085 FXUS01 KWBC 291938 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 337 PM EDT Tue Sep 29 2026 Valid 00Z Wed Sep 30 2026 - 00Z Fri Oct 02 2026 ...Considerable flash flooding remains possible tonight from southeast Arizona and New Mexico into West Texas as the remnants of Polo merge with a strong upper-level low... ...Heavy rain and flash flooding shift to the southern Rockies and Southern Plains on Wednesday and Thursday, with a broad area of flood concerns extending to the Great Lakes... ..Warm, dry weather builds across the East behind the departing Nor'easter, with highs approaching 90 from the Mid-Atlantic to the Ohio Valley by Thursday... An upper-level low over the Desert Southwest is forecast to move into New Mexico by Wednesday morning, drawing tropical moisture from the remnants of Hurricane Polo northeastward. Slow-moving thunderstorms will continue this evening across southeast Arizona and western New Mexico, with a line of heavy storms expected overnight from southern and eastern New Mexico into West Texas, including the Pecos River valley. Saturated soils, burn scars, canyons, and low-water crossings are especially vulnerable, where locally significant flash flood concerns exist. WPC has a Moderate Risk (level 3 of 4) of excessive rainfall from the Southwest into the central High Plains, including a targeted area along the Arizona and Utah border. Storms near the remnant circulation could also produce damaging winds and a brief tornado over southeast New Mexico and West Texas. On Wednesday, a dry slot should move across eastern New Mexico and the Panhandles, finally ending the heavy rain over those hard-hit areas. Meanwhile, a strengthening low over the High Plains will pull deep Gulf moisture northward. Moderate Risks are in place for upslope rain along the southern Front range and for a slow-moving line of storms from central Oklahoma into Texas. A Moderate Risk also extends across southeastern Nebraska into western Iowa. SPC has a Slight Risk (level 2 of 5) risk of severe thunderstorms over the Southern Plains, with damaging winds, hail, and a few tornadoes possible. By Thursday, the trough should weaken and stall over the Plains as a cold front settles south. The Moderate Risk then shifts to southeast Oklahoma, the Texas Hill Country, and South Texas, with a Slight Risk from Texas to the Great Lakes. Cooler, drier air will follow the front, and frost is possible across the northern Plains and Upper Midwest late in the week. In the East, the nor'easter will move away from New England, ending the rain. Minor coastal flooding remains possible at high tide along parts of the Mid-Atlantic coast. High pressure will bring a warming trend, with highs 10 to 15 degrees above average. Heat indices near 110 are possible over South Texas on Wednesday before clouds and rain arrive. In the West, a ridge will build, bringing dry weather to the Northwest and above average temperatures to California and the Great Basin. Offshore winds will keep fire weather concerns elevated over parts of California. Eovino Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$