bluewave

I meant to say east of the Dateline. While that 500mb anomaly center south of the Aleutians has been steadily increasing, it has grown to unprecedented levels of strength and persistence since the 15-16 super El Niño. I zoomed into the 500mb anomaly center where you placed the arrow. I define the La Niña background state as record SSTs west of the Dateline along the equator in the MJO 4-6 regions and east of Japan to south of the Aleutians. So both the tropics to the mid-latitudes. We even had a ridge there last winter during the borderline super El Niño and during the uncoupled El Niños in 18-19 and 19-20. Anytime we have a strong enough ridge axis out south of the Aleutians it pumps up the Southeast ridge and or ridge over the Northeast. This is the main reason we have seen the first 9 year run of record to warmer than normal winters in a row for the Northeast.

But it’s not the subsurface east of the Dateline driving the pattern. This pattern also has a warmer surface component west of the Dateline. That warm pool at the surface over the WPAC is what has been producing the perma-La Niña background state since the 15-16 super El Niño.

Not much difference between +0.24 and +0.55 ONI as either in our older climate would have been more El Niño modoki-like.

One of the biggest examples of this was the warm neutral ONI to weak modoki El Niño in 19-20. It behaved more like a robust La Niña due to the record WPAC warm pool and marine heatwave east of Japan really amping up the Aleutian ridge and Southeast ridge. So the La Niña background state prevailed even with the SSTs approaching weak modoki status.

The exact track of the remnants will be important as to where the heaviest axis of rainfall sets up. But this pattern is much more amplified than normal. The 12z GFS is advertising the first 603 dam WAR pattern this week.

2nd day in a row with 80° dew points in NJ. https://www.njweather.org/maps/

The current Nino 3.4 is +0.4. But due to the record WPAC warmth driving the record -PDO we have been getting a very robust La Niña atmospheric response. The 100° heat in June and record breaking Beryl deepening so early is like an even more amped up La Niña response than usual with the record Atlantic SST boost. So my guess is that the happenings over the Western Pacific will continue to be more influential than what the official ONI readings are.

Dew points have been steadily rising as a warmer atmosphere holds more moisture. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=76&network=NY_ASOS&station=JFK&season=summer&varname=dwpf&agg=mean&year=1893&w=bar&hours=0-23&_r=t&dpi=100&_fmt=png

77° dew point here now after .82 of rain. My sunglasses actually fogged up going outside now that the sun is out. The area has a shot at one of the highest July average dew points for the whole month. https://www.weather.gov/wrh/timeseries?site=khvn https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=76&network=NJ_ASOS&station=SMQ&season=jul&varname=dwpf&agg=mean&year=1893&w=bar&hours=0-23&_r=t&dpi=100&_fmt=png

My guess is that 108° is probably the actual PA state high temperature record set in 2011, 1936, and 1918. Monthly Data for July 2011 for Pennsylvania Click column heading to sort ascending, click again to sort descending. NORRISTOWN COOP 108 READING REGIONAL AIRPORT WBAN 106 LEWISTOWN COOP 106 STEVENSON DAM COOP 106 Reading Area ThreadEx 106 SAFE HARBOR DAM COOP 105 NORTHEAST PHILADELPHIA AIRPORT WBAN 105 SHIPPENSBURG COOP 105 MILLHEIM COOP 105 NEW CASTLE 1 N COOP 105 LOCK HAVEN SEWAGE PLANT COOP 105 RENOVO COOP 105 HERITAGE FIELD AIRPORT WBAN 105 DOYLESTOWN AIRPORT WBAN 105 Monthly Data for July 1936 for Pennsylvania Click column heading to sort ascending, click again to sort descending. MARCUS HOOK COOP 108 FARRELL SHARON COOP 108 CHAMBERSBURG 1 ESE COOP 107 LAWRENCEVILLE 2 S COOP 107 PHILADELPHIA NAVY YARD COOP 107 SPRING GROVE COOP 106 EPHRATA COOP 106 GEORGE SCHOOL COOP 106 WILLIAMSPORT (RIVER) COOP 106 FRANKLIN COOP 106 Williamsport Area ThreadEx 106 VANDERGRIFT COOP 106 HANOVER COOP 105 YORK 3 SSW PUMP STN COOP 105 WEST CHESTER 2 NW COOP 105 NESHAMINY FALLS COOP 105 LEBANON 4 WNW COOP 105 LOCK HAVEN COOP 105 ARDMORE COOP 105 SUMMERDALE NEAR COOP 105 Monthly Data for August 1918 for Pennsylvania Click column heading to sort ascending, click again to sort descending. CLAYSVILLE 3 W COOP 108 COATESVILLE 1 SW COOP 107 LANCASTER 2 NE PUMP STN COOP 107 SADSBURYVILLE COOP 107 PHILADELPHIA WBAN 106 PALMERTON COOP 106 LEBANON 4 WNW COOP 106 Philadelphia Area ThreadEx 106 BEAVER DAM COOP 106 CLEARFIELD CLIMAT COOP 106 HANOVER COOP 105 GETTYSBURG COOP 105 YORK 3 SSW PUMP STN COOP 105 QUAKERTOWN COOP 105 BETHLEHEM LEHIGH UNIV COOP 105 INDIANA WBAN 105 GEORGE SCHOOL COOP 105 READING 4 SW WBAN 105 LEWISBURG COOP 105 VANDERGRIFT COOP 105 Reading Area ThreadEx 105

