Extended Forecast Discussion NWS Weather Prediction Center College Park MD 1200 PM EDT Wed Oct 23 2019 Valid 12Z Sat Oct 26 2019 - 12Z Wed Oct 30 2019 ...Overview and Guidance/Uncertainty Assessment... The model spread is significant during the extended period. For nearly a week, the GFS solution has been consistently progressive with energy tracking across the CONUS. This continues to be the case with this morning's cycle and the NAEFS and Ensemble means are in this camp as well. The CMC and UKMET solutions are closer to the ECWMF and the its ensemble means where it has a deeper and slower progression of the low/trough exiting the Southwest into the central U.S. Therefore a compromise of those 4 pieces of guidance was utilized in this forecast issuance. The nearly +3 height anomaly over Alaska/Gulf suggests much cooler temperatures from the Pacific Northwest to the Northern/Central Plains and the aforementioned blend supports this. ...Weather Highlights/Threats... A favored slower evolution over the Southern Plains/Lower MS Valley allows for a longer and continued lead fetch of deep/tropical moisture out of the Gulf of Mexico. Several inches of rain are possible from the Gulf Coast states to the Ohio Valley with the main supporting/ejecting system trending more northeastward than earlier guidance. This occurs a weak wave of low pressure slows the front through the mid-South. The boundary should slowly push northeastward through the Ohio Valley this weekend and weaken as it encounters ridging to its east and as a stronger front to its west largely absorbs/overtakes it. In the West, incoming cold front late this week into the weekend will be mostly cut off from the moisture supply but will still manage to spread moderate precipitation including mountain snows, especially over the n-central Rockies as enhanced by upslope fetch. Rain/snow potential may also spread northeastward next week across the n-central U.S. with slow system progression and emergence into the Plains. Temperatures will trend much colder than average in the West behind the lead cold front this weekend, with max temperatures 10-25 deg F below average Sunday into next Tuesday along/east of the Divide from western Montana to eastern Colorado as the front whooshes southward. Above average temperatures will be confined to the Southeast to the south and east of the front. Florida will continue to see high temperatures well into the 80s with some record highs possible this weekend. Campbell 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