NWS Miami Climatology Discussion on Dec/Jan/Feb Temps

[jinftl]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
205 PM EST FRI FEB 29 2008

CLIMATOLOGY...THE THREE WINTER MONTHS OF DECEMBER, JANUARY AND
FEBRUARY LIKELY WILL BE THE SECOND WARMEST WINTER FOR MIAMI SINCE
RECORDS ARE AVAILABLE. THE AVERAGE TEMPERATURE OF THOSE THREE MONTHS
WILL LIKELY BE AROUND 73.1 DEGREES. THE PERIOD OF RECORD FOR
MIAMI EXTENDS BACK TO 1895. THE ONLY WARMER WINTER WAS IN
1931-1932 WHEN THE AVERAGE TEMPERATURE OF THOSE THREE MONTHS WAS
73.4 DEGREES. FEBRUARY 2008 WILL ALSO LIKELY BE IN THE TOP THREE
OR FOUR WARMEST FEBRUARIES ON RECORD AT MIAMI.

http://www.crh.noaa.gov/product.php?site=NWS&issuedby=MFL&product=AFD&format=CI&version=1&glossary=1

[MiamiensisWx]

Although mean temperatures did not match the winters of 2005-2006 and 2006-2007 in Palm Beach County (West Palm Beach/PBI), that was primarily because of the period in January where the southern stream was active. The West Coast ridge and MJO variability lead to suppressed low heights across the Southeast, excluding extreme southern FL which was situated under the SE ridge. That led to several inland running lows and shortwaves through the Southeast. There was also the brief cold air intrusion with lows in the 30s across south Florida, but that has been the only real "event" this year. Overall, the persistent ridge has prevented below average temps, especially overnight. Low-level easterly flow returns quickly during this strong La Nina year. SW flow and decent clearings in cumulus fields lead to the recent warm above average highs. The surprise drainage winds during the recent "cool down" didn't reduce overnight lows, which still remained higher than originally progged. Most of the overnight "cool" events have underperformed.

Interestingly, temperatures have been exceeding climatological means during this month in Bermuda. One meteorologist on another board also noted the lack of extratropical storms in the vicinity because of the western Atlantic ridge.

[jinftl]

Many more overnight record high minimums were set than record daytime maximums in Miami and Fort Lauderdale this winter...and the reasons behind this are explained in your post...very interesting to learn the 'science' behind what I have seen in Daily Climate Tables.

Although mean temperatures did not match the winters of 2005-2006 and 2006-2007 in Palm Beach County (West Palm Beach/PBI), that was primarily because of the period in January where the southern stream was active. The West Coast ridge and MJO variability lead to suppressed low heights across the Southeast, excluding extreme southern FL which was situated under the SE ridge. That led to several inland running lows and shortwaves through the Southeast. There was also the brief cold air intrusion with lows in the 30s across south Florida, but that has been the only real "event" this year. Overall, the persistent ridge has prevented below average temps, especially overnight. Low-level easterly flow returns quickly during this strong La Nina year. SW flow and decent clearings in cumulus fields lead to the recent warm above average highs. The surprise drainage winds during the recent "cool down" didn't reduce overnight lows, which still remained higher than originally progged. Most of the overnight "cool" events have underperformed.

Interestingly, temperatures have been exceeding climatological means during this month in Bermuda. One meteorologist on another board also noted the lack of extratropical storms in the vicinity because of the western Atlantic ridge.

[MiamiensisWx]

Many more overnight record high minimums were set than record daytime maximums in Miami and Fort Lauderdale this winter...and the reasons behind this are explained in your post...very interesting to learn the 'science' behind what I have seen in Daily Climate Tables.

I was actually referring to the section of the report (see link) that states West Palm Beach did not receive mean temps as extreme as MIA-FLL, although we were above average. It is actually cooler here than the past two winters, though the differences are very slight. Generally, we have still seen above normal temps in the Palm Beach area. There has been a sharp temperature gradient between Palm Beach and MIA-FLL.

".CLIMATOLOGY...THE THREE WINTER MONTHS OF DECEMBER, JANUARY AND
FEBRUARY LIKELY WILL BE THE SECOND WARMEST WINTER FOR MIAMI SINCE
RECORDS ARE AVAILABLE. THE AVERAGE TEMPERATURE OF THOSE THREE MONTHS
WILL LIKELY BE AROUND 73.1 DEGREES. THE PERIOD OF RECORD FOR
MIAMI EXTENDS BACK TO 1895. THE ONLY WARMER WINTER WAS IN
1931-1932 WHEN THE AVERAGE TEMPERATURE OF THOSE THREE MONTHS WAS
73.4 DEGREES. FEBRUARY 2008 WILL ALSO LIKELY BE IN THE TOP THREE
OR FOUR WARMEST FEBRUARIES ON RECORD AT MIAMI. IT IS INTERESTING
THAT THE SAME STATISTIC DOES NOT APPEAR TO HOLD AT WEST PALM
BEACH, WHERE DJF AVERAGE TEMPERATURE FOR 2007-2008 IS NOT IN THE
TOP FIVE ALTHOUGH IT IS WARMER THAN NORMAL AND FEBRUARY 2008 IS
NOT IN THE TOP TEN WARMEST FEBRUARIES. RECORDS FOR WEST PALM GO
BACK TO 1888. FINAL STATISTICS AND SUMMARY WILL BE AVAILABLE
SOMETIME NEXT WEEK INCLUDING NAPLES AND FORT LAUDERDALE."

