March 2018 Discussions & Observations Thread

[Enigma]

For the day 10 storm, the teleconnections strongly point towards a major east coast storm.

[NJwx85]

8 minutes ago, Enigma said:

For the day 10 storm, the teleconnections strongly point towards a major east coast storm.

As they did with the storm coming up this weekend.

[MJO812]

52 minutes ago, NJwx85 said:

As they did with the storm coming up this weekend.

Not really

PNA will be rising

This storm still hasn't happened so we don't know what the outcome will be.

[MJO812]

Euro control has over 20 inches for the NYC area with storm 2.

[SnoSki14]

1 hour ago, NJwx85 said:

As they did with the storm coming up this weekend.

Actually they didn't, models initially showed this coming storm as a strong cutter because the blocking hadn't settled in yet and snow was never on the table with this one. 

They now show a coastal, which should tuck in closer to the close given the powerful -NAO block setting in. We're not going to escape the coming pattern without a strong system.

[LongBeachSurfFreak]

12 minutes ago, SnoSki14 said:

Actually they didn't, models initially showed this coming storm as a strong cutter because the blocking hadn't settled in yet and snow was never on the table with this one. 

They now show a coastal, which should tuck in closer to the close given the powerful -NAO block setting in. We're not going to escape the coming pattern without a strong system.

Wow for once we actually agree. Let’s just focus on the signal right now and not the finer details. Storm one has to play out first. I believe storm one ends up following the seasonal trend and ends up more tucked in. Hence my belief that the highest areas of the interior are in for a blue bomb. Storm two is still light years away. The signal is strong for now.

[Rjay]

Use this thread for pattern discussion and obs.  

[Paragon]

On 2/26/2018 at 12:52 PM, snowman19 said:

Here we go again with the theme of events getting less impressive as we draw closer, this has been reoccurring over and over since November. I guess we’re going to continue this into March. If we are going to see anymore snow, it needs to happen by 3/9 in my opinion. The pattern will be shifting in the north PAC and I think we are torching by St. Patrick’s Day weekend. 

It's fine if we're torching by then though.  I'd push that back by a few days though, because usually we have our last accumulating snowfall somewhere in the March 20-22 period (right near the equinox) so after that it can torch all it wants to   I hope we return to the hot summers of the early 2010s too.

We normally get our last 6"+ storm before 3/15 but we can still pretty regularly get snowfalls of a few inches up to 3/20-22.  Not including the once a decade April snowstorms of course.

[donsutherland1]

My March idea (following a sensational February bust):

March will begin with a severe AO-/NAO- blocking regime. Such early March blocking has often resulted in a colder than normal month, sometimes with much above average snowfall. Some cases have also featured big “near miss” storms. 1962 and 2001 provide such examples.

Nuances in the 500 mb pattern can make a large difference in the overall monthly outcomes. Although the mean 500 mb height anomalies during the first week of March will closely resemble those from March 1958, there is a subtle but potentially significant difference. The above normal 500 mb height anomalies will likely extend southward from eastern Canada to near the U.S. Gulf Coast this time around. In 1958, that area extended only to the U.S.-Canada border. This should translate into a warmer first week of the month than was the case in 1958 even if ongoing warming were not underway.

Since 1950, March has been warming about 0.6°F per decade in New York City. 1950 was selected, as the City already had a mature urban footprint at that time. Since 1980, the observed warming has increased to approximately 1.0°F per decade.

As the block retrogrades, the March 7-20 period could feature a mean trough undercutting the block. This is the type of pattern that could feature an above normal probability of a large snowfall should a storm undercut the block. While Arctic air is not likely to be involved, there could be sufficiently cold air to allow for at least a heavy wet snow event from such a storm. The most-favored MJO Phases would be 4-5 (46% of events that brought 4” or more snow to at least two of the following cities during the March 7-20 period: Boston, New York, Philadelphia, and Washington, DC). 

After around March 20, the 500 mb pattern could grow increasingly unfavorable for snow events, first in the New York City Metro Area and the adjacent New Jersey-Long Island-coastal Connecticut suburbs and, later, the more distant northern and western suburbs.

