February 2021

[Brian5671]

12 minutes ago, LibertyBell said:

when I see so much blue on the map thats what I immediately think of.  It's best to be just inside the outer edge of the blue or, since we're right in the middle of winter, in the white area between the blue and red anomalies

 

you want some SE ridge-gives a boundary for storms to run.   I always see people get excited for bitter cold-yeah it's extreme weather but like others said-cold/dry/boring

[Cfa]

Dallas-Fort Worth will be flirting with lower single digits next week, I’m glad it’s them and not us.

[donsutherland1]

A light snowfall is possible late tonight into tomorrow. Accumulations should generally reach 1" or less in New York City's nearby northern and western suburbs, 1"-3" in New York City, and 2"-4" across parts of central New Jersey and southeastern Pennsylvania, including Philadelphia.

A blend of the guidance suggests the following snowfall amounts: New York City: 1.8"; Newark: 2.1"; and, Philadelphia: 3.4"

As a result, New York City's Central Park will record its first month with 20" or more snow since 27.9" fell in January 2016 and its first February with 20" or more snow since 2014 when 29.0" was measured. Philadelphia will likely see its first month with 10" or more snow since March 2018 when 15.2" was recorded and its first February with 10" or more snow since 2014 when 22.4" fell.

Another weak system will pass even farther south on Friday.

Today saw more near record and record cold in parts of western Canada and also Montana. Select low temperatures:

Cut Bank, MT: -38° (old record: -33°, 1939) ***Coldest day since February 8, 1994***
Dease Lake, BC: -40° (old record: -35°, 2017)
Havre, MT: -33°
Medicine Hat, AB: -27° (-17°, 2014)
Prince George, BC: -35° (old record: -32°, 1948)
Thompson, MB: -44°

That frigid air mass will slowly advance eastward and possibly reach the Middle Atlantic and southern New England regions around mid-month. There is some uncertainty as to whether this air mass will move directly into the region sending temperatures into the single digits even in New York City or merely pass nearby delivering a glancing blow with single-digit cold avoiding New York City but affecting areas outside of New York City and Newark. The probability of the latter outcome has continued to increase. It is more likely than not that the latter scenario will play out.

The Arctic Oscillation (AO) is now severely negative and at its lowest levels in nearly eight years. It is forecast to rise sharply toward mid-month. A dramatic increase in the AO has sometimes coincided with storminess. Therefore, the February 14-24 period might offer a window of opportunity for a meaningful storm. Details about possible storm tracks or precipitation types are premature at this point.

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 February 3. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -1.00°C. La Niña conditions will likely prevail at least through meteorological winter.

The SOI was +20.03 today.

Today, the preliminary Arctic Oscillation (AO) figure was -5.152 today. That is the lowest AO figure since the AO was -5.240 on March 22, 2013. The last time the AO was at -5.000 or below in February was February 14, 2010 when the AO was -5.132.

On February 9 the MJO was in Phase 7 at an amplitude of 2.246 (RMM). The February 8-adjusted amplitude was 2.143.

Based on the latest guidance, no significant stratospheric warming event is likely through the middle of the third week of February.  

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 22.0" snow.

Based on sensitivity analysis applied to the latest guidance, there is an implied 82% probability that New York City will have a colder than normal February. February will likely finish with a mean temperature near 32.3° (3.0° below normal).

 

[bluewave]

19 minutes ago, Cfa said:

Dallas-Fort Worth will be flirting with lower single digits next week, I’m glad it’s them and not us.

Yeah, those areas will be closer to the path of the current record breaking high pressure when it drops south.

https://forecast.weather.gov/product.php?site=NWS&issuedby=FWD&product=AFD&format=CI&version=1&glossary=0

The freezer door will then be propped open on Sunday as mid level
ridging amplifies over the Northwest U.S. and our polar low over
Southern Canada pivots eastward allowing a chunk of arctic air to
spread southward through the Plains. A 1050 mb high will surge
southward behind a strong cold front but ahead of a compact
shortwave ejecting out of the southwest U.S. This will set the
stage for some exceptionally cold air to spread into North Texas
over the latter half of the weekend into early next week. We`re
becoming increasingly concerned for a prolonged cold spell with
actual air temperatures falling into the single digits to near 0
across parts of the region by Monday. While the GFS is currently
the coldest guidance, other global guidance and ensemble members
indicate 850 mb temps falling into the -12 to -17 degree range
which would be in the coldest 10% of temperatures in our observed
sounding data. In addition, a pool of moisture will reside across
much of East Texas and should quickly surge northwestward into the
region as strong forcing overspreads North Texas late Sunday into
Monday. With column temperatures as cold as currently forecast,
widespread moderate to heavy snow would be expected to develop as
the shortwave spreads across the Southern Plains. The current
forecast will reflect these trends with all snow by late Sunday
night and continuing into Monday. While it`s a little early to pin
down exact accumulations, as of now, it appears that widespread
snowfall amounts of 2 to 4 inches will be possible over a large
area of the region. Column temperatures would be cold enough to
support higher snowfall ratios than we typically see which could
result in significantly heaftier snow totals. North winds 15 to 25
mph could also result in significant reductions to visibility
during the snow. This will be a fast moving system, but definitely
has the potential for significant impacts to travel and
infrastructure across the region. Extremely cold weather will
continue into the middle of next week.

It should be stressed that this bout of extreme cold may have
significant impact to infrastructure over the latter part of the
weekend into early next week. Exposed pipes are likely to burst in
the prolonged cold. Preparations should be made now to protect
exposed pipes or other infrastructure sensitive to the cold. Plans
should be made for pets and people.

 

[wdrag]

Will update all threads by 8A today...  one at a time. I think the GFSV16 stopped running at 00z/11 90 hrs w unknown rts.  My first take for the NYC group.

We'll see what the 7A NYC ob has (T at midnight climo).  I think a bit more snow late 13-14 with a change to ice or rain later Valentines Day for NYC. I like a bit of snow accumulation first 6-12 hours of the overall light event. Meanwhile nw NJ newd  and the I84 corridor 1-4" looks good to me with maybe a touch of sleet?  Advisory event for some of the forum just because of ice risk. 

15?? modeling???  could be messy in the afternoon but reserving this to say

late 15-early 17... i like a colder solution than modeled...not soo much warming at 850MB and more snow, so I think NYC will see some snow acc but ice could eventually get involved NJ/LI. Modeling is pretty cold at the surface. This will be a moderate event. Advisory event or possibly even a warning event for some of the subforum. 

18-19 (thread stops at 18) but this event is complex with predominant ice (ice to rain LI) but may end as snow everywhere?  So far no sign of a closed low slowing things any further so have to go with what we see.  NAEFS turns interestingly cold in the 1000-500 thickness to wrap this event up on the 19th. 

Will parse all this out in the threads by 8A.  Later, Walt 521A/11

[SnoSki14]

Early thoughts are that we take a break from wintry weather after the 16th system however we could see an ice/snow to rain solution for the 18/19 as the low level cold will be tough to scour out. 

But mostly from the 17-23/24 it looks unfavorable for wintry weather. Beyond that it's possible the blocking returns while the SE ridge diminishes (MJO collapses into circle or goes low amplitude 6-8). 

If that's the case there could be more wintry opportunities late Feb into March. 

[CIK62]

The next 8 days are averaging 23degs.(16/29), or -11.0.

GFS back with 23" total snow over the next 15 days.     16th/17th and the 25th. will do it.

29*(87%RH), light snow fell overnight.   28* at 7am.       32* by 10am.    34* by Noon.       32* by 2pm.      34* again at 3pm.

 

[bluewave]

Only the 16 year since 1950 that NYC went 40 days without reaching 50°.

 

Number of Consecutive Days Max Temperature < 50 
for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Rank	Run Length	Ending Date
1	77	1969-03-15
2	65	1977-02-10
3	63	2015-03-08
4	54	1971-02-11
5	50	1981-02-01
6	47	2004-02-20
-	47	1985-02-18
-	47	1970-01-28
7	46	1968-03-07
8	44	2007-03-01
-	44	1996-01-17
-	44	1978-03-11
-	44	1956-02-07
9	43	2001-01-29
10	42	2011-02-13
11	40	2021-02-11

[donsutherland1]

Morning thoughts...

