####018005832#### FXUS62 KJAX 031714 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 114 PM EDT Fri May 3 2024 ...New AVIATION... .UPDATE... Issued at 927 AM EDT Fri May 3 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 Morning fog has dissipated and the forecast is generally on track. Just minor tweaks to POPs for later today and tonight, with some showers and a few thunderstorms expected in similar areas as seen yesterday as the sea breeze penetrates inland. Activity is expected to linger over the Suwannee River Valley area and generally spread into interior GA overnight as a shortwave impulse approaches the area. Only marginal elevated instability and weak flow aloft should essentially curtail any strong or severe potential. && .NEAR TERM... Issued at 323 AM EDT Fri May 3 2024 Over the next couple of hours the main concern will be localized fog. Dense fog cannot be entirely ruled out but have left it out of the forecast at the moment with generally low confidence (< 10% chance) of visibility lowering less than 1/4 mile. Any fog that does occur should lift and disperse by 9 AM or earlier. Stagnant pattern remains in place again today, featuring a stubborn surface high and supporting ridging aloft. Overall the low level pattern will stay consistent but an upper shortwave aloft will shove ridging aloft eastward late this evening and overnight. Strong subsidence and dry air should cap much of the convective attempts along the Atlantic sea breeze this afternoon. Enhanced moisture entering from the west in combination with an Atlantic/Gulf sea breeze interaction may spark isolated to widely scattered storms well inland, near and likely west of the I-75 corridor. Instability is still on the marginal side (only progged to be around 800-1200 J/kg), thus updrafts should be fairly weak in nature and severe weather is unlikely. Tonight, the aforementioned shortwave will slowly propagate across the region resulting in increasing instability with a couple degrees of cooling aloft. This should be supportive of showers overnight mainly north of I-10 and a few elevated t-storms are also feasible through the early morning hours Saturday. Under influence of ridging aloft another seasonably warm day is on tap this afternoon with inland locations making another push toward 90F while coastal spots are cooled by the onshore flow with readings registering in the mid/upper 80s. Following the warm afternoon, temps will be mild, reading in the mid/upper 60s. 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...(Saturday through Sunday night) Showers and storms are expected this weekend as a series of short waves pass over the region with sea-breeze-driven storm developments becoming more widespread with diurnal heating. Mild easterly-southeasterly winds will persist through the period with the Atlantic afternoon sea breeze winds pushing inland. High temperatures for the weekend will reach into the mid to upper 80s with overnight low temperatures dropping down into the mid 60s over inland areas and in the upper 60s and lower 70s for areas along the coast and adjacent to the St Johns River. Patchy fog potential will exist each morning, especially in localized areas where heavy rain occurs with preceding afternoon convection. && .LONG TERM... (Monday through Thursday) Issued at 323 AM EDT Fri May 3 2024 Shortwave impulses continue to lift across the region through Monday with shower and storm developments becoming more inhibited as the week progresses due to the increased influence of upper ridging and associated subsidence extending over Florida and Georgia. Amid the stout upper ridge, winds turn offshore and enhance mixing which will boost high temperatures toward record levels as the week progresses; readings are forecast to be in the mid 90s. && .AVIATION... (18Z TAFS) Issued at 110 PM EDT Fri May 3 2024 VFR is currently prevailing at all sites. The east coast sea breeze will continue to progress inland through this evening, with a change in wind direction and speed for JAX/VQQ/GNV over the next few hours. Chances for any SHRA are very low (less than 10%) at area sites through this evening, with the best chance being at GNV. However, probability and confidence remains too low to include in the forecast. FG is expected to be limited Saturday Morning, though did include a tempo for reduced vis at VQQ. && .