Before, during and after Hurricane Georges Doug Schaefer, 21 October 1998 Hurricane Georges was not an unusual hurricane; it just took the Ruta Panoramica (the longest possible path) across the island of Puerto Rico. Neither was it the strongest hurricane; it was stronger before it arrived here, and picked up a little steam later on while passing over Hispanola. The unusual thing about Hurricane Georges was that it selected a path over (almost) the maximum number of Caribbean residents possible, during a year when not much was expected of the Atlantic hurricanes. There were two reasons why 1998 was supposed to be an "off year" for Atlantic hurricanes. First, while El Nino is over, La Nina hasn't yet begun. La Nina years are supposed to be the worst for Atlantic hurricanes. Second is the quasi-biennial oscillation (QBO). Every two years or so (and the "or so" is why it's quasi), very high-altitude winds slosh back and forth over the Earth. When they slosh to the east (as in 1998) they oppose the (low-altitude) westerly trade winds in the tropics. This opposition causes wind shear (different wind directions at different altitudes) that interferes with hurricane development and westward movement. Notice that several other 1998 named storms (Ivan, Jeanne, Karl, and Lisa) retroflected (turned back to the east). The QBO caused that. But Georges snuck through. When Georges was well out in the Atlantic we looked for high or low pressure systems (steering currents) that might cause him to deviate from a path towards Puerto Rico, but there were none. As he approached the Antilles and the preparations began, we said "most of these storms turn to the north before Puerto Rico". That's right, they do. Stationary high pressure systems over the north central Atlantic typically are present to attract hurricanes away from Puerto Rico. This is why Hurricane Hugo missed most of the island in 1989. To a large extent this is why 90% of Atlantic hurricanes miss the little island of Puerto Rico. This is also what the steering currents did in 1995 (with the QBO sloshing to the west so there was no wind shear to interfere with the storms) to several hurricanes, including the massive Hurricane Luis of that year. In 1998 we lacked those steering currents. Not to get ahead of the story, but if 1995 Luis had taken 1998 Georges' path over Puerto Rico, many of us would not be here to tell about the trees and power poles knocked down this time around. By 18 September 1998 (Hurricane Hugo's 9th anniversary), the passage of Georges over at least part of Puerto Rico looked probable. This means that neither shopping for hurricane supplies (plywood, Vienna sausages, potato chips, beer) nor driving on public roads were feasible. The major problem was that Georges looked quite mean then, with 130 knot sustained winds. We did and drank what we could on Friday and Saturday. On Sunday morning the winds were strong out of the north. As any pre-Colombian Taino Indian could have told you, winds out of the north in the summer are bad news. Huracan is out there and he may be coming to visit. I tied down the loose stuff, put a climbing rope over the roof of my metal shed, and used the plywood I had to brace the sliding glass door. My neighbors bought cheap gasoline-powered generators (with which they continue to serenade me nightly). Antigua and St. Croix were hit hard. But Georges was now weaker; a category 2 hurricane, no longer a 4. Times have changed since the Tainos; now we have geostationary satellites, NOAA aircraft that jostle their way into the eye, the WWW, and The Weather Channel. Thus we knew that this would be more like the 1932 category 2 hurricane (San Ciprian) than the 1928 category 5 (San Felipe). Yet we were not very relieved because however it went there was no place to run and hide; the airports were closed, and the Vienna sausages might be running low. Sunday afternoon the outer rain bands and gusty winds came first. This part was not different from what we experienced in the 1995 near-misses by big storms (Luis and Marilyn) nor in the 1996 hits by small ones (Senoras Betsy and Hortense). But the barometer kept dropping, and the wind and rain kept rising. "Weak" or "strong", this hurricane was going to spend some time over this island. By 7:20 PM Monday night the winds were subsiding in Guaynabo, and there was no rain. We were in Georges' eye, and of course needed to go up on the roof to investigate. My notion of a hurricane eye was that there would be clear skies and stars overhead. This time "eye" was "closed", and the sky was full of clouds and cloud-strike lightning. By 7:35 the winds were increasing again, so it was time to hurry indoors and hide. The winds had shifted to out of the southeast, and they were noticeably stronger than before the eye. This was the windy and wet side of the storm, as advertised. The peak wind gust that I measured (40 minutes after the lowest barometric pressure, so the second eye wall) was 43.1 m/s (97 mph for non-metricians). The anemometer didn't exactly break but it stopped recording for the rest of the storm (I=m still not sure why). Anyway it seemed to be the actual peak wind, or at least nearly, and the winds subsided very gradually over the next 8 hours. I measured this peak 3 m above a flat roof so there is little doubt that the winds at treetop were gusting to 120 mph. And that the trees were disassembling. What still surprises me is, with all the wood that fell, that