Extended Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EDT Tue Jul 16 2019 Valid 12Z Fri Jul 19 2019 - 12Z Tue Jul 23 2019 ...Post-Tropical Cyclone Barry to further weaken, but still fuel heavy rains Thursday across the Northeast as a Post-Tropical Remnant Low before exiting to Canadian Maritimes Friday... ...Guidance/Predictability Assessment... Currently (Tuesday morning) the remnant low of what was Tropical Cyclone Barry is slowly tracking north-northeast through southern Missouri spreading enhanced rainfall to parts of the Lower/Mid-Mississippi Valley and western Tennessee Valley. The Weather Prediction Center has assumed responsibility from the National Hurricane Center to issue advisories on inland Barry until the surface circulation has dissipated and an associated flash flooding threat diminishes. Deepened moisture is expected to fuel some lingering heavy rains Thursday across the Northeast before exiting into the Canadian Maritimes Friday. The latest runs of the global guidance still depicts a fair amount of uncertainty through the extended period; therefore, followed suite to the previous forecast and utilized a compromise of the NAEFS and ECWMF ensemble means. Again, the ECMWF and GEFS mean clustered reasonably well with this preferred solution that offers a fairly well established larger scale pattern with much less certainty with embedded smaller scale impulses and local convective focus. ...Overview and Weather Highlights/Threats... Tropical moisture from the remnants of Barry will spread across the northern Mid-Atlantic and Northeast through Thursday as the leading edge of the front tracks offshore. Locally heavy rainfall across these regions may increase the risk for flash flooding, especially in areas of higher terrain and reduced FFG. Temperatures near or above seasonal average are forecast for a vast portion of the southern and central U.S. as ridging remains in place this coming week. Some locations may tie or set new daily high minimum records. Heat indices will be around 105 to 115F, which may lead to some future issuance of heat advisories. A quasi-zonal flow pattern will develop across the northern-tier of the U.S. Throughout this coming week a series of hard to time disturbances will pass through southern Canada and through the northern states. Showers and thunderstorms capable of producing locally heavy convection/MCS activity will sporadically develop and propagate within a wavy frontal/baroclinic zone across the Northern Plains, Upper Mississippi Valley and into the Upper Great Lakes region, then into the Lower Great Lakes and Northeast. Multiple rounds of rain/high rain rates may lead to locally excessive rainfall as the moisture and instability pools along the stalled frontal boundary. Although the model spread for QPF is not as high as previous cycles, it still lower confidence on where and when the highest amounts occur. Guidance continues to suggest the max QPF occurs over the Upper Mississippi Valley and Great Lakes 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