Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 318 AM EST Sat Nov 07 2020 Valid 12Z Sat Nov 07 2020 - 12Z Mon Nov 09 2020 ...Heavy snow to develop over parts of the Sierra, Rockies and Northern Plains... ...Record or near record warmth continues from Northern Plains to Midwest and Northeast/Mid-Atlantic; record cold likely across California and Great Basin... ...Heavy rainfall and strong winds to impact southern Florida as Tropical Storm Eta crosses into the Keys... A potent upper-level low will drive much of the weather impacts across the western U.S. this weekend. A deep area of surface low pressure will generate heavy snow over the Sierra later today before spreading across the Rockies this evening and on Sunday. Snow totals of up to a foot are possible over the Sierra while much higher values around 2 feet are more likely over the Rockies and Northern Plains. Ice impacts will be marginal with this system. A cold air mass will filter into the West behind the aforementioned low pressure system as high pressure settles over the Pacific Northwest. Temperatures will be cold enough this weekend to possibly break records, especially across California and the Great Basin where highs are expected to be between 20-30 degrees below average. Cold air will also descend over the Northern Rockies where highs may be between 20-30 degrees below average on Sunday. Meanwhile, Record warmth will impact areas from the Upper Midwest to the Northeast and Mid-Atlantic this weekend. A dome of high pressure, currently stationed over the eastern half of the country, will expand over the region over the next couple of days. The anomalous heat generated by this expansion will be on the order of 30-40 degrees above average for parts of the Northern Plains and Upper Midwest today, and shrinking into the latter tomorrow. The potential for record breaking temperatures continues over the Midwest and Northeast tomorrow. Elsewhere, an elevated fire risk area is in place over the Central Plains as winds pick up due to an increased pressure gradient out ahead of the western U.S. low pressure system. Tropical moisture will stream northward today ahead of Tropical Storm Eta. Winds, thunderstorm activity and rainfall rates should pick up across the Florida peninsula tonight as Eta approaches Cuba. The heaviest rainfall is likely to occur on Sunday as Eta crosses into the northern Caribbean. There is a Slight Risk of Excessive Rainfall leading to Flash Flooding over southern Florida as a result of the rain associated with Eta. Kebede Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php