April 2020

[donsutherland1]

Yesterday, 5.5" snow fall at Caribou. That exceeded the previous daily record of 4.6", which was set in 1989. Seasonal snowfall has now reached 146.0", which is the 9th highest figure on record. In addition, the total snowfall for the last two seasons (2018-19 through 2019-20) is 311.4", which is the second highest such figure on record. Only 2007-08 through 2008-09 with 313.5" had more.

A storm coming out of the Ohio Valley will bring showers and periods of rain tonight and tomorrow. Temperatures will likely stay well below normal through tomorrow.

Overall, readings will likely average generally below normal to near normal with a few warmer than normal days across the Middle Atlantic and southern New England regions through most of the remainder of the month. Warmer than normal conditions could return near the end of the month or just afterward.
 
Past cases that saw the NAO average -0.750 or below during April 1-5 with warmth in the East, as occurred this month, saw the development of a trough in the East after April 10. That trough typically persisted in the means for 1-2 weeks.

Looking ahead to May, 73% of cases that saw one or more days where the NAO fell to -1.000 or below during April 1-10, 1950-2019, as was the case this April, wound up with a warmer than normal May. However, uncertainty about the May outcome has increased. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer.

The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around April 8. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.55°C and the ENSO Region 3.4 anomaly has averaged +0.62°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May.

The SOI was +1.87 today.

Today, the preliminary Arctic Oscillation (AO) figure was +0.217.

On April 22, the MJO was in Phase 2 at an amplitude of 1.793 (RMM). The April 21-adjusted amplitude was 1.796.

February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Based on recent MJO data, the probability of a warmer than normal summer has increased. Such a summer is now likely in much or all of the East.

Based on sensitivity analysis applied to the latest guidance, there is an implied 91% probability that New York City will have a cooler than normal April. April will likely finish with a mean temperature near 51.5°.

 

[JerseyWx]

3 hours ago, hudsonvalley21 said:

And next Thursday too. Pretty wet 7 day QPF map.

 

Yep, you're right, middle of next week looks unsettled too. 

[SRRTA22]

I got rain with occasional sleet mixed in

[CIK62]

The last 7 days of April are averaging 53degs., or about 5degs. BN.

Month to date is  -1.5[50.4].          April should end near  -2.1[50.9].

45* here at 6am.(wet, drizzle)          47* by 10am, Rain.        48* by 1pm.          50* by 2pm.         51* or -50* bet. 4pm-7pm.

[wxallannj]

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 Apr 16 to Apr 23	Missing Count
1	1940-04-23	44.6	0
2	1943-04-23	44.7	0
3	2020-04-23	45.9	0
4	1947-04-23	46.1	0
5	1983-04-23	46.5	0

[Animal]

Picked up 0.27 of rain overnight.

[qg_omega]

10 hours ago, donsutherland1 said:

Yesterday, 5.5" snow fall at Caribou. That exceeded the previous daily record of 4.6", which was set in 1989. Seasonal snowfall has now reached 146.0", which is the 9th highest figure on record. In addition, the total snowfall for the last two seasons (2018-19 through 2019-20) is 311.4", which is the second highest such figure on record. Only 2007-08 through 2008-09 with 313.5" had more.

A storm coming out of the Ohio Valley will bring showers and periods of rain tonight and tomorrow. Temperatures will likely stay well below normal through tomorrow.

Overall, readings will likely average generally below normal to near normal with a few warmer than normal days across the Middle Atlantic and southern New England regions through most of the remainder of the month. Warmer than normal conditions could return near the end of the month or just afterward.
 
Past cases that saw the NAO average -0.750 or below during April 1-5 with warmth in the East, as occurred this month, saw the development of a trough in the East after April 10. That trough typically persisted in the means for 1-2 weeks.

Looking ahead to May, 73% of cases that saw one or more days where the NAO fell to -1.000 or below during April 1-10, 1950-2019, as was the case this April, wound up with a warmer than normal May. However, uncertainty about the May outcome has increased. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer.

The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around April 8. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.55°C and the ENSO Region 3.4 anomaly has averaged +0.62°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May.

The SOI was +1.87 today.

Today, the preliminary Arctic Oscillation (AO) figure was +0.217.

On April 22, the MJO was in Phase 2 at an amplitude of 1.793 (RMM). The April 21-adjusted amplitude was 1.796.

February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Based on recent MJO data, the probability of a warmer than normal summer has increased. Such a summer is now likely in much or all of the East.

Based on sensitivity analysis applied to the latest guidance, there is an implied 91% probability that New York City will have a cooler than normal April. April will likely finish with a mean temperature near 51.5°.

 

When do you expect a pattern shift then, I see no signs of the current below normal pattern shifting.  It seems locked in for the next few weeks with below normal temperatures and well above normal precipitation

[MJO812]

Caribou has been getting more snow than alot of the lake regions lately.

[bluewave]

Models continuing with the Eastern Trough right into May. 

April so far

Forecast

 

 

 

[uncle W]

41 minutes ago, bluewave said:

Models continuing with the Eastern Trough right into May. 

April so far

Forecast

 

 

 

its been a long time since NYC had temperatures in the 30's in May...1978 was the last year that happened...1976-77-78 all had temps in the 30's in May...

[bluewave]

18 minutes ago, uncle W said:

its been a long time since NYC had temperatures in the 30's in May...1978 was the last year that happened...1976-77-78 all had temps in the 30's in May...

Yeah, that record has been tough to beat. Numerous low 40’s for the May monthly minimum temperature. With all the rain in the forecast, the cooler maximums  will probably be more impressive for NYC than the minimums. 
 

