Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 PM EDT Thu Apr 22 2021 Valid 00Z Fri Apr 23 2021 - 00Z Sun Apr 25 2021 ...Another night of well below-normal temperatures is expected across the eastern U.S., with freeze warnings and frost advisories in place across much of the Ohio Valley and Mid Atlantic... ...A complex low pressure system will bring severe thunderstorms and heavy rains to parts of the southern Plains and central Gulf Coast states on Friday and the Southeast on Saturday... ...Critical fire weather conditions are expected to continue from the Southwest into the southern High Plains on Friday... The low pressure system responsible for bringing late April snows to portions of the Ohio Valley and the Northeast will remain centered over southeastern Canada, supporting additional windy conditions and snow showers across the Northeast into Friday morning. Another night of unseasonably cold temperatures is expected across much of the eastern U.S., with Freeze Warnings and Frost Advisories in effect across a large portion of the Ohio Valley and Mid-Atlantic States. As high pressure over the region begins to move offshore and winds turn to the south, temperatures are expected to begin to climb closer to more seasonable norms during the day on Friday. Isolated to scattered showers and thunderstorms are forecast to develop from parts of the southern Plains into the lower Mississippi Valley and the central Gulf Coast states on Friday into Friday night. These storms may become strong to severe, with large hail, damaging winds, and isolated tornadoes possible. Heavy rainfall and possible flooding is also a concern, especially across northern and central Louisiana to central Alabama. On Saturday, showers and storms are expected to move east from the Mississippi Valley into the Ohio and Tennessee valleys, and then the eastern U.S. Isolated to scattered severe thunderstorms are expected across the Southeast on Saturday, with large hail, damaging winds, and a few tornadoes expected. Heavy rainfall will also remain a threat, especially from Alabama and the Florida Panhandle eastward across Georgia into South Carolina. In stark contrast, the Southwest, southern Rockies and High Plains will remain dry. Gusty winds and low relative humidities have prompted Red Flag Warnings on Thursday from southeastern Arizona to the southern High Plains, including much of New Mexico. Continued dry and windy conditions are expected to promote additional critical fire weather conditions from northern Arizona to the southern High Plains on Friday. Lastly, a system moving into the northwestern U.S. is expected to spread a combination of low elevation rains and mountain snows from the Pacific Northwest and Northern California to the northern Rockies and High Plains on Saturday. Pereira Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php