GaWx

12Z Euro little later landfall vs 0Z and quite a bit stronger

Hurricane Easy in 1950 (first landfall Cedar Key) produced a 6.5 foot TB surge, the largest since the 10.5 feet of 1921. At that landfall, Easy was a 958 mb cat 3 with 120 mph highest winds and was just crawling. Since 1950, highest surge I could find was 5 feet from H Gladys in 1968. It was a 100 mph cat 2 at landfall, which was 60 miles N of Tampa moving NE

With 12Z Euro still remaining, three 12Z runs shifted left vs their respective 0Z runs (UKMET, ICON, and the already tied for most left at 0Z run GFS) and one shifted right (the tied for furthest left at 0Z run CMC).

12Z UKMET landfalls ~65 miles to the NW (at Apalachee Bay) of 0Z, which was ~30 miles NW of Cedar Key

12Z UKMET significant shift left. First, here was 0Z UKMET: TROPICAL STORM IDALIA ANALYSED POSITION : 19.8N 85.5W ATCF IDENTIFIER : AL102023 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 28.08.2023 0 19.8N 85.5W 997 38 1200UTC 28.08.2023 12 20.8N 84.8W 996 41 0000UTC 29.08.2023 24 22.2N 85.5W 996 39 1200UTC 29.08.2023 36 23.6N 85.1W 996 46 0000UTC 30.08.2023 48 25.7N 85.1W 993 50 1200UTC 30.08.2023 60 28.6N 83.9W 989 51 0000UTC 31.08.2023 72 31.4N 81.8W 988 47 1200UTC 31.08.2023 84 33.3N 78.1W 987 45 0000UTC 01.09.2023 96 34.0N 73.6W 989 52 1200UTC 01.09.2023 108 34.8N 70.3W 990 54 0000UTC 02.09.2023 120 35.5N 67.8W 991 49 1200UTC 02.09.2023 132 36.3N 65.8W 990 47 0000UTC 03.09.2023 144 37.2N 63.7W 984 53 1200UTC 03.09.2023 156 39.5N 60.7W 974 54 0000UTC 04.09.2023 168 41.4N 57.5W 971 50 ------------------ To compare, here is the 12Z UKMET showing a significant shift left: TROPICAL STORM IDALIA ANALYSED POSITION : 20.6N 85.4W ATCF IDENTIFIER : AL102023 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 28.08.2023 0 20.6N 85.4W 995 41 0000UTC 29.08.2023 12 21.5N 85.4W 995 46 1200UTC 29.08.2023 24 23.3N 85.8W 995 43 0000UTC 30.08.2023 36 25.3N 86.0W 994 45 1200UTC 30.08.2023 48 27.7N 85.3W 992 48 0000UTC 31.08.2023 60 30.2N 84.1W 987 42 1200UTC 31.08.2023 72 32.6N 81.8W 992 43 0000UTC 01.09.2023 84 33.6N 78.7W 998 38 1200UTC 01.09.2023 96 34.5N 75.3W 1001 46 0000UTC 02.09.2023 108 34.0N 72.7W 1004 44 1200UTC 02.09.2023 120 34.9N 70.4W 1005 44 0000UTC 03.09.2023 132 37.0N 66.5W 1003 33 1200UTC 03.09.2023 144 36.8N 64.9W 1000 48 0000UTC 04.09.2023 156 37.2N 62.1W 995 44 1200UTC 04.09.2023 168 38.9N 59.8W 988 47

