GaWx Posted Wednesday at 10:45 PM Share Posted Wednesday at 10:45 PM Though 8/4-10 dropped likely partially related to little support for the current MDR AEW, today’s Euro Weeklies are slightly more ominous than yesterday’s for August’s ACE as a whole: % of 2005-24 averages: 8/4-10: 80% (slightly lower than yest.) 8/11-17: 190% (slightly higher than yest.) 8/18-24: 210% (much higher than yest.) 8/25-31: 110% (same as yest.) Taken as a whole, these probably imply a prog of ~38 ACE for next month fwiw. Please don’t shoot the innocent messenger! Link to comment Share on other sites More sharing options...
Boston Bulldog Posted Wednesday at 11:44 PM Share Posted Wednesday at 11:44 PM 1 hour ago, GaWx said: Good news regarding microwave scans: Amazing news. SSMIS and similar polar-orbiting scans aren’t perfect, but they are the best Hurricane inner core analysis tool outside of in-situ observations and radar. 1 1 1 Link to comment Share on other sites More sharing options...
GaWx Posted Thursday at 12:55 AM Share Posted Thursday at 12:55 AM The UKMET is back to having a TD form on the 0Z. But unlike yesterday’s 0Z, which developed the current central MDR wave that was moving NNW to threaten the SE US, this one forms on an old front just off the SE US coast. After forming, it crawls NNE to just offshore the Mid-Atlantic coast remaining as a TD: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 90 HOURS FORECAST POSITION AT T+ 90 : 32.0N 75.3W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 04.08.2025 96 31.4N 75.7W 1010 29 1200UTC 04.08.2025 108 32.1N 74.8W 1012 25 0000UTC 05.08.2025 120 32.1N 75.0W 1013 25 1200UTC 05.08.2025 132 33.1N 73.9W 1015 23 0000UTC 06.08.2025 144 34.3N 73.9W 1015 23 1200UTC 06.08.2025 156 35.7N 73.6W 1014 30 0000UTC 07.08.2025 168 37.6N 73.0W 1012 28 *Edit: 0Z Euro is a bit similar to 0Z UKMET but with just a very weak sfc low rather than a TD. It similarly goes up the US E coast just offshore and toward Cape Cod and Maine. Link to comment Share on other sites More sharing options...
GaWx Posted Thursday at 12:43 PM Share Posted Thursday at 12:43 PM For the 2nd run in a row, the UKMET (12Z) has a TD from off the SE US from a frontal zone with no notable strengthening and with very slow movement. This run has it initially moving NE/NNE before turning to the WSW and then SW a couple hundred miles off NC: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 66 HOURS FORECAST POSITION AT T+ 66 : 32.9N 73.5W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 03.08.2025 72 32.7N 72.9W 1010 26 0000UTC 04.08.2025 84 33.1N 71.9W 1009 26 1200UTC 04.08.2025 96 33.9N 70.8W 1010 29 0000UTC 05.08.2025 108 34.3N 70.4W 1012 27 1200UTC 05.08.2025 120 35.1N 69.4W 1014 30 0000UTC 06.08.2025 132 35.8N 69.2W 1014 31 1200UTC 06.08.2025 144 36.4N 69.1W 1015 30 0000UTC 07.08.2025 156 36.0N 69.8W 1015 31 1200UTC 07.08.2025 168 35.5N 70.4W 1016 29 1 1 Link to comment Share on other sites More sharing options...
GaWx Posted Thursday at 04:30 PM Share Posted Thursday at 04:30 PM August ACE forecast: Today’s Euro Weeklies vs yesterday’s (using 2005-24 base) 8/4-10: 0.9 vs 0.8 8/11-17: 1.5 vs 1.9 8/18-24: 1.6 vs 2.1 8/25-31: 1.2 vs 1.1 Overall, I’d call this slightly less active than yesterday’s run but still a good bit more active than 2005-24 average ACE for August as a whole. 1 Link to comment Share on other sites More sharing options...
