For you up-all-nighters, here is a quick look at some of the new overnight data an how it is shifting the forecast for Invest 92L. This continues to be a reasonably low-end-looking storm with the main impacts being rain and flooding. As of now, this isn’t slated to be a Major Hurricane or even a hurricane at all.
As of now, this is forecast to be a Tropical Depression by later this week with the potential to become a Tropical Storm. Beyond that, there are a lot of unknowns.
But here is a look at some of the things that are starting to come into better focus…
From the National Hurricane Center
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Tue Jul 9 2019For the North Atlantic…Caribbean Sea and the Gulf of Mexico:
1. A trough of low pressure located over southwestern Georgia is producing disorganized showers. This disturbance is expected to move southward or southwestward during the next day or so, and a broad area of low pressure is forecast to form over the northeastern Gulf of Mexico on Wednesday. Once the disturbance is over water, environmental conditions are expected to be conducive for development and a tropical depression is likely to form by the end of the week while the system moves westward across the northern Gulf of Mexico. Regardless of whether or not a tropical cyclone develops, this system has the potential to produce heavy rainfall along portions of the northern and eastern U.S. Gulf Coast later this week. For more information about the rainfall threat, please see products issued by your local weather forecast office and the NOAA Weather Prediction Center. Interests along the Gulf Coast from the Upper Texas coast to the western Florida peninsula should monitor the progress of this system.
* Formation chance through 48 hours…medium…40 percent.
* Formation chance through 5 days…high…80 percent.
Main Concern: Rain & Flooding (still)
No matter where this thing goes and what happens, there is a pretty good chance that a lot of places along, and near, the Gulf Coast are going to see a fair amount of rain. And depending on how much it organizes and strengthens, some places could see a lot of rain.
Right now, between the model data, it looks like the Weather Prediction Center has the highest totals across parts of eastern Texas and western Louisiana. There is also a slice of higher rain totals across parts of Mississippi in the official forecast, too. The official forecast fro the WPC calls for between 5″ – 10″ of rain will be possible in eastern Texas and western Louisiana. Between 3″ – 6″ will be possible for parts of Mississippi.
Where this may change
The forecast track is going to dictate who sees how much rain. The official forecast for rain from the WPC is working off of the forecast track for Invest 92L from the NHC. If that track wobbles at all, it could mean big changes to the forecast totals for certain areas.
1) Let’s talk about Invest #92L & where it may ultimately go. As usual, there are different features influencing the motion of the storm.
Beginning with a GFS animation showing the 3 features likely to impact 92L track; The Rockies ridge appears to have the largest impact. pic.twitter.com/0DIGQl0M5J
— Philippe Papin (@pppapin) July 9, 2019
Philippe Papin – as usual – does a great job illustrating how the forecast track could change, and why it is the way it is.
For now, if you live between Pensacola and Houston, you should be assessing your flood risk, making preparations for potential flooding, and making sure your Hurricane Preparedness Kit is ready.
Should certain areas see up to 10″ of rain, that could mean catastrophic flooding. Make sure you know what 10″ of rain would mean for your area. Like always, plan for the worst, hope for the best.
Secondary concern: Coastal flooding & Surge
If Invest 92L does slowly develop and also slowly trek west just off-shore along the northern Gulf Coast, it could mean beach erosion, surge and coastal flooding due to Gulf water inundation along a vast stretch of coastline. Even with a generally modest southerly wind, it could pile water up in places that are not accustomed to seeing water. Low-lying areas near the coast and inland waterways may fill with water and swell more than normal.
This isn’t likely to be catastrophic surge, but mixed with any heavy rain that may fall onshore, it may set the stage for some moderate coastal flooding.
Tertiary concern: Wind after rain
Right now model data isn’t showing signs that Invest 92L is going to be some monster wind storm. Could that change? Sure. Is it likely to change? Not really.
But a prolonged 25mph to 50pmh wind over an area with a rain-soaked ground could lead to trees being downed over a large area – specifically the spots closest to landfall. But also for areas away from landfall.
If you live alonger or near the Gulf Coast between Pensacola and Houston, this may be a good time to go out and prune those trees – just in case.
Some model data
One thing I haven’t touched on yet – in any post – is sea surface temperatures. In a word: warm. Right now, the Gulf water temperatures are running above-average.
The map above shows where the warmest waters exist in the Gulf. The sea-height anomaly is taking into account that warmer water expands, so in the places with the warmest water the physical sea-level will be a bit higher. The readings are taken via satellite and fed through a computer to analyze which areas are the warmest.
The warm water will help this area of low pressure develop and organize by giving it all the ‘food’ it needs. It has also been hypothesized that the warmer waters may help boost thunderstorm development on the southern side of Invest 92L, which would pull the center farther south. Allowing for even more development.
And the farther south it tracks the – potentially – farther west it could make it. But speaking of the movement and track of Invest 92L, let’s talk about the models placement of the system.
The overnight data has pulled back on just how far east Invest 92L may end up. this kind of wobbling with the forecast is normal at this time frame. Before the system forms, computer models have a difficult time nailing track down.
However, good meteorologists can pick up on trends and try to extrapolate what those trends may mean down the line once the system does finally form. In this case, I tend to think that pulling back on the westward track is probably a sign that the models are picking up on either a weaker system, a weaker Bermuda High, or a stronger ridge of high pressure near the Rockies. See the previous post for more information about all of these.
Here is a look at the handful of Spaghetti Models run for Invest 92L at this time:
Notice the difference between how far west these track versus just six hours ago. Or 12 hours ago. This shift was even noted in the European model data through 72 hours. The Euro pulled back to what the model was showing two days ago with the center of Invest 92L south of the Mississippi River in the Gulf.
But try not to get to hung up on the specifics of where this system is at one particular time, since it is likely going to wobble quite a bit in the coming day or two before forming.
What should I do now?
Check your Hurricane Preparedness Kit. That’s about it. Make sure you have enough supplies to last a few days without power and water.
Not because this system is anticipated to wipe out power and water to an area, but rather, you should always have enough supplies to last a few days without power and water during Hurricane season.
