bluewave

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!

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.

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

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

Yeah, those were some of the strongest VP anomalies that we have seen in early January in the MJO 2 region. There was a record marine heatwave at the time there. The RMM charts didn’t really do the forcing there justice. Sometimes the RMM captures the signal better and other times the VP anomalies.

While SMQs records only began in 1999, they are already on track for one of their highest number of 75° and higher dew point days with 11 days so far. Probably on track for 20 or more days which would make the top 3. 2018 was the first place record holder Total annual 75° dew point days at SMQ since 1999 #1…..33 days….2018 #2….22 days…..2021 #3….20 days….2013 #4…..15 days....2003 #5…..13 days….2020 #6….12 days…..2023….2017….2010 #7…..11 days…..2024….2006 2018 was a year that numerous college dorms had to do mold remediation and relocation of the students due to the record high dew points. https://www.northjersey.com/story/news/passaic/wayne/2018/10/15/mold-mushrooms-inside-william-paterson-university-dorms/1646278002/

I am sure he must since the models have been recently forecasting more SAL and shear after Beryl.

Big SAL outbreak should keep things quieter next few weeks. https://tropic.ssec.wisc.edu/real-time/sal/g16split/movies/goes16split.html

November seems like one of the only months in recent years when we have been able to get even a small cold departure.

Newark is currently in 5th place for most 90° days by by July 8th at 16 days. The average number of 90° days last decade is 33. So Newark is probably on track for 40+ days this year. The only thing which could get in the way of reaching closer to 50 would be a shift to a much wetter pattern like in 2021. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending most 90° days by July 8th and seasonal total 2010-07-08….21…54 1991-07-08 ….19…41 2021-07-08 ….18…41 1986-07-08 ….18…22 2022-07-08 …17…49 2024-07-08 …16 ? 2012-07-08…..16…33 1994-07-08 ....16…39 1993-07-08 …16….49 1987-07-08 …16 …37

A ridge axis out near the Aleutians is always going to be warmer than average for the Northeast like we have seen in the general 500 mb composite over the last 9 winters. We would need some help from the MJO 8 like we got back in January 2022 to at least get one interesting winter month with a break from the dominant MJO 4-7 forcing.

It’s a general repeat of its 22-23 La Niña forecast. Did very well with the main ridge axis over the Aleutians and the Eastern US. The trough verified deeper in the West and the AO was more negative than forecast with more Greenland blocking. Current forecast November 2023 forecast Winter 22-23 verification

One of the bigger issues in recent years has been the models underestimating the WAR day 6-10. So it’s no surprise the WAR is trending stronger the closer we get. But with these record high dew points there is always going to be convection around. We usually need to get within the range of the CAMs like HREF for more specific forecasts. While these CAMS can signal the potential for heavy rains, the exact location is usually off. That’s why I like to look at the Upton and Mt Holly zones in totality for what our options could be. Then wait until we get closer in to refine. Same goes for winter systems since we still haven’t gotten to the point of perfect IMBY forecasts even into the shorter range.

That Euro run would make it an historic 10th warmer to record warm winters in a row for places like NYC and the Northeast region in general. NYC Feb 24…+4.2 Jan 24..+3.3 Dec 23..+5.5 …………..+4.3 Feb 23…+5.2 Jan 23…+9.8 Dec 22…-0.6 …………..+4.8 Feb 22….+1.4 Jan 22….-3.2 Dec 21….+4.7 ……………..+1.0 Feb 21….-1.7 Jan 21….+1.1 Dec 20…+1.7 …………..+0.4 Feb 20…+4.8 Jan 20….+6.5 Dec 19….+0.8 …………….+4.0 Feb 19….+0.9 Jan 19….-0.1 Dec 18…+2.6 …………….+1.1 Feb 18…+6.7 Jan 18….-0.9 Dec 17…..-2.5 …………….+1.1 Feb 17…..+6.3 Jan 17….+5.4 Dec 16….+0.8 …………….+4.2 Feb 16….+2.4 Jan 16….+1.9 Dec 15….+13.3 …………….+5.9

