GaWx

12Z runs for TW SW of CV Islands: -GFS/CMC TS+ Lesser Antilles ~7/1; so CMC stronger than 0Z and similar to yesterday’s 12Z -ICON stronger low than 0Z/borderline TD? -UKMET still no TC through 168 -GEFS still rather active Eastern Tropical Atlantic: A tropical wave located a few hundred miles southwest of the Cabo Verde Islands is producing disorganized showers and thunderstorms. Some development is possible during the next several days, and a tropical depression could form over the tropical Atlantic by the end of the week or this weekend while the system moves westward at 15 to 20 mph. * Formation chance through 48 hours...low...near 10 percent. * Formation chance through 7 days...medium...40 percent.

Check this out for something fascinating at Augusta, GA (Bush): -noon was 93 with a dewpoint of 76 on a SE wind at 9 -1PM was 99 with a dewpoint way down at 58 on a SW wind at 13 gusting to 22!! That’s a heck of a boundary, a dry line of sorts that went through Augusta last hour! And it came in on SW winds!

Check this out CC and others for something fascinating at Augusta, GA (Bush): -noon was 93 with a dewpoint of 76 on a SE wind at 9 -1PM was 99 with a dewpoint way down at 58 on a SW wind at 13 gusting to 22!! That’s a heck of a boundary that went through there last hour, a dry line of sorts! And the drier air came in on SW winds!

But there’s no official downtown Atlanta station to see how hot downtown will be. So, we’ll never know what their actual will be. There hasn’t been an official downtown station there in many decades.

Regarding this map with forecasted highs: -Atlanta’s official station is the airport, not downtown. It is near the perimeter. Unfortunately, downtown doesn’t have an official station, which would be where the UHI center is typically strongest obviously. So, if the official Atlanta high were to be 98 as this map is forecasting, downtown could easily be over 100 if the winds are light enough. We’ll never know. -Atlanta has higher elevation than Dalton/Thomaston by 300 feet, Rome/Athens/Madison by 400 feet, Macon/Sandersville by 600 ft, and Columbus/Dublin by 800 ft.

For wave in E Atlantic, main 0Z Models: -GFS is by far its strongest run yet as it has a 975-7 mb H hitting the Windward Islands on July 1st, which then weakens and later dissipates in the Caribbean -CMC just has a weak low vs 12Z’s TS -ICON just has a weak low similar to 12Z -UKMET doesn’t have a TC just like the 12Z -GEFS is about as active as the 18Z. These last two runs are the strongest runs yet at the Lesser Antilles July 1-2 -0Z Euro is a bit more active than prior run with a defined LLC E of the Lesser Antilles though it is still a weak low (doesn’t look strong enough for TD imo) and then it dissipates as it enters the Caribbean TWO upped from 20% to 30% thru day 7: 2. Eastern Tropical Atlantic: A tropical wave centered a few hundred miles south-southwest of the Cabo Verde Islands is producing disorganized showers and thunderstorms. Some slow development of this system is possible late this week into early next week while it moves generally westward across the central and western tropical Atlantic at 15 to 20 mph. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 7 days...low...30 percent.

The HRRR maps being analyzed are for 3PM tomorrow (6/26), not today. I’ll compare them after then to see how they did. But indeed, low dewpoints and high heat were there today as you said. Will dewpoints be low enough and temps high enough tomorrow for the comparison? We’ll see!

1. The SE Caribbean tropical wave has just been designated as Invest 94L fwiw. 2. The 12Z GEFS/GEPS have a rather strong signal for a TC impacting the Lesser Antilles ~7/1-3. 3. The 12Z Euro has no TC unlike the prior two runs. Edit: But 12Z EPS is most active run yet.

The 12Z UKMET has nothing classified as a TC through the end of the run (day 7).

It appears to me that the new runs (12Z GFS and CMC) are developing what is already just offshore Africa. They both have a TS in the Windward Islands on Mon July 1st. If these happen to be right, the Atlantic will get a 2nd TS by July 1st.

Today’s SOI as expected per models has already gone positive from the strong negatives of just 2-3 days ago. It will rise quite a bit more in the coming days per model progs of Tahiti/Darwin SLP with Tahiti’s SLP going well above normal for June. It looks to peak near the 1017.5-1018 mb range on June 28th.

