Area Forecast Discussion
Issued by NWS Jackson, MS
Issued by NWS Jackson, MS
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633 FXUS64 KJAN 061643 AAB AFDJAN Area Forecast Discussion...UPDATED National Weather Service Jackson MS 1143 AM CDT Mon May 6 2024 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE... Issued at 1126 AM CDT Mon May 6 2024 Daytime mixing and heating is underway, with earlier morning cloud cover having mixed out across most of the forecast area to scattered cumulus deck. Analyzed SBCAPE values are already in the 2500 J/kg range or greater, but a shortwave ridge passing overhead the Mississippi River Valley at this current hour will actively suppress convection for the next few hours. A shortwave trough however is apparent over East Texas on water vapor satellite imagery, and as the ridge passes east this disturbance will add a boost of lift and slight increase to deep layer wind shear across the area this afternoon. The expectation is for isolated to scattered showers and thunderstorms developing first across central/northern Louisiana and perhaps southeast across southern Mississippi where moisture availability is greater. An isolated stronger storm could develop, but organized severe weather is not expected at this time. /NF/ && .DISCUSSION... Issued at 406 AM CDT Mon May 6 2024 Today through tonight: A convective outflow boundary, currently perched just north of the forecast area from eastern AR into northern MS, should become increasingly diffuse this morning as a weak shortwave trough exits the region to the east and boundary layer mixing increases with daytime heating. Patchy areas of morning fog will dissipate early, and this will be followed by very warm daytime temperatures. Otherwise, a moist and unstable airmass should support isolated to scattered afternoon and early evening showers and storms. Relatively quiet conditions are expected overnight with surface wind likely a bit too strong for getting much fog. /EC/ Tuesday through Monday: Early morning global guidance continues to highlight a 985 mb surface low pressure system wobbling over the Northern High Plains as mid-level shortwave trough axis pushes northeastward towards the Great Lakes Region by late Tuesday morning. As this trough makes its way towards the Great Lakes, a cold front will develop ahead of the trough axis and track south towards the southeast US. Because of this, storm chances will begin to increase across central MS heading into Tuesday afternoon. With southerly flow aloft increasing the influx of sufficient moisture flow from the Gulf, over 2400 J/kg of MLCAPE, PWATs above 1.50 inches, and the interaction of disturbances aloft interacting with the hot and humid airmass at the surface, the environment appears favorable for strong to severe thunderstorms across the region. A Marginal Risk for isolated severe storms currently exists through Tuesday evening mainly for areas along and north of the Hwy 82 corridor and extreme northwestern ArkLaMiss Delta, and the Storm Prediction Center has extended the marginal risk further south to include the eastern half of the I-55 corridor. Primary hazards with these storms will be damaging wind gusts and hail up to quarter size. The severe threat will continue heading into Wednesday/Thursday as the frontal boundary pushes further south across central MS. Given the favorable parameters for this timeframe, we will continue to advertise a Slight risk for severe weather in our HWO graphics. Furthermore, the westerly flow, increased wind shear, and high moisture content will lead to several storms producing locally heavy rainfall at times, thus localized flash flooding will be a concern at times. There is uncertainty that remains in regards to how further south the frontal boundary will setup in our CWA heading into late Wednesday night and early Thursday, so confidence in the severe weather/heavy rain threat beyond then is low. Any thunderstorm chances will come to an end Friday as the frontal boundary surges further south out of our forecast area. Heading into the weekend, a 1020mb sfc high will develop in the ArkLaTex region before slowly pushing east towards our CWA. This will allow for quiet weather to settle across the south with cooler-than-normal temperatures expected. Some scattered to isolated showers and storms will be possible heading into Monday. /CR/ && .AVIATION... (06Z TAFS) Issued at 122 AM CDT Mon May 6 2024 Have maintained forecast for low stratus and potential fog through early morning in this persistent, warm/humid, southerly flow pattern. The greater threat for LIFR category ceilings/vsby will be over southeast portions of the area, but all sites should observe sub- vfr conditions until mixing brings improvements later in the morning. VFR conditions should prevail Monday aftn/evng at all sites. /EC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 87 69 87 71 / 20 20 30 0 Meridian 89 66 89 69 / 30 20 50 10 Vicksburg 88 69 87 71 / 20 20 20 0 Hattiesburg 89 68 88 71 / 20 20 30 0 Natchez 87 68 87 71 / 40 20 20 0 Greenville 87 72 86 72 / 20 20 20 10 Greenwood 87 70 86 71 / 20 20 40 10 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ NF/CR/EC