GaWx

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:

Make that 24 W Caribbean TCs in a row with today's 6Z GFS, which gets it to TS strength before weakening over the Yucatan. The 0Z GFS had a TC but only a strong TD before weakening over Belize. Getting to 24 isn't near the record for what turned out to be a fake, which I recall getting to somewhere into the 30s. So, we need another two days to approach that record.

Over the last 5 days, the GEFS/EPS have retained going into a moderate MJO phase 4 but have backed off then going into moderate phase 5. Instead they and all models go faster back into the COD before reaching 5. Based on recent years, that's somewhat unusual per my memory and keeping in mind that the very warm MC tends to favor the MJO getting well into phase 5.

OISSTv2.1 cooled 0.078, largest 24 hour cooling since before 3/15. While these are notable, I'm confident like you are that these are just short term "corrections" after a very rapid warming.

Correction time in 3.4 (I assume only for short term): 24 hour cooloffs -CDAS has cooled 0.061, largest cooling since Mar 19th -Coral Reef has cooled 0.081, largest cooling since before Mar 15th

Over the last 4 years, the very warm WPac/Maritime Continent has helped lead to stronger and longer MC MJO phases, often mild for the E US in winter. In addition, it often causes pseudo-MC phases when the MJO isn't in the MC. All of this tends to favor a stronger than average SE ridge.

Related to this, the RONI maxed out at only ~0.4, not even at weak El Niño levels.

I'm admittedly a bit more wary about the chance that this is real based on the higher level of June activity on average preceding +1.3+ ASO El Nino's and considering that ASO in 2023 is headed there. I'll re-list them in this way to better make that point: No mid to late June W Car/GOM TC/STC formation: ASO ONI 0.5, 0.5, 0.5, 0.5, 0.6, 0.6, 0.6, 0.6, 0.6, 0.7, 0.7, 0.7, 0.8, 0.8, 0.8, 0.8, 0.8, 0.8, 0.9, 1.0, 1.0, 1.1, 1.2, 1.2, 1.4, 1.6, 2.1, 2.2 Mid to late June W Car/GOM TC/STC formations: ASO ONI 0.5, 0.6, 0.6, 0.7, 0.7, 0.8, 1.3, 1.3, 1.6, 1.6, 1.6, 1.6, 1.9, 2.2 So, for ASO of 0.5 through 1.2, there were only 6 of these W basin mid to late June formations from 30 years (20% ratio). But things really start picking up in June when the subsequent ASO is 1.3+ with 8 formations from just 11 years (73% ratio).

The last couple of Euro ens runs have gone back to very quiet through day 15 after a few runs with only a subtle increase in activity. Today's 12Z GFS run makes 17 in a row, which is still nowhere near the record for a fake.

For the first time in many days, the CDAS Nino 3.4 SSTa actually ticked down from six hours earlier albeit barely (from +0.976 to +0.975). It also looks like Nino 4 is cooling some.

I'm redoing my W Caribbean/GOM TC formations 6/11-30 for El Niño years based on ASO Nino 3.4 SSTa having to be +0.5+ as per @ncforecaster89recommendation: 1852: 0.5 none 1855: 0.5 none 1864: 0.6 none 1877: 2.2 none 1884: 0.6 none 1885: 0.8 none 1888: 1.3 one 1896: 1.2 none 1899: 0.8 one 1900: 0.5 none 1902: 1.6 two 1904: 0.6 one 1905: 1.4 none 1914: 0.8 none 1918: 0.8 none 1923: 0.7 one 1925: 0.7 none 1930: 1.1 none 1940: 0.8 none 1941: 0.9 none 1951: 1.0 none 1953: 0.8 none 1957: 1.3 one 1963: 1.2 none 1965: 1.9 one 1969: 0.8 none 1972: 1.6 one 1976: 0.6 none 1977: 0.6 none 1982: 1.6 one (STS) 1986: 0.7 one 1987: 1.6 none 1991: 0.6 none 1994: 0.6 one 1997: 2.1 none 2002: 1.0 none 2004: 0.7 none 2006: 0.5 one 2009: 0.7 none 2015: 2.2 one 2018: 0.5 none Doing it this way gives only 14 formations for 41 El Niño years for a 34% ratio. That leaves 40 formations for the 131 non-El Nino years for a 31% ratio. So, 34% for El Niño vs 31% for others is essentially a wash. But this still shows that El Niño years aren't less prone than non-El Nino years to formations during mid to late June as is the case later in the season. ------------- Edit: Further breakdown: -Only 6 formations out of 27 years (22% ratio) with ASO of +0.5 to +1.0 -2 formations out of 6 years (33% ratio) with ASO of +1.1 to +1.5. But small sample size. -Interestingly, 6 formations out of 8 years (75% ratio) with ASO of +1.6+! This is consistent with ncforecaster89's stats showing more June US landfalls with stronger El Niño events. But sample size is pretty small.

Yeah, I was counting as "El Niño years" those years for which there was El Niño by that autumn without necessarily requiring El Niño by ASO. Is your way better? Perhaps. So, I'll redo my analysis requiring El Niño in ASO if I get time.

Regarding recorded 6/11-30 W Car/Gulf TC/STC geneses since 1851, 43% (23) of the 54 storms formed during the 53 El Nino years. That's notable considering that only 31% of the 172 seasons (53 of them) since 1851 were associated with El Niño. Here are the 23 mid to late June recorded TC/STC geneses during El Nino years in either the W Caribbean or Gulf: 1865, 1880, 1887, 1888*, 1899, 1902 (2), 1904, 1913, 1923, 1929, 1939, 1957, 1958, 1965*, 1968 (2), 1972*, 1982*, 1986, 1994, 2006, 2015* * notes super El Niño years. A whopping 5 of the 7 (71%) super El Niño years had one of these storms! I'm mentioning this because there's a chance that 2023 will reach super status. This leaves 31 storms that formed during the same period in the same region during 119 non-El Nino seasons or only 26% of them. In summary, there were 23 mid to late June W Car/Gulf storms during 53 El Nino seasons for a ratio of 43%. This compares to 31 from 119 non-El Nino seasons or a ratio of only 26%. That tells me that whereas we still should take the 12 GFS runs in a row with a W Car/Gulf TCG in week 2 with a grain based on its bias toward that, we should also keep in mind that this year being El Niño means it has a significantly higher chance of occurring vs if it weren't El Niño.