bluewave

Yeah, the second half of 2023 was so much more extreme than anything we have seen before.

It figures the MJO would wait until March to finally go into phase 8 like last year. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Lowest Min Temperature Mar 19 to Mar 31 Missing Count 2024-03-31 29 8 2023-03-31 29 0

Record air and sea surface temperatures continue.

Yeah, a top 3 finish with JFK recording it’s wettest March. Maximum 1-Day Total Precipitation for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date Period of record: 1869-01-01 to 2024-03-23 1 4.25 1876-03-25 2 3.86 2010-03-13 3 3.66 2024-03-23 4 3.44 1977-03-22 5 3.10 1983-03-18 6 2.98 2005-03-28 7 2.95 1914-03-01 8 2.94 1901-03-11 9 2.63 1979-03-06 10 2.61 1953-03-13 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Mar Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 2024 8.79 8 2 2010 8.62 0 3 1980 8.17 0 4 1953 7.93 0 5 2001 7.00 0 6 1993 6.83 0 7 1983 6.66 0 8 1984 5.99 0 9 2017 5.79 0

This band coming through has some of my heaviest rainfall rates of the year so far just east of KHVN.

Pretty ridiculous SST warmth in the Atlantic for so early in the year combined with a developing La Niña.

The radar presentation reminds me of when a tropical system makes landfall to our south and runs up just inland from the coast.

Wettest March day on record for Philly.

Yeah, nice event for the ski resorts.

40 and rain here.

Looks like a top 10 wettest March day potential. Maximum 1-Day Total Precipitation for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date Period of record: 1869-01-01 to 2024-03-22 1 4.25 1876-03-25 2 3.86 2010-03-13 3 3.44 1977-03-22 4 3.10 1983-03-18 5 2.98 2005-03-28 6 2.95 1914-03-01 7 2.94 1901-03-11 8 2.63 1979-03-06 9 2.61 1953-03-13 10 2.45 2010-03-30 Maximum 1-Day Total Precipitation for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date Period of record: 1931-02-01 to 2024-03-22 1 3.99 2010-03-13 2 2.71 1993-03-13 3 2.60 1977-03-22 4 2.57 1991-03-03 5 2.53 1953-03-13 6 2.50 1934-03-31 7 2.44 1983-03-18 8 2.39 1997-03-31 9 2.35 1962-03-12 10 2.34 1951-03-30

The worst hard freeze that I ever had in my garden back on the LI South Shore was in November 2017. We had just come off the warmest October on record with numerous days in the 70s and 80s. The 70s persisted into the first week of November. This allowed my garden to have one of my latest fall blooms. All the impatiens were really blooming strong like it was still mid-summer into November. My Encore Azaleas had a unusually good fall bloom also. So when we had 3 consecutive near record lows in the mid 20s around November 10th all the Impatiens and the Azalea blooms quickly shriveled up. The Azalea never came back the next spring so I had to replace it with some beautiful fountain grass which was much lower maintenance. That fall was a preview of the following winter into spring with the period of Arctic cold after Christmas coexisting with the historic February 80° warmth. So a continuation of the short Arctic outbreak pattern surrounded by much more impressive and longer lasting warmth.

The really damaging freeze around the region was last May when some spots in Upstate NY got down into the low 20s. https://www.wamc.org/2023-09-19/a-late-may-frost-caused-some-ny-farms-to-lose-most-of-their-apples The evening of May 17 Critz turned on a large frost fan which helps mix warmer air from above with cooler air at ground level to try and prevent frost forming on the flowering trees. Then the temperature dipped down to 23 degrees. "32 is okay," Critz said. "30, 29, you start having a little damage maybe 10 percent. You can go down to like 27 you'd be like 50% damage, but usually there's enough blossoms even if you lose 50% of them, you're still going to bear a good crop. Then it went down to 23 and just killed everything." The apples he does have, have a frost ring around them. These apples will be pressed to make sweet cider and hard cider.

Looks like NYC only got down to 29°so it avoided the hard freeze some of the colder guidance was calling for. The GFS actually did better again that some of the other guidance which had mid 20s. So hopefully there won’t be much damage to the early blooms.

A real soaker on the HREF with a 2.5” to locally 5.0” range where the best banding and training sets up.

October 2005 was the beginning of the shift to people having basement flooding when they never did before. Especially when I was living back in Long Beach. Numerous months since then with near or over 10” of rain at spots in the area.

