IMPORTANT OPENING NOTE
Even if the sea surface temperature anomalies were to remain depressed throughout the 2014 hurricane season (highly unlikely), the actual sea surface temperatures (absolute) from June to November will rise to values capable of spawning hurricanes…a result of the normal seasonal change in surface temperatures. And while El Niño conditions in the Pacific tend to suppress hurricane development by effectively chopping the tops off the developing hurricanes (the result of wind shear in the tropical North Atlantic caused by the El Niño), hurricanes can still form and will likely do so this season.
There are many factors that contribute to hurricane development; one is seasonally elevated sea surface temperature in the tropical North Atlantic.
The hurricane season is approaching fast. With an El Niño developing, it’s likely the predictions for 2014 will be below normal for the season. Of course, the hurricane season will bring alarmist claims of strengthening storms brought on by higher-than-normal sea surface temperatures—the result of manmade global warming—even though, as Roger Pielke, Jr. reminds us, we’re in the longest drought of Category 3, 4 and 5 storms on record.
So let’s take a look at current sea surface temperature anomalies for the Main Development Region (10N-20N, 80W-20W) and the Gulf of Mexico (21N-31N, 98W-81W) as we head into the early part of the season. And we’ll look at data over three time periods: (1) since January 1854, using NOAA’s Extended Reconstructed Sea Surface Temperature data (ERSST.v3b), (2) since November 1981, with NOAA’s monthly satellite-enhanced Optimum Interpolation Sea Surface Temperature data (Reynolds OI.v2) and (3) since January 1990, using the weekly Reynolds OI.v2 data. To highlight the current values, they are shown as horizontal red lines in each graph. Anomalies are referenced to the period of 1971-2000, which NOAA uses for their Reynolds OI.v2 data.
LONG-TERM SEA SURFACE TEMPERATURE RECONSTRUCTION
The NOAA ERSST.v3b data start in January 1854. Keep in mind, though, that there is less source data for the early periods. For the Main Development Region, April 2014 sea surface temperature anomalies are only 0.11 deg C above the 1971-2000 reference temperatures, while the sea surface temperatures in the Gulf of Mexico are just below “normal”, according to the reconstruction. See Figures 1 and 2.
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MONTHLY SATELLITE-ENHANCED DATA
The satellite-enhanced Reynolds OI.v2 sea surface temperature data has a much higher resolution than the ERSST.v3b reconstruction, the latter of which only uses data from buoys and ship inlets. As shown in Figures 3 and 4, the sea surface temperature anomalies for the Main Development Region are effectively “zero”, while in the Gulf of Mexico they’re about -0.1 deg C…that is they’re below the 1971-2000 average.
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WEEKLY SATELLITE-ENHANCED DATA
The weekly satellite-enhanced Reynolds OI.v2 data had showed a slight rebound in recent weeks for the Main Development Region but dropped again last week, while in the Gulf, sea surface temperatures continue to cool. See Figure 5 and 6.
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If and when we have a hurricane or two develop in the months to come, I’ll update the graphs. You’ll likely want some up-to-date graphs to counter the alarmist nonsense. And I’ll include the data for the extratropical coastal waters of the east coast, Sandy’s storm track, since people find it of interest. (See the posts here and here.)