Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 416 PM EDT Fri Aug 16 2019 Valid 12Z Tue Aug 20 2019 - 12Z Sat Aug 24 2019 Recent model guidances have begun to indicate the possibility of a rapidly intensifying cyclone moving toward or making landfall over southeastern Alaska by next Tuesday into Wednesday. However, both the 12Z GFS and Canadian models have backed off quite as the surface low fails to phase with the upper low dropping south from the Gulf of Alaska. The latest from the 12Z ECMWF retained the rapid intensification scenario. Given the uncertainty indicated by the models, the plan was to incorporate more of the ensemble means for days 4 and 5 to handle this system. This yields a weaker cyclone on the WPC prognostic charts, although the deep solution indicated by the 12Z ECMWF cannot be ruled out. Heavy rain is expected to impact southeast Alaska Tuesday into Wednesday in association with this system. Should the cyclone intensify more rapidly than forecast, high winds would be possible over the coastal sections and on higher elevations. Farther west across the Aleutians, a weakening occluded cyclone, partially originated from Tropical Storm Krosa over Japan, will track eastward along/near the Aleutian island chain. Model solutions agree reasonably well that the cyclone will continue to weaken as it reaches the Alaska Peninsula by late next week. The precipitation associated with this system is not expected to be heavy. A blend of the 00Z EC ensemble mean and the 12Z GEFS mean, together with a smaller portions of their deterministic solutions, were used to generate the WPC pressure and wind fields for days 6 to 8. Kong Additional 3-7 Day Hazard information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php - Heavy rain across portions of the Alaska Panhandle, Tue-Wed, Aug 20-Aug 21. WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html