Overall, a weighted composite with 1958 and 1962 (2 times the weight of 1958) seems to make reasonable sense for the first 2-3 weeks of the month given the blocking episode and forecast evolution of the blocking through mid-month. The more expansive area of above normal 500 mb height anomalies should be factored in, as well.

Based on these premised, my guess is that March will have a monthly mean temperature of 43.5° +/- 0.5° (somewhat above normal) in New York City. Monthly snowfall will likely wind up in the 2”-6” range (normal is 3.9”). Far northern and western suburbs will likely see double those amounts. The snowfall range is a low confidence idea, as a single large storm could result in much more snowfall than what is shown.

Finally, the opening of the month (March 2-3) will likely see a significant nor’easter impact the northern Mid-Atlantic and New England areas. As colder air is drawn into the deepening storm’s circulation, rain will likely change to a period of accumulating snow well to the north and west of New York City. The City and nearby suburbs could see the rain mix with or change to snow before the precipitation ends. A crippling snowfall is possible across central New York State, including the Finger Lakes Region. Coastal areas could experience flooding during high tide and beach erosion. High winds could also bring down limbs and possibly uproot trees, especially on eastern Long Island and the Connecticut shore.

[CIK62]

Are you sure of those increases in the averages for Feb/Mar.?

I have a 1968 NYC Weather Almanac whose 30 year norms would be from 1930-59, with a midpoint of 1945, or at least 6 decades beyond the current midpoint  of say 2005.  It shows just a 2 degree increase for both these months since then.

This is an increase of  0.033deg/year.

[EastonSN+]

2 hours ago, donsutherland1 said:

My March idea (following a sensational February bust):

March will begin with a severe AO-/NAO- blocking regime. Such early March blocking has often resulted in a colder than normal month, sometimes with much above average snowfall. Some cases have also featured big “near miss” storms. 1962 and 2001 provide such examples.

Nuances in the 500 mb pattern can make a large difference in the overall monthly outcomes. Although the mean 500 mb height anomalies during the first week of March will closely resemble those from March 1958, there is a subtle but potentially significant difference. The above normal 500 mb height anomalies will likely extend southward from eastern Canada to near the U.S. Gulf Coast this time around. In 1958, that area extended only to the U.S.-Canada border. This should translate into a warmer first week of the month than was the case in 1958 even if ongoing warming were not underway.

Since 1950, March has been warming about 0.6°F per decade in New York City. 1950 was selected, as the City already had a mature urban footprint at that time. Since 1980, the observed warming has increased to approximately 1.0°F per decade.

As the block retrogrades, the March 7-20 period could feature a mean trough undercutting the block. This is the type of pattern that could feature an above normal probability of a large snowfall should a storm undercut the block. While Arctic air is not likely to be involved, there could be sufficiently cold air to allow for at least a heavy wet snow event from such a storm. The most-favored MJO Phases would be 4-5 (46% of events that brought 4” or more snow to at least two of the following cities during the March 7-20 period: Boston, New York, Philadelphia, and Washington, DC). 

After around March 20, the 500 mb pattern could grow increasingly unfavorable for snow events, first in the New York City Metro Area and the adjacent New Jersey-Long Island-coastal Connecticut suburbs and, later, the more distant northern and western suburbs.

Overall, a weighted composite with 1958 and 1962 (2 times the weight of 1958) seems to make reasonable sense for the first 2-3 weeks of the month given the blocking episode and forecast evolution of the blocking through mid-month. The more expansive area of above normal 500 mb height anomalies should be factored in, as well.

Based on these premised, my guess is that March will have a monthly mean temperature of 43.5° +/- 0.5° (somewhat above normal) in New York City. Monthly snowfall will likely wind up in the 2”-6” range (normal is 3.9”). Far northern and western suburbs will likely see double those amounts. The snowfall range is a low confidence idea, as a single large storm could result in much more snowfall than what is shown.

Finally, the opening of the month (March 2-3) will likely see a significant nor’easter impact the northern Mid-Atlantic and New England areas. As colder air is drawn into the deepening storm’s circulation, rain will likely change to a period of accumulating snow well to the north and west of New York City. The City and nearby suburbs could see the rain mix with or change to snow before the precipitation ends. A crippling snowfall is possible across central New York State, including the Finger Lakes Region. Coastal areas could experience flooding during high tide and beach erosion. High winds could also bring down limbs and possibly uproot trees, especially on eastern Long Island and the Connecticut shore.

