####018006764#### FXUS64 KHUN 160201 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 901 PM CDT Thu May 15 2025 ...New NEAR TERM... .NEAR TERM... (Rest of tonight and Friday) Issued at 900 PM CDT Thu May 15 2025 A closed low continues to move eastward into the Great Lakes region as high pressure exists in the Gulf, allowing the Tennessee Valley to be encapsulated in an area of moderately strong mid level flow between the two systems. A strong LLJ (~40 kts) is forecast to move into the region overnight, with higher forcing to our NW. Assisted by WAA, there could be some shower development from what is left of a lingering MCS earlier this evening as it continues southeastward near our area. Primary timing for showers would be between 4-7 AM. While we continue to be outlooked by SPC for a low chance of strong to severe storms through 7 AM, we continue to have low confidence in any thunderstorms materializing. Low level lapse rates are weak and we are influenced by a capping inversion. Therefore, we are advertising a very low chance of a strong storm tonight with the potential for gusty winds up to 30-40 mph. However, the WAA should keep lows relatively warm as temperatures only drop into the low to mid 70s. Friday, dry weather returns for most of the day as high temperatures warm into the mid to upper 80s. Gusty, southwesterly winds up to 20-25 mph are forecast as an increased low level jet moves into the area and begins to mix down. We will be monitoring a low-medium risk for strong to severe storms Friday night into Saturday morning, however, more on that in the short term section below. && .SHORT TERM... (Friday through Saturday night) Issued at 1131 AM CDT Thu May 15 2025 Current short range model solutions suggest that multiple small convective clusters (north of our CWFA) will continue to spread generally east-northeastward and into the central/southern Appalachians after 12Z Friday, but may continue to impact our southern TN counties through 15Z, warranting a low (15-20%) POP. Although this convective regime will largely dissipate by late Friday morning, a remnant mesoscale differential heating or outflow boundary may serve as a focus for redevelopment of thunderstorms across southwestern MO/northwestern AR by mid-day. Present indications are that the intermediate portion of the moisture gradient boundary/remnant dryline (extending from the western Ozark Plateau into southern IN) will lift northward throughout the day as a distinct mid-level vort max (peripheral to the larger closed cyclone aloft) tracks eastward from eastern CO into northern MO, with development of supercells expected across a broad portion of the open warm sector tomorrow afternoon from southeastern MO/northeastern AR eastward into the central OH Valley/northwestern TN. The supercell regime will continue to spread eastward into the Cumberland Plateau region early tomorrow evening, but may also clip a portion of northwest AL/southern TN, with an increasing risk for severe wind/hail and tornadoes in this region perhaps as early as the 2-4Z timeframe Saturday. However, it still appears as if our primary severe weather event will occur with an MCS that will initiate from extensive convection over the Lower OH Valley early Friday evening and spread southeastward with time, reaching the northwest portion of the CWFA between 4-6Z. Upon initial arrival in our region, the MCS will feature a risk for severe wind/hail and perhaps a couple of brief tornadoes, as WSW flow aloft of 55-65 knots will be favorably aligned with a 40-50 knot WSW low-level jet for an extended period from late Friday afternoon-early Saturday morning. However, with time, the MCS will gradually lose intensity as it spreads southeastward, exiting the forecast area by 10-12Z. Lingering light rain may continue for a couple of hours after 12Z Saturday (especially south of the TN River), but extensive convective outflow in the wake of the MCS will surge southward, focusing any redevelopment of afternoon thunderstorms on Saturday from northern MS southeastward into central AL/GA. As a shortwave disturbance lifts northeastward across the southern Rockies on Saturday, surface pressures will begin to fall across eastern NM/TX Panhandle, with the remnant outflow boundary predicted to retreat northeastward on Saturday night. This may result in increasing probabilities for elevated convection across our region in the 3-9Z timeframe Sunday in the presence of weak elevated CAPE. && .LONG TERM... (Sunday through Wednesday) Issued at 931 PM CDT Wed May 14 2025 A rather flat 5h pattern over the southeast U.S. will become more amplified from Sunday into Tuesday. An upper ridge will amplify and shift east into the Great Lakes south to the Gulf Coast. A longwave will follow into the Plains states and deamplify upon reaching the MS River Valley Tuesday and Tuesday Night. The residual surface outflow from convection on early Saturday will lift northward Saturday night into Sunday, keeping low to medium chances of MCS or at least scattered convective development in play. As the Plains surface cyclone emerges into KS/NE on Monday into Monday night, the boundary will lift northward with thunderstorm chances decreasing. The low will reach the upper MS valley on Tuesday night, with a trailing cold front into AR/LA. Low chances of thunderstorms will spread east into the region Tuesday into Tuesday night as a result. Warm advection will increase substantially through early next week at the surface thru 8h as a south-southwesterly low level jet increases across the entire Gulf state region northward ahead of the trough/cold front. 8h temperatures should warm back into the mid to upper 10s. Surface high temperatures will be in the lower 80s Sun, lower to middle 80s Mon, and middle to upper 80s Tue and Wed. Lows will be mainly in the 60s during this period, but could be as warm as 70 Tuesday morning. && .AVIATION... (00Z TAFS) Issued at 503 PM CDT Thu May 15 2025 VFR flight weather conditions are forecast at both KMSL and KHSV. However, there is a low chance of TSRA clipping far northwest AL and southern middle TN between 03-10Z. Another complex of TSRA may also affect areas north of AL and southern middle TN after 12-14Z. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...HC SHORT TERM....70 LONG TERM....17 AVIATION...17 ####018006953#### FXUS61 KBGM 160201 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 1001 PM EDT Thu May 15 2025 .SYNOPSIS... Unsettled weather with multiple rounds of showers and thunderstorms will persist through Saturday. Cooler weather with a few lingering showers is expected to round out the weekend on Sunday, before dry and cool weather arrives for the beginning of next week. && .NEAR TERM /THROUGH FRIDAY NIGHT/... 950 PM Update... The shower activity has tapered off across much of the area and skies have started to clear. There are some pockets of fog beginning to develop, so did add in some patchy fog for tonight through early tomorrow morning, although with increasing clouds ahead of a morning round of showers and thunderstorms, much of the fog may be through around 08-09Z. The CAMs were a bit slower with the arrival with the morning convection, so did slow down the eastward progression after 10Z. The rest of the forecast remains on track at this time. 345 PM Update: As an upper level trough axis is moving through this afternoon, isolated showers and thunderstorms have developed. These thunderstorms have been on the weaker side with somewhat limited instability and very little shear. That being said, with a weak steering flow present, these showers and thunderstorms have been on the slow moving side. As a result, while flooding has not been an issue so far, there is still a possibility for some isolated instances of flash flooding. The scattered showers and slow moving isolated thunderstorms quickly diminish this evening, with dry weather expected for most of the overnight. Stratus clouds and patchy fog are likely to develop once again. A decaying MCS/QLCS quickly approaches from the west late at night into early Friday morning; likely reaching Steuben/Bradford counties around daybreak. This line should be weakening as it rolls through due to limited instability in place. It will be mild overnight with lows in the mid-50s to lower 60s. The weakening line of showers and isolated thunderstorms quickly moves east across most of the forecast area Friday morning. After this initial morning convection, conditions should dry out and clouds break for partly sunny skies heading into the afternoon and evening hours. Additional scattered showers and thunderstorms will likely develop in the afternoon along a cold front. However there is some question on how dry mid level air and capping could limit convective development. Otherwise, Friday will be rather warm and humid with highs in the upper 70s to mid- 80s and surface dew points in the low to mid-60s. Coverage of showers and thunderstorms will diminish Friday night with very brief weak ridging building in and the loss of diurnal heating. Lows are expected to be mainly in the 60s. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... 300 PM Update... Warm front moves through the region Saturday morning bringing a round of scattered showers and thunderstorms to the region. Showers will move from west to east making an exit by early afternoon. The timing of the initial round will suppress/lack instability, model sounding show a cap in the morning hours. Once the showers move through skies attempt to clear behind allowing for some afternoon heating. Temperatures will be warm with highs climbing into the mid to upper 70s with some spots in the low 80s in northeast PA. NAM sounding shows CAPE values ranging 1,000 to 1,500 J/Kg with 30-35 knots of bulk shear. The cap is not expected to break until the afternoon hours when a cold front moves through. This will set off a second round of showers and storms with more potential to produce isolated strong to severe storms. SPC has upgraded most of our region to a slight risk with a fraction of our western region still in a marginal risk. Otherwise the frontal system moves out of the region Saturday evening, with showers and thunderstorms ending with its departure. A brief dry period follows overnight with temperatures in the upper 40s to mid 50s. Upper level low continues to rotate as it moves east with wrap around moisture allowing showers to linger into Sunday. Model guidance has slight variations of the placement of the low keeping showers mainly in central NY. Although showers may also extend into northeast PA as well. Temperatures on Sunday will be cool behind the front with highs climbing into the upper 50s to upper 60s. Showers will dissipate Sunday night with drier conditions settling in. Overnight lows will fall into the low to upper 40s. && .LONG TERM /MONDAY THROUGH THURSDAY/... 300 PM Update... Cool pattern continues into the start of the week with northwest flow in place along with an upper level ridge building in. Dry conditions will finally hold Monday with high pressure building in at the surface. Skies will clear out by the afternoon with temperatures in the mid 50s for most of the region with some areas in northeast PA reaching the mid 60s. Similar cool and dry conditions are expected on Tuesday with a system passing just to our south. While the next round of showers is not expected until Wednesday, there is some uncertainty on the timing and ensemble, regardless NBM guidance still supports a slight chance PoPs. Uncertainty continues towards the end of the period but model guidance hints at another chance for showers Thursday. Otherwise temperatures remain cool during this period with highs in the low 50s to upper 60s. Overnight lows will fall into the upper 30s to upper 40s with some patchy frost may be possible Monday night. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Mainly VFR conditions will be present most of this evening, with isolated showers and thunderstorms starting to dissipate as the sun sets. Overnight tonight, some low stratus will be present, which will result in at least MVFR to Fuel Alternate ceilings. Conditions likely return to mainly VFR by late Friday morning, although there will still be some showers around. PROB30 groups for thunderstorms were added for RME and SYR between 15-21Z, but confidence is currently low for exact timing, and if lightning even develops, but the highest current likelihood is for those two terminals. Showers elsewhere in the early to late morning. Outlook... Friday afternoon through Sunday...Scattered rain showers and isolated thunder possible, along with associated restrictions. Sunday night through Tuesday...Mainly VFR expected. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...BJG/MJM NEAR TERM...BJG/DK SHORT TERM...ES LONG TERM...ES AVIATION...KL