Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 442 AM EDT Tue Jul 28 2015 Valid 12Z Tue Jul 28 2015 - 12Z Thu Jul 30 2015 ...Severe thunderstorms possible across the Upper Midwest/Middle Mississippi Valley... ...A threat for flash flooding exists across sections of northern New Mexico on Wednesday... ...Above normal temperatures to prevail across the West Coast... A strong upper trough currently moving from the Northern Rockies toward the Upper Midwest will continue to bring much cooler weather to the region with temperatures approximately 15 to 25 degrees below normal today. This generally equates to highs in the 60s accompanied by cool comma-head precipitation. Slow deepening of the surface cyclone will support an increase in the pressure gradient, thus enhanced the broader scale wind field. Meanwhile, the advancing cold front currently moving through the eastern Dakotas will be the site for active convection where a severe thunderstorm threat exists from Minnesota and western Wisconsin down to Iowa. Given the large amounts of moisture advecting northward from the Gulf of Mexico, expect locally heavy rainfall capable of producing flash flooding over the Middle Mississippi valley region. Further in time, the strength of the cold front will weaken as the core of the upper trough lifts well into Ontario. Expect scattered showers and thunderstorms along the aforementioned front as it moves toward the Great Lakes and Ohio Valley. Additional areas of unsettled weather are over the state of Florida where remnant energy from an upper low remains in place. This coupled with strong low-level convergence along sea breeze induced boundaries will support periods of heavy rainfall, particularly across the west side of Florida. Through the next couple of days, WPC expects 1 to 3 inches of rainfall across west-central Florida. Looking back toward the Southern Plains, a persistent upper ridge which has maintained hot and humid conditions will help draw abundant monsoonal moisture into the Four Corners region. The most defined surge should occur by Wednesday evening into the overnight hours where a concentrated axis of convection will move from New Mexico toward the adjacent Texas/Oklahoma panhandles. Some of the heavier rainfall may enhance the threat for flash flooding. Elsewhere, a building upper ridge along the West Coast will bring above normal temperatures to the region. Current forecast temperature anomalies suggest readings about 10 to 15 degrees above normal. This would support highs in the 100 to 105 degree range across the interior valley locales. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php