Extended Forecast Discussion NWS Weather Prediction Center College Park MD 256 AM EDT Fri Jun 24 2022 Valid 12Z Mon Jun 27 2022 - 12Z Fri Jul 01 2022 ...Overview... Guidance still agrees that a broad upper level ridge over the southern half of the CONUS will be in place through much of the medium range period, forcing storm tracks through the northern tier. A vigorous shortwave through the Upper Midwest/Great Lakes will amplify some as it moves into the Mid-Atlantic and the Northeast early next week. Behind this, amplified ridging will build over the Northwest U.S., and slide into the northern Plains as a closed low/upper trough uncertainly settles over the Pacific Northwest, perhaps by around Wednesday. Meanwhile, monsoonal moisture will continue to persist into the Four Corners region through much of the period, with the best potential for heavier to excessive rains to remain across the south-central Rockies into early next week. ...Guidance Evaluation/Predictability Assessment... Guidance now seem pretty well clustered through medium range timescales, bolstering confidence in the larger scale pattern evolution. The WPC medium range product suite was primarily derived from a composite blend of the 18 UTC GFS and 12 UTC ECMWF/UKMET/Canadian for days 3-5 (Mon-Wed) and then added the GEFS/ECMWF ensemble means into the composite in place of the UKMET for days 6/7 (next Thursday/Friday). Product continuity is decently maintained and individual system forecast differences seem well addressed with this blending process, consistent with predictability. 00 UTC guidance remains in line, but system differences to resolve remain most notable at longer time frames with Pacific trough progression into the Northwest and energetic flow over central Canada. ...Sensible Weather/Threat Highlights... Anomalously high monsoonal moisture for this time of year, likely tied at least in part to Tropical Storm Celia in the East Pacific, will continue streaming into the Four Corners states into early next week. Locally heavy to excessive rainfall will be possible each day, particularly over sensitive burn scar areas and considering the multiple day repeating nature of this activity. The best chance for impactful rainfall looks to be over parts of Colorado/New Mexico with favorable upslope flow interacting with the moisture already in place. A slight risk was maintained across northern New Mexico on the experimental day 4 excessive rainfall outlook centered on Monday where good model agreement overlapped with areas that have seen anomalous rainfall already. Activity then wanes. A cold front should be fairly progressive through the East Monday, but should focus enough moisture and instability to fuel some locally heavy convection. A settling of the front across the Gulf Coast as well as the next cold front dropping into the region, should allow for enhanced rainfall into the middle of next week from Florida to along the Gulf Coast as aided by protracted onshore fetch of moisture. By early next week, temperatures all across the South should finally trend back towards normal. Relatively cooler temperatures with well below normal highs are likely to be most persistent over parts of New Mexico and Colorado given the monsoonal clouds and rain coverage. In the West, ridging through the region should present an excessive heat threat across parts of especially the Northwest into Monday with the above normal temperatures then working through the Rockies, Plains, Midwest and then East/Southeast Tuesday-next Friday as we head into July. Schichtel Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation, experimental excessive rainfall outlook, 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/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml