Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
344 FXUS62 KJAX 232301 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 701 PM EDT Thu Jul 23 2026 .KEY MESSAGES... For the latest NE FL and SE GA Daily Key Messages please visit: https:/www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf - Seasonably Hot & Humid through Friday Heat Index 102 - 108. Heat Advisories Possible this Weekend and Next Week for Portions of Our Area - Moderate Rip Current Risk Continues at Area Beaches - Only Isolated Afternoon & Evening Thunderstorms through Friday. Main Impact Area this Afternoon & Evening: I-75 Corridor & Okefenokee Swamp - Scattered to Numerous Afternoon & Evening TStorms this Weekend. Strong Storms Possible Late Each Afternoon Along the I-95 Corridor && .NEAR TERM /UNTIL 7 AM FRIDAY MORNING/... Main Highlights through Tonight: - Isolated to Widely Scattered Thunderstorms Possible Late this Afternoon and Evening along the I-75 Corridor, Possibly Extending Northward through the Okefenokee Swamp. Afternoon surface analysis depicts Atlantic high pressure centered well to the northeast of Bermuda that was extending its axis southwestward across our region. Meanwhile, weakening Tropical Storm Bertha (1004 millibars) was moving westward across coastal southwestern Louisiana towards the upper Texas coast. Otherwise, a frontal boundary was positioned from the Carolinas southwestward through the lower Mississippi Valley and eastern portions of Texas. Aloft..."heat wave" ridging centered over northern and central Texas has expanded its axis southeastward across our region, while a potent shortwave trough pivoting across New England has dug a longwave trough southward through the Ohio Valley and the Mid- Atlantic states. Latest GOES-East derived Total Precipitable Water imagery indicates that the Saharan Air Layer that was in place across much of our area on Wednesday has retreated westward, with PWATs near or below 1.5 inches now confined to inland southeast GA and western portions of the Suwannee Valley. PWATs elsewhere were still a little below late July climatology, with values generally in the 1.6 - 1.8 inch range. A cumulus field developed late this morning across these locations to the east of the SAL, with fair skies remaining across inland southeast GA early this afternoon. Temperatures at 17Z were in the low to mid 90s at most inland locations, while an onshore breeze was keeping coastal locations in the upper 80s to around 90. Dewpoints ranged from the low to mid 70s inland and the upper 70s to around 80 at coastal locations. Just enough moisture will be in place for isolated to widely scattered convection to develop along the inland moving Gulf sea breeze boundary along the I-75 corridor late this afternoon, with activity potentially extending northward through the Suwannee Valley and possibly the Okefenokee Swamp in southeast GA towards sunset as the Atlantic sea breeze boundary collides with the Gulf sea breeze. Locations east of the U.S. Highway 301 corridor in southeast GA, northeast and north central FL should remain unseasonably dry through at least early Friday afternoon as a largely subsident air mass remains in place beneath the low and mid level ridge axis across our region. While an isolated, brief shower could develop west of I-95 along the inland moving Atlantic sea breeze boundary late this afternoon, measurable rain chances are less than 20% for locations along and east of U.S. Highway 301. Isolated to widely scattered convection that manages to develop across north central FL, the Suwannee Valley, and the Okefenokee Swamp in southeast GA could linger into the mid-evening hours as activity drifts westward. An unseasonably low coverage of afternoon convection here in late July will allow inland temperatures to peak in the mid to upper 90s, while breezy onshore winds behind the inland moving Atlantic sea breeze boundary keep coastal highs closer to 90. Dewpoints mixing down to the upper 60s and lower 70s at inland locations should keep heat index values just below Heat Advisory criteria through late this afternoon, with peak readings mostly in the 103-107 degree range. Thin cirrus cloud cover will filter southward across our region tonight, with lows only falling to the mid 70s inland and the upper 70s to around 80 at coastal locations. && .SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Main Highlights This Period: - Scattered to Numerous Afternoon Saturday - Potential heat advisory conditions Saturday A quasi-stalled frontal boundary will be north of the area on Friday. As overall winds remain light on Friday, both the Gulf and Atlantic sea breeze will be able to push inland during the afternoon hours, with mergers likely along inland locations near the I-75 corridor. Though limiting amount of moisture aloft will keep shower and storms chances Low for most of the area, but could see isolated showers and storms along across SE GA as moisture levels will be a bit higher compared to NE FL. Temperatures will continue to remain in the mid to upper 90s area-wide, with the `cooler` locations along the east coast with the easterly winds providing some relief from the heat. Heat index values still currently look to fall just under Heat