Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 301 AM EST Mon Nov 20 2023 Valid 12Z Mon Nov 20 2023 - 12Z Wed Nov 22 2023 ...Enhanced Risk of severe weather across the Deep South later today/tonight ahead of a low pressure system... ...Locally heavy rain and possibly strong thunderstorms across the Mid-Mississippi Valley today and then across the interior Mid-Atlantic Tuesday into early Wednesday... ...High-elevation snows and lower elevation rain across the central and southern Rockies/High Plains expected to taper off tonight... ...Santa Ana winds develop over southern California during the next couple of days... A low pressure system currently developing over the mid-section of the country will send a wave of inclement weather through the eastern two-thirds of the country through the next couple of days. The most significant bout of inclement weather appears to be later today into tonight from eastern Texas to the lower Mississippi Valley where outbreak of severe thunderstorms are possible as a dynamic cold front associated with the intensifying low pressure system sweeps across. Some of the thunderstorms could contain high winds and tornadoes, together with heavy downpours and hail. The speed of the system is expected to limit the threat of flash flooding for these areas. By Tuesday, the center of the low pressure system is forecast to reach the lower Great Lakes bringing widespread rain with some embedded thunderstorms from the Midwest to the lower Great Lakes and Ohio Valley, and quickly toward New England Tuesday night. Temperatures will probably be cold enough to support some wet snow early on Tuesday over the upper Midwest, reaching eastward into interior New England by Tuesday night along with some freezing rain possible. Meanwhile, some strong thunderstorms can be expected to track across the Tennessee Valley/interior Southeast early Tuesday, followed by the southern Appalachians and into interior Mid-Atlantic by Tuesday night into early Wednesday as a low pressure wave forms and tracks along a warm front. Colder air will then be ushered across the central and southern Plains behind the low pressure system. Some high-elevation snows and lower elevation rain are expected across the central and southern Rockies/High Plains today but they are expected to taper off tonight behind the intensifying system. A large dome of high pressure building behind departing low pressure system will then settle across much of the western U.S for the next few days. Tight pressure gradient around the High will promote Santa Ana winds especially across southern California. High temperatures today and Tuesday will remain below average from New England south into the Mid-Atlantic following a frontal passage, with 30s and 40s for New England and 50s into the Mid-Atlantic. In the South, conditions will be unseasonably warm ahead of the approaching frontal system, with 70s and even some 80s along the Gulf Coast. The digging trough over the central U.S. will bring cooler and below average temperatures south into the Southern Plains and Texas by Tuesday, with widespread 50s expected. Highs will be more seasonably cool further north across the Northern Plains into the Great Lakes with mainly 40s forecast. Temperatures will moderate in the West after a cooler weekend, with 40s and 50s for the Great Basin/Rockies, 50s and 60s for the Pacific Northwest and northern California, and 70s for Southern California and the Desert Southwest. Kong/Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php