Notice to Navigators: NWS/NOAA Severe Weather

Significant Event Outlook - Significant Tornadoes and Flooding
Possible in the South Monday and Tuesday

Key Points

• An area of low pressure over the Four Corners states today will move over the southern Plains Monday then to the mid-Mississippi Valley through Tuesday night.
• A cold front extending south of this storm is expected to trigger strong to severe thunderstorms which may bring significant (EF2+) tornadoes, excessive rainfall, and flooding to parts of the South Monday and Tuesday.

Significant Tornadoes:

• The NWS Storm Prediction Center (SPC) has issued an Enhanced Risk for severe thunderstorms (Level 3 of 5) for eastern Texas Monday; very large hail and significant tornadoes are possible.
  • The threat for strong tornadoes is forecast to increase into the evening and overnight hours, as storms move eastward across Texas.
• SPC has issued a Moderate Risk for a substantial severe thunderstorm event, including potential for significant tornadoes, over the lower Mississippi Valley/central Gulf Coast region on Tuesday.
  • Into the evening and overnight hours, the potential for tornadoes and damaging winds will continue.
• Strong to severe thunderstorms may shift into the Southeast U.S. on Wednesday with damaging winds and a couple of tornadoes from northern Florida into southeast Virginia.

Excessive Rainfall and Flash Flooding

• The NWS Weather Prediction Center (WPC) has issued a Moderate Risk (Level 3 of 4) for excessive rainfall due to training of thunderstorms which lead to flash flooding (training thunderstorms produce tremendous rainfall over relatively small areas leading to flash flooding):
  • Monday over eastern Texas and northwest Louisiana
  • Tuesday from northern Louisiana into central Alabama.

Riverine Flooding

• The National Water Center (NWC) and River Forecast Centers (RFCs) are messaging that scattered minor with isolated moderate river flooding is possible over portions of eastern Texas, the lower Mississippi, lower Ohio, and Tennessee valleys, and into western Alabama starting late Monday into Wednesday.
• Some rivers are already in minor flood stage through the region and may see additional rises or delayed recessions.

NOAA/NWS Activities

• Aviation Weather Center (AWC) National Aviation Meteorologists are briefing FAA advanced planners about expected aviation impacts from thunderstorms in the southern U.S. for Monday and Tuesday.
• Weather Forecast Offices (WFOs) Birmingham, Fort Worth, Houston, Huntsville, Jackson, Lake Charles, Memphis, Mobile, New Orleans, San Antonio, Shreveport, Tallahassee, and the Southern Region Regional Operations Center (SR-ROC) have been sending email briefings to emergency management partners regarding the severe weather and heavy rainfall potential Monday and Tuesday. They are also hosting targeted webinars

Links

• NWS River Forecasts Near or Above Flood Stage
• NWS Weather Prediction Center
• NWS Storm Prediction Center
• NWS Aviation Weather Center
• National Radar

Graphics

SPC Severe Weather Outlook for Monday.

SPC Severe Weather Outlook for Tuesday.

WPC Excessive Rainfall Outlooks for Monday and Tuesday.

National Digital Forecast Database Rainfall through 8am ET Wednesday.

Twitter Post from NWS Jackson, Mississippi.

Information in this report was provided by the SR-ROC, SPC, WPC, NWC, and AWC NAMs.

 

Please note that some of the information contained in this report may be administratively sensitive, please limit forwarding to additional parties.

 

NWSOC Mission: The NWS Operations Center provides timely Impact-Based Decision Support Services to meet the evolving needs of NWS partners and stakeholders and supports agency readiness by proactively collaborating and facilitating the exchange of critical information, setting operational posture, and briefing leadership.

 

NWSOC Vision: A Weather-Ready Nation that makes informed and timely decisions based upon the best environmental and situational awareness information achieved through continuous and effective collaboration.