It is Wednesday morning and the date on the calendar reads July 10th. Remarkably, I am writing about a possible hurricane in the Gulf of Mexico. That fact in itself is not remarkable because we can certainly see tropical activity in this part of the Gulf of Mexico in July. The remarkable thing to me as a meteorologist is that several days ago computer models sniffed out that a low pressure-related "spin" in the atmosphere called a Mesoscale Convective Vortex (MCV) was going to move from the U.S. mainland into the Gulf of Mexico and seed a tropical system. I first wrote about this possibility in Forbes last weekend. If this happens, our current generation of weather models deserve "kudos." As National Hurricane Center meteorologist Eric Blake told me in a previous blog, "it will be true model triumph" if this evolves the way it is trending.
Here are the 4 most important things you need to know about the evolving storm right now.
It has a 90% chance of developing into something tropical. The National Hurricane Center gives the system a 90% chance of developing into a tropical depression or greater within the next couple of days. The 8:00 am Tropical Weather Outlook from the National Hurricane Center says:
A broad low pressure area located over the northeastern Gulf of Mexico about 100 miles south-southwest of Apalachicola, Florida, is producing widespread cloudiness and disorganized showers and thunderstorms. Environmental conditions are conducive for development of this system, and a tropical depression is expected to form late today or Thursday while the low moves slowly westward across the northern Gulf of Mexico. An Air Force Reserve Unit reconnaissance aircraft is scheduled to investigate the disturbance this afternoon.
I will update this article with new information as it becomes available.
The flooding is likely to be really bad. A key point to emphasize is that no matter what category this storm ends up as (or not), it is going to be a significant rainfall producer along the Gulf Coast. The latest precipitation outlook (above) from the NOAA Weather Prediction Center calls for rainfall that could produce dangerous and life-threatening flooding in the Gulf Coast region. The slow march of the storm and rainfall totals potentially reaching nearly a foot or more are a recipe for disastrous flooding. As Dr. Stephanie Pilkington, an expert on hurricane risk and assessment, recently discussed on the Weather Geeks podcast, impacts of tropical systems are far more important to linger on than what category the storm is. Hurricane Harvey and Hurricane Florence should have reminded us of that also.
Some models show the storm developing into a hurricane. Virtually all of the major models have the storm developing into something tropical. A few of our better models have even been hinting at development to hurricane intensity. Ryan Maue is a meteorologist at Bamwx.com. Maue watches weather models carefully, and his Tweet Tuesday evening sums up the scenario well:
Ooof. ECMWF 18z is westward as well. So, two camps: quicker right turn into Louisiana as a weaker system. Or, slower, westward track allowing for powerful hurricane.
The spaghetti plots below give you a sense of the model spread on the system right now. However, the key message is that if you are in the northern Gulf coast, particularly Louisiana and eastern Texas, pay attention.
The storm surge and coastal flooding in a vulnerable region are real possibilities. NBC news meteorologist Kathryn Prociv picked up on something that is of particular concern. She tweeted on Wednesday morning:
This could be very scary. The Mississippi River at Baton Rouge is also in major flood stage, and showing a similar spike on Friday. *Model uncertainty remains.* #LAwx #92L #flooding #surge
She is referring to information issued by the National Weather Service in New Orleans that the river near New Orleans could crest at 19 feet on Friday into Saturday. They noted that the forecast was updated to account for storm surge from the Gulf. Surge in the New Orleans area will be particularly bad if the storm tracks west of the area. The National Weather Service - New Orleans goes on to warn:
The city is protected to a project height of 20 feet. There is still a great deal of uncertainty regarding potential impacts, so please continue to monitor the forecast over the next several days for the latest information. #lawx #Tropics
That's cutting it close folks if the worse case scenario evolves.
