Again, we’re posting this localized, farm specific weather information for south Florida growing areas from Gene McAvoy, County Extension Director, LaBelle, Florida, regarding tonight’s continuing cold weather (posted Sunday 2:30 p. m. 1/10/10)
A HARD FREEZE WATCH CONTINUES IN EFFECT FOR SOUTH FLORIDA AREAS TONIGHT AS VERY COLD AIR WILL CONTINUE IN PLACE OVERNIGHT. THE LOWS TONIGHT ARE EXPECTED TO FALL INTO THE LOWER TO MID 20S ACROSS GLADES…HENDRY…INLAND COLLIER FROM THE IMMOKALEE AREA SOUTH TO JUST NORTH OF U S 41 AND WESTERN PALM BEACH SOUTH OF LAKE OKEECHOBEE. FREEZING TEMPERATURES CAN BE EXPECTED ELSEWHERE.
PRECAUTIONARY/PREPAREDNESS ACTIONS…
A HARD FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE.
THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION.
Note that conditions today are such – low dewpoints and high wind – that use of over head irrigation or micro jets for freeze protection will do more harm than not using them.
Dry and windy conditions can result in wet bulb temperatures 5F to 6F degrees lower than air temperature. Therefore, wetted plant surfaces that experience evaporation would be 5F to 6F degrees cooler than air temperature.
See http://fawn.ifas.ufl.edu/tools/coldp/evaporative_cooling.php for more information