Light to moderate snow was still falling over parts of central and southern New Jersey and into southeastern Pennsylvania this morning. Philadelphia had picked up 3.1” snow. In Nassau County, Elmont (1 WNW) had received 4.2”. There will likely be some breaks in the clouds and sunshine for a time, especially from New York City northward. Temperatures will likely top out in the lower and middle 30s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 35°

Newark: 34°

Philadelphia: 35°

Tomorrow will be partly cloudy. Another system could bring some light snow to parts of the region on Sunday.

[bluewave]

Looks like one of the greatest AO rises from -5 that we have seen coming up. 
 

 

 

[EastonSN+]

9 minutes ago, bluewave said:

Looks like one of the greatest AO rises from -5 that we have seen coming up. 
 

 

 

Wouldn't that signify the end of the blocking period? Or is the blocking merely shifting from the AO to NAO domain?

[bluewave]

16 minutes ago, EastonSN+ said:

Wouldn't that signify the end of the blocking period? Or is the blocking merely shifting from the AO to NAO domain?

The strongest blocking of the whole winter was within the last few days. Looks like it gets weaker and becomes more east based going forward. You can see the shift on the long range models.

 

[Intensewind002]

After last night's snow event, I'm now at 25.8" of snow for February, my seasonal total is exactly 33"

[etudiant]

Whatever happened to the record cold NYC was supposed to experience this weekend?

[bluewave]

44 minutes ago, etudiant said:

Whatever happened to the record cold NYC was supposed to experience this weekend?

The models lost the single digits lows for NYC a while ago. So the coldest temperatures will dump into the Plains. Probably related to the very strong MJO 7 pattern. But NYC still has a shot to drop below 20°.

New run

Old run

 

 

[MJO812]

37 minutes ago, bluewave said:

The models lost the single digits lows for NYC a while ago. So the coldest temperatures will dump into the Plains. Probably related to the very strong MJO 7 pattern. But NYC still has a shot to drop below 20°.

New run

Old run

 

 

Snowing with temps in the teens as depicted by the gfs next week would be amazing.

[MJO812]

Weenies dream

[Brian5671]

8 minutes ago, MJO812 said:

Weenies dream

heard that was run out of JB's basement....

[donsutherland1]

A weak system brought a light snowfall to much of the region from New York City's nearby northern suburbs southward. Another weak system will pass too far to the south tonight into tomorrow to bring any snowfall to most of the region.

With today's 1.3" snowfall, New York City's Central Park's monthly snowfall has increased to 21.2" making February 2021 its first first month with 20" or more snow since 27.9" fell in January 2016 and its first February with 20" or more snow since 2014 when 29.0" was measured. 5/17 (29%) of New York City's February 20" cases have occurred since 2000. Philadelphia picked up 3.1" snowfall bringing its February total to 10.1". That makes this month its first month with 10" or more snow since March 2018 when 15.2" was recorded and its first February with 10" or more snow since 2014 when 22.4" fell.

Frigid air will continue to slowly advance eastward into this weekend. However, this bitterly cold air mass will likely deliver only a glancing blow with single-digit cold avoiding New York City but affecting some areas outside of New York City and Newark. Its largest impact could be the possibility of a period of freezing rain on Sunday from Philadelphia to New York City and their suburbs. Any snowfall accumulations in Philadelphia, Newark, and New York City will likely be light.

The Arctic Oscillation (AO) is now severely negative and at its lowest levels in nearly eight years. It is forecast to rise sharply toward mid-month. The latest guidance suggests that the AO could attain positive values for the first time since December 25, 2020 when the AO was +0.226. Whether this development will mark the end of the prolonged period of blocking that has prevailed throughout winter 2020-21 remains to be seen.

