May 2021

[donsutherland1]

Morning thoughts...

Today will be partly to mostly sunny and warm. Temperatures will likely reach the upper 70s to lower 80s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 79°

Newark: 83°

Philadelphia: 84°

A much warmer weekend lies ahead.

[SACRUS]

 

8 of the next  10 days look very warm with 3 - 4 90 degree readings, especially in the typical warmer locations in NJ.  Pending on clouds tomorrow, temps should soar into the upper 80s and low 90s, Sunday looks the same where temps could reach low 90s then followed by  sharp cooldown Monday , before warming back up Tue.  Wed  850 temps peak at >16c and mid 90s are possible in the hot spots .  By the  (5/27) perhaps the first widespread chance at rain with a cold front.  The Holiday weekend  looks warmer and we may see a spike of heat by Sun 5/30, pending on the ridge position.  Beyond there into early June it looks overall warm and we'll see if their is a transition to a wetter period. 

[bluewave]

While specific rainfall forecasts past 5 days can be low skill, the Euro has a chance of rain on Memorial Day weekend. Every Memorial Day weekend for the last 5 years had measurable rainfall one out of the three days. We just missed a deluge in 2015 with 3.73 on Tuesday May 31st at Newark.

Newark Memorial Day bolded

5-25-20…..5-23….0.79

5-27-19……5-26…0.20

5-28-18…..5-27….0.87

5-29-17…..5-29…..0.14

5-30-16……5-30…..1.57…….our last very dry spring

Tuesday 5-31-15……3.73

 

 

 

 

[nycwinter]

11 hours ago, CIK62 said:

 

The main models have an average high for the weekend of  89.5.        The EURO above has Zippo rain to go along with the above.

82 for monday lol

[SACRUS]

Gorgeous Califronia day out there.  72 sunny, dry and despite the pollen, lots of nice flowery , honey suckle smells all around.

[SACRUS]

13 minutes ago, nycwinter said:

82 for monday lol

Monday looks more like 60s sandwched between 90s on sunday and 80s by tuesday.

[bluewave]

Detroit was very close to the all-time May 500 mb height record this morning. Had we seen this anomalous a ridge during the summer, it would probably mean temperatures approaching or exceeding 100° In the Northeast. So it will be interesting to see if Newark can sneak in at least 95° max this month.

 

 

[Rtd208]

Current temp is 85 here. 

[IrishRob17]

Current temp is 87 here.

[crossbowftw3]

First 90 of the year here @ exactly 90 degrees at 4:31. Dew points aren't awful though but just enough to make it feel like the inside of a toaster out.

[doncat]

High of 80° today with the se wind.

[psv88]

High of 77 today, beautiful. Ready for the heat

[bluewave]

33 minutes ago, crossbowftw3 said:

First 90 of the year here @ exactly 90 degrees at 4:31. Dew points aren't awful though but just enough to make it feel like the inside of a toaster out.

Second May in a row up at BTV with a top three warmest monthly maximum temperature. 
 

RECORD REPORT
NATIONAL WEATHER SERVICE BURLINGTON VT
135 AM EDT FRI MAY 21 2021

...RECORD HIGH TEMPERATURE SET AT BURLINGTON VT...

A RECORD HIGH TEMPERATURE OF 92 WAS SET AT BURLINGTON VT YESTERDAY.
THIS BREAKS THE OLD RECORD OF 91 SET IN 1975.

 

Time Series Summary for Burlington Area, VT (ThreadEx) - Month of May
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Highest Max Temperature	Missing Count
1	2020	95	0
2	2017	93	0
-	1977	93	0
3	2021	92	11
-	2010	92	0
-	1987	92	0
-	1979	92	0
-	1978	92	0
-	1929	92	0
-	1911	92	0

[IrishRob17]

After a low of 48 made to 88 for the high. 

[Rtd208]

A little bit of a rollercoaster ride with temperatures coming up but overall warming up on average. I think the NYC metro has a pretty good chance of seeing triple digit temps this summer. Hopefully we will get some storminess at as well.

[LibertyBell]

1 hour ago, doncat said:

High of 80° today with the se wind.

ugh is that wind why my allergies are acting up for the first time all year?

 

[LibertyBell]

1 hour ago, bluewave said:

Second May in a row up at BTV with a top three warmest monthly maximum temperature. 
 