[jinftl]

Where has Naples been in terms of the gradient..more like Miami or West Palm, or neither?

Many more overnight record high minimums were set than record daytime maximums in Miami and Fort Lauderdale this winter...and the reasons behind this are explained in your post...very interesting to learn the 'science' behind what I have seen in Daily Climate Tables.

I was actually referring to the section of the report (see link) that states West Palm Beach did not receive mean temps as extreme as MIA-FLL, although we were above average. It is actually cooler here than the past two winters, though the differences are very slight. Generally, we have still seen above normal temps in the Palm Beach area. There has been a sharp temperature gradient between Palm Beach and MIA-FLL.

".CLIMATOLOGY...THE THREE WINTER MONTHS OF DECEMBER, JANUARY AND
FEBRUARY LIKELY WILL BE THE SECOND WARMEST WINTER FOR MIAMI SINCE
RECORDS ARE AVAILABLE. THE AVERAGE TEMPERATURE OF THOSE THREE MONTHS
WILL LIKELY BE AROUND 73.1 DEGREES. THE PERIOD OF RECORD FOR
MIAMI EXTENDS BACK TO 1895. THE ONLY WARMER WINTER WAS IN
1931-1932 WHEN THE AVERAGE TEMPERATURE OF THOSE THREE MONTHS WAS
73.4 DEGREES. FEBRUARY 2008 WILL ALSO LIKELY BE IN THE TOP THREE
OR FOUR WARMEST FEBRUARIES ON RECORD AT MIAMI. IT IS INTERESTING
THAT THE SAME STATISTIC DOES NOT APPEAR TO HOLD AT WEST PALM
BEACH, WHERE DJF AVERAGE TEMPERATURE FOR 2007-2008 IS NOT IN THE
TOP FIVE ALTHOUGH IT IS WARMER THAN NORMAL AND FEBRUARY 2008 IS
NOT IN THE TOP TEN WARMEST FEBRUARIES. RECORDS FOR WEST PALM GO
BACK TO 1888. FINAL STATISTICS AND SUMMARY WILL BE AVAILABLE
SOMETIME NEXT WEEK INCLUDING NAPLES AND FORT LAUDERDALE."

[MiamiensisWx]

Where has Naples been in terms of the sharp gradient?

Naples has actually featured near average temps... degree cooling days were above average due to the easterly flow.

000
CDUS42 KMFL 290836
CLIAPF

CLIMATE REPORT
NATIONAL WEATHER SERVICE MIAMI, FL
334 AM EST FRI FEB 29 2008


...................................

...THE NAPLES CLIMATE SUMMARY FOR FEBRUARY 28 2008...

CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1942 TO 2008


WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
NORMAL
..................................................................
TEMPERATURE (F)
YESTERDAY
MAXIMUM 66 359 PM 87 1997 77 -11 85
MINIMUM 46 716 AM 38 1980 56 -10 66
AVERAGE 56 67 -11

PRECIPITATION (IN)
YESTERDAY 0.00 2.00 1954 0.07 -0.07 0.00
MONTH TO DATE 1.52 2.17 -0.65 0.94
SINCE NOV 1 3.13 7.70 -4.57 1.82
SINCE JAN 1 2.21 4.18 -1.97 0.96

SNOWFALL (IN)
YESTERDAY 0.0
MONTH TO DATE 0.0
SINCE DEC 1 0.0
SINCE JUL 1 0.0
SNOW DEPTH 0

DEGREE DAYS
HEATING
YESTERDAY 9 2 7
MONTH TO DATE 14 82 -68
SINCE DEC 1 87 276 -189
SINCE JUL 1 93 285 -192

COOLING
YESTERDAY 0 4 -4
MONTH TO DATE 204 85 119
SINCE DEC 1 537 281 256
SINCE JAN 1 313 174 139
..................................................................


WIND (MPH)
HIGHEST WIND SPEED 16 HIGHEST WIND DIRECTION N (20)
HIGHEST GUST SPEED 20 HIGHEST GUST DIRECTION N (350)
AVERAGE WIND SPEED 7.4


SKY COVER
AVERAGE SKY COVER 0.0


WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.
NO SIGNIFICANT WEATHER WAS OBSERVED.


RELATIVE HUMIDITY (PERCENT)
HIGHEST 71
LOWEST 20
AVERAGE 46

..........................................................


THE NAPLES CLIMATE NORMALS FOR TODAY
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 77 84 1976
MINIMUM TEMPERATURE (F) 56 40 1980


SUNRISE AND SUNSET
FEBRUARY 29 2008......SUNRISE 651 AM EST SUNSET 628 PM EST
MARCH 1 2008.........SUNRISE 650 AM EST SUNSET 629 PM EST


- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.

http://www.weather.gov/climate/index.php?wfo=mfl

This does support our theories that the ridge has been more persistent, resulting in record minimums on the east coast and cooler temps on the west coast because of fewer SW flows. Remember that Naples is warmer in SW (instead of E) winds, especially for daytime highs. Note that dewpoints have been lower, too.

[HURAKAN]

It was a warm winter although at one point the temperature got down to 35F. Still, last weekend we went up to 90F.