GaWx

New (Oct) Euro precip anomaly forecast for DJF: very slightly wetter in NE/SE and very slightly drier part of Midwest vs Sept outlook and similar to Oct ‘24 outlook for last winter/La Ninaish NN much of E US but BN signal deep SE with lack of dominant ST jet Sept ‘25 outlook for DJF: Last Oct precip for last winter:

More (2M temps) from brand new Euro winter outlook: Oct (brand new) is somewhat mild in much of US similar to Sept outlook with mainly ~2-3.5 F AN (vs 1993-2016 base) in much of the US and mainly ~2 F AN much of NE US and ~2.5-3 AN much of SE US with best chance closer to 1 AN N tier from Wash state to Lakes, where it cooled ~1F from Sept outlook: Sept outlook was similarly fairly mild in most of the US: For comparison, here was last Oct’s outlook for DJF 24-5: was actually slightly warmer in the NE and we know that verified to be much too warm most of US Actual DJF 2024-5: much colder than Oct Euro forecast! Was Oct ‘24 the warmest Oct. DJF forecast for the NE back to 2017? No, it actually was this one for 2020-1, which like 2024-5 verified to be significantly too warm most of US: Actual DJF 2020-1: significantly colder than Oct Euro forecast! @snowman19

Thanks for the reminder! Here are the last two runs of Euro DJF H5 maps to compare: October (just released): very La Ninaish…hopefully this will be wrong just like 2024-5 was! Most negative anomalies in N Hem west of Hudson Bay (Ninaish): September run for DJF: didn’t have as strong of an Aleutian ridge; E US ridge similar:

This is now Invest 95L: Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Sun Oct 5 2025 For the North Atlantic...Caribbean Sea and the Gulf of America: 1. Tropical Atlantic (AL95): A broad area of low pressure associated with a tropical wave continues to produce a large area of disorganized showers and thunderstorms several hundred miles south-southwest of the Cabo Verde Islands. Environmental conditions appear conducive for additional development of this system, and a tropical depression is likely to form this week as the system moves quickly across the central tropical Atlantic, approaching portions of the Leeward Islands by the latter part of this week. * Formation chance through 48 hours...medium...40 percent. * Formation chance through 7 days...high...70 percent. @bigtenfan

The latest Euro Weeklies are the most active yet in the W Caribbean for the week of 10/13-19 (if I were in the FL pen., especially S half, I’d be pretty concerned for midmonth): Forecast nearby TC probabilities: Forecasted anomalies vs 2005-24 climo: wow!

The latest Euro Weeklies are the most active yet in the W Caribbean for the week of 10/13-19 (if I were in the FL pen., especially S half, I’d be a bit concerned for midmonth): Forecast nearby TC probabilities: Anomalies vs 2005-24 climo: wow!

There will continue to be persistent moderate NE and then E winds during the upcoming few days followed by a freshening of them from the NE late week from a new surface high. In addition, there’s a full moon on Tue (10/7) and perigee on Wed (10/8). As a result of the moon, astronomical tides are progged to be the highest of 2025 so far Oct 7-10. Because these already quite high tides are going to combine with the current and upcoming week’s winds, as well as a stronger surge of NE winds Thu/Fri, there’s a possibility of major coastal flooding at/near high tide late this week in the corridor from CHS through GA. Those in or traveling to coastal areas late this week should keep up to date on this:From KCHS NWS:GUSTY NE WINDS RETURN THURSDAY INTO FRIDAY BEHIND THE FRONT - 25TH TO 75TH PERCENTILE REFLECTING A MOST LIKELY WIND SPEED ALONG THE COAST OF AROUND 20-30 MPH - TO END THE WORKWEEK, WHICH, IN ADDITION TO ALREADY ELEVATED TIDE LEVELS, COULD BRING A PERIOD OF VERY IMPACTFUL TIDAL FLOODING TO END THE WEEK. SEE COASTAL FLOODING SECTION FOR MORE.TIDES/COASTAL FLOODING ASTRONOMICAL TIDES WILL CONTINUE TO INCREASED THROUGH NEXT WEEK DUE TO THE UPCOMING FULL MOON (OCT 7) AND PERIGEE (OCT 8). THIS IN COMBINATION WITH THE ANTICIPATION OF CONTINUED NORTHEASTERLY FLOW WILL CAUSE THE POSSIBILITY OF COASTAL FLOODING TO BECOME MORE LIKELY ALONG THE ENTIRE COASTLINE, INCLUDING BOTH DOWNTOWN CHARLESTON AND FORT PULASKI. SALTWATER INUNDATION COULD THEN OCCUR DURING BOTH THE MORNING AND EVENING HIGH TIDE CYCLES DURING THIS TIME. ALTHOUGH THERE IS CONSIDERABLE UNCERTAINTY THIS FAR OUT, PERSISTENT FAVORABLE WINDS HAVE THE POTENTIAL TO PRODUCE UP TO MAJOR COASTAL FLOODING BY THE LATTER PART OF NEXT WEEK.

Not to minimize TS Chantal, which caused record 24 hour rainfall in some portions of C NC, but will 2025 get through the rest of this season with no Conus hurricane impact for the first season since 2015? The record longest streak with a hurricane impact is 13 seasons (1938-50). -Since 1851 there have been 34 (20%) seasons with no Conus H impact on record. Of these 34, these were only 6 during La Niña (1872, 1890, 1892, 1973, 2000, and 2010) vs a much higher 15 during El Niño, which is intuitive. The highest ACE of these 34 was 2010’s 165 (La Niña) followed by 1951’s 126 (El Nino). -Since 1851 there have been only 6 (3%) seasons with a first Conus H impact on record in Oct or later: all were in Oct and none of these 6 had a second one. None were during La Niña. The highest ACE of these 6 was 1853’s 76 followed by 2002’s 68. So, if 2025 were to join them, it would by a good margin have the highest ACE of this group and would be the first during La Niña: 1853 neutral: Oct 20th (GA) when center passing 40 miles off GA from TC 1st reported ~NW Bahamas 1923 El Nino: Oct 16th (LA) from TCG in the EPAC! 1946 neutral: Oct 7th (W FL pen.) from TCG in NW Caribbean 1968 El Niño: Oct 18th (W FL pen.) from TCG in SW Caribbean (Gladys) 1987 El Niño: Oct 12th (Keys/S FL) from TCG in SW Caribbean (Floyd) 2002 El Niño: Oct 3rd (LA) from TCG in C MDR (Lili)

I’m getting some light to moderate showers that are moving W from off the ocean. First rain of the month. The forecast is for scattered showers to continue to occur in the area through the remainder of the night and through tomorrow. There could be a few thunderstorms tomorrow afternoon.

Go to 1st post, choose edit, and then edit title.

18Z Icon has lemon as a TD near S FL and pumpkin as TS E of Leewards at 120: Edit for other 18Z: -GFS has a hurricane turn sharply 200 miles E of Leewards as it recurves -Euro is again very weak and has no TC through 144 ———Edit for 0Z 10/5 UKMET: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 102 HOURS FORECAST POSITION AT T+102 : 15.3N 57.6W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 09.10.2025 108 15.9N 59.3W 1009 33 0000UTC 10.10.2025 120 17.2N 61.9W 1007 34 1200UTC 10.10.2025 132 18.2N 64.5W 1007 34 0000UTC 11.10.2025 144 19.6N 66.7W 1005 41 1200UTC 11.10.2025 156 21.3N 68.0W 1003 44 0000UTC 12.10.2025 168 23.9N 68.4W 1000 48

How soon folks forget about Chantal, which caused record flooding in parts of NC. Also, Erin missed NC by only 200 miles and caused storm surge flooding as well as TS winds on OB. There have been many full years that had less impacts than 2025 on the E coast.

Oct 11-20 TCG W Car. climo says from a generalizing standpoint this far out that Keys/SW and S tip of FL would be at the most risk in US although each setup is unique:

Pumpkin: 12Z UKMET dropped the FL TC but still has this though it doesn’t form til 162, moving WNW to the SSW of Bermuda: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 162 HOURS FORECAST POSITION AT T+162 : 22.7N 67.7W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 11.10.2025 168 23.0N 68.5W 1009 24 ——————- 12Z Icon 933 mb at 180 but getting ready to recurve; SE US being partially protected by TS S FL from the lemon though would very likely recurve safely even without that since overall pattern shouldn't allow it to get close:

1. Humberto: the vast majority of all models never had it threaten the US 2. Imelda: -No UKMET or Icon had it hit the US and only one JMA did so. They were not only not schooled, they were the schoolers! -Several CMC had it hit as you implied. -A good # of GFS/Euro along with many ens members hit as you implied. -But some Euro AI runs hit, too, including from Humberto. So, UK, Icon, and JMA did better than Euro-AI: this top map has Humberto hit NC!

