Weather Advisory

From:  Harrison County Civil Defense   4/30/17   GCN

 

Here is an update concerning the severe weather and heavy rain threat for today. 

 

Storms are already ongoing across the western portions of the forecast area this morning. Expect this line of strong to severe thunderstorms to continue to march east through the day. We still are on track with the timing. Areas around Baton Rouge and McComb will see the worst weather from now through 11 AM, and then New Orleans, and the MS Gulf Coast should see the worst weather starting around the noon time hour and last through the afternoon. All modes of severe weather are possible...tornadoes, strong damaging wind gusts, and large hail.

 

Heavy rainfall will also be an issue today. Expect very high rainfall rates with these storms as they train over the same areas. Rainfall rates of 1.5 to 2.5 inches per hour will be possible with these storms. Expect rainfall totals of 2 to 4 inches with locally higher amounts to occur with these thunderstorms. Street flooding in low lying and poor drainage areas will be the biggest issue and some rivers could rise into minor flood stage

 

A Wind Advisory will be in effect for all of southeast Louisiana and southern Mississippi through this evening for sustained winds around 25 mph with gusts to 35 to 40 mph. 

 

A Coastal Flood Advisory is in effect for all coastlines through this evening. Persistent southerly winds are likely to produce tides 2 feet above normal during high tide cycle. High tide times will be during the afternoon hours today. A change in wind direction will ease the coastal flood threat on Monday

 

 

Overview:

 

WHAT SLIGHT RISK to ENHANCED RISK of Severe Weather

 

WHEN:  Sunday morning through Sunday evening. 

 

WHERE:  Enhanced Risk north of Lake Pontchartrain and across southwest Mississippi. Slight Risk across the remainder of southeast Louisiana and coastal Mississippi.

 

CONFIDENCE:  High confidence in strong to severe storms occurring, High confidence in heavy rain producing some flash flooding. 

 

Possible/Expected Impacts:

The main threats associated with any severe storms will be:

·  Wind gusts up to 65 mph which could down trees and powerlines and/or cause structural damage

·  Large hail

·  Isolated tornadoes

In addition to the severe weather threat, rainfall of 2 to 4 inches will be possible.  Locally heavy rainfall could lead to ponding of water in low lying areas and areas of poor drainage.

 

The graphic below highlights the severe weather threat area.

 


 

 

Additional Information and Resources:

NWS New Orleans Website: www.weather.gov/neworleans

NWS New Orleans DSS Website: http://www.srh.noaa.gov/lix/?n=embrief

River Gauges and Forecasts: http://water.weather.gov/ahps2/index.php?wfo=lix

NWS New Orleans Facebook: www.facebook.com/NWSNewOrleans

NWS New Orleans Twitter: https://twitter.com/NWSNewOrleans

Online Severe Weather Reporting: http://www.srh.noaa.gov/StormReport/SubmitReport.php?site=LIX

 

Request for information: (Delete this entire section if threat is not in the current period)

Please relay any reports of severe weather or flash flooding to our office ASAP.  You can send reports via NWSChat or by phone.  If emailing 
pictures, please send them to <sr-lix.forecasters@noaa.gov>.