000 FXUS62 KJAX 271227 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 827 AM EDT Mon Jun 27 2022 .AVIATION... [Through 12Z Tuesday] Showers and MVFR ceilings will overspread the SGJ and SSI coastal terminals through around 15Z. Otherwise, VFR conditions will prevail through at least 15Z at the regional terminals, with VFR conditions then expected to prevail at SSI and SGJ after 15Z. Showers and a few thunderstorms will develop along the inland moving Atlantic sea breeze boundary after 15Z, with potential impacts to the Duval County terminals through around 20Z. However, confidence was not high enough to indicate anything other than vicinity coverage at JAX, CRG and VQQ. Showers and thunderstorms are more likely after 20Z at GNV, where a PROB30 group was placed in the TAF for briefly gusty winds and MVFR conditions during heavier downpours through 00Z. VFR conditions should then prevail at GNV after 00Z. East-northeasterly winds sustained at 5-10 knots at SGJ will shift to easterly after 15Z and then southeasterly by 22Z, with speeds increasing to around 10 knots. Otherwise, light northeasterly surface winds at the rest of the terminals will gradually shift to easterly by 16Z and then southeasterly by 19Z, with speeds increasing to around 10 knots. && .PREV DISCUSSION [352 AM EDT]... .NEAR TERM [Through Tonight]... There will be increasing chances for showers this morning and thunderstorms this afternoon as an inverted trough sitting to the southeast over the Atlantic lifts west-northwestward across the area. As the trough lifts inland this morning, southeasterly flow will slowly advect moisture northward into NE FL, fueling isolated to scattered coastal showers across Flagler and St Johns counties. Morning shower activity at the coast will push inland across north-central FL with the trough axis through the early afternoon. An Atlantic sea breeze will develop in the wake of the trough and yield isolated to widely scattered convection along and west of I-95 in NE FL. Despite the influx of deeper moisture and resulting diurnal instability, a lingering layer of dry air and weak lapse rates in the mid levels will limit convective coverage and intensity this afternoon. Temperatures will be the hottest across inland SE GA and northern Suwannee Valley, reaching the mid 90s, while afternoon temps will be slightly lower across inland NE FL where cloudier conditions are likely. The Atlantic sea breeze will keep the beaches cooler with max temps in the upper 80s. Tonight, any lingering convection near the I-75 corridor will shift west and dissipate early this evening. Meanwhile to the north, a slow-moving frontal boundary will approach the Altamaha and stall somewhere across central GA. Moisture pooled ahead of the front and may lead to areas of low stratus and patchy fog across inland SE GA late tonight. Inland temps will be a bit warmer tonight due to the increasing moisture with lows 70s rather than the mid/upper 60s we've enjoyed the last few nights. .SHORT TERM [Tuesday Through Wednesday Night]... During this period, a mid level ridge will be over the forecast area but getting squeezed between a mid level trough moving into the southeast states, and an inverted trough/mid/upper trough moving into the south FL area. Early on Tuesday, prevailing low level flow is light southeast over northeast FL but more varied over southeast GA due to a lingering sfc trough. A weak front will start to push down toward the area Tue-Tue night but may stall near the Altamaha River Basin region due to the stronger mid level ridging in place. NAM shows it moving into our southeast GA zones Tue aftn but uncertain due to deep convective development and any outflow boundaries. The light southeast flow will allow for the east coast sea breeze to push inland during the morning and aftn while the west coast sea breeze is able to push into inland northeast FL in the aftn. While moisture starts out relatively low around 1.3-1.6 inches PWATs, they are expected to rise closer to 1.7 or 1.8 inches in the late aftn, and then increase further Tue night. Initial development of convection expected to be along the sea breezes and then increase through the peak heating of the aftn. Will generally show chance POPs roughly in the 30-50 percent range, which is near or just above the consensus. Tuesday night...anticipate the front still laying out nearly stationary across south central GA or near the Altamaha River Basin with mean low level flow generally south-southeast to southeast. Most of the scattered convection from the afternoon will be inland areas and fade slowly through the evening and overnight, and showing chance POPs for now. Wednesday...the diffuse front over southern GA will remain nearly stationary through Wed night while dissipating, and low level flow will be southeast, then transition to more east-southeast as the front weakens. Mid level ridge aloft weakens as the mid level trough over south FL works northward. Greater instability and elevated PWATs near 1.7 to 2 inches, or just above 2 inches, will lead to higher rain chances. Will have chance POPs along the coast and likely (60%+) inland areas as the focus of showers and storms propagate inland with Atlantic sea breeze during peak heating on mean steering flow from the southeast. Temps during the period look to be near normal, upper 80s to near 90 around the coast, and lower 90s inland. Lows mainly around 70/lower 70s. .LONG TERM [Thursday Through Sunday]... The diffuse front laying generally west-east across south GA is likely to become even less defined and lift northward Thu-Fri. The flow remains southeasterly through about 850 mb then becomes more southerly over the weekend as sfc ridging builds in. The moisture levels look high both in the GFS and ECMWF guidance with PWATs up to about 2 inches or so. This combination along with mid level troughing over the area and the east coast sea breeze will lead to elevated rain chances (near and above normal) with latest fcst showing around 40-60 percent. Best chances will be inland areas for most of the period. Typical summer temperatures are expected into next weekend with highs in the lower 90s inland and upper 80s to near 90 at the coast. .MARINE... A weak trough of low pressure will shift inland today before a slow moving front approaches from the northwest tonight. The front will stall to the north Tuesday and then slowly move south into the northern waters Wednesday where it will dissipate through Thursday. An increased chance of thunderstorms expected over the area waters Tuesday through Thursday along the frontal feature. High pressure will build to northeast behind the front leading to prolonged southeasterly winds through the weekend. Rip Currents: Persistent onshore swell will lead to a solid Moderate Risk at all area beaches today and again Tuesday. .FIRE WEATHER... For today, some low RH value expected northwest of a Homerville to Jesup line and isolated high dispersion possible in the same area. Otherwise, better rain chances over northeast FL today and most areas on Tuesday and rest of the week. && .PRELIMINARY POINT TEMPS/POPS... AMG 95 69 95 72 91 / 10 10 50 40 70 SSI 88 77 89 77 88 / 10 10 30 30 50 JAX 90 72 92 73 90 / 10 10 30 30 50 SGJ 87 75 90 75 90 / 30 10 30 20 40 GNV 91 72 93 73 92 / 30 10 50 30 60 OCF 91 72 93 73 93 / 30 20 50 30 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. &&