####018005452#### FXUS64 KOHX 181910 AFDOHX Area Forecast Discussion National Weather Service Nashville TN 210 PM CDT Thu Apr 18 2024 ...New UPDATE... .UPDATE... Issued at 207 PM CDT Thu Apr 18 2024 At mid afternoon, skies remained sunny across Middle Tennessee. We are watching the start of a few cells just west of the Tennessee River near Savannah. Latest HRRR doesn't do much with these initial cells, but that may change if the cells do get established. Main focus is on well developed storms back over western Mississippi. We are still looking for this scattered storm activity to spread northeast into our area later on with peak coverage between 7 PM and 10 PM. Short range models continue to show good cape with a narrow axis of 2500 J/kg pivoting into our southwest counties toward 7 PM. Shear still looks marginal at best. So, we continue to expect a few instances of localized gusty winds and marginal sever severe hail with the early evening scattered storms. Later storms coming in from the west northwest after 10 PM will have better shear, so gusty winds and maybe a QLCS spinup tornado cannot be ruled out as the storms approach. But the late storms will weaken considerably as they push into our area and especially toward I-65. && .SHORT TERM... (Rest of today through Friday) Issued at 1157 AM CDT Thu Apr 18 2024 We started off cloudy this morning, but the clouds have been breaking up and we expect temps to take off into the low to mid 80s this afternoon. As temps warm, the atmosphere will destabilize with capes rising to 1000-2000 J/kg by late afternoon. This will set the stage for development of showers and thunderstorms. The first storms will form late this afternoon and evening as an impulse moves northeast from the Southern Ms Valley. This impulse will bring a first round of scattered thunderstorms starting as early as 3 PM in our western counties, with storms peaking in coverage and intensity from 7 PM to 10 PM. Later this evening, another batch of thunderstorms in the form of a weakening QLCS will come from the west ahead of a cold front. Each of these rounds of storms has the potential to produce severe wx, although latest models are not very impressive bringing shear and instability together. Generally, the greatest thunderstorm coverage and severe potential will exist west of I-65. It looks like the first batch will arrive with fairly strong cape but weak to marginal deep layer shear. A handful of warnings may bee issued for localized wind gusts over 60 mph and severe hail over 1 inch in diameter. Later in the evening, the instability wanes, but shear values will become higher as the QLCS approaches. Damaging wind gusts of 60 mph appear to be the main concern for late evening and overnight, but a tornado cannot be ruled out for our far northwest counties. The incoming band of storms may fall apart pretty quickly while encountering mediocre lapse rates and more stable surface air, possibly already worked over by early evening storms. Otherwise, a few spots may have some brief street flooding with any heavy downpours this evening. We don't expect widespread flooding problems. Showers and few leftover storms will move out Friday morning. We will be left with mostly cloudy and cooler conditions as a north breeze drops temps back to normal or a little cooler than normal. && .LONG TERM... (Friday Night through next Thursday) Issued at 1157 AM CDT Thu Apr 18 2024 Through the weekend, surface winds will continue to come from the north as the center of cool high pressure slides southward across the plains. Zonal flow aloft will bring a series of weak disturbances, resulting in a good deal of cloud cover through the weekend and perhaps a few light showers, mainly over our southern counties. Weekend temps will be a little cooler than normal. Temperatures will rebound Monday and Tuesday ahead of the next front and chance for showers late Tuesday into Wednesday. && .AVIATION... (18Z TAFS) Issued at 1212 PM CDT Thu Apr 18 2024 VFR conditions this afternoon with SCT to BKN clouds 030-050. Scattered thunderstorms develop mainly in western areas after 23z with a line of thunderstorms pushing into western areas after 05z. This line of thunderstorms will push east into the overnight weakening as it does. IFR/LIFR can be expected in any thunderstorms, gusty winds will also be possible in any thunderstorms. Low cigs will build in behind the line of thunderstorms and the low cigs will linger into tomorrow morning. Southerly winds today 6 to 12 knots becoming more westerly overnight. && .PRELIMINARY POINT TEMPS/POPS... Nashville 61 72 51 68 / 90 30 10 10 Clarksville 56 69 47 66 / 90 10 10 10 Crossville 60 70 47 64 / 80 60 10 10 Columbia 61 72 49 66 / 80 20 10 20 Cookeville 61 69 49 63 / 90 50 10 10 Jamestown 60 70 46 63 / 90 60 10 10 Lawrenceburg 62 72 51 