


Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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452 FXUS62 KJAX 160745 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 345 AM EDT Fri May 16 2025 ...NEAR RECORD HEAT CONTINUES THROUGH MIDWEEK NEXT WEEK... ...AREAS OF LOCALLY DENSE FOG POSSIBLE INLAND DURING THE EARLY MORNING HOURS THROUGH THE WEEKEND... ...NEXT COLD FRONTAL PASSAGE ON LATE WEDNESDAY OR THURSDAY... For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf .SYNOPSIS... Issued at 344 AM EDT Fri May 16 2025 Overnight surface analysis depicts Atlantic ridging extending its axis westward across the FL peninsula through the eastern Gulf. Meanwhile, a cold front extends from the Great Lakes southwestward through the Arklatex region. Aloft...ridging over the Gulf continues to expand northeastward towards our region. Otherwise, deep troughing over the Dakotas and Upper Midwest was progressing slowly eastward. Latest GOES East derived Total Precipitable Water imagery indicates that PWATs remain mostly in the 1 - 1.25 inch range, with slightly higher amounts around 1.4 inches located near the Altamaha River in southeast GA. Mostly thin cirrus cloudiness continues to spill over the top of the Gulf ridge that was building towards our area, with latest nighttime infrared satellite imagery showing low stratus cloud cover developing along and north of the Interstate 10 corridor in the Suwannee Valley. West-southwesterly winds remain sustained at 5-10 mph at most locations as of 07Z, which was keeping temperatures mainly in the upper 60s and lower 70s, with dewpoints generally in the mid to upper 60s. && .NEAR TERM... (Today and Tonight) Issued at 344 AM EDT Fri May 16 2025 Low stratus clouds and some potential for patchy to areas of fog will expand across the Suwannee Valley and portions of inland southeast GA through the predawn and early morning hours, with this low cloud cover likely reaching the U.S. Highway 301 corridor towards sunrise. Lower clouds should remain west of the I-95 corridor this morning, with mixing after sunrise likely allowing these lower ceilings to lift by mid-morning at inland locations. Periods of mostly thin cirrus will continue to spill overtop of the ridge and across our area through tonight. Otherwise, west- southwesterly low level flow will delay the development of the Atlantic sea breeze boundary to the early to mid afternoon hours at coastal locations. A dry and increasingly subsident atmosphere will allow for dewpoints to potentially fall to around 60 at inland locations this afternoon as filtered sunshine allows temperatures to soar to the mid and upper 90s at inland locations. These values will challenge daily record high temperatures at our designated climate sites (see "Climate" section below for details). This dry air mass will keep maximum heat index values in the upper 90s to around 100, with coastal locations more likely to experience "feels-like" temperatures near the century mark as the afternoon sea breeze moves slowly inland, bumping coastal dewpoints back to the upper 60s to around 70 by the mid to late afternoon. This sea breeze will struggle to reach the I-95 corridor during the late afternoon, and its delayed development will yield highs in the lower 90s all the way to area beaches during the early to mid afternoon hours before an onshore breeze drops temperatures back to the upper 80s before sunset. Another round of low stratus and potentially some fog development is expected across the Suwannee Valley and portions of inland southeast GA after midnight, with some potential for eastward expansion of these low stratus ceilings and fog towards sunrise. Light westerly low level winds will otherwise prevail overnight, with lows only falling to the upper 60s inland and around 70 at coastal locations. && .SHORT TERM... (Saturday through Sunday night) Issued at 344 AM EDT Fri May 16 2025 High pressure will be centered to the southeast Saturday, with ridging extending west across southern FL. A cold front will drop into central GA Saturday afternoon. This pattern will then linger through Sunday night. The real question this period will be whether the front sinks far enough to be a focus for convection into SE GA. A few weak upper waves pass along the frontal zone during the period, which could cause the boundary to waiver a bit from north to south, otherwise there is not much support to push boundary into forecast area. So, at this point precipitation chances will be kept on the low side this period over SE GA, and NE FL will be kept dry. Temperatures will remain above seasonal averages throughout this period. With dewpoints largely in the 60s throughout this time frame, heat will not make it to advisory levels. With the prevailing flow from the west southwest between the ridge and the front, the heat will make it all the way to the beaches, with little, if any afternoon push inland of the east coast sea breeze. && .LONG