Latest forecast update: Joaquin expected to become hurricane
Meteorologist Dan Zarrow is tracking the latest developments in the forecast of not one but two heavy rain events heading toward New Jersey.
Update: 11:30 p.m.
In an alert on it's website, the National Weather Service's National Hurricane Center says Joaquin is strengthening and is expected to become a hurricane, possibly by Wednesday morning.
As of 11 p.m. Tuesday, the storm has maximum sustained winds of 70 mph. A hurricane watch has already been issued for the Central Bahamas.
If Joaquin's wind speeds continue to increase to 74 mph or greater, the storm will be upgraded to a Category 1 hurricane. It is important to point out that forecast models have so far done a poor job of picking up on this strengthening trend. That lends little confidence to the current track, intensity, and timing forecast for the storm.
Heavy rain Tuesday night through Wednesday
Before Joaquin even comes into the picture for New Jersey, we will be tracking a batch of heavy rain pushing through New Jersey. It is important not to underestimate or ignore this rain. An inch or two will be a good bet across most of the state through Wednesday evening. The highest rainfall totals are likely to set up in the northwest part of New Jersey, as models have held steady in the 3+ inch range. That's certainly enough for flooding of streets and streams. The lowest totals will probably be along the southern coast.
The most fascinating part about this heavy rain threat? It is clearly being fueled by tropical moisture from Tropical Storm Joaquin and the Gulf of Mexico! The brightly-colored image to the right shows Precipitable Water values early tomorrow morning, which estimates the total amount of water in the atmosphere over a given point. In a perfect world, this number creates a good estimation of rainfall totals. Not only do you notice a maximum in the attached image, but the high values stretch from New Jersey all the way down to Tropical Storm Joaquin. It's a river of atmospheric moisture, that is likely to contribute to some big rainfall totals.
Never underestimate a system that has a connection to tropical air. That includes this heavy rain forecast from Tuesday night through Wednesday afternoon.
Joaquin is strengthening
Meanwhile, Tropical Storm Joaquin has slowly strengthened over the last day, as it slowly drifts to the west near the Bahamas. Here is the latest storm into and forecast track from the National Hurricane Center...
Models remain a mess
Hopefully you got the sense from Tuesday morning's comprehensive "3 scenarios" post that there are a ton of question marks surrounding where Tropical Storm Joaquin is headed. Unfortunately, there has been little improvement in clearing up that forecast through the day.
The latest model run shows one messy plate of spaghetti...
Yes, the latest models show Joaquin may make U.S. landfall anywhere between South Carolina and Rhode Island. Or it may make a sharp U-turn and head back to sea. This morning's solution, showing a strong trend toward a New Jersey landfall, had more confidence than this junk.
All we can do at this point is present the worst-case scenario forecast, prepare to make preparations, and wait for the models to come to a better consensus.
Will Joaquin make landfall in New Jersey?
Frankly, it doesn't matter. No matter where Joaquin goes, this storm is going to have a strong connection to a low pressure system over the Southeast United States later this week. I think odds are increasing that this second heavy rain event of the week will come to fruition.
Biggest Joaquin threat
The heavy rain and associated flash and river flooding concerns me the most at this point, given the abundant atmospheric moisture and the current precipitation forecast. The exact track of Joaquin will heavily influence whether New Jersey sees any tropical storm or hurricane force winds, and/or any coastal impacts such as storm surge. There's still a long way to go in determining if and when Tropical Storm Joaquin will be passing by the Jersey Shore.
I have seen many New Jerseyans compare this storm to Superstorm Sandy, because of the sharp turn in the forecast and since that was the last major tropical system to affect the state. However, if you must make a comparison, consider Tropical Storm Irene from 2011. Irene was a much bigger rainmaker than Sandy, and came from a similar southerly direction. Of course, Irene also had its act together much better than Joaquin - I'm just saying the primary impacts are about the same.
In any case, the overall message remains the same... Tropical Storm (soon to become Hurricane) Joaquin will almost definitely have an weather and/or surf impact on New Jersey. It remains extremely important to monitor the forecast carefully as it continues to evolve.