April 2021

[donsutherland1]

2 hours ago, LibertyBell said:

Don, this has been one of the colder Aprils, I've had my heat on all month and it looks like more cold is coming.  Isn't it going to be difficult to have an above normal month?

 

All of the NYC area sites are currently running above normal through yesterday:

EWR: +1.1

JFK: +1.3

LGA: +2.2

NYC: +1.8

This week's brief cold shot won't be sufficient to erase these warm anomalies. Moreover, today and tomorrow could add to those warm anomalies.

[donsutherland1]

2 hours ago, LibertyBell said:

Looks like the accumulating snow will make it to KC, Chicago, Detroit, Cleveland and Buffalo? What about the NE PA mountains Don?  Lows in the 20s are being predicted there.

Also with all this cold around all month how will we get an above normal month?

 

It's possible that some of the NE PA mountains could pick up a coating of snow.

[LibertyBell]

17 minutes ago, donsutherland1 said:

All of the NYC area sites are currently running above normal through yesterday:

EWR: +1.1

JFK: +1.3

LGA: +2.2

NYC: +1.8

This week's brief cold shot won't be sufficient to erase these warm anomalies. Moreover, today and tomorrow could add to those warm anomalies.

ah okay, it doesn't feel that warm because we have had no 80s (and barely any 70s and low 70s at that) and I've had the heat on every day.

The min thing always taints the average, it never feels that warm unless the high temp is 70+ on a consistent basis.

 

[LibertyBell]

1 hour ago, donsutherland1 said:

Morning thoughts...

Today will be partly sunny and warm. High temperatures will likely reach the middle and upper 60s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 66°

Newark: 67°

Philadelphia: 68°

Tomorrow will be sunny unseasonably warm. Temperatures will likely reach or exceed 70° in much of the region.

At the same time, a storm could bring 1”-3” of snow to Detroit on tomorrow into Wednesday. Detroit’s most recent measurable snow on or after April 20 occurred on May 10, 2020 when 0.5” of snow fell. 

Detroit’s daily snowfall records are:

April 20: 1.2”, 1947

April 21: 0.3”, 1978

even more surprising would be accumulating snow for both KC and St Louis!

[LibertyBell]

1 hour ago, donsutherland1 said:

Morning thoughts...

Today will be partly sunny and warm. High temperatures will likely reach the middle and upper 60s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 66°

Newark: 67°

Philadelphia: 68°

Tomorrow will be sunny unseasonably warm. Temperatures will likely reach or exceed 70° in much of the region.

At the same time, a storm could bring 1”-3” of snow to Detroit on tomorrow into Wednesday. Detroit’s most recent measurable snow on or after April 20 occurred on May 10, 2020 when 0.5” of snow fell. 

Detroit’s daily snowfall records are:

April 20: 1.2”, 1947

April 21: 0.3”, 1978

hey Detroit's 0.5 last year was around the same time we had snow last May!  same system?

 

[LibertyBell]

1 hour ago, bluewave said:

It’s actually been a warmer than average April so far with numerous 70° days. But the cool downs after each warm up have created a cooler perception.  We make another run on 70° before the sharp cold front on Wednesday. This is when strong to locally severe convection will be possible across the region. Then another sharp cool down into the 30s with a freeze just N and W of NYC. This is followed by another rebound in temperatures with a coastal storm possible on Sunday. Longer range may come down to the typhoon interaction with the mid and higher latitude pattern. The OP GFS and EPS are hinting that the SE Ridge will try to flex near the end of the month. So that may be the next chance to reach 80° if the models don’t shift before then.
 

KEWR   GFSX MOS GUIDANCE   4/19/2021  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 MON  19| TUE 20| WED 21| THU 22| FRI 23| SAT 24| SUN 25| MON 26 CLIMO
 X/N  67| 50  71| 52  58| 33  56| 39  65| 47  69| 51  66| 51  70 45 64
 

SE ridge builds near end of April?

Chris will that coastal over the weekend also cause snow in the mountains?

[donsutherland1]

3 minutes ago, LibertyBell said:

hey Detroit's 0.5 last year was around the same time we had snow last May!  same system?

 

Detroit had a trace of snow from the system that impacted us and then 0.5" from a follow-up system.

[donsutherland1]

31 minutes ago, LibertyBell said:

even more surprising would be accumulating snow for both KC and St Louis!

Kansas City will likely see its first measurable snowfall after April 15 since May 2, 2013 when 0.5" fell. The last time a post-April 15 storm brought more than 1" of snow to Kansas City was April 20, 1992 when 2.7" fell.

I doubt St. Louis will have measurable snow. The last time St. Louis had measurable snow after April 15 was April 18, 1997 when 0.1" was recorded. The climate database shows May 6, 1998, but that is wrong, as the minimum temperature was 62 degrees. That was hail, not snow. It should have been flagged by quality control given the minimum temperature, alone.

