Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 654 PM EDT Thu Jun 29 2023 Valid 12Z Mon Jul 03 2023 - 12Z Fri Jul 07 2023 ...Overview and Guidance Evaluation/Preferences... The period starts Monday with a weakening low pressure system just to the south of the AK Peninsula with a second developing system dropping in from the far western Bering Sea. The initial low should lift north and weaken over Bristol Bay by Tuesday as the other low deepens considerably and settles over or south of the Aleutians through much of next week. A strong ridge over western Canada should keep the low from moving too much, though there is quite a bit of uncertainty late in the period. The guidance agrees on this overall pattern/setup, but varies on placement and timing of the later low near the Aleutians the second half of the period. The GFS is notably faster and farther north, wanting to wrap this low northward into Bristol Bay around next Thursday-Friday, while the ECMWF and CMC keep is near or south of the central/eastern Aleutians through much of the period. There's better agreement in the ensemble means towards the ECMWF and CMC, so the blend for today leaned heavily towards the 12z ECMWF/CMC and the ensemble means. Elsewhere, a deep upper low meandering over the Arctic may bring some lowering heights into the North Slope/Brooks Range regions but otherwise, the rest of Alaska looks rather quiet with ridging holding strong over Southeast Alaska and some weak troughing through the Interior. ...Weather/Hazards Highlights... The initial low pressure system has potential to bring moderate to locally heavy rain threats to parts of the southern Coast Region, with models focusing the highest rainfall over Kodiak Island and the Kenai Peninsula. Gusty winds (40-50 knots) may accompany this system as well in and around Cook Inlet. The next system mid next week should usher in another round of moisture/rainfall with potential for at least locally moderate to heavy rainfall, but uncertainty remains very high in the details. Temperatures should start well above normal for much of the northern half of Alaska but trend considerably cooler through next week, with the exception of the Yukon Flats region and far eastern Interior. Southern Alaska and into the Aleutians should be below normal through the period as deep upper lows parade through. Strong ridging over Southeast AK should keep temperatures pleasant and warm in that region through much of next week. Santorelli Hazards: - Heavy rain across portions of mainland Alaska, Sun-Mon, Jul 2-Jul 3. 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 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