Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 125 PM EDT Tue Jul 20 2021 Valid 00Z Wed Jul 21 2021 - 00Z Fri Jul 23 2021 ...Midsummer heat found throughout the northern and central Plains... ...Elevated fire weather concerns continue across the northern Rockies and northern Great Basin... ...Isolated chances for severe thunderstorms and flash flooding possible for the Lower Great Lakes and Northeast today... A persistent, but gradually weakening upper-level ridge over the central U.S. will provide a continuing stretch of above average temperatures across the northern and central Plains through at least midweek. Widespread high temperatures into the upper 90s and low triple digits are forecast here, which is slightly lower than what was felt yesterday. These warm temperatures and lack of rain will likely worsen the ongoing severe to exceptional drought found throughout the region. Excessive Heat Warnings remain in effect across eastern Montana. Farther west, the combination of extreme drought, gusty winds, and thunderstorms will produce fire weather concerns for the northern Great Basin and northern Rockies through Thursday. Thunderstorms ahead of an advancing cold front entering the Pacific Northwest today are likely to produce little rainfall, but lightning could reach the dehydrated terrain and spark new wildfires, with drying expected behind a modified Pacific cold front moving slowly through the region. The areas with the greatest chances of seeing summer storms include the Northeast, Lower Great Lakes, Southeast, and Southwest. A cold front crossing the Lower Great Lakes with thunderstorms in tow are forecast to shift into New England and coastal sections of the Northeast tonight and Wednesday; some storms could be severe tonight. For the Southeast and Gulf Coast States, a lingering frontal boundary bisecting the region will be the focus for additional rounds of slow-moving thunderstorms today before lifting slowly northward Wednesday and Thursday. The main concern with these storms will be associated with heavy rainfall and scattered flash flooding tonight, with the threat fading in coverage and intensity on Wednesday and Thursday. The Southwest Monsoon is expected to continue with scattered chances of thunderstorms through much of this week. As a result, isolated instances of flash flooding will remain a possibility between the Southwest and central Great Basin, especially on Thursday. Roth/Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php