donsutherland1

June began on an unseasonably cool note. Low temperatures included: Allentown: 44° Bridgeport: 46° Islip: 44° New York City: 51° Newark: 51° Philadelphia: 51° Poughkeepsie: 39° White Plains: 42° Warmer weather will likely return by the middle of this week. At least several days with widespread high temperatures in the 80s will be likely. Nevertheless, no excessive heat is likely through at least the first ten days of June in the Middle Atlantic and southern New England regions. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.5°C for the week centered around May 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.03°C and the ENSO Region 3.4 anomaly has averaged 0.00°C. ENSO Region anomalies have continued to cool into the end of May. Neutral-cool conditions will likely prevail through mid-summer. The probability of the development of a La Niña event during late summer or early autumn has continued to increase. The SOI was +9.63 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.010. On May 31, the MJO was in Phase 1 at an amplitude of 1.849 (RMM). The May 30-adjusted amplitude was 1.784. June will likely have a temperature anomaly within 1° of normal (some areas on the cool side, others on the warm side) within the Middle Atlantic and southern New England regions.

May 2020 concluded with an estimated mean temperature of 60.3° in New York City. That made this May the coldest May since 2008 when the average temperature was 60.1°. June will start unseasonably cool with a morning temperature in the lower to middle 50s in New York City and 40s in some of the suburbs. Warmer weather should follow this latest cool shot. Late in the first week of June into the start of the second week of June, readings could be in the 80s in at least parts of the region. Nevertheless, no excessive heat is likely through at least the first ten days of June in the Middle Atlantic and southern New England regions. The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around May 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. ENSO Region anomalies have continued to cool into late May. Neutral-cool conditions will likely prevail through mid-summer. The probability of the development of a La Niña event during late summer or early autumn has increased. The SOI was +20.01 today. This is the first time the SOI has reached or exceeded +20.00 since August 10, 2019 when the SOI wsa +20.15. Today, the preliminary Arctic Oscillation (AO) figure was -1.165. On May 30, the MJO was in Phase 8 at an amplitude of 1.555 (RMM). The May 29-adjusted amplitude was 1.311. June will likely have a temperature anomaly within 1° of normal (some areas on the cool side, others on the warm side) within the Middle Atlantic and southern New England regions.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA 0.5 0.3 0.8 0.8 0.2 -0.3 1.5 1.2 -0.5 101 98 98 96 99 104 97 118 94

Following today's warmth, cooler air will move into the region for a few days. Warmer weather should follow the cool shot. Late in the first week of June into the start of the second week of June, readings could be in the 80s in at least parts of the region. Nevertheless, no excessive heat is likely through at least the ten days of June in the Middle Atlantic and southern New England regions. The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around May 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. ENSO Region anomalies have continued to cool into late May. Neutral-cool conditions will likely prevail through mid-summer. The probability of the development of a La Niña event during late summer or early autumn has increased. The SOI was +17.79 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.352. On May 29, the MJO was in Phase 8 at an amplitude of 1.310 (RMM). The May 28-adjusted amplitude was 1.367. June will likely have a temperature anomaly within 1° of normal (some areas on the cool side, others on the warm side) within the Middle Atlantic and southern New England regions. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.3°. That would be the coolest May since 2008 when the monthly temperature was also 60.1°.

Under bright sunshine, the temperature again rose into the 80s in many parts of the region. On a separate note, the goslings have arrived.