RECORD REPORT
NATIONAL WEATHER SERVICE BURLINGTON VT
135 AM EDT FRI MAY 21 2021

...RECORD HIGH TEMPERATURE SET AT BURLINGTON VT...

A RECORD HIGH TEMPERATURE OF 92 WAS SET AT BURLINGTON VT YESTERDAY.
THIS BREAKS THE OLD RECORD OF 91 SET IN 1975.

 

Time Series Summary for Burlington Area, VT (ThreadEx) - Month of May
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Highest Max Temperature	Missing Count
1	2020	95	0
2	2017	93	0
-	1977	93	0
3	2021	92	11
-	2010	92	0
-	1987	92	0
-	1979	92	0
-	1978	92	0
-	1929	92	0
-	1911	92	0

I'm betting we see our first 100 since 2013- finally a REAL SUMMER!  Hasn't happened in years.

 

[LibertyBell]

6 hours ago, bluewave said:

Detroit was very close to the all-time May 500 mb height record this morning. Had we seen this anomalous a ridge during the summer, it would probably mean temperatures approaching or exceeding 100° In the Northeast. So it will be interesting to see if Newark can sneak in at least 95° max this month.

 

 

We're all going to exceed 100 in July, finally getting a baker of a summer which I haven't seen in years!

 

[LibertyBell]

7 hours ago, SACRUS said:

Monday looks more like 60s sandwched between 90s on sunday and 80s by tuesday.

90s Saturday and Sunday and again on Wednesday?  Maybe even 95 on one or more of those days?

 

[LibertyBell]

20 hours ago, Dark Star said:

Too much rain - global warming.  Too little rain - global warming...

I like the too little rain, 70% of the world is covered in water, use it....

 

[doncat]

2 minutes ago, LibertyBell said:

ugh is that wind why my allergies are acting up for the first time all year?

 

I believe a wind off the ocean would help the air quality...I'm usually fine when it comes to allergies but my wife is bothered quite a bit.

[LibertyBell]

10 hours ago, bluewave said:

If the long range guidance is correct, then the humidity will probably increase as we head into June. So this is when we could start to see better chances for rain again. The record breaking ridge just to our west is acting as a block. EPS lifts the ridge axis north to near the Canadian Maritimes to start June. This is where the ridge axis was for the last 3 summers with the warm and moist onshore flow. So it will be interesting to see if we can make it 4 in a row.

EPS May 31- June 7 forecast 

 

No that is exactly what we DONT want.  What will it take to get a nice ridge set up like July 1993 and July 2010?  I want pure heat not taint with humidity.  I dont care about June since we dont see 100 in June, but July needs to be like it is right now.

 

 

[LibertyBell]

Just now, doncat said:

I believe a wind off the ocean would help the air quality...I'm usually fine when it comes to allergies but my wife is bothered quite a bit.

For some reason I have no allergies on a west or northwest wind, it's when the humidity goes up that I have problems with them.

 

[bluewave]

17 minutes ago, LibertyBell said:

No that is exactly what we DONT want.  What will it take to get a nice ridge set up like July 1993 and July 2010?  I want pure heat not taint with humidity.  I dont care about June since we dont see 100 in June, but July needs to be like it is right now.

 

 

It’s been tough to bet against the greatest 500mb height anomalies setting up over New England since 2018. The stronger ridging to our NE has allowed for higher dewpoints and  more onshore flow. If you want more westerly flow dry heat events like 2010 to 2013, then the best 500 mb anomalies need to be over the Great Lakes. 

 

 

[donsutherland1]

Temperatures in the northern Middle Atlantic and southern New England areas rose into the 70s and 80s today. Some 90° temperatures were reported. Burlington reached 90° for the second consecutive day and second time this month. Only 10 years saw May record 2 or more 90° temperatures and 9 years saw 2 or more consecutive such temperatures in May. The last time there were 2 or more 90° readings in May and 2 or more consecutive such temperatures was 2020. Syracuse reached 93°.