Floydbuster Posted Friday at 03:32 AM Share Posted Friday at 03:32 AM I think things may turn on the next couple of weeks in the Atlantic. The long range ensembles look nasty, some showing hurricane landfalls in the Gulf or Florida east coast, and the wind shear is looking more and more favorable. This could all culminate during a positive phase of the MJO. 1 Link to comment Share on other sites More sharing options...
GaWx Posted Friday at 12:36 PM Share Posted Friday at 12:36 PM For the first time this season, the latest UKMET (12Z) has a TC in the MDR (moving WNW): NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 120 HOURS FORECAST POSITION AT T+120 : 10.3N 40.8W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 06.08.2025 120 10.3N 40.8W 1013 25 0000UTC 07.08.2025 132 11.4N 42.4W 1012 25 1200UTC 07.08.2025 144 13.0N 44.1W 1012 26 0000UTC 08.08.2025 156 14.8N 46.7W 1012 28 1200UTC 08.08.2025 168 16.1N 50.7W 1011 27 1 Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted Friday at 03:17 PM Author Share Posted Friday at 03:17 PM this possibly could be the E storm based on the ECMWF probability models Link to comment Share on other sites More sharing options...
GaWx Posted Friday at 03:19 PM Share Posted Friday at 03:19 PM Based loosely on the 12Z Euro/UKMET/GEFS, the 6Z/0Z GEFS, the 0Z/12Z EPS, yesterday’s Euro Weeklies, and the forecasted MJO, it appears to me that there’s a somewhat enhanced chance of a TS/H threat around the NE Caribbean ~8/9-10, around the Bahamas/FL ~8/12-13, and either the US Gulf coast or the US E coast ~8/14-16. This isn’t an explicit forecast but rather just notable hints of what may be to come for those areas. It could easily look very different as early as tomorrow. 12Z EPS is somewhat ominous/more active for the Bahamas/CONUS vs the 0Z EPS during Aug 12-16. *Potential* mid August threat from NE Caribbean to CONUS as it appears now: *Edit: I’m counting 50% of 12Z EPS members with a TC from this AEW. That’s quite high from this far out for the often rather conservative EPS. In addition, there are 5 TC members from the followup AEW threatening the NE Caribbean to Bahamas. 1 1 Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted Friday at 03:23 PM Author Share Posted Friday at 03:23 PM SAINT LEZAK HAS SPOKEN Tropical Development Windows Are ApproachingTwo Key LRC Predictions Are Already in the Forecast The next three weeks mark a critical transition in the tropics. As Saharan dust slowly retreats and the thunderstorm activity increases over the open Atlantic, Gulf, and Caribbean Sea, we are forecasting a much more favorable environment for tropical development. In fact, two of our key LRC-based tropical windows—predicted months ago—are expected to show up soon. These are not random guesses. These are precise forecast targets based on storm energy identified last fallthat is now cycling back through the pattern. As you’ll see in the graphic below, the timing and placement of these systems align directly with the Weather 20/20 LRC predictions that have been part of our Tropical Outlook Guide since spring. We’ll continue to track these windows closely in our daily updates and highlight what’s coming next a week from now in our early August Tropical Update next Saturday. Conclusion: A Quiet Start, But a Pattern-Driven Storm Season Awaits While the hurricane season has begun on a quiet note, we are not fooled by the calm—and you shouldn’t be either. The Saharan dust outbreaks and persistent summer anticyclone have done their job suppressing early activity, but the LRC tells a deeper story. We’re entering a new phase now—one where multiple tropical windows, renewed storm energy, and shifting jet stream dynamics begin to align. As we’ve shown throughout this report, the pattern is right on schedule. https://weather2020.substack.com/p/tropics-stay-quiet-impacts-from-saharan 1 Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted Friday at 03:25 PM Author Share Posted Friday at 03:25 PM 5 minutes ago, GaWx said: Based loosely on the 12Z Euro/UKMET/GEFS, the 6Z/0Z GEFS, the 0Z/12Z EPS, yesterday’s Euro Weeklies, and the forecasted MJO, it appears to me that there’s a somewhat enhanced chance of a TS/H threat around the NE Caribbean ~8/9-10, around the Bahamas/FL ~8/12-13, and either the US Gulf coast or the US E coast ~8/14-16. This isn’t an explicit forecast but rather just notable hints of what may be to come for those areas. It could easily look very different as early as tomorrow. 12Z EPS is somewhat ominous/more active for the Bahamas/CONUS vs the 0Z EPS during Aug 12-16. *Potential* mid August threat from NE Caribbean to CONUS as it appears now: How many NS are predicting for august chap? Link to comment Share on other sites More sharing options...
GaWx Posted Friday at 03:35 PM Share Posted Friday at 03:35 PM 10 minutes ago, BarryStantonGBP said: How many NS are predicting for august chap? Fwiw, I predicted 5 August NS (vs active era avg of 4) in the basin based mainly on the last few days of active Euro Weeklies along with MJO. 1 Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted Friday at 03:49 PM Author Share Posted Friday at 03:49 PM 17 minutes ago, GaWx said: Fwiw, I predicted 5 August NS (vs active era avg of 4) in the basin based mainly on the last few days of active Euro Weeklies along with MJO. I used the Euro models (weeklies/sub-seasonal range forecast) and somehow came up with: Dexter: 8-10 Aug, NW Gulf, C1 Erin: 12 - 16 Aug, EC FL swell, MDR, brush, C3 Fernand: 19 - 24 Aug, gyre NE Gulf, TS Gabs: 27 Aug - 2 Sep, Caribbean - NE Gulf, C2 Humberto: wait until September (or the very last day of August, probably CV long track), C4 I personally see 4 NS just based on the Euros alone Thoughts? Quote What to watch 8–10 Aug: quick Gulf spin-up (Dexter) under a brief shear lull. 12–16 Aug: MDR wave with hot SSTs + low shear → Erin RI signature (tight core, explosive 24–36 h). 19–24 Aug: weak vortex parked N Gulf; rain footprints instead of wind headlines (Fernand). 27 Aug–3 Sep: monsoon-gyre or Caribbean seed into central Gulf; steady strengthening. N Gulf impacts likely (Gabrielle). 5–15 Sep: African wave train + favorable MJO → Humberto’s Cape-Verde catwalk. Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted Friday at 03:55 PM Author Share Posted Friday at 03:55 PM 6 minutes ago, BarryStantonGBP said: I used the Euro models (weeklies/sub-seasonal range forecast) and somehow came up with: Dexter: 8-10 Aug, NW Gulf, C1 Erin: 12 - 16 Aug, EC FL swell, MDR, brush, C3 Fernand: 19 - 24 Aug, gyre NE Gulf, TS Gabs: 27 Aug - 2 Sep, Caribbean - NE Gulf, C2 Humberto: wait until September (or the very last day of August, probably CV long track), C4 I personally see 4 NS just based on the Euros alone Thoughts? TomballEd points out the possible "Erin" Link to comment Share on other sites More sharing options...
GaWx Posted Friday at 04:20 PM Share Posted Friday at 04:20 PM 52 minutes ago, BarryStantonGBP said: I used the Euro models (weeklies/sub-seasonal range forecast) and somehow came up with: Dexter: 8-10 Aug, NW Gulf, C1 Erin: 12 - 16 Aug, EC FL swell, MDR, brush, C3 Fernand: 19 - 24 Aug, gyre NE Gulf, TS Gabs: 27 Aug - 2 Sep, Caribbean - NE Gulf, C2 Humberto: wait until September (or the very last day of August, probably CV long track), C4 I personally see 4 NS just based on the Euros alone Thoughts? I just saw the new Euro Weeklies and am sticking with 5 NS. They are notably active again for mid to late August. 1 Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted Friday at 05:28 PM Author Share Posted Friday at 05:28 PM 1 hour ago, GaWx said: I just saw the new Euro Weeklies and am sticking with 5 NS. They are notably active again for mid to late August. Thoughts on how I mapped how each NS might go? Anything you’d change? Link to comment Share on other sites More sharing options...
GaWx Posted Friday at 05:33 PM Share Posted Friday at 05:33 PM 2 minutes ago, BarryStantonGBP said: Thoughts on how I mapped how each NS might go? Anything you’d change? That’s too detailed for me. So, I’ll leave those month long details to you. The only thing I’m saying is to watch for a midmonth TS/H NE Car to US. 1 1 Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted Friday at 06:15 PM Author Share Posted Friday at 06:15 PM 42 minutes ago, GaWx said: That’s too detailed for me. So, I’ll leave those month long details to you. The only thing I’m saying is to watch for a midmonth TS/H NE Car to US. I translated them into NS 1 Link to comment Share on other sites More sharing options...
GaWx Posted yesterday at 12:11 AM Share Posted yesterday at 12:11 AM 0Z UKMET NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 156 HOURS FORECAST POSITION AT T+156 : 16.9N 48.9W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 08.08.2025 156 16.9N 48.9W 1012 25 0000UTC 09.08.2025 168 18.4N 51.5W 1012 26 Link to comment Share on other sites More sharing options...
WxWatcher007 Posted yesterday at 02:56 AM Share Posted yesterday at 02:56 AM I still think 1-2 TCs before August 20, but I’m increasingly bullish for my peak season forecast (again). 1 Link to comment Share on other sites More sharing options...
GaWx Posted yesterday at 12:19 PM Share Posted yesterday at 12:19 PM 12z UK: 3rd run in row w/MDR TD moving WNWNEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 114 HOURSFORECAST POSITION AT T+114 : 13.8N 41.9WLEAD CENTRAL MAXIMUM WINDVERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)-------------- ---- -------- ------------- -------------1200UTC 07.08.2025 120 14.4N 43.3W 1009 280000UTC 08.08.2025 132 16.2N 46.1W 1009 291200UTC 08.08.2025 144 17.6N 49.2W 1010 280000UTC 09.08.2025 156 19.7N 52.0W 1011 281200UTC 09.08.2025 168 21.2N 55.3W 1011 34 2 Link to comment Share on other sites More sharing options...
GaWx Posted 16 hours ago Share Posted 16 hours ago Invest 95L has been designated for the area off of NC, which may actually be just one of two potential systems to develop off of NC this week (the 2nd potential one is what the 18Z gfs went gaga with):Tropical Weather OutlookNWS National Hurricane Center Miami FL200 AM EDT Sun Aug 3 2025For the North Atlantic...Caribbean Sea and the Gulf of America:1. Western Atlantic (AL95):A non-tropical area of low pressure located along a frontal boundary about 180 miles off the coast of North Carolina is producing disorganized showers and thunderstorms. Environmental conditions are marginally favorable for this system to potentially become a tropical or subtropical depression or storm today or on Monday while it moves east-northeastward at about 10 mph, away from the coast of North Carolina. Environmental conditions become less conducive for development after Monday. For additional information, including gale warnings, please see High Seas Forecasts issued by the National Weather Service.* Formation chance through 48 hours...medium...40 percent.* Formation chance through 7 days...medium...40 percent.2. Central Tropical Atlantic:A tropical wave is forecast to move off the west coast of Africa in the next day or two. Environmental conditions could support some gradual development of the wave during the middle to latter part of next week while it moves generally west-northwestward across the central tropical Atlantic.* Formation chance through 48 hours...low...near 0 percent.* Formation chance through 7 days...low...20 percent. ——————— Meanwhile, the latest Euro Weeklies continue to suggest that quite an active August is favored. 1 Link to comment Share on other sites More sharing options...