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 next 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. && .PRELIMINARY POINT TEMPS/POPS... AMG 67 84 65 88 / 30 70 30 60 SSI 70 81 69 82 / 10 30 20 40 JAX 66 86 67 86 / 10 30 20 50 SGJ 67 84 68 85 / 0 20 20 40 GNV 64 89 65 88 / 10 50 20 70 OCF 65 89 66 89 / 0 40 10 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ ####018004822#### FXUS62 KMFL 031715 AFDMFL Area Forecast Discussion National Weather Service Miami FL Issued by National Weather Service Austin/San Antonio TX 115 PM EDT Fri May 3 2024 ...New AVIATION... .SHORT TERM... (Today through Saturday) Issued at 246 AM EDT Fri May 3 2024 While models depict a rather complex weather pattern dominating the whole E CONUS on Friday, closer to the area a mid level ridge and sfc high pressure will remain in control of the peninsula weather during the weekend. A transient trough and associated storm systems well to the north will flatten a bit the ridge today, with pressure gradients again becoming a little tighter in the afternoon hours. Thus, expect periods of easterly winds becoming gusty, mainly over the Atlantic coast of SoFlo. Models also keep low dew points in place with the upstream air mass, which will help in keeping POPs/rain chances low. The only lifting mechanism will be again afternoon sea breezes, which will serve as focal points for limited convection to develop. But with the stronger easterly flow, it is likely that most of the shower/storm activity will be pushed towards the interior/western portions of SoFlo. The weather pattern becomes a little more favorable for afternoon showers on Saturday as an area of enhanced moisture moves into SoFlo from the Atlantic side. But model layer analyses keep most of the moisture in a shallow layer around 850-700 mb, along with highest POPs in the 25-40 percent range, favoring the Gulf coast. Any deeper convection should again follow the enhanced lifting of sea breeze boundaries, although a key difference Saturday afternoon is that overall coverage of showers seems more widespread than previous days. Despite the better chances of rain on Saturday, temperatures will remain warm on both days with afternoon highs in the mid to upper 80s for the Atlantic coast and interior areas, and around 90 for the west coast of SoFlo. && .LONG TERM... (Saturday night through Thursday) Issued at 246 AM EDT Fri May 3 2024 Long range models show mid-level ridging persisting across the region, keeping the ongoing easterly wind regime over SoFlo through much of the work week. Meanwhile, the remaining enhanced low level moisture from the weekend will gradually dry out, with mainly single digit POPs by mid week. Thus, expect better chances for a few showers and an isolated storm or two on Sunday and Monday afternoon. Again, deeper convection should follow the sea breeze boundaries as the easterly flow push them inland. Expect temperatures to remain around or slightly higher than normals. Afternoon highs will reach the upper 80s to around 90 across southwest Florida and interior areas, while remaining in the mid 80s along the east coast. Overnight lows will be in the 60s, && .AVIATION... (18Z TAFS) Issued at 107 PM EDT Fri May 3 2024 VFR flight conditions are expected to primarily prevail through the TAF operational period at the local aerodromes. Kept VCSH at KAPF as some isolated showers and/or weak convection across portions of southwest Florida. Light to moderate east to east-southeasterly flow will continue. The only exception is KAPF for a time this afternoon where the flow becomes west-southwesterly thanks to the influence of any of the sea breeze and any isolated showers/weak convection in that region. .MARINE... Issued at 246 AM EDT Fri May 3 2024 Outside of periods of gusty easterly winds, overall benign conditions should prevail across the coastal waters through the weekend. Scattered showers and a few thunderstorms are possible each day, which could bring brief periods of rough seas and gusty winds. Seas will generally remain at 2 to 4 feet in the Atlantic waters and 2 feet or less in the Gulf waters. Winds could peak in the 12-15 kts range out of the east. && .PRELIMINARY POINT TEMPS/POPS... Miami 74 84 74 84 / 20 20 10 30 West Kendall 71 85 72 86 / 20 20 10 30 Opa-Locka 73 86 73 86 / 20 20 10 30 Homestead 73 85 73 85 / 20 20 20 30 Fort Lauderdale 74 83 74 83 / 30 20 20 30 N Ft Lauderdale 74 84 74 84 / 30 30 10 30 Pembroke Pines 73 87 73 87 / 30 20 10 20 West Palm Beach 72 84 72 84 / 20 20 10 20 Boca Raton 73 84 74 85 / 40 20 10 30 Naples 71 88 71 89 / 20 40 10 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Saturday evening for FLZ168. AM...None. GM...None. && $$ SHORT TERM...AR LONG TERM....AR AVIATION...99 ####018005600#### FXUS63 KDLH 031715 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 1215 PM CDT Fri May 3 2024 .KEY MESSAGES... - Areas of Dense Fog expected early this morning around Lake Superior, including