936 FXUS62 KJAX 010152 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 952 PM EDT Wed Mar 31 2021 ...STRONG STORM POTENTIAL HAS WEAKENED... .UPDATE... An outflow boundary raced southward ahead of pre-frontal convection across SE GA and the Suwannee River Valley which further stabilized a marginally unstable airmass this evening, resulting in limited strong storm potential. Convection will continue to decrease in intensity and coverage tonight as it settles ESE ahead of the surface cold front. There is a low chance of a thunderstorm edging inland from the GOMEX near Gilchrist/Alachua/Marion counties before sunrise tomorrow morning with westerly flow advecting shallow instability inland just ahead of actual surface front, but this potential is quite low and trended with just showers after 2 am for now for all zone. The cold front will press south of the area through 12-14z tomorrow morning, trailed by clearing skies, gusty WNW winds and a cooler, drier airmass with highs in the low 60s to near 70 Thursday. && .MARINE... Winds will increase tonight to Small Craft Exercise Caution trailing the cold front passage with widespread Small Craft Advisory conditions for all legs starting tomorrow morning. Isolated evening thunderstorms will continue to drift east over the outer FL waters south of St. Augustine through midnight, with mainly gusty showers associated with the cold front overnight. Rip Currents: Moderate rip current risk. && .PREV DISCUSSION [722 PM EDT]... .NEAR TERM [Through Tonight]... West coast sea breeze pushed scattered showers and storms eastward across northeast Florida earlier this afternoon and is now interacting with the east coast sea breeze. South-southwest flow will keep showers and isolated thunderstorm over the I-95 corridor and nearshore waters into this evening. For tonight, attention will turn to approaching cold front from the Northwest which will trigger a squall line across SW Georgia that will show some weakening as it pushes into inland SE GA just after sunset. The risk for isolated strong to severe storms with damaging winds still possible through midnight mainly for areas northwest of Alma before the rest of the pre-frontal squall line and trailing cold front push through the remainder of the area with scattered showers during the overnight hours. Will be quite a range of temps by sunrise tomorrow morning with 60s along and just south of the frontal boundary near the NE FL coast while most areas inland just behind the front will fall into the 50s, and even some cooler upper 40s possible after sunrise across extreme inland SE GA. Breezy Northwest winds at 15 to 20 mph will pick up behind the frontal passage through the night with gusts to 30 mph possible at times as cold air advection increases. .SHORT TERM [Thursday Through Friday Night]... Strong cold front will exit the area tomorrow morning with some lingering showers possible across north-central FL and northeast FL coastal zones. Strong high pressure builds in from the northwest tightening the gradient across the area. Breezy northwesterly winds develop in the wake of the frontal passage with sustained winds 15-20 mph and gusts up to 30 mph possible. Breezy northerly winds and cold air advection will cause low temperatures Thursday night to drop into the mid 30s across inland southeast GA to the mid 40s along the coast and wind chills in the 30s. Winds begin to weaken on Friday as high pressure shifts southeast over the region. Lighter winds Friday night will allow for potential frost development over inland southeast GA and Suwannee Valley. .LONG TERM [Saturday Through Tuesday]... Surface high pressure over the Carolinas Saturday morning will slowly shift southward through Tuesday and will be the dominant weather feature during this period. A stream of shortwaves will progress across Gulf coast states this weekend into early next week. Models keep the area dry through the period and so the shortwaves will only bring an increase in cloud cover. Below normal temperatures on Saturday warm to above normal by early next week. .AVIATION... [Through 00Z Friday] Breezy SSW winds early this evening will relax into the 7-10 kt range after sunset with only VCSH for coastal terminals over the next hour or two due to lingering sea breeze convection. A pre- frontal squall line edging southward across GA this evening is expected to weaken in intensity through midnight as precipitation settles southward approaching the local terminals. Gusty winds, brief heavy showers and MVFR restrictions are likely as convection presses across the terminals from NW to SE through 12z. Best potential for IFR restrictions will be near GNV after 08z where low stratus may advect inland along the leading edge of the cold front. Low ceilings improve to VFR 12-14z as WNW winds increase to 13-16 kts with gusts near 25 kts by mid-morning. Skies becoming SKC into the afternoon with a continuation of gusty WNW winds as a much colder airmass settles across the region. .FIRE WEATHER... A chance of showers and slight chance of thunderstorms over northeast Florida this afternoon with the sea breeze, then potential for a line of showers and thunderstorms moving into southeast Georgia this evening due to the cold front, and some strong storms will be possible in southeast Georgia. The cold front will move southeast across the area tonight and southeast of the region tomorrow morning. Relative humidities will fall to critical levels tomorrow and Friday. Gusty northwesterly winds develop tomorrow leading to potential elevated fire danger for parts of southeast Georgia and northeast Florida. Red flag warnings are not anticipated at this time due to elevated surface moisture. && .PRELIMINARY POINT TEMPS/POPS... AMG 51 63 35 58 34 / 100 0 0 0 0 SSI 55 65 41 57 42 / 70 10 0 0 0 JAX 56 67 39 59 38 / 40 20 0 0 0 SGJ 60 69 45 57 46 / 30 30 0 0 0 GNV 58 68 40 62 39 / 40 20 0 0 0 OCF 61 71 40 65 39 / 30 30 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...Small Craft Advisory from 10 AM Thursday to 2 PM EDT Friday for Coastal waters from St. Augustine to Flagler Beach FL out 20 NM-Waters from St. Augustine to Flagler Beach FL from 20 to 60 NM. Small Craft Advisory from 6 AM Thursday to 2 PM EDT Friday for Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM-Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM-Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM-Waters from Fernandina Beach to St. Augustine FL from 20 to 60 NM. &&