Area Forecast Discussion
Issued by NWS Jackson, MS
Issued by NWS Jackson, MS
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049 FXUS64 KJAN 270003 AAA AFDJAN Area Forecast Discussion...UPDATED National Weather Service Jackson MS 703 PM CDT Sun May 26 2024 ...New AVIATION... .DISCUSSION... Issued at 211 PM CDT Sun May 26 2024 Through Monday: Warm and mostly dry conditions continue this afternoon as a mid level capping inversion keeps a lid on convective development across most of the area. However, later tonight a cold front currently extending from the Ozarks southward into the Red River valley will advance eastward toward the MS River overnight as a potent upper shortwave swings across the Midwest and TN Valley. These features may provide the needed forcing for convection to initiate and move into the upper ArkLaMiss Delta late this evening. While development may initially feature a few discrete cells, convection is expected to evolve fairly quickly into more of a line. It is with the earlier development, especially if things kick off a bit earlier in the evening than currently anticipated, where storms may be more likely to take advantage of steep mid level lapse rates and produce larger hail up to golfball size. This is also when there is some potential for a tornado to occur within modest low level helicity before the low level jet begins to pull north and eastward out of the area. As storms become more linear and cold pool dominant overnight, damaging wind gusts will become the prevailing threat with an even more limited brief tornado threat for any segments that can surge more eastward within marginally supportive 0-3 km bulk shear. Convection should lose intensity with time overnight as the cold pool outpaces the forcing. It is worth noting that recent CAM guidance casts some doubt over whether the forcing will be great enough to overcome the cap, which could considerably limit convective coverage tonight. Forecast guidance has increasingly trended toward the cold pool from overnight convection and/or outflows racing well south and eastward into our area tomorrow morning, acting in effect as a cold front by ushering in much drier air. This appears increasingly likely to limit rain chances during the day across most of the area once any showers clear early tomorrow morning. However, across south and east MS and central/south LA, there is greater potential for either the boundary to stall or retreat back into the area later in the day, keeping greater moisture and instability around. This will result in potential for isolated convection to redevelop Monday afternoon in these areas. Highly conditioned on whether such redevelopment does occur, any storms that redevelop in the afternoon could become severe given the potential for moderate to strong instability and marginally favorable deep shear. The window for this to occur appears to be quite narrow, with the threat dwindling toward sunset. Severe probabilities for the entire area during the daytime tomorrow have been adjusted downward accordingly. /DL/ Monday night through Saturday night: Isolated storms could linger into early Monday evening along/south of the Highway 84 corridor, but quiet conditions are expected for the most part. Looking ahead from mid/late week through the weekend, while the sensible weather over the forecast area will be slightly cooler, less humid, and more tolerable overall, this will not be reflected in the QPF as we will keep rain chances around just about every day. A deep trough digging southward over the eastern CONUS will generally keep the frontal boundary draped to our west and south, but with the upper level pattern expected to be progressive, a mid level ridge will build over the Plains to MS Valley region, and this will support a relatively moist deep layer airmass over our area. A couple of rounds of convective rainfall will possible in the late Tue to Wed time frame as a couple of minor perturbations move across in northwest flow aloft, but convective parameters do not look impressive at this point and this should help keep thunderstorm intensity below severe limits. Look for this weather pattern to persist through late week and the weekend. /EC/ && .AVIATION... (00Z TAFS) Issued at 659 PM CDT Sun May 26 2024 VFR conditions to start the period at all TAF sites. A few isolated SHRA or TSRA will be near KGLH, KGWO, and KGTR before 06Z, but main chance for any impacts from TSRA will be with possible storms moving north to south through the forecast area between the 08Z to 13Z time frame. An isolated shower or storm is also possible in far southern Mississippi after 18Z Monday. /NF/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 73 93 69 92 / 40 10 10 10 Meridian 74 94 67 93 / 60 30 10 10 Vicksburg 74 93 70 93 / 40 10 10 10 Hattiesburg 75 95 70 94 / 30 40 20 20 Natchez 72 93 70 93 / 30 20 20 20 Greenville 74 92 70 92 / 60 0 10 10 Greenwood 72 91 68 92 / 60 10 10 10 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ DL/EC/NF