66 / 90 30 10 20 Murfreesboro 61 72 49 67 / 90 30 10 10 Waverly 56 68 48 65 / 80 10 10 20 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE.......13 SHORT TERM...13 LONG TERM....13 AVIATION.....Mueller ####018004750#### FXUS62 KMFL 181911 AFDMFL Area Forecast Discussion National Weather Service Miami FL 311 PM EDT Thu Apr 18 2024 ...New LONG TERM... .SHORT TERM... (Rest of today through Friday) Issued at 1214 PM EDT Thu Apr 18 2024 The western Atlantic surface high continues to play the dominate roll in stable atmospheric conditions to wrap up the remainder of the week. As the high shifts eastward, the winds will veer and allow for a more distinct southeastward wind flow. With this assistance, it will allow for more tropical moisture and an increase in warm air. The warming trend will continue tomorrow afternoon with highs rising into the mid to upper 80s along the coasts with the potential for low 90s in the far SW interior. Far interior RH values will drop into the mid to upper 30%, but weak wind speeds should help keep the conditions from red flag/fire wx concerns. && .LONG TERM... (Friday night through next Wednesday) Issued at 241 PM EDT Thu Apr 18 2024 Mid level ridging will slowly start to break down as the weekend progresses. At the same time, a surface area of high pressure will continue to shift eastward in the Atlantic. This will allow for dry conditions to remain in place during this time frame. Winds will slowly become more southerly across the area as the weekend progresses allowing for moderating temperatures on Saturday and Sunday. Highs on Saturday and Sunday will range from the mid to upper 80s along the coasts to the lower 90s across the interior and Lake Okeechobee region. The weather pattern will start to change across South Florida early next week as a deepening mid level trough pushes across the Southeast and into the western Atlantic on Monday into Monday night. At the surface, a frontal boundary will push southeastward through Northern and Central Florida during the day on Monday. This front will be weakening as it pushes further south and this may cause it to stall out just to the north of the area or right over South Florida heading into Monday night and into the middle of the week. With the frontal boundary nearby, this may provide just enough lift to support a chance of showers and a slight chance of thunderstorms during this time frame. The highest chances of showers and storms still look to remain over the Lake Okeechobee region and Palm Beach County. With this being a rather weak front, uncertainty remains high in regard to the location of the frontal boundary stalling out and if it will remain in tact or not before actually getting to South Florida. A weaker frontal boundary will support lower chances of shower and thunderstorm development during this time frame. The latest forecast takes a blend of the forecast models and keeps a chance of showers and thunderstorms each afternoon across northern areas during the early and middle portion of the week. This will continue to be monitored as the week progresses. High temperatures will generally remain on the warm side as they will rise into the mid to upper 80s along the coasts and into the lower 90s across the interior sections. && .AVIATION... (18Z TAFS) Issued at 1214 PM EDT Thu Apr 18 2024 VFR conditions expected at all TAF sites. Breezy E/SE winds continue this afternoon and early evening hours with some gusts reaching 15 KT. A gulf breeze may develop around 18Z at KAPF bringing SW winds until 00Z. Light and variable winds at all sites overnight. && .MARINE... Issued at 1214 PM EDT Thu Apr 18 2024 The winds will remain southeasterly and weaken to wrap up the week as the surface high continues to shift eastward. Seas will generally remain 2 feet or less. && .BEACHES... Issued at 1214 PM EDT Thu Apr 18 2024 A moderate rip current threat will linger along the Atlantic beaches today with a diminishing trend to close out the week. && .PRELIMINARY POINT TEMPS/POPS... Miami 71 85 71 88 / 0 0 0 0 West Kendall 67 87 67 88 / 0 0 0 0 Opa-Locka 70 87 70 88 / 0 0 0 0 Homestead 70 85 69 86 / 0 0 0 0 Fort Lauderdale 71 84 70 85 / 0 0 0 0 N Ft Lauderdale 70 85 70 86 / 0 0 0 0 Pembroke Pines 70 88 70 88 / 0 0 0 0 West Palm Beach 67 86 68 87 / 0 0 0 0 Boca Raton 69 86 70 87 / 0 0 0 10 Naples 69 86 70 86 / 0 0 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && $$ SHORT TERM...Simmons LONG TERM....CWC AVIATION...Simmons ####018006158#### FXUS64 KEWX 181912 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 212 PM CDT Thu Apr 18 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (Tonight through Friday night) Issued at 207 PM CDT Thu Apr 18 2024 Clouds continue to scatter this afternoon ahead of a surface front to the north and a dryline to the west. This dryline