Below is a copy of a post I did 10/1/22 detailing Ian FL LF progs for 5 main op models starting from 0Z 9/25 runs, which were then 85 hours out from the Port Charlotte LF. As of 0Z today, Idalia was only ~60 hours from landfall. So, that would about correspond to the 0Z 9/26 runs for Ian. So, one can see from this that: A. -Top performing UKMET <50 miles from actual Ian LF all runs within 85 hours. ~Spot on for runs that were 85, 61, 49, and 13 hours out with little net bias. -2nd best ICON even had Tampa (70 miles too far left) just 49 hours out -CMC was still way too far left just 25 hrs out! -GFS not close til 25 hrs out -Euro not close til 37 hrs out B. Per 0Z 9/26 Ian runs, which correspond to ~how far from LF is Idalia as of 0Z today (~60 hours): 1) UKMET was spot on and ICON only 25 miles too far left 2) CMC and GFS were way up at Apalachee Bay, a whopping 250 miles too far left 3) Euro was up at Cedar Key, 160 miles too far left 4) So, non-UKMET models were all too far left with GFS, CMC, and Euro a whopping 160-250 miles too far left 5) For Idalia, models are way closer together for LF at ~60 hour point (0Z 8/28 runs): -GFS/CMC furthest left near Perry -ICON furthest right ~10 miles SE of Cedar Key -So, range is only 75 miles vs 250 miles for Ian at same time from LF! GFS/CMC are furthest left like for Ian but not nearly by as much -UKMET/Euro right in middle ~30 miles NW of Cedar Key -Based on this, I'm guessing that 0Z GFS/CMC at Perry will verify too far left -My best guess is to go close to 0Z UKMET/Euro, which were ~30 miles NW of Cedar Key and ~40 miles NW of 0Z ICON --------------------------------- Here's the Ian FL landfall model performance post I made last year: "Looking back to the 0Z 9/25 runs at where the models had FL landfalls: 0Z 9/25: ICON Venice CMC Cedar Key GFS Destin Euro Sarasota UKMET Port Charlotte 12Z 9/25: ICON Sarasota CMC Apalachee Bay GFS Apalachee Bay Euro Tampa UKMET Venice 0Z 9/26: ICON Venice CMC Apalachee Bay GFS Apalachee Bay Euro Cedar Key UKMET Port Charlotte 12Z 9/26: ICON Tampa CMC Apalachicola GFS Tampa Euro Big Bend UKMET Port Charlotte 0Z 9/27: ICON Venice CMC Big Bend GFS Sarasota Euro Venice UKMET just N of Ft Myers 12Z 9/27: ICON Port Charlotte CMC Tampa GFS just N of Port Charlotte Euro Port Charlotte UKMET 20 miles S of Ft. Myers 0Z 9/28: ICON 15 miles S of Port Charlotte CMC Venice GFS Port Charlotte Euro Port Charlotte UKMET Port Charlotte My grades on FL landfall only (i.e., excluding SC landfall) for 9/25-8 runs: UKMET A- ICON B Euro C- GFS D CMC F"

Even though Cedar Key is 90 miles from Tampa, a strong cat 3 landfall like your first stab shows would I believe put Tampa Bay at risk for a 7-8 foot storm surge based on analogs. That would make it the highest surge there since 1921. Thus, that might seem overdone. But keep in mind that in 1950 on Sep 5, H Easy initially hit Cedar Key moving NE where it had a 958 mb/120 mph/cat 3 landfall. There was a 6.5 foot surge at Tampa Bay. Adding some for your slightly stronger 125 mph as well as you having it way up at 150 mph 24 hours earlier tells me that there'd probably be a risk of a bit higher than this analog's 6.5 foot surge. What's even more scary is that 2020's Eta was only a 50 mph TS when it, too, landfalled at Cedar Key (moving NNE like Idalia is projected to do) and it was able to produce a 4.2 foot surge at Tampa Bay! If a 50 mph TS centered up at Cedar Key can produce a 4.2 foot surge, I'd think that a 125 mph H centered in the same area could conceivably produce near double that. Then again, there may have been some highly unusual circumstances with Eta that won't be present with Idalia.

I'm becoming increasingly concerned down here for potential huge impacts if a worst case scenario of a major hurricane FL landfall and subsequent track too close to this area were to materialize. In that worst case scenario, it would likely be difficult to deal with due to complicating family circumstances (disability related). Not a pretty situation as it looks now for here Wednesday/Wednesday night: From NWS at CHS: WEDNESDAY: MUCH OF WEDNESDAY INTO WEDNESDAY NIGHT WILL BE DOMINATED BY IDALIA. 27/12Z GUIDANCE HAS SHIFTED EAST A BIT AND A TAD FASTER. THE LATEST NHC FORECAST SHOWS INCREASING PROBABILITIES FOR BOTH TROPICAL STORM AND HURRICANE CONDITIONS, BUT IT IS STILL TOO SOON TO TALK SPECIFICS WITH RESPECT TO DETERMINISTIC WINDS FOR THE LOCAL AREA. MUCH WILL BE DETERMINED ON HOW IDALIA RESPONDS TO CONDITIONS OVER THE EASTERN GULF OF MEXICO AND HOW IT TRACKS OVER NORTHERN FLORIDA. SUFFICE TO DAY, CONFIDENCE IS INCREASING THAT SOME DEGREE OF IMPACTS, POSSIBLY SIGNIFICANT, WILL OCCUR ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. IN ADDITION TO POSSIBLE TROPICAL STORM AND/OR HURRICANE CONDITIONS, HEAVY RAINFALL AND FLOODING WILL BECOME AN ISSUE, ESPECIALLY WITH ELEVATED HIGH TIDES EXPECTED AND A PRE POTENTIALLY ONGOING. THIS WILL ONLY ENHANCED THE RISK FOR FLASH FLOODING, ESPECIALLY AT THE COAST. THERE IS STILL PLENTY OF TIME TO PIN DOWN THE HEAVY RAIN, WIND AND TIDE FORECASTS, AND HOW THEY WILL INTERPLAY. EXPECT A VARIETY OF HYDROLOGIC, TROPICAL AND SURGE/COASTAL FLOODING HEADLINES WILL BE NEEDED AT SOME POINT, POSSIBLY AS EARLY AS MONDAY AFTERNOON.

