Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 335 PM EDT Tue Sep 15 2015 Valid 00Z Wed Sep 16 2015 - 00Z Fri Sep 18 2015 ...Temperatures will be 10 to 20 degrees above average from the Plains into parts of the Upper Great Lakes... The large scale pattern over the next few days consists of a trough over the West and a ridge over the East. A series of waves will move through the mid- and upper-levels, which will reinforce a surface frontal system spanning from the Intermountain West to southeast Canada. The wave that traverses through through Rockies Wednesday afternoon and evening, will cause the cold front over Montana and North Dakota to pick up pace and surge into the Central Plains on Thursday. Showers and thunderstorms will be possible over parts of the Great Basin, the Central Rockies and the Northern Plains as the front system is nearly stationary. Showers and thunderstorms coverage will become more widespread over the Central/Northern Plains on Wednesday and into the Upper Great Lakes/Upper Mississippi Valley region late Wednesday into Thursday. Rainfall amounts through Thursday are expected to range from 0.50 up to 2.50 inches over the Intermountain West; 0.50 on up to 1.25 inches for the Upper Mississippi Valley/Great Lakes region. Much higher amounts are forecast the Eastern Gulf coast, Florida and the Southeast coastal regions. Numerous showers and thunderstorms over these areas are expected to yield 1.50 to 5 inches over the course of three days. An upper ridge will remain in place over the East through the end of the work week, which will keep conditions for most areas east of the Mississippi mild and calm. For central portions of the CONUS, especially from the Southern Plains through the Upper Great Lakes, will experience above normal temperatures before the cold front makes its way eastward. In some locations the forecast maximum temperatures will be about 10 to 20 degrees above average for mid-September. The 850 hPa temperature anomalies suggest a return of near normal temperatures to the aforementioned areas by the weekend. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php