Area Forecast Discussion
Issued by NWS Jackson, MS
Issued by NWS Jackson, MS
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372 FXUS64 KJAN 210554 AFDJAN Area Forecast Discussion National Weather Service Jackson MS 1254 AM CDT Tue May 21 2024 ...New AVIATION... .MESOSCALE UPDATE... Issued at 949 PM CDT Mon May 20 2024 It was another hot afternoon as many sites topped out in the lower 90s. As a result it has taken a little longer to cool down and temperatures were running a couple degrees warmer than anticipated. Morning lows still look on track and there could be some light patchy fog in the southeast. No significant changes were needed. /22/ && .DISCUSSION... Issued at 217 PM CDT Mon May 20 2024 Through midweek (Tonight-Wednesday night)... Tonight-Tuesday: As the mid-level ridge axis builds northeast from the Bay of Campeche & Mexico, the low-level ridging & thermal capping will increase across the Gulf Coast states. Sfc & thermal ridge will be centered over the Carolinas to Atlantic seaboard, while return southerly flow will pick up across the Gulf Coast to Mid South region. Longwave pattern will consist of deepening shortwave/strong sfc low pressure system moving into the Mid West. Building 593-595DM ridge over Bay of Campeche & Mexico will deflect any concerns well off to the northwest through Tuesday. Thermal capping is expected with 10-12 deg C range 700mb temps & PWs only in the 1-1.25 inch range, with dry 850-700mb RH`s in the 30-40% range. This will suppress any convection chances & lead to a dry & warm pattern. For tonight, expect a dry night but WAA & some crossover temps in the Pine Belt from advection of upstream Gulf moisture could lead to some patchy to even patchy dense fog. Added an "Limited" for isolated cases of patchy dense fog. HREF probs support even increased messaging & more expansive areal configuration in HWO graphics. Going with most confident area in an area along & southeast of a line from Brookhaven to Mendenhall to Bay Spring. Thermo pattern in the mid-upper teens to low 20s degree C at 850-925mb layers support continued seasonable warmth in the upper 80s to low 90s Tuesday aftn & possible a site could again peak in mid 90s. Heat stress won`t be a concern but increased humidity will aid in heat indices climbing into low-mid 90s. Seasonably warm lows are expected tonight & Tuesday night, in the mid 60s southeast of the Natchez Trace to upper 60s-low 70s. Patchy fog to even patchy dense fog can`t be ruled out again Tuesday night but keeping out of the HWO graphics for now. Wednesday: As the strong trough/low pressure system eject into Great Lakes-southern Canada, height falls are expected on the northern extent of the subtropical ridge across the Mid South to Gulf Coast States. This will be along a frontal system sagging across these zones & extending northeast into the OH Valley to Mid Atlantic states. Southerly return flow of warmth & moisture will persist, with thermal profiles still supportive of some capping while some relaxation in the Hwy 82 corridor & northwest of the Natchez Trace. Seasonably warm highs into the upper 80s to low 90s & lows in the mid-upper 60s to low 70s Wednesday night again are expected. Increased moist ascent support isolated rain & storm chances into the extreme northwest ArkLaMiss Delta. In these areas, if some storms could sneak in, there is enough deep shear >40kts & lapse rates/vertical totals in the 25-27 deg C range for a low end threat of isolated strong-severe storms, so leaving HWO graphic as is. /DC/ Thursday into early next week... As we go into late week, the ridge will get flattened and we will see a more quasi-zonal regime get established followed by a potential NW flow pattern for Sun-Tue as a more substantial large scale trough sets up across the E CONUS which looks to eventually push a cool front and dry air into the area by middle of next week. The sensible weather from this evolving pattern supports warmth and increasing humidity. Low level temp anomalies are on the (+) side and we will reside in the 90th to 97th percentile of 850mb temps. We should see quite a bit of 90-95 degrees for MaxT. MinT will be above normal as well and mostly in the upper 60s to lower 70s before we see more lower 70s by the weekend and ahead of any boundary next week. Other concerns will be for an active storm period potentially. By no means is this locked in, but such an active zonal flow pattern with multiple decent waves moving through from Thu into early next week should support at least one day of decent storms if not a couple. Northern areas seem more prone from Thu-Sun as this area is closest to the source region and any MCSs coming from the S Plains. These are always low predictability situations and will need to get closer to those days to get a better handle on things. Early week, ahead of the main cool front, would offer at least one opportunity for most of the area to see some stronger activity. This is still in the 6-8 day realm, so we have plenty time to watch. /CME/ && .AVIATION... (06Z TAFS) Issued at 1250 AM CDT Tue May 21 2024 VFR conditions will prevail for the most part along with gusty southerly winds during time of peak heating. Patchy areas of IFR category BR/FG will be likely in the PIB/HBG area during the early morning. Any fog/stratus should dissipate by mid morning. /EC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 68 88 69 89 / 0 0 0 10 Meridian 67 90 67 91 / 0 0 0 0 Vicksburg 70 89 71 90 / 0 0 10 10 Hattiesburg 67 90 67 91 / 0 0 0 0 Natchez 69 88 69 90 / 0 0 0 10 Greenville 73 89 72 89 / 0 10 20 20 Greenwood 71 90 71 90 / 0 10 10 20 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ DC/CME/EC