Steady rain ending, isolated storms possible later
Steady rain is ending from west to east but still may cause some lingering issues during the morning commute. Isolated showers and storms are then possible this afternoon before a cold front clears the region.
Today and Tonight: Showers and thunderstorms are expected—especially through dawn and especially south of I-10. Some of the thunderstorms could produce heavy rain. A lull is expected to begin by late morning. By afternoon, some sunshine will try to return and highs will make it into the upper 70s. There may be just enough heat energy to fuel the development of a broken band of showers and thunderstorms as a cold front crosses the area later in the afternoon. While limited, this will maintain the “slight risk” for severe weather later today. Not all will receive a second round of rain later; the best chances will be north of I-12 where more heating occurs. Overnight, skies will clear with lows falling back into the upper 50s.
The National Weather Service (NWS) Storm Prediction Center (SPC) has issued a “slight risk” for severe weather on Thursday. This means scattered severe storms are possible within the forecast area. An isolated intense thunderstorm is possible. On a scale of 1 (lowest) to 5 (highest) severe weather threat, this event is a 2. Another way of describing the threat is that there is a 15 percent chance of experiencing severe weather within 25 miles of a given point in the risk area.
1) Heavy Rain – storms could produce 1+” of rain over a short time
2) Other – gusty wind and hail are possible (only with afternoon storms)
Precipitation: The NWS Weather Prediction Center (WPC) is forecasting 1-2” of rain for the 13 Parish, 3 County Forecast Area through Thursday. Most locations should receive the lower amounts, but particularly heavy thunderstorms will tip gauges toward the higher amounts in a few locations.
Estimated Timeline: The steady and heavy rain will begin to wrap up in the Baton Rouge area shortly after sunrise and then from north to south end in coastal parishes by about mid-morning. A second, quick moving band of showers and storms may flare up and cross the area with a cold front later this afternoon.
Impacts: Persistent rain is expected to slow the morning commute—especially south and east of Baton Rouge. Many typical trouble spots with poor drainage may have standing water. Isolated strong storms could cause wind or hail damage this afternoon. The chance will likely be limited to areas north of I-12.
Actions: Prepare for delays and leave yourself extra time to drive carefully early on Thursday morning. Don’t drive your vehicle into standing water and risk stalling. If there is a weather warning active during your scheduled commute, consider waiting until that storm or pocket of heavy rain passes. Tie down any loose objects and move valuables under cover. Have access to watches and warnings such as with a NOAA Weather Radio or from the WBRZ Weather Team on Facebook and Twitter. Additionally, the *free* WBRZ WX App. sends push notifications to Apple and Android devices if a watch or warning is issued for your location. Remember, a watch means “conditions are favorable, and a particular threat could develop” and a warning means that “threat is happening and you should take action immediately.” For much more detailed severe weather safety, CLICK HERE.
Up Next: With a cold front east of the area, humidity may go down a notch on Friday and Saturday. This will be best noticed with morning temperatures in the upper 50s. Highs will remain above average with afternoon readings near 80 degrees. Another short stretch of sunny days is on tap before yet another storm system brings the threat of heavy rain and strong storms Sunday into Monday.
THE SCIENCE: A wide swath of showers and thunderstorms is slowly progressing east across the forecast area behind a pre-frontal trough. Satellite shows that the upper level trough centered in the Midwest has stalled as it occludes. This is why eastward progression slowed overnight. It appears that the trough is starting to move east again which should bring the bulk of rain and storm action east through the morning as intensity continues to decline. The severe severe threat will be at a minimum through the morning for those reasons but locally heavy rainfall may continue. The band of rain will exit the local area between sunrise and noon. Then will come the more difficult part of the forecast. Some sunshine and subsequent insolation is expected once the rain ends. This may destabilize the atmosphere just enough to fuel a broken band of showers and thunderstorms ahead of a cold front that will cross the area this afternoon. The SPC continues a “slight risk” all the way to the Gulf Coast but it would seem that the better chances for afternoon storms will be north of the interstates. This is where storms may be able to produce gusty wind and hail—but there is low confidence in any severe weather materializing this afternoon. Friday and Saturday will be dry and warm as trough moves east and an upper ridge builds in over the area. Temperatures will remain above average. An upper level low diving out of the Northwest U.S. today will be moving into the Southwest U.S. by Saturday. Forecast models show the low rotating back across Northern Louisiana by Monday. Timing differences between the ECMWF and GFS have decreased as the ECMWF has sped up slightly. The close proximity of the upper low will set the stage for strong kinematic forcing from the surface to the upper levels. Model soundings show a very saturated column, which combined with strong instability, will likely lead to heavy rainfall potential. A return to warm temps and no rainfall will return Monday and persist through middle of the week.