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2018 Hurricane Season Forecast: What To ExpectLast Edited:
And here I sit on a Friday morning doing one of the least favorite parts of my job – forecasting hurricanes. Now, I don’t dislike forecasting hurricanes, I am a weather weenie after all, but I’m not a fan of forecasting storms that can cause such devastation. We witnessed how many millions of innocent people were adversely affected by last year’s tremendously bad Hurricane season and it was gut-wrenching. Inevitably the one question always comes to mind when watching a storm ravage through another part of the world - “could that happen here?”.
Unfortunately, the answer is yes and it’s not a matter of “if”, but a question of “when?”. I’m not trying to scare you, but it’s about the law of averages. We WILL one day see a major destructive storm come up the coast. I’m not saying it’s this year or next, or even 10 years from now, but one day the conditions will line up just the right way and we will get hit.
Last year saw a record setting season on so many levels. Is that the new norm? No, I don’t believe so. Why you ask? While the season was certainly devastating, we saw it coming. It was similar in form to monster hurricane seasons of the early 1900s, 1930s/40s and the 1960s. We’ve seen numerous powerful hurricanes within the confines of one year many times before. What’s different today then? More people are being impacted and that’s the problem. FAR more people live along the coast than they did 100 years ago. Hurricane Harvey, the storm that devastated portions of SE Texas, can be compared to the Galveston Hurricane of 1900 – similar in setup and impact. Nothing new.
I think it’s important to look back at history and find out how certain types of weather played out in the past and why it happened. It makes forecasting the future a “tad” bit easier when you’ve got a fundamental understanding of “OK this happened under these conditions… put the same things together and we should have a similar outcome”. It works for Winter forecasting, it works for hurricane season forecasting.
With that said, it’s time to talk about what I’m expecting to play out this upcoming season and what has led me to come to this conclusion. As is ALWAYS the case, there are MANY factors that will determine how many storms develop and exactly WHERE they develop. Let’s break down those factors and go over them in detail so you’ve got a solid understanding.
ENSO – El Nino Southern Oscillation
Last year we leaned towards a weak La Nina. All that means is the water in the central to eastern region of the Pacific ocean was cooler than average. With knowing that alone, it was east to conclude that we’d have an active season. Why? When you have cooler water in that part of the world, the trade winds are much weaker going across the Gulf and on over into the tropics. That’s significant because under those circumstances you build a much more stable and favorable environment for the development of thunderstorms which ultimately lead to the production of tropical disturbances, waves, storms and ultimately hurricanes. If there is no wind to tear storms apart, they will form and grow stronger over the warm water.
This year things are a little different. We’ve had La Nina in place all Winter and Spring. I believe it will start to decay as warmer water eventually builds in. By the heart of Hurricane season (which is mid July into September) I’m predicting we see a “Neutral” phase of the ENSO. That means it will not lean in one particular way. Call it “average” if you’d like. Development of tropical systems won’t be as favorable as last year as a result of more trade winds, but I’m still expecting above average activity because it’s not only about the equatorial regions!
LOCATION, LOCATION, LOCATION
I’ll say it again, location. As it stands right now we’ve got PLENTY of warm water off the east coast and close to the continental US. This concerns me because I think we will see more “home grown” storms. That just means storms will likely form closer to the coast. That prognostication is troubling because it gives us less time to track these systems. In a more traditional season we watch the west coast of Africa for waves that build and grow intense on their journey west through the Atlantic. Sometimes we watch a system for a couple weeks! When storms form much closer to the coast, you’ve got less than a week to track and forecast in many cases.
MAIN DEVELOPMENT REGION (MDR)
I think we will see less storms WAY out in the Atlantic and more closer to home (the US) due to where the warm water sets up. Usually the MDR goes right through the Caribbean… this year I’m expecting it to be a bit farther north and it will include the Gulf as well. As the term suggests, it’s the area that sees the greatest likelihood of development. The MDR can change from season to season based on ocean temps and pressure profiles.
HIGH PRESSURE OVER CANADA
I’m going to borrow a term my friend and colleague, Joe Bastardi, coined. “Bridge over Troubled Waters”. What the heck does that mean? Well when you build High pressure over the mainland, storms like to come underneath and head right for the mainland US. The bridge in this case is the ridge in the jet stream that lifts ALL the way into Canada. That combined with a Bermuda High (just to the east of the US) can help steer storms towards the mainland. Long term guidance suggests that this idea has credence.
Living at the coast you need to be prepared at all times for a storm that will come up the coast and bring with it heavy rain, high winds and flooding. It’s a fact of life and one of the risks we take living where we do. Pay close attention to forecasts as tropical storms and hurricanes take shape.
GREATEST IMPACT TO SOUTH JERSEY
Most people focus on the winds of a tropical system, I care more about the flooding potential. Sure we are impacted by winds, but in MOST cases, no worse than a strong nor’easter – which see tend to see 3-5 a year anyway. Tropical systems weaken as they push north so therefore the winds become less intense and less of an issue. Flooding will always be our biggest concern. When talking to OEM folks like Jim Eberwine, it seems to be a common theme. Flooding is dictated by how fast a system moves. The quicker it’s in and out, the worse the flooding is.
However, slow the movement of the storm over a 2-3 day period and SEVERAL tide cycles are impacted meaning the persistent on-shore flow allows “stacking” of the back bays. THAT is DANGEROUS. You end up in a situation where the bays don’t drain out due to the influx of water being pushed ashore. That’s how major flooding is caused. The highest winds are usually short lived – not so much with the flooding.
STORMS: 12 HURRICANES: 6 MAJOR: 2
Slightly above normal season with development of storms closer to the US. Short tracked storms. August and September see the most. With the warmer water closer to the coast, the chances of an east coast landfall becomes more likely. We’re at about 39% chance this year which is up from the 31% in a regular season. How intense storms get will be dictated by specific conditions in the environment in which they development. Steering currents and how fast a storm is moving. The slower, the strong they grow.
A BIG Shoutout goes to my good friend and protege, Allan Nosov of AllanWeatherNYC for his graphics work. Thanks so much!