April 2021

[LibertyBell]

16 hours ago, bluewave said:

Looks like another low dewpoint and low relative humidity special today. Dewpoints are forecast to drop to near 0 with temperatures getting back above 50°. We make a run on 60° tomorrow and get back into the 60s on Monday. So it’s tough to maintain the record cold of the last few days very long.

 

KEWR   GFS MOS GUIDANCE    4/03/2021  0600 UTC                      
 DT /APR   3      /APR   4                /APR   5             /     
 HR   12 15 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 00 06 
 X/N              55          38          58          40       65    
 TMP  36 44 52 55 51 46 42 40 44 49 55 56 53 48 44 42 46 56 62 58 50 
 DPT   9  3  3  5 11 17 21 25 29 31 31 29 29 30 29 28 29 28 27 30 32 

the blue skies were gorgeous today

[CIK62]

The next 8 days are averaging 52degs.,(46/58)., or about +2.0 or more.

Continues dry till the 10th.

GFS Ens. has no 70's from Boston to D.C  for the next 15 days.       Keeps us dry till the 10th., and Boston till the 15th.,w/o a 60-degree day there.      52* by 11am.

46*(52%RH) here at 6am., thin overcast.      47* at 7am.      50* by 10am.     52* by Noon.      58* by 4pm.           Reached 60* about 5:30pm.        

[bluewave]

4 hours ago, LibertyBell said:

what kind of temps are we talking about with these storms?

Mid April was mentioned....could we be talking about something like April 15, 2007, aka the Tax Day noreaster?

 

Looks like we are headed for a pattern when the warmest days top out in the 60s. Some days that get more onshore flow and clouds may only make it to the 50s.  The blocking has corrected further south in the most recent model runs. So the lows get forced by well to our south. The NW to NE flow prevents us from making a run on 80s like late March  for a while. Our next chance at any significant rains will have to wait for the block to weaken a bit. Funny how we are seeing a spring version of the winter south based blocking pattern.
 

KEWR   GFSX MOS GUIDANCE   4/04/2021  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 SUN  04| MON 05| TUE 06| WED 07| THU 08| FRI 09| SAT 10| SUN 11 CLIMO
 X/N  61| 43  67| 43  66| 44  65| 48  61| 47  59| 46  56| 42  59 40 59

 

New run blocking pressing further south

Old run more low pressure near the Northeast

 

 

[Rtd208]

37 minutes ago, bluewave said:

Looks like we are headed for a pattern when the warmest days top out in the 60s. Some days that get more onshore flow and clouds may only make it to the 50s.  The blocking has corrected further south in the most recent model runs. So the lows get forced by well to our south. The NW to NE flow prevents us from making a run on 80s like late March  for a while. Our next chance at any significant rains will have to wait for the block to weaken a bit. Funny how we are seeing a spring version of the winter south based blocking pattern.
 

KEWR   GFSX MOS GUIDANCE   4/04/2021  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 SUN  04| MON 05| TUE 06| WED 07| THU 08| FRI 09| SAT 10| SUN 11 CLIMO
 X/N  61| 43  67| 43  66| 44  65| 48  61| 47  59| 46  56| 42  59 40 59

 

New run blocking pressing further south

Old run more low pressure near the Northeast

 

 

If it is going to be cool I would rather have heavy rain and wind versus light mist and dreary. But unless the blocking eases we may have just that. We'll see.

[bluewave]

6 minutes ago, Rtd208 said:

If it is going to be cool I would rather have heavy rain and wind versus light mist and dreary. But unless the blocking eases we may have just that. We'll see.

The south based blocking has been the real deal since early December. We can see how it has resulted in a drier pattern for New England.   We’ll probably have to wait for it to weaken a bit to get more significant rain chances again here.  But the rains eventually end up arriving even if they get pushed back a little from earlier forecasts.

 

[donsutherland1]

Morning thoughts...

Early morning clouds will give way to sunshine. The afternoon will be mostly sunny and mild. High temperatures will likely reach the lower and middle 60s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 63°

Newark: 64°

Philadelphia: 67°

Tomorrow will be mostly sunny and mild.

Out West, there is a chance that the temperature could make a run at 100° at Phoenix for the first time this year today. Should the temperature reach the century mark, that would be the 3rd earliest such temperature on record for Phoenix. 

[bluewave]

6 hours ago, LibertyBell said:

why is it that these months were much warmer in the 90s and early 00s?

April 2002 is my benchmark for spring warmth.

It’s one of the quirks of our warming climate. The average first 80° day has moved one month earlier up at Newark from April 28th in 1970 to March 31st in 2021. But the average first 90° day has remained nearly unchanged from May 19th in 1970 to May 21st in 2020. So record early 90°+ heat like April 2002 remains rare. The fall is reversed. Later last 90° day  while the last 80° day is mostly unchanged.
 