You can see what an outlier that one completely dry weekend was back in mid-June. Newark Jul 6-7……….0.08…so far with much heavier totals in other spots Jun 29-30….0.39 Jun 22-23…..0.04 Jun 15-16……0.0 Jun 8-9……….T Jun 1-2……….T May 25-25…..T May 18-19…..0.04 May 11-12…0.38 May 4-5…..0.31 Apr 27-28…0.11 Apr 20-21…0.05 Apr 13-14…0.04 Apr 6-7…….T Mar 30-31…0.01 Mar 23-24….3.10 Mar 16-17…..T Mar 9-10….1.46 Mar 2-3…..1.31

The SPC HREF had the right idea but its heavy rain axis was a little too far NW. I did much better here. But the exact placement is always a toss up.

Same here. Picked up .50 in 15 minutes. The atmosphere was saturated with 75° dew points and 2.00” PWATS. It’s one of the few times I had fog and light drizzle transition to such a heavy downpour in July.

I was talking about the lower soil moisture south of I-78 in mid-June and how it would likely be a temporary situation before the heavier rains eventually arrived. This has been the pattern in recent years. Brief drier patterns of lower soil moisture before more impressive heavier rains than the brief drier patterns which preceded them. I also posted how the area has only seen D0 to D2 drought conditions since the last real drought here in 01-02 reaching a D3 requiring actual water restrictions in NYC. So in effect these have been nuisance dry patterns resulting in brown lawns. But here in CT we never really got into the brown lawn situation since it was cooler and wetter than in NJ. Whenever the dew points go 75° to 80° and PWATS reach 2.00”+ we always get very heavy to locally torrential downpours.

It’s been the wettest July to June period up here with 80.00”+ in spots. Data for July 1, 2023 through July 6, 2024 Click column heading to sort ascending, click again to sort descending. CT PROSPECT 1.9 ENE CoCoRaHS 84.92 CT NORWICH 2.5 NNE CoCoRaHS 83.36 CT OAKDALE 2.6 WNW CoCoRaHS 82.91 CT MIDDLEFIELD 1.4 W CoCoRaHS 82.61 CT MIDDLEFIELD 0.6 SE CoCoRaHS 81.36 NY WEST POINT COOP 81.33 CT BROOKFIELD 3.3 SSE CoCoRaHS 81.25 CT NORTHFORD 0.8 SW CoCoRaHS 81.21 CT COLCHESTER 0.6 ENE CoCoRaHS 81.07 NY STONY POINT 0.7 NW CoCoRaHS 81.05 CT GRISWOLD 0.9 N CoCoRaHS 80.81 CT HIGGANUM 0.8 NE CoCoRaHS 80.58 CT HIGGANUM 0.7 N CoCoRaHS 80.39 CT WATERBURY 1.3 WNW CoCoRaHS 80.14

