When does Autumn start? Defining seasons

20 09 2012

When does Autumn start? Defining seasons.

How dry has this September been?

19 09 2012

By Dale C. S. Destin

Antigua is currently experiencing a meteorological drought, which started in February of this year. Notwithstanding the active hurricane season, so far, September has been especially dry. The first half of the month only yielded 1.3 mm / 0.05 inch of rainfall at the V. C. Bird International Airport. This tied with September of 1986 for the lowest total at the Airport on record (1971-2012). Below normal rainfall was anticipated for the month so this does not come as a surprise. This sort of rainfall is consistent with a warm Pacific Ocean (El Nino) and a lukewarm/cold tropical north Atlantic (TNA) Ocean. The lowest total rainfall for the month of September on record at the Airport is 27.2 mm or 1.07 inches (1978, at the start of a strong El Nino and cold TNA), while the highest is 410.2mm or 16.15 inches (1995, during a moderate La Nina Episode and warm TNA). Thus, based on record, there has never been a sub-inch total for the month; only two other month has never experienced sub-inch rainfall – August and December. However, at the current rate, and based of the outlook, sub-inch rainfall is quite possible and would obviously make it a record dry September. Further, it would make the drought become severe.

It was Hell Today – Did You Notice?

4 09 2012

Dale C. S. Destin

Hot like hell! Today’s (4Sep, 2012) maximum temperature shattered the previous record for September. Today’s maximum of 34.3°C/93.7°F is now the highest on record (1971-2012) for September going well pass the month’s previous high of 33.5°C/92.3°F. It was also the second highest temperature on record for all months. Only August of 2005 had a higher maximum temperature with 34.9°C/94.8°F. In terms of how it actually felt to the human body; the heat index is a measure of this, and it peaked at 37°C/99°F. So although the maximum was 34.3°C/93.7°F, it really felt like 37°C/99°F. The heat index is a function of the temperature and the relative humidity. Today’s humidity was low; in the 40’s and 50’s; if it were higher, the heat index would have been higher and conditions would have been much more miserable even dangerous (http://en.wikipedia.org/wiki/Heat_index).

The conditions that led to today’s maximum temperature were light southerly wind and few low level clouds. These conditions were caused by the proximity of Tropical Storm Leslie between the Caribbean and Bermuda.

Conditions for the next four days are expected to be similar to today – light southerly winds and few low level clouds; hence, the rest of the week is expected to have above normal temperatures. These temperatures and resultant heat indices could reach dangerous levels. Residents should take precautions (http://www.epa.gov/heatisland/about/pdf/EHEguide_final.pdf)

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