Location: New York
Author: Weather 2000, Inc.
Date: Thursday, December 20, 2007
Northern States share some of their cold anomalies with the South...
December net results normalize to register on-target with researched Winter chronology across Nation.......
Weather Loose-Ends as people look toward 2008....
With the ongoing bombardment of weather "information", and its interplay with psychology, some more questions & concerns have been brought to our attention which we were asked to address. With popular forecasts overwhelmingly hot-hot-hot, and images of Palm Trees going to sprout up in Chicago, we wanted to raise a caution flag for those who may want to plan ahead for any potential "surprises", especially across the Northern U.S. (like we saw this month).
Rumor/Myth/Story #1: Winter is Over.
* This is a perennial favorite, originally instigated by industries who were locked into a paradigm that "their Winter" was made or broken before Christmas. Of course the record cold November-December 2000 (and ensuing moderation) only reinforced these beliefs, but in 2001 our climate research was beginning to show signs of a seasonal shift. Winters Seasons are now more ppropriately viewed & measured as January-March, with December being a kick-off month + April being a carry-over month, when decent ENSO conditions are present. Correspondingly within the past 12 years, 7 of the 8 coldest (Population/Gas weighted) November-December weeks were set back in 1995-2000 and 6 of the 9 coldest January-February weeks were recently set in 2002-2007.
Rumor/Myth/Story #2: Government Outlooks are Warm.
* Considering NOAA/CPC Outlooks always predict Warm every month (through all of 2008), for every region, and have been doing so year after year, it doesn't really say much. These outlooks are heavily comprised of Optimal Climate Normals [OCN] which essentially is a trend of the past Decade versus older climate averages this Century, which will almost always gives you a mathematical warm signal. Their next such 13-month outlook will be released this Thursday 12/20, and you can expect more of the same. In the past few years NOAA/CPC has provided a 30-Day outlook update on the last day of each month (for the upcoming month), and this can often show dramatic changes as medium-range model data is ncorporated. For example, their December Outlook released on November 15th depicted warm weather across the entire Nation, but their update on November 30th flipped to predict anomalous cold for the Upper-MidWest and Northeast, confining the anomalous warmth to the Southern U.S. You will likely notice similar flips in their 30-Day outlook updates throughout this Winter.
Rumor/Myth/Story #3: Mild Days = Mild Month/Winter.
* For a typical location, a standard "Cold" Winter might have 60 Below Normal Days for every 40 Above Normal Days. In very variable Winters that ratio may flatten to 55/45. So people might get confused how a forecast for a cold Month {Season} could also contain numerous mild Days {Weeks}. There are plenty of regions across the U.S. that have experienced, and will continue to experience a net-Warm Winter, but it's the net-Cold regions (even if the minority) that can pack an industry/financial punch in the Winter, so don't let volatility throw you of the trail.
Rumor/Myth/Story #4: Strong La Niņa = Winter A; Weak La Niņa = Winter B.
* There are plenty or meteorologists out there but the field of statistical climate prediction is very small & specialized, so short-term forecasters often extend beyond their area of expertise when asked about monthly/seasonal patterns and processes. This infamously happened in 2002 when El Niņo impacts were grossly over-simplified leading to popular calls for Northern Warmth, which conversely resulted in one of the coldest & longest Winters (2002-2003) for the Northeast Quarter of the Nation in 25 years. La Niņa is key element in the 2007-2008 Winter Season, but it is tremendously modified, enhanced, and re-shaped by dozens of other hemispheric oscillations at play. Strong La Niņa's can be Warm or Cold, Weak La Niņa's can be Warm or Cold, and the lessons learned in 2002-2003 from not compartmentalizing El Niņo intensities are not the same lessons that can be applied tocompartmentalizing La Niņa intensities. The same
information sources that are now emphasizing La Niņa generalizations are the same exact sources that stated this Summer that we wouldn't have La Niņa at all this year, which obviously should raise a red flag in your mind.
Rumor/Myth/Story #5: The Analog Year Winner is........
* Similar to the cookie-cutter approach of ENSO generalizations, analogs are quick, they are simple, and they are easy to grasp, but it is very slippery slope to walk down. The atmospheric processes at play each year are as unique as every snowflake; the number of permutations is enormous. It is perfectly proper to note that a location has had the most rainfall since 1999 or the most HDD's since 2000, but to provide a given year as a predictor of these to come, overlooks the important nuances, idiosyncrasies and chronologies every new Season has to offer.
Rumor/Myth/Story #6: Psychology Forecasting.
* While it's not a meteorological prediction, it does use meteorology to its advantage. For example, if one was to predict a Warm January in the North, it could appear that way following the very large negative anomalies experienced this December. If one was to predict a Warm February, it could appear that way in contrast to the frigid February of 2007. If one was to predict a Cold March, it could appear that way in contrast to the uneventful March of 2007. These are clever ways to spin perceived accuracy without verifying results. For some users, perceptions is in fact the name of the game, and for other users actual (objective) HDD tallies is the name of the game. Our site-specific predictions for month-by-month HDD's, precipitation, critical days, etc. were already made earlier in the Autumn upon request, so we'll continue to track verifications, forecast weather chronology, and call out important Winter developments that might be drowned out by spin.
Have a safe and enjoyable Holiday!
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