Jump to content


  • Content count

  • Joined

  • Last visited


About donsutherland1

Contact Methods

  • Website URL

Profile Information

  • Four Letter Airport Code For Weather Obs (Such as KDCA)
  • Gender
  • Location:
    New York
  1. January 2018 Discussions & Observations Thread

    The New York City area is now in the midst of a more sustained period of warmer than normal readings. As the milder weather rolls on, it might be tempting for some to forget that January has been a snowy month in the greater New York City area. Some snowfall statistics through January 19: Bridgeport: January: 9.3”; Season-to-date: 18.0” Islip: January: 16.0”; Season-to-date: 22.0” New York City: January: 10.2”; Season-to-date: 17.9” Newark: January: 9.4”; Season-to-date: 17.1” New York City’s Average Temperature Through: 1/19: 26.8° (5.6° below normal) 1/20: 27.6°-27.9° (1/19 estimate: 27.5°-27.8°) 1/25: 30.0°-31.2° (1/19 estimate: 29.7°-31.1°) 1/31: 31.5°-33.7° (1/19 estimate: 31.1°-33.5°) Per aggressive sensitivity analysis, the estimated probability of a below normal monthly anomaly: 50% (1/19 estimate: 52%) The second and more sustained part of the January thaw is now unfolding. Initially, with the AO having gone negative again, there might be some fleeting and modest shots of cooler air. However, remaining 12 days of January will likely feature a warmer than normal anomaly for the period as a whole. However, this is a thaw, not the unofficial end of winter. In the longer-range, there are growing indications that the familiar EPO-/AO-/PNA+ pattern will take hold in February. In terms of a timeline, this is how I currently see things: January 20-31: Generally warmer than normal with perhaps a short-duration shot of cooler air (somewhat below normal to near normal for a day or two). Lower than climatological probability of snowfall. February 1-7: A transitional period. The AO should go negative, if it went positive preceding this period. The trough in the west begins to migrate eastward. Temperatures remain above normal for the period as a whole, but there might be another temporary shot of cooler air. Lower than climatological probability of snowfall, but the probability could begin to increase toward the end of the period. February 7-10: The trough reaches eastern North America (possibly centered over southeastern Canada), probably near the end of the period. It then locks in for 3 to possibly 4 weeks. Support for this scenario is shown on the CFSv2 and EPS weekly guidance.
  2. January 2018 Discussions & Observations Thread

    Yesterday was the 12th day this month that the temperature fell below 20° at Central Park. The last time any month had at least as many such days was February 2015 when the temperature fell below 20° on 18 days. The last January with at least 12 such days was January 2015 when there were 13. The 12 such days this month is more than the total for winters 2015-16 (9) and 2016-17 (10). New York City’s Average Temperature Through: 1/18: 26.5° (5.9° below normal) 1/20: 27.5°-27.8° (1/18 estimate: 27.4°-28.0°) 1/25: 29.7°-31.1° (1/18 estimate: 29.2°-30.8°) 1/31: 31.1°-33.5° (1/18 estimate: 30.4°-32.9°) Per aggressive sensitivity analysis, the estimated probability of a below normal monthly anomaly: 52% (1/18 estimate: 57%) At this point, the worst of January’s cold is now behind us. Through at least the medium-term, no additional sub-20° minimum temperatures appear likely for New York City. With some of the guidance, the overall probability of a colder than normal January fell sharply overnight. However, winter will likely only be “resting.” It very likely is not finished. Additional cold and quite a bit of snow likely still lie ahead.
  3. January 2018 Discussions & Observations Thread

    2010-11 wasn't a close match, though there had been a possibility of 2010-11-type snowfall in a highest-case scenario. 2000-01 was the closest match.
  4. Clearly, the rise of Social Media has made near real-time analyses and updates feasible. Many look forward to such fresh information. However, there is a real quality issue. Sensationalism is all too common (often with the most extreme model maps being posted for upcoming events). Plain misunderstanding of complex relationships is another one e.g., I recall one Twitter account was suggesting that a high-amplitude MJO event during June 2015 was unusual for what was a rising El Niño event when, in fact, during that time of year such events often take place during strengthening El Niños on account of shorter wave lengths. Overly deterministic assessments that ignore uncertainty is another matter. Having said this, on balance Social Media has been beneficial in the dissemination of meteorological information. But to realize such benefits, one needs to be able to differentiate between quality sources and others. Many who actively participate on various weather forums can readily differentiate. I'm not so sure the less engaged general public can.
  5. January 2018 Discussions & Observations Thread

    Last winter, there were two such cases where accumulating snow followed 60° days: February 8, 2017: High: 62°; February 9: 9.4" snow March 9, 2017: High: 61°; March 10: 2.1" snow
  6. Joe Lundberg is still listed on the Accuweather site: https://www.accuweather.com/en/personalities/joe-lundberg In addition, he is referenced on the WHUD radio site (noting his affiliation with Accuweather): http://www.whud.com/meet-the-whud-djs-joe-lundberg/ He simply might not be blogging any longer.
  7. January 2018 Discussions & Observations Thread

