Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 PM EDT Tue Jul 13 2021 Valid 00Z Wed Jul 14 2021 - 00Z Fri Jul 16 2021 ...Heavy rain and severe thunderstorms possible for portions of the Northeast and Lower Great Lakes this evening... ...Severe weather and scattered flash flooding to impact parts of the Northern High Plains and Central Plains tonight, shifting into the Midwest on Wednesday... ...Heat wave continues for much of the western U.S. through Wednesday, while monsoonal moisture produces flash flood concerns throughout the Southwest and southern Utah... In typical mid-July fashion, the main weather stories across the Lower 48 over the next few days include severe thunderstorms, heavy rain, and excessive heat. Through tonight, areas of severe weather and instances of flash flooding are possible for parts of the Northeast, Lower Great Lakes, and into the Ohio Valley. A warm and humid airmass south of a lifting warm front will fuel thunderstorms capable of producing isolated tornadoes, damaging wind gusts, large hail, and intense rainfall rates. The greatest chance of seeing impacts associated with these thunderstorms this evening will be found across Upstate New York and much of Pennsylvania. Meanwhile, an upper-level shortwave is expected to spark severe thunderstorms across the Northern High Plains this evening, which could impact parts of South Dakota and northern Nebraska overnight. The Storm Prediction Center has issued an Enhanced Risk (level 3/5) of severe weather from northeast Wyoming to southwest South Dakota. Severe wind gusts and large hail are the main concerns across this region. By Wednesday, the threat of severe thunderstorms shift into the Midwest and Upper Great Lakes ahead of an advancing cold front and strengthening area of low pressure. SPC has issued an Enhanced Risk for severe weather on Wednesday that includes the northern half of Iowa, southern Minnesota, and central/southern Wisconsin. Flash flooding will also remain possible as thunderstorms interact with an abundance of atmospheric moisture, with over 3 inches of rain possible in certain locations that experience multiple rounds of storms. The aforementioned cold front and associated thunderstorms are forecast to push into Michigan and the Middle Mississippi Valley on Thursday. For the West, monsoonal moisture is expected to continue producing scattered showers and thunderstorms through Thursday over parts of Arizona, Utah, and New Mexico. Rainfall amounts in excess of 1 inch can produce flash flooding in particularly sensitive areas. Flash Flood Watches have been issued. Heat will also remain a concern throughout central California and the Intermountain West before slightly cooler temperatures arrive on Thursday. Highs into the upper-90s and low triple digits will be felt throughout the region, including as far north as interior Washington and northern Idaho on Wednesday. Above average temperatures are forecast to shift into the Northern Rockies and Northern High Plains by Thursday. With ongoing heat for much of the West and widespread extreme drought conditions in place, wildfires may be easier ignited and more capable of spreading uncontrollably throughout this part of the country. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php