That is Don.

The EPO rises rapidly around the 9th. Before that time the AO NAO and EPO are negative with favorable MJO phases. The PNA is LESS negative.

I hope we get this forum to seasonal average during this window.

[CIK62]

First 8 days of Mar. averaging about 43degs., or 5 or 6 degs. AN.  Mar. 7,8 need to be watched.

[donsutherland1]

February finished in fitting springlike style with the mercury reaching 61° in Central Park, the 6th 60° or above temperature in February. Only 1976 had more such days with 8. As a result, February finished with a mean temperature of 42.0°, which surpassed the record of 41.6° set just last year. Records in New York City go back to 1869.

Boston, where records go back to 1872, tied 1925 for the warmest February on record. In that city, the monthly average temperature was 38.1°.

With the balmy breezes of February now in the past, March will be coming in like a lion. A strong nor’easter will likely bring heavy rains, strong winds, and coastal flooding to the Jersey Shore, Long Island, New York City Metro Area, and coastal Connecticut. The rain could end as a period of snow in and around New York City. A minor accumulation can’t be ruled out there, especially on grassy surfaces. With only modest changes, even an inch or two of wet snow could be possible in the City, so one will still have to watch the evolution of the nor’easter very carefully. Interior sections including Warren and Sussex Counties in New Jersey and Delaware, Orange, Sullivan, and Ulster Counties in New York currently have the best chance to pick up a moderate or greater (4” or more) snowfall. 

New York City’s Average Temperature Through:

3/5 41.0°-45.8°
3/10 39.1°-44.5°

Per aggressive sensitivity analysis, the estimated probability of an above normal monthly anomaly: 52%

[tmagan]

15 minutes ago, donsutherland1 said:

February finished in fitting springlike style with the mercury reaching 61° in Central Park, the 6th 60° or above temperature in February. Only 1976 had more such days with 8. As a result, February finished with a mean temperature of 42.0°, which surpassed the record of 41.6° set just last year. Records in New York City go back to 1869.

Boston, where records go back to 1872, tied 1925 for the warmest February on record. In that city, the monthly average temperature was 38.1°.

With the balmy breezes of February now in the past, March will be coming in like a lion. A strong nor’easter will likely bring heavy rains, strong winds, and coastal flooding to the Jersey Shore, Long Island, New York City Metro Area, and coastal Connecticut. The rain could end as a period of snow in and around New York City. A minor accumulation can’t be ruled out there, especially on grassy surfaces. With only modest changes, even an inch or two of wet snow could be possible in the City, so one will still have to watch the evolution of the nor’easter very carefully. Interior sections including Warren and Sussex Counties in New Jersey and Delaware, Orange, Sullivan, and Ulster Counties in New York currently have the best chance to pick up a moderate or greater (4” or more) snowfall. 

New York City’s Average Temperature Through:

3/5 41.0°-45.8°
3/10 39.1°-44.5°

Per aggressive sensitivity analysis, the estimated probability of an above normal monthly anomaly: 52%

CPC has a 40% chance of above normal temperatures in March. I think it is pretty much a lock of an above normal mean March temperatures.

[donsutherland1]

1 minute ago, tmagan said:

CPC has a 40% chance of above normal temperatures in March. I think it is pretty much a lock of an above normal mean March temperatures.

I expect that NYC and nearby areas will finish about 1° or a little more above normal (about a 43.5° mean temperature).

[tmagan]

4 minutes ago, donsutherland1 said:

I expect that NYC and nearby areas will finish about 1° or a little more above normal (about a 43.5° mean temperature).

Also, I'd look for a top ten wettest March in Central Park.

[the_other_guy]

Amazing temp difference between southern Westcheter and city this morning.

13 degrees at one point.

What is causing this? Seems like a copout to constantly say UHI.

Places on LI have the same temp difference with city, so it’s not a coastal thing.

Has the city developed so much in recent decades that they have fundamentally altered normal low temperatures on clear nights? 

[EastonSN+]

I am going to be stuck at 2.5 inches below average aren't I?

Well, will be only the 5th below average snowfall winter this century!