I'm becoming increasingly concerned even up here for potential major impacts if a worst case scenario of a major hurricane FL landfall and subsequent track too close to this area were to materialize. In that worst case scenario, it would be difficult to deal with due to complicating family circumstances (disability related). Ugh

The record high Nino 4 per the monthly OISST table back to 1982 is 30.22 (Nov of 2015). The 2nd warmest Nino 4 is 29.84 and is a tie (Nov of 2009 and Dec of 2015). Aug of 2023 is projected to be ~29.64. But the warmest Aug, alone, is the 29.42 of 2015. So, that will be easily passed. It will be interesting to see what the Nino 4 peak will be. If I'm not mistaken, the warmest models (BoM, Euro, Meteo-France and JMA) have it getting to ~30.40-30.45. But the coolest (CFS and UKMET) only get it to ~29.80. Of course, the warming globe is a big factor in making attaining records easier in all regions. The record warmest for June and July were in 2015 with 2018 second and 2023, third.

Agreed 100%. I was just going further with that Tweet and excluding the Big Bend. In the stretch from Cedar Key south to just N of TB, a whopping ~15 (30%) of 12Z EPS members cross!

The 12Z UKMET was about same as 0Z with landfall closer to the center part of FL Big Bend (~50 miles NW of Cedar Key) moving NNE.

So, the 12Z EPS has 4 members out of 51 (8%) with a landfall south of the Big Bend and N of Tampa Bay, the most dangerous track for Tampa Bay. That's nothing to take lightly but there's lots of hope it won't happen as the odds are quite low based on this.

Regarding that Tweet assuming he is excluding both the Big Bend and Tampa, themselves, when he says "between", it would be extremely difficult though not impossible for Idalia to cross the coast in that stretch because most guidance shows it still moving NNE at that latitude and that part of the coast is angled NNE. October, when headings are more commonly NE to E, is usually a more dangerous period for that to happen.

Indeed, Hermine was a solid H with 981 mb near landfall in the Big Bend. Beware of inaccurate Tweets. He even shows Hermine landfalling into the upper part of the Big Bend! If he means "between exclusive" instead of "between inclusive", then that's different. But "between exclusive" would be just a rather short portion of the coast centered on Spring Hill at a difficult angle to have a landfall. In that case, I don't think there's even been a TS crossing since 1968 (excluding 1968, itself, which had Gladys).

It is just JB looking at ONE cold run of a terrible model even though the last 12 averaged out show slightly warmer than normal. He's not going to show mild runs, of course. Also, JB said nothing nor showed anything addressing snow in his tweet. This is what he said: "what a CFSV2 run for JFM. whats interesting is it has a correlation to our chief analogs. Cold tries to come in November, December opposite of last year is warm then the hammer comes down. Gotta to migrate the warmest water into enso 3.4 for winter. ( Migrating Modoki)" -------------- Now just because JB does this all of the time doesn't mean he can't be right this time as a broken clock is right twice a day. As someone who enjoys winter, I hope he's right even though in most years that he's hyped a cold winter he hasn't done well. Here in the SE US and up into the Mid-Atlantic states, El Niño on average gives the best shot at a cold winter. One coming right after La Niña, especially more than one year's worth, probably helps even more. We're looking at a possible record breaking rise of the ONI from the prior year's La Niña low point, a huge shake up which I hope is a mechanism that leads to drastic changes in the upcoming winter vs last winter.

Euro landfalls in SE portion of Big Bend near 980 mb. It is significantly stronger and a bit further SE than recent runs. It then goes offshore 50 miles S of Savannah (mid-GA coast).

