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bluewave

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  1. Yeah, it’s one of the reasons that the 2012 extent minimum record has endured for so long. These strong reverse dipole summer patterns have become more frequent during the post 2007-2012 record dipole era. The other has been the much thinner pack making new records more difficult to achieve. Plus the lack of major May preconditioning like we saw in 2012 and 2020. Judah Cohen recently commented on this more favorable pattern for sea ice retention. https://www.aer.com/science-research/climate-weather/arctic-oscillation/ I do want to once again conclude with the PCHs this summer. I really don’t know what to make of the PCH plot as shown in Figure 11 once again this week, which looks very strange to me. To highlight how bizarre it has been I include in Figure iii the same plot from one year ago. This plot of episodic warming or what I like to desribe as “pulsing red”of tropospheric PCHs with cold stratospehric PCHs that occasionally descend to the surface makes much more physical sense to me. Larger amounts of greeenhouse gases in the polar stratosphere should result in cooling of the polar stratosphere punctuated by warming when upwelling wave energy is absorbed and thus warms the polar stratosphere but limited to the winter months but in particular January and February. The warm PCHs in the stratosphere I assume have the potential to descend to the surface and increase high latitude blocking resutling in cooler temperatures in the Eastern US and Northern Europe, yet for the most part this has not happened and it is looking less likely to ocuur for a significant aount of time this summer. This pattern or low pressure over the Central Arctic surrounded by high pressure across the mid-latitudes, which results in a quasi zonal flow is favorable for preserving Arctic sea ice. We can see in Figure iv that sea ice extent is comparable to the best two summers and I would expect the trends to continue. Arctic sea ice is tracking below normal and should continue right through the September minimum. However, the possibility of a new record low sea ice minimum is looking less and less likely.
  2. The Euro has a pretty slow frontal passage with the record WAR so convection lingers into the afternoon.
  3. Yeah, we are lucky this isn’t as great of a seasonal 500mb height departure as 02-20-18 was. But these extreme 500 mb height anomalies have been becoming more frequent since around 2010. Members of the forum much more liked the numerous 500mb winter height records near Greenland in the 2009 to 2011 era. Also the winter 500 mb height records over the EPO and PNA NE Pacific regions during 2014 and 2015. The record 500mb ridge in the PAC NW and British Columbia areas during the summer of 2021 was associated with the all-time heat in those areas. But for monthly departures the December 2015 standing wave with gave us the 50° December +13.3° departures around NYC could actually be the most extreme right up there with March 2012 in the Great Lakes region. So this process can be expressed in new all-time daily 500 mb and temperature records or monthly averages. Plus we can’t forget the record 500 mb ridge parked over Canada for much of 2023.
  4. Yeah, this is the SPC HREF max potential through 12z Saturday since it only runs out 48 hrs. But if the WAR verifies stronger, then the front could slow down and linger past 12z especially the further to the east you get. The 0z and 12z runs tomorrow should be more definitive on the timing as it get with in the more reliable range.
  5. Especially the areas that get the best training.
  6. These weak lows which develop in the tropics can really deliver some very heavy rains as they come north.
  7. The highest heat index relative to past Julys is located in NJ so far this summer. FWN is off to their highest heat index July on record while ISP isn’t as impressive. Better dew point pooling west of NYC and stronger sea breezes on Long Island. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=76&network=CT_ASOS&station=BDR&season=jul&varname=feel&agg=max&year=1893&w=bar&hours=0-23&_r=t&dpi=100&_fmt=png
  8. Parts of Central NJ are approaching their all-time record highest number of 95° days in a year. Hightstown already has 11 days and it’s only July 10th. The all-time record in a year was set in 2002 at 17 days. They will be getting close to that seasonal record next week following the next round of 95°+ major heat. Hillsborough-Duke is close with 10 days reaching 95° so far. Newark has only 5 days due to the frequent cooling bay breezes there this summer with so much onshore flow. Harrison a few miles further away from Newark Bay has 7. Time Series Summary for HIGHTSTOWN 2 W, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 2002 17 0 2 1955 16 8 3 1953 14 0 4 2021 13 0 - 2018 13 1 - 2016 13 2 - 2010 13 4 - 1988 13 0 - 1949 13 0 5 2022 12 2 - 1999 12 0 - 1944 12 1 6 2024 11 176 - 2020 11 0 - 1895 11 11 7 1983 10 0 - 1911 10 0 - 1894 10 12
  9. Over 75 climate sites have had their warmest start to summer.
  10. Yeah, first 603-604 dam WAR on record next few days.
  11. Our heatwave will be delayed several days due to this record ridge being further east than average. But we will probably see 95-100° heat by early next week in NJ. Remember the last ridge amplification in late June also had the main heat delayed by several days.
