bluewave

Some radar estimates over 5.00” around that area.

Looks pretty rough on the Henry Hudson.

Yeah, reports of flooded roadways around the area coming in.

Probably plenty of flooding in spots around Yonkers and the Bronx with radar estimates in excess of 3.00”.

The heaviest may have fallen right over the GSB.

3.00” radar estimates in the Gilgo and Oak Beach area.

Some roads in NJ already blocked due to flooding.

Very heavy downpours now on the Garden State Parkway.

Area fell into 3rd place behind 2012 and 2020. Loss rates have slowed just enough last week. Plus the next 7 days was when 2012 ran away with the lead. Record preconditioning that year with very strong May melt ponding and follow up strong summer dipole pattern. The great Arctic cyclone came during the next 7 days that year.

Impressive rates at ISP with 1.03” in only the last 15 minutes. https://www.weather.gov/wrh/timeseries?site=kisp

Picked up a quick .41 here in 20 min with the heavy downpour.

This current August forecast for the DJF looks like a blend of the most recent La Niña forecasts from Aug 20,21, and 22.

Harrison, NJ is currently in the lead across the area with 35 days reaching 90° so far this year. That is currently the 9th highest seeasonal total on record. Newark is further back at only 30 days since the ASOS is very close to the bay and even a slight SSE flow affects temperatures there. So Newark is currently in 15th place. They will probably finish the season somewhere in the top 10. LGA is further back in 18th place with only 19 days. JFK only has 5 days which is in 17th place. Time Series Summary for HARRISON, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 2010 50 30 2 2018 47 0 - 2002 47 8 4 2022 44 0 5 2005 41 9 6 2016 40 0 7 2020 39 0 - 2019 39 0 8 2021 38 0 9 2024 35 148 - 2012 35 21 10 2023 33 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 2010 54 0 2 2022 49 0 - 1993 49 0 4 1988 43 0 5 2021 41 0 - 2002 41 0 - 1991 41 0 6 2016 40 0 - 1983 40 0 - 1959 40 0 7 1994 39 0 - 1944 39 0 8 2005 37 0 - 1987 37 0 9 2018 36 0 - 1949 36 0 10 2015 35 0 11 1961 34 0 12 2012 33 0 - 1999 33 0 - 1995 33 0 - 1966 33 0 13 1955 32 0 - 1953 32 0 - 1943 32 0 14 2020 31 0 - 2011 31 0 - 1973 31 0 - 1952 31 0 15 2024 30 148 Time Series Summary for LAGUARDIA AIRPORT, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 2010 48 0 2 2018 38 0 3 2002 35 0 4 2020 34 0 - 1991 34 0 5 2016 32 0 6 1983 31 0 7 2022 30 0 - 2005 30 0 - 1953 30 0 8 1955 29 0 - 1944 29 0 9 2012 28 0 - 1949 28 0 10 1959 27 0 11 2019 26 0 - 1999 26 0 - 1993 26 0 - 1988 26 0 12 2021 25 0 - 1966 25 0 13 1952 24 0 14 2007 23 0 - 1995 23 0 - 1941 23 0 15 2006 22 0 - 1994 22 0 - 1980 22 0 - 1970 22 0 16 2013 21 0 17 2015 20 0 18 2024 19 148 - 2011 19 0 - 2008 19 0 - 1987 19 0 - 1957 19 0 - 1943 19 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 2010 32 0 2 1983 26 0 3 2002 21 0 4 1971 18 0 - 1949 18 0 5 2005 17 0 - 1991 17 0 6 2022 16 0 - 2012 16 0 - 1959 16 3 - 1955 16 2 7 2016 15 0 - 1995 15 0 - 1961 15 0 8 1999 14 0 - 1988 14 0 - 1966 14 0 - 1952 14 0 9 2011 13 0 - 1993 13 0 - 1984 13 0 - 1977 13 0 - 1970 13 0 - 1969 13 0 - 1963 13 0 10 2020 12 0 - 2015 12 0 - 2006 12 0 - 2003 12 0 - 1978 12 0 - 1968 12 0 - 1953 12 0 11 1987 11 0 - 1981 11 0 - 1980 11 0 - 1962 11 1 12 2021 10 0 - 1997 10 0 - 1974 10 0 13 2017 9 0 - 2013 9 0 - 2008 9 0 - 1989 9 0 - 1956 9 0 14 2023 8 0 - 2018 8 0 - 2001 8 0 - 1986 8 0 - 1975 8 0 - 1973 8 0 - 1972 8 0 - 1964 8 1 15 2019 7 0 - 2007 7 0 - 1994 7 0 - 1957 7 1 - 1948 7 198 16 2009 6 0 - 2000 6 0 - 1992 6 0 - 1990 6 0 - 1965 6 0 17 2024 5 148 - 1998 5 0 - 1985 5 0 - 1976 5 0 - 1954 5 1