From what I saw elsewhere there’s a wave that is progged to move off Africa on Thursday that has some potential for development in the MDR per latest model consensus. Meanwhile, look how quiet it has been to this point relative to normal in the Pacific and N Indian (a mere 20%) despite the overall oceans’ near record warmth:

Here is the 6Z HRRR temperature map for 19Z (3PM EDT) tomorrow showing many non-mountain/non-coastal locations of VA/NC/SC/GA 101-104: Here is the 6Z HRRR dewpoint map for the same hour showing the same locations with 43-58 dewpoints: Comparing to NWS forecasts, these HRRR temperatures are several degrees hotter and dewpoints are significantly cooler. The HRRR dewpoints of 43-48 in the Charlotte, NC, to Macon/Columbus, GA, corridor look especially way too low. I’ll compare to reality tomorrow to see how well this HRRR run ends up verifying in these 4 states’ non-mountain/non-coastal locations with temperatures/dewpoints. I expect this run will verify with temperatures several degrees too hot most locations and dewpoints significantly too cool most locations.

The much wetter pattern vs last year at the same time has been helping immensely with keeping Key West and vicinity SSTs significantly lower. Last year June 10-24 KW buoy water averaged an astounding ~32C/89.6F thanks to the combo of drier than normal/near constant sunshine during the day/GW. This year that same period has averaged just under 30C/86.0F to the great relief of the coral. Key West Buoy data: https://www.ndbc.noaa.gov/data/realtime2/KYWF1.txt

This post is related to my prior post by showing a great example of afternoon summer hot/low dewpoint bias on the short term GFS here in the SE. The GFS from just 2 days earlier had these 2m temperature progs as of 18Z (2PM EDT) today: What verified? In SC, the 2PM temperatures are here: https://kamala.cod.edu/offs/KCAE/2406241810.asus42.CAE.html So, the SC 2PM temperatures included: CAE 96 vs GFS’ 102 and FLO 94 vs GFS’ 102. All actuals of major stations were 91-97 vs GFS range of 95-102. The GFS averaged a ~5 too hot on a run from just 48 hours earlier. In GA, the 2PM temperatures are here: https://kamala.cod.edu/offs/KFFC/2406241810.asus42.FFC.html So, the GA 2PM temperatures included ATL 93 vs GFS’ 97, AGS 95 vs GFS’ 99, and SSI 95 vs GFS’ 100. Hottest in GA at major stations was 97 vs GFS’ hottest of 101. So, the GFS averaged ~4-5 too hot from just 48 hours earlier. These summer 2PM misses of 4-5+ too high are common down here. I said above that I thought it was related to too low dewpoints. The GFS from just 2 days earlier had these 2m dewpoint progs as of 18Z (2PM EDT) today: The actual 2PM dewpoints were these: CAE 68 vs GFS’ 61, FLO 72 vs GFS’ 65, ATL 64 vs GFS’ 54, and AGS 71 vs GFS’ 60. So, dewpoints were 7-11 too low. This combo of too hot temperatures and too low dewpoints on sunny summer afternoons is very common on the GFS in the short term at the very least down in the SE US. @donsutherland1@bluewave@chubbs@ChescoWx

At least down here in the SE, I’ve seen on many occasions the GFS having unrealistically high temperatures in summer just a couple of days out. This has been occurring for a good number of years. There does seem to be a warm bias for summer highs on both models when skies are mainly sunny with the GFS seemingly being worse down here. I suspect it is related to daytime dewpoints being too cool thus lowering RHs too much and allowing for more rapid warming than reality. That being said, the heat indices may not be as far off.

Bumping this to show I made a mistake this morning by thinking today’s weekly update had 0.0 in Nino 3.4. I thought it was odd considering the graph of OISST dailies showing warming. What happened was that I was looking at last week’s update thinking it was today’s update. In reality, today’s update was a warming to +0.3 vs last week’s 0.0. (As one can see, I corrected the original post.) That makes much more sense.

Whether “appropriate” reporting or not, #1 on MSM outlets is always the almighty $ and the ratings that lead to more $. Nothing new in that regard. Online MSM wants more views. TV MSM wants more viewers. If you were in the biz, wouldn’t you want more viewers? I’d think I would. One of the best ways to get more views/viewers is to sensationalize/make the news/wx seem more interesting and a bigger deal than it really is. Remember when “Breaking News” really was a big deal? Not so much anymore since it occurs on a regular basis now. How about Joe Bastardi with his tendency to predict cold winters much more often than warm ones (though some of that is also likely due to his weenieism)? How many clicks is he going to get regularly if he predicts a warm winter? (which he has hardly ever done in the NE US) Was this sensationalized? It wouldn’t surprise me but I haven’t analyzed it. Don would know more.

I can’t find 50 mb back to 1948. Do you have a preference between 30 and 50? Do you feel there’s more forecasting value in seeing both?

Here’s back to 1948 at 30 mb: https://psl.noaa.gov/data/correlation/qbo.data

*Correction of my error: Weekly cpc update: rise from 0.0 to +0.3 in Nino 3.4 https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

I’m assuming this is meaningless as far as forecast value for the meat of the season (i.e., not at all “season cancel”) and we did have a close call with Invest 92L off GA, but I imagine it could imply a little something for the total # of NS this season (perhaps shave off 1 NS) in a season with extremely high numbers of NS being forecasted. Total # of NS through July 1st (excluding NS before May 1): 2024: ? (1 so far) 2023: 3 2022: 3 2021: 5 2020: 4 2019: 1 2018: 1 2017: 2 2016: 3 2015: 2 2014: 1 2013: 2 2012: 4 2011: 1 2010: 1 2009: 0 2008: 1 2007: 2 2006: 1 2005: 2 2004: 0 2003: 1 2002: 0 2001: 1 2000: 0 1999: 1 1998: 0 1997: 2 1996: 1 1995: 1 AVG 1995-2023: 1.5 Any thoughts? Even if there are no more NS by Jul 1st, 2024 is only 1/2 a NS behind the 1995-2023 avg and we just missed already having 2.

So, these two sources pretty much have opposite signals. This tells me to be skeptical about the idea of any significant relationship (enough for forecast value) between the solar cycle and ENSO. There may be a relationship, but what is it and how strong? Also, I’m noting that this 2nd source is older (from 2009) fwiw.

New BoM, which was way too warm last year: virtually unchanged from prior several months of runs. I think of it as very strongly warm biased, but feel even models like this are of some use by following their trends and they can be bias corrected. The latest is at 0.0 for OND. RONI would very likely be at least a few tenths cooler. It has June at +0.4 and July at +0.3, both of which I expect will verify too warm (especially July).

The recent SOIs probably aren’t that big of a deal except that perhaps one MAY think there’s no imminent big plunge of Nino 3.4 SST anomalies likely. But we’ll see what the projected upcoming E wind does as far as upwelling/cooling as that can easily lead to quick cooling. The 30 day SOI is at -5. Not Earth-shatteringly negative by any means but stronger La Niña immediately following El Niño often has a +SOI June preceding them: For La Niña since 1876-7 with a dip to -1.0 or lower (using RONI for 1949-50+) immediately following El Nino here was the preceding June SOI: 1886: +4 1889: +18 1924: +7 1942: +7 1970: +9 1973: +10 1983: -3 1988: -4 1998: +8 2007: +5 2010: +1 2016: +4 AVG: +6 - 7 of 12 June SOI + - 5 of 12 June SOI neutral (+4 to -4). - None -5 or lower The June SOI MTD has averaged -9.4. However, this will rise substantially by the EOM per models (consistent with upcoming E winds) and full June 2024 SOI may get pretty close to 0 as there are some large +SOIs likely on the way. The -9 MTD SOI has been due solely to well above normal Darwin SLP MTD (way up at 1014.1 mb) as its counterpart, Tahiti SLP, has NOT been averaging low (its 1014.0 mb avg is slightly above avg). Based on current progs June 2024 Darwin SLP will drop some to ~1013.5 mb, which compares to longtime avg of ~1012.7 mb. (Tahiti SLP is projected to rise to ~1014.7) Since 1933, these years had a June Darwin SLP of 1013.5+: 1940, 41, 49, 65, 77, 82, 88, 93, 97, 2004, 11, 17, 18, 19 - Looking at 14 years (before 2024) with June Darwin SOI of 1013.5+: 1940-1, 65, 77, 82, 97, 04, 18: El Nino 1993, 2019: neutral 1949, 88, 2011, 17: La Nina So, with 4 of these being La Niña, having a June ‘24 Darwin SLP of 1013.5 doesn’t tell me the chances of La Niña are small. To the contrary, 1988 had a Darwin SLP way up at 1013.9 and it still lead to one of the strongest La Niñas on record. And like 2024 it immediately followed a substantial El Niño.