Friday, October 30, 2009

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"Break it down again"
Tears for Fears, from the 1993 album Element

SUN 11/01/09, 8:00 AM  SYNOPSIS and UPDATES:
- Significant winter weather in Mid-Atlantic between 11/15 and 12/5;
- Large pool of -30 C air building in Canada at 5,000 foot level;
- A southward push of air may accelerate forecast to before 11/15;
- Two computer models hinting at large coastal storm from 11/10-12;
- If scenario develops, 11/10-15 daytime highs in MD ~ 35 F or colder.

OVERVIEW: As we turn the corner into November, it is worth taking a moment to "break it down again" with regard to predicted timing of the early winter pattern, and the precise climate data sets. Eventually, both time and the data will support or refute my projection that winter weather arrives throughout the Mid-Atlantic region between 11/15 and 12/5. It should also be noted that my ideas do not assume long periods of below normal temperatures (ex. 1977-78), but rather short bursts of cold and snowy weather. I do agree with the ideas presented by some forecasters, including Meteorologist and DC Weather Examiner Allan Huffman. His professional and detailed analyses suggest a stormy but not extensively cold winter for the Mid-Atlantic due in part to warming influences a strengthening El Nino could produce, among other factors.

COMMENT COMMUNITY: If you are a new reader to the site, I extend a warm welcome to join our discussion community. At the bottom of each post, you will find a pleasant environment of weather enthusiasts where all viewpoints are respected, and healthy disagreement is treated as an important part of the public discourse.


1. BASIC PROJECTIONS: The current "lakes cutter" pattern I believe will shift back to the East Coast within two weeks. If this shift aligns with several climate teleconnections that suggest a return to cold EVEN BEFORE 11/15, the potential remains for a surprisingly early arrival of significant winter weather into the Mid-Atlantic.

2. GENERAL CLIMATE & WEATHER TRENDS: The fading and less-than-active hurricane season has permitted sea surface temperatures in the Gulf of Mexico and western Atlantic to remain at or above normal. This has enhanced warm moisture advection into developing systems. The biggest Colorado snowstorm in 12 years is continuing evidence of this trend, clearly demonstrating the influence a strong subtropical jet can have in delivering moisture from the the East Pacific. Other indicators:

- Recovery of Northern Hemispheric snow cover, notably in Eurasia;
- Strengthening El Nino signature (warming to 1.4 C in region 4);
- Favorable North Pacific ocean temp pattern (PDO:  0.09 in Aug / 0.54 in Sep);
- Solar cycle status similar to 1901-03, similar anomalous Autumn temps.
3. ANALYZING CLIMATE DATA IN 3 SPHERES: Using a global data approach from the Hydrosphere, Atmosphere and Cryosphere in order to tie together the concepts of large-scale teleconnections with winter patterns. For example, presenting in a concise and useful way indications revealed by trends in the QBO, PDO and ENSO cycles.

4. SO CONCENSUS IS: "Cold and snowy?"
I have not seen the Farmer's Almanac predictions, nor thoroughly read anyone's winter forecasts. I have glanced at one referenced earlier, and skimmed those produced by Accuweather and NOAA. Instead, I follow the data on my own, and check on analyses by other researchers on forums such as Eastern US weather. When citing their research in my work, credit to the source is routine, and there have never been accusations to the contrary. If my pattern ideas continue to play out, it could unfold in this manner:
  • 11/01-09: A mild to cool period then brief warmup;
  • 11/10-15: Possible outbreak of Arctic air on or before 11/15;
  • In same week, a "smackdown" storm with snow at the onset;
  • 11/15-25: "yo-yo" period of below then above-normal temps;
  • 11/25-12/5: Seasonal temps leading to kickoff event by 12/5.
CONCLUSION: Once the pattern shifts as outlined above, the Eastern US will be clocked with a fast-moving winter storm not unlike those which moved through Colorado this week and surprised central Pennsylvania in mid-October. Above-normal snow has also been observed in central Europe allowing many ski resorts across the Alps to open early.

ADDENDUM: Long-time powderhounds know my penchant for quoting Enya in times of snow and storms. I've maintained a position that the atmosphere is primed and ready to deliver, all we wait for now is "Only Time." I realize we haven't dug out the Thanksgiving decorations yet, but I can't resist the urge to tell you that before long, we will be reveling in the sight of "White in the Winter Night."

