####018006887#### FXUS63 KJKL 041255 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 855 AM EDT Sat May 4 2024 .KEY MESSAGES... - A shower and thunderstorm potential lasts through the next 7 days. - Above normal temperatures are forecast through most of the next week. A cold front should pass late in the week and bring readings down to near or below normal. && .UPDATE... Issued at 855 AM EDT SAT MAY 4 2024 Issued an update primarily to get forecast grids in tolerance with neighboring offices. Otherwise, the current forecast for this morning looks satisfactory. UPDATE Issued at 700 AM EDT SAT MAY 4 2024 The forecast overall is looking pretty good early this morning. Isolated showers and storms area moving through portions of the area, per the current forecast, and should gradually increase in coverage through out the day, especially this afternoon during peak heating. The latest obs were used to establish new trends in the forecast grids, but as mentioned earlier, things are in pretty good shape so far. The pre-first period that was included with the 4 am forecast package will need to be removed in an hour or so, but until then, things should be good as is. && .SHORT TERM...(Today through Sunday) Issued at 449 AM EDT SAT MAY 4 2024 Isolated rain showers were ongoing at time of forecast issuance early this morning, and were beginning to slowly increase in coverage, especially north of the Mountain Parkway. This trend is expected to continue through sunrise this morning. Once the sun is up, isolated to scattered showers are expected to fire across eastern Kentucky. The primary challenge in the short term portion of the forecast will be how widespread will showers and storms become today. To answer that question, the latest model data was consulted and revealed that in spite of ample moisture and instability being in place, the lack of a clear cut triggering mechanism will limit shower and storm coverage today. With several models all supporting this scenario, the HRRR, NAMNEST, and CAMS in particular, it made sense to go with much lower precip chances for today than previously forecast. The same scenario looks reasonable for Sunday as well. The 6Z analysis showed a stationary front in place from the eastern Great Lakes into southwestern Indiana and then across Missouri where it merged with a surface low situated over southeastern Nebraska. A weak trough of low pressure was also analyzed over central Kentucky, just south of the Ohio River, but due to the weakness of this feature, it appears it will not offer enough lift to spark widespread convection today. Instead, it looks like todays showers and storms will be diurnally driven, and will peak in coverage this afternoon into early this evening, before quickly tapering off after dark, when instability will also quickly wane. Another frontal boundary extended southwestward through Kansas into far western Oklahoma and then further west out to Nevada. A well defined dry line was also in place extended southward from a surface over the Oklahoma pan handle through eastern New Mexico and across extreme western Texas. This set of boundaries and surface lows will be the focus for severe weather across the southern Plains later today. Temperatures will continue to run above normal over the weekend, with todays highs maxing out in the upper 70s, and Sundays max readings in the upper 70s and lower 80s. Tonights lows should fall to around 60, with only minimal ridge valley differences due to extensive cloud cover and little radiational cooling expected. No significant weather concerns are expected at this time, with only garden variety thunderstorms on tap today and tomorrow. Winds should be generally from the south or southwest and 5 to 10kts today and tomorrow, and light and variable tonight. .LONG TERM...(Sunday night through Friday) Issued at 449 AM EDT SAT MAY 4 2024 The long term period continues to look wet. Prevailing large scale flow aloft will be persistent from the west southwest through at least Thursday, while low level flow is out of the southwest off the gulf. This pattern of warm/moist advection will favor precip whenever there are triggers/forcing mechanisms. A wavering frontal boundary will approach from the northwest at times, but being largely parallel to the upper level flow until near the end of the period it is not likely to make a forceful passage until then. This will leave us in a modestly humid air mass with surface dew points mainly in the lower to mid 60s. The main drivers for precip will be mid/upper level waves along with diurnal heating/destabilization cycles. The mid/upper level waves with the most agreement in the models are ones that would affect us on Monday, and also Wednesday night into Thursday, and these time frames contain the highest POP area wide at mainly 70%+. There are some model discrepancies in the Thursday-Friday time frame concerning timing of an eventual cold frontal passage. In the 00Z deterministic/operational runs, the GFS is faster than the ECMWF with the passage of the primary cold front, and this results in lower forecast confidence. The current forecast is a model blend, but temperatures are likely to end up being either warmer or colder, depending on timing of cold fropa. Also, a faster fropa would result in the POP dropping off faster, and a slower passage would allow precip to linger longer. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) ISSUED AT 700 AM EDT SAT MAY 4 2024 MVFR CIGs at SME and SYM to begin the 12Z forecast period, with JKL, LOZ, and SJS holding at VFR. Isolated showers and storms were moving through the area at TAF issuance. These will continue to gradually increase in coverage through out the day, especially this afternoon and early this evening during peak heating and instability. The rain is not expected to be widespread, but enough showers and storms will be around to warrant VCTS mention at each TAF airport later today into early this evening. Winds will be generally from the south or southwest at 5 to 10 kts today and light and variable overnight. MVFR fog could affect that TAF sites toward the end of the TAF period due to any rainfall that is received at those locations, but confidence is not high at this time. Brief periods of IFR could also occur at any TAF site during a thunderstorm, but outside of that, MVFR or VFR will be most common. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CMC SHORT TERM...AR LONG TERM...HAL AVIATION...AR ####018006901#### FXUS63 KJKL 041256 CCA AFDJKL AREA FORECAST DISCUSSION...CORRECTED National Weather Service Jackson KY 856 AM EDT Sat May 4 2024 .KEY MESSAGES... - Shower and thunderstorm potential lasts through the next 7 days. - Above normal temperatures are forecast through most of the next week. A cold front should pass late in the week and bring readings down to near or below normal. && .UPDATE... Issued at 855 AM EDT SAT MAY 4 2024 Issued an update primarily to get forecast grids in tolerance with neighboring offices. Otherwise, the current forecast for this morning looks satisfactory. UPDATE Issued at 700 AM EDT SAT MAY 4 2024 The forecast overall is looking pretty good early this morning. Isolated showers and storms area moving through portions of the area, per the current forecast, and should gradually increase in coverage through out the day, especially this afternoon during peak heating. The latest obs were used to establish new trends in the forecast grids, but as mentioned earlier, things are in pretty good shape so far. The pre-first period that was included with the 4 am forecast package will need to be removed in an hour or so, but until then, things should be good as is. && .SHORT TERM...(Today through Sunday) Issued at 449 AM EDT SAT MAY 4 2024 Isolated rain showers were ongoing at time of forecast issuance early this morning, and were beginning to slowly increase in coverage, especially north of the Mountain Parkway. This trend is expected to continue through sunrise this morning. Once the sun is up, isolated to scattered showers are expected to fire across eastern Kentucky. The primary challenge in the short term portion of the forecast will be how widespread will showers and storms become today. To answer that question, the latest model data was consulted and revealed that in spite of ample moisture and instability being in place, the lack of a clear cut triggering mechanism will limit shower and storm coverage today. With several models all supporting this scenario, the HRRR, NAMNEST, and CAMS in particular, it made sense to go with much lower precip chances for today than previously forecast. The same scenario looks reasonable for Sunday as well. The 6Z analysis showed a stationary front in place from the eastern Great Lakes into southwestern Indiana and then across Missouri where it merged with a surface low situated over southeastern Nebraska. A weak trough of low pressure was also analyzed over central Kentucky, just south of the Ohio River, but due to the weakness of this feature, it appears it will not offer enough lift to spark widespread convection today. Instead, it looks like todays showers and storms will be diurnally driven, and will peak in coverage this afternoon into early this evening, before quickly tapering off after dark, when instability will also quickly wane. Another frontal boundary extended southwestward through Kansas into far western Oklahoma and then further west out to Nevada. A well defined dry line was also in place extended southward from a surface