I’m in the SAV area. It’s pretty amazing how fast it has changed here. After ~17” of rain in August and water tables through the roof, I got only ~1” in Sept and see that the map you posted already has me in yellow.

For the pumpkin 0Z UK: similar to 12Z with the recurve NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 108 HOURS FORECAST POSITION AT T+108 : 15.2N 53.0W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 08.10.2025 108 15.2N 53.0W 1009 36 0000UTC 09.10.2025 120 17.2N 56.5W 1010 32 1200UTC 09.10.2025 132 19.0N 59.6W 1010 30 0000UTC 10.10.2025 144 20.1N 61.4W 1010 26 1200UTC 10.10.2025 156 21.4N 62.9W 1010 29 0000UTC 11.10.2025 168 23.2N 63.8W 1009 27

The UKMET (2nd run in a row) has the Bahamas lemon become a TC: The 0Z UKMET has itbecome a TD at 168, when it is in the NW Bahamas: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 168 HOURS FORECAST POSITION AT T+168 : 26.1N 77.8W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 11.10.2025 168 26.1N 77.8W 1007 33

Would it be possible, for continuity purposes, to incorporate it in the “two lemon” thread since most of the posts, including model output, are for the tropical ATL wave?

MJO is forecasted to continue to traverse mainly favorable phases meaning a resumption of activity fairly soon wouldn’t be surprising, especially with it being La Niña:

AAM forecast: Ninaish for at least most of month

ACE, which yesterday got to a NN 91.64, is now taking a break for awhile pending mainly what the E MDR system and any possible W Caribbean system will or won’t do next week (Bahamas AOI is very weak with only a 10% chance): note that it got to 29th out of the last 75. It just missed 2018 though it went ahead of 2024, 2016, and 2022 (2022 not shown because it was then 78.85). But, 2024 and 2016 should soon pull well ahead of 2025 during this expected 2025 respite: So, getting 100+ is still not yet certain even though it’s highly likely. I’ll give it a 95% chance since it’s La Nina and recent late seasons have been active.

12Z GEFS for pumpkin: only one of 30 hits Conus (hits S FL as a hurricane) and that’s because it is the furthest SW member (at Barbados) as it approaches the Lesser Antilles. The rest are at that time from PR to the Leewards (~50%) with ~50% at that time well NE of the Leewards: Here’s when that one member hits S FL. The one at the Outer Banks is from a NW Caribbean system: Edit: I don’t think any 12Z EPS are hitting the CONUS. If there are any, I can’t tell.

The 12Z Euro for the “pumpkin”: no TC til ~192 hours when it’s 1005 mb that’s ~125 miles N of PR. But it’s already recurving sharply then and never gets stronger than 1005 mb til it gets to 30N way out in the middle of the ocean. ———— 2PM TWO up to 0/50:2. Tropical Atlantic:A tropical wave has just emerged off the coast of Africa. The wave is forecast to interact with another disturbance over the eastern tropical Atlantic, and then move westward after that. Environmental conditions are expected to become conducive for some slow development of the system in a few days, and a tropical depression could form near or east of the Lesser Antilles by the end of next week.* Formation chance through 48 hours...low...near 0 percent.* Formation chance through 7 days...medium...50 percent.Forecaster Berg

Regarding the pumpkin: 12Z UKMET: 3rd in a row with TCG from this; similar TCG to prior run but moves NW instead of WNW and thus ends up further N than prior run although not quite as far N as two runs ago; Also this one has it become declassified at 168: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 126 HOURS FORECAST POSITION AT T+126 : 16.6N 54.6W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 09.10.2025 132 17.8N 56.3W 1009 36 1200UTC 09.10.2025 144 19.9N 59.3W 1010 30 0000UTC 10.10.2025 156 21.8N 61.2W 1009 29 1200UTC 10.10.2025 168 CEASED TRACKING