Silver Meteor Posted 12 hours ago Share Posted 12 hours ago Area Forecast Discussion National Weather Service Newport/Morehead City NC 426 AM EDT Sun Aug 3 2025 Mid to late-week, the upper level pattern will begin to change as troughing develops over the TN Valley, and as ridging sets up from the western Atlantic north through eastern Canada. During this time, medium range guidance is showing a pretty good signal for a blocky pattern to develop across the eastern U.S. and western Atlantic. Of note, medium range deterministic and ensemble guidance suggest the Atlantic may begin to "wake up" so to speak as we move into the latter half of the week. While the main development region (MDR) will be a potential candidate for tropical activity, it is also worth noting that guidance is beginning to show a signal closer to home for low pressure development along the frontal boundary off the Southeast U.S. coast later in the week. As we often remind folks this time of year, please be careful not to lock into one run of one model, as significant run-to-run changes can be expected. At this point, the main takeaway is to be aware of the potential. Stay tuned for updates from the National Hurricane Center through the week in case this risk were to increase. Link to comment Share on other sites More sharing options...
NorthHillsWx Posted 12 hours ago Share Posted 12 hours ago Starting to see an uptick on models. Looks like two possible home grown systems then something from the MDR. August is here! 1 1 Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted 10 hours ago Author Share Posted 10 hours ago 1 hour ago, NorthHillsWx said: Starting to see an uptick on models. Looks like two possible home grown systems then something from the MDR. August is here! In which sequence do they form Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted 10 hours ago Author Share Posted 10 hours ago 5 hours ago, GaWx said: Invest 95L has been designated for the area off of NC, which may actually be just one of two potential systems to develop off of NC this week (the 2nd potential one is what the 18Z gfs went gaga with):Tropical Weather OutlookNWS National Hurricane Center Miami FL200 AM EDT Sun Aug 3 2025For the North Atlantic...Caribbean Sea and the Gulf of America:1. Western Atlantic (AL95):A non-tropical area of low pressure located along a frontal boundary about 180 miles off the coast of North Carolina is producing disorganized showers and thunderstorms. Environmental conditions are marginally favorable for this system to potentially become a tropical or subtropical depression or storm today or on Monday while it moves east-northeastward at about 10 mph, away from the coast of North Carolina. Environmental conditions become less conducive for development after Monday. For additional information, including gale warnings, please see High Seas Forecasts issued by the National Weather Service.* Formation chance through 48 hours...medium...40 percent.* Formation chance through 7 days...medium...40 percent.2. Central Tropical Atlantic:A tropical wave is forecast to move off the west coast of Africa in the next day or two. Environmental conditions could support some gradual development of the wave during the middle to latter part of next week while it moves generally west-northwestward across the central tropical Atlantic.* Formation chance through 48 hours...low...near 0 percent.* Formation chance through 7 days...low...20 percent. ——————— Meanwhile, the latest Euro Weeklies continue to suggest that quite an active August is favored. HA HA 1. Western Atlantic (AL95): A non-tropical area of low pressure located along a frontal boundary about 180 miles off the coast of North Carolina is producing disorganized showers and thunderstorms. Environmental conditions are marginally conducive for this system to become a tropical or subtropical depression or storm today or on Monday while it moves east-northeastward at about 10 mph, away from the coast of North Carolina. After Monday, environmental conditions become less conducive for development. For additional information, including gale warnings, please see High Seas Forecasts issued by the National Weather Service. * Formation chance through 48 hours...medium...50 percent. * Formation chance through 7 days...medium...50 percent. 2. Central Tropical Atlantic: A tropical wave is forecast to move off the west coast of Africa in the next day or two. Thereafter, some gradual development of the wave is possible during the middle to latter part of next week while it moves generally west-northwestward across the central tropical Atlantic. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 7 days...low...30 percent. Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted 10 hours ago Author Share Posted 10 hours ago 3 Link to comment Share on other sites More sharing options...