over the Oklahoma pan handle through eastern New Mexico and across extreme western Texas. This set of boundaries and surface lows will be the focus for severe weather across the southern Plains later today. Temperatures will continue to run above normal over the weekend, with todays highs maxing out in the upper 70s, and Sundays max readings in the upper 70s and lower 80s. Tonights lows should fall to around 60, with only minimal ridge valley differences due to extensive cloud cover and little radiational cooling expected. No significant weather concerns are expected at this time, with only garden variety thunderstorms on tap today and tomorrow. Winds should be generally from the south or southwest and 5 to 10kts today and tomorrow, and light and variable tonight. .LONG TERM...(Sunday night through Friday) Issued at 449 AM EDT SAT MAY 4 2024 The long term period continues to look wet. Prevailing large scale flow aloft will be persistent from the west southwest through at least Thursday, while low level flow is out of the southwest off the gulf. This pattern of warm/moist advection will favor precip whenever there are triggers/forcing mechanisms. A wavering frontal boundary will approach from the northwest at times, but being largely parallel to the upper level flow until near the end of the period it is not likely to make a forceful passage until then. This will leave us in a modestly humid air mass with surface dew points mainly in the lower to mid 60s. The main drivers for precip will be mid/upper level waves along with diurnal heating/destabilization cycles. The mid/upper level waves with the most agreement in the models are ones that would affect us on Monday, and also Wednesday night into Thursday, and these time frames contain the highest POP area wide at mainly 70%+. There are some model discrepancies in the Thursday-Friday time frame concerning timing of an eventual cold frontal passage. In the 00Z deterministic/operational runs, the GFS is faster than the ECMWF with the passage of the primary cold front, and this results in lower forecast confidence. The current forecast is a model blend, but temperatures are likely to end up being either warmer or colder, depending on timing of cold fropa. Also, a faster fropa would result in the POP dropping off faster, and a slower passage would allow precip to linger longer. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) ISSUED AT 700 AM EDT SAT MAY 4 2024 MVFR CIGs at SME and SYM to begin the 12Z forecast period, with JKL, LOZ, and SJS holding at VFR. Isolated showers and storms were moving through the area at TAF issuance. These will continue to gradually increase in coverage through out the day, especially this afternoon and early this evening during peak heating and instability. The rain is not expected to be widespread, but enough showers and storms will be around to warrant VCTS mention at each TAF airport later today into early this evening. Winds will be generally from the south or southwest at 5 to 10 kts today and light and variable overnight. MVFR fog could affect that TAF sites toward the end of the TAF period due to any rainfall that is received at those locations, but confidence is not high at this time. Brief periods of IFR could also occur at any TAF site during a thunderstorm, but outside of that, MVFR or VFR will be most common. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CMC SHORT TERM...AR LONG TERM...HAL AVIATION...AR ####018006725#### FXUS62 KJAX 041256 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 856 AM EDT Sat May 4 2024 ...New UPDATE... .UPDATE... Issued at 847 AM EDT Sat May 4 2024 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf Forecast remains on track as mid level trough pushing through the SE US is enhancing ongoing convection across inland SE GA with pockets of heavy rainfall just to the west of Waycross with isolated totals of 2-3 inches. The moisture associated with this trough will spread to the SE and interact with local sea breeze circulations across coastal SE GA and NE FL where scattered afternoon showers and storms are expected, where more heating well into the 80s will provide enough instability for a few strong storms with gusty winds to 40-50 mph and locally heavy rainfall. Convection should fade after sunset this evening and shift into the Atlantic Coastal Waters with partial clearing during the overnight hours and patchy/areas of fog can be expected over inland areas, especially where rainfall occurs today. && .NEAR TERM...Today and Tonight... Fog development this morning will be fairly sparse and generally shallow, as elevated southerly flow maintains a somewhat mixed boundary layer. Otherwise, a few showers continue to stream across inland southeast GA early