90° Days for Select Cities (through May 21):

Albany: 0 (2020: 13 days; 5-Year Average: 13.6 days)
Allentown: 0 (2020: 24 days; 5-Year Average: 27.6 days)
Baltimore: 0 (2020: 46 days; 5-Year Average: 44.6 days)
Boston: 0 (2020: 14 days; 5-Year Average: 17.2 days)
Bridgeport: 0 (2020: 11 days; 5-Year Average: 13.4 days)
Burlington: 2 (2020: 20 days; 5-Year Average: 13.0 days)
Harrisburg: 0 (2020: 35 days; 5-Year Average: 30.6 days)
Hartford: 0 (2020: 39 days; 5-Year Average: 29.0 days)
Islip: 0 (2020: 8 days; 5-Year Average: 9.4 days)
New York City-JFK: 0 (2020: 12 days; 5-Year Average: 10.2 days)
New York City-LGA: 0 (2020: 34 days; 5-Year Average: 29.4 days)
New York City-NYC: 0 (2020: 20 days; 5-Year Average: 18.2 days)
Newark: 1 (2020: 31 days; 5-Year Average: 31.2 days)
Philadelphia: 0 (2020: 36 days; 5-Year Average: 34.6 days)
Scranton: 1 (2020: 25 days; 5-Year Average: 16.4 days)
Washington, DC: 1 (2020: 46 days; 5-Year Average: 50.8 days)

New York City-Newark Average: 0 (2020: 22 days)
...Expected: 0 (based on regression equation tied to JFK-LGA-EWR data)
 
In Quebec, daily record high temperatures were set in Montreal: 89° (old record: 87°, 1977) and Trois-Rivières: 84° (old record: 79°, 2012)

Much warmer weather is likely for the weekend. Temperatures will generally reach the upper 80s and lower 90s across much of the region. Exceptions would be coastal areas prone to sea breezes.

The dominant weather story into at least the closing week of May will be the synoptic impact of a strongly to occasionally severely negative PNA. That development will lead to a warmer to perhaps much warmer than normal second half of May. There will likely be additional days on which the temperature will make a run at 90° in parts of the region.

Today, the preliminary value of the PNA was -1.457. The PNA is forecast to remain at or below -1.000 until around May 24. During the May 16-31, 1991-2020 period, the mean temperature was 65.2° in New York City and 67.0° in Philadelphia. When the PNA was -1.000 or below, the average temperature was 67.7° in New York City and 69.3° in Philadelphia.

During the 1991-2020 period, 30% of days in New York City and 41% of days in Philadelphia had high temperatures of 80° or above. During the 1991-2020 period, 15% of days in New York City and 23% of days in Philadelphia had high temperatures of 85° or above. When the PNA was -1.000 or below during that period, 41% of days in New York City and 50% of days in Philadelphia had high temperatures of 80° or above. When the PNA was -1.000 or below during that period, 24% of days in New York City and 35% of days in Philadelphia had high temperatures of 85° or above.

As had been the case with April, the closing week of May could wind up warmer to much warmer than normal. In the four cases where the MJO reached Phase 1 at an amplitude of 2.000 or above in combination with a cool ENSO Region 3.4 anomaly during the May 1-10 period, as occurred this year, three wound up with warmer to much warmer than normal conditions. At New York City, the mean temperature during the closing 7 days of May was 72.7° during those three cases while it was 72.0° at Philadelphia. The 1991-2020 means were 67.9° and 69.7° respectively. Only May 25-31, 2013 (monthly ENSO Region 1+2 anomaly of -1.38°C) was cooler than normal. However, 90° heat arrived on May 29 in Philadelphia and May 30 in New York City during 2013.

The first 7-10 days of June could also start off warmer than normal. The MJO's passage through Phase 4 at an amplitude of 1.500 or above during the May 15-25 period coupled with ENSO Region 1+2 temperature anomalies above -1.0°C and below +1.0°C, as has been the case this year, has typically seen warmth in the East during the first 10 days of June. Cooler conditions typically prevailed when the ENSO Region 1+2 anomalies were outside that range.

Neutral ENSO conditions have now developed. The ENSO Region 1+2 anomaly was -0.6°C and the Region 3.4 anomaly was -0.3°C for the week centered around May 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.75°C and the ENSO Region 3.4 anomaly has averaged -0.38°C. Neutral ENSO conditions will likely prevail into at least mid-summer.

The SOI was +0.86 today.

The preliminary Arctic Oscillation (AO) figure was -0.024 today.

On May 19 the MJO was in Phase 4 at an amplitude of 1.914 (RMM). The May 18-adjusted amplitude was 1.703 (RMM).

