Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 410 AM EDT Sun Jul 26 2015 Valid 12Z Sun Jul 26 2015 - 12Z Tue Jul 28 2015 ...Warm and humid conditions remain in place across the South-Central U.S... ...A flash flood threat for sections of Florida through early next week... ...Cool and unsettled weather likely from the Pacific Northwest eastward to the Northern Plains... Across the lower latitudes of the country, an upper ridge will remain a fixture over the Southern Plains/Lower Mississippi valley region. Strong subsidence underneath the ridge will ensure little to no threat of precipitation while temperatures soar to the century mark. Combining dew point temperatures in the upper 60s to lower 70s will make conditions quite muggy over this sector of the U.S. The only real relief will be north of this prominent ridge where impulses moving off the Central Rockies should spread convection from the Central High Plains eastward. Looking toward the southeastern U.S., an upper low centered over Florida is forecast to weaken. However, it appears a wavy surface frontal zone should remain intact throughout much of the period which will be the focus for heavy rainfall. Abundant moisture moving out of the tropics will interact with this frontal boundary to support periods of moderate to heavy precipitation. Given previous bouts of heavy rainfall in recent days, there will be an inherent risk for flash flooding where soils are already saturated. The northern stream of the jet will be rather active and amplified the next couple of days. A broad upper trough currently anchoring British Columbia and Alberta will dig south and gather strength over the Pacific Northwest and Intermountain West region. This will allow much cooler air to sink southward from the higher latitudes with temperature anomalies in the 15 to 25 degree range below climatology. Forecast highs on Monday across areas of Idaho and western Montana may not get out of the 50s. In addition to the below normal temperatures, widespread rainfall is likely. The current WPC forecast suggests the heaviest precipitation may straddle the Saskatchewan border with Montana and North Dakota. Given the strength of the system, flash flooding will be possible in some of the stronger convective elements. Additionally, the deepening of the surface cyclone will support an increase in the wind fields across a broad region of the Northern Plains and adjacent locations. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php