We knew that the bulk of the moisture with Beryl would go west from a few days ago due to the record breaking WAR to 603 dam. Our next chance of more widespread heavy convection will probably hold off until Thursday into Saturday with the slowly moving front. The Euro was too dry last weekend compared to SPC HREF that did much better with the heavy rains. The GFS has the possibility for 2”+ with that round of convection where the best training sets up. So a continuation of the rain on weekends theme going back to March 1st. Data for July 5, 2024 through July 7, 2024 Click column heading to sort ascending, click again to sort descending. CT DANBURY COOP 3.17 NY SOUTH SALEM 0.8 N CoCoRaHS 3.04 CT MERIDEN 2.8 WSW CoCoRaHS 2.93 CT RIDGEFIELD 2.4 NNE CoCoRaHS 2.81 CT BETHEL 3.5 NNE CoCoRaHS 2.64 CT SOUTHBURY 2.3 W CoCoRaHS 2.64 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 2.63 CT WALLINGFORD CENTER 3.3 NNW CoCoRaHS 2.60 CT MIDDLEFIELD 1.4 W CoCoRaHS 2.58 CT GUILFORD COOP 2.52 NY STONY POINT 0.7 NW CoCoRaHS 2.47 CT PROSPECT 1.9 ENE CoCoRaHS 2.33 CT PROSPECT 0.5 SW CoCoRaHS 2.30

Portions of Central NJ have already entered the top 10 for most 95° days and it’s only July 8th. 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 2020 11 0 - 1895 11 11 7 1983 10 0 - 1911 10 0 - 1894 10 12 8 2012 9 1 - 1966 9 0 - 1963 9 1 - 1929 9 2 9 2024 8 179 - 1957 8 0 - 1936 8 2 - 1933 8 19 - 1930 8 1 - 1910 8 0 - 1896 8 9

Warmest start to the summer in portions of Eastern PA. Time Series Summary for Reading Area, PA (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2024-07-07 76.7 0 2 1925-07-07 75.9 0 3 1966-07-07 75.8 0 4 1943-07-07 75.5 0 5 1949-07-07 75.3 0 - 1934-07-07 75.3 0 6 2010-07-07 75.1 0 7 1952-07-07 74.9 0 8 1923-07-07 74.5 0 9 2005-07-07 74.4 0 10 1957-07-07 74.3 0 11 2021-07-07 74.2 0 - 2013-07-07 74.2 0 12 2008-07-07 74.1 0 13 2020-07-07 74.0 0 - 2011-07-07 74.0 0 - 1953-07-07 74.0 0 14 1921-07-07 73.8 0 - 1919-07-07 73.8 0 15 1901-07-07 73.6 0

The only time NYC can beat Newark these days is on an easterly flow which gives Newark a cooling bay breeze.

JFK needs westerly flow to reach 100°. Most of our heatwaves over the last decade have had too much southerly flow component due to the elongation of the subtropical ridge to the east of New England. It could also be that they moved the location of the ASOS back in the 1990s. Remember that JFK is the 9th largest airport in the U.S. at 8.1 sq miles. The current ASOS is located in a marshy area close to Woodmere in the 5 towns area of Long Island. The section of the airport closer to Ozone Park is at least 3-5° warmer. If the old weather station was located closer to that area it could also show another way JFK is getting more sea breeze influence in its readings.

JFK is approaching its longest under 100° streak due to all the high pressure east of New England with our heat waves resulting in more onshore flow. Number of Consecutive Days Max Temperature < 100 for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Period of record: 1948-07-17 to 2024-07-07 1 4016 1999-07-06 through 2010-07-03 2 4009 1972-07-24 through 1983-07-15 3 4007 2013-07-19 through 2024-07-07 4 3610 1983-08-21 through 1993-07-08 5 2210 1966-07-05 through 1972-07-22 6 2185 1993-07-11 through 1999-07-04 7 963 1960-05-02 through 1962-12-20 8 857 1955-03-18 through 1957-07-21 9 817 1951-11-07 through 1954-01-31 10 736 1948-08-28 through 1950-09-02