This could push parts of the area close to 10.00” on the month. Data for March 1, 2024 through March 21, 2024 Click column heading to sort ascending, click again to sort descending. State Name Station Type Total Precipitation NY SMITHTOWN 2.0 SSW CoCoRaHS 7.64 CT SALEM 3.6 SE CoCoRaHS 7.50 NY DEER PARK 1.0 NE CoCoRaHS 7.18 CT OAKDALE 2.6 WNW CoCoRaHS 6.97 CT EAST LYME 0.5 SW CoCoRaHS 6.97 CT NORWICH 5.2 SE CoCoRaHS 6.97 CT MYSTIC 3.4 NW CoCoRaHS 6.96 CT NORWICH 2.5 NNE CoCoRaHS 6.89 CT STRATFORD 0.2 ESE CoCoRaHS 6.81 NY ST. JAMES COOP 6.80 NY HOWARD BEACH 0.4 NNW CoCoRaHS 6.68 CT PROSPECT 1.9 ENE CoCoRaHS 6.63 CT FAIRFIELD 1.5 NE CoCoRaHS 6.56 CT STRATFORD 0.9 W CoCoRaHS 6.53 CT GUILFORD COOP 6.44 CT GUILFORD CENTER 2.7 WSW CoCoRaHS 6.44 CT ESSEX VILLAGE 0.9 S CoCoRaHS 6.44 NY CENTEREACH 1.3 NE CoCoRaHS 6.37 NY MOUNT SINAI COOP 6.36 CT NORWICH PUBLIC UTILITY PLANT COOP 6.35 NY SELDEN 1.6 ESE CoCoRaHS 6.32 NJ MONTCLAIR 0.7 N CoCoRaHS 6.26 NY WANTAGH 0.3 ESE CoCoRaHS 6.23

Today will be only the 10th day in NYC since 12-1 with a -5 or lower departure. But the +5 or greater days since then have been at 53. All the extended warmth makes these colder days seem colder than they really are since we get used to the warmer temoeratures.

Figures that the strongest MJO 8 since December would wait until the start of astronomical spring. So we may have to be really patient for our next 70° day. It could take until April if the models are correct about the next 10 days.

Maybe such an extreme SST rise leading into the El Niño altered the usual timing of the global temperature response surrounding this event.

NYC is on track to make it to the top 10 wettest Marches. Some really hot summers followed years with this much March precipitation. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Mar Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 2010 10.69 0 2 1983 10.54 0 3 1980 10.41 0 4 1876 8.79 0 5 1953 8.76 0 6 1912 7.70 0 7 2001 7.48 0 8 1977 7.41 0 9 1993 6.64 0 10 1913 6.47 0 11 1994 6.33 0 12 1984 6.30 0 13 2011 6.19 0 14 1933 6.08 0 15 1944 5.98 0 16 1967 5.97 0 17 1919 5.96 0 18 1942 5.91 0 19 1932 5.82 0 20 1881 5.81 0 21 1899 5.77 0 22 1974 5.76 0 23 1951 5.62 0 24 1877 5.56 0 25 1871 5.54 0 26 1922 5.52 0 27 1890 5.50 0 28 1901 5.47 0 29 1936 5.45 0 30 2007 5.35 0 31 1896 5.28 0 32 2017 5.25 0 33 1872 5.24 0 34 1997 5.18 0 35 2018 5.17 0 36 1991 5.16 0 37 1998 5.08 0 38 1956 5.03 0 39 1906 5.01 0 40 2005 4.96 0 41 1989 4.93 0 - 1987 4.93 0 43 1902 4.84 0 44 1931 4.83 0 45 1968 4.79 0 46 1939 4.78 0 47 1920 4.75 0 48 1914 4.74 0 49 1940 4.73 0 50 2015 4.72 0 51 1880 4.66 0 52 1888 4.62 0 - 1884 4.62 0 54 1869 4.61 0 55 2024 4.57 12

The timing of the jump in temperatures this year was related to the onset of the El Niño. But the magnitude of warmth was a function of the record heat being released from the oceans. Much more heat available this El Niño than previous ones. So even a significantly weaker El Niño than 2015-16 had more warming potential. But it will still take more research specifically as to why this lead to a sharper temperature increase earlier in the year than past El Niño events.

My guess is that this warming spike is related to the rapid subtropical SST warming which has occurred since the last super El Niño in 15-16. https://www.nature.com/articles/s43247-023-00839-w In this study, we evaluate the ocean warming pattern derived from four decades of satellite measurements. We find widespread strong subtropical ocean warming, concentrating mostly on the western ocean basins. In contrast to these observations, studies of paleoclimate suggest that the greatest ocean warming occurs at higher latitudes. By pairing the observed warming pattern with SST evolution in long-term climate simulations, we propose that the observed warming pattern is constrained by ocean dynamics of surface convergence (downwelling, subtropical gyres) and divergence (upwelling, subpolar gyres) rather than being dominated by internal variabilities, such as the PDO. This pattern emerges only at the early stage (a few decades) of anthropogenic warming when absorption of heat concentrates in the upper ocean. On centennial (for the Northern Pacific Ocean) to millennial (for the North Atlantic Ocean and Southern Hemisphere) timescales, when deep ocean water warms, the greatest ocean warming is expected to occur in the subpolar region, as indicated by paleo-reconstructions and the long-term and equilibrium climate simulations.