GaWx Posted 7 hours ago Share Posted 7 hours ago I just posted this elsewhere at this BB: The jury is obviously far from a decision for the 2025 season as a whole. Yes, YTD NATL ACE has been very low (1.5 vs 1951-2024 avg of ~9) through this morning with it at 64th highest out of the last 75 seasons. And being that low this far into the season does increase the chance for a quiet rest of season somewhat, which I’d love to see for a change. And yes, there are two new areas in the EPAC that may develop this week. However: 1. The EPAC is currently still at only 28 ACE vs a normal of 47 meaning it’s now ranked at only 39 of the last 55 seasons. 2. We have weak La Ninalike conditions, which are typically conducive for an active rest of season. 3. The following other relatively quiet through now NATL seasons (under 5 ACE vs normal of 9) were active the rest of the season: Season: Total season’s NATL ACE 1969: 148 and that was El Niño (don’t have EPAC pre-1971); only 1 storm as of now (not an H) with 17 others still to come and not til Aug 10th+ 2017: 225 and EPAC was then way up at 74 (12/54); no H yet with 10 H/6 MH still to come Aug 7th+ 2019: 132 and EPAC ACE was then up at 45; only 2 storms as of now with 16 more to come and not til Aug 20th+ 1980: 148 1999: 176; only 1 storm through now (not an H) with 11 others to come and not til Aug 18th+ including 5 MH 2004: 227 and that was El Niño; only 2 storms through now with 13 more to come Aug 9th+ including 9H/6 MH 1998: 181 and EPAC was then up at 55 (14/54); only one storm as of now (not an H) with 13 more to come, including 10 H and not til Aug 19+ 1955: 158 (don’t have EPAC pre-1971); only 2 storms through now (no H yet) with 9H/4 MH still to come 1967: 125 (don’t have EPAC pre-1971); only 1 storm as of now with 12 more to come and not til Aug 28+ From this list: 1969, 2017, 2019, 2004, and 1998 should especially get one’s attention. 4. The Euro Weeklies, which overall did well last year with its several week out predictions, have been forecasting an active August for the last 5 days. 5. The various ensemble runs have been active both in the MDR as well as off of NC. The current TWO is already highlighting two areas. 6. The MJO is headed for phases 1 and 2, two often active phases during August. ——————— Edit: In summary, whereas the very low ACE as of this morning is typically a slightly bearish indicator the rest of the season as a whole, my points 1-6, above, suggest that an active rest of the season is at the very least still a reasonable possibility and may actually still be favored. 1 1 1 Link to comment Share on other sites More sharing options...
WxWatcher007 Posted 5 hours ago Share Posted 5 hours ago We finally have stuff worth talking about. 5 minutes ago, WxWatcher007 said: Tropical Overview 8/3 Things have been quiet for most of the season despite three named storms so far. ACE is well below normal, but at this point in the season ACE doesn't really mean much. We have approximately 90% of the season to go, and the peak of the season, which begins around August 20, is right around the corner. There are several factors that have contributed to the quiet start. In recent high activity/hyperactive years, we've seen activity in the tropical Atlantic before climatology makes the region favorable. Think Beryl of last year. That was not the case this year, as a hostile atmospheric pattern, stability, and lower sea surface temperature anomalies (SSTAs) have left the tropical Atlantic devoid of activity, even in the face of historically low Saharan Air Layer intrusions (SAL) during its usual annual peak. Meanwhile, the PAC has been hot. And continues to be so as a favorable phase of the MJO passes through the region. Before more favorable atmospheric conditions move into the Atlantic we are already seeing homebrew starting to percolate off the East Coast. With a favorable MJO in the coming weeks, the window will begin to crack open in the Atlantic. At this time I am tracking three distinct possibilities. (As I wrote this the NHC designated area two as a lemon and area three as an orange) 1. Invest 95L Off the Southeast Coast The first area of interest is already likely in the early TC genesis stage. A current non-tropical low is trying to detach from a frontal boundary off the southeast coast, and is looking more and more like it's trying to become tropical with persistent convection firing now near an apparent center of circulation. This is a very common way to get TC genesis in the homebrew region this time of year. This looks well on its way to developing before conditions become more hostile early in the week. It is not a threat to land, as these frontal system TCs tend to follow the weakness in the trough out to sea. It's interesting, but not overwhelmingly so. 2. "Follow up" Development