GaWx

The 12Z UKMET has Dexter eventually becoming a minimal 988 mb H on Thursday though that’s an outlier right now:TROPICAL STORM DEXTER ANALYSED POSITION : 35.0N 67.5WATCF IDENTIFIER : AL042025LEAD CENTRAL MAXIMUM WINDVERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)-------------- ---- -------- ------------- -------------1200UTC 04.08.2025 0 35.0N 67.5W 1005 360000UTC 05.08.2025 12 36.3N 65.9W 1008 351200UTC 05.08.2025 24 37.8N 63.9W 1010 340000UTC 06.08.2025 36 39.2N 62.3W 1008 431200UTC 06.08.2025 48 39.5N 59.8W 1007 410000UTC 07.08.2025 60 40.3N 56.0W 1003 391200UTC 07.08.2025 72 41.2N 51.3W 993 540000UTC 08.08.2025 84 43.2N 46.2W 988 651200UTC 08.08.2025 96 45.0N 42.6W 985 480000UTC 09.08.2025 108 46.0N 36.8W 993 401200UTC 09.08.2025 120 47.2N 29.8W 999 360000UTC 10.08.2025 132 CEASED TRACKING

From the maps available at the link below, I looked at the 50 Jul-Aug-Sep maps for each season 1975-2024 and counted the days. It took ~2 hours to count it accurately, but it was well worth the time so I could figure out how statistically significant the 39% of MH hitting during phase 2 really is. There are 4,508 days Jul-Sep 1975-2024 excluding 1978, which for some reason is blank. I counted 756 of those 4,508 days (16.8%) to be when it was in phase 2 (outside or inside circle). I rounded that up to 17%. The 16.8% is ~1 in 6 days rather than 1 in 8 days. That’s because there’s been somewhat of a tendency for the MJO to be longer in phase 2 in July-Sept vs the average of the other 7 phases for whatever reason. But even so, 1/6 is nowhere close to 39% as it is only 43% of it. Thus, I consider this to be a pretty strong signal for phase 2 http://www.bom.gov.au/climate/mjo/#tabs=Monitoring

The concern I have that there may actually be something threatening somewhere in the Conus (Gulf or Atlantic coasts) (hopefully not!) as we approach midmonth is increased because the model consensus is suggesting there may be an extended period of the MJO being in or near phase 2 around then. Why would a long period in phase 2 be a concern? US MH hits during phase 2 (**either inside or outside the circle**) during July-Sep since 1975: -Ida (2021) -Harvey (2017) -Irma (2017) -Ivan (2004) -Bret (1999) -Emily (1993) -Hugo (1989) -Frederic (1979) -Eloise (1975) That’s 9 of 23 (39%) of Jul-Sep Conus MH hits during 1975-2024 having occurred just during phase 2, alone! The 39% is more than double the ~17% of days in phase 2, meaning a significant/non-random signal for increased danger. Latest MJO forecasts: GEFS suggests long period in phase 2 (it’s mainly inside circle phase 2, which unfortunately is almost equally as high risk as outside): EPS is similar Maybe that’s why avg Jul-Sep precip is heaviest during phase 2 (this is for both inside and outside circle):

Here was a post I made elsewhere on 1/7/2018 about it being the coldest 7 days in my area since Jan of 1977: SAV just experienced its coldest 7 consecutive days in 41 years, its first below 32 F week in 28 years, and a tie for its 8th coldest since records started in the 1870s! The longevity of this cold is one for the ages. 10 SAV weeks at or colder than 32 F starting from coldest: - 1/1886 - 12/1917-1/1918 - 2/1895 - 1/1977 & 1/1970 tied - 2/1899 - 1/1887 - 1/2018 & 12/1901 tied - 12/1989 Only 4 of these 10 weeks have occurred during the last 100 years! By the way, the snow & ice remain largely intact in shady areas and we're over 4 days after it ended! I still have one icicle! 1/8/18 edit: Note that this long duration cold occurred despite a +NAO. It was supported by a +PNA/-EPO combo as well as a -AO when averaged out.

