Area Forecast Discussion
Issued by NWS Jackson, MS
Issued by NWS Jackson, MS
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488 FXUS64 KJAN 231451 AFDJAN Area Forecast Discussion National Weather Service Jackson MS 951 AM CDT Sun Jun 23 2024 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE... Issued at 951 AM CDT Sun Jun 23 2024 Increasing heat stress across the region will be the primary concern for today. Morning model consensus continue to show high pressure aloft over the southeast CONUS. This will keep weather conditions quiet over our forecast area today. Later in the afternoon, the high pressure aloft will begin to slowly shift west of the region, allowing for northwest flow to setup across our CWA. At the surface, south to southwest flow across the region will result in increasing moisture and heat across our forecast area this afternoon. With generally clear skies across the region this morning, daytime heating will allow for afternoon highs to peak into the mid to upper 90s across central MS. With heat indices reaching in the 102 F - 107 F deg range across the area, a Heat Advisory remains in effect from noon today until 8 pm this evening, mainly for portions of west MS along with all of our Northeast LA parishes, and our Southeast AR counties. /CR/ && .DISCUSSION... Issued at 303 AM CDT Sun Jun 23 2024 Today and Tonight...High pressure aloft will overall remain in control of the weather across the region through much of the period. While this high aloft drifts further west of the region, northwest flow aloft will setup across the forecast area. Meanwhile at the surface, south to southwest flow across the region will result in increasing moisture and heat across the CWA today. With the mid/upper level high center drifting further west overnight, its weakening presence over the region will allow a weak frontal boundary to sink south into the forecast area around day break Monday. This will also allow for some isolated showers to dot skies over far northern portions of the CWA at the end of the period early Monday morning. Otherwise, with increasing clouds overnight into Monday morning, expect mild lows as they range from the mid 70s to around 80. The bigger story during the period will be the increasing heat stress across the region this afternoon. As eluded to above, moisture will be on the increase across the area today, especially across western portions of the CWA where dew points will reside in the low and middle 70s as highs climb into the upper 90s. This level of heat and humidity will result in afternoon heat index values between 105-110 degrees. As a result, the "Heat Advisory" that was initially in effect for northwest portions of the Delta, will be expanded to cover portions of West Mississippi and all of our Northeast Louisiana parishes. Elsewhere, the combination of highs in the mid and upper 90s and dew points in the mid 60s to around 70 will yield heat index values near 105. /19/ Monday and Tuesday: With generally southerly low level flow, moisture will continue to increase across the area Monday. Meanwhile, with the mid/upper ridge retracting westward, a weak surface front will slip into northeast MS, stalling through the day. Isolated showers will be possible ahead of this feature as early as Monday morning, with greater coverage possible by afternoon with the aid of daytime heating. It is possible slightly drier air with the front may sneak into the Golden Triangle, but most areas will see dewpoints in the 70s through the day. A similar regime will prevail Tuesday, with rain chances mainly following driven by diurnal instability, though stray showers couldn`t be ruled out any time of day given the abundantly moist airmass. Outside of the rain and clouds, it will be very hot with temps in the upper 90s to around 100 each day. Unfortunately, with the humid conditions expected, this will result in heat indices meeting or exceeding critical thresholds in most areas. It is likely the Heat Advisory will need to be expanded both in time and area for Monday and Tuesday. Wednesday and Thursday: With the upper ridge temporarily retreating, there will be perturbed NW flow aloft, which along with PW surpassing 2 inches at times, will provide the ingredients for greater coverage of convection on Wednesday into Thursday. Clouds and rain will be more likely to limit daytime temperatures than on previous days, but in any areas where clouds/rain are limited, heat stress may continue to be an issue with heat indices still potentially reaching dangerous thresholds. Upper ridging will begin to build eastward again on Thursday, and this will begin to limit rain chances across AR/north LA/northwest MS. Friday and Saturday: The upper ridge will continue to build over the area, with temperatures trending back upward. The seasonably moist airmass will remain, fostering mainly diurnal convection each day. Additionally, heat stress concerns will continue to be in the picture outside of relief from any rain. Not that there was any doubt before, summer is here. /DL/ && .AVIATION... (12Z TAFS) Issued at 619 AM CDT Sun Jun 23 2024 VFR flight categories will prevail at area TAF sites over the next 24 hours. Winds will increase late this morning, becoming west southwesterly between 5-8 knots. /19/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 95 76 96 77 / 0 10 20 10 Meridian 98 75 99 74 / 0 10 20 10 Vicksburg 96 77 96 76 / 0 10 20 0 Hattiesburg 98 76 98 76 / 0 0 40 10 Natchez 95 75 96 76 / 0 10 20 10 Greenville 98 78 99 79 / 0 10 10 0 Greenwood 97 76 99 76 / 10 10 10 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...Heat Advisory until 8 PM CDT this evening for MSZ018-019-025-034- 035-040-041-047. LA...Heat Advisory until 8 PM CDT this evening for LAZ007>009-015-016- 023>026. AR...Heat Advisory until 8 PM CDT this evening for ARZ074-075. && $$ 19/DL/19