I didn't hear a single crack or crash. Just wind and rain against the house. About the rain. It only rained 1.5 inch before the eye, with 0.39 inch falling during 10 minutes just before the weather station took its vacation. A tipping bucket rain gauge can't go much faster than that. During the second half of the drama another 10 in of rain fell here in 8 hr, for which I am sorry to say I have to use the USGS data. This total led to much less landslides than did 1996 Hortense's 20 inches. George=s maximum rain in the island was over 24 inches in the central mountains. About the temperature. After falling 5 oC from 10 AM to 6 PM (large but perhaps not exceptional for a cloudy windy rainy day), it fell another degree in an hour, and rose a degree in the next hour in the eye. So the temperature "bump" in the eye was preceded by a "dip" in the leading eye wall. Makes me doubt the "friction explanation". After that, no data. Inside the house, it sounded like a hurricane, I guess. Sort of like someone was pressure-washing the outside of the house (later I found a few areas where the paint was actually blown off). The ABernoulli Effect@ over the rooftop sewer vent pipes caused the water in the toilet bowls to slosh up and down (interesting science? Gross? You decide). Rainwater was jetting in through the holes that I had drilled to run additional phone connections. That and the AMiami windows@ allowed flooding in all the upwind rooms. The high noise level and the possibility that something interesting might actually be said on the radio, meant little sleep that night. Next morning, Tuesday September 22, the wind was still strong and the rain continued, but it was time to start cleaning up. Downed wood was everywhere so I started to clear paths with the machete. For me the damage was only to trees, and to the fences that the wood fell upon. This clearing will take a few months of spare moments I suppose. Across the island, hundreds of wooden houses gave way, and I guess thousands of metals roofs moved westwards. I spent Tuesday night on roof listening to the storm=s passage over the Dominican Republic; many local stations were off the air so the reception was quite good. Also it was a cloudless night with extremely bright stars because San Juan and Caguas were not adding their usual light pollution. A rare view of the Milky Way from here; I didn=t think of it after earlier near-miss hurricanes which always seem to take down our electric power grid. There were also meteors radiating from both the south and north (a regular shower whose name I forgot?) adding to the show. Speaking of regular showers, they started out quite cool and bracing, until I remembered the solar shower thing (black plastic bag with a hose). Next night clear again so back to the roof. Wednesday night marked Georges= passage over Cuba and I could hear some local stations there, but particularly Radio Marti from Florida. This is a Voice of America anti-Castro station. They were doing a remarkable job putting Cuban expatriate callers on the air with their 800 number, and deftly mixing in what I can only describe as electronic espionage. I suppose that very little radio traffic in Cuba goes unheard by the CIA, etc. What Radio Marti put on was what different police or other local authorities were doing in different towns, essentially in real time. I do not suppose that all of this information was provided by Cuba through official channels. An interesting sidelight for us short-wave radio enthusiasts. As others have noted, there appears to be more damage to south side of the LEF than north. This may lead to some interesting comparisons since we have been for several months monitoring stream chemistry from sites all around the mountain. Just a bit of science mixed in to this personal diary. Beyond batteries and candles, I (and many others) are using car batteries and 12 volt bulbs. I prefer Alandscape lights@. My system is a little different because I am using solar panels to top up the battery. Five days after Georges, the brown hillsides looked even browner because the green leaves torn off were drying out. Twenty days after, many species are beginning to leaf out, and almost without our noticing it Puerto Rico is beginning to turn green again. But by my guess a half to a million tons of wood were laid down on the island (several of those tons in my yard!). How fast that turns into CO2 depends on the firestarters, the fungi, and the termites. How many tons of leaf N are released as N2O may be a very good question. One that we may answer? One month after Georges, the leaves are sprouting again on most trees. New utility poles are sprouting up everywhere, and according to the utilities we are at 90 to 95% reconnection. Such claims mean little here in the hills where the phone and electricity are still off, and the water is an intermittent dribble. There is a lot I might add about this Ahouse camping@ but it has become rather boring to describe. Perhaps it will end soon. For now we keep camping, cleaning, and collecting samples. The generators are always running nearby but I notice them less now. More hurricanes this year seem quite unlikely, but if La Nina appears in 1999, we will have a summer of preparing for near-misses (like 1995), or more diaries of direct hits (like 1998). In any case, 1995-1998 saw more Atlantic hurricanes than any other 4-year period of record. Something for global change folks to think about...