Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 445 PM EDT Sun Aug 29 2021 Valid 00Z Mon Aug 30 2021 - 00Z Wed Sep 01 2021 ...Category-4 Hurricane Ida ravaging southeastern Louisiana before weakening and turning north and northeast across the lower Mississippi Valley and into the Tennessee Valleys... ...Heavy rain and initially hurricane-force wind gusts expected to spread across Mississippi toward the Tennessee Valleys during the next couple of days... ...Slight risk of severe thunderstorms over the Great Lakes into tonight, then across the northern Plains on Monday... ...Excessive heat over parts of southern California and the Desert Southwest into Monday; then watching moisture from Tropical Cyclone Nora begins to arrive on Tuesday... Hurricane Ida rapidly intensified into category-4 intensity early this morning before making landfall near Port Fourchon, Louisiana around midday local time with 150-mph sustained winds. Weakening ensures as Ida is forecast to move further inland across southeastern Louisiana into this evening. Ida possesses a relatively large circulation with concentric eyewalls around its core and multiple intense rainbands around its outer circulation. Widespread hurricane-force wind gusts appear likely to spread further inland tonight together with extended periods of heavy rain. The high wind gusts could spread further north across Mississippi on Monday as Ida is forecast to turn north-northeastward. Additionally, the Storm Prediction Center has issued a Slight Risk mainly for isolated tornadoes for areas east of the lower Mississippi Valley into tonight. As Ida tracks further to the north and northeast during the next couple of days, a cold front is forecast to drop south across the Ohio Valley. The increasing interaction between the two systems will likely result in multiple inches of rain, leading to an increasing threat of flash flooding into Tennessee Valleys through Tuesday--especially where antecedent heavy rain has recently occurred. In addition, isolated tornadoes remain possible through Tuesday ahead of Ida. Ahead of the aforementioned cold front, showers and thunderstorms could become severe over parts of the upper Great Lakes into tonight, where strong wind gusts, hail, and a few tornadoes are possible. Scattered thunderstorms can be expected across the Northeast on Monday ahead of this same front but cool air and clearing skies are expected to arrive on Tuesday following frontal passage. Meanwhile, showers and thunderstorms north of the trailing portion of this front could become severe later on Monday across parts of the northern Plains towards the mid-Mississippi Valley where excessive rainfall will be possible as well. Meanwhile, much of the western U.S. will remain dry through Tuesday. The exception will be across the higher terrains of Arizona and New Mexico where some late-day monsoonal showers and thunderstorms can be expected. The Desert Southwest will remain quite hot into Monday where Heat Advisories and Excessive Heat Warnings remain in effect. By Tuesday, moisture from tropical cyclone Nora near the west coast of Mexico could begin to stream into the Desert Southwest, bringing a increasing threat of heavy rain into the region. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php