Euro seasonal first guess for DJF is similar to the recent winter decadal pattern. Strong Aleutian ridge and Southeast ridge couplet. So places like NYC are probably looking at the record 10th consecutive warmer winter since 15-16.

This was actually the 2nd highest monthly +PNA on record leading to the record heat over Western North America. Very impressive that 5 of the strongest monthly +PNA readings were July La Ninas. Top 10 monthly +PNA readings with La Niña Julys bolded +2.66….. MAY…1993 +2.60…..JUL….2024 +2.54…..JUL….2022 +2.47..…JAN…..1981 +2.38…MAR……1983 +2.24…JUL…….1998 +2.22…AUG……1977 +2.21….JUL……2007 +2.16…..JUL…..1988 +2.16…..JAN….2016

Strong HREF signal for locally 5”+ from the PRE next 48 hrs where the best training eventually sets up.

July 2024 has just set the new July all-time monthly +PNA record at +2.60. Very strong +PNA patterns began to become a feature with La Ninas in July starting in 1988. So nearly all the top 10 strongest +PNA patterns in July have been during La Ninas. It only took 2 years to beat the previous record set in. 2022. So we can use it as a marker of how strong the La Niña 500 mb pattern has already become after the very strong El Niño last winter. https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt La Nina July +PNA and JJA…..RONI 2024….+2.60…?…………….1st place July +PNA 2022…..+2.54….-0.82…….2nd place July +PNA 2020…..+1.73…..-0.73 2017……+1.86…..-0.16 2007……+2.21….-0.54 1998……+2.24…..-1.07 1988……+2.16…..-1.49

This has been the 7th wettest summer through August 4th at Tweed New Haven just to my SW. Nearly 10.00” here since June 1st. This is even before we start seeing the heavy rainfall from Debby. Time Series Summary for NEW HAVEN TWEED AP, CT Click column heading to sort ascending, click again to sort descending. 1 2009-08-04 16.29 0 2 1972-08-04 15.58 0 3 2006-08-04 10.95 0 4 2013-08-04 10.88 0 5 2023-08-04 10.03 2 6 2008-08-04 10.02 0 7 2024-08-04 9.95 0 8 2003-08-04 9.79 0 9 1953-08-04 9.23 0 10 1971-08-04 9.13 0

Got really dark here and the streetlights had to come on at 5:30. Quick 1.46” and much wetter than yesterday but less wind. Another very dramatic sky before the storm. https://www.weather.gov/wrh/timeseries?site=khvn

The only way we can get cooler temperatures these days during the summer is through plenty of rain.

