March 2021

[donsutherland1]

Morning thoughts...

A blizzard is currently bringing heavy snow and high winds to parts of the Rockies. So far, Denver has picked up 11.1” of snow. Areas around Cheyenne had picked up 8” of snow just before midnight MST.

A strong cold front will cross the region today. Overall, it will be partly sunny and increasingly windy. Winds could gust past 50 mph in some areas. There could be an isolated sprinkle.  Temperatures will likely top out mainly in the upper 40s and lower 50s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 53°

Newark: 55°

Philadelphia: 58°

Tomorrow will be sunny and unseasonably cold. Much of the region will see low temperatures in the lower 20s. Outside the major cities, some teens are possible. The March 16-19 period could still offer a period of opportunity for a light snow event in parts of the region.

Out west, the major to perhaps historic snowstorm will rage into this evening. Snow will diminish at night or early tomorrow. Denver will likely experience a storm total 12”-18” snowfall. Cheyenne remains on track to pick up a storm total 20”-30” of snow. 

Cheyenne’s March Snowfall Records:

Daily: 15.9”, March 18, 2003; 2-Day: 17.2”, March 17-18, 2003; 3-Day: 18.9”, March 5-7, 1990

Cheyenne’s All-Time Snowfall Records:

Daily: 19.8”, November 20, 1979; 2-Day: 25.2”, November 20-21, 1979; 3-Day: 25.6”, November 19-21, 1979

[bluewave]

Unusually dry 50/50 low suppression pattern right into mid-March. Boston set a new record for the least amount of clouds during the first two weeks of March. Dewpoints and relative humidity have been falling below model guidance. So it allowed temperatures to warm above guidance and set daily high temperature records. Another Arctic front will cross the area this afternoon. Winds may gust past 50 mph with steep lapse rates right up to 750 mb and temperatures in the 50s. Low temperatures Monday morning temperatures may drop to the low 20s in places like Newark. This would be 55° colder than just a few days ago. Dewpoints look to drop below  0 on Monday. If we can reach to near -10 or lower, then it would be close to the record for mid-March.

 

[CIK62]

50mph Gusts may  remain offshore except near Sandy Hook area and east coast of LI.

[donsutherland1]

Back on March 5 0z, the EPS ensembles were indicating that there would be a pattern similar to that of March 9-15, 2020.
https://www.americanwx.com/bb/topic/54600-march-2021/?do=findComment&comment=5954517March 9-12, 2021 saw what turned out to be an even more amplified version of the 2020 pattern, as the Arctic Oscillation (AO) soared to a preliminary March record of +5.656.

 

As a result, the March 9-12, 2021 timeframe was even warmer than the March 9-15, 2020 period.

Boston:
Average High: 2020: 56.9°; 2021: 62.0°
Average Low: 2020: 37.3°; 38.3°
Mean: 2020: 47.0°; 2021: 50.1°
Highest: 2020: 72°; 2021: 74°

New York City:
Average High: 2020: 60.7°; 2021: 64.3°
Average Low: 2020: 45.0°; 2021: 44.8°
Mean: 2020: 52.9°; 2021: 54.5°
Highest: 2020: 72°; 71°

Philadelphia:
Average High: 2020: 63.6°; 2021: 70.3°
Average Low: 2020: 43.1°; 2021: 42.0°
Mean: 2020: 53.4°; 2021: 56.1°
Highest: 2020: 74°; 2021: 74°

In sum, this experience suggests the insight hemispheric patterns can provide. Synoptic details, including the placement of features and magnitude of amplification, determine the details of how things turn out.

[crossbowftw3]

The level of concern I hold for Wednesday's severe event down south is escalating. This wide warm sector could be accompanied by favorable shear, LRs, moderate forcing, and very favorable surface track.

This is a warm sector you should be seeing in April or May, not March. This is getting increasingly worrying.

[weathermedic]

Winds starting to pick up as of 1pm. Gusting to low-mid 30 mph range at the area airports.

Dew points mainly in the mid to upper teens.

[bluewave]

1 hour ago, crossbowftw3 said:

The level of concern I hold for Wednesday's severe event down south is escalating. This wide warm sector could be accompanied by favorable shear, LRs, moderate forcing, and very favorable surface track.

This is a warm sector you should be seeing in April or May, not March. This is getting increasingly worrying.

 

 

[nyrangers1022]

Got dark and very windy. Squall coming in, temp 44

[bluewave]

Gusting close to 60 mph now in Newburgh.

 

[Rtd208]

Very large brush fire w/structures involved in Lakewood, Ocean County. Fire is at a 3rd alarm level. Parkway shutdown.

[nyrangers1022]

3 minutes ago, bluewave said:

Gusting close to 60 mph now in Newburgh.

 

I believe it.  I'm a few miles away from the airport

[bluewave]

52 minutes ago, nyrangers1022 said:

I believe it.  I'm a few miles away from the airport

Gusting close to 50 mph now on Long Island.

Jones Beach      N/A     50 N/A N/A NW36G48    
Matinecock Pt    N/A     48 N/A N/A W41G49      

[Cfa]

I can see virga to the north. Wind starting to roar overhead, still fairly calm at the surface, very weird sensation.

55 and mostly sunny. Last rain was 13 days ago.

