Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 403 PM EDT Thu Mar 14 2024 Valid 00Z Fri Mar 15 2024 - 00Z Sun Mar 17 2024 ...Heavy snow continues into tonight for the Central Rockies and adjacent foothills/High Plains before gradually tapering off through Friday morning... ...A long-duration event of mountain snow and lower-elevation rain expected over the Four Corners region into the weekend... ...Severe thunderstorms and excessive rainfall expected to push southeastward from the Southern Plains/Mississippi Valley Thursday evening further into Texas and the Southeast region on Friday, continuing in Texas Saturday... ...Mild weather continues from the central to the eastern U.S. going into the weekend... An amplifying upper-level trough/closed low continues to dig southward into the western U.S. with a cold airmass settling in across the region. Moisture flowing in ahead of the trough continues to lead to very heavy snow over portions of the Central Rockies into the adjacent High Plains, particularly along the Front Range. Snow rates upwards of 2"/hr will bring several more inches of snow through tonight with storm total snowfall of 1-2 feet, locally as much as 2-4 feet. Gusty winds leading to blowing snow will make travel very dangerous to impossible, with many of the local interstates already closed. The snow should begin to gradually taper off Thursday night and into Friday morning. Snowfall will then shift a bit to the southwest over the Four Corners region as the upper-low settles in overhead for the next couple of days. Waves of heavy snow will bring 12"+ of snowfall to the higher elevations of the regional mountain ranges into this weekend. Lower elevations of the Four Corners will see a mix of rain and snow, though any accumulations should remain limited, with rain also spreading to the Desert Southwest. Some thunderstorms will also be possible. Precipitation chances should continue at least through Saturday evening. To the east, widespread showers and thunderstorms will continue along and head of a wavy cold front stretching from the Great Lakes/Midwest southwestward through the Middle Mississippi Valley and into the Southern Plains. The Storm Prediction Center has outlined an Enhanced Risk of severe weather (level 3/5) from north Texas northeastward into eastern Oklahoma, northwestern Arkansas, and southern Missouri through tonight where the best combination of strong buoyancy and both low-level and deep-layer wind shear are expected to lead to some supercell storms. Storms will likely begin to cluster into the evening bringing more of a large hail and damaging wind threat, though a few tornadoes will remain possible with any remaining discrete/semi-discrete storms, including the potential for a strong tornado. A broader Slight Risk (level 2/5) is in place from the Southern Plains northeastward through the Middle Mississippi Valley/Mid-South and into the Ohio Valley where some more isolated instances of large hail, damaging winds, and a few tornadoes are possible. In addition, a southerly influx of deep moisture from the Gulf of Mexico along with storms clustering/motions increasingly parallel to the frontal boundary will bring the threat of some very heavy downpours and the risk of scattered instances of flash flooding, with a Slight Risk of Excessive Rainfall (level 2/4) overlapping the Enhanced severe risk, and continuing downstream into the Mid-South as storms move eastward overnight. The widespread showers and storms will continue as the front progresses southeastward into the day Friday, with the coverage shifting downstream into eastern Texas eastward through the Lower Mississippi Valley and into the Tennessee Valley/Southeast. Surface ridging over the western Atlantic and into the Gulf of Mexico will keep the supply of moisture flowing northward plentiful, and may result in the boundary slowing somewhat as it progresses, allowing for some storms producing heavy downpours clustering/training along the front. Two Slight Risks of Excessive Rainfall within a broad Marginal Risk over the region are in place where the highest confidence currently exists in the combination of overlapping upper-level energies/storm coverage and wet antecedent conditions for some more instances of scattered flash flooding. This includes portions of central/southern Texas into west-central Louisiana and northeastern Mississippi into northern Alabama and northwestern Georgia. However, complex mesoscale details lead to some uncertainty with the potential these areas could further shift. Some additional severe thunderstorms are also possible over central Texas, with another Slight Risk from the SPC in place for the threat of some large hail and perhaps a tornado. Showers and some thunderstorms will also spread into New England and the Mid-Atlantic along the eastern portion of the front late Thursday and into Friday with some areas of moderate to locally heavy rainfall possible. Some wintry precipitation may mix in north of the front for portions of northern New England. The front will continue southeastward Saturday clearing New England and the Mid-Atlantic by Saturday morning and the Southeast through the early afternoon, bringing an end to shower and storm chances for these areas. However, the front will linger westward through portions of Texas along and near the Gulf Coast westward through South Texas. Yet another Slight Risk of Excessive Rainfall is in place as widespread, heavy rain producing storms cluster along the boundary over increasingly wet antecedent conditions where storms overlap with the prior days' rainfall, continuing the threat for scattered flash flooding. Elsewhere, a clipper system dropping southeastward from Canada into the Upper Midwest/Great Lakes by Friday evening will bring some light to moderate rain/snow shower chances into Saturday. Temperature-wise, above average highs will continue to bring an early taste of Spring to most of the central and eastern U.S. heading into the weekend. However, passing frontal systems will bring temperatures down a bit from some of the more greater anomalies seen today as temperatures for many locations were upwards of 20-30 degrees above average, settling in closer to 5-10 degrees above average. Highs will be below average over the Southwest/Four Corners into the Great Basin and central/southern Rockies, as well as the adjacent Plains with the upper-trough in place. The West Coast into the northern tier of the West (Pacific Northwest/northern Great Basin/Northern Rockies) will be away from the influence of the trough and see more mild, above average conditions. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php