this AM as upper level diffluence enhances downstream from an approaching shortwave just to the west. As that shortwave makes its way slowly eastward, the associated cooling aloft and moistening mid levels will offer a sufficient amount of diurnal instability this afternoon. With those ingredients in play along with the sea breezes, scattered to numerous showers are expected to develop during the mid and late afternoon hours, mainly across interior SE GA and inland NE FL west of Highway 301. Steep low level lapse rates will allow potentially strong outflow winds in the vicinity of pulsing storms. Outflow and sea breeze interaction may lead to a few strong storms this afternoon and evening. Given a fairly weak westerly steering flow, motion of storms today will be outflow driven with a tendency to slowly drift back toward the east coast as they weaken. In addition to a few strong gusts with the more robust convection, PWATs pushing toward the 90th percentile according to sounding climo will allow for localized heavy rain (which will be beneficial given the ongoing dry spell). Convective debris clouds will drift eastward tonight as convection wanes with mostly quiet conditions through the overnight hours. There will be another chance for at least patchy inland fog, particularly in locations that receive a decent amount of rain. Temps today will be modulated by cloud cover and the onshore flow which should keep most of SE GA and coastal NE FL high temp readings in the low/mid 80s while the rest of NE FL warms into the upper 80s to near 90 this afternoon. Another mild night will follow the warm afternoon with lows in the mid/upper 60s except at the coast where onshore flow will keep lows from falling below 70F. For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf && .SHORT TERM...(Sunday through Monday night) Pattern of diurnal convection will continue through Sunday and Monday as a series of mid level short waves pass over the region. Shower and storm developments are expected to be largely scattered with developments becoming more numerous along the diurnal sea breeze boundaries and areas of convergence. High temperatures for this period will be in the upper 80s and lower 90s for inland areas and in the lower to mid 80s along the coastline. && .LONG TERM...(Tuesday through Friday) Predominantly dry weather through the rest of the week as high pressure ridging dominates the weather pattern. Sea breeze winds will be largely pinned to the coast by midweek as prevailing flow shifts to become more out of the southwest due to the positioning of the high pressure axis. Temperatures will rise into the mid 90s as the week progresses with temps potentially reaching record seasonal levels by the end of the period. && .AVIATION... (12Z TAFS) Issued at 717 AM EDT Sat May 4 2024 Amid a more unstable airmass, sea breeze interaction and a passing disturbance will lead to scattered thunderstorms mainly along and east of Highway 301 during the late afternoon (after 20z). Convective impacts are most likely at KGNV; however, outflow may impact terminals with vicinity showers/storms. As storms weaken this evening, the remnant showers will drift eastward and possibly pass across coastal terminals in NE FL. Outside of outflow influence, predominant winds will be east to east-southeasterly around 7-12 knots then trending lighter after 00z. Late in the TAF period expecting better chances for at least MVFR fog/stratus development in the moist airmass at VQQ/GNV after 07Z. && .MARINE... High pressure will remain anchored northeast of the local waters through the weekend. Afternoon sea breeze development will continue each afternoon for the next several days as high pressure repositions further south, shifting winds toward a southeasterly direction early this week. Winds should trend offshore toward the end of next week as a cold front approaches from the northwest. Rip Currents: Risk will only increase to a low-end moderate level as the Atlantic sea breeze develops during the afternoon hours. Otherwise, low surf and light wind will keep risk low. && .CLIMATE... Issued at 219 PM EDT Fri May 3 2024 Daily record Maximum Temperatures at the local climate sites for... Tuesday May 7th...JAX 94/1977...CRG 94/1977...GNV 96/1955...AMG 93/1962 Wednesday May 8th...JAX 96/1959...CRG 93/1977...GNV 97/1955...AMG 95/1962 Thursday May 9th...JAX 96/1962...CRG 93/2008...GNV 95/2011...AMG 95/1962 Friday May 10th...JAX 94/2017...CRG 95/2003...GNV 95/2011...AMG 95/2011 && .PRELIMINARY POINT TEMPS/POPS... AMG 84 64 88 66 / 60 40 50 20 SSI 79 70 82 69 / 20 20 40 20 JAX 85 67 87 66 / 30 20 40 10 SGJ 83 68 85 68 / 20 20 40 10 GNV 88 66 88 65 / 40 40 60 10 OCF 90 66 89 66 / 40 40 60 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$