[forkyfork]

1 hour ago, Rtd208 said:

Very large brush fire w/structures involved in Lakewood, Ocean County. Fire is at a 3rd alarm level. Parkway shutdown.

small one now in the meadowlands 

[Rtd208]

4 minutes ago, forkyfork said:

small one now in the meadowlands 

It probably won't stay small for long with these weather conditions. 

[forkyfork]

it's definitely growing 

[gravitylover]

This wind is the real deal. Power was out for a while, it's back up now but keeps flickering. I was out and coming home was going over some big branches, one was big enough I needed to raise the (air) suspension on my Range Rover to get over it without high centering. 

[donsutherland1]

There was a sprinkle in New Rochelle, NY a short time ago.

[doncat]

13 hours ago, LibertyBell said:

Do you have any low humidity records for your station?

 

I keep records for just about everything, but not humidity lol...I believe the lowest my station has gotten is around 13%.

[Rjay]

Umm 49 degrees with light snow

[Rjay]

Gotten sleet near 50 before but never snow. It was definitely snow lol.  

[bluewave]

61 mph peak gust on Long Island.

 

[donsutherland1]

31 minutes ago, Rjay said:

Gotten sleet near 50 before but never snow. It was definitely snow lol.  

It can happen. I saw it once when I was west of Trois Rivières in Canada.

[rclab]

36 minutes ago, Rjay said:

Gotten sleet near 50 before but never snow. It was definitely snow lol.  

Rjay you just made Anthony’s day, As always ....

[LoboLeader1]

Currently 39 here, had a wind gust of 52 mph earlier.

[bluewave]

1 hour ago, doncat said:

I keep records for just about everything, but not humidity lol...I believe the lowest my station has gotten is around 13%.

I think that 3-30-07 may be the record lowest relative humidity.

LGA

1:51 PM

63 F

2 F

9 %

EWR

5:51 PM

68 F

-5 F

5 %

JFK

7:51 PM

64 F

0 F

8 %

[NorthShoreWx]

2 hours ago, Rjay said:

Gotten sleet near 50 before but never snow. It was definitely snow lol.  

Had a 5 minute burst of snow accompanied by strong wind gusts about 2 hours ago.  Temp was 48 when it started.  Down to 38 now and still strong wind gusts.  No wind damage so far this time; I'm out of cupolas.

[doncat]

43 minutes ago, bluewave said:

I think that 3-30-07 may be the record lowest relative humidity.

LGA

1:51 PM

63 F

2 F

9 %

EWR

5:51 PM

68 F

-5 F

5 %

JFK

7:51 PM

64 F

0 F

8 %

Yeah did have a 10% reading on the Vantage on that day.

[donsutherland1]

Tomorrow will be the coldest day of the week and possibly the coldest day until at least late next fall. Temperatures will tumble into the lower and middle 20s from Philadelphia to New York City and into the teens in some areas outside of those cities. This cold shot following the recent warmth is not unusual.

Since 1990, 73% of cases that saw a high temperature of 70° or above during March 1-15 were followed by a low temperature of 32° or below during the following two weeks. 54% of such cases saw a low temperature below 30° during the following two weeks and 27% saw the temperature fall below 25°. The mean lowest temperature during the following two weeks was 29°. In addition, the March 16-19 period could offer a period of opportunity for a light snow event in parts of the region.

Next weekend could mark the start of a new warming trend. Since 1950, nearly 60% of days two weeks after the AO reached +3.000 or above in the March 1-15 period were warmer than when the AO reached +3.000 or above. The AO reached +3.000 on March 10. The mean increase was 2.8°. This suggests that it is more likely than not that the closing week of March could see a return to warmer conditions.

Out west, a major to historic blizzard will continue into late tonight or early tomorrow. Cheyenne will likely set its all-time storm total snowfall record.

Cheyenne's All-Time Snowfall Records:

Daily: 19.8”, November 20, 1979; 2-Day: 25.2”, November 20-21, 1979; 3-Day: 25.6”, November 19-21, 1979  

The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.7°C for the week centered around March 3. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.43°C and the ENSO Region 3.4 anomaly has averaged -0.87°C. La Niña conditions will likely prevail at least through most of March. Afterward, neutral-cool ENSO conditions will likely develop as the spring progresses.

The SOI was -2.44 today. The SOI had recently been negative for 10 consecutive days. That development could be an early indication that what has been a fairly stable La Niña regime throughout the winter could be moving closer to its end stages.

The preliminary Arctic Oscillation (AO) figure was +4.329 today.

On March 13 the MJO data was unavailable.

The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 28.1" snow.

Winters that saw December receive 10" or more snow, less than 10" in January, and then 10" or more in February in New York City, saw measurable snowfall in March or April in 83% of cases. Winter 2009-2010 was the exception where only a trace of snow was recorded. This group of winters saw 6" or more snow during the March-April period in 50% of the cases. All said, it is more likely than not that there will be measurable snowfall after February.  

Based on sensitivity analysis applied to the latest guidance, there is an implied 62% probability that New York City will have a warmer than normal March. March will likely finish with a mean temperature near 43.2° (0.7° above normal).

 

[donsutherland1]

Cheyenne has seen 22.2” snow today. The 22.2” daily snowfall beats the old daily record of 19.8”, which was set on November 20, 1979. The 30.3” storm total surpasses the 25.6” that fell during November 19-21, 1979 to become Cheyenne’s biggest snowstorm on record.