####018003314#### FXUS62 KMFL 161602 AFDMFL Area Forecast Discussion National Weather Service Miami FL 1202 PM EDT Fri May 16 2025 ...New SHORT TERM, AVIATION, MARINE... .SHORT TERM... (Rest of today through Saturday) Issued at 1201 PM EDT Fri May 16 2025 It may be the start of the climatological wet season in South FL, but it's not going to look that way heading into this weekend. Upper level ridging and surface high pressure will dominate resulting in warm and dry conditions persisting. Temperatures will be several degrees above normal with highs ranging from the upper 80s near the coasts to middle 90s over interior SW FL. Dewpoints in the upper 60s to lower 70s will result in max heat indices in the mid to upper 90s across the east coast metro, and around 100 over the interior. Little relief is expected overnight with lows ranging from the upper 60s over the interior, to middle 70s closer to the coasts. && .LONG TERM... (Saturday night through Thursday) Issued at 248 AM EDT Fri May 16 2025 Surface high and ridging will persist over the Florida peninsula through the extended period. As a result, dry conditions and a warming trend will continue through the weekend and early next week. High temperatures will climb to the mid-upper 90s across southwest Florida, where heat indices could reach 103-105 degrees each afternoon. Meanwhile, overnight lows will drop to the upper 60s. Along coastal areas, seabreezes will help temper conditions during the daytime, keeping highs in the upper 80s and lower 90s. Overnight lows will remain balmy in the mid- upper 70s. Chances for rain could return near the end of the long term period. Model guidance shows a surface low developing over the midwest and dragging a surface front as it progresses eastward. If this solution pans out, the front could move across the Florida peninsula late next week, bringing isolated to scattered showers and a few thunderstorms to South Florida. Confidence regarding this outcome remains low at this time given uncertainty in timing with this system. && .AVIATION... (18Z TAFS) Issued at 1201 PM EDT Fri May 16 2025 VFR through the 18Z TAF period. Light SE winds 5-10 kts this afternoon with a westerly gulf breeze at APF. Light and variable winds late tonight and overnight. && .MARINE... Issued at 1201 PM EDT Fri May 16 2025 Benign marine conditions persist through the upcoming weekend, with light winds and seas 2 ft or less. && .PRELIMINARY POINT TEMPS/POPS... Miami 76 90 76 89 / 0 10 0 0 West Kendall 73 92 73 92 / 0 10 0 0 Opa-Locka 75 92 76 92 / 0 10 0 0 Homestead 76 90 76 89 / 0 10 0 0 Fort Lauderdale 75 89 76 88 / 0 10 0 0 N Ft Lauderdale 75 90 75 89 / 0 10 0 0 Pembroke Pines 77 94 77 94 / 0 10 0 0 West Palm Beach 74 92 74 91 / 0 10 0 10 Boca Raton 74 92 74 91 / 0 10 0 0 Naples 74 89 74 90 / 0 0 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && $$ SHORT TERM...CMF LONG TERM....ATV AVIATION...CMF ####018010382#### FXUS61 KRNK 161610 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 1210 PM EDT Fri May 16 2025 .SYNOPSIS... A warm front enters the Ohio Valley today bringing storms to this region, which will start to move into our area this afternoon into tonight. A cold front tracks across Saturday. High pressure builds in behind the front for Sunday into early next week. && .NEAR TERM /THROUGH TONIGHT/... As of 1145 AM EDT Friday... Key Messages: 1) Severe Thunderstorm Watch #261 in effect until 6PM for parts of NW NC, western VA west of the ROA Valley, and southern WV generally south of I-64.. 2) Strong to severe storms associated with a MCS forecast to cross the mountains this afternoon. 3) More storms expected tonight as another MCS moves in from KY. Severe winds/hail possible. Based on latest radar trends and SPC analysis...An arcing band of thunderstorms, Mesoscale Convective System (MCS) has developed into eastern KY. Despite shading from cloud cover east of the system, moderate insolation is underway. Coupled with steep mid- level lapse rates, as sampled in regional 12Z soundings, the plume of large buoyancy over the TN Valley will extend northeastward towards the southern Appalachians. Fast, nearly unidirectional westerly deep-layer shear should favor at least a few supercells ahead of the MCS moving east. A mix of large hail, which could be significant, along with damaging winds seems likely. A severe thunderstorm watch has been issued to account for current radar trends which suggest MCS will follow axis of developing CAPE downstream into our western CWA. Watch may need to be extended farther downstream into the piedmont (along VA/NC border) pending evolution of CAPE profiles east of the mountains...daytime heating leading to increasing instability there. Unlike yesterday where capping inversion held for the most part, this same inversion (still evident in the morning RNK sounding) should be penetrable today given the lift from the cold pool associated with the advancing MCS. Plan to send up another balloon from RNK. Special release is scheduled for 18Z. Current MCS is expected to exit the CWA this evening, leaving lull or break between yet another MCS that is expected to develop farther upstream across MO and western KY, moving east again, and crossing the southern Appalachians during the overnight. Models have trouble capturing the timing and intensity of these systems so stay tuned for future updates as these mesoscale features evolve. Highs today will be in the 80s east of the Blue Ridge and in the mid 70s to around 80 west. Lows Friday night remain elevated due to showers/higher RH, with lower to mid 60s Piedmont/foothills to upper 50s mountains. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... As of 140 AM EDT Friday... Key Points: 1. Above normal temperatures through the period. 2. Primarily morning showers on Saturday. 3. Gusty Saturday afternoon. 4. Dry Sunday. 