AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 324 AM EST Thu Nov 21 2024 ...New NEAR TERM, SHORT TERM, LONG TERM, MARINE, FIRE WEATHER... ...COLDER, DRIER TODAY UNDER GUSTY NW WINDS... .NEAR TERM... Issued at 321 AM EST Thu Nov 21 2024 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf Dry air continues to fill in behind the front, leaving mostly sunny skies and cooler temperatures today. Winds will be breezy out of the northwest as pressure gradients tighten and daytime mixing develops throughout the day. Daytime high temperatures will only get into the low 60s over southeast Georgia and low to mid 60s over northeast Florida. Southeast Georgia could see some overnight lows in the upper 30s to low 40s with northeast Florida dipping into the low to mid 40s. && .SHORT TERM... (Friday through Saturday night) Issued at 321 AM EST Thu Nov 21 2024 Synopsis...Dry weather and below normal temperatures with potential inland frost each morning this weekend. Friday cold air advection continues with high temperatures only in the upper 50s across parts of SE GA to the mid 60s across north- central FL under continued gusty NW winds with gusts 25-30 mph as the local pressure gradient remains elevated between the surface high building eastward across the the western Gulf Coast states and a re-enforcing dry cold front moving offshore of the Carolinas. These highs are about about 8-12 degrees below normal for this time of year. Friday night, elevated winds continue as another surface trough moves offshore of the Carolinas. Cold air advection continues Friday night, with low temperatures falling into the 30s across mainly inland locales to the lower 40s toward the Atlantic coast. These 30 degree temperatures for NE FL Saturday morning will be the first 30s since March of 2024 (JAX and GNV both had lows in the 30s on 3/20/2024). With inland winds in the 5-10 mph range by daybreak Sat morning, wind chills will be the low to mid 30s for most locations. Given elevated Saturday morning around sunrise, frost formation is expected to be patchy in nature and only in wind sheltered areas. Saturday, high temperatures are expected to range in the 60s with less wind as the surface ridge builds farther east across the region, with the ridge centering over the local forecast area Saturday night. With near calm wind, clear skies and continued dry low level air in place, leaned on the cool side of guidance with lows in the mid 30s to possibly a few lower 30s for inland locations. Latest guidance suggests about a 20-30% of a brief inland freeze for our normally cooler inland locales Sunday morning including Folkston to Taylor. Sunday morning around daybreak will also be the better time period for possibly frost formation and continued to indicated `patchy` frost at this time in the official forecast. && .LONG TERM... (Sunday through Wednesday) Issued at 321 AM EST Thu Nov 21 2024 Synopsis...Continued dry with a warming trend ensuing early next week. Continued dry weather with a moderating trend in temperatures for the start of next week. Sunday, warmer WSW winds develop as the center of the surface high shifts offshore of the local Atlantic coast, with a ridge axis remaining stretched across the local area through Tuesday. Just above the surface, warmer SW flow develops, which will moderate temperatures back above normal values with highs in the 70s with a continuation of chilly nighttime lows in the upper 40s to 50s given the drier low level airmass in place allowing for good radiational cooling. Anticipate daily sea breezes Mon/Tue which will gradually return low level moisture, and increase late night and early morning fog potential. By Wednesday, the surface ridge begins to shift farther SSE as a frontal zone attempts to drift southward across SE GA, increasing cloudiness across the area but likely keeping rainfall still north of the area through at least mid-week given weak upper level pattern with only weak short wave troughs aloft. && .AVIATION... (06Z TAFS) Issued at 1203 AM EST Thu Nov 21 2024 Skies have cleared as dry air has filled in behind the passing front. VFR conditions will prevail with northwest flow of 10-15 kt, with some gusts of 20-25 kt through tonight. Wind gusts should subside temporarily by sunrise but, start up again by mid morning as daytime mixing develops. Winds will slow to 5-10 kt after sunset through the end of the TAF period. && .MARINE... Issued at 321 AM EST Thu Nov 21 2024 Small Craft Advisory levels are expected today for all area waters through Friday. This morning, gale force winds in the offshore waters north of St. Augustine will drop off shortly after sunrise. Strong northwesterly winds are forecast to continue along with increasing seas through Friday into Saturday morning. Winds will begin to drop off fairly quickly over the weekend. Rip Currents: Low risk of rip current at SE GA beaches through the weekend with NE FL beaches having a low to moderate risk through Friday dropping to low risk over the weekend. && .FIRE WEATHER... Issued at 321 AM EST Thu Nov 21 2024 Colder and drier under gusty WNW winds today trailing a cold front passage. Gusts of 25-30 mph will be possible at times as minimum humidity falls into the 25-30% range for most locations. High daytime dispersion is expected near the Altamaha River basin. Cooler high temperatures Friday and a slight increase in dew points will increase minimum afternoon humidity to 30-40% for most locations under continued gusty NW winds. Elevated fire danger is possible this afternoon for parts of SE GA where minimum RH may near 25%. Otherwise, elevated 1 hr fuel moisture and a low fire danger index limit fire danger concerns today. Conditions are not favorable for fog formation the next several nights. Patchy inland frost is possible Saturday and Sunday mornings - with Sunday morning being the better morning for frost potential. && .PRELIMINARY POINT TEMPS/POPS... AMG 61 38 57 35 / 0 0 0 0 SSI 62 45 60 41 / 0 0 0 0 JAX 64 42 63 38 / 0 0 0 0 SGJ 64 46 63 44 / 0 0 0 0 GNV 64 40 63 37 / 0 0 0 0 OCF 65 41 65 38 / 0 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...Small Craft Advisory until 9 PM EST Friday for AMZ450-452-454. Gale Warning until 8 AM EST this morning for AMZ470-472. Small Craft Advisory from 8 AM this morning to 7 AM EST Saturday for AMZ470-472. Small Craft Advisory until 7 AM EST Saturday for AMZ474. && $$