In late April, the MJO moved through Phase 8 at an extreme amplitude (+3.000 or above). Only February 25, 1988 and March 18-19, 2015 had a higher amplitude at Phase 8. Both 1988 and 2015 went on to have an exceptionally warm July-August period. July-August 1988 had a mean temperature of 79.1°, which ranked 4th highest for that two-month period. July-August 2015 had a mean temperature of 78.9°, which ranked 5th highest for that two-month period. September 2015 was also the warmest September on record. The MJO's extreme passage through Phase 8 could provide the first hint of a hot summer.

Based on sensitivity analysis applied to the latest guidance, there is an implied 84% probability that New York City will have a warmer than normal May (1991-2020 normal). May will likely finish with a mean temperature near 64.7° (1.5° above normal).

 

[LibertyBell]

1 hour ago, bluewave said:

It’s been tough to bet against the greatest 500mb height anomalies setting up over New England since 2018. The stronger ridging to our NE has allowed for higher dewpoints and  more onshore flow. If you want more westerly flow dry heat events like 2010 to 2013, then the best 500 mb anomalies need to be over the Great Lakes. 

 

 

I thought with the extended dry period we've had that would make the inland high more likely?  What's been causing the high to set up over new england anyway?

 

[LibertyBell]

6 minutes ago, donsutherland1 said:

Temperatures in the northern Middle Atlantic and southern New England areas rose into the 70s and 80s today. Some 90° temperatures were reported. Burlington reached 90° for the second consecutive day and second time this month. Only 10 years saw May record 2 or more 90° temperatures and 9 years saw 2 or more consecutive such temperatures in May. The last time there were 2 or more 90° readings in May and 2 or more consecutive such temperatures was 2020. Syracuse reached 93°.

90° Days for Select Cities (through May 21):

Albany: 0 (2020: 13 days; 5-Year Average: 13.6 days)
Allentown: 0 (2020: 24 days; 5-Year Average: 27.6 days)
Baltimore: 0 (2020: 46 days; 5-Year Average: 44.6 days)
Boston: 0 (2020: 14 days; 5-Year Average: 17.2 days)
Bridgeport: 0 (2020: 11 days; 5-Year Average: 13.4 days)
Burlington: 2 (2020: 20 days; 5-Year Average: 13.0 days)
Harrisburg: 0 (2020: 35 days; 5-Year Average: 30.6 days)
Hartford: 0 (2020: 39 days; 5-Year Average: 29.0 days)
Islip: 0 (2020: 8 days; 5-Year Average: 9.4 days)
New York City-JFK: 0 (2020: 12 days; 5-Year Average: 10.2 days)
New York City-LGA: 0 (2020: 34 days; 5-Year Average: 29.4 days)
New York City-NYC: 0 (2020: 20 days; 5-Year Average: 18.2 days)
Newark: 1 (2020: 31 days; 5-Year Average: 31.2 days)
Philadelphia: 0 (2020: 36 days; 5-Year Average: 34.6 days)
Scranton: 1 (2020: 25 days; 5-Year Average: 16.4 days)
Washington, DC: 1 (2020: 46 days; 5-Year Average: 50.8 days)

New York City-Newark Average: 0 (2020: 22 days)
...Expected: 0 (based on regression equation tied to JFK-LGA-EWR data)
 
In Quebec, daily record high temperatures were set in Montreal: 89° (old record: 87°, 1977) and Trois-Rivières: 84° (old record: 79°, 2012)

Much warmer weather is likely for the weekend. Temperatures will generally reach the upper 80s and lower 90s across much of the region. Exceptions would be coastal areas prone to sea breezes.

The dominant weather story into at least the closing week of May will be the synoptic impact of a strongly to occasionally severely negative PNA. That development will lead to a warmer to perhaps much warmer than normal second half of May. There will likely be additional days on which the temperature will make a run at 90° in parts of the region.

Today, the preliminary value of the PNA was -1.457. The PNA is forecast to remain at or below -1.000 until around May 24. During the May 16-31, 1991-2020 period, the mean temperature was 65.2° in New York City and 67.0° in Philadelphia. When the PNA was -1.000 or below, the average temperature was 67.7° in New York City and 69.3° in Philadelphia.

