April 2019 General Discussions & Observations Thread

[Cfa]

Currently 68 after a high of 73, the warmest of the year so far.

[bluewave]

Euro showing no let up in this wet pattern. Has storm systems racing across the Northeast every several days. 

 

[doncat]

Did manage 79 degrees briefly before seabreeze….. now down to 68.

[donsutherland1]

The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.8°C for the week centered around April 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.15°C and the ENSO Region 3.4 anomaly has averaged +0.95°C. Conditions consistent with El Niño should persist into the first week in May in Region 3.4.

The SOI was +0.36 today.

Today's preliminary value of the Arctic Oscillation (AO) was +1.622.

The implied probability of a warmer than normal April is currently 98%. There is also an implied 72% probability that April 2019 will wind up among the 10 warmest April cases on record and 52% probability that it will wind up among the 5 warmest April cases on record.

The 5 Warmest April Mean Temperatures were as follows:

1. 57.9°, 2010
2. 56.9°, 1941
3. 56.2°, 1981
4. 56.1°, 1921, 2002
5. 55.9°, 1969　

On April 22, the MJO was in Phase 2 at an amplitude of 2.080 (RMM). The amplitude sharply higher than the April 21-adjusted figure of 1.313.

Since 1974, there were four cases when the MJO reached an amplitude of 1.750 or above during Phase 2 during the April 20-30 period. The mean May 1-10 temperature was 58.8° vs. the 1981-2018 average of 60.2°. 75% of those cases were cooler than the 1981-2018 average. However, during May cases when the ENSO Region 3.4 anomaly was +0.50°C or above for the month, the May 1-10 temperature averaged 60.8°. Therefore, it is likely that the first 10 days of May will probably wind up with a mean temperature of 59.2°-61.2°.

[CIK62]

Really warmed in last two hours from 57* to 66* at 11pm.

[Rtd208]

13 hours ago, bluewave said:

Euro showing no let up in this wet pattern. Has storm systems racing across the Northeast every several days. 

 

Looks like the NAM/GFS are becoming wetter for Friday/Saturday.

[dWave]

6 hours ago, CIK62 said:

Really warmed in last two hours from 57* to 66* at 11pm.

Yeah was a warm night. 65*

[CIK62]

The remainder of April averaging 57degs., or just Normal.

Month to date is +3.9[55.8]. 

April should end at +3.0[56.1].    This is a tie for Fourth Place.   I favored lower T's since we seem to be going backwards as we limp to the finish line, so nearby 3rd. Place still possible.

[bluewave]

Today looks like another day that we could beat high temperature guidance around the area. The warm downslope flow is already several degrees higher than model forecasts. JFK and Wantagh are 65 degrees at 8am. One of those warm offshore flow spring days when the South Shore can reach 70 or higher.

 

[JerseyWx]

1 hour ago, bluewave said:

Today looks like another day that we could beat high temperature guidance around the area. The warm downslope flow is already several degrees higher than model forecasts. JFK and Wantagh are 65 degrees at 8am. One of those warm offshore flow spring days when the South Shore can reach 70 or higher.

 

Shaping up to be a beautiful and dry day.  Dew points in the 30's here.

[doncat]

1 hour ago, bluewave said:

Today looks like another day that we could beat high temperature guidance around the area. The warm downslope flow is already several degrees higher than model forecasts. JFK and Wantagh are 65 degrees at 8am. One of those warm offshore flow spring days when the South Shore can reach 70 or higher.

 

My station's  warmest April was back in 2010...a couple more 70° days and I may beat it.

[Brian5671]

68 and sunny here-everything is really growing and starting to leaf out with the warm temps following all the rains of the last week.

[tek1972]

Finally spring temperatures
I'm enjoying

Sent from my SM-N960U using Tapatalk

[Brian5671]

6 minutes ago, tek1972 said:

Finally spring temperatures
I'm enjoying

Sent from my SM-N960U using Tapatalk
 

Feels great out there.

[bluewave]

3 hours ago, doncat said:

My station's  warmest April was back in 2010...a couple more 70° days and I may beat it.

The April 55.8 average in NYC is currently the 6th warmest. 

	2010	57.9	0
	2017	57.2	0
	1941	56.8	0
	2002	56.1	0
	1981	56.1	0
	1921	56.1	0
	1969	55.9	0
	2019	55.8	7

[Dan76]

1 hour ago, Brian5671 said:

68 and sunny here-everything is really growing and starting to leaf out with the warm temps following all the rains of the last week.

Cut the grass monday first time this year.

[TriPol]

Any chance of severe weather this upcoming week?

[NycStormChaser]

57 minutes ago, TriPol said:

Any chance of severe weather this upcoming week?

Friday is looking a lot better. A nice squall line moves through. 

[Rtd208]

Current temp is 70 here. A very nice day out there.

[dWave]

Beautiful day..San Diego type day

[purduewx80]

2 hours ago, NycStormChaser said:

Friday is looking a lot better. A nice squall line moves through. 

should be an interesting day in at least parts of the region. there is enough elevated instability for thunderstorms in the city, but it's not yet clear if we get any surface-based CAPE nearby. some models are picking up on a more phased look at 500mb friday - that would certainly do it w/ the dynamics at play and a redeveloping coastal low passing across the city or long island. sounds pretty much like a continuation of our winter pattern.

[LongBeachSurfFreak]

Today was about as perfect of a day as you can get to work outside. Nice spread out rains have been great for plants as well.

[donsutherland1]

Fair weather will hold for another day in the Middle Atlantic and New England areas. However, a system will likely bring showers and perhaps some thundershowers Friday into Saturday. At present, most of the New York City area should see 0.25"-0.75" rain with some locally higher amounts.

