Short Range Forecast Discussion...amended NWS Weather Prediction Center College Park MD 1216 AM EST Fri Nov 17 2017 Valid 12Z Fri Nov 17 2017 - 12Z Sun Nov 19 2017 ...Heavy precipitation is expected across the Northwest, Intermountain West, Upper Midwest, and Northeast... The main attraction this period is a complex low pressure area/set of frontal waves moving from Wyoming and the central Plains which intensifies as it moves by the southern Great Lakes on an east-northeast heading. In advance of this system, record high temperatures and critical fire weather conditions (per guidance from the Storm Prediction Center) are expected across southeast New Mexico and northwestern Texas on Friday in the wake of a dry line caused by very warm and dry downsloped air moving off the southern Rockies. Cold air aloft and onshore flow from the Pacific brings in heavy rain and higher elevation snow across the Intermountain West today. A building surface high over the Great Basin in the cyclone's wake could lead to gusty offshore winds across southern California late Friday and Saturday. Once the strengthening low taps moisture from the Gulf of Mexico Friday night, heavy rain develops across the Upper Midwest Friday night which streaks east-northwest into the Northeast late Saturday. By Sunday morning, lake effect snows are expected in the lee of the Great Lakes which are expected to spread into the central Appalachians. The system brings cooler air in its wake through the central Plains late Friday night, Mississippi Valley by late Saturday, and into the East on Sunday as surface high pressure builds into the southern Plains. On the heels of this system, a strong disturbance aloft moves towards the Pacific Northwest which by Sunday morning brings heavy rain to the Olympic Peninsula of Washington and the northern Washington Cascades. Roth Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php