bluewave

I have been getting the heavy downpours here just east of HVN but the severe has been to my north this month.

What was interesting about the 09-10 and 10-11 winters is that the record Atlantic blocking developed during June and July of 2009 and carried over into early 2011. The record NE Pacific blocking also developed in June and July of 2013 and carried into early 2015. Someone should do an in depth study as to why the winter patterns emerged during the summer first. Plus to set records for NE Pacific and Atlantic blocking from 2009 to 2015 so close together was very impressive. All-time snowfall records were set in this period from DC to Philly and Boston. NYC and Long Island couldn’t rival 95-96 since the snowfall ended too soon near the end of January in 2011.

Very obvious error since there is no way Phoenixville would ever have that many more 95° days than Baltimore. The most 95° days Baltimore had during that period was 19 in 1931. Time Series Summary for Baltimore Area, MD (ThreadEx) - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 1931 19 0 2 1941 18 0 3 1944 17 0 4 1930 16 0 5 1943 14 0 - 1934 14 0

3rd highest June dew point on record here at KHVN. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=155&network=CT_ASOS&zstation=HVN&var=max_dwpf&w=all&threshold=100&hour=12&sdate=0101&edate=1231&month=jun&_r=t&dpi=100&_fmt=png

Plenty of fuel for the severe storms today as JFK just tied its all-time highest June dew point of 75°. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=155&network=NY_ASOS&zstation=JFK&var=max_dwpf&w=all&threshold=100&hour=12&sdate=0101&edate=1231&month=jun&_r=t&dpi=100&_fmt=png

Some of the recent studies found that it was a coincidence and others not. Just a coincidence https://news.climate.columbia.edu/2019/01/22/debunking-solar-cycle-north-atlantic-winter-weather-connection/ Some signal possible in February https://acp.copernicus.org/articles/22/7893/2022/

Most unstable sounding of 2024 so far with over 4000 CAPE forecast around lunchtime. Also the highest dew points around 78°. So storms should quickly become severe with torrential downpours which such high moisture content.

They didn’t find much relation to the low sunspots in the paper. suggesting that the unusually low solar activity contributed little, if any, to the observed NAO anomaly during the 2009/10 winter. 17] The origin and predictability of the extremely negative phase of the NAO during the winter of 2009/10 have been explored by means of numerical experimentation. Different possible forcing mechanisms have been tested such as El Niño, the QBO, and reduced solar insolation. However, none of the forcings considered in this study was able to reproduce the negative phase of the NAO, especially in terms of its magnitude. The results of this study, therefore, support the hypothesis that both the development and persistence of negative NAO phase resulted from internal atmospheric dynamical processes. This may explain why most operational seasonal forecasting systems had problems in predicting the negative NAO winter when started in late autumn (e.g., forecasts issued in October and November 2009). The results of this study suggest that internal atmospheric dynamics are an important source of low-frequency atmospheric interannual variability [see also James and James, 1989] including extreme atmospheric circulation anomalies. Furthermore, this study suggests that internal atmospheric dynamics are able to produce extremely persistent atmospheric circulation anomalies which are associated with substantial extended-range predictive skill. From a dynamical point of view it will be interesting to better understand the processes responsible for the persistence of the negative NAO throughout most of the 2009/10 winter.

My is guess is that 10-11 was more about the 150 year -NAO event lingering from the previous year than it was about the La Niña. That historic blocking pattern began during the 09 summer with one of the coolest June-July periods on record around NYC. It carried through the 09-10 winter and reversed in early February 11. So it’s unlikely that we ever see the 09-10 all-time snowfalls in the Mid-Atlantic surpassed during an El Niño or any other ENSO state. Same goes for over 60” of snow in only 33 days around NYC in 10-11 during a La Niña or any other ENSO state. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011GL046786 The winter of 2009/2010 was one of the most negative winters of the North Atlantic Oscillation (NAO) during the last 150 years. While most operational extended-range forecasting systems had difficulties in predicting the onset of the negative NAO phase, once established, extended-range forecasts were relatively skilful in predicting its persistence. Here, the origin and predictability of the unusual winter of 2009/10 are explored through numerical experimentation with the ECMWF Monthly forecasting system. More specifically, the role of anomalies in sea surface temperature (SST) and sea ice, the tropical atmospheric circulation, the stratospheric polar vortex, solar insolation and near surface temperature (proxy for snow cover) are examined. None of these anomalies is capable of producing the observed NAO anomaly, especially in terms of its magnitude. The results of this study support the hypothesis that internal atmospheric dynamical processes were responsible for the onset and persistence of the negative NAO phase during the 2009/10 winter.