Advisory criteria, but will reassess if an Advisory is needed with the next forecast package. The frontal boundary will begin to push south towards SE GA late Friday/early Saturday as the trough over the mid Atlantic states digs southward. On Saturday, west-northwest flow develops ahead of the front, which will keep the Atlantic sea breeze pinned along the coast, but allow the Gulf breeze to push well inland. With PWATs expected to rise to near or above 2", scattered showers along the Gulf breeze at it pushes inland, with scattered to numerous showers and storms developing as the Gulf breeze merges with the Atlantic sea breeze during the afternoon to evening hours. Temperatures will rise to the upper 90s for locations west of the I-95 corridor, with temperatures in the lower 90s along the coast. With the warmer temperatures and higher moisture, inland Heat index values currently are trending to rise to the 106 to 110 range, likely bringing the need for Heat Advisories for Saturday. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Main Highlights This Period: - Increasing Chances for Afternoon and Evening Thunderstorms Late this Weekend and Early Next Week - Potential Heat Advisory Conditions Sunday into Next Week Overall flow will continue to be from the west on Sunday, which will again continue to keep the Atlantic sea breeze pinned along the coast and Gulf breeze to push well inland. With the front dipping further south towards NE FL, much of the shower and storm chances will shift over NE FL and coastal locations as showers and storms develop with the inland push of the Gulf breeze and mergers with the Atlantic sea breeze near the I-95 corridor. Showers and storms will once again be possible Monday afternoon, with higher chances over NE FL and north central FL as the front pushes through. Precipitation chances remain into midweek, but with only scattered chances past Monday. Highs will be above normal as temperatures will be in the mid to upper 90s Sunday into midweek for inland locations, with mid 90s along the coast. Heat Advisories may be necessary for Sunday and into midweek as Heat index values rise to close to or above heat advisory criteria with as values in the 106F to 110F. && .AVIATION /00Z FRIDAY THROUGH 00Z SATURDAY/... Mainly VFR conditions will prevail at the regional terminals through the period. A few showers may pass in the vicinity of GNV this evening but all convection should end by 4Z. Periods of MVFR visibilities will be possible at VQQ in the pre-dawn hours. East- southeasterly surface winds around 5-10 kts this evening will become light and variable to calm overnight. East-southeasterly winds develop again after 15Z. && .MARINE... Atlantic high pressure will continue to extend its axis across the southeastern states through Friday, creating prevailing onshore winds across our local waters. Meanwhile, a stationary frontal boundary extending from the Mid-Atlantic states into the lower Mississippi Valley will begin to drift southward towards the Georgia waters this weekend, pushing the axis of Atlantic high pressure southward. This change in the weather pattern will create a prevailing offshore wind flow this weekend and for much of next week, with scattered to numerous afternoon and evening thunderstorms expected across our local waters each day. A few stronger storms will be possible during the late afternoon hours, with briefly strong wind gusts, frequent lightning strikes, and torrential downpours possible. Rip Currents: Breezy conditions expected to redevelop towards noon on Friday at area beaches that could bump surf heights up to 2-3 feet at the northeast FL beaches, possibly creating a more solid moderate risk on Friday afternoon. Prevailing winds will shift to offshore this weekend, possibly lowering the risk to low at the southeast GA beaches. Onshore winds developing behind the inland moving sea breeze during the early to mid afternoon hours this weekend could keep a lower end moderate risk in place at the northeast FL beaches. && .FIRE WEATHER... - High Daytime Dispersion Values Inland Sunday Light and variable winds will develop late this afternoon and remain light through the overnight hours. A frontal boundary to the north of the area will sink southwards slowly Friday into the weekend with increasing chances for thunderstorms. Fair to Good dispersions develop on Friday and Saturday. Increasing transport winds will support high daytime dispersions across inland areas on Sunday. Min RH values will be in the 35% to 40% on Friday afternoon with lower RH values over inland locations. Come Saturday min RHs improve as moisture increases across the area. With the increase moisture, showers and storms will be more likely during the afternoon hours as the Gulf breeze pushes well inland, will the overall flow predominantly from the west this weekend. Fog Potential and Other Remarks: Significant fog development is not expected for the next several nights. && .PRELIMINARY POINT TEMPS/POPS... AMG 75 97 75 95 / 10 20 20 50 SSI 78 93 79 95 / 0 0 0 50 JAX 75 96 76 98 / 10 0 0 60 SGJ 76 92 75 95 / 0 0 0 20 GNV 74 96 74 97 / 20 10 0 40 OCF 74 96 75 97 / 20 0 0 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. MARINE...None. && $$