Wednesday, October 28, 2009

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6:00 AM Friday, 10/30/09. [Supporting details added in conclusion] In continuing with our symposium on the upcoming winter pattern, this starts the second set of topics as outlined in the previous post (Part 2: Identifying the climate data ; Part 3: Laying out a storm projection calendar). For starters, we can ferret out some important FYI's for planning purposes:

1. HURRICANE RICK and the EARLY WINTER PATTERN: The Saturday 10/24 frontal passage, which delivered up to 1.5 inches of rain in a few hours across the Northeast I-95 corridor, was associated with remnants of once-Category 5 Hurricane Rick. Prior to making landfall along the Baja peninsula, Rick's maximum sustained winds were clocked at 180 mph for at least 12 hours, making this the strongest East Pacific Hurricane in 10 years. Why is that crucial to the winter forecast? I hypothesize that Rick's rapid intensification was driven by El Nino-influenced sea surface temperature anomalies SSTA's off the west Mexican coast. Both the hurricane and the system currently moving through the eastern U.S. featured rapid and expansive moisture transport from the eastern Pacific and Gulf of Mexico. There remain a multitude of other important climate influences driving the potential for a snowier winter in the Eastern US (including the Pacific Decadal Oscillation, the Quasi-Biennial Oscillation, among others.) Effect of those indicators will be outlined in greater detail within the next several weeks.

As other forecasters and weather outlets have suggested, an active southern storm track combined with a below-normal temperature regime for December across the Eastern US increases probability the Mid-Atlantic experiences several large, disruptive winter storms. My analysis of the pattern evolution suggests that Hurricane Rick's October 20-24 impact launched a second 6-week pattern (as outlined in the previous post), which would conclude by December 5. I propose that at least one significant snow event occurs in the Mid-Atlantic and by 12/5, ending a stormy pattern and transitioning to a long period period of below normal temperatures for most of December.

2. THE TEMPERATURE YO-YO: The chilly, rainy period from October 15-18, which made Baltimore's daytime highs of 43-45 seem more like December set in motion the temperature pattern which continues to play out. This was followed by the seasonal to above-normal temperature regime of October 19 to 23 prior to Hurricane Rick's rain. This out-of-balance temperature activity may also have contributed to the pattern shift which I believe will bring winter weather to the Eastern U.S. more quickly than we are accustomed. A recent time frame for comparison would be October to December 2002 as one example of long-duration unstable temperatures during a moderate El Nino in Autumn. What followed was a December 4 to March 1 period delivering 55 inches of snow to the Baltimore region.

CONCLUSION: I believe residents of the Mid-Atlantic region have 3 weeks to complete their usual winterizing preparations (notwithstanding central PA of course). Time is getting very short to finish remaining outdoor/summer cleanup, winterizing the home, switching out your clothes, getting your vehicle and transportation procedures in order. I project the region's first winter storm arrives anytime after mid-November (11/15) to early December (12/5). I also expect this event to be significant, drop a lot of snow quickly over a large area, and leave a long stretch of very cold weather in it's wake. For reference, this first event may bear similarity with three early season Mid-Atlantic storms: the Veteran's Day Storm of November 1987, the White Thanksgiving of 1989 or the December 1992 Appalachian Storm. The 1989 event was followed by a multi-week Arctic outbreak which set many eastern U.S. records for one of the coldest Decembers. Additional sources: 2000 AMS Online Journal article, Data table. In deference to meteorologists and weather-enthusiasts whom follow this site, it should be noted that reference to these three storms does not imply this year's winter pattern will resemble the year in which they occured. Those events are provided for climatological reference for readers looking for comparison of current ideas with previous events. With a moderate-to-strengthening El Nino and an already active subtropical jet, Mother Nature is giving us a clear heads up that the game is about to begin. Is your team ready?

Note to new readers: This site is operated as an on-going symposium where teachers, meteorologists, snow enthusiasts, students and parents alike share or compare ideas on the analyses presented. Your input, for or against, is welcome anytime in the comment section below.

Monday, October 19, 2009

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Note to students: For this week's assignment, follow these links below. Stay focused, do your best, and if there are any questions about the assignment, I can be reached via this address: Sincerely, Mr. Foot


To get the current El Nino data for this week: click on the last link above, press the "page down" key on your computer until you reach page # 4. There you'll see the current data.


The Foot's Forecast Winter 2009 SYMPOSIUM

What does "December in October"
mean for the Mid-Atlantic region?

SUMMARY: The occurence of 20- to 25-degree below normal temperatures in October may have disrupted the seasonal pattern such that the Eastern United States may not return to long periods of normal weather for several months. The effect of this early cold period now may produce a brief warmup in November followed by a major cold outbreak and an inland snow event. A rapid onset of persistent and disruptive winter weather is expected by December 5. If this unstable pattern continues, as was observed in October-December of 2002, areas of the Mid-Atlantic region could experience widespread school closings for 2 or more days this December. This may equal or exceed the cold and snowy period observed in the Baltimore region from December 4-11, 2002.

PART 1: HYPOTHESIS. The stormy pattern along the Northeast and Mid-Atlantic was transitioned into place by three coastal storms including Tropical Storm Danny during Aug 26-29, rainstorms of 9/6-12 and 9/24-28. The absence of hurricanes in the Gulf of Mexico thus far, combined with a stable El Nino Cycle has produced warmer than normal sea surface temperatures over very large areas. Warmer seas can permit more rapid evaporation of moisture into developing low pressure systems tracking across the southwest and along the southeast. The October 12-13 midwest snowfall, and the October 15-18 Early Autumn storm are indicators of how climate teleconnections are interacting to produce unseasonal regional weather events.

