textproduct: Jackson

KEY MESSAGES

- Periods of heavy rainfall and flash flooding will be possible throughout this week.

MESOSCALE UPDATE

Issued at 747 PM CDT Mon May 25 2026

Deep tropical moisture advection continues across the Gulf Coast region this evening. Satellite imagery shows the meridional moisture transport, with a plume of moisture extending from the Yucatan Peninsula into the Mid-South, and the spin of an upper- level low pressure system centered over East Texas. The surge of moisture transport and earlier MCV activity has shifted to the north of our area, but broad cyclonic flow can still be seen in regional radar mosaics. Slow-moving showers and storms through overnight could cause a localized flash flooding threat, but the next primary focus for heavy rainfall will be with the return of daytime heating tomorrow. The deeper moisture plume over eastern Mississippi will again focus the greater heavy rain threat in those areas. MRMS estimates of rainfall from today's MCVs show a swath of 2-5 inches of rain fell in our area from southern Lamar/Forrest counties to Lowndes County in eastern Mississippi. So any additional heavy rain would quickly run off in those areas and lead to flooding. An "Elevated" threat for flash flooding has been included in the local Hazardous Weather Outlook graphics for eastern Mississippi. The rest of the area remains under a "Limited" threat for a more isolated potential of heavy rainfall.

Extended the mention of a "Limited" threat for flash flooding areawide through Friday due to moist environment and areas of saturated ground. /NF/

DISCUSSION

Issued at 158 AM CDT Tue May 26 2026

This week into weekend through early next week (Monday)...

Today into tonight: Upper low remains parked to our west, keeping broad cyclonic/southerly return flow into the Gulf Coast states. GOES east total precipitable water (PWs) indicate nearly 2 inch PWs mainly east of the MS/AL border while around an inch and half PWs or so along and west of the Interstate 55 and MS River corridors. This is a result of less return flow air (generally southeasterly flow around 850-700mb), but will gradually change into the afternoon. As the upper low lifts northward, southerly return flow will lock in the afternoon hours, leading to efficient moist advection (PWs generally in the 1.75 to 2 inch range, 850mb Theta E around 335K, strengthening cloud bearing layer flow in the 850-300mb layer flow to around 30ks and light southwesterly backbuilding vectors under 15kts). This pattern, combined with wet antecedent conditions, lead to elevated flash flooding risk. Neighborhood HREF PMMs (10 percent) for exceeding 3 inches and HREF max values (3 to 5+ inch amounts in the Pine Belt), support continued "Elevated" messaging in HWO graphics. Many convective allowing models in the HREF suite, indicate reasonable rainfall totals (1 to 3 inches) and worst case rainfall totals (3 to 5 inches). With recent rains and issues in this area and any additional rain/MCV influence, messaging "Elevated" for flash flooding in the HWO fits. Weather Prediction Center (WPC) has continued to highlight a "Slight" risk for heavy rain, with higher confidence of concerns in the Interstate 59 corridor that was hit hard yesterday. Highs will be seasonably cool this afternoon (79F to 82F in the Interstate 59 to Highway 45 corridors to 83F to 85F to the northwest) while seasonably warm lows this morning and again tonight (67F to 69F this morning and 68F to 72F tonight). Rain chances remain highest (70 to 95 percent) southeast of the Natchez Trace, while lower along and northwest (45 to 70 percent).

Wednesday through next Monday: As this upper low lifts northward, there will be continued southerly flow but lighter through the week. The region will be gradually caught in a longwave quasi- omega block pattern into mid to late week (upper low caught over the Pacific states and developing longwave trough over the northeast states into eastern Canada). However, this synoptic pattern doesn't look as established as a typical omega block, with strong subtropical ridging established over the western Atlantic extending westward into the FL Peninsula. On the eastern periphery of the western portion of the quasi-omega block will be another piece of perturbed energy/vort max that will cutoff over the TX Panhandle Wednesday into Thursday. This will keep light return flow but deep moisture near 2 inch PWs through late week. Rain coverage will remain high through the work week (55 to 90 percent daily) with some days on the higher end of the range than others. Keeping a "Limited" going through the work week as wet antecedent conditions and mesoscale features, such as local MCV influence, will be need to be evaluated on a daily basis.

As the upper lifts and shears out across the Mid South to Mid MS Valley into the weekend, westerly flow will lock in, leading to less moist Gulf influence and more scattered rain and storm coverage (45 to 80 percent Saturday and 35 to 55 percent Sunday). Highs remain seasonably cool this week (low to mid 80s) while generally seasonably warm lows (upper 60s to low 70s). Longer range pattern may consist of surface high diving into the Great Lakes and eventual drying front from the north, helping coverage to become more scattered to isolated and continued seasonable cool conditions into early next week. /DC/

AVIATION

(00Z TAFS) Issued at 747 PM CDT Mon May 25 2026

A mix of VFR to IFR conditions to start the period due to low stratus. Most rain has ended in the forecast area for the time being, but stray heavy rain showers possible until more widespread activity develops around 18Z Tuesday. /NF/

PRELIMINARY POINT TEMPS/POPS

Jackson 82 70 85 70 / 70 20 80 60 Meridian 80 70 85 70 / 80 30 80 50 Vicksburg 84 70 85 70 / 60 20 90 70 Hattiesburg 81 71 85 70 / 100 30 80 50 Natchez 84 71 85 71 / 70 30 80 70 Greenville 84 69 85 70 / 50 30 50 70 Greenwood 84 69 86 70 / 50 40 50 50

JAN WATCHES/WARNINGS/ADVISORIES

MS...None. LA...None. AR...None.