Linda and I are still discussing where we will go when BEOWULF is relaunched early next month. There are so many variables: family, time, our own interests, medical issues, and weather. Given the complexity of the variables, we figure we’ll make the final decision when we get back aboard. One of the issues we are looking at now is the worldwide weather pattern. This is a lot easier to keep track of on land, especially now that we have a high speed cable modem. Research is a breeze.

You are probably aware that this year is shaping up to be an El Nino event. In general terms, this usually means lighter trades in the Pacific, along with more Pacific cyclone activity – especially in French Polynesia. On the other hand, Atlantic hurricane activity is usually reduced during El Nino years.

El Nino/Southern Oscillation (ENSO) is the most important coupled ocean-atmosphere phenomenon to cause global climate variability on interannual time scales. Here we attempt to monitor ENSO by basing the Multivariate ENSO Index (MEI) on the six main observed variables over the tropical Pacific. (from http://www.cdc.noaa.gov/~kew/MEI/ )

The above is based on the general concept of what happens. Then, we went to the Univ. of Colorado website and looked at Prof. Gray’s update for this year’s Atlantic season. Bottom line, he’s indicating more activity than usual (compared to the prior period which has been generally weaker than the historic norm). The direct quote from the current abstract is:

Information obtained through March 2002 indicates that the 2002 Atlantic basin seasonal hurricane activity will, as with six of the last seven hurricane seasons, be above average. Though predictive signals from around the globe are mixed, most favor a continuation of above average hurricane activity. We believe we will have a warm Atlantic and favorable stratospheric winds are assured. The primary potential suppressing influence for this year’s hurricane activity is the further intensification of a weak El Nino. The predicted intensity of this El Nino event is likely to diminish this year’s hurricane activity but not nearly to the extent of the more powerful 1997, 1986-87, and 1982-83 El Nino events. We are lowering our 7 December 2001 forecast for 2002 by one storm. Most of our other TC predictors are still in line with an above-average hurricane season. We estimate that 2002 will have 12 named storms (average is 9.6), 65 named storm days (average is 49.1), 7 hurricanes (average is 5.9), 30 hurricane days (average is 24.5), 3 intense (category 3-4-5) hurricanes (average is 2.3), 6 intense hurricane days (average is 5.0), a Hurricane Destruction Potential (HDP) of 85 (average is 72.7) and overall Net Tropical Cyclone (NTC) activity of 125 percent of the average year for the period between 1950-2000. USÊlandfall probability is forecast to be above the long-term average owing to the combined effects of above-average NTC activity and the anticipated continuation of an above-average Atlantic Ocean thermohaline circulation and warm Atlantic sea surface temperatures.

Likely El Nino Conditions for 2002. ENSO is one of the principal global-scale environmental factors affecting Atlantic seasonal hurricane activity. Hurricane activity is usually suppressed during El Nino events (e.g., 1997). Conversely, activity tends to be enhanced during seasons with cold (or La Nina) water conditions (i.e., 1998-2000). We expect that this hurricane season will experience a weak to moderate El Nino event. This will likely be a modest suppressing influence on 2002 hurricane activity but is not expected to be a major inhibiting influence as were the very strong El Nino events during either 1997 or the events during 1986-87, 1982-83, and 1972 when the Atlantic thermohaline circulation was weak. Rather, we anticipate the El Nino characteristics during 2002 will be more typical of the weaker Nino events of the 1950s and 1960s (i.e., 1951-53-57-63-65-69). El Ninos also tend to be weaker when a westerly QBO is present and when the Pacific Decadal Oscillation (PDO) is negative, as it is now. Moreover, although ENSO conditions can be the single most important parameter dictating Atlantic seasonal hurricane variability when large warm or cold events occur, other properties of the atmosphere and ocean can be preeminent in years with weak to moderate El Nino or La Nina conditions.

So, what does all of this mean for our plans (and your own if you are headed for Europe or thinking of hanging out in the Caribbean or tropical S. Pacific for the hurricane season)? First, we are going to make sure we are out of the hurricane belt early. Assuming we head for Europe, we want to be heading to the Azores by the end of May. If we head to the East Coast again (unlikely), we’ll keep a very close eye on hurricane holes (and our neighbors). Returning from Europe – the Canaries – in late November, we’ll have to keep a sharp watch on late season hurricane activity. In the S. Pacific, even though Prof. Gray is saying this will be a weak El Nino, you still have to be extra careful in the E. Pacific. And if we decide to bring BEOWULF back to S. California for the summer, we’ll leave the Caribbean as early in May as possible, so we don’t have to deal with any early season activity in Central America or Mexico.

Listed below are a series of helpful URLs for El Nino and hurricane data.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ – Updated discussions from NOAA on El Nino progress

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensocycle/enso_cycle.html – A tutorial on the El Nino – La Nina cycle.

http://www.pmel.noaa.gov/tao/elnino/nino-home.html – El Nino Them page for NOAA

http://www.pmel.noaa.gov/~kessler/ENSO/soi-1950-98.gif – graph of El Nino and La Nina events over the last 50 years.

http://tropical.atmos.colostate.edu/forecasts/ – 2002 Atlantic Seasonal forecast by the famous Prof. Gray at Univ. of Colorado