bluewave

Should be fun. The HRES is still produced and disseminated. It is meteorologically equivalent to the ENS 'control', but due to some technical and configuration differences, it does not provide completely identical outputs. The HRES runs for 10 days, while the ENS control runs for 15, and the HRES is disseminated earlier than the full ensemble forecast. Our aim is to stop using the term ‘high-resolution forecast’, or HRES, as all members of the ensemble are now also at 9 km horizontal resolution. For the next IFS upgrade, Cycle 49r1, planned for October 2024, the HRES and the ENS control are being made bit identical. Both will run to 15 days for 00 and 12 UTC. From IFS Cycle 50r1, planned for October 2025, we will stop producing the current ENS control, and the data stream that is currently called the HRES will be called ‘ENS control’ instead. This single, unperturbed forecast will continue to be made available earlier than the ensemble perturbed members, in line with the agreed dissemination schedule.

It has a long range cold bias so far and will probably trend warmer like it did for the storm this weekend.

Yeah, this was also the warmest winter on record for the Northeast. First time time the region had 9 consecutive warmer than average winters in a row. With 5 top 10 warmest winters since 15-16.

Yeah, there have been many comments on the forum how this -PDO La Niña background state has been so much warmer especially during the winters than older -PDO La Niña years before 15-16. I think the record SST warming near Japan is going hand in hand with the warming in the MJO 4-7 areas. So both those features tend to promote an Aleutian ridge near the Dateline and a ridge near the Eastern US. Notice how even with such a strong El Niño this winter there was still that ridge south of the Aleutians instead of the much stronger Aleutian low typical for strong El Niños.

This is a much warmer version of the -PDO for us defined more by the record marine heatwave near Japan than the cold ring off of California.

Airports are just as good if not better for measuring snowfall and temperatures than the neighborhoods that are nearby. The actual ASOS is away from the concrete on grassy strips like a backyard in the adjacent neighborhoods. Those local neighborhoods also have streets and driveways which are also made of concrete. We could make the case that our local airports probably aren’t the warmest spots in our area since they are located very close to the water which are subject to cooling sea breezes during the summer. There are places more inland of Newark with more 90° days. Newark only ranks 4th in 90° days since 2010 due to the breezes off the bay since the ASOS is right on the water. Data for January 1, 2010 through December 31, 2022 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 HIGHTSTOWN 2 W COOP 465 HARRISON COOP 459 FREEHOLD-MARLBORO COOP 453 Newark Area ThreadEx 439 NEWARK LIBERTY INTL AP WBAN 439 CANOE BROOK COOP 438 New Brunswick Area ThreadEx 414 NEW BRUNSWICK 3 SE COOP 414

While LGA didn’t have the undermeasurement issues since they use professional contract observers, this was still the lowest 2 year snowfall on record for LGA. A 2 year average of only 7.0 and total of 13.9 was a new record low. Combined with consecutive winters above 40° this was officially the least winter-like 2 year period on record. Time Series Summary for LAGUARDIA AIRPORT, NY - Oct through Sep Click column heading to sort ascending, click again to sort descending. Rank Season Total Snowfall Missing Count 1 1972-1973 1.9 0 2 2022-2023 3.4 0 - 2001-2002 3.4 0 3 1941-1942 3.6 0 4 2019-2020 4.6 0 5 2011-2012 5.1 0 6 1997-1998 7.1 0 7 1979-1980 10.3 0 8 2023-2024 10.5 208 9 1988-1989 10.8 0 10 2007-2008 11.2 0 - 1996-1997 11.2 0 Time Series Summary for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Season Mean Avg Temperature Missing Count 1 2001-2002 41.9 0 2 2015-2016 41.6 0 3 2022-2023 40.9 0 - 2016-2017 40.9 0 4 2011-2012 40.7 0 5 2023-2024 40.3 0

It’s the accumulated cyclone energy. The early seasonal forecasts indicate we have a shot at 160+. But the predominant storm tracks will be the most important for the actual impacts. Accumulated Cyclone Energy - Atlantic hide Season ACE TS HU MH Classification 1933 258.57 20 11 6 Extremely active 2005 245.3 28 15 7 Extremely active 1893 231.1475 12 10 5 Extremely active 1926 229.5575 11 8 6 Extremely active 1995 227.1025 19 11 5 Extremely active 2004 226.88 15 9 6 Extremely active 2017 224.8775 17 10 6 Extremely active 1950 211.2825 16 11 6 Extremely active 1961 188.9 12 8 5 Extremely active 1998 181.7675 14 10 3 Extremely active 1887 181.26 19 11 2 Extremely active 1878 180.85 12 10 2 Extremely active 2020 180.3725 30 14 7 Extremely active 2003 176.84 16 7 3 Extremely active 1999 176.5275 12 8 5 Extremely active 1932 169.6625 15 6 4 Extremely active 1996 166.1825 13 9 6 Extremely active 1886 166.165 12 10 4 Extremely active 1969 165.7375 18 12 3 Extremely active 2010 165.4825 19 12 5 Extremely active 1906 162.88 11 6 3 Extremely active

This rough pattern for the beaches looks to continue right into the fall. Record Atlantic SSTs plus a developing La Niña. So we could be looking at a high number of named storms and ACE. Even if the strongest landfall impacts are down around the SE and Gulf, the beaches aren’t ready for a big hurricane swell season. Closer landfalls would be even worse since many spots are in such bad shape. Not to mention the flooding from rainfall should high amounts of tropical moisture stream into our region like we saw a few summers ago.

