Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 436 AM EDT Mon Jul 27 2015 Valid 12Z Mon Jul 27 2015 - 12Z Wed Jul 29 2015 ...Cool/unsettled conditions to prevail from the Upper Intermountain West to the Upper Midwest... ...Abundant heat and humidity to continue over the Southern Plains... ...More wet weather in store for Florida this week... A strong upper trough digging into the Pacific Northwest will slide eastward toward the Northern High Plains the next 24 hours. As this occurs, a surface cyclone is forecast to continually deepen attaining a rather low pressure for the middle of the summer. This should be quite the dynamic system with heavy rainfall, severe weather, and a strong wind field given the large pressure gradient at hand. Moisture availability will not be an issue as large fluxes of Gulf moisture will work their way up the Great Plains in advance of this powerful system. A robust area of convection is expected along the leading cold front with all severe types possible per the latest Storm Prediction Center outlook. Meanwhile, a broad region of comma-head precipitation is likely on the back side of the system which could support lengthy periods of moderate to heavy rainfall. The forecast from WPC suggests a widespread 2 to 4 inches of precipitation from northeastern Montana into northwestern North Dakota and extending into adjacent portions of southern Saskatchewan. These heavy forecast amounts will enhance the risk for flash flooding. Besides the stormy conditions, much cooler air dropping down from western Canada will lower temperatures to 15 to 25 degrees below normal. Highs in the mid to upper 50s are likely this afternoon over western/central Montana. Elsewhere, a prominent ridge across the Southern Plains will continue to support hot and humid conditions through mid-week. Strong subsidence occurring underneath the ridge should squash any major threat for precipitation. The exception to this rule will be closer to the High Plains where a low-level convergence zone along the lee trough may help spark afternoon/evening convection. Otherwise, expect temperatures nearing the century mark accompanied by rather humid conditions. While a core of the upper low has weakened over the state of Florida, there is some remnant energy lingering across the region. These energetics combined with surface convergence along sea breeze boundaries will aid in deep convection, particularly during the peak diurnal heating. Given the heavy rainfall in recent days, flash flooding is possible over regions with saturated soils. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php