During the 1991-2020 period, 30% of days in New York City and 41% of days in Philadelphia had high temperatures of 80° or above. During the 1991-2020 period, 15% of days in New York City and 23% of days in Philadelphia had high temperatures of 85° or above. When the PNA was -1.000 or below during that period, 41% of days in New York City and 50% of days in Philadelphia had high temperatures of 80° or above. When the PNA was -1.000 or below during that period, 24% of days in New York City and 35% of days in Philadelphia had high temperatures of 85° or above.

As had been the case with April, the closing week of May could wind up warmer to much warmer than normal. In the four cases where the MJO reached Phase 1 at an amplitude of 2.000 or above in combination with a cool ENSO Region 3.4 anomaly during the May 1-10 period, as occurred this year, three wound up with warmer to much warmer than normal conditions. At New York City, the mean temperature during the closing 7 days of May was 72.7° during those three cases while it was 72.0° at Philadelphia. The 1991-2020 means were 67.9° and 69.7° respectively. Only May 25-31, 2013 (monthly ENSO Region 1+2 anomaly of -1.38°C) was cooler than normal. However, 90° heat arrived on May 29 in Philadelphia and May 30 in New York City during 2013.

The first 7-10 days of June could also start off warmer than normal. The MJO's passage through Phase 4 at an amplitude of 1.500 or above during the May 15-25 period coupled with ENSO Region 1+2 temperature anomalies above -1.0°C and below +1.0°C, as has been the case this year, has typically seen warmth in the East during the first 10 days of June. Cooler conditions typically prevailed when the ENSO Region 1+2 anomalies were outside that range.

Neutral ENSO conditions have now developed. The ENSO Region 1+2 anomaly was -0.6°C and the Region 3.4 anomaly was -0.3°C for the week centered around May 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.75°C and the ENSO Region 3.4 anomaly has averaged -0.38°C. Neutral ENSO conditions will likely prevail into at least mid-summer.

The SOI was +0.86 today.

The preliminary Arctic Oscillation (AO) figure was -0.024 today.

On May 19 the MJO was in Phase 4 at an amplitude of 1.914 (RMM). The May 18-adjusted amplitude was 1.703 (RMM).

In late April, the MJO moved through Phase 8 at an extreme amplitude (+3.000 or above). Only February 25, 1988 and March 18-19, 2015 had a higher amplitude at Phase 8. Both 1988 and 2015 went on to have an exceptionally warm July-August period. July-August 1988 had a mean temperature of 79.1°, which ranked 4th highest for that two-month period. July-August 2015 had a mean temperature of 78.9°, which ranked 5th highest for that two-month period. September 2015 was also the warmest September on record. The MJO's extreme passage through Phase 8 could provide the first hint of a hot summer.

Based on sensitivity analysis applied to the latest guidance, there is an implied 84% probability that New York City will have a warmer than normal May (1991-2020 normal). May will likely finish with a mean temperature near 64.7° (1.5° above normal).

 

Scranton hit 90 before Philly or Allentown?  Thats amazing- how? lol    I think they touched 90 yesterday?  What about Mt Pocono, Don?

[donsutherland1]

2 minutes ago, LibertyBell said:

Scranton hit 90 before Philly or Allentown?  Thats amazing- how? lol    I think they touched 90 yesterday?  What about Mt Pocono, Don?

MPO has not yet hit 90. 

[etudiant]

striking how LGA has so many more 90* days than NYC.  Is that because the NYC temperature is taken in Central Park, where the greenery tempers the heat?

[donsutherland1]

30 minutes ago, etudiant said:

striking how LGA has so many more 90* days than NYC.  Is that because the NYC temperature is taken in Central Park, where the greenery tempers the heat?

It was probably a combination of the increased urbanization around LGA--now New York City's premier heat island--and the more recent increase in vegation in Central Park. As a result, the relationship between the two locations weakened as far as 90° days was concerned.

Annual 90° Days (30-Year Average):
1951-80: LGA: 14.8; NYC: 18.3
1961-90: LGA: 13.7; NYC: 18.3
1971-00: LGA: 15.1; NYC: 18.1
1981-10: LGA: 18.7; NYC: 17.4
1991-20: LGA: 21.8; NYC: 17.4

The 30-year average for annual 90° days at LGA surpassed NYC for the first time during the 1978-2007 period.

Annual 90° Days (1950-2020 broken into two parts):
1950-1984: LGA: 14.7; NYC: 18.0 (coefficient of determination: 0.686)
1985-2020: LGA: 21.0; NYC: 17.5 (coefficient of determination: 0.619)