Jump to content
  • Member Statistics

    17,588
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

January 2017 Discussion & Observations


dmillz25

Recommended Posts

  • Replies 1.6k
  • Created
  • Last Reply

i'm just looking forward to that nice band moving east,it's looking healthy and expanding into our area.might be our last little shot of snow before rain for the next couple of days.currently 24/17f..i had a low of 18 here in the bronx earlier..let's see how this overrunning band performs before the switchover,which most likely won't happen as quick with feisty cold air around. 

Link to comment
Share on other sites

Last evening, I noted the relationship between the PDO and PNA. During the January 1950-2016 period, PDO- values coincided with PNA- values 62% of the time and PDO+ values coincided with PNA+ values 73% of the time. Since December 23, the PNA has been negative, although it rose to -0.232 on January 9 (preliminary value).

The ensembles are continuing to show the return of a PNA+ in the medium-term. What is new is that a number of ensemble members are now suggesting that the PNA+ could be sustained. It’s still a little early to be confident in such an outcome, but the relationship between the PDO and the continuing fade of the recent La Niña event argue for an increased prospect of PNA ridging (PNA+) as the winter continues to progress.

Borrowing from Dr. Jennifer Francis’ idea concerning Arctic sea ice extent and the jet stream, there might be a case for expecting the predominant patterns to persist, with the exception of the PNA, which has a relationship with the PDO and ENSO.

What would that mean for the EPO and AO?

The EPO has been variable this meteorological winter:

December 1-4: Positive (4 days – 15 days if November is included))
December 5-17: Negative (13 days)
December 18-28: Positive (11 days)
December 29-January 11? (14 days)

Basically, the EPO has been changing states every 10-15 days. While such a near regular oscillation may not necessarily continue, the idea that the forecast period of a positive EPO that lies ahead would again give way to an EPO- probably has merit.

The AO has currently been positive for 35 of the first 41 days (85%) of meteorological winter. Dr. Francis’ work might argue for the continuation of a generally positive AO.  11/15 (73%) of December cases with an AO average of +1.000 or above were followed by a positive January average.

Nevertheless, there may also be reason to cautiously expect some increase in the number of AO- days in the longer-term (very late January through February timeframe). Of those December cases, 47% had a negative AO average for February. While 36% of the January AO+ subset had a negative AO average in February, 50% of those positive January cases with a monthly AO average < +1.000 had a negative value in February.  The January 1-10 preliminary AO average is +0.652 and the guidance does not currently show any of the very strongly AO+ values that occurred in December (+3.000 or above).

Overall message: The multi-week (probably about 2 weeks) period of generally warmer than normal conditions in the East (with an interruption this weekend) does not mean the end of winter 2016-17. February may actually produce some good opportunities for cold and snowfall (regardless of what the CFS may imply right now).

PNA01102017.jpg

Link to comment
Share on other sites

2 hours ago, Morris said:

Low of -3 in Westhampton.

15 in Newark.

21 in the park.

..thats 2 nites in a row below 0 for KFOK..my low was 5.2*.

KFOK had 14 consecutive hours of single digit temps(w/ some hours below zero)..you

would think the ponds would be ready for some hockey..and they probably are but the crusty snow

cover says..no bieno!

Link to comment
Share on other sites

2 minutes ago, tim said:

..thats 2 nites in a row below 0 for KFOK..my low was 5.2*.

KFOK had 14 consecutive hours of single digit temps(w/ some hours below zero)..you

would think the ponds would be ready for some hockey..and they probably are but the crusty snow

cover says..no bieno!

ISP also had a low of 6°, just missing the record of 3° set in 2004.

Link to comment
Share on other sites

1 hour ago, bluewave said:

The Arctic shot ends dramatically at FOK closing in on a 40 degree temperature rise off the low.

 

go.cgi.gif

 

 

I have noticed allot of these senerios over the years out there. They end a cold shot with some ridiculous low below zero only to have the wind switch south during the morning and rapidly shoot the temp up to 40. It's got to be some of the fastest temperature rises in the entire country If not world. Up there white a chinnock wind on the Great Plains 

Link to comment
Share on other sites

3 hours ago, tim said:

..thats 2 nites in a row below 0 for KFOK..my low was 5.2*.

KFOK had 14 consecutive hours of single digit temps(w/ some hours below zero)..you

would think the ponds would be ready for some hockey..and they probably are but the crusty snow

cover says..no bieno!

Ours here in cnj dont have a snowcover buy they will be melting by tomorrow 

Link to comment
Share on other sites

11 minutes ago, uncle W said:

4 on Feb. 13th, 1967 to 60 on the 15th, in NYC...I bet parts of N.J. had a larger spread...

Toms River was -4 this morning and the Euro has 63 on Thursday. A few degrees more than that and they will be pushing a 70 degree 2 day rise.

Link to comment
Share on other sites

5 hours ago, donsutherland1 said:

Last evening, I noted the relationship between the PDO and PNA. During the January 1950-2016 period, PDO- values coincided with PNA- values 62% of the time and PDO+ values coincided with PNA+ values 73% of the time. Since December 23, the PNA has been negative, although it rose to -0.232 on January 9 (preliminary value).

The ensembles are continuing to show the return of a PNA+ in the medium-term. What is new is that a number of ensemble members are now suggesting that the PNA+ could be sustained. It’s still a little early to be confidence in such an outcome, but the relationship between the PDO and the continuing fade of the recent La Niña event argue for an increased prospect of PNA ridging (PNA+) as the winter continues to progress.

Borrowing from Dr. Jennifer Francis’ idea concerning Arctic sea ice extent and the jet stream, there might be a case for expecting the predominant patterns to persist, with the exception of the PNA, which has a relationship with the PDO and ENSO.

What would that mean for the EPO and AO?

The EPO has been variable this meteorological winter:

December 1-4: Positive (4 days – 15 days if November is included))
December 5-17: Negative (13 days)
December 18-28: Positive (11 days)
December 29-January 11? (14 days)

Basically, the EPO has been changing states every 10-15 days. While such a near regular oscillation may not necessarily continue, the idea that the forecast period of a positive EPO that lies ahead would again give way to an EPO- probably has merit.

The AO has currently been positive for 35 of the first 41 days (85%) of meteorological winter. Dr. Francis’ work might argue for the continuation of a generally positive AO.  11/15 (73%) of December cases with an AO average of +1.000 or above were followed by a positive January average.

Nevertheless, there may also be reason to cautiously expect some increase in the number of AO- days in the longer-term (very late January through February timeframe). Of those December cases, 47% had a negative AO average for February. While 36% of the January AO+ subset had a negative AO average in February, 50% of those positive January cases with a monthly AO average < +1.000 had a negative value in February.  The January 1-10 preliminary AO average is +0.652 and the guidance does not currently show any of the very strongly AO+ values that occurred in December (+3.000 or above).

Overall message: The multi-week (probably about 2 weeks) period of generally warmer than normal conditions in the East (with an interruption this weekend) does not mean the end of winter 2016-17. February may actually produce some good opportunities for cold and snowfall (regardless of what the CFS may imply right now).

PNA01102017.jpg

Fantastic read, Don. Thank you.

Link to comment
Share on other sites

1 hour ago, LongBeachSurfFreak said:

I have noticed allot of these senerios over the years out there. They end a cold shot with some ridiculous low below zero only to have the wind switch south during the morning and rapidly shoot the temp up to 40. It's got to be some of the fastest temperature rises in the entire country If not world. Up there white a chinnock wind on the Great Plains 

They are close to the coldest place on the island with no wind and the warmest place on the island with a south wind.  Even without a south wind, after sunrise the FOK temp rockets.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...