Could be some more beach erosion this weekend as the next storm coincides with the higher astronomical tides at the time of the new moon. But the period of onshore flow should be of shorter duration then some of the stronger recent erosion events. The offshore flow from Sunday into Monday should be more prolonged and stronger with gusts in excess of 50 mph possible as the low closes off near Maine.

I get them from the Frontierweather DTN site. https://frontierweather.dtn.com/verification-iframe.html

Currently the lowest number of freezes by one day ahead of the previous record holder last winter. If NYC can hold onto 3-1 as the latest feeeze, it would be the 2nd earliest by a few days. 2020 was the last time NYC had a last freeze on March 1st. 2024-03-01 48 30 39.0 0.2 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Min Temperature <= 32 Oct 1 to Apr 30 Missing Count 1 2024-04-30 36 55 2 2023-04-30 37 0 - 2012-04-30 37 0 3 2002-04-30 47 0 4 2020-04-30 48 0 - 2016-04-30 48 0 5 2017-04-30 49 0 - 1998-04-30 49 0 Frost/Freeze Summary for NY CITY CENTRAL PARK, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length 1942 02-28 (1942) 29 11-13 (1942) 31 257 2020 03-01 (2020) 25 10-31 (2020) 32 243 1962 03-09 (1962) 32 11-07 (1962) 31 242 1945 03-11 (1945) 32 11-21 (1945) 31 254 1953 03-11 (1953) 21 11-06 (1953) 30 239 1946 03-12 (1946) 28 11-23 (1946) 31 255

My guess is that the long range model error is the inability of the models to resolve the MJO. So this introduces a significant cold bias. Convection keeps reloading in the warm phases. The stock El Niño seasonal default doesn’t normally include so much MJO 4-7 action. In the old days, the MJO was weak or inactive in these phases during stronger El Niño’s. So the record WPAC warm pool is competing with the typical El Niño warm pool. The long range models must not be able to give reliable long range forecasts when there are other marine heatwaves competing with the El Niño. All forecasts beyond a week or two have been defaulting to the stock El Niño seasonal forecasts issued in November with that big Southeast El Nino trough which didn’t verify this winter. WPAC forcing promotes more of a ridge in these areas.

It’s good to see AI versions of these models coming out. The hope is that they can correct the day 11-15 cold bias of all the major models. It will be interesting to see if AI can be used to correct the long range tendency for models to underestimate the warmer MJO forcing. That’s a big part of why the week 2 and beyond forecasts have been up to 5° too cold in spots going back to late November.

Many stations from Newark to Boston had their lowest 2 year snowfall totals and averages on record. It’s a bit of a surprise this took so long to achieve with how warm the winters have been getting. Very little we can do when record warmth combines with a very hostile Pacific. Plus we did this with a La Niña last winter and El Niño this year. The SSWs and Atlantic blocking intervals this winter we’re no match for the warm MJO action. Same for the near record -AO in December 2022 and strong blocking pattern last March. The Pacific has just become to powerful a force in terms of flooding North America with warmth and producing unfavorable storm tracks.

Much above average temperatures continuing well into March. While it looks like the highest departures remain west, a 70° day or two can always sneak in with enough sun and SW flow. This may be something that pops up in the short term when the finer details are known. Models trying to show some closer to average temperatures in around 15 days. But the very warm Gulf Stream appears to be keeping the region from getting too cold even if more of a trough develops.

5th warmest start to March around +10. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Mar 1 to Mar 5 Missing Count 1 1991-03-05 52.1 0 2 2004-03-05 51.5 0 3 1880-03-05 48.9 0 4 1964-03-05 48.8 0 5 2024-03-05 48.7 0 6 1974-03-05 47.4 0 7 1882-03-05 47.3 0 8 1973-03-05 46.8 0 - 1961-03-05 46.8 0 9 2020-03-05 46.6 0 - 1979-03-05 46.6 0 - 1919-03-05 46.6 0 10 1983-03-05 46.3 0

Yeah, the extended Euro continues with the wet pattern until further notice.

Hard to believe that there hasn’t been a major hurricane landfall north of the Gulf and FL since 1996. Must be related to the stronger ridge east of New England steering many systems to the south. While Sandy’s damage resembled a major, it went in near ACY instead of New England. https://www.aoml.noaa.gov/hrd/hurdat/All_U.S._Hurricanes.html

It will be interesting to see if the Euro is correct about the enhanced tropical activity from the Caribbean into the Gulf.

Plenty of extra Atlantic warmth and moisture to fuel more heavy rains.

Yeah, we would be in the 70s today like areas to our west if we had sun and SW flow.

Hopefully the models are correct and we can sneak in another 70° day next week after all the rain through the coming weekend.

Yeah, any days with offshore flow and enough sun will make a run on 70° like we got yesterday and Buffalo is getting today. But the key is enough sun and offshore flow. These slight nuisances which allow 70° warmth are best dealt with by the shorter term models within a few days. This current pattern is a very wet and warm with numerous opportunities for onshore flow. So the minimum warm departures may end up may end up being higher than the max departures next few weeks. As for calls for cooler later in the month, we have to remember how the models have had a cooler weather near the end of their range all winter only to correct warmer in time.