Extended Forecast Discussion NWS Weather Prediction Center College Park MD 157 PM EDT Sun May 03 2020 Valid 12Z Wed May 06 2020 - 12Z Sun May 10 2020 ...Record heat for the Southwest midweek... ...Unseasonably Cold for the Eastern US Late Next Week and Next Weekend... ...Guidance/Predictability Assessment... The upper level pattern through the medium range period is well-forecast and shows average to slightly above average agreement through next weekend, as there becomes greater amplification of the western US ridge and eastern US trough. Overall for day 3, the fairly good agreement allowed for a multi-model blend as the GFS/GEFS solutions have trended toward the rest of the guidance. By mid/late week and into next weekend, shortwave energy will trek across the central US, spawning a surface low that deepens over the Northeast and New England by day 6/7 as the upper level flow digs and builds over the Great Lakes, central, and eastern US. The day 5-7 blend incorporated more of the 00Z ECENS and 06Z GEFS means with some inclusion of the 00Z ECMWF/06Z GFS for added detail. ...Weather/Hazard Highlights... Record heat will continue in the Southwest through about Thu/Fri before shifting slightly into California as the upper ridge focuses along the West Coast. Temperatures 10-20F above normal should push readings into record territory for most of Arizona and the lower CO River with highest readings near 110F. By contrast, much of the east, and especially around the Great Lakes/Northeast, will see cooler than normal temperatures by about 5-10F through much of the week. An even colder shot of air may accompany the upper trough axis passage into next weekend when temperatures could be 20 or so degrees colder than normal. This may approach record cold levels for some areas but not to the extent of the record heat in the Southwest. Farther south, a cold front will push through all of Florida and into Cuba by the end of the week though in a very modified state. A second cold front is forecast to dip into at least central Florida at the end of the period. Precipitation will generally be light across parts of the CONUS. Stationary front around southern Texas will be a focus for perhaps the heaviest rainfall later in the week, but likely more localized than widespread. Rainfall may expand through the Ohio Valley as the surface low moves into New England late Fri, with some lake-effect/enhanced rain/snow through Michigan. Additional snowfall (though light) is looking more likely at the highest elevations in northern New England late next Friday into Saturday behind the front. Fracasso/Taylor Additional 3-7 Day Hazards information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation, winter weather outlook probabilities and heat indices are at: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml