...NUMEROUS SHOWERS AND THUNDERSTORMS TODAY...

Plan your trip Local Radar Detailed Forecast

Today: Mostly cloudy. A chance of showers and thunderstorms in the morning, then showers and thunderstorms likely in the afternoon. Some thunderstorms may produce heavy rainfall. Highs 89 to 93. West winds 5 to 10 mph. Chance of rain 70 %. Heat index readings 101 to 105.

Tonight: Partly cloudy. A chance of showers and thunderstorms in the evening, then a slight chance of showers after midnight. Lows in the mid 70s. Northwest winds 5 mph. Chance of rain 40 %.

Numerous showers and thunderstorms are expected today. storms will first develop over northeast Florida and move southeast at 5 to 10 mph. Additional showers and storms are expected to develop across southeast Georgia by the afternoon. Locally heavy rainfall is likely in some storms with rainfall rates of 2 to 3 inches per hour. In addition, gusty winds and excessive lightning are expected with the tronger storms.

Warm and humid conditions will continue to produce heat index values near 105 degrees today.

Forecast Details: surface data shows broad trough from central Alabama to central Georgia to southern South Carolina to a low offshore near 31n76w. Low level flow is west to northwest over the area. Dewpoints are very high, mostly in the upper 70s over the County Warning Area. Present radar loops show scattered to numerous showers and storms over Marion County where occasional heavy rainfall is occurring.

JAX sounding shows precipitable water of 2.42 inches and weak shear. Modified sounding yields cape values of 3500-4000 j/kg with little in the way of support of strong wet down-bursts. However, pockets of dry air noted in RUC fields over southeast Georgia and near the coast could support strong downburst winds with Delta thetae values around 20-25. Main threat to convection today will be heavy rainfall due to the slow storm motion near 5 knots and abundant moisture. This heavy rain threat looks more probable near the eastern Florida zones and interior southeast Georgia.   Models show the aforementioned trough axis will drift southward today while some middle level energy approaches from the northwest. Expect most activity to be over northeast Florida today with probability of precipitation nudged up to near 70% with southeast Georgia probability of precipitation maintained near 50-60%. Temperatures today will held in check by cloud cover and precipitation but still anticipate most sites to hit 90, continuing the hot streak of temperatures this Summer.   Today's Pollen Levels: 5.7 Medium  (on a scale to 12); Predominate Pollen: Ragweed, Grass and Chenopods.

For additional information visit the National Weather Service in Jacksonville website on the internet at http://www.srh.noaa.gov/jax/