WxWatcher007

Central Tropical Atlantic: Shower and thunderstorm activity associated with a tropical wave located about midway between the Lesser Antilles and the Cabo Verde Islands show some signs of organization. Environmental conditions are forecast to become more favorable for development by tomorrow, and a tropical depression is likely to form on Wednesday or Thursday while the system moves west-northwestward to northwestward across the central Atlantic. * Formation chance through 48 hours...low...30 percent. * Formation chance through 7 days...high...80 percent.

Hurricane Gabrielle Discussion Number 24 NWS National Hurricane Center Miami FL AL072025 500 PM AST Mon Sep 22 2025 Gabrielle has continued to become better organized this afternoon, with very cold cloud tops in the eyewall and a warm eye. Data from both NOAA P-3 Hurricane Hunter aircraft confirm satellite estimates that Gabrielle is a category 4 hurricane, with peak 700-mb winds of 129 kt in the eastern quadrant a few hours ago. Additionally, tail-Doppler radar data showed maximum 0.5 km winds of 135-140 kt on the last pass, and the double eyewall structure has consolidated into a single eyewall again. These data supported an intensity of at least 115 kt at 18Z, and with the slight improvement on satellite since that time, the initial wind speed is set to 120 kt. The hurricane is moving to the north-northeast at about 10 kt. There are no important changes to report to the track forecast, with the subtropical ridge providing a seemingly reliable steering for the next several days. Gabrielle is forecast to turn northeastward overnight and then move at a more rapid pace to the east-northeast during the next few days due to stronger mid-latitude flow. The new forecast remains on the faster side of the guidance, closer to the Google DeepMind and GFS model. Extratropical transition is expected late on Friday while the system is in the vicinity of the Azores. Little significant intensity change with Gabrielle is expected as the cyclone begins to move into a less conducive environment, though the overnight diurnal convective max should help the hurricane maintain its strength in the short term. A combination of cooler waters and increasing shear should cause Gabrielle to start to weaken by late tomorrow. While SSTs drop off notably by midweek, an upper-level trough is likely to provide extra divergence aloft, keeping the hurricane stronger than other environmental conditions might suggest. The new NHC intensity forecast is quite similar to the previous one, showing a gradual weakening during the long-range forecast and near the model consensus. KEY MESSAGES: 1. Swells generated by Gabrielle will continue to affect Bermuda and the east coast of the United States from North Carolina northward, as well as Atlantic Canada, during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. 2. Gabrielle is forecast to approach the Azores late on Thursday. Interests in the Azores should monitor the progress of Gabrielle though it is too soon to specify the magnitude of potential wind, rainfall, and wave impacts. FORECAST POSITIONS AND MAX WINDS INIT 22/2100Z 31.7N 61.8W 120 KT 140 MPH 12H 23/0600Z 32.8N 60.4W 120 KT 140 MPH 24H 23/1800Z 34.2N 57.5W 110 KT 125 MPH 36H 24/0600Z 35.2N 53.0W 100 KT 115 MPH 48H 24/1800Z 35.7N 47.3W 90 KT 105 MPH 60H 25/0600Z 36.3N 40.7W 80 KT 90 MPH 72H 25/1800Z 37.7N 34.0W 70 KT 80 MPH 96H 26/1800Z 42.8N 22.9W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 27/1800Z 44.5N 15.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Blake

Euro would get some remnant rain into the region

Good candidate for our next major…

Might be a weak TS verbatim but as you know it’s more important to see the steering patterns that trough is really what make this a land threat as a ridge builds over the top and it’s not crazy far out—only about a week away. Short fuse system.

It’s going to remain all over the place for a bit. A lot of uncertainty with this one with the upper level pattern the opposite of this at 00z on the Euro. But for up here we want to see that trough migrate from the SE to the GL region in future runs with far less troughing to our north lol.

This one could very well end up further west than Gabrielle. Would definitely watch in Bermuda. I expect the odds to go up at 2pm. It still has disorganized convection but it looks like it’s trying to consolidate.

Yeah as long as you have that flow over New England this one won’t get here. Could still do something further south though.

Unlike Erin, it looks like the lead wave could get west enough where even if there’s a trough around there could be a land threat. Steering pattern still looks a bit weird though.

I’m modestly intrigued. I said in my forecast that if there were an EC threat this year it’d be a shorter fuse wave that develops in the western Atlantic. That lead wave fits the bill. But it’s all just speculation at this point.

Peak Season Forecast (Aug 20-Oct 20) Named Storms: 10 (2) Hurricanes: 6 (1) Major Hurricanes: 3 (1) Fernand, Gabrielle (MH) Thank you Gabby! More likely on the way.

Really took off. GREAT for my forecast lol.

The tropics are active now with three systems being monitored. This is the thread for the current orange nearing the Leeward Islands. The forecast for this wave is complicated, with more implications for land than our central Atlantic cherry. The signal for development is not as strong as the Atlantic cherry, but this morning there is a modest amount of convection. The key to this wave and its possible risk to land is that it is likely to stay weak as it pushes across the northern Leeward Islands, bringing rain and gusty winds, but it finds a potentially more favorable environment for development in the southwest Atlantic. While the GFS has led the way in signaling development, in its latest run it consolidates both waves in five days off near the Bahamas. Meanwhile, the Euro, which was more bearish originally, keeps both waves separate. It is critical to see how the upper level pattern over the east coast develops, and whether the strength and orientation is enough to kick both waves out to sea or create an east coast threat. This one is definitely worth watching.

Yeah it’s time to break out the discussion with the trends continuing. Threads on both coming now.

The tropics are active now with three systems being monitored. This is the thread for the current central Atlantic cherry. There has been a strong cross guidance signal for days that a central Atlantic wave will develop. The models have actually been quite robust with this wave once it develops, in similar fashion to the rapidly intensifying Gabrielle. The AI ensembles, which have done a particularly good job sniffing the environment out, are particularly strong. Now, while the majority of guidance turns this out to sea without threatening any land masses, the amplitude and timing of a trough in the coming week will determine the eventual evolution, along with where this develops. I expect this to develop first if both waves develop.

It may be starting to take off with deep convection now wrapping fully around the center. It has a narrow window before environmental conditions become more hostile but the once anemic Gabby may put on a show before the curtain falls.

It’s a spectacular system

Model noise most likely. Most ensembles have nothing there with the focus on the SW Atlantic over the next week to ten days.

Gabby is now a hurricane after undergoing RI, and is forecast to become a major. Huge for my forecast. The models are also bullish on the central Atlantic wave developing, and possibly the leading wave. We’ll see if that trend continues but it’s a good look so far for my forecast…

There’s no need for a thread quite yet imo. It does look like conditions are becoming more favorable in the western Atlantic. It’ll be interesting to see if the trend toward the leading wave and central Atlantic area continues to move toward development.

Now forecast to briefly become a major. While the structure of Gabrielle on geostationary satellite is still a little ragged with warmer cloud tops than this morning, it has become more axis-symmetric, and a recent AMSR2 microwave pass at 1733 UTC indicates a thicker 37-GHz cyan ring than the one observed this morning. 18 UTC DTOPS guidance, which did well predicting Erin's rapid intensification period earlier this year, is now indicating a 62 to 76 percent chance of a 30 kt increase in intensity over the next 24 h. Thus, I see no reason to not forecast continued steady to rapid intensification over the next 24-36 h, which is in line with the higher end of the intensity guidance, but not as high as the most recent HAFS-A run. After 36 h, SHIPS guidance shows southwesterly shear steadily increasing, and this should lead to steady weakening through the end of the forecast period. There is still some question as to Gabrielle's structure at the end of the forecast and whether it will be losing tropical characteristics. The southward shift in the forecast track suggests it might hang on to tropical characteristics a little longer than originally expected. The intensity forecast falls back close to the IVCN and HCCA consensus aids by the end of the forecast period.

Definitely a grain of salt but anything in that region would be worth watching with uncertainty about the depth and orientation of next week’s trough. This is pretty similar to what I thought in my peak season outlook with activity concentrated in the SW Atlantic. The late month CAG signal seems muted for now.

NHC has now designated that lead wave as a lemon. The GFS and AI ensembles have been more bullish on development odds while the Euro has basically nothing until the 12z run.

That area is now a lemon. The GFS goes wild with it but the Euro is far more lukewarm.

Gabby on its way to becoming our next hurricane