Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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041 FXUS62 KJAX 161822 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 222 PM EDT Sun Jun 16 2024 ...SCATTERED TO NUMEROUS THUNDERSTORMS THROUGH EARLY THIS EVENING ALONG THE I-75 CORRIDOR... ...HIGH RIP CURRENT RISK THIS WEEK AT AREA BEACHES... ...MONITORING POTENTIAL LOW PRESSURE DEVELOPMENT NEAR THE BAHAMAS TOWARDS MIDWEEK... 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 222 PM EDT Sun Jun 16 2024 Afternoon surface analysis depicts strengthening high pressure (1027 millibars) centered over New England, with a decaying frontal boundary wedging southward through the Carolinas and the southern Appalachians. Aloft...stout ridging prevails over the southeastern states, with the feature steering shortwave energy around its western periphery from the southern Plains states northeastward to the Great Lakes region. Latest GOES-East derived Total Precipitable Water imagery indicates that a drier than average air mass remains over most of our region, except for locations near the Suwannee River, where values were in the 1.6 - 1.8 inch range, which is closer to climatology. PWAT values elsewhere were generally in the 1.3- 1.5 inch range, with higher PWATS just north of our region near the decaying frontal boundary. Our local pressure gradient is tightening as high pressure wedges down the southeastern seaboard, with breezy easterly winds now in place for locations along and east of the St. Johns River, where the Atlantic sea breeze was progressing fairly quickly westward. Widely scattered convection was developing along both the inland moving Gulf and Atlantic sea breeze boundaries, generally for locations south of the I-10 corridor. Temperatures ranged from the upper 80s to lower 90s at most locations, with dewpoints falling through the 60s for locations west of the U.S. Highway 301 corridor, with 70s for locations behind the inland moving Atlantic sea breeze boundary. && .NEAR TERM... (through Tonight) Issued at 222 PM EDT Sun Jun 16 2024 Breezy easterly winds will overspread inland locations as the afternoon progresses, with onshore winds increasing to the 15-20 mph range with occasional gusts up to 30 mph by late this afternoon and early this evening along the Atlantic coast. The strengthening surface ridge along the New England coast will generally advect a dry and subsident air mass onshore, with the Atlantic sea breeze progressing well inland towards the I-75 corridor by the late afternoon hours. This boundary will encounter higher PWAT values located along and west of the Suwannee River, as it encounters a pinned Gulf Coast sea breeze. with scattered to numerous showers and thunderstorms expected to erupt by late afternoon for locations along and west of I-75 in the Suwannee Valley and north central FL. Showers and thunderstorms developing along the I-75 corridor during the mid to late afternoon hours will progress westward across the Suwannee and Alapaha Rivers by sunset. Breezy and convergent low level easterly flow may begin to advect isolated showers developing over the Atlantic waters onshore along the northeast FL coastal counties towards sunrise on Monday. The onshore breeze will be slow to weaken along the coast overnight, keeping lows in the upper 70s to around 80 for locations east of I-95, while lows elsewhere fall to the low and mid 70s. && .SHORT TERM... (Monday through Tuesday night) Issued at 222 PM EDT Sun Jun 16 2024 A persistent weather pattern is expected for this period as high pressure centered south and east of New England will continue to extend a ridge southwestward across the area. This will also continue a brisk onshore flow featuring easterly winds in the 10-20mph range with gusts around 25-35mph, and an elevated risk of rip currents at area beaches. Guidance is also in pretty good agreement that stacked high pressure to our northeast will advect some drier than normal air into the region aloft, and therefore reduce chances for any significant convection. The highest rain chances will likely be closer to the coast during this time frame with some showers and possibly an isolated thunderstorm streaming onshore. The secondary area where there may be some convective coverage would be near or west of I-75 each day as the onshore flow meets the pinned Gulf Coast seabreeze. Expecting mainly mid to upper 80s for highs during this period, with some low 90s likely for the western "half" of the CWA, dropping into the low to mid 70s and upper 70s near the coast each night. && .LONG TERM... (Wednesday through next Sunday) Issued at 222 PM EDT Sun Jun 16 2024 Wednesday/Thursday: Eyes for the this period will be primarily focused on a tropical wave east of the Bahamas on Wednesday, and the potential for further tropical organization/development as it moves west-northwestward towards our area through Thursday. It is still too far out to determine if the system will organize into a tropical cyclone, or pass near the area as a tropical wave/trough. In addition to strength and organization of the disturbance, guidance is also shaky with regards to the track, which has varied from moving towards as far north as the GA/SC border to as far south as south of Cape Canaveral, pending the strength and position of the strong steering ridge impacting the area this