Parts of the region have the chance to surpass 100” of precipitation since last July especially if we can generate follow up tropical systems after Debby into September or October. Data for July 1, 2023 through August 4, 2024 NJ Click column heading to sort ascending, click again to sort descending. HIGHLAND LAKES 1SW COOP 82.37 MINE HILL TWP 0.4 NE CoCoRaHS 82.21 Data for July 1, 2023 through August 4, 2024 NY Click column heading to sort ascending, click again to sort descending. WEST POINT COOP 86.56 STONY POINT 0.7 NW CoCoRaHS 85.69 CARMEL 4N COOP 85.45 HIGHMARKET 2W COOP 84.97 SOUTH SALEM 0.8 N CoCoRaHS 84.37 THORNWOOD 0.7 NW CoCoRaHS 82.17 PEEKSKILL 0.4 N CoCoRaHS 81.65 PHONECIA 2SW COOP 80.78 SHRUB OAK COOP 80.59 Data for July 1, 2023 through August 4, 2024 CT Click column heading to sort ascending, click again to sort descending. COLUMBIA 2.6 S CoCoRaHS 94.27 BURLINGTON COOP 93.69 NEWINGTON 1.9 SSW CoCoRaHS 93.52 BRISTOL 2.8 NNE CoCoRaHS 92.77 BRISTOL 2.7 WNW CoCoRaHS 92.35 SOUTH WINDHAM 1.3 NNE CoCoRaHS 91.53 MOOSUP 1.7 NE CoCoRaHS 90.94 SALMON BROOK 4.9 WSW CoCoRaHS 90.55 MIDDLEFIELD 1.4 W CoCoRaHS 90.30 PROSPECT 1.9 ENE CoCoRaHS 90.22 Data for July 1, 2023 through August 4, 2024 VT Click column heading to sort ascending, click again to sort descending. AVERILL COOP 81.76 NASHVILLE 1 E COOP 80.53 STAMFORD 5.0 NNE CoCoRaHS 80.51 CABOT 3.9 ENE CoCoRaHS 80.00 RI Data for July 1, 2023 through August 4, 2024 Click column heading to sort ascending, click again to sort descending. COVENTRY 1.2 SW CoCoRaHS 89.65 NORTH CENTRAL STATE AIRPORT WBAN 89.27 CRANSTON 1.2 SSE CoCoRaHS 86.98 WEST WARWICK 3.3 SSW CoCoRaHS 86.83 GREENE 1.4 E CoCoRaHS 86.77 FOSTER 4.0 SSE CoCoRaHS 86.51

If we only get the PRE like the GFS and suppressed track then my guess is a 5”+ jackpot somewhere in the region. But if Debbie gives us a PRE and then tracks north like the Euro than a 10”+ jackpot for somebody. We probably won’t know for several more days yet. But it looks very wet either way.

It looks like the pattern is becoming wet enough that the 100° heat and warmest part of the summer is behind us now.

This chart goes back much further and shows how the recent warming of the WPAC is unprecedented. Remarkable Changes in the Dominant Modes of North Pacific Sea Surface Temperature https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GL101078 The second PC is mostly positive from 1990 to 2021 and strongly positive from 2014 to 2021 (Figure 6b), reflecting the positive SSTa across much of the North Pacific that EOF 1 alone does not capture. The weak negative lobe in the second EOF lessens the warming near the coast of North America. As EOF 2 describes less of the variance than EOF 1, it might be expected that its shape is more variable when calculated over different time periods, interestingly, the positive lobe in EOF 2 has grown steadily when calculated over successively longer time periods (Figure 6b, x-ticks). The positive lobe of EOF 2 filled up 98% of the North Pacific when calculated over the period 1950–2018 and similarly for HadISST data at 93% (Figure S1.6 in Supporting Information S1). While EOF 2 has not been invoked as often as the PDO as a measure of SST variability, the robust evolution since 2014 is still worthy of note. Figure 6 Open in figure viewerPowerPoint (a) The second EOF of SST over the PDO region for the entire time series (1950–2021). (b) The principal component for the second EOF is shown on the left y-axis using colored bars. The right y-axis (x symbols) shows the percentage of data points greater than zero in the second EOF from 1970 to 2021. 5 Conclusions The fundamental result of this study is that the first EOF of SST in the North Pacific has changed starting in 2014. For more than 20 years, the PDO has been used to describe the state of the North Pacific. However, since the marine heatwave of 2014, there have been remarkable changes to the dominant mode of SST in the North Pacific. The spatial pattern of the first EOF of SST from 1950 to 2021 is notably different from the PDO, suggesting that though the PDO served as a useful metric of SST variations until 2014 (Johnstone & Mantua, 2014), it may no longer be as effective a climate index for the North Pacific. From 1950 until the 2014 MHW, the first EOF remained consistent in its proportion of positive and negative regions with both taking up roughly half the area of the North Pacific (and with the positive region taken to be the eastern Pacific). When EOFs are calculated from 1950 to endpoints after 2014, the first EOF has a maximum positive region covering 77% of the North Pacific, with a PC indicating the largest anomalies on record. These changes to the first EOF/PC of North Pacific SST are nothing short of remarkable. In concert with these changes, the second EOF/PC of SST has also undergone profound evolution since 2014. This second EOF now accounts for approximately 18% of the variability, growing from 13% during the 1950–2013 period. The spatial structure of the second EOF now is positive over almost the entire basin, with a PC that has grown strongly positive in the last several years. Thus, the second EOF/PC describes warming over much of the Pacific not in the positive lobe of the first EOF. A relevant aspect of our analysis is that we did not remove a trend from the data before calculating the EOFs and PCs. This is consistent with the original calculations of EOFs in the North Pacific (Davis, 1976) and more recent analysis by Johnstone and Mantua (2014), but inconsistent with the definition of the PDO which did have a global mean trend removed (Mantua et al., 1997; Zhang et al., 1997). Whether or not a trend was removed had little effect on the first EOF, and thus the PDO, until 2014. Two of our results lead to this conclusion: first, our first PC calculated between 1950 and 1993 agreed with the PDO with a correlation coefficient of 0.97; and second, our first EOF calculated with successively longer time series did not change in shape until 2014. There are many approaches to removing a trend from time series (Deser & Phillips, 2021; Frankignoul et al., 2017; Solomon & Newman, 2012). We investigated two of these approaches: first we removed a least-squares fit of a line to the global average temperature as in the original definition of the PDO (Figure S2 in Supporting Information S1), and second, we removed a least-squares fit of a line from each grid point in the North Pacific (Figure S3 in Supporing Information S1). In each case the EOF analysis reproduced the PDO spatial pattern and index, suggesting that the PDO remains a good measure for the variability relative to the trend. In general, removal of a trend (as by least-squares fitting of a line, e.g.,) tends to deemphasize the ends of a record. In our analysis, the inclusion of the trend highlights the fact that the warming in the eastern Pacific has increased notably in recent years, a fact that would be obscured if a linear trend had been removed. The PDO is recognized to be a result of many processes that may cause temperature variability (Newman et al., 2016) rather than any singular phenomenon. The many processes that affect SST have apparently combined to create both this era of frequent marine heatwaves beginning in 2014 and a fundamental change to the first mode of SST. The persistence of the marine heatwaves was studied by Di Lorenzo and Mantua (2016) who also invoked a number of interacting processes, suggesting that the variance described by the PDO would increase in a warmer climate. Di Lorenzo and Mantua (2016) explicitly removed a trend before calculating the EOFs of SST, so that their EOFs described variance relative to the trend. The PDO is based on a constant spatial pattern defined by the EOF that described the most variance of SST through the mid 1990's. However, there is no guarantee that the EOFs of SST will remain constant as climate change continues. This concern about indices based on EOFs applies also to the North Pacific Gyre Oscillation (Di Lorenzo et al., 2008), which describes variance in sea surface height. The PDO is widely used as a measure of temperature in the eastern boundary upwelling system along the west coast of North America (e.g., Weber et al., 2021). The period of persistent marine heatwaves since 2014 has made the PDO less useful as an index of temperature in this region because it does not reflect the recent increase. In general, using PCs from a basin-wide analysis as indices of temperature for specific regions may be problematic because the influences from distant parts of the basin affect the PCs. Options moving forward may include: (a) updating the definition of the first mode of temperature variability, as we have done here, (b) explicitly accounting for the trend in addition to the PDO for a measure of temperature, or (c) defining a new temperature metric in a specified area in the region as is done for the various measures of El Niño (Trenberth, 1997) or more recently as in the NEP index (Johnstone & Mantua, 2014). Interestingly, the NEP was first published just before the recent period of MHWs, and the value of the approach championed in Johnstone and Mantua (2014) has only increased. The wide-ranging effects of the recent period of MHWs are likely to be seen in continuing studies of the eastern North Pacific. thunderbolt 1