Upped from 20% to 30%: 2. Off the Southeastern United States: A broad area of low pressure is forecast to form in a couple of days a few hundred miles off the coast of the southeastern United States. Some gradual development of this system is possible during the middle or latter part of the week as the system drifts to the west or northwest. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 7 days...low...30 percent.

Upped from 40% to 50%: Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 AM EDT Mon Aug 4 2025 For the North Atlantic...Caribbean Sea and the Gulf of America: Active Systems: The National Hurricane Center is issuing advisories on newly formed Tropical Storm Dexter, located over the western Atlantic Ocean. 1. Central Tropical Atlantic: A tropical wave is forecast to move off the west coast of Africa later today. Thereafter, some gradual development of the wave is possible, and a tropical depression could form late this 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...medium...50 percent.

We’re getting pretty heavy rains at 1AM (8/4) from an area moving only slowly NW. Hopefully, the heavy doesn’t last too long. Edit: It’s not yet letting up at almost 1:30. And this was released at 1AM, a repeat of Saturday: Z.000000T0000Z.000000T0000Z.OO/ CHATHAM GA- 101 AM EDT MON AUG 4 2025 ..FLOOD ADVISORY IN EFFECT UNTIL 3 AM EDT EARLY THIS MORNING * WHAT...FLOODING CAUSED BY EXCESSIVE RAINFALL IS EXPECTED. * WHERE...A PORTION OF SOUTHEAST GEORGIA, INCLUDING THE FOLLOWING COUNTY, CHATHAM. * WHEN...UNTIL 300 AM EDT. * IMPACTS...MINOR FLOODING IN LOW-LYING AND POOR DRAINAGE AREAS. WATER OVER ROADWAYS. OVERFLOWING POOR DRAINAGE AREAS. PONDING OF WATER IN URBAN OR OTHER AREAS IS OCCURRING OR IS IMMINENT. * ADDITIONAL DETAILS... - AT 100 AM EDT, DOPPLER RADAR INDICATED HEAVY RAIN EXTENDING FROM SILK HOPE AND HUNTER ARMY AIRFIELD TO RIO VISTA. A QUICK 1 TO 2.5 INCHES OF RAIN COULD FALL THROUGH 3 AM, RESULTING IN URBAN FLOODING. - SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... POOLER, MIDTOWN SAVANNAH, WINDSOR FOREST, HUNTER ARMY AIRFIELD, COFFEE BLUFF, DOWNTOWN SAVANNAH, HUTCHINSON ISLAND, WILMINGTON ISLAND, I-16/I-95 INTERCHANGE AND MONTGOMERY. Edit: I ended up with ~2” last night, which brings me up to a whopping 4.6” for just Aug 1-3! No garage flooding fortunately as it has been spread out just enough. This is reminding me of the very wet July 9-13 of this summer and makes my area vulnerable to flooding should we get more heavy rain this week. Edit: PRELIMINARY LOCAL STORM REPORT NATIONAL WEATHER SERVICE CHARLESTON SC 953 AM EDT MON AUG 04 2025 .TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON .DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE. ..REMARKS.. 0143 AM FLOOD 2 SW SAVANNAH 32.04N 81.11W 08/04/2025 CHATHAM GA EMERGENCY MNGR EMERGENCY MANAGER REPORTED THAT PORTIONS OF PAULSEN STREET AND ABERCORN STREET WERE CLOSED DUE TO FLOODING. ALSO, STALLED VEHICLES WERE REPORTED AT THE INTERSECTION OF 61ST STREET/ABERCORN STREET, 65TH STREET/ABERCORN STREET, AND 52ND STREET/MONTGOMERY STREET.

After 5 runs in a row with TCG from this (3 in MDR and the last 2 N of the MDR), the new UKMET (0Z) completely dropped this as a TC. Edit: the 12Z of 8/4 also failed to develop this. 2nd in a row.

