GaWx

Consistent with the prior 3 Euro runs, the 12Z yet again has a TS just off Africa that originates from an AEW that comes off ~9/11. But this time it comes off quite far north (near 20N) and thus easily recurves just offshore:

12Z UKMET: strongest yet (920mb!!) 250 miles E of Bermuda: HURRICANE LARRY ANALYSED POSITION : 14.5N 40.1W ATCF IDENTIFIER : AL122021 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 03.09.2021 0 14.5N 40.1W 982 55 0000UTC 04.09.2021 12 15.5N 42.7W 981 58 1200UTC 04.09.2021 24 16.7N 45.4W 982 55 0000UTC 05.09.2021 36 17.8N 47.6W 980 59 1200UTC 05.09.2021 48 19.4N 49.7W 976 63 0000UTC 06.09.2021 60 21.1N 51.5W 970 67 1200UTC 06.09.2021 72 22.4N 53.5W 960 73 0000UTC 07.09.2021 84 23.6N 55.1W 949 88 1200UTC 07.09.2021 96 25.0N 56.9W 946 94 0000UTC 08.09.2021 108 26.6N 58.3W 928 105 1200UTC 08.09.2021 120 28.8N 59.7W 927 105 0000UTC 09.09.2021 132 31.4N 60.7W 920 110 1200UTC 09.09.2021 144 34.4N 61.1W 922 107

Consistent with the above 12Z Euro and the run before that, the 0Z Euro still has a TS from an AEW coming off Africa on 9/11 with a strong high to its NNW: End of run:

0Z UKMET is again down to 922-3 mb and passes only 150 miles east of Bermuda then: HURRICANE LARRY ANALYSED POSITION : 13.9N 36.8W ATCF IDENTIFIER : AL122021 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 03.09.2021 0 13.9N 36.8W 988 50 1200UTC 03.09.2021 12 14.5N 40.3W 986 49 0000UTC 04.09.2021 24 15.5N 43.1W 983 54 1200UTC 04.09.2021 36 16.6N 45.8W 979 60 0000UTC 05.09.2021 48 18.0N 47.8W 972 64 1200UTC 05.09.2021 60 19.4N 49.9W 971 66 0000UTC 06.09.2021 72 20.8N 52.0W 961 72 1200UTC 06.09.2021 84 22.0N 53.8W 950 84 0000UTC 07.09.2021 96 23.3N 55.5W 936 100 1200UTC 07.09.2021 108 25.2N 57.6W 933 97 0000UTC 08.09.2021 120 27.2N 59.5W 927 103 1200UTC 08.09.2021 132 29.5N 61.4W 922 112 0000UTC 09.09.2021 144 32.5N 62.5W 923 111

12Z EPS continues with a lot of activity in the MDR during the 11-15 day period from various AEWs, which the US may have to monitor for after 9/20:

12Z EPS has many more members vs prior runs hitting or grazing E New England or Canada vs the 0Z:

12Z Euro, like the 0Z Euro, has a TS just off the coast of Africa 9/11. This is consistent with the EPS runs I’ve been posting. Note how strong the central Atlantic high is to the NNW of it. If that were to verify, this likely wouldn’t recurve early and may even soon after this start moving WSW for a period, which would be a warning signal as Yaakov ( @jconsor) and I have noted, especially with the La Nina(ish) ENSO:

12Z UKMET: down to 922 mb at the end! But again, very low US threat. Bermuda needs to watch closely. HURRICANE LARRY ANALYSED POSITION : 13.3N 33.3W ATCF IDENTIFIER : AL122021 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 02.09.2021 0 13.3N 33.3W 993 48 0000UTC 03.09.2021 12 13.8N 37.2W 988 50 1200UTC 03.09.2021 24 14.4N 40.5W 983 52 0000UTC 04.09.2021 36 15.3N 43.6W 977 62 1200UTC 04.09.2021 48 16.3N 46.2W 975 65 0000UTC 05.09.2021 60 17.6N 48.3W 971 65 1200UTC 05.09.2021 72 19.2N 50.6W 969 68 0000UTC 06.09.2021 84 20.9N 52.5W 960 77 1200UTC 06.09.2021 96 22.2N 54.4W 949 81 0000UTC 07.09.2021 108 23.6N 56.1W 941 97 1200UTC 07.09.2021 120 25.0N 57.8W 930 106 0000UTC 08.09.2021 132 27.3N 59.1W 922 107 1200UTC 08.09.2021 144 29.9N 60.0W 922 111

Larry has not moved S of due W between any two reference points. It moved due west between 8 AM and 2 PM yesterday and otherwise N of due W to WNW.

