bluewave

If one of these random runs west of the ensemble means near Cape Cod actually happen, then it will be a big win for the newer AI models. This will be the big test case coming up. Imagine if they end up being right. Maybe we could actually nail a day 7-10 snowstorm forecast for once.

1.37 here at KHVN in only 30 minutes with plenty of low lying street and parking lot flooding.

Torrential downpour here at KHVN.

The weaker ridge to our east probably prevented Newark from getting a SW flow and 99-100° instead of the more onshore flow and underperforming highs there.

0.6 in 30 min at the Brooklyn mesonet.

The last time the RONI was at similar summer levels for a developing El Niño was back in 2004. This summer also had the westward forcing lean. Also note the very active hurricane season back in 2004. 2004-2005 was memorable for the El Niño not getting much stronger than it was in August and September.

Yeah, contrast the NYC number of 90 days in 2006 to 1977. No trees blocking the sensors in 1977 allowed NYC and EWR to get close. NYC was so far back in 2006 that it was ridiculous. Data for January 1, 2006 through December 31, 2006 Click column heading to sort ascending, click again to sort descending. State Name Station Type Number of Days Max Temperature >= 90 NJ PLAINFIELD COOP 30 NJ HARRISON COOP 30 NJ TETERBORO AIRPORT COOP 30 NJ TETERBORO AIRPORT WBAN 29 NJ NEWARK LIBERTY INTL AP WBAN 27 NJ CRANFORD COOP 24 NJ MIDLAND PARK COOP 24 NJ CANOE BROOK COOP 22 NY LAGUARDIA AIRPORT WBAN 22 NY BRONX COOP 21 CT DANBURY COOP 20 NY DOBBS FERRY-ARDSLEY COOP 18 NY WEST POINT COOP 18 NJ CALDWELL ESSEX COUNTY AP WBAN 16 NY MINEOLA COOP 16 NY NEW YORK AVE V BROOKLYN COOP 15 NY PORT JERVIS COOP 13 NY WANTAGH CEDAR CREEK COOP 13 CT NORWICH PUBLIC UTILITY PLANT COOP 12 NY JFK INTERNATIONAL AIRPORT WBAN 12 NJ ESSEX FELLS SERVICE BLDG COOP 11 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 11 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 11 NY ISLIP-LI MACARTHUR AP WBAN 10 NY MONTGOMERY ORANGE COUNTY AP WBAN 10 NY RIVERHEAD RESEARCH FARM COOP 9 NY MIDDLETOWN 2 NW COOP 9 NY FARMINGDALE REPUBLIC AP WBAN 9 NY NY CITY CENTRAL PARK WBAN 8 Data for January 1, 1977 through December 31, 1977 Click column heading to sort ascending, click again to sort descending. State Name Station Type Number of Days Max Temperature >= 90 CT NEW HAVEN COOP 34 NY NEW YORK LAUREL HILL COOP 30 NY WEST POINT COOP 28 NJ PLAINFIELD COOP 27 NJ NEWARK LIBERTY INTL AP WBAN 26 NJ CRANFORD COOP 25 NY DOBBS FERRY-ARDSLEY COOP 25 NY NY WESTERLEIGH STAT IS COOP 23 NY NY CITY CENTRAL PARK WBAN 23 NJ TETERBORO AIRPORT WBAN 23 NJ CANOE BROOK COOP 22 NJ LITTLE FALLS COOP 21 CT STAMFORD 5 N COOP 21 NY NEW YORK AVE V BROOKLYN COOP 19 NY MARYKNOLL COOP 19 NY SCARSDALE COOP 19 NY PATCHOGUE 2 N COOP 17 NY SUFFERN COOP 17 NY WALDEN 1 ESE COOP 17 NJ WANAQUE RAYMOND DAM COOP 16 NJ RINGWOOD COOP 16 NY LAGUARDIA AIRPORT WBAN 14

The old Central Park station when it wasn’t under a tree through the 1980s was usually warmer than LGA and sometimes EWR. Makes sense since Central Park is further from the water than LGA and EWR. The July of 1977 heatwave wouldn’t be as big a story had the Central Park equipment been under a tree like it is today. No chance these days anymore of multiple 100s and highs warmer than Newark or LGA. Repeat that July 1977 heatwave today and there would probably be no 100s at Central Park. Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 1977-07-13 93 73 1977-07-14 92 73 1977-07-15 96 72 1977-07-16 98 75 1977-07-17 97 78 1977-07-18 100 78 1977-07-19 102 78 1977-07-20 92 75 1977-07-21 104 78 Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 1977-07-13 92 73 1977-07-14 91 73 1977-07-15 93 71 1977-07-16 97 72 1977-07-17 99 77 1977-07-18 98 75 1977-07-19 100 78 1977-07-20 90 75 1977-07-21 102 78 Data for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 1977-07-13 92 72 1977-07-14 89 72 1977-07-15 90 69 1977-07-16 96 72 1977-07-17 95 74 1977-07-18 95 76 1977-07-19 99 75 1977-07-20 90 74 1977-07-21 99 78

The airports were actually cooler this week due to the influence of the sea breezes. The ASOS units at the airports are located on grassy strips. Many of ours are close to water like EWR,LGA, and JFK. But some would say how about the tarmac and all that concrete? Well the sensors are probably placed similarly to a backyard Wunderground station in any of those airport neighborhoods. Heck, there may even be more grass than around the average residents houses in those neighborhoods. The neighborhoods contain miles and miles of paved driveways, sidewalks, and streets. So the airport represents the same land use as the local residential neighborhoods with probably more grass.

That’s really the point when we now see from the NYC micronet how upper 90s was the norm for maxes during this heatwave in the densely packed neighborhoods around Brooklyn and Queens. So letting the Central Park ASOS OBS drift so far from reality with the tree growth doesn’t really make any sense. These urban inner city neighborhoods were hotter than Newark this week. The UHI in Queens is much stronger than Newark with 2 days not dropping below 80°. Cornoa, Queens at ground level. 9/8…92/75 9/7….98/81 9/6….96/80 9/5….94/78 9/4…..90/77 9/3…..93/69

I get it that there are many who would like to go back to our cooler climate of days past. I am not a big fan of so much warmth either. But we can clearly see that Newark and urban NE NJ is right in line with the regionally top 5 warmest start to September.

The record -PDO from the fall into winter 21-22 was no match for the WPAC warm pool forcing west of the Dateline which resulted in a strong January +PNA and record snows on Long Island. So more and more the WPAC is having a much greater influence on our climate than the ENSO regions further east. Forcing just west to the Dateline is a fantastic winter pattern for us. But a little further west near Indonesia gives us record warmth. Unfortunately, the MJO 4-6 forcing near Indonesia is occupying more time during our winters since 15-16 than the 7-8 region west of Dateline which was dominant in 14-15.

Not that I am suggesting a repeat of December 2015, but the long range guidance was pretty bad even into late November on the position of the Aleutian low for December. So not surprised that an important detail like a strong MJO 4-6 even during that super El Niño wasn’t well forecast very far in advance. But at least the more traditional blocky version of the El Niño emerged in January and February to save the winter. Late November forecasts typical El Niño +PNA for December MJO 4-6 gave us the worst La Niña-like December pattern in history despite a super El Nino

An 80° first week of September is pretty impressive. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Sep 1 to Sep 7 Missing Count 1 1973-09-07 83.1 0 2 1961-09-07 82.4 0 3 1953-09-07 81.4 0 4 2018-09-07 81.1 0 5 2023-09-07 80.2 0

The only decent winter since 18-19 was 20-21. We got a break in the persistent Niña background state to allow a strong enough +PNA -AO. Luckily, when the PNA flipped negative, the trough stayed stuck in place near the East from the earlier pattern. So if this El Niño continues to have trouble coupling, then we’ll need some decent +PNA -AO intervals to have a better winter outcome. Still very early so it’s possible. We’ll see what other hints we get as the fall progresses. The bar for a good winter is set pretty low this year after last winter.