The afternoon turned out mostly sunny,windy and warm across the region. Highs generally reached the upper 70s to the middle 80s. A few areas in Quebec continued to experience record warmth. Records included: Gaspé: 89° (old record: 86°, 1968) Îles de la Madeleine: 72° (old record: 71°, 1992) Rivière-du-Loup: 85° (old record: 80°, 1972) Yesterday's final data revealed that Îles de la Madeleine set a new May record high temperature of 78°(25.4°C). For the Middle Atlantic and southern New England regions, no excessive heat is likely through at least the first week in June. A fresh cool shot could arrive as May concludes and June commences. Warmer weather should follow the cool shot. Late in the first week of June into the start of the second week of June, readings could be in the 80s in at least parts of the region. The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around May 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. ENSO Region anomalies have continued to cool into late May. Neutral-cool conditions will likely prevail through mid-summer. The probability of the development of a La Niña event during late summer or early autumn has increased. The SOI was +8.90 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.320. On May 28, the MJO was in Phase 8 at an amplitude of 1.366 (RMM). The May 27-adjusted amplitude was 1.485. June will likely have a temperature anomaly within 1° of normal (some areas on the cool side, others on the warm side) within the Middle Atlantic and southern New England regions. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.2°. That would be the coolest May since 2008 when the monthly temperature was also 60.1°.

The afternoon turned out mainly sunny, breezy and warm:

Tomorrow will be another mostly cloudy day. Some sunshine could break through. In addition, some showers and perhaps thundershowers are also possible. Readings could rise well into the 70s. Parts of Quebec continued to experience unseasonable heat. Based on preliminary data, Îles de la Madeleine set a new May record high temperature of 77°(old record: 73°, 2001). The final data from yesterday for Montreal and Quebec City revealed that both cities set May records and Montreal had its second highest temperature on record. Montreal: 36.6°C/98°F ***New May Record*** Quebec City: 33.1°C/92°F *** New May Record*** For the Middle Atlantic and southern New England regions, no excessive heat is likely through at least the first week in June. Moreover, a fresh cool shot could arrive as May concludes and June commences. The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around May 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. ENSO Region anomalies have continued to cool into late May. Neutral-cool conditions will likely prevail through mid-summer. The probability of the development of a La Niña event during late summer or early autumn has increased. The SOI was +1.55 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.581. On May 27, the MJO was in Phase 7 at an amplitude of 1.484 (RMM). The May 26-adjusted amplitude was 1.316. June will likely have a temperature anomaly within 1° of normal (some areas on the cool side, others on the warm side) within the Middle Atlantic and southern New England regions. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.2°. That would be the coolest May since 2008 when the monthly temperature was also 60.1°.

Early this evening, the temperature was near 70° and a gusty southerly wind blew in from over the Long Island Sound. There was even some light drizzle.

I missed the 37.6C reading. Yesterday’s high was 36.6C not 35.8C. That was the second highest figure on record.

Throughout much of this month, the GFS has often shown the development of heat in the extended range only to see the heat not materialize. It's unclear, but possible, that the partial fix for the wintertime cold bias/snowfall bias in the FV3 core might be responsible.

Montreal's 98 degree high yesterday set a new all-time record . The old record was 97 degrees from August 8, 2001.

As had been the case yesterday, clouds broke for sunshine and temperatures rose into the upper 70s across much of the region. Tomorrow will likely be mostly cloudy with a few scattered showers and cooler as the remnants of Tropical Storm Bertha pass well to the west of the region. Parts of Upstate New York, northern New England, Quebec and Ontario saw record heat. In some places, new May records were set. High temperatures included: Burlington: 95° (old record: 91°, 1944 and 2016) ***New May Record*** Caribou: 87° Montreal: 96° (old record: 89°, 1978 and 2016) ***New May Record*** Ottawa: 95° (old record: 93°, 1914) Quebec City: 90° Saranac Lake, NY: 93° (old record: 88°, 1914) Montreal's 96° (35.8°C) temperature was the hottest temperature recorded anywhere in Canada today. Some of those areas could see near record to record warmth again tomorrow. Much cooler air will arrive there for the coming weekend. No excessive heat appears likely through at least the first week in June in the Middle Atlantic and southern New England regions. Moreover, a fresh cool shot could arrive as May concludes and June commences. The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around May 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. ENSO Region anomalies have continued to cool into late May. Neutral-cool conditions will likely prevail through mid-summer. The probability of the development of a La Niña event during late summer or early autumn has increased. The SOI was -6.34 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.799. On May 26, the MJO was in Phase 7 at an amplitude of 1.315 (RMM). The May 25-adjusted amplitude was 1.276. Uncertainty still exists with regard to June. However, the recent guidance has begun to converge on a scenario where the temperature anomaly would be within 1° of normal (some areas on the cool side, others on the warm side) within the region. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.1°. That would be the coolest May since 2008 when the monthly temperature was also 60.1°.

