Area Forecast Discussion
Issued by NWS Fairbanks, AK
Issued by NWS Fairbanks, AK
539 FXAK69 PAFG 182228 AFDAFG Northern Alaska Forecast Discussion National Weather Service Fairbanks AK 228 PM AKDT Tue Jun 18 2024 .SYNOPSIS... Ridging over the Interior is bringing summer conditions to most of northern Alaska. High temperatures will be mainly in the 70s through the rest of the week, with a few 80s in the Yukon Flats today and tomorrow. Isolated to scattered thunderstorms are expected each afternoon. Seasonable and mainly dry conditions are expected for the West Coast and the North Slope as well. && .DISCUSSION... Upper Level Analysis... A closed upper-level low is situated over the Chukchi Sea this afternoon, while broad ridging extends up from Western Canada into Interior Alaska. A shortwave trough is lifting northward toward the central and eastern Brooks Range, continues to support showers and thunderstorms roughly along a line from Huslia to the Yukon Flats. Surface Analysis... A trough extending over much of northwest Alaska is drawing northerly winds across the Chukchi Sea southward through the Bering Strait, with gusty south to southwesterly winds developing along portions of the West Coast and across much of the Western Interior. Despite generally onshore flow along the Arctic coast, stratus and fog continues to mix out through the day. Much warmer conditions with temperatures in the 70s and dew points in the upper 40s to low 50s have allowed for developing scattered to numerous rain showers and thunderstorms in the Eastern Interior. Central and Eastern Interior... Temperatures will peak broadly in the mid to upper 70s this afternoon, with areas in the Yukon Flats likely reaching 80. Scattered thunderstorms continue this evening from the Upper Koyukuk Valley east through the Yukon Flats and northern portions of Fortymile Country. Elsewhere, expecting widely scattered thunderstorms, with isolated thunderstorms possibly moving into the Fairbanks area tonight as they track north from the Alaska Range. A shift to southerly winds is possible behind these storms, which may bring in smoke from the McDonald Fire. Upper-level ridging gradually shifts north as a series of shortwaves try to work northward across the Alaska Range. Expect a slight cooling trend as high temperatures slowly decrease into the low to mid 70s through the end of the week, with thunderstorm activity trending down as well. High pressure builds along the Arctic coast, bringing a shift from southwesterly to northeasterly winds, which could gust up to 25 mph in the Yukon Flats Thursday and Friday afternoon/evening. West Coast and Western Interior... Scattered thunderstorms continue this evening from Galena northward, with isolated to widely scattered thunderstorms elsewhere across the Western Interior. Thunderstorm activity will be lower the rest of the week, with generally isolated thunderstorms limited to the Western Interior. From the northern Seward Peninsula north, a deep upper low keeps conditions cloudy and cool, with a chance of rain (and some snow) showers through this evening. The upper low retreats west over Chukotka for Wednesday, allowing the upper-level ridge to extend west. Temperatures warm up heading into the end of the week, most notably allowing the Kobuk Valley to see highs in the 70s on Thursday and Friday. North Slope and Brooks Range... Northeasterly onshore flow will continue to bring stratus and fog along the Arctic coast each night, with offshore flow just off the surface afforded by the upper low over the Chukchi Sea contributing to clearing skies during the day. The upper low retreats westward through the week as high pressure builds along the coast, bringing deeper onshore flow and more persistent fog/stratus by Thursday. The best chance for thunderstorms in the short term is this afternoon/evening, with widely scattered thunderstorms expected on the south side of the Brooks Range. Otherwise, thunderstorm risk remains isolated and will be confined primarily to the Brooks Range each day. Extended Forecast Days 4-7... Forecast models are in agreement that the ridge in place over the interior will weaken over the weekend. Models diverge early next week, but generally indicate a continuation of near to slightly above normal temperatures across most of northern Alaska. Drier conditions across the interior and West Coast are likely this weekend through the middle of next week. This will bring continued fire weather concerns. Coastal Hazard Potential Days 3 and 4...None. && .FIRE WEATHER... Conditions across the Interior will be a few degrees cooler with 3-5% higher RH than yesterday. Wed will be slightly drier but with similar temperatures to today. There will be slight warming and drying on Thu, with very warm conditions continuing into the weekend. Expect today to be a banner day for thunderstorms with more lightning strikes over Northern AK than what occurred Mon, with the lightning further NE than Mon. Thunderstorms this evening will be isolated across most of northern Alaska except the coastlines, but widely scattered across the Alaska Range, eastern interior, and north of Fairbanks to the south slopes of the Brooks Range. Thunderstorms will be scattered from Chicken to Eagle and from the Yukon Flats west to near Huslia. Expect the scattered thunderstorms to have frequent lightning, brief heavy rain, winds gusting to 30 mph and 1/2 inch hail. Wed will have isolated thunderstorms over much of the Interior through late Wed night, with widely scattered PM thunderstorms east of Tanana and Bettles Wed PM. There could be frequent lightning, gusty winds and small hail with the widely scattered thunderstorms East of Tanana and Bettles. Thu will see isolated thunderstorms over all of the Interior through the day, with widely scattered thunderstorms east of Red Dog to Nikolai. && .HYDROLOGY... River levels on the North Slope continue to fall. No widespread flooding is expected, but will need to keep an eye on slow moving thunderstorms across the Northern and Eastern Interior today where occur over steep terrain. The same goes for the SE Interior and AK Range on Thu PM when increasing numbers of thunderstorms could fire up there. && .AFG WATCHES/WARNINGS/ADVISORIES... AK...Red Flag Warning for AKZ931>933. Dense Smoke Advisory for AKZ840. PK...Small Craft Advisory for PKZ806-854. Small Craft Advisory for PKZ812. Brisk Wind Advisory for PKZ813-859. Small Craft Advisory for PKZ858. && $$ CQ/JC