    The idea that the second half of the January thaw, which has seen some interruptions, would feature the longest period of sustained warmer than normal anomalies still appears on course. Around a week ago, I had some concern based on 500 mb pattern recognition that the AO could turn positive (this was a separate development from the nearer-term idea of the currently positive AO, which will end in the next day or two) during the January 20-25 period. The 500 mb pattern suggested a transition of sorts in the AO region. This idea gave me further confidence that the second half of the thaw would see more sustained warm anomalies that the front half. The guidance is hinting at such a possibility. Back then, I noted: Given some of the 500 mb forecasts on the ensembles, I could see the AO going positive for a time in the January 20-25 timeframe, even as the majority of ensemble members keep the AO negative. Such an outcome would increase prospects for above to possibly much above normal readings during the closing days of the thaw. During the January 20-30, 1981-2010 base period, the mean temperature for a PNA of -0.75 or below/AO+ is 39.6° vs. 31.9° for climatology. https://www.americanwx.com/bb/topic/50695-january-2018-discussions-observations-thread/?do=findComment&comment=4768918 Overnight, the GEFS has turned strongly to that idea (see attached image). In my view, this is not a bad development. Instead, it is the kind of transition that has often preceded a return to sustained blocking. It's the development of such blocking that will prove important in influencing the long-term February outcome. Right now, I remain confident in the return of the EPO-/AO-/PNA+ pattern that has defined winter 2017-18 so far. Before then, I suspect it will be at least a week before there are any snowfall opportunities for the NYC area (probably at least through 1/25). It remains possible that there could be an event that brings at least some measurable snow before the end of January, but that would be a bonus in what has been a snowy month.If things work out the way I am thinking right now, the first week of February will likely mark a transition. Then, there will be a 3 to perhaps 4-week period of frequently colder than normal weather (not unbroken) with above climatological probabilities of measurable snowfall. Considering that numerous La Niña-PDO winters have featured a 12" or greater snowstorm in NYC (and nearby regions), there could be a possibility of a large snowstorm at some point in February.
  8. January 2018 Discussions & Observations Thread

    Yesterday’s snowfall has likely marked the last measurable snowfall for a large part of the region for at least the next 7 days. However, the pause in snowfall does not mark the end of winter. The latest PDO data has become available. The PDO rose to +0.50 in December. Since 1950, 72% of cases where the December PDO > 0 led to a January-February PDO average > 0 and 90% of cases where the December PDO was +0.25 were followed by a January-February PDO average > 0. As a result, this data suggests that winter 2017-18 is very likely to wind up being a La Niña-PDO+ winter. La Niña-PDO+ winters tend to be much snowier than La Niña-PDO- winters. Mean and median seasonal snowfall figures for the former category are 40.0” and 35.0”. The respective figures for the latter category are 20.1” and 15.9”. 60% of the five La Niña-PDO+ winters saw 30” or more seasonal snowfall and none had less than 20”. In contrast, just 13% of the sixteen La Niña-PDO- winters received 30” or more snow while 63% picked up less than 20”. In addition, a positive PDO tends to favor a PNA+. This data suggests that the predominant winter pattern of a PNA+ is likely to resume following the modeled period of a PNA-. Based on the long-range guidance hinting at a return of EPO-/AO- blocking, the PDO+ favoring a PNA+, and experience with winters where a December storm brought 4” or more snow from Philadelphia to Boston, winter 2017-18 appears well on track to be snowier to much snowier than normal in much of the Middle Atlantic and southern New England areas. The odds appear to favor a snowy February. New York City’s Average Temperature Through: 1/17: 26.6° (5.9° below normal) 1/20: 27.4°-28.0° (1/17 estimate: 27.4°-28.3°) 1/25: 29.2°-30.8° (1/17 estimate: 29.6°-31.5°) 1/31: 30.4°-32.9° (1/17 estimate: 30.0°-32.7°) Per aggressive sensitivity analysis, the estimated probability of a below normal monthly anomaly: 57% (1/17 estimate: 58%)
  9. 1/16-17 Anafrontal/Coastal Low Snows Disco/Obs

    Two photos from the New York Botanical Garden this afternoon:
  10. 1/16-17 Anafrontal/Coastal Low Snows Disco/Obs

    Many thanks. I truly appreciate it.
  11. 1/16-17 Anafrontal/Coastal Low Snows Disco/Obs

    Great photos. Would you mind if I added them to my site with credit given?
  12. 1/16-17 Anafrontal/Coastal Low Snows Disco/Obs

