Friday, October 30, 2009

"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.

ROUGH GUIDE TO PATTERN ANALYSIS & IDEAS

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."

No comments: