Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/13/21

Area Forecast Discussion
National Weather Service Jacksonville FL
856 PM EDT Wed May 12 2021 .UPDATE... Low level clouds are building in following the storm passage with winds building in from out of the north overnight. Scattered showers and drizzle can be expected to move through the forecast area overnight with overnight low temperatures dropping down into the mid to lower 50s in southeast Georgia and ranging between the upper 50s and mid to upper 60s through northeast Florida. && .PREV DISCUSSION [758 PM EDT]... .NEAR TERM [Through Tonight]... A slow moving cold front stretches across Srn SC and central GA this afternoon, a little south of an arc from near Charleston, SC to near Warner Robins. South of this front, our area remains in a warm, humid, moderately unstable airmass. RAP analysis data shows ML CAPE values in NE FL and coastal SE GA to be around 1000-1500 J/kg with effective bulk shear around 35-40 knots. There`s a Marginal Risk of severe storms, with the main hazards being gusty winds and small hail. The greater risk area for more intense storms is still along the I-95 corridor of NE FL where sea breeze is pinned close to the coastline and easterly low level flow is in place beneath westerly mid-level flow, leading to directional vertical shear as well as slightly stronger speed shear (45 kts). The cold front boundary will sink steadily south through our area overnight tonight, but thick low level clouds and lingering rain showers behind the front could last into Thursday morning, resulting in moderated low temperatures tonight. Lows will be in the low-mid 50s in SE GA, and in the 60s in NE FL. .SHORT TERM [Thursday Through Friday Night]... A bit of a tricky forecast for Thursday. The cold front is poised to push just south of our forecast area by Thursday morning, but with strong northeasterly onshore flow behind the front, we may be stuck under a thick deck of low level clouds with light rain showers or drizzle hanging in through much of the day. How long we`re stuck in those breezy, cloudy, drizzly conditions will determine how much we will actually warm up on Thursday. Model guidance has been pretty consistent with highs in the low-mid 60s in SE GA over the last several runs, but how far south those temps in the 60s will dig has been more up in the air. Current forecast roughly keeps those 60s along and north of I-10, with temperatures warming into the 70s south of I-10. Showers should exit offshore Thursday night, with drier conditions anticipated for Friday. As a ridge of low level high pressure moves eastward, a cooler, drier air mass will push in. Friday should be nice day with clearing skies and highs in the mid-upper 70s over most of the area, around 80 near Ocala and Gainesville. Lows will be mostly in the 50s both nights, with low 60s near the beaches. .LONG TERM [Saturday Through Wednesday]... Deep layer ridging forecast over the area for this weekend, with the low level ridge centered over the TN Valley Saturday and the upper level ridge axis over the north-central Gulf coast Saturday, with both sliding eastward through the weekend. Under mostly sunny skies, temperatures will gradually warm, with highs forecast to return to the 80s across the area on Sunday afternoon and upper 80s to low 90s forecast Tuesday and Wednesday. Winds will become more easterly next week as the ridge continues to roll eastward and when combined with the increasing temperatures will likely lead to the return of scattered seabreeze showers and thunderstorms around mid-week. .AVIATION... [Through 00Z Friday] Showers and thunderstorms have moved offshore for most of the region, with lingering developments near SSI and south of SGJ. Ceilings are expected to drop to IFR levels overnight with gusty winds building from out of the north to about 10-15 knots with gusts of 20 knots. Ceilings should lift to be above 1000 feet by Thursday afternoon. .MARINE... A cold front lies just north of our coastal waters this afternoon and will continue to nudge south into Georgia waters this evening and the northeast Florida waters overnight. Ahead of the front, showers and thunderstorms will increase over the waters and will continue to move south through tonight. Behind the front, shower activity may continue to linger through Thursday afternoon. Winds will shift to the northeast and increase in speed behind the front, allowing seas to build as well. Small Craft Advisory conditions will develop tonight and last into Friday night. Rip Currents: Moderate risk of rip currents this afternoon, high risk of rip currents tomorrow at all area beaches. .FIRE WEATHER... Rounds of showers and thunderstorms will continue through tonight ahead of an approaching cold front, with lingering showers possible behind the front tomorrow. Strong northeast winds are forecast along the coastline from Thursday through much of the weekend, but further inland winds will be lower, and when combined with low mixing heights, will lead to low-end daytime dispersions (around 20-30) across inland portions of the area Thursday. && .PRELIMINARY POINT TEMPS/POPS... AMG 52 64 51 75 50 / 50 40 10 0 0 SSI 57 66 59 73 61 / 60 60 10 0 0 JAX 60 67 57 75 58 / 40 50 10 10 0 SGJ 66 71 62 74 63 / 50 50 20 10 0 GNV 63 74 56 79 55 / 30 40 10 0 0 OCF 67 79 60 81 57 / 30 40 10 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...Small Craft Advisory until 8 AM EDT Saturday for Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM-Coastal waters from St. Augustine to Flagler Beach FL out 20 NM- Waters from Fernandina Beach to St. Augustine FL from 20 to 60 NM-Waters from St. Augustine to Flagler Beach FL from 20 to 60 NM. Small Craft Advisory until 8 AM EDT Saturday for Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM-Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM. &&