Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Wed Apr 02 2025 Valid 00Z Thu Apr 03 2025 - 00Z Sat Apr 05 2025 ...Life-threatening, catastrophic, and potentially historic flash flood event begins for the Lower Ohio Valley and Mid-South... ...Major severe weather outbreak expected for the Mid-South through tonight with multiple intense tornadoes possible... ...Late season winter storm continues through tonight for portions of the Northern Plains/Upper Midwest with heavy snowfall expected... ...Unsettled weather persists over the West as an upper-level trough passes over the region... ...Critical fire weather conditions continue for portions of the southern High Plains through this evening... A powerful Spring storm system will bring a barrage of life-threatening weather hazards including flash flooding and strong tornadoes to portions of the Lower Ohio Valley and Mid-South through the evening and into the overnight hours. The flash flood threat, which is just now beginning to materialize, is only the beginning of a multi-day catastrophic and potentially historic heavy rainfall event. A deepening upper-level trough and accompanying strong low pressure/frontal system will continue its eastward push through the Midwest, Mississippi Valley, and southern Plains. Extremely impressive dynamics given very strong upper-level and lower-level wind fields, as well as a deep influx of boundary layer moisture flowing northward from the Gulf, will help support a broad warm sector featuring widespread, intense thunderstorms stretching from the Great Lakes southwest through the Middle Mississippi/Lower Ohio Valleys, Mid-South, ArkLaTex, and Southern Plains. The Storm Prediction Center (SPC) maintains a High Risk (level 5/5) of severe weather across portions of the Mid-South and Lower Ohio Valley where the most favorable overlap of strong upper- and lower-level shear and instability will likely lead to an outbreak of tornadoes, including multiple intense tornadoes, as well as very large hail and significant damaging winds. A broader Enhanced Risk (level 3/5) covers the rest of the region where a more scattered but still significant threat of tornadoes, large hail, and damaging winds exists. Unfortunately, this severe threat will be compounded by the beginning of a life-threatening flash flood event. Strengthening upper-level ridging to the east will help to slow the progression of the eastward moving cold front, increasing the chance of repeated rounds of storms as they begin to move more parallel to the stalling boundary. The blocked flow will also help to maintain a supply of plentiful Gulf moisture helping to foster very-efficient, intense downpour producing storms. A Moderate Risk of Excessive Rainfall (level 3/4) remains in place this afternoon, overlapping much of the SPC High Risk from the Lower Ohio Valley southwestward into the Mid-South where the greatest potential exists for several inches of rainfall and scattered to numerous instances of flash flooding through the evening and overnight hours. The front will become nearly stationary across the region Thursday leading to an even greater risk of significant heavy rainfall totals. The repeated rounds of rainfall will lead to increasingly saturated soils, and could bring additional rainfall over areas already experiencing flooding. For these reasons, another Moderate Risk is in place Thursday for the Lower Ohio Valley/Mid South to the ArkLaTex with an embedded High Risk (level 4/4) from western Kentucky to northeastern Arkansas where widespread, life-threatening flash flooding is expected. The front will remain stalled into the weekend with Moderate Risks already in place for Friday and Saturday. This event will bring potentially historic amounts of rainfall, with some locations possibly seeing as much as 10-15"+ of rain through the weekend. Communities throughout the area should prepare now for the possibility of long duration and severe disruptions to daily life given the expected extreme rainfall and flood risk. Additional severe thunderstorms are also expected on Thursday and Friday. On Thursday, The SPC maintains a broad Slight Risk (level 2/5) from the Mid-Atlantic southwest into the Southern Plains, and introduced an Enhanced Risk (level 3/5) from the ArkLaTex to Western Tennessee for the threat of damaging winds, large hail, and a few tornadoes. On Friday, a Slight Risk of severe weather is highlighted from portions of the Ohio Valley southwest to central Texas, with an Enhanced Risk from portions of southern Missouri to far northeast Texas. Similarly to Thursday, all severe hazards are possible, including a few tornadoes and very large hail. Meanwhile, a winter storm continues through tonight in the colder airmass north of the system, with a band of heavy snow forecast along and to the north of the surface low track from the eastern Dakotas into northern Minnesota. Several more inches of snow are expected before the storm wraps up by Thursday morning, with the heaviest totals most likely along the northern shore of Lake Superior. Gusty winds may lead to areas of blowing snow and very difficult travel conditions. The warm front associated with the same system responsible for the snow across the Northern Plains and Upper Midwest will also bring wintry precipitation to areas of the interior Northeast/New England tonight into Thursday. Some light to moderate snow and ice accumulations are possible (especially for the higher mountain elevations and portions of northern Maine) before warmer air moves in and changes most precipitation over to plain rain. Like a broken record, wintry weather continues for another couple of days across much of the Interior West as embedded perturbations round the broad upper-level trough over the region. Some moderate snow totals will be possible for higher elevations of the mountain ranges across the Pacific Northwest, Great Basin, northern/central Rockies, and Four Corners through tonight. Western areas will see the snow taper off by early Thursday while the focus shifts to the northern/central Rockies and Four Corners region. A frontal passage across the northern Rockies and an area of low pressure east of the central Rockies will help to enhance upslope flow and bring some heavier snow totals to the mountains, with some snow also expected for adjacent portions of the northern/central High Plains. In the wake of a dry cold front, strong, gusty winds, low humidity, and dry fuels are resulting in critical fire weather conditions across portions of the southern High Plains this afternoon and evening. Red Flag Warnings remain in effect for parts of southern New Mexico and western Texas. The threat of fire weather remains elevated on Thursday, but won't be as high as today. An amplifying pattern with mean ridging building over the eastern U.S. and the noted troughing over the central/western U.S. will favor warmer, much above average temperatures to the east and cooler, much below average temperatures to the west through late week. Some of the greatest anomalies will be from the Southern Plains eastward through the Southeast, where highs into the 80s and low 90s may reach daily record-tying/breaking levels. Well above average highs into the 70s to low 80s for the Midwest this afternoon will fall into the 50s and 60s Thursday following a cold front passage. Highs in the 50s and 60s for the Mid-Atlantic/Northeast will warm into the mid-60s to low 80s on Thursday as the ridge builds northward. Areas of the Central/Northern Plains will remain cooler behind the cold front with highs ranging from the mid-30s to the mid-50s. In the West, forecast highs generally range from the 40s in the Interior West, the 50s in the Pacific Northwest, the 50s and 60s in California, and the 60s to low 70s in the Desert Southwest. Miller/Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php