As for the teleconnections, blocking remains in place till about the 20th. However, the EPO goes strongly positive on the 9th on both GEFS and EPS. Our chance to score till the 9th

[nesussxwx]

5 minutes ago, EastonSN+ said:

I am going to be stuck at 2.5 inches below average aren't I?

Well, will be only the 5th below average snowfall winter this century!

As for the teleconnections, blocking remains in place till about the 20th. However, the EPO goes strongly positive on the 9th on both GEFS and EPS. Our chance to score till the 9th

century or decade? Lol.

 

[EastonSN+]

6 minutes ago, nesussxwx said:

century or decade? Lol.

 

Century. The only below average snowfall winters:

2001 2002

2006 2007

2007 2008

2011 2012

Probably this year by 2.5 inches.

[Dan76]

Only 18yrs check back in in another 50

[donsutherland1]

5 hours ago, tmagan said:

Also, I'd look for a top ten wettest March in Central Park.

With the upcoming storm, NYC will take a big step in that direction. For context, the 10th wettest March was March 1913 when 6.47" precipitation fell. The record is 10.69", which was set in 2010.

[LongBeachSurfFreak]

7 hours ago, tmagan said:

CPC has a 40% chance of above normal temperatures in March. I think it is pretty much a lock of an above normal mean March temperatures.

The issue is the polar vortex split. All the cold air dumped in Europe and Eurasia. So there is very like cold for us to tap into. 

Next weeks storm has a little more cold to work with so that ones still I play. Had we had cold air on this side of the globe we would have been talking about one of the all time greats

[jm1220]

2 hours ago, LongBeachSurfFreak said:

The issue is the polar vortex split. All the cold air dumped in Europe and Eurasia. So there is very like cold for us to tap into. 

Next weeks storm has a little more cold to work with so that ones still I play. Had we had cold air on this side of the globe we would have been talking about one of the all time greats

Last March’s shaft job would’ve been one of the greats too if it tracked 75 miles east. Goes to show how much needs to go right here for a big snow event. 

[Rtd208]

Picked up 0.47" of rain for the day. 

[DRVTS]

Pouring already.....not rain.  Accumulating 1/4 inch so far

[DRVTS]

Wwa my a__.      going to get a generator

1 inch already. Pouring paste

[DRVTS]

 Now that we are now casting, can anyone comment on how much snow putnam county may get? I am considering closing my offices for the day based on the fact that it’s pouring snow so early.  I was planning on  having accumulating snow in the afternoonbut not  so early. 

[North and West]

Down to 36 above MMU. Rain.


.

[donsutherland1]

A powerful nor’easter will bring heavy rains, strong winds, and coastal flooding to the Jersey Shore, Long Island, New York City Metro Area, and coastal Connecticut today into tonight. As of 6 am, precipitation totals included: Bridgeport: 1.00”; Danbury: 0.85”; Islip: 1.57”; New Haven: 0.53”; New York City: 1.21”; Newark: 1.26”; Poughkeepsie: 0.73” (where the rain had turned to snow); Westhampton: 1.10”; and, White Plains: 1.29”.   

The rain could end as a period of snow in and around New York City. A coating to 2” is possible there (1”-3” in Newark), especially on grassy surfaces. Interior sections including Warren and Sussex Counties in New Jersey and Delaware, Orange, Sullivan, and Ulster Counties in New York will generally pick up 6”-12” snow with some locally higher amounts. Dutchess County could see 4”-8” with some locally higher amounts.

It should be noted that there remains a risk that New York City could get into a band of very heavy wet snow. The 0z ECMWF and 6z NAM (3 km and 12 km) show that scenario. Under such a scenario, surface temperatures could fall to 33°-34° during the most intense snowfall and 4” or more snow could fall. That remains a less likely scenario than the evolution of an event where the rain ends with a period of moderate wet snow as the bands of heaviest snow miss the City coupled with somewhat higher surface temperatures. 

New York City’s Average Temperature Through:

3/1 52.0° (14.0° above normal)
3/5 41.0°-44.6° (3/1 estimate: 41.0°-45.8°)
3/10 39.6°-44.4° (3/1 estimate: 39.1°-44.5°)

Per aggressive sensitivity analysis, the estimated probability of an above normal monthly anomaly: 53% (3/1 estimate: 52%)