The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.8°C for the week centered around April 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.15°C and the ENSO Region 3.4 anomaly has averaged +0.95°C. Conditions consistent with El Niño should persist into the first week in May in Region 3.4.

The SOI was -9.30 today.

Today's preliminary value of the Arctic Oscillation (AO) was +1.056.

The implied probability of a warmer than normal April is currently 99%. There is also an implied 74% probability that April 2019 will wind up among the 10 warmest April cases on record and 52% probability that it will wind up among the 5 warmest April cases on record.

The 5 Warmest April Mean Temperatures were as follows:

1. 57.9°, 2010
2. 56.9°, 1941
3. 56.2°, 1981
4. 56.1°, 1921, 2002
5. 55.9°, 1969

On April 23, the MJO was in Phase 2 at an amplitude of 2.470 (RMM). The amplitude was higher than the April 22-adjusted figure of 2.079. The amplitude is the highest on record for Phase 2 during the April 20-30 period.

Since 1974, there were four cases when the MJO reached an amplitude of 1.750 or above during Phase 2 during the April 20-30 period. The mean May 1-10 temperature was 58.8° vs. the 1981-2018 average of 60.2°. 75% of those cases were cooler than the 1981-2018 average. However, during May cases when the ENSO Region 3.4 anomaly was +0.50°C or above for the month, the May 1-10 temperature averaged 60.8°. Therefore, it is likely that the first 10 days of May will probably wind up with a mean temperature of 59.2°-61.2°.

Finally, the 12z ECMWF suggests the possibility of some snow Saturday night or Sunday in Chicago. To date, Chicago has seen 47.0" snow for the 2018-19 season, which is 10.7" above normal.

[CIK62]

Last 6 days of April averaging 55degs., or about 2degs. BN!!!.

Month to date is +4.0[56.1].     Looks like April drops to 6th. Place with a finish now of +2.8[55.8].

I warned days ago the GFS/CMC were cooling for the end of the month.   This is what statistically you should get as you get near the end, while being near a record, or Top 10-----not like the idiocy of Dec. 2015.

51* here at 6am.

[Brian5671]

2 hours ago, CIK62 said:

Last 6 days of April averaging 55degs., or about 2degs. BN!!!.

Month to date is +4.0[56.1].     Looks like April drops to 6th. Place with a finish now of +2.8[55.8].

I warned days ago the GFS/CMC were cooling for the end of the month.   This is what statistically you should get as you get near the end, while being near a record, or Top 10-----not like the idiocy of Dec. 2015.

51* here at 6am.

we're due for some cool, that's for sure.  But of course, given the winter pattern, it may come in muted as we close in....

[donsutherland1]

4 hours ago, CIK62 said:

Last 6 days of April averaging 55degs., or about 2degs. BN!!!.

Month to date is +4.0[56.1].     Looks like April drops to 6th. Place with a finish now of +2.8[55.8].

I warned days ago the GFS/CMC were cooling for the end of the month.   This is what statistically you should get as you get near the end, while being near a record, or Top 10-----not like the idiocy of Dec. 2015.

51* here at 6am.

I agree.

Such a cool end to the month would bring temperatures more in line with historic experience following the kind of strongly negative AO values that were seen earlier this month. Since 1950, there had been 6 cases where the AO dropped to -2.500 or below during April 1-10. The mean April 16-30 temperature for those cases was 56.3° with a standard deviation of 2.3°.

For a time, the projected figure on the guidance exceeded 60°. With last night's guidance (through 6z), the estimate is now 57.6°.

That figure might be skewed a little by the 38° low temperature shown on the 0z GFS MOS. Most of the other guidance is somewhat warmer than that.

Such an outcome would be an uncommon event. The last time New York City (Central Park) had a temperature of 38° or below on or after April 29 was May 1, 1978 when the temperature fell to 38°.

[Gravity Wave]

40 minutes ago, donsutherland1 said:

Such an outcome would be an uncommon event. The last time New York City (Central Park) had a temperature of 38° or below on or after April 29 was May 1, 1978 when the temperature fell to 38°.

That's honestly quite surprising. I remember a lot of May mornings in Allentown growing up where the temps were below 40. I guess that's the UHI doing its thing.

[bluewave]

18 hours ago, purduewx80 said:

should be an interesting day in at least parts of the region. there is enough elevated instability for thunderstorms in the city, but it's not yet clear if we get any surface-based CAPE nearby. some models are picking up on a more phased look at 500mb friday - that would certainly do it w/ the dynamics at play and a redeveloping coastal low passing across the city or long island. sounds pretty much like a continuation of our winter pattern.

NAM has a pocket of surface based CAPE over PA/NJ with the squall later Friday. That’s where the NAM has the highest severe potential.

[purduewx80]

2 hours ago, bluewave said:

NAM has a pocket of surface based CAPE over PA/NJ with the squall later Friday. That’s where the NAM has the highest severe potential.

It's a shame lapse rates aren't better. The warm front will probably get hung up before the triple point/coastal low passes through in the evening, but I still think there will be ample forcing/instability for elevated storms region-wide. Some of the hi-res today is showing multiple rounds of convection tomorrow.

[donsutherland1]

3 hours ago, Gravity Wave said:

That's honestly quite surprising. I remember a lot of May mornings in Allentown growing up where the temps were below 40. I guess that's the UHI doing its thing.

UHI plays a major role. Outside NYC, such cold mornings are far more frequent. The 12z MEX MOS ticked up a degree to 39°.