At least some measurable rainfall which was the case going back to March 1st.

We are back to the rain on weekends theme since March 1st after a brief break.

The only preseason metric which has worked for all La Ninas since 2010 has been the October early MJO indicator. This has helped out with the snowfall potential. But every La Niña since 11-12 has been warmer than average here in the Northeast.

We are probably better off using the SSTs west of the Dateline in the tropics and subtropics rather than what is happening in the official Nino regions. It seems to me the WPAC warm pool has been driving the bus since 15-16. The RONI has been trying to do this but it still feels incomplete to me. Since the MJO in the 4-7 regions has become so dominant regardless of El Niño, La Niña, or neutral.

After the really comfortable dew points on Friday ,we are headed for our first mid 70s dew points of the season on Sunday. This will push the HX into the upper 90s in NJ. Some spots may approach a 100 HX.

It looks like the -PDO has been driving the strong La Niña background state with the 100° June heat we have just seen in the East. As the actual La Niña has been slower out of the gate than usual. May be related to the ongoing record marine heatwaves slowing the drop in SSTs east of the Dateline. But as long as the -PDO is so negative, we are getting a very strong La Niña background state regardless of what happens east of the Dateline. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Jun Click column heading to sort ascending, click again to sort descending. 1 2021 103 La Niña 2 2011 102 La Niña - 1994 102 El Niño - 1993 102 Neutral - 1952 102 Neutral - 1943 102 7 1988 101 El Niño to La Niña - 1966 101 El Niño to La Niña 9 2024 100 El Nino to La Niña - 1959 100 El Niño to neutral - 1953 100 El Niño - 1934 100

The best the PDO has been able to do has been a rise back to around -1.5 before dropping again to the -2 to -3 range.

It felt great today. Quick turnaround for weekend with parts of area challenging the all-time PWAT record for June near 2.5”.

The record breaking 500 mb heights and surface high pressures just keep coming out there.

You can see how the tree growth is getting even thicker over the NYC ASOS as it couldn’t even make it to 95° during the big heatwave. Monthly Data for June 2024 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. NJ NEWARK LIBERTY INTL AP WBAN 100 NJ HARRISON COOP 100 NJ TETERBORO AIRPORT COOP 97 NY LAGUARDIA AIRPORT WBAN 97 NJ TETERBORO AIRPORT WBAN 97 NJ CALDWELL ESSEX COUNTY AP WBAN 97 NY WEST POINT COOP 96 NY PORT JERVIS COOP 96 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 96 CT NORWICH PUBLIC UTILITY PLANT COOP 95 NJ CHARLOTTEBURG RESERVOIR COOP 94 NY NY CITY CENTRAL PARK WBAN 94 Corona, Queens…………………………………………………..98 Astoria, Queens…………………………………………………..97 Fresh Kills, Staten Island……………………………………..99 Hillsborough-Duke Somerset………………………………100 NYC was much closer to Newark during past 100° Junes at Newark before the tree issues began to really be a factor after the 1990s ASOS change. Monthly Data for June 1988 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. NJ NEWARK LIBERTY INTL AP WBAN 101 NY MINEOLA COOP 101 NJ PLAINFIELD COOP 100 NY LAGUARDIA AIRPORT WBAN 99 NJ CRANFORD COOP 98 NJ CANOE BROOK COOP 98 NY NEW YORK AVE V BROOKLYN COOP 98 NY NY CITY CENTRAL PARK WBAN 98 Monthly Data for June 1966 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. NJ NEWARK LIBERTY INTL AP WBAN 101 NY NY CITY CENTRAL PARK WBAN 101 NJ PATERSON COOP 101 NJ LITTLE FALLS COOP 100 NJ PLAINFIELD COOP 99 NJ ELIZABETH COOP 98 NJ JERSEY CITY COOP 98 NJ CANOE BROOK COOP 98 NY SCARSDALE COOP 98 NY WEST POINT COOP 98 Monthly Data for June 1952 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. NJ ELIZABETH COOP 103 NJ PATERSON COOP 103 NJ NEWARK LIBERTY INTL AP WBAN 102 NJ CANOE BROOK COOP 102 NY NEW YORK LAUREL HILL COOP 102 NY WEST POINT COOP 102 CT STAMFORD COOP 102 NJ PLAINFIELD COOP 101 NY LAGUARDIA AIRPORT WBAN 101 NJ RIDGEFIELD COOP 101 NJ LITTLE FALLS COOP 101 NY SUFFERN 2 E COOP 101 NY MINEOLA COOP 101 CT WATERBURY ANACONDA COOP 101 NJ JERSEY CITY COOP 100 NY NEW YORK BENSONHURST COOP 100 NY NY CITY CENTRAL PARK WBAN 100 Monthly Data for June 1943 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. CT DANBURY COOP 105 NJ NEWARK LIBERTY INTL AP WBAN 102 NJ CANOE BROOK COOP 102 NY PORT JERVIS COOP 100 NJ ELIZABETH COOP 100 NJ RIDGEFIELD COOP 100 NY BEDFORD HILLS COOP 100 CT BALTIC COOP 100 NJ PLAINFIELD COOP 99 NY LAGUARDIA AIRPORT WBAN 99 NY NY CITY CENTRAL PARK WBAN 99 Monthly Data for June 1934 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. NY MOUNT VERNON COOP 101 NJ PLAINFIELD COOP 101 NY NY CITY CENTRAL PARK WBAN 101 CT WATERBURY ANACONDA COOP 101 CT WATERBURY CITY HALL COOP 101 NJ JERSEY CITY COOP 100 NJ NEWARK LIBERTY INTL AP WBAN 100 NY FLUSHING COOP 100 NJ LITTLE FALLS COOP 100

Aerosols have been masking global warming over the years. But they have no idea how much since each model gives them a different answer. In addition to shipping places like China have cleaned up the sulphur emissions also. I think the scientific community is pretty much scrambling to figure out why the temperature increase was so much beyond expectations in recent years. Clouds and aerosols are very uncertain since the models have such a wide range of results.

It’s possible that the rapid reduction of shipping aerosols due to the new regulations that went into effect in 2020 is boosting the marine heatwaves in the mid-latitudes. One of these record marine heatwaves is driving the record SSTs east of Japan leading to the record -PDO values. The ongoing record marine heatwave in the Atlantic are driving the record +AMO. We will probably need further studies to confirm the exact reason for this sudden global temperature rise above model forecasts in recent years. But one of the uncertainties in climate modeling is how changes in clouds and aerosols affect global climate sensitivity to CO2 forcing.

While you are technically correct, the 18-19 El Niño wasn’t able to couple for much of the winter. So we effectively didn’t have an El Niño between 15-16 and 23-24. The La Niña background state is getting so strong, that we need a borderline super to actual super El Niño in order to couple with the 500 mb pattern. Plus the record MJO 4-6 in December 2015 and throughout the 23-24 event were more typical for La Ninas before this 10 year period. So even 2 such strong events couldn’t mute the WPAC warm pool influence. https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall

June is our most recent to 10 warmest month around the region. This will be the 53rd top 10 warmest for spots since 2010. The only top 10 coldest month was February 2015.

My guess is that the major global temperature spike since the 14-15 super El Niño shifted the Pacific to this new state we have been seeing with record MJO 4-6 action in the Tropical West Pacific and record SSTs from Japan to north of Hawaii in the subtropics. This pattern has been driving the record winter warmth. It’s interesting how this period was preceded by the 13-14 and 14-15 winters which only lasted a few years before this much longer 9 year pattern so far. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GL101078 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.

More of a gradient pattern over the next week. The major 95°+ heat shifts to the south with a possible brief return around Sunday. Then we wait and see what the pattern does as we head into July. It generally looks like heat will build to our SW and come NE from time to time before we get breaks from storms and fronts dropping south from Canada. So it looks like the rainfall pattern will continue to favor the more northern areas as the drought continues to expand over the Southeast and Mid-Atlantic. Newark and NJ had record warmth over the last week with 5 days going over 95°. Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. 2024-06-20 97 71 2024-06-21 100 77 2024-06-22 95 77 2024-06-23 99 75 2024-06-24 84 73 2024-06-25 94 66 2024-06-26 98 72 No surprise that this was the warmest June 20th to 27th on record for Newark and it beat the 2010 Nino to La Niña transition. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. 1 2024-06-27 84.1 1 2 1943-06-27 82.5 0 3 2010-06-27 81.9 0 4 1949-06-27 81.3 0 5 1997-06-27 79.9 0 Source region for the heat to our SW continues to dry out.