The July 30 mb QBO was released today at -19.99 (nothing surprising).

Even though dews are still in the low 70s keeping it humid (so still sweating when the wind isn’t blowing), the steady NE winds along with overcast and only 81F near got me to take my first outside walk since early June I think. What’s interesting is that the winds off the 86F/30C ocean are not cooling winds. Right now they’re the opposite!

After the prior 3 full UKMET runs showed an MDR TD this week per their textual output, the last 2 runs for the record haven’t had it fwiw. The last two runs instead develop it well north of the MDR. This is from the latest (12Z): NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 156 HOURS FORECAST POSITION AT T+156 : 30.8N 50.0W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 10.08.2025 156 30.8N 50.0W 1016 27 1200UTC 10.08.2025 168 34.2N 49.9W 1016 28 —————————— Edit: Whereas the odds of it getting all of the way to the Conus are almost always not high if it actually becomes a TS well out in the MDR at this far out stage, the concern I have is that the MJO may then get stuck in phase 2. That has by a significant margin been the MJO phase (whether inside or outside the circle) when the most (major) hurricanes have hit the Conus during the months July-Sept. for the period 1975-2024 compared to any other single stage. So, even if this one fails to threaten, there may be others to watch. I hope to post more about that later. Regardless, it’s still very early and there’s no need to get overly worried. The risk to the US may actually be higher if it were to stay weak E of the Caribbean.

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.

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. ————- 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.

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.

We’re about to get a big hit it appears with heavy rain and much CTG lightning. BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE CHARLESTON SC 443 PM EDT SAT AUG 2 2025 THE NATIONAL WEATHER SERVICE IN CHARLESTON HAS ISSUED A * FLASH FLOOD WARNING FOR... CHATHAM COUNTY IN SOUTHEASTERN GEORGIA... * UNTIL 645 PM EDT. * AT 443 PM EDT, DOPPLER RADAR INDICATED A NEARLY STATIONARY AREA OF THUNDERSTORMS OVER WINDSOR FOREST AND HUNTER ARMY AIRFIELD. AS MUCH AS 2.5 INCHES OF RAIN HAS FALLEN OVER THE PAST HOUR AND ADDITIONAL 1 TO 3 INCHES COULD FALL THROUGH 645 PM, RESULTING IN CONSIDERABLE URBAN FLOODING. PREPARE NOW FOR POSSIBLE CLOSED ROADS DUE TO FLOODING. HAZARD...FLASH FLOODING CAUSED BY THUNDERSTORMS. SOURCE...RADAR INDICATED. IMPACT...FLASH FLOODING OF SMALL CREEKS AND STREAMS, URBAN AREAS, HIGHWAYS, STREETS AND UNDERPASSES AS WELL AS OTHER POOR DRAINAGE AND LOW-LYING AREAS. * SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE... WINDSOR FOREST, HUNTER ARMY AIRFIELD, COFFEE BLUFF, MIDTOWN SAVANNAH, DOWNTOWN SAVANNAH, MONTGOMERY, GARDEN CITY, THUNDERBOLT AND VERNONBURG. *Edit: I ended up with ~1.6” from late yesterday afternoon through very early this morning.

Yes due largely to collisions with seabreeze along with high moisture levels. I’m talking about my home, which is not as far inland as the airport and thus gets slightly more on avg…see darker shading nearer to coast. Our area gets avg summer rain that’s double+ avg winter rain. July/Aug are our 2 rainiest on avg. Normal July rain:

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

AAM finally going - (Ninaish):

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

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 just saw the new Euro Weeklies and am sticking with 5 NS. They are notably active again for mid to late August.

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.

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.

An east west band of scattered thunderstorms, some heavy, has popped up from W of my area to offshore. I started hearing thunder a little while ago and now it is raining at varying intensities. Edit: I ended with ~1” for the day, which I think is the heaviest since July 13th.

Thanks. In case you didn’t see it, the map says it is vs 1991-2020 climatology.