Still watching this timeframe as the 0Z EPS still has something coming off Africa ~9/11: End of the run:

0Z UKMET: down to 927 mb at the end pf the run! TROPICAL STORM LARRY ANALYSED POSITION : 12.5N 29.8W ATCF IDENTIFIER : AL122021 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 02.09.2021 0 12.5N 29.8W 1002 41 1200UTC 02.09.2021 12 13.0N 34.0W 996 45 0000UTC 03.09.2021 24 13.6N 37.5W 993 44 1200UTC 03.09.2021 36 14.2N 41.0W 989 49 0000UTC 04.09.2021 48 15.3N 44.1W 981 54 1200UTC 04.09.2021 60 16.7N 47.0W 974 65 0000UTC 05.09.2021 72 18.1N 49.5W 971 62 1200UTC 05.09.2021 84 19.8N 51.8W 972 64 0000UTC 06.09.2021 96 21.4N 53.5W 969 67 1200UTC 06.09.2021 108 22.8N 55.1W 965 64 0000UTC 07.09.2021 120 24.0N 56.5W 952 81 1200UTC 07.09.2021 132 25.3N 57.9W 939 101 0000UTC 08.09.2021 144 26.8N 58.5W 927 105

Great stuff. Actually, I happened to have studied eastern Atlantic WSW movers, myself, a while back and saved this list of the 12 that made US landfall (all but Carol of 1953 hit as a hurricane)(# in parentheses is days from African coast to US landfall): - #6 of 1893 (GA/SC) (14) - #4 of 1928 (FL)(11) - #4 of 1947 (FL, LA) (14) - Able of 1952 (SC) (13) - Carol of 1953 (ME grazed) (11) - Donna of 1960 (FL, NC, New England) (12) - Dora of 1964 (FL) (13) - Allen of 1980 (TX) (12) - Hugo of 1989 (SC) (12) - Fran of 1996 (NC) (14) - Isabel of 2003 (NC) (15) - Ivan of 2004 (AL/FL) (16)

Following up from yesterday: today's 12Z EPS has similar activity and may be the next AEW to watch closely in the CONUS for after 9/20:

I'm still not concerned about Larry to be, but am somewhat more interested in what may happen a bit afterward. Way out in cartoonland, the 12Z EPS has an AEW that moves off Africa ~9/11 with many members remaining pretty weak but more importantly moving briskly westward. This may be a sign that it would move much further west than Larry. With it being La Nina or close to it, the climo of AEW's like this one says they have a better chance to get into the western basin than for other ENSO. That climo also says that AEWs that come off Africa through mid Sept., especially during La Nina, still often get pretty far west. Even so, it wouldn't be til 9/21+ that it could reach the CONUS based on this 9/15 map:

Wow, the 3.4 Nino weekly anomaly released today for last week warmed a whopping 0.6 C from -0.9 to -0.3! Whereas I’m sticking with my moderate La Niña call, that much warming was quite the surprise for me and doesn’t exactly help my confidence. We’ll see what the next few weeks bring. Looking at records, an anomaly warming of 0.6+ in one week is rare though oddly enough 4 of the 5 occurrences over the last 31 years happened within just the last 2 years: 8/25/21 warmed 0.6 6/24/20 warmed 0.6 9/25/19 warmed 0.7 11/21/18 warmed 0.6 7/8/92 warmed 0.6 That's it for warmings of 0.6+ back to 1990!

N.O. and vicinity now has over 90% of customers without power:

Going rapidly downhill at N.O. (Ignore the 32 dewpoints). Intl Airport dropped 5 mb in the last hour and has 1/4 mile vis. There now is a whopping ~9 mb difference between there and Lakefront! N.O. INTL ARPT HVY RAIN 77 32 19 E56G83 29.01F VSB 1/4 N.O. DWNTWN HE RAIN 78 76 93 MISG N/A VSB 1 N.O. LAKEFRONT HVY RAIN 77 32 19 E46G71 29.27F VSB 1/2

Latest LA outage map shows ~2/3 of N.O. area out of power:

It continues to go downhill in New Orleans and the pressure gradient is now up to 6 mb over just a 15 mile distance! 5 PM CDT: N.O. INTL ARPT HVY RAIN 76 75 97 E48G74 29.16F VSB 1/2 N.O. DWNTWN HE HVY RAIN 77 75 93 E23G46 29.27F VSB 3/4 N.O. LAKEFRONT HVY RAIN 77 76 96 E54G78 29.34F VSB 1/2

The latest wobble due north is bad news for the New Orleans area, especially for Kenner and even Metairie. Keeping in mind how bad it got in 1965 with Betsy (which was about 12 mb weaker at landfall and on a similar path) and with Ida still holding quite strong, this isn't going to be pretty for that area.

So, there's now a 3.3 mb gradient in N.O. over the less than 15 miles from the international airport, which is closer to the projected path, to the lakefront station.

3 PM CDT N.O. stations show a continued increase in winds and rapid drop in pressure along with a continued very strong gradient reflected by the 0.10" difference between the airport and lakefront: CITY SKY/WX TMP DP RH WIND PRES REMARKS N.O. INTL ARPT RAIN 77 74 90 E46G67 29.37F FOG N.O. DWNTWN HE RAIN 77 74 90 E24G40 29.41F FOG N.O. LAKEFRONT HVY RAIN 77 75 93 E51G72 29.47F VSB 1/4

LA power outages are now 85-90% in darkest colored counties and already almost 50% N.O. area:

2PM CDT N.O. stations: rapid pressure falls continue and winds increasing at Lakefront. Also, note how tight the pressure gradient is based on the 3 mb/.09” difference between the airport and lakefront: CITY SKY/WX TMP DP RH WIND PRES REMARKS N.O. INTL ARPT RAIN 78 74 87 E36G59 29.43F FOG N.O. DWNTWN HE RAIN 78 74 87 NE12G35 29.47F FOG N.O. LAKEFRONT LGT RAIN 78 75 90 E53G66 29.52F FOG