will move into western Val Verde County this afternoon with the surface front reaching the northernmost portion of the CWA later tonight where it overtakes the dryline. Late this afternoon and evening, isolated thunderstorms may develop along both of these boundaries. Models indicate potential development over the higher terrain of Mexico late this afternoon and evening which could move into areas along the Rio Grande, although the better potential for storms in South Central Texas will be along the cold front. Storms will likely first initiate north of the area this afternoon in Central Texas. As the front continues south, thunderstorms may move into or initiate over the Hill Country and southern Edwards Plateau this evening. Steep mid-level lapse rates, upwards of 3000 J/kg of CAPE, and 30-40 knots of bulk shear will lead to a threat for severe storms this evening. Storm coverage should remain isolated to scattered with large to very large hail and damaging wind gusts the main threats. An isolated tornado also cannot be ruled out over the Hill Country. Storms may continue to move south into the Rio Grande Plains or portions of the I-35 corridor as the front sags across the CWA around midnight, although the majority of guidance does fizzle out any activity before reaching these areas. Expect a lull in activity overnight into Friday morning. The exact position of the front will play a big role in temperatures and precipitation chances tomorrow. Latest guidance indicates the front will be draped somewhere over the middle or southern half of the CWA during the afternoon. Went a bit cooler with temperatures tomorrow given the forecast position of this feature. The afternoon should be relatively dry with precipitation chances returning Friday night into Saturday, mainly for the western and northern portion of the area. Isolated to scattered storms may develop near this stalled front with the best chances in the west. && .LONG TERM... (Saturday through Thursday) Issued at 207 PM CDT Thu Apr 18 2024 The long term period will start out active, with a heavy rain event looking increasingly likely Saturday night, followed by several days of temperatures below normal, with Sunday being the coolest day of all. We start off with the meat and potatoes of the forecast: Saturday's heavy rain threat. The latest WPC Excessive Rainfall Outlook for Saturday night puts areas from the Edwards Plateau, through the Hill Country, the I-35 Corridor from Bexar County northward, along with the Coastal Plains mainly north of I-10 in a level 2 of 4 (slight) risk for flash flooding. Model guidance remains in fairly good agreement with the NAM12 being a bit of an outlier. For now, we will not put too much stock in the drier solution depicted by the NAM, but it is worth noting that the NAM does well with cold frontal passages. The NAM has the front moving through a bit faster than global models, hence undercutting storms as they develop along and out ahead of the boundary and push east. A shortwave in northern Mexico will team up with the cold front to initiate numerous showers and storms, and with surface dewpoints in the 60s and 70s ahead of the front, we won't have much of any trouble developing widespread showers and storms over the region Saturday evening. Rainfall amounts in excess of 1" are at 60-70% odds per the latest 13Z NBM over the majority of the slight risk area. Once the front shifts south of the CWA, we should see rain and storms come to an end before lunchtime Sunday. Beyond Sunday, the upper level pattern flattens out considerably, with zonal flow expected through the bulk of the upcoming week. Temperatures should slowly but surely moderate back into the 80s by Tuesday afternoon. There is an outside shot at some showers or storms Wednesday, but the threat remains quite low at this time. && .AVIATION... (18Z TAFS) Issued at 1220 PM CDT Thu Apr 18 2024 Many locations are still under MVFR ceilings early this afternoon, although conditions should improve to VFR around 19-20Z. Thunderstorms are likely to develop mid afternoon north of South Central Texas, but have the potential to move into the Hill Country and southern Edwards Plateau after 00Z. Confidence is still medium to low on how far south these storms can make it, but a few models do show showers or an isolated storm near the Austin area later tonight. Have included a TEMPO for TSRA at AUS, but have no mention of storms at other sites as confidence is too low to include. Low ceilings begin to redevelop across the entire area after 07Z Friday, likely lingering until a bit after 18Z. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 63 78 66 78 / 10 10 20 70 Austin Bergstrom Intl Airport 63 79 65 78 / 10 10 20 60 New Braunfels Muni Airport 64 79 66 80 / 10 10 10 60 Burnet Muni Airport 61 74 64 72 / 30 0 30 80 Del Rio Intl Airport 72 87 69 83 / 20 10 50 70 Georgetown Muni Airport 61 76 65 75 / 20 0 30 70 Hondo Muni Airport 66 84 65 81 / 20 10 20 70 San Marcos Muni Airport 63 79 65 79 / 10 10 10 60 La Grange - Fayette Regional 66 80 67 80 / 10 10 10 60 San Antonio Intl Airport 66 80 67 80 / 10 10 20 70 Stinson Muni Airport 68 82 68 82 / 10 10 10 60 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...27 Long-Term...MMM Aviation...27 ####018004684#### FXUS61 KILN 181913 AFDILN AREA FORECAST DISCUSSION National Weather Service Wilmington OH 313 PM EDT Thu Apr 18 2024 .SYNOPSIS... A low pressure system moves through the region, bringing showers and thunderstorms during the overnight hours into Friday. High pressure then moves in for the weekend, bringing below normal temperatures and the chance for frost early Sunday morning. Temperatures remain slightly below normal into the following work week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 700H wave moving through the larger flow will progress through the region this evening with its attendant surface low riding up from the Ozarks region. Congruent with previous thinking, a decaying MCS will move central Indiana into our CWA sometime late evening to around midnight. Severe threat looks pretty limited, given any residual daytime instability being pinched off earlier in the evening. However, some elevated instability may still be present and therefore cannot rule out an isolated strong to severe embedded storm making it into our western CWA. Should this happen, primary concern would be strong/damaging wind gusts, but it should also be noted that there will be /very/ subtle turning in the low levels, resulting in a non-zero tor threat (but pretty close). As the complex progresses east through the CWA it continues to weaken with the result that by the time it hits central Ohio during the early morning hours, we'll likely have something closer resembling a broken line of showers on radar reflectivity. Overnight low temperatures fall to the low 50s in west central Ohio and low 60s in southern Ohio. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... By Friday morning, the low pressure system will have moved off to the northeast and rain will be tapering to an end across the CWA. Quite a tight pressure gradient will be in place in the cold air advection regime, so expecting some gusty northwesterly winds around 15-20 MPH with gusts to 25-30 MPH, particularly in west central Ohio. Winds decrease as the day wears on. Surface high pressure nudges in from the northern Great Plains and some residual low level moisture remains, keeping partly cloudy skies in place. High temperatures reach the upper 50s in west central Ohio and upper 60s along the Ohio River/ Tri-State region. Friday night remains dry and cooler, with lows in the mid 40s area wide as the high pressure continues to nudge into the region. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Surface high pressure will shift southeast across the region Saturday through Monday. This will lead to dry but seasonably cool conditions. Highs Saturday and Sunday will be in the 50s to lower 60s, moderating a bit by Monday to highs in low to mid 60s. Some frost will be possible both Saturday night and Sunday night as overnight lows drop into the 30s. In northwest flow aloft, an upper level disturbance will move southeast across the region Tuesday into Wednesday. An associated surface low will move across the southern Great Lakes Tuesday night with a trailing cold front moving through the Ohio Valley. Ahead of this, showers will become likely Tuesday afternoon into Tuesday evening. Instability looks to be fairly limited, so only expect some lower chances for embedded thunderstorms. Highs on Tuesday will be in the 60s. High pressure and a drier airmass will settle into the area Wednesday into Thursday. Highs on Wednesday will be in the mid 50s to lower 60s with highs on Thursday mostly in the 60s. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... VFR conditions at all sites to start the period with high clouds beginning to encroach from the west. Clouds thicken and lower as the afternoon/evening continues ahead of the next low pressure system that will arrive during the overnight. Rain moves in around midnight; highest probability of thunder remains along the Ohio River, so have only included at the KCVG and KLUK TAF sites. CIGs lower to MVFR during the overnight into early morning hours with periods of reduced VSBYs. Conditions improve late morning on Friday. Winds pick up on the back end of the system, gusting to around 25 knots Friday morning into afternoon hours. OUTLOOK...MVFR ceilings/visibilities possible on Friday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...CA NEAR TERM...CA SHORT TERM...CA LONG TERM...JGL AVIATION...CA