This afternoon, temperatures again soared well into the 70s under abundant sunshine.

That’s not accurate. Its all-time high is 101 degrees, which was set on June 29, 1933.

Montreal further extended its all-time May record with a 3 pm temperature of 35.5 degrees C (96 degrees F).

Burlington reached 94 degrees at 3 pm. That surpassed the daily record( 91 degrees set in 1944 and tied in 2016) and monthly record (93 degrees set on May 22, 1977 and tied on May 18, 2017).

At 2 pm, the temperature was 35 degrees C (95 degrees F) in Montreal. That surpassed the previous May record of 34.7 degrees C (94 degrees F), which was set on May 26, 2010.

At 1 pm, the temperature was 33.4 degrees C (92 degrees F) in Montreal. That broke the daily record of 31.7 degrees C (89 degrees F), which was set in 1978 and tied in 2016.

Monthly record is 93 (May 22, 1977 and May 17, 2017). Montreal and Quebec City might also make a run at their May records.

Quebec City also had an earlier first 90 degree reading (May 20, 1911).

Yes. For example, Burlington had a high temperature of 90 on May 11, 1911 (NYC was 76). NYC’s first 90 degree temperature occurred on July 2, 1911. On May 23, 1975 Montreal had a high temperature of 90. New York City’s first 90 degree temperature occurred a day later on May 24.

Clouds again gave way to sunshine today. In response, the temperature rose into the upper 70s in New York City and nearby areas. Across Western and Upstate New York, record high temperatures were set. Near record heat also prevailed in parts of Ontario and Quebec. High temperatures included: Buffalo: 92° (old record: 88°, 1944) Burlington: 92°(tied record set in 2010) Caribou: 87° Montreal: 91° Ottawa: 92° Rochester: 91° (old record: 90°, 1944) Syracuse: 93° (old record: 90°, 2010 and 2011) Some of those areas could see record warmth again tomorrow. No excessive heat appears likely for at least the next 10-14 days in the Middle Atlantic and southern New England regions. Moreover, a fresh cool shot could arrive as May concludes and June commences. The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around May 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. ENSO Region anomalies have continued to cool into late May. Neutral-cool conditions will likely prevail through mid-summer. The probability of the development of a La Niña event during late summer or early autumn has increased. The SOI was -6.34 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.127. On May 25, the MJO was in Phase 6 at an amplitude of 1.279 (RMM). The May 24-adjusted amplitude was 1.599. Uncertainty still exists with regard to June. However, the recent guidance has begun to converge on a scenario where the temperature anomaly would be within 1° of normal (some areas on the cool side, others on the warm side) within the region. Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.1°. That would be the coolest May since 2008 when the monthly temperature was also 60.1°.

Under bright afternoon sunshine and a nearly cloudless sky, the temperature soared into the upper 70s this afternoon. Two photos:

Tomorrow will again see clouds yield to sunshine. Warmer temperatures appear likely during the closing days of May. However, no excessive heat appears likely for at least the next 10-14 days. Moreover, a fresh cool shot could arrive as May concludes and June commences. The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around May 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.20°C. ENSO Region anomalies have continued to cool into late May. Neutral-cool conditions will likely prevail through mid-summer. The probability of the development of a La Niña event during late summer or early autumn has increased. The SOI was -3.58 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.151. On May 24, the MJO was in Phase 6 at an amplitude of 1.605 (RMM). The May 23-adjusted amplitude was 1.645. Considerable uncertainty exists with regard to June. The May 21 0z EPS weeklies remained consistent with earlier EPS guidance favoring a cooler than normal June. The CFSv2 has been very consistent in showing an area of warm anomalies in the Northeast. However, the CFSv2 is just nearing its skillful range. Based on sensitivity analysis applied to the latest guidance, there is an implied 97% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.2°.