Weather on Friday May 17 2024 Heavy and locally severe weather moves into Atlanta ...Fair elswhere and nice Northeast US

...Dangerous and life-threatening flash flooding likely today for portionsof eastern Texas and western Louisiana......Potentially significant heavy rainfall threat spreads into portions ofsouthern Mississippi and western Alabama tomorrow......Sweltering heat continues across South Florida and South Texas intothis weekend...The main weather story today remains the dangerous and life-threateningflash flood potential over the Lower Mississippi Valley into the overnighthours as widespread thunderstorms batter areas which are very vulnerableto additional rainfall. Since the upgrade to a High Risk (level 4/4) ofExcessive Rainfall last night, little has changed this afternoon regardingthe placement and severity of the flash flooding threat in eastern Texasand western Louisiana. Radar across east-central Texas this afternoondepicts an expansive thunderstorm complex growing along a warm front, withvery moist and unstable air feeding into it to support continuous stormdevelopment this afternoon. Going into the evening and overnight hours,repeating of these thunderstorms containing very heavy rainfall rateswithin the complex will lead to rainfall amounts of 5-8" today within theHigh Risk area over eastern Texas and western Louisiana before thethunderstorms migrate eastward by tomorrow morning. Remember, High Risksfor Excessive Rainfall are a BIG DEAL: 1/3 flood related fatalities and4/5 flood related damages occur in WPC High Risks, so pay attention to thelatest warning information and NEVER drive or walk into floodwaters.Flooding aside, the same storms are also capable of producing a fewtornadoes, severe wind, and hail, with the Storm Prediction Centermaintaining an Enhanced Risk (level 3/5) of severe weather over much ofthe same area today. By tomorrow morning, the threat of significant flash flooding will spreadeast into southern Mississippi and western Alabama as the aforementionedwarm front stalls out over the Southeast. Once again, a very moist andunstable atmosphere appears primed to support bouts of prolific heavyrainfall, with multiple rounds of storms expected as multiple disturbancesaloft traverse the area. When combined with saturated soils from recentheavy rainfall, a Moderate Risk (level 3/4) is in effect tomorrow withareal rainfall amounts upwards of 2-5" (locally up to 7") possible. Itshould be noted that there is some uncertainty with where the heaviestrain falls owing to how the current storms in Texas behave later today, sostay tuned for any adjustments to the forecast. Once again, severe weatherwill also be an issue south of the warm front across the Gulf States, witha Slight Risk (level 2/5) in effect for few tornadoes, very large hail,and damaging wind.The same warm front driving the thunderstorms will also contribute tosweltering heat in South Florida and Texas. Recent experimental NWSHeatRisk guidance continues to suggest moderate to locally major heatrelated impacts will continue across these areas at least through Saturdaydue to the combination of heat indices eclipsing 100 degrees, with littleovernight relief expected.