  12. It’s almost as impressive as it was last July. https://www.cbc.ca/news/canada/nova-scotia/unprecedented-marine-heat-wave-canadian-atlantic-ocean-1.6986139
  13. I think the upper ocean heat content is so high that hurricanes and typhoons won’t really shift the surface SSTs as much as they did in the past with lower upper ocean heat content. Remember several years ago how we had one of the most active typhoon seasons on record followed by one of the strongest marine heatwaves during the following winter. The reserve of deep warmth in the WPAC was so strong in the fall of 2019 into 2020 that the record IOD cooling near Indonesia was reversed to record warmth in under 2 months.
  14. Interesting cloud street pattern over LI and CT with the strong winds and high dew points.
  15. The 95-96 record winter snowfall in NYC may have been related to the AMO warming which occurred that year. Boston had their snowiest winter in 15 with the brief shift to the +PDO. But the shift only lasted a few years before we entered the record -PDO regime of recent years. The famous 76-77 winter occurred as the PDO was changing from negative to positive. So we seem to get interesting winters around these change points.
  16. It’s pretty rare to get gusts over 40 mph with dew points over 75° outside a tropical storm or hurricane. Kennedy Intl PTSUNNY 83 75 77 S28G43
  17. It might actually be right this time since it’s the first time that the GFS was warmer with a long range heat wave forecast than the Euro.
  18. I know. It was never this humid for all my trips to Action Park back in the 80s.
  19. FWN is currently in 1st place for highest average daily average maximum dew point in July at 71.1°. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=76&network=NJ_ASOS&station=FWN&season=jul&varname=dwpf&agg=max&year=1893&w=bar&hours=0-23&_r=t&dpi=100&_fmt=png
  20. The 20-21 mismatch was as if the RONI was so strong in the fall that the MJO 5 peaked in October and it was weak enough in December for other factors to mute the La Niña background state. We saw this during the stronger La Ninas in 10-11 and 17-18. The weaker La Nina’s like 11-12, 16-17, and 22-23 had weaker MJO 5 activity in October which got stronger during the winter. So an inverse MJO relationship during La Ninas between the fall and winter. RONI….OND 2020 -1.52
  21. We would need a mismatch similar to DJF 20-21 and Jan 22 to see some improvement over the last 2 winters. https://www.climate.gov/news-features/blogs/enso/did-northern-hemisphere-get-memo-years-la-niña https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JD035546 Was the mismatch that we saw in December-January really that unusual? We know from previous blog posts (like this one) that the atmosphere varies quite a bit from one La Niña to the next, and the atmosphere never fully resembles the average of all events. To address this question, I evaluated the similarity between the individual December-January 500 hPa maps and the average La Niña pattern (for the 13 moderate-to-strong La Niña episodes). For this calculation, I use the pattern correlation, a metric that summarizes the similarity in a single number: a value of 1 means perfect match, 0 means complete mismatch, and -1 means mirror opposites (3). Pattern correlations between the individual La Niña and average La Niña December – January 500 hPa geopotential height anomalies north of 15°N for the 13 strongest La Niña episodes since 1950. Positive values indicate at least some degree of pattern matching, with 1 indicating a perfect match, and negative values indicate a mismatch between the two patterns. NOAA Climate.gov figure with NCEP/NCAR Reanalysis data obtained from the NOAA Physical Sciences Laboratory. The pattern correlations are usually substantially positive for moderate-to-strong La Niñas, which indicates that most events share some basic similarity with the average La Niña pattern. This confirms that La Niña is a reliable source of predictability outside of the tropics (and a big reason that we have an ENSO Blog!). However, the pattern correlation for the December 2020 – January of 2021 is the lowest of the 13 events and is actually slightly negative. That means you can argue that the Northern Hemisphere atmosphere looked a little more like El Niño than La Niña!
  22. The global guidance agrees that somebody in the OKX and PHI forecast zones will jackpot higher than 2.50” into Saturday. It will be interesting to see what type of totals the CAMS like the SPC HREF start printing out in a few days. All the ingredients are there for torrential downpours where the best training sets up.
  23. First time Reading ever had 10 days reaching 95° or higher by July 9th. Time Series Summary for Reading Area, PA (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2024-07-09 10 0 2 2012-07-09 8 1 - 1925-07-09 8 0 3 1901-07-09 7 0 4 1966-07-09 6 0 - 1911-07-09 6 0 5 2021-07-09 5 0 - 2010-07-09 5 0 - 1999-07-09 5 0 - 1988-07-09 5 0 - 1984-07-09 5 0 - 1921-07-09 5 0 - 1919-07-09 5 0 - 1898-07-09 5 1
  24. While SMQ is only 9 days into the month as of the update yesterday, the average afternoon heat index is 95.4°. This would be the highest on record for July should it continue for the rest of the month. This is due to the record high dew points so far this month. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=76&network=NJ_ASOS&station=SMQ&season=jul&varname=feel&agg=max&year=1893&w=bar&hours=0-23&_r=t&dpi=100&_fmt=png
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