A dramatic increase in the AO has sometimes coincided with storminess. Therefore, the February 14-24 period might offer a window of opportunity for a meaningful storm. Details about possible storm tracks or precipitation types are premature at this point. That window of opportunity could extend through the end of February should blocking persist or return.

Since 1950, there were 11 cases during the January 16-February 28 timeframe that saw the AO rise at least 3 sigma from a minimum value of -4.000 or below within a 7-day period. Four cases saw a major snowstorm in parts of the Middle Atlantic or New England regions within 3 weeks of the AO's reaching its minimum value. The dates of the AO's minimum value for those four cases are January 25, 1958, January 19, 1969, February 15, 1969, and January 16, 2016.

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 February 3. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -1.00°C. La Niña conditions will likely prevail at least through meteorological winter.

The SOI was +11.34 today.

Today, the preliminary Arctic Oscillation (AO) figure was -5.314 today. That is the lowest AO figure since March 21, 2013 when the AO was -5.399.

On February 10 the MJO was in Phase 7 at an amplitude of 2.075 (RMM). The February 9-adjusted amplitude was 2.248.

Based on the latest guidance, no significant stratospheric warming event is likely through the end of the third week of February.  

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 23.3" snow.

Based on sensitivity analysis applied to the latest guidance, there is an implied 88% probability that New York City will have a colder than normal February. February will likely finish with a mean temperature near 32.1° (3.2° below normal).

 

[CIK62]

Another confused GFS 18Z run.       Enough LE for 50"+ at just an 8:1 ratio.

[bluewave]

1 hour ago, MJO812 said:

Weenies dream

 

Those old version GFS maps will become collectors items when the v16 goes operational on St Patrick’s Day. Still wish I kept a few old DGEX forecast maps.

 

[eduggs]

The trof axis for the upcoming series of storms looks relatively far west - looks like an ice or rain type setup. If we're lucky it will trend snowier. But we might have run out of our luck for this winter.

[MJO812]

2 minutes ago, eduggs said:

The trof axis for the upcoming series of storms looks relatively far west - looks like an ice or rain type setup. If we're lucky it will trend snowier. But we might have run out of our luck for this winter.

Its only Feb 11 

[nycwinter]

5 minutes ago, eduggs said:

The trof axis for the upcoming series of storms looks relatively far west - looks like an ice or rain type setup. If we're lucky it will trend snowier. But we might have run out of our luck for this winter.

you cant be serious..

[eduggs]

2 minutes ago, MJO812 said:

Its only Feb 11 

We can't count on consistent threats through mid March. There's no guarantee we get any more snow at all. Of course we could also be in for a big snowy finish. Either way, we probably have 4 or 5 more weeks of legit wintry potential. 

[MJO812]

3 minutes ago, eduggs said:

We can't count on consistent threats through mid March. There's no guarantee we get any more snow at all. Of course we could also be in for a big snowy finish. Either way, we probably have 4 or 5 more weeks of legit wintry potential. 

I always wait until the first week of April to declare winter over.

[eduggs]

Just now, nycwinter said:

you cant be serious..

I am. A lot of people have it in their heads that lots of snow is coming. And it might be. But this is not a slam dunk "pattern." To me it looks icy, then rainy, and then very uncertain towards the long range.

[SnoSki14]

8 minutes ago, eduggs said:

The trof axis for the upcoming series of storms looks relatively far west - looks like an ice or rain type setup. If we're lucky it will trend snowier. But we might have run out of our luck for this winter.

It's a major ice storm setup. Very dangerous imo.

[HVSnowLover]

Just now, eduggs said:

I am. A lot of people have it in their heads that lots of snow is coming. And it might be. But this is not a slam dunk "pattern." To me it looks icy, then rainy, and then very uncertain towards the long range.

Yea I have it in my head that a lot of ice is coming, more then we may know what to do with as I am not used to significant icing events.   

[eduggs]

Just now, MJO812 said:

I always wait until the first week of April to declare winter over.

We tracked May snow just last year. But realistically, after Mid March, widespread snowfall along the coastal plain is very uncommon. We have about a month of a window left. And for pack lovers, we have about 2 weeks before the sun will quickly decimate almost anything outside the high country.