The average of the last 3 days of CFS runs for JFM isn't cold fwiw (I have no idea about snow as the maps don't show it). For hype purposes, he likes to post ONE run at a time when it has BN temps even though the CFS is a terrible model because that's how JB does things (just about all of us know this though): JFM precip: mainly near normal fwiw

Fwiw since the CFS is not a good model out just one month much less 4-6 months out, here's the CFS 2m temp anomaly (C) forecast for DJF based on the last 3 days/12 runs using 1984-2009 as base climo: (aside: Nino 3.4 SSTa peaks in Nov): Precip anomalies for DJF:

12Z UKMET: about same as 0Z with landfall NW part of FL Big Bend moving NNE followed by turn to NE/ENE going through south central and then SE GA. Then it goes offshore near CHS, SC: TROPICAL DEPRESSION 10L ANALYSED POSITION : 19.8N 86.1W ATCF IDENTIFIER : AL102023 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 27.08.2023 0 19.8N 86.1W 1003 24 0000UTC 28.08.2023 12 20.4N 85.3W 1001 29 1200UTC 28.08.2023 24 21.4N 85.5W 1001 33 0000UTC 29.08.2023 36 22.6N 85.8W 1001 36 1200UTC 29.08.2023 48 24.2N 86.1W 1000 34 0000UTC 30.08.2023 60 25.8N 85.5W 999 38 1200UTC 30.08.2023 72 28.6N 84.6W 995 49 0000UTC 31.08.2023 84 31.2N 82.7W 993 39 1200UTC 31.08.2023 96 33.2N 78.8W 993 43 0000UTC 01.09.2023 108 33.4N 75.0W 995 48 1200UTC 01.09.2023 120 33.8N 72.0W 999 46 0000UTC 02.09.2023 132 33.2N 69.2W 1001 43 1200UTC 02.09.2023 144 32.8N 68.4W 1003 37 0000UTC 03.09.2023 156 33.6N 65.9W 1003 35 1200UTC 03.09.2023 168 33.6N 64.5W 999 47

This is the strongest Euro yet as others were in low 990s at landfall and is very near the 0Z UKMET landfall point. This would be a big mess for the Big Bend wind-wise and especially storm surge-wise in this very vulnerable high poverty area as was discussed earlier ITT.

0Z UKMET: ~40 mile E shift at LF into NW FL Big Bend vs E Panhandle on 12Z run; once inland sharper turn to go offshore SC vs 12Z going over Augusta and then staying inland through SC into much of NC TROPICAL DEPRESSION 10L ANALYSED POSITION : 21.0N 85.5W ATCF IDENTIFIER : AL102023 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 27.08.2023 0 21.0N 85.5W 1004 25 1200UTC 27.08.2023 12 20.3N 85.6W 1002 27 0000UTC 28.08.2023 24 20.6N 85.3W 999 32 1200UTC 28.08.2023 36 21.7N 85.5W 999 35 0000UTC 29.08.2023 48 22.8N 85.5W 1000 38 1200UTC 29.08.2023 60 24.5N 85.6W 1000 41 0000UTC 30.08.2023 72 26.5N 85.3W 998 39 1200UTC 30.08.2023 84 29.2N 84.1W 995 45 0000UTC 31.08.2023 96 31.9N 81.8W 992 42 1200UTC 31.08.2023 108 33.6N 77.7W 991 43 0000UTC 01.09.2023 120 34.4N 73.4W 992 56 1200UTC 01.09.2023 132 34.4N 69.0W 996 52 0000UTC 02.09.2023 144 33.2N 65.7W 1000 45 1200UTC 02.09.2023 156 33.6N 63.2W 999 43 0000UTC 03.09.2023 168 33.5N 60.3W 997 48

I'm currently projecting an August ERSST 3.4 SSTa of ~+1.35. Looking at the 25 El Niño seasons since 1950, the average/median rise from Aug to peak month was 0.53/0.59 but the variation is huge from a mere .01 in 1987 and .06 in 2004 to a very large 1.09 in 1991, 1.17 in 2009, and 1.39 in 1982. To get a super ONI peak, I'd think that getting a single month peak of +2.15 would likely be enough. That would require a rise from Aug of 0.80. Only 6 of the 25 did that. Regardless, I'm expecting 2023 to be the 7th as of now based on strong model agreement. But we'll see.

DMIN

3.4 per OISST is now +1.6, which implies ERSST is likely +1.5+. It has warmed nearly 0.3 over just the last 9 days, the fastest warming since the rapid late May/early June warmup. Through June and July, combined, when the SOI averaged ~neutral much of the time, it warmed only 0.4. But Aug has already warmed 0.5 as the SOI (often a leading indicator) has been mainly negative the last 6 weeks. Based on this graph, Monday's update should be at +1.5. Aug MTD has risen to just over +1.3. With the recent rapid rise Aug OISST is headed toward ~+1.4, implying Aug ERSST of ~~+1.35. An Aug ERSST of +1.35 would make 2023 near 1957, just behind 1972's +1.40, and much warmer than 1982's +0.98 and especially 2009's mere +0.56. But it would be quite a bit cooler than 1965's +1.66 and especially 1997's/2015's +1.91/+1.93. So, Aug of 2023 looks to be near tied with 1957 for 4th warmest for ONI. Now, RONI is a different story.