Alaska Extended Forecast Discussion National Weather Service College Park MD 657 PM EDT Thu Jul 3 2025 Valid 12Z Mon 07 Jul 2025 - 12Z Fri 11 Jul 2025 ...Ongoing hazardous heat across Northern Alaska Sunday moderates into Monday... ...Heavy rain likely across the southern Panhandle on Tuesday... ...Synoptic Overview... The heat wave across northern Alaska through the 4th of July weekend will abate on Monday and promptly reverse to a cooler than normal temperature regime across that portion of Alaska through the remainder of the upcoming workweek. A strong rex block resulting in anomalously strong ridging aloft across northern Alaska will break down as a sharp trough digs southward from the Arctic Ocean Monday. The trough will expand southwestward, becoming positively tilted, while stalling across northern and western Alaska through the rest of the workweek, allowing cooler than normal temperatures to persist across much of western Alaska as well. This positively tilted trough pattern will guide multiple upper level lows embedded in the subtropical jet over the north Pacific northeastward into the Gulf and into the Panhandle. This will make for rainy periods on Tuesday and potentially again on Friday in the Panhandle, with relative breaks in the rainfall on the days in between. Onshore flow through the period should keep things cloudy across much of the state, including the Panhandle. ...Guidance Evaluation and Preferences... While the upper level pattern will be active for this time of year, the guidance remains as normal...generally in agreement through Day 5/Tuesday, then rapidly disagreeing into the end of the week. The disagreements generally stem from differences in how quickly any subtropical disturbances track into the Panhandle, as well as how deep the northern and western Alaska trough gets. Due to these disagreements, a standard model blend was used. No obvious standout models among the primary 3 (CMC, GFS, EC) were noted, so a blend of the 3 was used for Days 4 and 5 (Mon and Tue), followed by a gradual blending towards the ensembles by Day 8/Fri. Since the ensembles all still had the general pattern described above well-portrayed, a small remnant of the deterministics was left in the blend to hint at more details by the longer-range period. ...Weather/Hazards Highlights... Hazardous heat is expected to continue into Sunday across much of northern Alaska, the final day of a multiple-day heat wave for the 4th of July weekend. Temperatures south of the Brooks Range are expected to soar well into the 80s, perhaps near 90 in a few isolated areas on Sunday. As an Arctic trough moves in on Monday, the heat will abate significantly on Monday, with the warmest temperatures near 80 possible in northeast Alaska south of the Brooks Range. In coordination with AFG/Fairbanks, AK WFO, the Hazardous Heat timing was trimmed to just Sunday July 6, and left out of Monday due to the aforementioned cooling expected on Monday. Heavy rain from a potent low in the subtropical jet is likely to impact the southern Panhandle on Tuesday. The low center will track across the northeastern Panhandle and into the Yukon, leaving a prolonged period of onshore and upslope southwesterly flow off the Pacific for the southern Panhandle. This will result in rainfall totals of 2-3 inches for the Tuesday and Tuesday night period, with lesser amounts both Monday night and Wednesday. && Wegman 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