5/12 – Trey Tonnessen’s “Excessive Rainfall” Sunday Night Forecast

Meteorologist Trey Tonnessen

Good Sunday evening!  Severe weather is back in the forecast, even though our risk areas are not as high as several places in the region have seen recently, it is still worth noting that the potential will be here over the next two days. After looking at weather model data, I am decently certain on the modes of severe weather that are most likely. Three Weather Service offices cover our WXXV viewing area, and often times we could get multiple watches in reference to arrival timing, this is not always a bad thing. It gives us Meteorologists here three separate offices of weather analysis to consider and compare to our own severe weather forecasts. With that in mind… This is the most likely scenario for tonight through Tuesday:

South Mississippi will have multiple rounds of heavy rain and severe weather through Tuesday. The greatest threats will come in two rounds – this evening (Sunday) into Monday morning and Monday evening through Tuesday morning. Scattered storms will continue to be possible between the two rounds.

• The threat of heavy rainfall/flash flooding has increased for both tonight and tomorrow night and the area of greatest threat has expanded. 
• A flood watch has been issued for the entire area beginning at 7:00 PM this evening
• The threat of severe weather has increased for tonight and remained about the same for Monday/Monday night

OVERVIEW (Round 1):

WHAT:  MARGINAL to SLIGHT RISK of Heavy Rain that could lead to flash flooding

             MARGINAL to SLIGHT RISK of Severe Weather

WHEN:  Mainly late tonight through Monday morning for heavy rain

              This evening through tonight for severe weather

WHERE: Mainly north of the I-10/12 corridor

• Rainfall of 1 to 3 inches is currently forecast with locally higher amounts possible
• High rainfall rates could overwhelm short-term drainage capacity, leading to ponding of water in low lying and poor drainage areas
• Localized flash flooding is possible

OVERVIEW (Round 2):

WHAT:  MODERATE RISK of Heavy Rain that could lead to flash flooding

             SLIGHT RISK of severe weather

WHEN: Monday afternoon through Tuesday morning, with the main threat during the evening through early morning hours

WHERE: All of Southern Mississippi 

• Rainfall 1 to 3 inches with locally higher amounts possible
• High rainfall rates could overwhelm short-term drainage capacity, leading to ponding of water in low lying and poor drainage areas
• Localized to scattered areas of flash flooding are possible
• As water drains into area rivers, rises are expected. However, with current water levels running near or below normal, there are no immediate river flooding concerns.

• Damaging wind gusts and large hail
• Tornadoes cannot be ruled out
• Tree damage, power outages, and even isolated structural damage will be possible from any storms that become severe.

Thanks for trusting WXXV Your Weather Authority with your severe weather forecasts! Stay weather aware.

-Meteorologist Trey Tonnessen