 

[donsutherland1]

6 hours ago, LibertyBell said:

Three days in 2003 really stands out, almost as much as what happened in 1982.

People often mention the extreme cold in April 1982 but forget that April 2003 was also pretty extreme.  Is 3 straight days the record for April, Don?  Looks like we could've also done it in 1982 but barely missed with the day in between?

 

The record is 5 consecutive days. The record was set from April 2 through April 6, 1881.

[donsutherland1]

6 hours ago, LibertyBell said:

wow thats a very late freeze for Savannah- latest ever? and Jacksonville down in the mid 30s, there should be a frost advisory for North Florida!

 

The latest freeze at Charleston occurred on April 20, 1983 when the temperature fell to 31°.

[uncle W]

the cold spell in April 1975 was significant...1943 and 1950 had very cold Aprils...April rarely averages below 50.0 in NYC these days...2018 and 2003 are the only Aprils that averaged below 50.0 since 1975...before that 1967 despite record highs at the beginning of the month...

[LibertyBell]

1 hour ago, donsutherland1 said:

The latest freeze at Charleston occurred on April 20, 1983 when the temperature fell to 31°.

Same day when JFK had its latest accumulating snow- 1.5"?

 

[LibertyBell]

1 hour ago, bluewave said:

It’s one of the quirks of our warming climate. The average first 80° day has moved one month earlier up at Newark from April 28th in 1970 to March 31st in 2021. But the average first 90° day has remained nearly unchanged from May 19th in 1970 to May 21st in 2020. So record early 90°+ heat like April 2002 remains rare. The fall is reversed. Later last 90° day  while the last 80° day is mostly unchanged.
 

 

wow that is weird- any reason why this might be happening, maybe more precip is causing this?

 

[donsutherland1]

1 hour ago, LibertyBell said:

Same day when JFK had its latest accumulating snow- 1.5"?

 

A day later. JFK’s latest measurable snowfall occurred on April 19, 1983.

[A Moonlit Sky]

On 4/2/2021 at 11:30 PM, donsutherland1 said:

Basically, air flows toward the area of low pressure. As that happens, air rises leading to condensation and then precipitation.

Here’s a more detailed summary:

https://scied.ucar.edu/learning-zone/how-weather-works/highs-and-lows-air-pressure

Thank you, for this. I did not know that the air from high and low pressures spun differently. That explains why lows off the coast in spring cause cooler temps.

[HailMan06]

3 hours ago, A Moonlit Sky said:

Thank you, for this. I did not know that the air from high and low pressures spun differently. That explains why lows off the coast in spring cause cooler temps.

Look up Coriolis effect

[donsutherland1]

Clouds gave way to sunshine and the temperature rose into the 60s in much of the region this afternoon. Tomorrow will be fair and continued mild.

Meanwhile, near record and record warm temperatures prevailed from the Southwest to the Northern Plains. Daily record high temperatures included:

Bismarck: 83° (old record: 82°, 1921)
Casper: 74° (tied record set in 1943)
Cheyenne: 75° (old record: 72°, 1889)
Colorado Springs, CO: 79° (old record: 77°, 1959 and 1967)
Denver: 80° (old record: 76°, 1959 and 1967)
Huron, SD: 83° (tied record set in 1929)
La Crosse, WI: 80° (tied record set in 1910 and tied in 1929)
Las Vegas: 91° (tied record set in 1943 and tied in 1959 and 1961)
Phoenix: 98° (tied record set in 1961)
Rochester, MN: 80° (old record: 77°, 1929 and 1942)
Tucson: 96° (old record: 94°, 1943)

Phoenix has had 29 days since 1896 when the temperature fell below 40° in April. The last such date occurred on April 11, 1979 when the mercury fell to 39°. Phoenix has never had an April freeze.

At Tucson, there have been 18 days on which the temperature fell to or below freezing in April since 1895. The last such date was April 4, 1945 when the temperature dipped to a monthly record low of 27°.

Tomorrow will be another very warm day from the Southwest to the Northern Plains States. Afterward, the excessive warmth will shift into northeastern Canada where some record high temperatures will be possible from Wednesday through Saturday.

In the northern Middle Atlantic and southern New England areas, temperatures will likely top out in the 60s through Thursday. Afterward, it will become somewhat cooler. Then, temperatures could be confined mainly to the 50s in much of the region. Based on the latest guidance, no significant precipitation is likely into the weekend.

Historic experience following a warm to very warm March suggests a probability that is skewed toward a warmer than normal April. That warmer scenario remains the base case despite the current strong cold shot.

The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -0.6°C for the week centered around March 24. 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 -0.67°C. La Niña conditions will likely give way to neutral-cool ENSO conditions as the spring progresses.

The SOI was +4.47 today.

The preliminary Arctic Oscillation (AO) figure was +0.454 today.

On April 2 the MJO was in Phase 5 at an amplitude of 1.477 (RMM). The April 1-adjusted amplitude was 1.397 (RMM).

 

[MJO812]

[sferic]

12 hours ago, donsutherland1 said:

A day later. JFK’s latest measurable snowfall occurred on April 19, 1983.

There was an actual winter storm warning posted for NYC on that date

[LibertyBell]

6 hours ago, MJO812 said:

NYC edged out Boston

 

[LibertyBell]

5 hours ago, sferic said:

There was an actual winter storm warning posted for NYC on that date

6 inches for parts of Long Island.

How is it Central Park didn't record anything?

 

[CIK62]

The next 8 days are averaging 54degs (47/61), or +3.0.

EURO/CMC are bone dry for the next 10 days now and the GFS is holding on to the rain for the 10th.

Next T convulsion is pushed to the 13th(80's?), then quickly back to 60 in a day or two.

48*(47%RH) here at 6am.      51* by 9am.     58* by Noon.         65*(25%RH) by 3pm.        67*(23%RH) at 4pm.          69*(23%RH) at 5pm.        60* by 10pm.

[bluewave]

The warm spots may make a run on 70° today as these dry and windy downslope days often beat guidance.

 

KEWR   GFS MOS GUIDANCE    4/05/2021  0000 UTC                      
 DT /APR   5            /APR   6                /APR   7          /  
 HR   06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 18 00 
 X/N                    68          44          66          46    67 
 TMP  50 47 49 58 64 67 61 55 49 46 50 57 62 64 60 55 50 48 51 64 61 
 DPT  27 27 28 27 26 25 27 29 29 28 29 25 22 23 26 30 32 33 35 34 37 
 CLD  CL CL FW FW FW CL SC BK CL CL CL CL FW FW FW FW CL CL FW SC BK 
 WDR  31 27 31 32 31 30 30 31 31 28 31 32 31 32 32 33 30 36 35 34 11 
 WSP  07 07 13 15 17 18 16 12 06 05 08 11 13 10 09 04 03 02 04 06 06 

 

[donsutherland1]

Morning thoughts...

It will be mostly 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): 67°

Newark: 68°

Philadelphia: 69°

Tomorrow will be mostly sunny and continued warm.

[LibertyBell]

1 hour ago, bluewave said:

The warm spots may make a run on 70° today as these dry and windy downslope days often beat guidance.

 

KEWR   GFS MOS GUIDANCE    4/05/2021  0000 UTC                      
 DT /APR   5            /APR   6                /APR   7          /  
 HR   06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 18 00 
 X/N                    68          44          66          46    67 
 TMP  50 47 49 58 64 67 61 55 49 46 50 57 62 64 60 55 50 48 51 64 61 
 DPT  27 27 28 27 26 25 27 29 29 28 29 25 22 23 26 30 32 33 35 34 37 
 CLD  CL CL FW FW FW CL SC BK CL CL CL CL FW FW FW FW CL CL FW SC BK 
 WDR  31 27 31 32 31 30 30 31 31 28 31 32 31 32 32 33 30 36 35 34 11 
 WSP  07 07 13 15 17 18 16 12 06 05 08 11 13 10 09 04 03 02 04 06 06 

 

Maybe JFK will hit 70?  These are my favorite kinds of days.

 

[donsutherland1]

3 hours ago, LibertyBell said:

6 inches for parts of Long Island.

How is it Central Park didn't record anything?

 

Central Park picked up 0.8”. 

[sferic]

3 hours ago, LibertyBell said:

Maybe JFK will hit 70?  These are my favorite kinds of days.

 

I love the back door cold fronts myself

[Santa Claus]

not a cloud in the sky and more good weather coming up.  good baseball weather.  the Yankees are playing baseball's greatest team, the Baltimore Orioles, in the Bronx the next three days.  the Orioles are heavily favorited to sweep but anything can happen.

[FPizz]

On 4/4/2021 at 2:46 AM, LibertyBell said:

wow thats a very late freeze for Savannah- latest ever? and Jacksonville down in the mid 30s, there should be a frost advisory for North Florida!

 

Funny thing, I was in the Jacksonville area on vacation.  Those were some cool mornings!  It felt like here, haha.  I did manage to have 2 80+ days down there though last week.  

[Rtd208]

Really nice day out there.

Current temp is 69 here.

[Intensewind002]

67F with a dewpoint of only 21 right now imby