. But I think it's clear this is going to be an inclement — if not downright nasty — Columbus Day Weekend storm for much of New Jersey.

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Thursday NJ weather: Bright sunshine, cool temperatures

Remember just four days ago, when it was as warm as 88 degrees in New Jersey? Yeah, that is but a distant memory now. We are not even going to hit 70 degrees again until the middle of next week, at the earliest. If you have been craving some real October-ish temperature, this forecast is for you.

Thursday is starting with temperatures mainly in the 40s. Urban and coastal areas are near 50 degrees. It's cool, but not cold — owing to a hint of humidity in the air and a slight breeze, just enough to not allow true radiative cooling to take place.

Overall, Thursday will be a nice autumn day. Expect bright, sunny skies and an occasional breeze through the morning. The air will be dry and crisp. High temperatures will only reach the lower 60s — more typical of late October than early October.

One more small issue. A Coastal Flood Advisory has been issued for the Jersey Shore for both Thursday and Friday. The combination of a high astronomical tide and a slight on-shore component to the wind will push tidal waterways about 6 to 12 inches higher, potentially causing minor category flooding in spots at high tide. Not a huge deal, but worth mentioning.

Thursday night will feature clear skies, calm winds, and cold/dry air. Conditions will be perfect for the coldest night of the season so far. In fact, the first frost/freeze of the season seems likely for the coldest corners of the state. Freeze Warnings and Frost Advisories have been issued to the north and west — those are really only relevant for farmers and gardeners.

(Note: The air temperature does not need to cool all the way down to 32 degrees for frost to form. As long as winds are calm enough, the coldest air pools in the bottom inch of the atmosphere, right at grass-level, allowing for ice crystals to form on glass blades.)

The bottom line here is that everyone in New Jersey will probably be reaching for a jacket or sweatshirt late Thursday night through early Friday morning.

Friday NJ weather: First frost, nice autumn afternoon

As I discussed, Friday morning will be quite cool. And even frosty in spots. But the day will turn quite pleasant, once temperatures warm enough to cut through the chill.

Again, we will see plenty of sunshine. Some clouds may start to fill-in late day. But we are staying high and dry to end the workweek. High temperatures will once again end up below-normal in the lower to (maybe) mid 60s.

Saturday NJ weather: The best weekend day

Saturday looks like a fine day. And frankly, the only weekend day without any issues.

Skies will become mostly cloudy to overcast on Saturday, as a storm system slides up the Atlantic seaboard. However, the daytime hours should remain completely dry. High temperatures dump up slightly to the mid 60s. Still a comfortably cool autumn day.

I could see a few spot showers creeping into South Jersey starting late Saturday evening. But the real inclement weather will hold off until Sunday.

Sunday-Monday NJ weather: Rainy and windy

We continue to carefully track a developing coastal storm system (nor'easter) for the Sunday-Monday time frame. All forecast model guidance is now on board with at least some impact to New Jersey — I think the chance is slim for a full "out to sea" escape at this point. Having said that, I am still holding back from a true hyped-up "doom and gloom" forecast here.

With 72 hours to go until the storm really ramps up, there are still plenty of question marks about the exact storm track and intensity. And therefore, the forecast details are still fuzzy.

Here is what we know so far:
💧 It is going to rain, Sunday and Monday. Heaviest will likely be south and coast.
💨 It is going to be windy, Sunday and Monday. Strongest gusts will be along the coast.
🌊 Storm surge is a big concern, with several rounds of significant coastal flooding possible.

Here is what we don't know for sure yet:
💦 How much rain will fall. I have seen rainfall estimates ranging from hardly anything (inland) to upwards of 7 inches (coast) from various model solutions. That is a huge range. And obviously, multi-inch rainfall would have serious flooding potential.
🌬 How strong the winds will blow. 60+ mph gusts are much more impactful and destructive than 20+ mph gusts.
🚨 How much water will be pushed up against the Shore. This may turn out to be the biggest impact of this coastal storm, again a factor of the exact track and wind speeds. If we see several rounds of moderate to major category flooding, with storm surge on the order of 3 or 4 feet, that could be a very serious situation for coastal vulnerable communities.
⏰ When the "brunt" of the storm will occur. Consensus is pointing to the nastiest weather coming either Sunday afternoon or Sunday night. But there is a lot of variety there. I am looking forward to putting together a detailed timeline of how the storm will play out — but we are not there yet.

While I don't think Sunday and Monday will be total washout days, they don't look pretty. Continue to monitor the forecast carefully, especially if you have outdoor plans. I think (I hope) we will be able to add some numbers to this forecast by Friday morning. And then, as always, we will continue to revise and refine that call until the storm is finally out of our hair early Tuesday morning.

5 DAY FORECAST: New Jersey Weather Center