Hydrometeorological Discussion
Issued by NWS
Issued by NWS
090 AGUS74 KWCO 171524 HMDNWC National Hydrologic Discussion - EXPERIMENTAL NWS National Water Center - Tuscaloosa AL 1015 AM CDT THU OCT 17 2024 .Synopsis... Ongoing river flooding continues for the Central Florida Peninsula... Flooding will be possible late this week into the weekend over the Southern Rockies into the Southern Plains...Flooding impacts possible in Puerto Rico and the USVI... Rainfall in Washington... .Discussion... Florida Peninsula... Moderate and major river flooding will continue across the central FL Peninsula through the end of this week. The St. Johns River and the Withlacoochee River are forecast to continue to rise through the weekend. Due to the flat terrain and sandy soils of this region, many recessions are expected to be slow, though with no significant rainfall forecast in the next week flows will continue to route and recede unimpeded. Southern Rockies into the Southern Plains... Multiple rounds of rainfall day 2 (Fri) through day 4 (Sun), will bring the potential for localized flash, urban, and arroyo flooding to portions of northeast NM into the western TX Panhandle. Though antecedent conditions are dry (top layer soils 5 - 25% RSM (NASA SPoRT)) and streamflows are normal to below climatological normals (USGS), storms will bring ample anomalous moisture and potential for localized flooding, especially in recently burned areas. The National Water Model (NWM) Medium-Range Forecast (MRF) has been consistently signaling small stream responses in this region, with the largest responses east of Santa Fe, NM toward Amarillo, TX and into southeast CO along the NM/TX/OK/CO state intersections. Confidence in isolated flooding impacts is increasing in this region, but specifics in terms of magnitude remain uncertain. Puerto Rico and the USVI... Heavy rainfall associated with Invest 94L may result in localized flooding impacts in Puerto Rico and the U.S. Virgin Islands, day 2 (Fri) through day 3 (Sat). Though there remains uncertainty with tropical development, heavy rainfall is expected, and localized rapid river rises, urban flooding, and mudslides are possible, particularly in areas of steep terrain. Washington... An atmospheric river will bring rainfall to the region day 2 (Fri) through day 4 (Sun). Flooding impacts are not expected with this rainfall due to the dry to droughty antecedent conditions that prevail. There will likely be in-bank small stream responses associated with this rainfall. //Ayala $$