Anything under +1 could iffy. But it’s still too early to know what the peak figures will be.

Just not sure if a MEI or RONI that low in this new era would even allow the El Niño to couple? That was the same range we were in back in 18-19 and look what happened. So we would need to rely getting strong enough -AO or -NAO to try and mute the persistent Niña background state. But we really need to see where these ENSO readings go and if we can couple the next few months to know what we may be dealing with pattern wise during the winter.

This is the 2nd highest September dew point reading on record at 78° here at KHVN. You can really feel it when you go outside. 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=sep&_r=t&dpi=100&_fmt=png

A large portion of the Atlantic Basin had their warmest ERSST August SSTs on record helping to boost the global SST record even higher.

I get the same charts referenced in the most recent CPC update.

No doubt. But based on the other other 5 most positive Dec-Mar +NAO seasons, the collective snowfall average in Boston was only around 16”. Includes 2020,2012, 2000, 1995, and 1989. So it just goes to show the power of that historic -EPO+PNA block. Things were just a little too progressive with the record +NAO for places around NYC to challenge their max around 75”. But 50” was a nice consolation prize even though the big one went a little too far to the east to cash in on the jackpot.

Newark would have made an easy 99° without the sea breeze especially when Queens made it 98° away from the water.

We are seeing the results of those record SSTs.

The Euro did a nice job with the 98-100° peak heat in NJ. This is one of those rare times it was correct about the highest temperatures staying west of Newark. So the sensors close to the bay make it susceptible to sea breezes when interior sections can get warmer. Queens away from the sea breeze also made it to 98°. But the ASOS at LGA is right on the water so they were 2° cooler than Corona to the south which made it to 98°. https://www.njweather.org/data/daily/455 ▼ Fort Dix NJ 2023-09-07 USFS 100 71 Monthly Data for September 2023 for New Jersey Click column heading to sort ascending, click again to sort descending. Name Station Type Highest Max Temperature TETERBORO AIRPORT WBAN 99 SOUTH JERSEY REGIONAL AIRPORT WBAN 98 Atlantic City Area ThreadEx 97 Newark Area ThreadEx 97 NEWARK LIBERTY INTL AP WBAN 97 ESTELL MANOR COOP 97 ATLANTIC CITY INTL AP WBAN 97 http://www.nysmesonet.org/networks/nyc Corona 98 Monthly Data for September 2023 for New York Click column heading to sort ascending, click again to sort descending. Name Station Type Highest Max Temperature LAGUARDIA AIRPORT WBAN 96

It made up for the NYC area model error in January 2015 when the low went too far to the east. The later portion of January has become a good period for KU events since January 2011. So that has been a reliable period to forecast a big snowfall event.The funny thing about the 14-15 seasonal forecasts was some of the calls had a record -NAO based on fall Siberian snow cover. But we got a record +NAO. The plot twist was that the Boston area set their new snowfall record. Again, another striking event which would have gotten laughed at if presented on a fall snowfall forecast with record +NAO and record snowfall in the same sentence. That’s what I mean about the uniqueness of all the winter patterns since 09-10. Roughly 2 week snowfall periods since 2010 and the number of 12"+ snowstorms in NYC Metro forecast zones. Oct 29-Nov 15.....3 Nov 16-Nov 30....0 Dec 1- Dec 15.....0 Dec 16-Dec 31....3 Jan1-Jan 15.......4 Jan16-Jan 31.....6 Feb 1-Feb 15.....7 Feb 16-Feb 28...1 Mar 1- Mar 15....6 Mar 16-Mar 31...1 Apr 1-Apr 16.....0