textproduct: Jackson

KEY MESSAGES

- Significant flash flooding threat continues with conditions worsening late Wednesday night 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.

DISCUSSION

Issued at 116 AM CDT Wed Jun 17 2026

Today...

Reinforced shortwave ridging will tend to suppress convection/rainfall today, which is certainly good news for those who received the greatest amounts yesterday. During this break however, there may still be ongoing hydrologic response to yesterday's rainfall, so creeks and smaller rivers may remain elevated. We still anticipate potential for significant flash flooding associated with a tropical low expected to pass over the area tomorrow. Note, this will be additional rainfall to what has already fallen this week so far. Minor adjustments were made this forecast update to account for the southward trend. As such, "significant" flash flood threat was trimmed from the northwest and some of the northeast, and expanded into the east and southeast. Totals within the "significant" were also adjusted slightly upward to reflect latest guidance.

Through mid next week...

The tropical Gulf low will be the focus for the next round of heavy rainfall tomorrow for our area. This feature will carry with it a very moist airmass possibly in excess of 2.5 inch PWAT. Given antecedent conditions, this additional round will exacerbate flash flood threat, especially for areas that received great amounts yesterday. While TC development probabilities continue to be 60%, the primary threat of flash flooding remains unchanged, therefore hazard messaging remains consistent.

There will also be a low end risk for severe associated with the tropical low. Despite moist adiabatic lapse rates, low level shear may be enhanced by the low. Along with significant deep moisture, embedded low topped supercells cannot be ruled out, though the risk remains low. The primary severe concerns would likely be wind and perhaps a weak tornado within the tropical regime.

There is renewed concern for flash flood threat to continue into Friday as a boundary in the wake of the tropical low stalls somewhere in the vicinity of I-20. The placement of this feature is uncertain at this time, but more guidance seems to be picking up on it. We will continue to watch closely and provide future updates.

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 next week may mean that relief may be on the way. /SAS/

AVIATION

(06Z TAFS) Issued at 116 AM CDT Wed Jun 17 2026

Ceiling/vsby forecasts are complex and variable through early this morning with areas of fog having developed mainly over northeast portions of the forecast area. Near term guidance suggest the worst of vsby restrictions will be temporary and should improve quickly around daybreak as gradient southerly winds begin to pick up, but widespread LIFR category ceilings will be common in any case until greater mixing develops after sunrise and helps to quickly improve ceilings to MVFR/VFR by late morning. Otherwise, we'll be in a relative lull in terms of rain coverage ahead of the approaching tropical system. /EC/

PRELIMINARY POINT TEMPS/POPS

Jackson 88 74 85 74 / 40 80 90 70 Meridian 88 74 83 73 / 50 80 100 80 Vicksburg 88 74 87 75 / 30 70 90 60 Hattiesburg 86 75 83 75 / 50 80 100 70 Natchez 88 75 87 76 / 50 90 90 60 Greenville 90 75 89 74 / 10 40 50 60 Greenwood 91 75 88 74 / 20 60 70 60

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.