The forecast from the ECMWF for La Nada during NDJ is identical to this point in 2016 after that super El Niño. Remember the ECMWF runs warm with its forecast plumes. The forecast was for -0.2 in NDJ and -0.7 verified. The actual ONI weakened to La Nada -0.3 in DJF. It matched the other weaker La Niña to La Nada winters which had the very strong La Niña background state. So it will be interesting to see how this one ends up and whether we follow the recent pattern of the La Nada and weak La Niña running warmer than the stronger La Ninas. We probably have to wait until we get more clues in the fall. But every La Niña regardless of strength since 11-12 has been warmer than average in the Northeast. The stronger ones finished with a smaller warm departure than the weaker ones. Snowfall was more variable with the stronger events snowier than the weaker ones. This usually followed the October early MJO indicator. Plus we have had 9 warmer to record warm winters in a row following the new and warmer global temperature baseline following the 15-16 super El Niño. https://iri.columbia.edu/our-expertise/climate/forecasts/enso/2016-July-quick-look/?enso_tab=enso-sst_table ECMWF model -0.4 -0.3 -0.2 -0.2 -0.2

Looks like .90” at Fresh Kills in only 10 min. https://www.nysmesonet.org/networks/nyc

Yeah, close to the all-time highest dew points around your region today. The all-time highest temperatures missed to our south today. Glad you are getting better rainfall recently. RECORD EVENT REPORT NATIONAL WEATHER SERVICE RALEIGH NC 438 PM EDT FRI JUL 05 2024 ...ALL TIME RECORD HIGH TEMPERATURE SET AT RALEIGH NC... THE ALL TIME RECORD HIGH TEMPERATURE OF 106 DEGREES WAS SET AT RALEIGH NC TODAY. THIS BREAKS THE PREVIOUS ALL TIME RECORD HIGH OF 105 WHICH WAS SET MOST RECENTLY IN 2012. TODAY'S OLD RECORD OF 102 DEGREES WAS SET IN 1999.

We started to see a change during the 10-11 and 11-12 multiyear La Niña. 10-11 was one of our strongest La Ninas and best winters. The weaker 11-12 was much warmer and less snowy. Before this the weaker La Ninas were colder and snowier and the stronger ones warmer and less snowy.

Looks like 2nd highest dew point at SMQ on the hourly updates since records started in 1999. Not sure if those off hour 5 min higher obs at 81° were considered official. The chart below is only for hourly updates. https://www.weather.gov/wrh/timeseries?site=KSMQ&hours=72 https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=155&network=NJ_ASOS&zstation=SMQ&var=max_dwpf&w=all&threshold=100&hour=12&sdate=0101&edate=1231&month=jul&_r=t&dpi=100&_fmt=png

The weaker ONI La Ninas over the last decade have been warmer than the stronger ones. Not sure if we get a continuation of this theme going forward. But it will be interesting to see how things turn out.

SMQ is becoming the new Miami with dew points in the upper 70s again after last weekend. Somerville PTSUNNY 87 78

If the -PDO and marine heatwaves in those areas continue to be this strong going into the fall and winter, then it would probably mean a highly amplified Aleutian ridge. You can see the last frame of the Euro showing this. The recent CANSIPS was also moving toward this look in its recent update. So a very strong La Niña background state even if the ONI is only in La Nada to weak La Niña territory.

The Euro is similar to the SPC HREF next few days. Mid to upper 70s dew points and the potential for locally heavy downpours. Looks like the sea breeze boundaries and pre frontal trough will be the focus for convection and high dew point pooling.

I am guessing that the weaker Nino 3.4 and stronger -PDO are related to the current global record SSTs. We are just coming off a borderline super El Niño event so it naturally takes longer for Nino 3.4 to cool. This is what happened during the 16-17 La Niña following the 15-16 super El Niño. It took until the following season in 17-18 for the La Niña SSTs and ONI to drop lower. So the Euro rushed the cooling of Nino 3.4 from the forecasts issued back in the spring. The same way it tried to weaken the current marine heatwave east of Japan and south of the Aleutians. So both SST areas are now warmer in the recent forecast issued about an hour ago. The current record -PDO is allowing a much stronger La Niña atmospheric response than expected from just using the official ONI SSTs. As per the MJO details, we usually have to wait until at least October to get some hints as it’s usually less amplified during the warm season. New Euro run stronger marine heatwave south of Aleutians and east of Japan continuing to drive the stronger -PDO heading into fall Older run weaker marine heatwave south of Aleutians and -PDO and stronger La Niña cooling in Nino 3.4