Showers and thunderstorms will continue to move into northeast Florida with the heaviest activity in the Suwannee Valley over southern Gilchrist and western Alachua counties. The showers decrease in intensity as they move into the coastal communities and coastal waters east of Ponte Vedra Beach. The showers are moving northeast at 20 miles an hour.

Today

Cooler aqnd cloudy. Showers likely and slight chance of thunderstorms in the morning, then chance of showers in the afternoon. Highs in the upper 50s. Northeast winds 5 to 10 mph. Chance of rain 60 %.

Tonight

Mostly cloudy with a 50 % chance of showers. Areas of fog after midnight. Lows around 50. Northeast winds 5 to 10 mph.

Forecast Details

Hard to believe strong to severe thunderstorms developed earlier tonight across northeast Florida, even following passage of surface cold front. In a nutshell, post-frontal air mass was quite shallow across northeast Florida and the 925 MB front basically stalled along a Gainesville to Jacksonville line. Myriad of lifting mechanisms came together,including lift along this 925 MB front, isentropic lift, upper level jet dynamics and passage of potent middle level shortwave trough. Deep southwesterly winds provided the fuel /moisture and instability and all the ingredients came together for strong/severe thunderstorms to develop.

Jet dynamics will weaken during the pre-dawn hours, and with mainly negative vorticity advection working into the middle levels of the atmosphere, thunderstorm activity will continue to decrease in both coverage and intensity, with mainly isolated thunderstorms expected.

The 925-850 MB Theta-E ridge axis will shift little through the morning hours and will continue to focus along a Gainesville to Jacksonville line. Will include highest /likely/ probability of precipitation across this area this morning. Numerical models indicate showers will begin to favor areas north of the I-10 corridor this afternoon, especially across southeast Georgia, as weather features to support isentropic lift begin to shift north. Will maintain north-south distribution of probability of precipitation for this afternoon, ranging from categorical probability of precipitation north of US Highway 82 to chance probability of precipitation south of the I-10 corridor.

Considerable cloudiness and northerly winds will keep temperatures below climatology, with afternoon highs ranging from upper 40s/lower 50s along and north of the I-10 corridor to lower 60s across our southern- most areas.

Inclement weather will continue through at least Friday with numerical models in good agreement that large scale forcing will continue to focus along and north of the I-10 corridor...as strong isentropic lift interacts with approach of middle level energy. A lifting warm front late Thursday night and into Friday will allow temperatures to warm into the 70s along and south of a Gainesville to St. Augustine line Friday afternoon.

Today's Pollen Levels: 6 Medium (on a scale to 12); Predominate Pollen: Cedar/Juniper.

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