Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 243 PM EDT Sat Aug 11 2018 Valid 00Z Sun Aug 12 2018 - 00Z Tue Aug 14 2018 ...Heavy rain and flash flooding a concern for West Texas... ...Showers and thunderstorms could bring flash flooding to New England southward into the Mid-Atlantic... ...Heat wave continues across parts of the Intermountain West along with critical fire weather conditions... A mid-level closed low centered over Texas will aid in bringing a plume of enhanced moisture across the state. Meanwhile, at the surface, two quasi-stationary fronts will provide focus for fueling showers and thunderstorms. Most of the heavy rainfall can be expected from the Big Bend of Texas to the Dallas-Fort Worth region. For the rest of today, expect a slight risk of flash flooding across the Big Bend region. A marginal risk will also be in place from most of West Texas and into the Red River Valley. By Sunday, a moderate risk of flash flooding is possible for portions of West Texas. As the surface front lifts north as a warm front by Monday, the axis of heavy rainfall will concentrate in the southern portions of the central Plains and into the lower Mississippi Valley. Parts of Oklahoma and Kansas could see flash flooding with this convection; thus, a slight risk has been issued. A mid-level trough is slowly moving eastward and by tomorrow morning, the mid-level low will pinch off and remain over the Ohio Valley. Once again, two boundaries at the surface will focus showers and thunderstorms through the rest of the weekend. For today, portions of the Tennessee Valley into the Mid-Atlantic can expect scattered showers and thunderstorms with heavier rainfall across New England. By Sunday, the axis of heavy rainfall shifts to the Mid-Atlantic southward into North Carolina. The closed mid-level low will drift over the central Appalachians/Mid-Atlantic on Monday--which will persevere this wet pattern for much of the East Coast. Plenty of instability and moisture on tap is expected for the Southwest. Since most of these thunderstorms will be diurnally driven, showers and thunderstorms will increase in coverage during the late afternoon/evening. Flash flooding is a concern especially for regions prone to flooding due to terrain and urban areas. Farther north, a heat wave continues across parts of the Pacific Northwest eastward into the northern Plains. Excessive heat warnings and heat advisories are in place as high temperatures soar to above 100 degrees for these areas. Additionally, because of the oppressive heat and dry conditions, fire weather is a concern for many of these regions. As such, red flag warnings are in place from western Washington to northwest South Dakota along with some parts of northern California, southern Oregon, and northwest Nevada. A strong cold front will move across these regions over the next few days and will relief to the opressive heat. The Pacific Northwest and northern Rockies can expect high temperatures to be in the 80s by tomorrow. On Monday, temperatures across most of the Montana and North Dakota will drop to near normal or below normal. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php