Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 258 PM EST Tue Feb 27 2018 Valid 00Z Wed Feb 28 2018 - 00Z Fri Mar 02 2018 ...Increasing chances for flooding issues from the Arklatex eastward into the mid-South... ...Heavy rain and snow expected from central California up into the Pacific Northwest... ...Rather low snow levels could bring wintry precipitation close to the northern California coast... With a broad upper ridge maintaining its dominance over the eastern Pacific waters, multiple systems are primed to slide down the West Coast with eventual transition toward the center of the country. Meanwhile, the northern branch of the jet stream will also be quite active as a series of smaller-scale impulses could be impetus for precipitation, particularly given any interaction with mid-latitude features. As a robust upper low ejects out of southern California, moisture return will be on the increase across the southern Plains resulting in a well defined dry line across the region. West of this boundary, dry and windy conditions should prevail, thus enhancing the threat for wildfires. During the next couple of days, an area stretching from southeastern Arizona out toward the southern high Plains are in elevated to critical risks for wildfires per the Storm Prediction Center outlook. On the other side of the spectrum, heavy rainfall will spread north of the advancing warm front with the activity concentrating from the Dallas/Fort Worth metro area eastward through much of Arkansas and into vast sections of the mid-South. Based on the latest forecast, several inches of rainfall are possible from roughly Little Rock, Arkansas eastward into Tennessee, generally just south of interstate 40. Given recent heavy rainfall over the region, flooding and flash flooding will be likely within any training bands of convection or areas where storms tend to repeat over the same areas. Soils remain saturated so it will not take a significant amount of precipitation to cause hydrologic issues. While this system does accelerate and become more stretched out in nature, there may be some interaction with a trough dipping down over the Great Lakes. A great deal of uncertainty exists with this scenario but it is worth monitoring given the few waves of low pressure to track over the Ohio valley and across the coastal mid-Atlantic. Overall, the number of disturbances traversing the upper Midwest into New England will keep conditions unsettled throughout the week. Several inches of snow are possible across northern Maine while a separate axis of snow can be found back over the upper Great Lakes, albeit with lighter amounts. On the heels of the first closed low exiting the southwestern states, an even more expansive circulation dives down from the Gulf of Alaska. Strong lift accompanying this system will drive abundant precipitation anywhere from central California northward into British Columbia. As usual, the local terrain can expect heavier amounts given favorable orographic lift. More specifically, the current forecast suggests 1 to 2 feet of snow across the Shasta, Trinity, and Siskiyou ranges of extreme northern California as well as over the Olympics, Cascades, and Blue Mountains. Even higher amounts are possible across the Sierra Nevada ranges with up to 3 feet in the forecast. With snow levels likely dropping to around 2000 feet, some of the accumulations could easily edge toward the coastline. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php