Area Forecast Discussion
Issued by NWS Huntsville, AL
Issued by NWS Huntsville, AL
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330 FXUS64 KHUN 140103 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 803 PM CDT Mon May 13 2024 ...New NEAR TERM... .NEAR TERM... (Tonight) Issued at 802 PM CDT Mon May 13 2024 A quiet evening now in progress after any lingering drizzle or light rain ended late this afternoon. Temperatures are holding nearly steady in the middle 60s to near 70 with southeast wind of 5-10 mph at some locations, others less than 5 mph. We will be watching a 5h low just south of Kansas City and a trailing shortwave trough axis moving only eastward into central MO and AR by morning. UVVs will increase in advance of this wave, along with steepening lapse rates and moisture transport into the MS Valley. Showers and a few thunderstorms in southern MO and north and west central AR will advance east northeast tonight, but additional showers and thunderstorms are projected to develop in west TN, north MS and advecting into north AL and southern middle TN after 06-08Z. Our current forecast has this in mind, and will not adjust from it significantly. && .SHORT TERM... (Tuesday through Thursday) Issued at 135 PM CDT Mon May 13 2024 A fairly widespread coverage of showers and elevated thunderstorms will likely be in progress across the region around 12Z Tuesday, but should progress northeastward and out of the region by mid- morning. Subsequent breaks in the early morning stratus layer will allow for modest destabilization to occur late tomorrow morning, with additional (but more scattered) thunderstorm activity expected to develop to the west of our region (across western TN/northern MS) by 16-18Z. This activity should spread eastward through the TN Valley tomorrow afternoon, and will likely represent our greatest risk for strong-severe thunderstorms (warranting a Marginal Risk from SPC). The combination of mid-level WSW winds in the 35-45 knot range and MLCAPE perhaps as high as 1500-2000 J/kg in portions of the forecast area will favor organized convection, which may initially evolve as multicell clusters before growing into a broken line. Large hail/locally damaging winds and frequent lighting will be the main threats with this activity. Present indications are that afternoon convection will gradually weaken and spread eastward (out of the forecast area) early Tuesday evening, but with additional showers possible ahead of a surface trough (extending southward into our region from a low tracking through the OH Valley), we will maintain a low-medium chance POP region-wide through 6Z. A third and final round of showers (and perhaps a few storms) will likely occur on Wednesday with the passage of a weak cold front, but with a mid-level ridge likely to be crossing the region in the wake of the shortwave trough (noted above), storm coverage and intensity will be lower (compared to Tuesday). Clearing skies and calm winds are expected on Wednesday night as a narrow ridge of surface high pressure noses into the region from the north, and this may support the development of fog early Thursday morning as temps fall into the u50s-l60s. && .LONG TERM... (Thursday night through Monday) Issued at 342 AM CDT Mon May 13 2024 After brief upper ridging and surface high pressure that will keep rain out of the forecast on Thursday will come what seems like a "rinse and repeat" storm system (similar to the one discussed above) for Friday and into Saturday. Upper ridging will be pushed east as a trough makes its way over the Mississippi Valley through late week. At the same time, a surface low pressure system is shown to develop over southwestern Texas around midweek and then traverse to the northeast towards the ArkLaTex region by early Friday. Anticipating this system to continue its northeastward trajectory that will take it over northern Virginia, Delaware, and Maryland by Saturday morning. Chances of showers and storms are forecast to increase overnight into Friday morning. Unsettled weather will then likely persist through the weekend, with the highest chances (60-70%) of showers and storms anticipated Friday afternoon. While enough instability and shear will be present for thunderstorm development Friday afternoon and evening, the better upper dynamics and thermodynamics once again look to be to our south (much like the storm system in the near/short term). Overall, at this time, confidence in any severe weather is low because of this. However, we will continue to monitor this system in case the trajectory of the low tracks northward (increasing the severe potential). Highs will generally top out in the lower to mid 80s each day except for Friday (upper 70s) due to the increased coverage of showers and storms. Lows will remain in the lower to mid 60s through the weekend. && .AVIATION... (00Z TAFS) Issued at 553 PM CDT Mon May 13 2024 MVFR ceilings will continue into the night. After 0Z, light showers will begin to impact the area further lowering ceilings and visibilities. The most likely timeframe for heavier showers impacting terminals is 12-16Z. Confidence is low in seeing thunder with these showers and thus it was not included in the TAF. After 16Z vicinity showers will likely clear for a few hours with potential for brief VFR conditions. After 18Z isolated thunderstorms will be possible throughout the area and could impact each terminal through the duration of the TAF period. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...17 SHORT TERM....70 LONG TERM....26 AVIATION...RAD