TERM... (Monday through Thursday) Issued at 344 AM EDT Fri May 16 2025 The high pressure ridge will lift to the north into central FL Monday into Tuesday, with frontal boundary also moving further to the north. A ridge will be in place at 500mb. Subsidence under these two ridges and moisture still on the low side will provide dry weather for the start of the week. The ridge will move away to the southeast Tuesday night, as an upper trough digs into the southeastern US, and a cold front moves into southeastern US. Long term models have timing differences in the cold frontal passage, but in general looking at the Wednesday afternoon to Thursday afternoon time frame. Too early to determine potential strength of storms on the frontal passage, but indications are that there will be a fairly significant thermal boundary with it, suggesting it could be a strong passage. Temperatures will continue above average throughout this period. Thursday would start a trend toward lower readings. && .AVIATION... (06Z TAFS) Issued at 153 AM EDT Fri May 16 2025 VFR conditions will prevail at the regional terminals through at least 08Z. Low stratus ceilings and fog are expected to advect across the Suwannee Valley towards the GNV and VQQ terminals after 08Z, with enough confidence in this scenario to indicate prevailing MVFR visibilities at VQQ towards 09Z and at GNV towards 11Z. We left TEMPO groups for LIFR conditions at VQQ through around 12Z and for IFR conditions at GNV through around 13Z. Fog and low stratus could approach JAX after sunrise, but confidence was too low to indicate sub-VFR conditions at this time. Otherwise, VFR conditions will then prevail at the regional terminals by 14Z. West-southwesterly surface winds will remain sustained around 5 knots at the inland terminals overnight and 5-10 knots at the SSI and SGJ coastal terminals. The Atlantic sea breeze boundary will develop near the coastal terminals towards 18Z, with surface winds shifting to southeasterly at SGJ and south-southeasterly at SSI, where sustained speeds will increase to around 10 knots. The sea breeze may push inland to CRG towards 22Z, where winds will become south-southeasterly briefly before sunset. West-southwesterly surface winds will otherwise increase to around 10 knots by 19Z at the rest of the inland terminals, followed by speeds diminishing to around 5 knots by 06Z Saturday. && .MARINE... Issued at 344 AM EDT Fri May 16 2025 Atlantic high pressure will continue to extend its axis across the Florida peninsula through the weekend and early next week, keeping a prevailing offshore wind flow in place across our local waters. The afternoon sea breeze will shift winds to south and southeasterly for the near shore waters through around sunset, with winds shifting to southerly during the evening hours. Seas of 2 to 4 feet will prevail both near shore and offshore during the next several days. A weakening frontal boundary will enter the southeastern states late this weekend, but this front will stall to the north of the Georgia waters. An isolated late afternoon or evening thunderstorm is possible over the Georgia waters on Sunday. The next significant frontal boundary will move across our local waters by late Wednesday or Thursday, possibly accompanied by widely scattered showers and thunderstorms. Rip Currents: Prevailing offshore winds and low surf heights should keep the risk low through at least midweek next week. Afternoon sea breezes will increase surf heights somewhat, but a weak easterly ocean swell will not raise the risk appreciably. && .FIRE WEATHER... Issued at 344 AM EDT Fri May 16 2025 A dry and increasingly hot air mass will result in minimum relative humidity values falling to the 30-35 percent range at most locations today and again on Saturday. Breezy westerly transport winds will create good daytime dispersion values this afternoon. Westerly transport winds will strengthen even further on Saturday and will combine with elevated mixing heights to create high to very high daytime dispersion values on Saturday and Sunday. The Atlantic sea breeze should remain pinned to the east of I-95 through the mid to late afternoon hours today and again on Saturday, with this boundary expected to push further inland on Sunday afternoon. && .CLIMATE... Issued at 344 AM EDT Fri May 16 2025 Daily Record High Temperatures through Tuesday at our designated climate sites: Fri 5/16 Sat 5/17 Sun 5/18 Mon 5/19 Tues 5/20 -------------------------------------------------- Jacksonville 96/1995 96/1995 96/1899 97/1960 99/1962 Gainesville 98/1896 96/1915 97/1930 99/1899 97/1938 Alma, GA 95/1990 94/2001 95/2001 97/1960 99/1962 Craig Airport 94/1994 93/2001 93/2001 92/2006 97/2006 && .PRELIMINARY POINT TEMPS/POPS... AMG 93 69 92 70 / 0 0 0 0 SSI 92 71 92 74 / 0 0 0 0 JAX 97 68 96 69 / 0 0 0 0 SGJ 93 70 96 69 / 0 0 0 0 GNV 94 67 94 67 / 0 0 0 0 OCF 92 68 93 67 / 0 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$