5. Showers return to western sections late Monday afternoon and evening. A look at the 15 May 00Z NCEP Ensemble Mean 500mb Geopotential Heights shows an upper low within a trough axis over the Ontario/Quebec border by Saturday evening with the trough axis extending south into the mid-Atlantic region. Additionally, a broad upper ridge is over central CONUS, and a trough is deepening along the west coast. On Sunday, the trough over the northeast US shifts east, becoming centered over Maine by Sunday evening. The central CONUS ridge shifts east into the Mississippi River Valley, and the west coast trough deepens to a closed low centered over ID/NV/UT. On Monday into Monday night, little change is expected to the synoptic pattern from Sunday, other than a minor shift east of each feature. At the surface, an occluded surface low pressure system will be across central Quebec by Saturday evening. Its association triple point will be closer to New England, with its cold front trailing south to the Delmarva Peninsula and over eastern parts of NC. High pressure will be over central CONUS, and low pressure will be over UT. By Sunday evening, low pressure and the surface cold front will be farther to our east, with high pressure centered over the Lower Ohio Valley. Low pressure will deepen over the Rockies. By Monday evening, high pressure will be centered over our area, while low pressure moves into the Central Plains states. Monday evening, the ridge axis shifts east, beginning to open the door for moisture return. A look at the 15 May 12Z NAEFS Ensemble Situational Awareness data shows 850mb temperatures on Saturday will range from +12C to +16C, nw-se, across the region. The high end of the range will touch the 90 to 97.5 percentile of the 30-year CFSR climatology. Values cool slightly for Sunday, with a range of +12C to +15C oriented n-s. Little change in values is expected for Monday. The above weather patterns offer the following forecast. With the passage of a cold front early on Saturday, showers will be confined to primarily the mountains during the morning hours. Winds will increase from the west behind the front, helping to squelch development east of the crest of the Blue Ridge during the afternoon hours. Wind gusts could be as high as 35 to 40 mph across the higher peaks and ridges during the afternoon hours. Gusts of 20 to 30 mph will be more common across the Piedmont and mountain valley regions. Heading through Sunday into Monday, as high pressure builds into the region, look for temperatures above normal for this time of year. While Sunday is expected to be dry, by late Monday and into Monday night, some showers may be able to work their way into western parts of the region as a southerly moisture fetch returns to the area. Confidence in the above weather scenario is high. && .LONG TERM /TUESDAY THROUGH THURSDAY/... As of 150 AM EDT Friday... Key Points: 1. Near normal temperatures Tuesday and Wednesday, but cooler for Thursday. 2. Daily chances of convective showers/storms, especially on Wednesday.\ A look at the 15 May 00Z NCEP Ensemble Mean 500mb Geopotential Heights shows an upper ridge shifting east and becoming situated over our region. To its west, a upper trough is expected to be over central CONUS. On Wednesday, the center of the ridge shift to our east, and the trough axis shifts into the the Lower Ohio Valley. By Thursday, the trough continues its progress eastward, becoming centered over OH/KY/TN by Thursday evening. At the surface, a ridge of high pressure will be east of our region on Tuesday evening. Low pressure will be over the mid-Mississippi River Valley. By Wednesday evening, the ridge will continue to shift east, and low pressure will be centered over the Lower Ohio Valley. By Thursday evening, low pressure will be centered over the mid- Atlantic region. A look at the 15 May 12Z NAEFS Ensemble Situational Awareness data shows 850mb temperatures on Tuesday within a range of +11C to +15C, ne-sw across the region. For Wednesday, values cool slightly to within the +10C to +13C range, n-s. For Thursday, values drop considerably, reaching a range of +7C to +9C, nw-se, across the region. Values across the far southwest portion of the forecast area touch the 2.5 to 10 percentile of the 30-year CFSR climatology. The above weather patterns offer the following forecast. Precipitation chances will progressively increase through the period with the approach and then arrival of an area of low pressure and its associated warm/cold front. Timing of specific rounds of precipitation will be tricky, as the activity will be convective rather than an expansive stratiform in coverage. Temperatures will decrease heading into Thursday behind the system's cold front, but the track of the parent upper low may still bring showers to the region on Thursday, dependent on its track. Confidence in the above weather scenario is on the low side of moderate. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... As of 650 AM EDT Friday... Look for fog to clear out soon, with mainly VFR through the period. A few showers/possible storms may occur this morning along/west of a HSP-BCB-MKJ line. More showers/storms this afternoon but scattered nature. Amendments may be needed. Expect a better chance of showers/storsm into this evening and possibly overnight with a more organized cluster of showers/storms moving in. At the moment will have VCSH/VCTS mainly in the west tonight with possible MVFR. EXTENDED AVIATION OUTLOOK... Activity continues into early Saturday, but should see drying out heading into Saturday afternoon. So expect some periods of sub- VFR during this time. Expect clearing for Saturday night and Sunday. High pressure ridging into the Mid- Atlantic Sunday and into early next week, keeping the weather quiet with likely VFR conditions for all terminals. Unsettled weather returns Tuesday into Wednesday. && .EQUIPMENT... As of 320 AM EDT Friday... The National Weather Service Weather Forecast Office in Blacksburg, VA is continuing to conduct a required, scheduled update to their Advanced Weather Interactive Processing System (AWIPS) that began Tuesday, May 13, 2025. While we have taken back over most of the forecast operations, our service back-up office in Raleigh, NC, there may still be issues with delayed or missing products until all services are restored. No impacts to our core services of forecast products and weather watches, warnings and advisories are expected during this period. The forecast office in Blacksburg, VA will remain open and staffed through the period for public and partner phone calls. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...WP NEAR TERM...PM/WP SHORT TERM...DS LONG TERM...DS/WP AVIATION...WP EQUIPMENT...WP