textproduct: Jackson

KEY MESSAGES

- Scattered showers and some storms are expected across the area late this afternoon into tonight. Outdoor plans may proceed without disruption, but have a backup plan in case of rain.

- The chance for showers and thunderstorms is increasing Tuesday into Wednesday. We are monitoring potential for some storms to be strong to severe.

- Heavy rainfall is possible during both systems. We will have to monitor for isolated flash flooding.

DISCUSSION

Issued at 1247 PM CDT Sat Oct 31 2026

Through next week (Friday)...

Today and Sunday: Shortwave is analyzed today over the ArkLaTex to MS River Valley. This is leading to widespread moist isentropic ascent and overcast conditions across the Gulf Coast states. There is some uptick in deep moisture (PWs in the 1.3 to 1.6 inch range) but we are dealing with some dry air pockets (depicted as "onion" shape in morning 12Z soundings to areas: 700-500mb layer and surface to 850mb layer). This will take some seeder-feeder mechanisms to moisten the dry air layers aloft, which in turn will lessen the actual observation of rain early on in the forecast period. Based on that, rain chances may be scattered or even higher than before, but actually observing rain or any heavier downpours, with limited insolation, will be much harder to come by. The main takeaway is that even though rain chances are in the medium to high chance range (40 to 80 percent), it will take some continued and efficient isentropic ascent to overcome some of the earlier mentioned failure modes. With such dry antecedent conditions and severe to exceptional drought over a large portion of the Gulf Coast region, any rain will be helpful. However, not anticipating much drought improvement with this rainfall.

The only areas that convective allowing models (CAMs) indicate some heavier downpour potential is the axis of slightly deeper moisture projected to advect into southeast MS into the Highway 45, Highway 98 to Interstate 59 corridors. In this region, CAMs, including REFS, HREF and HRRR, indicate some slow moving to stationary propagation of rain and storms. This leads to some outlook of training convection and heavier totals, potentially in excess of 3 to 5 inches in a short period of time. REFS and HREF probs of exceeding 5 inches are in the low chance range (20 to 30 percent) and have trended lower than earlier runs. This would be extremely beneficial but in low-lying/urban areas, could cause localized flash flooding. Based on that, kept the ongoing HWO flash flood threat graphic going with no adjustments. Highs will be seasonably warm, some 4 to 10F above (75F to 85F with warmest along and south of Interstate 20).

As the shortwave digs through into this evening, rain chances will persist and could impact some evening Halloween outdoor activities. With the scattered nature, outdoor plans may still proceed without any disruptions. However, have a plan in place if rain occurs at your location. As a stronger and deeper shortwave ejects east out of the Plains into the Ozarks, the highest rain totals and rain coverage (50 to 80 percent) will move in after midnight north of Interstate 20 into the Highway 82 corridor. This will swing through the day Sunday as ridge builds over the Rio Grande Valley and into the Gulf Coast states. Rain coverage lessens into Sunday afternoon to evening. Highs Sunday will be more seasonable in northeast MS while seasonably warm to the southwest. Lows tonight and Sunday night will seasonably warm, some 12F to 20F above (57F to 65F). Relevant portion of previous forecast discussion is below. /DC/

Next week: Shortwave ridging will keep things dry Monday in advance of a cold front. Subtropical jet will aid in lee cyclogenesis off the Rockies Monday. The corresponding surface low will rapidly deepen, drawing moisture northward with storm development along its cold front. The front should push through our area mainly overnight Tuesday into Wednesday morning and progressively weaken as the low lift northward, but there are some synoptic amplitude/upper low differences between global guidance (which slows down frontal timing). Both on WXnext2 and Stormnet, show low severe probabilities to our west and into far western portions of our area. Stormnet lightning probabilities diminish as the system moves east, suggesting weakening by early Wednesday morning. That said, potential secondary low development could reinvigorate activity in the southeast Wednesday. As far as severe potential goes, chances overall look low. Linear storm mode and high shear low cape type environment suggest a primary wind/tornado risk, which would likely be isolated with greatest chances west of I-55 and the river. We may also have to watch for a heavy rainfall threat with anomalous PWAT concentrated along the boundary. Some guidance is showing bullseyes in the west of 2 or more inches in a short period. More details will come in future forecast updates.

Due to the secondary low development, moisture wrap around lingers, so low (15-20%) rain chances continue into Thursday. Additional rainfall amounts to generally under a tenth of an inch. The jet remains active and persistent moist trajectories may keep isolated rain chances around to end the week. /SAS/DC/

AVIATION

(18Z TAFS) Issued at 1222 PM CDT Sat Oct 31 2026

With clouds across the region, in addition to some patchy sprinkles, VFR flight categories will continue at area TAF sites this afternoon and evening. Later tonight into early Sunday morning, flight categories are forecast to lower to MVFR/IFR statuses areawide as both mid and low level moisture increase further as a disturbance aloft moves across the region. This disturbance will bring about both low clouds and an increasing coverage of mainly light to moderate shower activity across the area, thus resulting in the degradation of flight categories across the area. Winds throughout the majority of this 18Z forecast period, will have an easterly component and sustained between 5-10 knots, with a few higher gusts during the afternoon. /19/

PRELIMINARY POINT TEMPS/POPS

Jackson 63 76 60 79 / 70 60 10 0 Meridian 60 71 56 76 / 80 60 20 10 Vicksburg 61 79 61 81 / 50 50 10 0 Hattiesburg 64 76 59 80 / 70 60 20 20 Natchez 64 80 63 82 / 40 50 0 10 Greenville 61 76 60 79 / 70 70 0 0 Greenwood 59 73 58 77 / 80 80 10 0

JAN WATCHES/WARNINGS/ADVISORIES

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