TEMPERATURE (F)
 YESTERDAY
  MAXIMUM         52    341 PM  86    2007  64    -12       77
  MINIMUM         40    820 AM  29    1872  47     -7       56
  AVERAGE         46                        56    -10       67

 

[uncle W]

7 minutes ago, bluewave said:

Yeah, that record has been tough to beat. Numerous low 40’s for the May monthly minimum temperature. With all the rain in the forecast, the cooler maximums  will probably be more impressive for NYC than the minimums. 
 

TEMPERATURE (F)
 YESTERDAY
  MAXIMUM         52    341 PM  86    2007  64    -12       77
  MINIMUM         40    820 AM  29    1872  47     -7       56
  AVERAGE         46                        56    -10       67

 

when I first started observing weather in 1962 May 62 had three days with a max in the 40's...then on the 19th there was a heat wave...back in 1987 there was a day in the 40's and my house was cold...the heat was shut off weeks before...I think last year had a day with a max in the 40's...

[SnowGoose69]

1 hour ago, bluewave said:

Models continuing with the Eastern Trough right into May. 

April so far

Forecast

 

 

 

The good news is it'll change.  Much like winter it seems if you're really cold in April/May you rarely have a cool summer.  The only cases I know of where this really held the whole way through were 83 and 96 and I want to say 96 actually was fairly mild from 5/1-6/15 but it flipped right after that.

[qg_omega]

1 hour ago, bluewave said:

Models continuing with the Eastern Trough right into May. 

April so far

Forecast

 

 

 

One month late

[coastalplainsnowman]

Hoping this spring doesn't shape up to be like 2003 around here.  If memory serves, it was the last week of June before the damp / cold bite was out of the air for good.

[Allsnow]

Knyc -1.5 MTD 

[uncle W]

44 minutes ago, coastalplainsnowman said:

Hoping this spring doesn't shape up to be like 2003 around here.  If memory serves, it was the last week of June before the damp / cold bite was out of the air for good.

it was the first year since the 1920's to have April average in the 40's...May in the 50's and June in the 60's...has not come close since...

[SI Mailman]

The good news is it'll change.  Much like winter it seems if you're really cold in April/May you rarely have a cool summer.  The only cases I know of where this really held the whole way through were 83 and 96 and I want to say 96 actually was fairly mild from 5/1-6/15 but it flipped right after that.

There was a string of 90 degree days in mid to late May in 96. I remember because my family was in the process of moving and all my summer clothes were in storage.

[Rtd208]

Picked up 0.05" of rain for the day yesterday, 0.58" so far today.

Storm total so far 0.63"

Current temp 47

[Stormlover74]

10th straight below average day. 15 seems like a sure thing, wonder if we can make it to 20

[NorthShoreWx]

For  the statisticians in this group, when was the last time the warmest temperature in January was warmer than the warmest temperature in April?  There's a good shot at it for both NYC and ISP.

[bluewave]

26 minutes ago, NorthShoreWx said:

For  the statisticians in this group, when was the last time the warmest temperature in January was warmer than the warmest temperature in April?  There's a good shot at it for both NYC and ISP.

This would be a first.

Monthly Highest Max Temperature for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Jan	Feb	Mar	Apr	Season
2020	69	62	77	68	77

 

Monthly Highest Max Temperature for ISLIP-LI MACARTHUR AP, NY
Click column heading to sort ascending, click again to sort descending.

Year	Jan	Feb	Mar	Apr	Season
2020	68	54	70	64	70

 

Monthly Highest Max Temperature for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

Year	Jan	Feb	Mar	Apr	Season
2020	70	62	80	69	80

 

[uncle W]

1 hour ago, NorthShoreWx said:

For  the statisticians in this group, when was the last time the warmest temperature in January was warmer than the warmest temperature in April?  There's a good shot at it for both NYC and ISP.

never happened before...1874 and 1876 missed by one degree of tying...

[SnoSki14]

It has felt like March since December.

Ironically March this year felt more like mid-late Spring.

[uncle W]

20 hours ago, uncle W said:

no snow reported on the daily almanac for NYC...its only a trace but it should have been observed...

all the airports reported a trace of snow yesterday...A man walking his dog in Central Park saw snow and sleet falling...a trace of snow on 4/23 is a significant event but it went unobserved...

[Cfa]

7 minutes ago, uncle W said:

all the airports reported a trace of snow yesterday...A man walking his dog in Central Park saw snow and sleet falling...a trace of snow on 4/23 is a significant event but it went unobserved...

What exactly constitutes a trace?

[NorthShoreWx]

6 minutes ago, Cfa said:

What exactly constitutes a trace?

1 wet flake reaching the ground is a trace.  It's anything more than nothing but less than measureable (i.e., a tenth of an inch is measureable).

I observed a trace at my location yesterday.  It snowed lightly for about 30 minutes but melted on contact with the ground.

 

[Cfa]

37 minutes ago, NorthShoreWx said:

1 wet flake reaching the ground is a trace.  It's anything more than nothing but less than measureable (i.e., a tenth of an inch is measureable).

I observed a trace at my location yesterday.  It snowed lightly for about 30 minutes but melted on contact with the ground.

 

Thanks. I’d always thought of it as more of a light coating of less than 0.1”, didn’t know a couple of melted flakes fit the definition as well.

[doncat]

0.82" storm total...High temp 49° ,  Normal 64°.

[donsutherland1]

12 hours ago, qg_omega said:

When do you expect a pattern shift then, I see no signs of the current below normal pattern shifting.  It seems locked in for the next few weeks with below normal temperatures and well above normal precipitation

There will be some changes to start May, but they don't appear too big right now.