    Snowfall totals: 865 NOUS41 KOKX 172019 PNSOKX CTZ005>012-NJZ002-004-006-103>108-NYZ067>075-078>081-176>179-180819- Public Information Statement Spotter Reports National Weather Service New York NY 319 PM EST Wed Jan 17 2018 The following are unofficial observations taken during the past 6 hours for the storm that has been affecting our region. Appreciation is extended to highway departments, cooperative observers, Skywarn spotters and media for these reports. This summary also is available on our home page at weather.gov/nyc ********************STORM TOTAL SNOWFALL******************** LOCATION STORM TOTAL TIME/DATE COMMENTS SNOWFALL OF /INCHES/ MEASUREMENT CONNECTICUT ...Fairfield County... New Fairfield 4.2 215 PM 1/17 Trained Spotter Bridgeport Airport T 100 PM 1/17 CO-OP Observer ...New Haven County... Southbury 2.4 230 PM 1/17 Fire Dept/Rescue Waterbury 1.8 1200 PM 1/17 Trained Spotter Wallingford 1.3 1000 AM 1/17 Amateur Radio Hamden 0.5 950 AM 1/17 Amateur Radio NEW JERSEY ...Bergen County... Franklin Lakes 3.1 100 PM 1/17 Public Westwood 2.2 150 PM 1/17 Trained Spotter Mahwah 1.9 942 AM 1/17 Trained Spotter Englewood Cliffs 1.1 215 PM 1/17 Trained Spotter East Rutherford 0.9 1200 PM 1/17 Trained Spotter ...Essex County... West Orange 2.5 1130 AM 1/17 Public Cedar Grove 2.5 1110 AM 1/17 Public ...Hudson County... Harrison 1.0 1139 AM 1/17 Trained Spotter ...Passaic County... Bloomingdale 3.1 1107 AM 1/17 Trained Spotter Ringwood 2.2 1200 PM 1/17 Trained Spotter ...Union County... Newark Airport 1.0 100 PM 1/17 FAA CONTRACT OBSERVER NEW YORK ...Bronx County... Bronx 1.0 100 PM 1/17 Trained Spotter ...New York County... Central Park 0.4 100 PM 1/17 Park Conservancy ...Orange County... Otisville 8.0 1136 AM 1/17 Public Westtown 6.2 1200 PM 1/17 Social Media Montgomery 6.1 1110 AM 1/17 Emergency Manager Monroe 6.0 1240 PM 1/17 Trained Spotter Newburgh 5.8 230 PM 1/17 Trained Spotter Gardnertown 5.0 1016 AM 1/17 Trained Spotter New Windsor 4.5 1100 AM 1/17 Public Warwick 4.5 1025 AM 1/17 Social Media Rock Tavern 4.5 1200 PM 1/17 Trained Spotter ...Putnam County... Brewster 2.8 930 AM 1/17 Social Media Sunnybrook 2.3 230 PM 1/17 Broadcast Media ...Queens County... Bayside 0.8 208 PM 1/17 Social Media NYC/JFK Airport 0.2 100 PM 1/17 FAA CONTRACT OBSERVER NYC/LaGuardia Airpor 0.1 123 PM 1/17 FAA CONTRACT OBSERVER ...Richmond County... Staten Island 0.8 210 PM 1/17 Social Media Oakwood Heights Stat 0.4 1200 PM 1/17 CoCoRaHS ...Rockland County... New City 1.6 115 PM 1/17 Trained Spotter ...Suffolk County... Islip Airport T 100 PM 1/17 FAA CONTRACT OBSERVER Upton T 115 PM 1/17 NWS OFFICE ...Westchester County... Ardsley 1.5 1000 AM 1/17 Public &&
  13. 1/16-17 Anafrontal/Coastal Low Snows Disco/Obs

    The ground is whitened in Yonkers. Even streets are starting to be covered.
  14. January 2018 Discussions & Observations Thread

    Parts of the region are seeing snowfall this morning, while other areas closer to the City and eastward are experiencing a cold rain or even some freezing rain. A period of accumulating snow still appears possible for the City as colder air wraps around the developing system’s circulation. A slushy inch or two remains within the realm of possibility. In the past hour, Danbury has switched over to snow and snow has begun to mix into the rain in Newark and just west of Newark. Interior sections, many of which have been receiving snow at varying rates since yesterday remain in line for the largest accumulations. Afterward, the probability of snowfall will be below to much below climatology for at least the next 7 days. Nevertheless, January 2018 will wind up in the record books as having seen above normal snowfall across the region. New York City’s Average Temperature Through: 1/16: 26.5° (6.0° below normal) 1/20: 27.4°-28.3° (1/16 estimate: 27.3°-28.5°) 1/25: 29.6°-31.5° (1/16 estimate: 30.0°-32.2°) 1/31: 30.0°-32.7° (1/16 estimate: 30.3°-33.2°) Per aggressive sensitivity analysis, the estimated probability of a below normal monthly anomaly: 58% (1/16 estimate: 56%)
  15. 1/16-17 Anafrontal/Coastal Low Snows Disco/Obs

    Interesting model battle between the 3 km NAM/RGEM (with 1" or more snow in NYC) vs. the GFS/12 km NAM (< 1" in the City). All are in agreement about the heaviest snow being well to the north and west of the City into New England.