Davenport, Florida

... Red flag warning remains in effect from 1 PM this afternoon to
7 PM EDT this evening...

A red flag warning remains in effect from 1 PM this afternoon to
7 PM EDT this evening.

High pressure will build into the region through Saturday. Dry
air associated with the high will allow humidity values to drop
below 35 percent for four or more hours Saturday afternoon across
inland areas... with values bottoming out in the 27 to 30 percent
range.

Precautionary/preparedness actions...

A red flag warning is issued when very favorable conditions for
the spread of wildfire are occurring now... or will occur within
24 hours.

Please advise the appropriate officials or fire crews in the
field.

... One of the coldest astronomical Winters since records began...

For much of the astronomical winter (dec 21-Mar 19) the region
experienced much below normal temperatures. These cool readings
have been attributed to the Arctic oscillation (ao)... which has
been shown to have a big influence on temperatures across the
eastern two-thirds of the United States during the winter months.
For much of late December into March the ao was in the negative
phase which means there is higher-than-normal pressure over the
polar region and lower-than-normal pressure at about 45 degrees
north latitude. When this occurs cold air tends to plunge
southward into the midwestern/eastern United States... which we
did see on numerous occasions during the winter as cold fronts
swept southward across Florida at least once if not twice each
week.

Astronomical winter can vary by a day at the beginning (dec 21 or
Dec 22) and end (mar 19 or Mar 20)... but overall generally lasts
about 89 days. If we take a look at the average temperature
this year during this time period we see that west central and
southwest Florida experienced readings some 5 to 8 degrees below
normal which was the coldest or second coldest since records
began at most locations.

The tables below list the top ten coldest astronomical Winters at
some sites across the region... including the average astronomical
winter temperature.


Top 10 coldest astronomical top 10 coldest astronomical
Winters at inverness: Winters at Brooksville chin hill:

1 55.0 in 1996 *1 55.3 in 2010*
2 56.0 in 1958 2 56.6 in 1920
3 56.1 in 2003 2 56.6 in 1901
4 56.3 in 1995 4 56.9 in 1940
5 56.9 in 1987 5 57.1 in 1931
6 57.1 in 2005 6 57.3 in 1926
7 57.2 in 1986 7 57.8 in 1996
8 57.4 in 2001 7 57.8 in 1900
9 57.5 in 1968 7 57.8 in 1893
10 57.7 in 2006 10 58.6 in 2001
10 57.7 in 1980

A few days in March were not
available at the time of
publishing... but the average
will most likely end up
around 55 degrees... or in
first or second place.

Normal winter at invf1 = 59.7 normal winter at brof1 = 62.3
records began 1948 records began 1892

   -----------------------------------------------------

Top 10 coldest astronomical top 10 coldest astronomical
Winters at St. Leo: Winters at plant city:

1 54.6 in 1931 *1 56.1 in 2010*
*2 54.8 in 2010* 2 56.6 in 1940
3 55.9 in 1978 3 58.2 in 1902
4 56.4 in 1940 4 58.6 in 1958
5 57.6 in 1958 4 58.6 in 1936
6 57.9 in 1969 6 58.9 in 1901
7 58.2 in 1977 7 59.1 in 1977
8 58.3 in 1968 8 59.3 in 1996
9 58.4 in 1926 9 59.7 in 1969
10 58.5 in 1981 10 60.0 in 1910
10 58.5 in 1970

Normal winter at stlf1 = 63.0 normal winter at plcf1 = 63.5
records began 1895 records began 1892

   -----------------------------------------------------

Top 10 coldest astronomical top 10 coldest astronomical
Winters at tampa: Winters at Sarasota-bradenton:

1 55.6 in 1978 1 55.8 in 1931
*2 56.2 in 2010* 2 56.2 in 1940
3 56.9 in 1969 3 56.3 in 1917
4 57.0 in 1940 *4 56.6 in 2010*
5 57.2 in 1958 5 57.1 in 1958
6 57.6 in 1968 6 57.4 in 1969
7 57.8 in 1977 7 57.9 in 1926
8 58.0 in 1970 8 58.0 in 1915
9 58.3 in 1931 9 58.1 in 1920
10 58.7 in 1902 10 58.3 in 1941

Normal winter at tpa = 63.7 normal winter at srq = 63.9
records began 1890 records began 1911

   -----------------------------------------------------

Top 10 coldest astronomical top 10 coldest astronomical
Winters at St petersburg: Winters at Avon park:

*1 56.9 in 2010* *1 54.8 in 2010*
2 57.7 in 1940 2 56.3 in 1978
3 58.4 in 1978 3 56.4 in 1981
4 58.5 in 1958 4 57.9 in 1977
5 59.0 in 1996 5 58.8 in 1996
6 59.5 in 1981 6 58.9 in 1940
7 59.9 in 1931 7 59.2 in 1931
8 60.1 in 1977 8 59.5 in 1980
8 60.6 in 1969 9 59.8 in 1984
10 60.8 in 1915 9 59.8 in 1979

Normal winter at spg = 64.0 normal winter at avpf1 = 63.1
records began 1914 records began 1901

   -----------------------------------------------------

Top 10 coldest astronomical top 10 coldest astronomical
Winters at Punta gorda: Winters at fort myers:

1 58.7 in 1978 1 59.3 in 1978
*2 58.9 in 2010* *2 59.9 in 2010*
3 60.5 in 1981 3 60.2 in 1958
4 60.7 in 1970 4 60.9 in 1970
5 60.8 in 1969 5 61.0 in 1977
6 61.6 in 1968 5 61.0 in 1940
7 61.7 in 1996 7 61.8 in 1981
8 62.6 in 1979 8 62.0 in 1969
9 63.1 in 1984 8 62.0 in 1941
10 63.5 in 1995 10 62.8 in 1968

Normal winter at pgd = 65.6 normal winter at fmy = 67.0
records began 1965 records began 1902



For more local climate information... please visit our web Page at
http://weather.Gov/tampabay and click on the "local" link under the
climate subsection on the left side of the Page.

For more details about the January 2010 cold spell and the Arctic
oscillation check our winter 2010 Suncoast weather observer at the
following link:

Http://www.Srh.NOAA.Gov/images/tbw/topnews/pdf/2010winternewsletter.Pdf