Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 334 AM EDT Thu Jul 22 2021 Valid 12Z Thu Jul 22 2021 - 12Z Sat Jul 24 2021 ...Monsoon intensity and the threat of flash flooding to ramp up across the Southwest... ...Midsummer heat persists across the Northern/Central Plains and spreads into the Midwest, with the threat of severe thunderstorms on Friday... ...Elevated to critical fire weather concerns remain throughout the Northern Rockies and Great Basin... The Southwest Monsoon has been very active as of late, but a more notable increase in intensity is expected over the next few days. An upper-level ridge centered over the Four Corners and an upper-level low retrograding westward out of Texas will help funnel anomalous atmospheric moisture into the region. Widespread rainfall amounts could reach over an inch both today and Friday across parts of Arizona, New Mexico, and southwest Colorado, with Friday forecast to be the more active day. While this rain is a welcome sight across the drought-stricken areas of the Southwest, intense downpours could lead to dangerous flash flooding. Recent burn scars will be even more susceptible to rapid runoff and debris flow. A Slight Risk (level 2/4) of Excessive Rainfall has been issued across much of central and eastern Arizona, western New Mexico, and southwest Colorado. Flash Flood Watches have also been issued here to highlight the potential hazard. Hot summer days are expected to continue into the beginning of the weekend throughout the Northern and Central Plains, as well as parts of the Midwest. High temperatures are forecast to climb into the upper 90s and low triple digits, which equates to around 10 to 15 degrees above average for this time of year. Excessive Heat Warnings remain in effect for eastern Montana. As a cold front eventually reaches the Northern Plains on Friday, thunderstorms are expected to develop and possibly turn severe between North Dakota and northern Minnesota. Damaging wind gusts and large hail are expected to be the main concern. Farther west, gusty winds and dry lightning combined with the established dry terrain will lead to yet another day of fire weather concerns between the Great Basin and northern Rockies. Elevated to critical fire weather extends from the northern Sierra Nevada to northwest Montana, where wildfires are expected to be most likely to spread uncontrollably. Many residents across the central and eastern U.S. have likely noticed very hazy skies due to wildfire smoke transported from western sections North America. Smoke is forecast to be thickest across the Carolinas, Ohio/Tennessee Valleys, Great Lakes, and Upper Midwest today. As a result, Air Quality Alerts have been issued for certain locations between Minnesota to North Carolina. Elsewhere, scattered showers and thunderstorms associated with a gradually lifting warm front are likely over the next few days throughout the Upper Great Lakes. Portions of the Southeast and the Florida Panhandle are also in store for thunderstorm chances as a stationary boundary and area of low pressure linger near the region. A few isolated instances of flash flooding are possible today across southeast Georgia and the South Carolina Lowcountry. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php