There is only one case where both Kansas City and St. Louis received measurable snow on the same day after April 15: April 24, 1910 when Kansas City picked up 0.1" and St. Louis received 1.1".

[FPizz]

1 hour ago, LibertyBell said:

ah okay, it doesn't feel that warm because we have had no 80s (and barely any 70s and low 70s at that) and I've had the heat on every day.

The min thing always taints the average, it never feels that warm unless the high temp is 70+ on a consistent basis.

 

The diurnal range has been large pretty often this month.  So we have needed the heat on at night, but then maybe can open a window by 3 pm.  

[bluewave]

1 hour ago, LibertyBell said:

ah okay, it doesn't feel that warm because we have had no 80s (and barely any 70s and low 70s at that) and I've had the heat on every day.

The min thing always taints the average, it never feels that warm unless the high temp is 70+ on a consistent basis.

 

+1 to +2 is the new normal. So we need a +3 to +4 monthly departure to seem warm. That’s what we got back in March with a top 5 monthly high temperature reaching 84° at Newark. So this would translate into 90°+ in April to have a similar warm feel. 

 

[LibertyBell]

3 minutes ago, bluewave said:

+1 to +2 is the new normal. So we need a +3 to +4 monthly departure to seem warm. That’s what we got back in March with a top 5 monthly high temperature reaching 84° at Newark. So this would translate into 90°+ in April to have a similar warm feel. 

 

this makes me think we should keep climate normals for 10 years instead of 30, to account for the quicker changes we are now having

 

[LibertyBell]

1 hour ago, donsutherland1 said:

Detroit had a trace of snow from the system that impacted us and then 0.5" from a follow-up system.

I take it we didn't get anything from the follow up and it went to our west?  I was in NE PA and it was such a wintry system, woke up on Saturday morning, the 10th, with temps in the teens and wind chills near 0 and snow squalls all day long which were accumulating when it snowed hard during the day!  May 10th!

I dont know if you have any records for this Don, but do you have any numbers for the May 9-10, 1977 snowstorm in the Mount Pocono and Lake Harmony area (both are above 2,000 ft.)

 

[donsutherland1]

1 hour ago, LibertyBell said:

ah okay, it doesn't feel that warm because we have had no 80s (and barely any 70s and low 70s at that) and I've had the heat on every day.

The min thing always taints the average, it never feels that warm unless the high temp is 70+ on a consistent basis.

 

Today is one day where the high temperature will likely beat the guidance. The MOS shows 65 as a high for Central Park. At 11 am, it was already 63 there.

[LibertyBell]

Just now, donsutherland1 said:

Today is one day where the high temperature will likely beat the guidance. The MOS shows 65 as a high for Central Park. At 11 am, it was already 63 there.

Maybe JFK will reach 70 also!

 

[donsutherland1]

Just now, LibertyBell said:

I take it we didn't get anything from the follow up and it went to our west?  I was in NE PA and it was such a wintry system, woke up on Saturday morning, the 10th, with temps in the teens and wind chills near 0 and snow squalls all day long which were accumulating when it snowed hard during the day!  May 10th!

Central New York State received some snow from the follow-up system, but it passed to our north and west.

[donsutherland1]

6 minutes ago, LibertyBell said:

Maybe JFK will reach 70 also!

 

Probably not. JFK should reach the mid-60s. NYC will probably top out at 66-67. Clouds will increase this afternoon.

[donsutherland1]

12 minutes ago, LibertyBell said:

I take it we didn't get anything from the follow up and it went to our west?  I was in NE PA and it was such a wintry system, woke up on Saturday morning, the 10th, with temps in the teens and wind chills near 0 and snow squalls all day long which were accumulating when it snowed hard during the day!  May 10th!

I dont know if you have any records for this Don, but do you have any numbers for the May 9-10, 1977 snowstorm in the Mount Pocono and Lake Harmony area (both are above 2,000 ft.)

 

Mount Pocono picked up 8.2”. I have no data from Lake Harmony.

[bluewave]

18 minutes ago, LibertyBell said:

this makes me think we should keep climate normals for 10 years instead of 30, to account for the quicker changes we are now having

 

This will be the first time that we have 15 and 30 year climate normals with an update. So the annual average snowfall will be very high if we get a 15 year average. So it will be interesting to see all the new normals when they are released soon.

https://www.ncei.noaa.gov/news/Upcoming-NOAA-2020-Climate-Normals

Calculating the New Climate Normals

Palecki emphasized that NOAA’s Normals are rather complicated sets of calculations, not just simple averages. These calculations fill in missing data using surrounding weather stations and ensure that daily Normals match monthly Normals. They also remedy discrepancies that might arise when stations change locations.

In this next round of Climate Normals, new things will be added—including several small changes to how NCEI calculates them.

“Our main methodologies have not changed since the last Normals cycle,” Palecki said. “But minor improvements have been made in how we round numbers, calculate percentiles, count the numbers of days exceeding thresholds, and format output.”

Also, for the first time, this updated batch of Normals will include 15-year Normals for those needing a climatology representing a period closer to today. NOAA will also release high spatial resolution monthly Normals data for the conterminous U.S., as well as develop new tools and methods to access the data

 

[LibertyBell]

7 minutes ago, bluewave said:

This will be the first time that we have 15 and 30 year climate normals with an update. So the annual average snowfall will be very high if we get a 15 year average. So it will be interesting to see all the new normals when they are released soon.

https://www.ncei.noaa.gov/news/Upcoming-NOAA-2020-Climate-Normals

Calculating the New Climate Normals

Palecki emphasized that NOAA’s Normals are rather complicated sets of calculations, not just simple averages. These calculations fill in missing data using surrounding weather stations and ensure that daily Normals match monthly Normals. They also remedy discrepancies that might arise when stations change locations.

In this next round of Climate Normals, new things will be added—including several small changes to how NCEI calculates them.

“Our main methodologies have not changed since the last Normals cycle,” Palecki said. “But minor improvements have been made in how we round numbers, calculate percentiles, count the numbers of days exceeding thresholds, and format output.”

Also, for the first time, this updated batch of Normals will include 15-year Normals for those needing a climatology representing a period closer to today. NOAA will also release high spatial resolution monthly Normals data for the conterminous U.S., as well as develop new tools and methods to access the data

 

Another idea I had was maybe we could do a weighed average?  Keep the 30 year average but weigh the last 10 years twice as much as the 20 years prior.....that would give priority to the changing climate.

 

[LibertyBell]

12 minutes ago, donsutherland1 said:

Mount Pocono picked up 8.2”. I have no data from Lake Harmony.

Thanks Don, do you have data from Mt Pocono for May 9-10, 2020 also, to compare to 1977 on the same dates?  I think it was around 2" but not sure.

 

[FPizz]

Already 100% clouds here in N CNJ.   Forecast was 67, currently 64 is the high.  Maybe those NE of here with more sun can touch 70

[donsutherland1]

37 minutes ago, LibertyBell said:

Thanks Don, do you have data from Mt Pocono for May 9-10, 2020 also, to compare to 1977 on the same dates?  I think it was around 2" but not sure.

 

MPO no longer records the daily snowfall. There is also no local storm report for that event. 

[LibertyBell]

1 hour ago, donsutherland1 said:

MPO no longer records the daily snowfall. There is also no local storm report for that event. 

and nothing for anywhere in the Poconos, like Lake Harmony or Albrightsville?

 

[LibertyBell]

2 hours ago, FPizz said:

Already 100% clouds here in N CNJ.   Forecast was 67, currently 64 is the high.  Maybe those NE of here with more sun can touch 70

been pretty cloudy the last 2 days

[uncle W]

I hope the real numbers are not the so called smoothed...its doesn't add up to the real averages...

[psv88]

2 hours ago, FPizz said:

Already 100% clouds here in N CNJ.   Forecast was 67, currently 64 is the high.  Maybe those NE of here with more sun can touch 70

Forecast high was 64, hit 67

[psv88]

14 hours ago, TriPol said:

Last Summer wasn't that hot. When was the last time we hit 100+?

Sure it was. 

100 degrees has nothing to do if its a hot summer. 100 degree reading tells you how dry the air was. Even tropical areas dont hit 100 because it takes an incredible amount of energy to heat humid air to 100 degrees, and it usually rains. 

And i do believe LGA and EWR hit 100 recently. Either way, 100 degrees happens when you have a dry westerly flow. Lately we have had the SE ridge and bermuda high kicking up a more SW flow, so we bake mid 90s with dews over 75. Again, hitting 100 has no bearing at all on how "hot" a summer is. 100/60 feels much cooler than 91/77. 

[Cfa]

Heat Indices have been surpassing 100 quite a bit the past few summers.

Anyway, these clouds are a PITA. 70 would’ve been a guarantee if it had stayed sunny for a bit longer, high was 67.

[donsutherland1]

46 minutes ago, LibertyBell said:

and nothing for anywhere in the Poconos, like Lake Harmony or Albrightsville?

 

Unfortunately, not. The lack of such measurements leaves gaps in the climate record. 

[bluewave]

On 4/17/2021 at 4:12 PM, Gravity Wave said:

Lapse rates are usually the missing ingredient for big severe outbreaks in this region, I remember the October 2018 PA tornado outbreak where they played a key role. If it hadn't been for the low instability (it was October after all) it would have been a memorable event.

https://en.wikipedia.org/wiki/Tornadoes_of_2018#October_2

The latest forecast soundings  have some of the steepest surface to 500 mb lapse rates that we have seen in April. Looks like the potential for a severe squall line Wednesday afternoon,. Pretty impressive severe signal for April.