textproduct: Jackson

KEY MESSAGES

- Significant flash flooding threat continues with conditions worsening late tonight into Thursday.

- Rainfall will continue on Friday. Flooding impacts may linger. Rainfall does not end quickly, but rather gradually tapers over the course of several days.

- Isolated severe storms are possible over the area Thursday and Friday.

DISCUSSION

Issued at 126 PM CDT Wed Jun 17 2026

Through this evening: Local radars have broken out in a rash of convection across the whole CWA. Most of this activity will be in the form of showers but a rumble of thunder or two is possible. TS Arthur that developed off the central Texas coast this morning is forecast to move northeast along the Texas coast this afternoon and then inland over southwestern Louisiana by tonight. TS Arthur will then weaken as it continues moving inland and to the northeast, reaching our northeast Louisiana Parishes by Thursday morning. The main threats to our CWA from TS Arthur remain unchanged and will remain the flooding rain threat especially across our southern zones. /22/

Later tonight through the middle of next week...

The remnants of Tropical Storm Arthur will be the focus for the next round of heavy rainfall late tonight into tomorrow across the area. This feature will carry with it a very moist airmass (2.3-2.6 inch PWAT). Given antecedent conditions, this additional round will exacerbate the flash flood threat, especially for areas that received recent heavy rainfall.

Generally along and east of the eventual track of any remnant circulation, adequate low level shear will allow for some low-end risk of a brief, weak, tornado or two. The primary threat by large margin continues to be the risk for flash flooding, likely significant, with some risk for impacts to structures and numerous flooded roadways. The areas of highest risk appear to be approximately the southeastern half of Mississippi though flash flood risks will be possible across the area. Additional rainfall totals in this "Significant" risk area will likely reach 4 to 8 inches though isolated amounts approaching a foot could be possible. This represents an event with an unusually high ceiling for flooding impacts which could include water rescues being necessary with impassable roadways, particularly in urban or poor drainage environments where runoff is maximized. Given the current/existing wet conditions, flash flooding could begin more quickly than otherwise expected with the onset of heavier rains. A flood watch remains in effect for areas generally along and south of the I-20 corridor. /lP/

There remains some concern for a flash flood threat to continue into Friday as a boundary in the wake area of the remnant low stalls somewhere in the vicinity of I-20. With this activity, a low end (Marginal) risk for severe weather will be possible for much of the area. Overall confidence remains low regarding the exact degree of flash flood risk that will continue into Friday as part of the net impact will be affected by exact amounts and locations of the higher totals through tomorrow. A risk outlook was not issued this forecast cycle with the thinking that the flash flood threat will begin to become more riverine/areal with time. Flood warnings are already in place for some area rivers with substantial rises expected. /86/

The boundary begins to make headway into the area by the weekend and likely washes out this weekend. Airmass modification is likely slim, but PWAT, while still supportive of additional rainfall, will be more seasonal (1.5-1.7). This should provide some "break" from the onslaught of moisture, with coverage overall more scattered this weekend. Additional rainfall amounts this weekend generally look to be in the 1 to 2 inch range. Southwesterly flow will continue to reinforce rain chances through the remainder of the period, but increased westerly/northwesterly flow by the middle of next week may mean that relief may be on the way.

AVIATION

(00Z TAFS) Issued at 736 PM CDT Wed Jun 17 2026

VFR conditions and isolated SHRA and TSRA to start the TAF period. Lowering ceilings and increasing chances for RA after 06Z as the remnants of Tropical Storm Arthur move across the forecast area. Areas of rain will be accompanied by reduced visibility and potentially gusty winds. /NF/

PRELIMINARY POINT TEMPS/POPS

Jackson 74 85 74 88 / 80 90 70 90 Meridian 73 82 73 87 / 90 100 70 90 Vicksburg 74 87 75 89 / 70 90 70 80 Hattiesburg 74 84 76 90 / 90 100 60 80 Natchez 74 88 77 91 / 90 90 50 80 Greenville 75 89 74 87 / 20 50 70 80 Greenwood 75 88 74 87 / 40 70 80 80

JAN WATCHES/WARNINGS/ADVISORIES

MS...Flood Watch through Thursday evening for MSZ040>066-072>074.

LA...Flood Watch through Thursday evening for LAZ009-015-016-023>026.

AR...None.