off Southeast Coast Now this one is much more interesting, and has been for a while now. Yesterday most probably sat up as the happy hour GFS showed a strong system attempt to develop in the wake of 95L off the same frontal boundary, this time getting shunted back into the US. Well, although that run of the GFS was way too aggressive, the signal for some sort of follow up development has been on the guidance for a few days now. It's not terribly hard to see why, as the environment looks at least marginally favorable for some development. Vorticity First--again, the frontal boundary is usually good for getting some vorticity spin up. So if something is far enough off the coast there should be some sort of spin that develops in the coming days. Both models pick up on this in the medium range. This is not enough for TC genesis. Which leads to the second favorable factor. Instability While the tropical Atlantic has been incredibly stable so far this season... There has been no such issue off the East Coast...in fact, instability has been extremely high. What that tells me is that anything that does have spin and can develop an area of low pressure will have a chance to generate convection, which will only help with TC genesis odds as long as the system isn't hugging land the entire time. SSTa Not much analysis needed here. I expect the the southwest Atlantic to be a hotbed of activity this season because that's where the heat is. Any low is going to have a shot with enough time and space to become tropical in this SSTa regime. Shear The key inhibitor here is shear. Often times with these frontal boundary systems near the coast you have shear and drier air that is lurking. That comes with the territory with the frontal boundary. Here it is unclear how favorable a shear environment this potential system will find, but guidance is hinting at a window of lower shear later this week taking hold. What makes this particularly interesting is the steering pattern. While the outcome is different in terms of where the area of vorticity goes, the pattern evolution is the same. In the wake of 95L a ridge builds in and traps whatever could develop along the coast. That's something to legitimately watch. Maybe not closely, yet, but at least with a casual eye. 3. Central Atlantic Wave This final area is highlighted as a lemon (now orange) by the NHC, but the wave hasn't yet left the coast of Africa. This is an area that should benefit from the coming MJO change, and it already has a few things going for it. First, as I mentioned earlier, SAL is at historic lows. Now, that doesn't mean that SAL isn't out in the Atlantic, because it is, but look at the coast of Africa. When this wave comes off, it will likely be in a pocket where there is very little SAL. It will be fighting stability in that part of the basin along with lesser SST anomalies, but that can be manageable with a vigorous enough wave. Timing and location are everything, and this one is still TBD on both. With the steering pattern likely changing with a ridge taking over, if this is able to get trapped under the ridge it will likely be moving into the most favorable conditions for a tropical wave yet this season. Just a little off and it's staying well out to sea. To be sure, I'm not calling for a US threat or anything at this time, but the NHC has a large geographical zone for development for a reason. There is higher than usual uncertainty on where this could develop. This may be our first reasonably strong system of the year for two reasons. First, it is running into the aforementioned warm SW Atlantic. OHC is primed for a system ready to take advantage of it. Even the central Atlantic looks conducive for some strong activity again this year. Second, and potentially far more concerning, is the ensemble guidance that wants to totally wipe out unfavorable shear. This is a fairly stunning retreat of shear by the 00z EPS. So while I'm not necessarily expecting a super burst of activity, we now have plenty to track in advance of the start of peak season, with two areas that are worth watching... 3 1 Link to comment Share on other sites More sharing options...
BarryStantonGBP Posted 4 hours ago Author Share Posted 4 hours ago Google Weather Lab: Cyclones (3rd August 2025 edition, goes up to 18th August 2025) NOTE: ALL NAMES ARE IN "SPEECH MARKS" FOR ILLUSTRATIVE PURPOSES ONLY: 95L ("Dexter"): "Erin" - remains weak, curves OTS after FL landfall: "Fernand" - likely from the "African Wave" that's currently 0/40, early recurve, but Bermuda may need to keep an eye out for this one: "Gabrielle" - from an AEW that makes a beeline for Central America: "Humberto" - straight for PR, Cuba, Bahamas: Link to comment Share on other sites More sharing options...
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