PART 2: CLIMATE DATA Most of us in weather and climate community, either professional, amateur or the public, accept that we may never understand all the factors driving winter patterns. Each year on this website, I attempt to expand the dialogue on those factors based on knowledge gained from research, observations from readers, and simply tracking the data more closely. For this year, the monitoring criteria for a potentially significant winter is much greater than before - so the "laundry list" approach has to be employed for efficiency. Whether you are a frequent or new reader, this data list is designed to familiarize with the acronyms and definitions tracked here. I will be training my Science students to monitor the list in order to provide you with the most spot-on perspective on what may be influencing our weather over the next six months.

A) Hydrosphere Data (Tracking specific cycles, seasonal trends and indices about ocean temperatures and influence on atmospheric activity)

1) ENSO Cycle (+0.7 to +1.0 C as of 10/12/09): defined as current status of the El Nino Southern Oscillation Cycle as reported by the US Climate Prediction Center in a brief diagnostic discussion as well as the weekly ENSO update.

2) PDO Index (positive phase as of 10/8/09): The Pacific Decadal Oscillation is defined as monitoring the "leading principal component of North Pacific monthly sea surface temperature variability (poleward of 20N for the 1900-93 period)." Researchers at the University of Washington suggest that "combining ENSO and PDO information may enhance the skill of empirical North American climate forecasts." Sources: UWA, Climate Impacts Group.

1) SSTA (Data pending): Defined as sea surface temperature anomalies for the Gulf of Mexico and West Atlantic. The American Meteorological Society states in a February 2003 journal article that "Using a combination of statistical methods and monthly SST anomalies (SSTAs) from one or two ocean regions" there are strong correlations between sea surface temperatures and precipitation during much of the year in the United States."

2) 2009 Hurricane Season (Data pending): Defined as the frequency and track of tropical cyclones in the Atlantic basin. It is hypothesized for discussion that a less active hurricane season combined with a positive ENSO cycle may correlate to increased probability of significant winter storms in the Eastern United States in the following six month period from October to March. Historical data supporting this hypothesis will be provided.

B) Cryosphere (Monitoring specific data sets about the frozen part of the northern hemisphere's polar water system)

1. Arctic sea ice (5.27 mil sq. km as of 9/28): Defined as the total surface area in million square kilometers of sea ice within the Arctic Circle as reported weekly by the National Ice Center.

2. N. Hemispheric snow cover (data pending): Defined as a visual interpretation and data on extent of snow cover across the United States, Canada, Russia, Northern Asia and Europe

C) Atmospheric Data (Monitoring quantitative indices which track variability in atmospheric teleconnective patterns, such as how might air pressure changes over Greenland affect the track of a US East coast storm). Note: Data and info for this section posted later Sunday.

NAO: North Atlantic Oscillation Index (my preferred "local teleconnection" that reveals much about current weather, upcoming pattern changes, storm tracks and cold outbreaks)
PNA: Pacific-North American Index
MJO: Madden-Julian Oscillation Index (wildly intriguing atmospheric hiccup that has been suggested by some is a major factor in the ENSO cycle-- details later.)
QBO: Quasi-Biennial Oscillation Index (interesting pattern relationships between easterly or westerly phase of this index, current solar cycle and latitude variation of North Atlantic winter storms.) Source: 1988 article in the journal Geophysical Research Letters.
now this one's a toughie..
AAM: Axial Angular Momentun of the Atmosphere. (you better take some Tylenol before we go over this.)

D) Solar Cycle (data pending): Defined as the monthly mean, frequency and duration of sun spots as an influential factor in Earth climate)

PART 3: PROJECTED STORM EVENTS for November and December 2009. A prediction calendar to be posted here and in the sidebar links for those interested in tracking both the predictions and the progress of the data. In the spirit of our first annual "Winter Symposium," all appropriate and respectful input on this topic is welcome. All comments will be moderated before being posted to the public.

Mr. Foot
Science Teacher ~ The Crossroads Center
Baltimore County Public Schools

Sunday, October 18, 2009

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A snow-bound Beaver Stadium at Penn State University the day before Homecoming, October 2009. Photo credit: The Daily Collegian.

7:45 AM SUNDAY, 10/18/09. The earliest October snowfall in State College, PA since 1901 did not dampened homecoming spirits in Happy Valley. Although Beaver Stadium was snow-bound, the Penn State Nittany Lions emerged victorious from the 2009 snow bowl, with an ice-crushing 20-0 victory over Minnesota. Read all about the massive pre-game cleanup, the East Halls power outages, and snowed-out Paternoville at The Daily Collegian. Extensive tree damage and power outages continue across parts of the region as reported in the Centre Daily Times, State College, PA. Disclosure notice: Mr. and Mrs. Foot are Penn State graduates, class of 1996. We not-so-fondly remember the last snow bowl in November 1995, when Joe Paterno had to reprimand the student section for throwing snowballs into the field.