Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 331 PM EDT Sat Aug 10 2019 Valid 00Z Sun Aug 11 2019 - 00Z Tue Aug 13 2019 ...Hot and humid conditions across the South and heavy rain for parts of the central and northwest U.S. through the weekend... A rather active weather pattern is forecast to continue across parts of the Plains and the interior Northwest U.S. for the weekend. An anomalously strong upper-level low for this time of the year is moving inland from the eastern Pacific will move over the Pacific Northwest through tonight and early Sunday. This is expected to result in a corridor of locally enhanced rainfall from central Oregon to western Montana. Ahead of this system will be gusty winds which will produce elevated fire weather conditions before a cold front gradually arrives. As the stronger energy arrives along with the cold front, locally heavy showers and thunderstorms will evolve, including a threat for some severe weather. Flood watches are also in effect for parts of northern Washington, northern Idaho, and western Montana concerning the expected heavy rainfall. Multiple rounds of heavy rain and strong thunderstorms are likely across the central and northern Plains through Sunday as multiple surface lows track across the region. Locally a few inches of rain will be possible as multiple complexes of strong thunderstorms develop and track across the region. On Monday, the waves of low pressure along with multiple fronts will advance east across the Midwest which will bring heavy showers and thunderstorms across this region. Some flash flooding concerns will exist all across the central to the northern Plains and also the Midwest going through Monday. Much cooler temperatures will also gradually spill out of the Northwest and across the northern Plains in behind a cold frontal passage. Across the Four Corners region, monsoonal moisture will also continue to produce diurnally driven showers and thunderstorms through the weekend, some of which may be heavy at times, and especially over the higher terrain. Some localized flash flooding will be possible here too, and especially over and near any burn scar locations. Elsewhere, a strong upper-level ridge of high pressure anchored over the south-central U.S. will result in very hot and humid conditions from the southern Plains eastward to the Deep South where heat advisories, and even a small area of excessive heat watches are in effect. Afternoon highs in the mid 90s to low 100s, and dewpoints well into the 70s will result in very high heat-indices that may reach as high as 110 degrees. Overnight temperatures will also be quite warm, with lows remaining near or above 80 degrees near the coast and mid-upper 70s inland. Across the Ohio Valley, Mid-Atlantic and Northeast, mostly dry and pleasant weather is expected going into early next week with temperatures near normal. One exception will be parts of northern New England this evening where some showers and few thunderstorms will be possible. Temperatures across this region will also be a little below normal over the next couple of days. The next threat of rain will come late Monday across parts of the Ohio Valley as the upstream shower and thunderstorm activity over the Midwest advances farther east. Orrison Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php