465 FXUS64 KHUN 100818 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 318 AM CDT Tue Jun 10 2025 ...New NEAR TERM... .NEAR TERM... (Today) Issued at 318 AM CDT Tue Jun 10 2025 The most interesting weather in the near term will likely have ceased by the time the TN Valley wakes up to read this discussion. A weak surface front is currently bisecting the CWA providing just enough support for a weak line of showers and thunderstorms. Over the last several hours this line has slowly pushed from west to east in AL, weakening while doing do as the storms leave the more favorable CAPE and shear behind them in MS. Thus, this weakening trend is forecast to continue through daybreak with any lingering showers and storms existing into Central Alabama by sunrise. The moist environment will also support localized patchy to dense fog especially in areas not impacted by showers and storms. Any fog that does form will dissipate as the sun rises and winds pick up. The remainder of the day will be much more benign. Surface high pressure will work its way in behind the weak front and promote high and dry conditions. With light winds and mostly clear skies temps will easily reach the mid 80s. With afternoon dew points dropping into the low 60s to high 50s, humidity will remain manageable today making for a rather pleasant summer afternoon. && .SHORT TERM... (Tuesday night through Thursday night) Issued at 906 PM CDT Mon Jun 9 2025 Northwest flow aloft will weaken considerably on Tuesday night, with a low amplitude mid-level ridge predicted to build across the region on Wednesday/Wednesday night to the east of a weak but amplifying trough across the southern High Plains. This will yield a period of dry weather, as a surface high will remain centered across the southern Appalachians, providing light NE- light/variable winds and dewpoints in the u50s-l60s. Highs will be in the m-u 80s on Wednesday, bounded by lows in the l-m 60s Tuesday night and Wednesday night. During the period from Thursday-Thursday night, southwesterly flow aloft will become established across the forecast area within the gradient between a subtropical high centered off the southeastern Atlantic Coast and the southern High Plains trough (which will drift slowly east-northeastward across OK/TX). At the surface, light southerly winds will resume as the ridge to our northeast weakens over the southern Mid-Atlantic states, and this will allow dewpoints to climb back into the u60s-l70s. The related increase in CAPE, coupled with PWAT values rising back into the 1.6-1.8" range will support an increase in afternoon/evening showers and thunderstorms on Thursday, but with weak deep-layer flow and shear, convection will be unorganized and lightning/heavy rainfall will be the primary impacts. && .LONG TERM... (Friday through Monday) Issued at 906 PM CDT Mon Jun 9 2025 Data from the latest suite of global models suggests that deep- layer southwesterly flow will continue across the TN Valley throughout the extended period, as our region will remain along the northwest rim of a subtropical ridge retrograding across the FL peninsula and a slow-moving shortwave trough that will remain centered in the vicinity of the Arklatex through early next week. With precipitable values predicted to rise further into the 1.9-2.1" range by Friday evening (and remain in this range through Monday), a high spatial coverage of showers/thunderstorms can be expected each afternoon and evening, with potential for mainly outflow-initiated convection continuing through the early morning hours, as well. In the absence of synoptic scale lift and within an environment characterized by very weak flow, we expect highly unorganized updrafts that may still be capable of producing localized microburst winds on a daily basis given sufficient afternoon CAPE and low-level lapse rates. Thus, lightning and heavy rain/flooding will be the primary concerns, along with occasional strong winds. Highs will generally be in the m80s-l90s with lows in the u60s-l70s. && .AVIATION... (06Z TAFS) Issued at 1108 PM CDT Mon Jun 9 2025 A weak prefrontal sfc trough will continue to shift southeastward across northern AL overnight, providing sufficient lift to maintain an isolated coverage of SHRA/TSRA through 6-8Z at the terminals. However, due to the sparse nature of coverage, we will not include precipitation in the forecast attm. Otherwise, clearing skies, light winds and narrow dewpoint depressions will support development of BR/FG until a drier airmass slowly begins to spread across the region by sunrise, and MVFR vsby reductions have been included in a TEMPO group from 6-10Z. Sct high-based Cu will return by 15Z and should dissipate tomorrow evening, with sfc winds veering to NW and strengthening to 5-10 kts during this timeframe as well. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...RAD SHORT TERM....70 LONG TERM....70 AVIATION...70