Good morning coastal folks! Expect highs in the upper 80s today and very moist dew points (around 75F!) which will push the heat index into the upper 90s. Skies will be mostly clear in the morning becoming increasingly cloudy in the afternoon as numerous showers and thunderstorms develop. Storms should begin to develop around 1pm closer to the coasts and push inland throughout the rest of this afternoon and early evening clearing up around 9pm tonight.
A stagnant pattern will be in place over Coastal LA/MS/AL today as areas of high pressure are situated to both the west and east keeping 500mb winds over the region very weak. This pattern is expected to continue with little variation over the next 7 days, with the ridge of high pressure in the west pushing northeastward into the central plains and re-developing over the Rockies by Sunday.
South/southwest winds at the 850mb level are providing lots of Gulf moisture beneath the stagnant 500mb winds, which will allow for pop-up thunderstorms almost daily in the forecast region. The 850mb level in the atmosphere is about one mile above the ground and the 500mb is roughly three and a half miles above the ground. As the Sun heats the surface this afternoon, rising air called ‘thermals’ will push into the moist 850mb layer creating numerous cumulus clouds and initiating thunderstorm development, especially along any sea breeze front that may develop along the coast. The weak 500mb winds mean that when the storms push higher into the atmosphere there won’t be much wind shear to help sustain or move the storms, so they will be pulsing and slow moving.
Overall, as the 500mb winds remain stagnant and low-level moisture remains abundant, wetter weather will persist across Coastal LA/MS/AL the next several days in the form of afternoon/evening showers and thunderstorms. Make sure to take shelter if caught in a thunderstorm as lightning can reach temperatures five times hotter than the surface of the sun (50,000F!). When thunder roars, go indoors!
Day to Day Forecast
Today
Partly cloudy with an 80-percent chance for showers and thunderstorms in the afternoon/evening. Highs in the upper 80s. Heat Index values around 98F.
Tonight
Partly cloudy with a 30-percent chance for showers and thunderstorms. Lows in the lower 70s.
Thursday
Partly cloudy with a 70-percent chance for showers and thunderstorms in the afternoon/evening. Highs in the upper 80s. Heat Index values around 97F.
Thursday Night
Partly cloudy with a 20-percent chance for showers and thunderstorms. Lows in the lower 70s.
Friday
Mostly sunny with a 60-percent chance for showers and thunderstorms in the afternoon/evening. Highs in the upper 80s. Heat Index values around 98F.
Friday Night
Mostly clear. Lows in the lower 70s.
Saturday
Mostly sunny with a 60-percent chance for showers and thunderstorms in the afternoon/evening. Highs in the lower 90s.
Saturday Night
Partly cloudy. Lows in the lower 70s.
Sunday
Partly cloudy with a 60-percent chance for showers and thunderstorms in the afternoon/evening. Highs in the lower 90s.
Sunday Night
Partly cloudy with a 20-percent chance for showers and thunderstorms. Lows in the lower 70s.
Monday
Mostly sunny with a 70-percent chance for showers and thunderstorms in the afternoon/evening. Highs in the upper 80s.
Monday Night
Partly cloudy. Lows in the lower 70s.
Tuesday
Mostly sunny with a 60-percent chance for showers and thunderstorms in the afternoon/evening. Highs in the upper 80s.
Tuesday Night
Partly cloudy. Lows in the lower 70s.