around the Twin Ports. - Widespread rain arrives this evening and will persist into Saturday. Thunderstorms are unlikely with this system. - Additional chances for rain arrive early to mid next week, with a high potential for widespread soaking rainfall. Thunderstorms will be more likely with the system next week. && .DISCUSSION... Issued at 442 AM CDT Fri May 3 2024 Areas of dense fog have developed this morning in the wake of an occluded frontal passage. This fog is a result of a combination of low to near-zero dewpoint depressions, relatively light winds, and low-level moisture lingering from rain showers last evening. Visibility of one quarter of a mile or less has been observed early this morning, mainly in areas adjacent to Lake Superior and especially around the Twin Ports. A Dense Fog Advisory has been issued until 8 AM CDT today for this dense fog. Expect fog to dissipate shortly after sunrise as diurnal heating begins and southwest winds increase from a tightening pressure gradient. Once the fog dissipates, much of today will be quiet with mostly sunny skies. Southwest winds will be breezy today due to a tightening pressure gradient between low pressure over northern Ontario and high pressure over Michigan's Lower Peninsula. A shortwave will be propagating into the upper Great Plains this evening, reaching the CWA by Saturday afternoon. Widespread showers are expected to develop late this afternoon into tonight and continue into Saturday as southwest winds advect moisture into the CWA. Dynamic forcing will be favorable within the baroclinic zone of this shortwave, with strong FGEN expected at 850mb. CAMs are in solid agreement that a southwest to northeast oriented band of rain will develop, with highest QPF amounts of 0.3-0.45" very likely (70% chance) to occur along a line from the Brainerd Lakes to the Twin Ports and north to the northern end of the Gunflint Trail. A rumble of thunder is possible from embedded thunderstorms this evening into tonight, but the potential is low (<15% chance) due to limited instability. Showers will be tapering off Saturday afternoon as the shortwave trough axis swings through the region. High pressure developing behind this shortwave will bring mostly sunny skies to the area on Sunday with comfortable high temps in the 60s. Dry conditions will linger into Monday before the next chance for rain arrives Monday night as a negatively-tilted trough enters the upper Midwest. Precip onset timing is still uncertain with this early week system, as run- to-run model variations have been trending later in recent runs of the global deterministic models. Despite timing differences, confidence is high (80% chance) that large portions of the CWA will receive a good soaking rain on Tuesday into Wednesday. Global ensemble total QPF means are around 0.5-1.5", with individual members showing the potential for locally higher rainfall amounts. Severe weather and localized flash flooding potential will need to be monitored as we get closer to early next week. At this time, it's still too uncertain for specifics on impacts and exact location. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1216 PM CDT Fri May 3 2024 VFR conditions this afternoon will diminish to MVFR conditions this evening at most sites, becoming IFR for a period overnight for at least DLH, HIB, and BRD as rain showers, low ceilings, and fog move in from the southwest. Low ceilings stick around through mid morning, with gradually clearing at all sites. INL will miss out on most of the precip/low clouds and remain VFR through the TAF period, with perhaps some MVFR ceilings early Saturday morning through late morning. At HYR rain showers arrive later with not as low ceilings expected due to drier air at low around levels, but still a period of IFR conditions Saturday morning. Strong southwest winds gusting to around 30 knots today persist through the afternoon, becoming light tonight into Saturday with west winds around 5 knots. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 1202 PM CDT Fri May 3 2024 A Marine Dense Fog Advisory has been issued this morning for all nearshore waters of western Lake Superior until 8 AM CDT. Observations show that visibility of 1 NM or less will be possible until southwest winds increase and daytime heating begins. Expect winds to turn southwesterly today and become strong up to 25 knots through the day, mainly along the North Shore and for South Shore Waters around and west of the Apostle Islands archipelago. A Small Craft Advisory has been issued today for most nearshore waters, excluding Oak Point to Saxon Harbor. Expect breezy southwest winds to ease this evening as the pressure gradient relaxes. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. MARINE...Small Craft Advisory until 10 PM CDT this evening for LSZ121- 140>147-150. && $$ DISCUSSION...Unruh AVIATION...JJM MARINE...Unruh ####018009711#### FXUS63 KLMK 031716 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 116 PM EDT Fri May 3 2024 ...Updated Aviation Discussion... .KEY MESSAGES... * Widespread showers with isolated embedded thunderstorms this morning. Scattered thunderstorms possible this afternoon. * Probability of thunder is 15-25% in the morning, increasing to 40-50% this afternoon even as rain chances decrease. * Showers and thunderstorms will be more scattered on Saturday, though forecast confidence in exact timing and coverage remains low. * Increasing potential for strong to severe thunderstorms and flooding next Tuesday through Thursday, though confidence is still low. && .UPDATE... Issued at 1014 AM EDT Fri May 3 2024 Regional radar mosaic shows the early morning widespread precip shield is shifting off to our east as expected, with some scattered showers in the wake. Precip coverage will diminish for the midday hours, with only some scattered showers expected across the area as the cold front continues to approach from the west-northwest. Around or shortly after 18z, we should begin to see additional scattered showers and storms fire up in a marginally unstable but moist environment. Soundings continue to support slow moving and unorganized convection this afternoon with skinny CAPE profiles and weak shear. However, PWATs are already 1.5" across the forecast area this morning, and those will persist for the rest of today. As a result, heavy rain and lightning will be the main threats with scattered storms this afternoon. Probability of thunder increases to 40-50% after 18z and will diminish this evening as peak heating is lost. Forecast is in great shape and no changes are planned at this time. && .SHORT TERM /THROUGH TONIGHT/... Issued at 326 AM EDT Fri May 3 2024 Warm advection/isentropic lift have spawned a band of light to moderate showers ahead of the incoming cold front. Precip shield is just starting to expand east of the I-65 corridor, but very few lightning strikes have been observed as instability is lacking thus far. Expect this band to push through most of the area by mid-morning, with a minimal break before the weak cold front comes in from the W- NW in the afternoon. Not looking for much of an opportunity to warm up, but in a muggy air mass with PWATs near 1.5 inches, sfc temps in the mid 70s are all that's needed for some marginal instability. Wind speeds are generally 25 kt or less in fairly deep SW flow, so not enough shear to support storm organization. Long story short, there's a slight (15-20%) chance for embedded thunder in the band of showers this morning, with scattered (~30% coverage) thunderstorm development possible in the afternoon. We are not expecting an all- day rain, but brief moderate rainfall is possible in any of the heavier showers or thunderstorms. Precip chances taper down this evening and overnight given the lack of heating or identifiable sources of lift. However, in the increasingly moist environment it won't take much, so will hold at least a slight chance through the night. Better chances will be east of I-65 and south of the Bluegrass Parkway into south-central Kentucky, where we could see a weak impulse lifting NE from the Deep South. Forecast confidence is high that we'll see showers at some point. At best medium confidence in thunder, as well as any specific timing. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 326 AM EDT Fri May 3 2024 Saturday and Saturday Night... Saturday's forecast continues to look tricky as far as precipitation chances are concerned, with forecast confidence in timing and coverage of showers and thunderstorms remaining low. The synoptic scale pattern for Saturday and much of the weekend will not be dissimilar to a typical mid-late summer pattern, with positive height anomalies stretching across much of the eastern one-third of the CONUS and better dynamic support from faster flow aloft remaining well to the northwest of the Ohio Valley. The front which will bring increased chances for rain later today will dissipate before clearing the region, leaving a moist unstable airmass in place for the day on Saturday. 