Monday, October 18, 2004


With the tropics quiet for a moment, it is time to release the official Foot's Forecast for Winter 2004-05. (Drum roll please....)

The map below is the basis of this forecast. What you are looking at is the departure from normal sea surface temperatures (SST) across the world. This is available on a daily basis from the link to the left, and it is one of the best indicators of what is to come for the winter, based on past trends. This map is produced by the U.S. Navy.

While it might seem to a casual observer a bit of a stretch to base an entire winter forecast on the ocean water temperature map of one particular day, let me give you some reasons why it is possible:

1. It takes a long time for the ocean to change temperature patterns, thus SST signals are like the performance of the stock market. Both are strong indicators of what is likely to happen down the road 4 to 6 months from now. I am confident with this forecast because the SST signals this October are much warmer than they were in October 2002, which led to the record-breaking snowy winter of 02-03, culminating with the February 2003 Blizzard on the East Coast.

2. Historical trends show that when the United States observed a cooler than normal summer with above normal hurricane activity, the result was the East Coast recorded a cooler than normal winter with above normal snowfall. The other strong predictor was the state of SST's off the West Mexican Coast and into the central Pacfic in mid-October. In more than 30 years of record-keeping, those signals led to a snowier winter for the East coast.

(Snow days refers to a snowfall of 5" or greater that closes Baltimore Metro region schools.)

Overall predictions: 6 snow days, accumulation total at BWI airport: 35" for the season.
60% or greater likelihood of a major snowfall exceeding 12" at least once during the season
80% or greater likelihood of a medium snowfall exceeding 6" at least twice during the season.

Rest of October: Overall normal to above normal temperatures

November: Cold to start, then warmer toward the end.
First hint of snow or flurries around the 15th.

December: Very cold early, then a stretch of mild weather from mid-month until early Jan.
Snow days: 1 within the first 10 days of the month.

January: Mild early, then a snapback to cold from mid-month to the end.
Snow days: 2 during the second half of the month.

February: Cold to start, then mild in the middle, then cold towards the end.
Snow days: 1 early in the month, 2 late in the month

March: The last occurence of accumulating snowfall no later than the 10th.

So now the fun begins as we get to tick off the days as winter approaches, and see how close the forecast will verify. I'm sure more than a few of you will keep me honest in this process.

No comments: