GaWx

The 2PM TWO has it now up to 60% within 7 days. The earliest on record back to 1851 of a TS in the tropical Atlantic east of the Caribbean is June 19th, set by Bret in 2017. This could come close. Next earliest is June 24th-25th (1933). The third earliest is June 30th (Elsa of 2021). *Edit for correction: Elsa was 3rd earliest but it became a TS at 5AM AST on July 1st, not on June 30th. Elsa track is in here:

Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Fri Jun 16 2023 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: Eastern Tropical Atlantic: A tropical wave located between the west coast of Africa and the Cabo Verde Islands is producing disorganized showers and thunderstorms. Environmental conditions appear to be conducive for gradual development, and a tropical depression could form during the early to middle portions of next week while the system moves westward at 15 to 20 mph across the eastern and central tropical Atlantic. * Formation chance through 48 hours...low...10 percent. * Formation chance through 7 days...medium...50 percent. Forecaster Bucci

Due to the cooling that just ended, I'm back to thinking it is extremely unlikely the BoM's +1.2 for June will be reached.

Just 11 days ago, the EPS and GEFS both had an MJO forecast going through the entire MC phases 4 and 5 at moderate strength through about June 20th. Instead, the actual MJO only barely made it into moderate phase 4 and it already is within the circle. The June 5th forecasts had had it going into moderate phase 5 around today with a prog of about a 4-5 day period within moderate phase 5. I didn't at all expect this forecast failure as one can see below in my June 5th post:

That puts 2023 +160k vs the average of 2007-2022 and 6th highest of the last 17 years as of June 15th.

The cooling has ended with warming resumed in all three datasets: CDAS: warmed 0.013 to 0.697 Coral Reef Watch: warmed 0.018 to 0.890 OISSTv2.1: warmed 0.042 to 0.860 *Edited for typos

The 0Z Euro is the 3rd in a row with a closed tropical low in the MDR east of the LAs. This run has it the furthest south and is slightly stronger than the 12Z. It then goes WNW into the Caribbean to SW of PR. That would be a rarity for so early in the season. This Euro has a TD that looks close to making minimal TS strength as Bret (assuming 0Z GFS is wrong about its earlier W Caribbean system) that is similar to Bret of 2017. If that occurs, Bret of 2023 would be second only to Bret of 2017 as the earliest TS on record to go into the Caribbean from the east. From 8AM TWO: Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Thu Jun 15 2023 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: 1. Eastern Tropical Atlantic: A tropical wave is forecast to move off the west coast of Africa later today and early Friday. Environmental conditions are expected to be conducive for gradual development of this system while it moves generally westward to west-northwestward at 15 to 20 mph across the eastern and central tropical Atlantic during the early to middle part of next week. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 7 days...low...20 percent. Forecaster Bucci

Do you or does anyone else have any idea of how accurate the Euro ensemble has been and whether there's an identified bias looking ahead from summer to winter at H2 velocity potential?

We're really getting rocked here now, harder than the late morning activity. Very heavy rains, frequent lightning, and gusty winds are all occurring. This reminds me why I hate satellite dish vs cable!

My money's on uncertainty! This is a tough year to forecast. In the contest I'm going with the less active side vs 1995+, but with low confidence.

The 12Z Euro has what appears to be a TD on 6/21 that moves WNW to just NE of the Leewards on 6/23.

Slower cooling averaged out today of only 0.02 (day 5): CDAS: cooled 0.03 to 0.684 Coral Reef Watch: no change at 0.872 OISSTv2.1: cooled 0.03 to 0.818

June so far in this area has been very wet due to a good number of mainly afternoon and evening thunderstorms. Today is expected to be still another wet day with the possibility of severe thunderstorms near midday. There currently are severe thunderstorms well to our west: THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN LAURENS COUNTY IN CENTRAL GEORGIA... NORTHWESTERN TOOMBS COUNTY IN SOUTHEASTERN GEORGIA... SOUTHERN TREUTLEN COUNTY IN EAST CENTRAL GEORGIA... WHEELER COUNTY IN CENTRAL GEORGIA... MONTGOMERY COUNTY IN CENTRAL GEORGIA... * UNTIL 945 AM EDT. * AT 915 AM EDT, SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE EXTENDING FROM NEAR LOWERY TO NEAR CEDAR GROVE TO NEAR LITTLE OCMULGEE STATE PARK, MOVING EAST AT 50 MPH. HAZARD...60 MPH WIND GUSTS. SOURCE...RADAR INDICATED. IMPACT...EXPECT DAMAGE TO ROOFS, SIDING, AND TREES. * LOCATIONS IMPACTED INCLUDE... SOPERTON, ALAMO, MOUNT VERNON, VIDALIA, GLENWOOD, UVALDA, AILEY, HIGGSTON, ALSTON, TARRYTOWN, LOTHAIR, LANDSBURG, CEDAR GROVE, BARNHILL, KIBBEE, LITTLE OCMULGEE STATE PARK, JORDAN, LOWERY, CHARLOTTEVILLE AND ZAIDEE. @gtg947h may be affected within a couple of hours

I'm guessing that the Arctic ice has been helped by a cooler than normal period dominating the last 7 weeks: Edit: The only two Mays back to 1958 comparably cool to 2023 were 1964 and 2015 per these graphs.