00Z HREF mean sfc dewpoint progs are in the mid 60s Saturday afternoon, with mean PW values ranging from 1.25-1.5", with slightly lower values in southern IN. A combination of hi-res and global model sounding progs show anywhere from 1000-2000 J/kg SBCAPE, and forecast highs on Saturday are expected to exceed convective temperatures. However, as referenced above, there will be a lack of large-scale dynamic support, and convective initiation will likely be determined by the existence/location of differential heating boundaries and other gradients on the mesoscale and smaller. Due to the inherent lack of predictability of these factors, the best forecast still looks to be for a broad area of chance to likely PoPs Saturday afternoon, with lower probabilities along and north of the Ohio River, and higher probabilities south of the western KY/Bluegrass Parkways. The chance for thunderstorms will be closely tied to PoPs, as the amount of available instability will mean that any area of convection strong enough to produce rain will have a roughly equal chance to produce thunder. Severe thunderstorms are not expected on Saturday, as weak flow aloft results in only 5-15 kt of effective bulk shear (depending on model), with garden-variety thunderstorms expected. Finally, any storms which do form will be fairly slow movers, with cloud layer mean winds supporting storm motions from WSW to ENE around 15 mph. A more organized wave of showers and embedded thunderstorms is expected late Saturday night into Sunday morning as another decaying mid-level disturbance and sfc cold front falls apart in the vicinity of the Ohio Valley. Once again, weak flow aloft will curtail any severe potential, and precipitation coverage along the front will decrease as it crosses the region from west to east. Sunday and Next Week... A prolonged period of active weather looks likely over the next 5-7 days with global ensemble guidance in relatively good agreement on the large scale pattern across North America. For Sunday into Monday, the upper level trough over the north central U.S. and Canada will lift east-northeast into eastern Canada, with upper level ridging setting up across much of the eastern CONUS in its place. The trough's northeastward exit will mean that the humid and warm air mass over the central and eastern CONUS will continue with little modification, meaning that diurnally-driven showers and thunderstorms would be expected to continue. Additionally, transient mid-level perturbations within large scale SW flow are expected to swing through the Ohio Valley Sunday into Monday, bringing temporarily enhanced waves of precipitation. These showers and storms would largely be sub-severe and disorganized, as flow aloft will still be too weak to support an organized severe threat. Temperatures will remain above normal, particularly nighttime lows, which will be held higher by elevated low-level moisture content. The severe potential is expected to increase for Tuesday through the middle portion of next week, as upper troughing over the western half of the CONUS ejects into the central Plains, increasing large- scale baroclinicity and, by extension, the strength of the flow aloft across the Mississippi and Ohio Valleys. At this time, confidence in specific threats and timing is very low; however, many ensemble/machine learning/analog severe convection forecasting tools indicate elevated potential for severe weather across our region next Tuesday-Thursday. With several rounds of heavy rain/storms expected over the next week, flooding potential will also need to be monitored, especially the later we go into next week. At this time, HEFS/NAEFS guidance indicate most rivers should remain below action stage; however, these models will not resolve convectively enhanced rainfall totals well, and they still show rising levels over the next 5-8 days. && .AVIATION /18Z TAFS THROUGH 00Z SUNDAY/... Issued at 116 PM EDT Fri May 3 2024 Low confidence forecast for this TAF package, with restricted flight categories expected to continue over the next 24 hours. Terminals are mainly MVFR this afternoon, though ceilings have been around the threshold between MVFR and IFR. The cold front will be bisecting our region this afternoon and evening, which will possibly fire off a round of scattered showers and thunderstorms. We included TS mention for BWG and SDF until this evening, and that's a low enough probability to continue to handle with VCTS/CB mentions. The cold front will stall and fade out overnight, leaving a moist air mass in place that will be favorable for fog and low stratus for tomorrow morning. Included IFR mention, some in TEMPO groups, for the 08-14z time frame tomorrow. Additional VCSH is possible tomorrow too, but confidence remains low on those chances at this time. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ UPDATE...CJP SHORT TERM...RAS LONG TERM...CSG AVIATION...CJP