week. Main points to drive home as of now will be: 1. this area should pass close enough to increase rain chances area wide, including some localized heavy rain and flooding potential 2. gusty onshore conditions are likely to continue through at least the end of the week, with hazardous beach conditions also likely to persist. Friday through Sunday: Aforementioned high pressure will start to drift further south into the western Atlantic into next weekend, with ridging overhead weakening a bit in the wake of the departing disturbance. This should shift our flow more towards the southeast for the weekend and return a more normal sea breeze convection type of regime. Temperatures: Tending near to slightly below average for the start of the long term period with more unsettled weather, returning closer to normal or even slightly above normal for next weekend. && .AVIATION... (18Z TAFS) Issued at 143 PM EDT Sun Jun 16 2024 Showers and thunderstorms currently developing along the inland moving Atlantic and Gulf coast sea breezes will converge upon the Interstate 75 corridor during the mid to late afternoon hours. Vicinity showers and thunderstorms are expected during the next few hours at VQQ, with higher chances for impacts at GNV after 20Z. We kept a TEMPO group for MVFR conditions and briefly gusty winds in the 20Z-00Z window at GNV. MVFR visibilities are expected to develop at VQQ overnight, with periods of IFR visibilities possible during the predawn hours. Periods of MVFR ceilings will be possible from the predawn through late morning hours on Monday at the SSI and SGJ coastal terminals, as showers developing over the adjacent near shore waters potentially move onshore towards sunrise. These MVFR ceilings may then periodically impact the Duval County terminals after 13Z. Confidence remains too low to indicate anything other than scattered ceilings at the regional terminals during the predawn and morning hours on Tuesday. Gusty east-northeasterly surface winds that will be sustained around 15 knots this afternoon, except around 10 knots at VQQ and GNV, will persist in the 10-15 knot range overnight through the early morning hours at the coastal terminals, while speeds inland fall to around 5 knots or less after 04Z. Gusty easterly surface winds will then redevelop before 15Z Monday. && .MARINE... Issued at 222 PM EDT Sun Jun 16 2024 High pressure centered over New England will strengthen as it moves slowly offshore this evening. This feature will result in strengthening easterly winds late this afternoon and evening throughout our local waters, with winds and seas continuing to gradually increase early this week. Small Craft will need to Exercise Caution if venturing into our local waters on Monday and Monday night, as easterly winds strengthen to 15-20 knots and seas build to 3-5 feet on Monday and 4-6 feet by Monday evening. Small Craft Advisory conditions are expected to begin offshore on Tuesday and near shore by Tuesday night, as onshore winds strengthen to around 20 knots and seas build to 5-7 feet. A low pressure center is expected to develop over the southwestern Atlantic Ocean early this week, with this feature gradually organizing around midweek as it moves westward across the Bahamas, with a low risk for tropical development as this system approaches our local waters on Thursday and Thursday night. Coverage of showers and thunderstorms will gradually increase across our local waters towards midweek, with widespread activity likely by late week. Seas will continue to build, with near shore seas climbing to the 8-11 foot range by Thursday, while seas offshore build to 9-13 feet. Rip Currents: Strengthening easterly winds will result in building and increasingly rough surf, especially during the outgoing tide late this afternoon and early this evening. A High Risk of rip currents is expected by late afternoon at the northeast FL beaches, with a high end moderate risk for the southeast GA beaches, where wave heights should remain around 2 feet or less today. A high risk of rip currents is expected for the upcoming work week at all area beaches due to gradually strengthening onshore winds and building seas. && .FIRE WEATHER... Issued at 1119 AM EDT Sun Jun 16 2024 Easterly surface and transport winds will become breezy this afternoon, creating good to marginally high daytime dispersion values for locations along and north of the Interstate 10 corridor. Generally fair dispersion values are expected for north central FL this afternoon. A dry air mass will prevail for inland locations across southeast GA and also for northern portions of the Suwannee Valley today and again on Monday, where afternoon humidity values will fall to the 30-35 percent. Breezy easterly transport winds will prevail area-wide on Monday and Tuesday, with windy surface conditions expected along the I-95 corridor during the afternoon and early evening hours. Good to high daytime dispersion values are forecast throughout our region for the early to middle portions of this week. && .PRELIMINARY POINT TEMPS/POPS... AMG 72 92 71 91 / 0 10 10 20 SSI 80 87 80 85 / 10 30 20 40 JAX 74 90 73 88 / 10 20 20 50 SGJ 79 87 80 88 / 10 30 20 60 GNV 73 92 72 90 / 10 10 10 50 OCF 73 92 73 92 / 20 10 0 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through late Wednesday night for FLZ124- 125-133-138. GA...None. AM...None. && $$