Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Fri Oct 11 2024 Valid 00Z Sat Oct 12 2024 - 00Z Mon Oct 14 2024 ...Record-breaking heat forecast this weekend from parts of the Southwest eastward into the central and south-central U.S... ...Developing storm system to bring unsettled weather to the Ohio Valley, Great Lakes, and Northeast Saturday into Sunday... ...Locally heavy rain possible over southeast Florida through Sunday... An expansive ridge of high pressure stretching from the Southwest to the central and southern Plains will result in continued record-breaking heat across portions of the Desert Southwest through this weekend. High temperatures are forecast to reach into the upper 90s and triple digits, which is well above normal for this time of year. Meanwhile, anomalous late season heat will also expand farther east into the central and south-central U.S. on Saturday with highs ranging from the upper 80s to upper 90s. Numerous daily record high temperatures are possible. By Sunday, a cold front will squash the most searing heat southward, bringing some quick relief to the Central U.S. South of the front, yet another day of record heat is likely from Arizona eastward through central Texas into the Lower Mississippi Valley where highs will once again soar well into the 90s to near 100. Elsewhere, unseasonable warmth presses eastward into the Ohio Valley, Mid-Atlantic, and Southeast Saturday into Sunday, with the only cooler than normal spots largely confined to the northern Plains, Great Lakes, and Northeast. The aforementioned cold front is forecast to march eastward across the Great Lakes and Northeast tonight into Saturday before stalling over the Ohio Valley and Mid-Atlantic on Sunday. An area of low pressure is expected to develop along the front over Indiana and Ohio, strengthening as it moves eastward into Pennsylvania by Sunday night. This storm system will bring scattered to widespread showers and thunderstorms to the larger region on Sunday, which may dampen outdoor activities at times. A few isolated strong to severe thunderstorms are possible too, especially along the front from eastern Kentucky to West Virginia. In fact, the Storm Prediction Center has issued a Marginal Risk (level 1 of 5) to highlight this risk on Sunday. Following in the wake of Hurricane Milton, strong northeasterly flow aided by high pressure over the southern Appalachians and northeast of the Bahamas will keep the threat of coastal hazards and locally heavy rain in the forecast along the Atlantic Coast of Florida. In particular, showers and thunderstorms along the southeast Florida coastline may remain somewhat stationary due to weak flow aloft, while also containing intense rainfall rates. As a result, a Marginal Risk (level 1/4) of Excessive Rainfall remains in place for this area on Saturday and Sunday in order to bring continued awareness to the threat of localized flash flooding. Miller/Snell Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php