That’s par for the course with the MJO since the convection which initiates the Rossby wave train can take up to 5-15days to propagate around the world to our area. But sometimes the conditions are such that other teleconnections are already in place which can coincide with the favorable phase and the effect is quicker. So it’s the combination of factors which determine the timing. https://journals.ametsoc.org/view/journals/clim/25/3/jcli-d-11-00033.1.xml The structure of the AO in the geopotential height and surface air temperature fields significantly varies based on the phase of the MJO; the AO index results in a preference for negative polarity in which the anomalously cold (warm) air is prevalent over the upper Midwest and New England (western United States) during the MJO phases 7–8 [convection over the Western Hemisphere; see L’Heureux and Higgins (2008)]. Lin et al. (2009) indicated that when MJO is detected in phases 6–8 (from the western Pacific to the Western Hemisphere), the NAO index is negative 5–15 days later, which can influence the weather in eastern North America and Europe. https://journals.ametsoc.org/view/journals/mwre/144/4/mwr-d-15-0434.1.xml These results are broadly consistent with Barrett et al. (2015). They found an increase in March snow depth for the 7 days following phases 6–8, which would equate well with the findings of our study, given the approximate time lag of 7 days per one phase of the MJO. Their findings also found no air temperature response, indicating that the increase in snowfall was driven by increased storminess and not by a decrease in melt rates. Our results verify this relationship by showing the concomitant modulation of extratropical cyclone activity. This study examined contemporaneous relationships between MJO phase and New England snowstorms. Thousands of kilometers separate these features, so we do not imply that the MJO’s effect is instantaneous. Rather, the MJO’s typical phase speed dictates that the MJO goes through one WH phase every 5–7 days, so some lag from the previous phase is implicit in our composites.

The snowstorm effect can be lagged following MJO 8-2 passages by sometimes 6-10 days after.

This is the warmest start to summer on record for parts of the region. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. 1 1994-07-07 78.5 0 2 2024-07-07 77.9 0 3 2010-07-07 77.4 0 4 1993-07-07 76.8 0 5 2021-07-07 76.4 0 Time Series Summary for Reading Area, PA (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2024-07-07 76.7 0 2 1925-07-07 75.9 0 3 1966-07-07 75.8 0 4 1943-07-07 75.5 0 5 1949-07-07 75.3 0 - 1934-07-07 75.3 0 Time Series Summary for New Brunswick Area, NJ (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2024-07-07 74.8 0 - 1899-07-07 74.8 0 2 2010-07-07 74.6 0 - 1901-07-07 74.6 0 3 1898-07-07 74.5 0 4 1925-07-07 74.4 0 5 1934-07-07 74.1 0 Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT Click column heading to sort ascending, click again to sort descending. 1 2024-07-07 73.1 0 2 1994-07-07 73.0 0 3 2010-07-07 72.9 0 4 2008-07-07 72.6 0 5 1999-07-07 72.1 0 Time Series Summary for SOMERSET AIRPORT, NJ Click column heading to sort ascending, click again to sort descending. 1 2024-07-07 73.4 0 2 1999-07-07 72.6 7 3 2010-07-07 72.5 0 - 2005-07-07 72.5 0 4 2021-07-07 72.0 0 - 2013-07-07 72.0 0 - 2008-07-07 72.0 0 5 2020-07-07 71.9 0

BTV has us beat so far in that department. Data for June 1, 2024 through July 8, 2024 Click column heading to sort ascending, click again to sort descending. NJ NEWARK LIBERTY INTL AP WBAN 79 NY NY CITY CENTRAL PARK WBAN 79 NJ HARRISON COOP 78 NJ TETERBORO AIRPORT WBAN 78 NJ CALDWELL ESSEX COUNTY AP WBAN 78 NJ TETERBORO AIRPORT COOP 76 CT NEW HAVEN TWEED AP WBAN 76 NY LAGUARDIA AIRPORT WBAN 75 Data for June 1, 2024 through July 8, 2024 Click column heading to sort ascending, click again to sort descending. VT BURLINGTON INTERNATIONAL AIRPORT WBAN 80 NY CANTON 4 SE WBAN 75 NY MALONE COOP 75 VT VERGENNES COOP 75 VT ISLAND POND AP COOP 75