Today shows another (4th) day of cooling in all 3 daily updated datasets that I've been following. 6/13/23 coolings: CDAS: 0.04 to 0.715 Coral Reef Watch: 0.03 to 0.872 OISSTv2.1: 0.04 to 0.845 Four day cooling from June 9th to 13th CDAS: 0.26 Coral Reef Watch: 0.20 OISSTv2.1: 0.19 Four days of cooling averaged over the three datasets: 0.07, 0.06, 0.04, 0.04

From what I've learned from others, that blocking ridge that Paul mentioned is leading to lighter trade winds, which is leading to record low for June Saharan dust being blown into the tropical Atlantic. That record low dust means the sun is better able to heat the ocean, which has apparently been a major factor in the record warm for June tropical Atlantic. https://michaelrlowry.substack.com/p/its-saharan-dust-season-but-wheres Related to this, I assume that clouds/rainfall in the tropical Atlantic have been below normal since that usually leads to AN SSTs during summer. So, I'm guessing that tropical wave activity has been BN for early June, which perhaps is consistent with lighter trades bringing off weaker waves from Africa? San Juan has had virtually no rain during the last 2 weeks.

For those who don't realize it, the 0.9 for 3.4 is for the prior calendar week, centered on June 7th. Meanwhile, the "correctional" cooling has gone into a 3rd day. I'm guessing that they're about to end: 6/10/23 coolings: CDAS 0.06 Coral Reef Watch: 0.08 OISSTv2.1: 0.08 6/11/23 coolings: CDAS 0.09 (to 0.825) Coral Reef Watch: 0.06 (to 0.935) OISSTv2.1: 0.04 (to 0.915) 6/12/23 coolings: CDAS: 0.07 (to 0.752) Coral Reef Watch: 0.03 (to 0.903) OISSTv2.1: 0.03 (to 0.888)

Credit to @TheClimateChanger alerting me to the record San Juan June 1-11th warmth via another thread, which I then incorporated in the following: Very likely related to the record warm tropical Atlantic and record low Saharan dust for this time of year, San Juan has just had its warmest June 1-11 on record, 86.9 F. Furthermore, it is the warmest by a good margin. The old record warmth was down at 85.3, set in 1988. The record coolest is 77.5, set in 1922, 1913, 1914, and 1939. https://www.weather.gov/wrh/Climate?wfo=sju They've had a mere 0.02" of rainfall so far this month, 1% of their normal of 1.87" for June 1-11.

The GFS streak has passed. GFS streak: 12Z June 5th, 2023-18Z June 11th, 2023 RIP It was 26 runs old. It had a pretty long life though not near a record breaker. This streak will always be remembered for its tenacity.

- KSAV in 2023: only 5 90+ days YTD through June 11th with hottest of 92 - Fewest # of 90+ days through June 11th since the 5 from 2013 - Contrast the mere 5 days to 31 (2011) and 21 (2019) along with the average back to 2000 of 14 days - Coolest hottest trough June 11th since the 92 of 2013 - Contrast the hottest of just 92 with 102 (2019), 101 (2002), and 100 (2000) along with the average back to 2000 of 96 - I was wondering if incoming El Niño climo might favor less hot but stats since 2000 show El Niño same as non-El Nino

My educated guess for tomorrow's NOAA weekly release is for either +0.9 or +1.0 in Nino 3.4. Any other guesses?

But keep in mind the MJO history that I posted last week: "Newly developing Nino events in 1986 (June), 1997 (May), 2002 (May and again in June), and 2004 (May) all had moderate or stronger moves through both phases 4 and 5 during May and/or June. Looking later: 1976 (Aug/Sep), 1979 (Sep/Oct), 2002 (Aug), and 2009 (Sep) had similar. That means that 7 of the 13 new El Niño events during the period covered by MJO historical data had a moderate or strong move through both 4 and 5 at some point(s) between May and Oct. So, there'd be nothing unusual if 2023 were to have a moderate or strong move through both 4 and 5 this month. http://www.bom.gov.au/climate/mjo/ " --------- So, even though it now appears per latest model consensus that it won't occur this month, don't be surprised if one phase 4 and 5 moderate or strong crossing still occurs between July and October regardless of how strong El Niño gets.

The last 3 runs have been weaker. Like the 6Z GFS, the 12Z GFS has a strong TS developing in the W Caribbean before going inland into the Yucatan. It is the 3rd one in a row moving W into the Yucatan. This now makes 25 GFS runs in a row with a W Caribbean TC that forms within a day of 6/18. Is this W Car TC for real or not? The longest streak of GFS runs in a row that I can recall that turned out to be fake was 30 something. El Niño seasons with +1.3+ in ASO since the late 1800s have had TCs form in mid to late June in the W Caribbean or Gulf more often than not fwiw. Of course, even if that occurs this season, too, it doesn't have to be from the one the GFS has been developing. It could be from something as late as 12 days later. Excellent Tweet from Dr. Cowan:

What Matt Souza says in this post is what I've been wondering about for this season since far wetter than normal at Miami, for example, doesn't necessarily mean from nearby TC activity per looking back in their records. Sometimes it was, especially in some Augusts and Septembers, but sometimes it wasn't: