Area Forecast Discussion
Issued by NWS Fairbanks, AK
Issued by NWS Fairbanks, AK
697 FXAK69 PAFG 241337 AFDAFG Northern Alaska Forecast Discussion National Weather Service Fairbanks AK 537 AM AKDT Mon Jun 24 2024 .SYNOPSIS... A very active pattern will bring the warmest temperatures so far this summer to much of the Interior on Wednesday and Thursday while a highly unusual Bering Sea low pressure system brings near Gale force winds to the Yukon Delta coast on Wednesday. The heat wave will even extend to the North Slope on Wednesday and Thursday. Thunderstorms will continue to be active this week, with relatively dry thunderstorms possible east of Chena Hot Springs on Wednesday evening. && .DISCUSSION... Analysis and Model Discussion... An amplified and impactful 500 mb pattern is set to impact northern Alaska over the next week. Ridging persists over most of the area with a tight closed low just north of Utqiagvik north of the Arctic Coast. This low will retrograde northward, opening the door for even stronger ridging to build into the Interior and even north to the Arctic Coast. This will bring high temperatures near or above 90 degrees to much of the Interior on Wednesday and Thursday. 80s are even expected north of the Brooks Range approaching the Arctic Coast. By Wednesday morning, a tight and powerful vertically stacked closed low will move to near St. Paul Island. This feature is highly anomalous for this time of year, and models are progging it at 4 standard deviations from normal. This feature will bring near Gale force south and southeast winds to the Yukon Delta on Wednesday morning and 20 mph south and southeast winds south of the Bering Strait. This will bring even more rare elevated surf to the region Wednesday through Friday. As the low transits northward on Thursday and Friday, a sharp boundary will form from the Northwest Arctic Coast to the central Alaska Range. This boundary will be the focus for highly active thunderstorm activity. A shortwave will also bring elevated thunderstorm activity and the possibility of dry thunderstorms east of Chena Hot Springs on Wednesday evening. The 24/00z model suite initialized about 1 decameter too weak on ridging over the Interior at 500 mb. Models are in excellent agreement aloft through Thursday morning. We will use a blend of models for the forecast. We`ll update the Lightning Activity Level forecast to match latest guidance (a general increase, especially Wednesday afternoon in the Eastern Interior) and bump down temperatures a couple of degrees across the Interior tomorrow post cold front passage. Central and Eastern Interior...Hot and dry will be the main story through the work week with isolated thunderstorms and a few areas of widely scattered thunderstorms. Highs will reach into the low 80s Monday and Tuesday and into the mid to upper 80s with some 90s possible on Wednesday and Thursday. Highs will likely remain in the 80s through the weekend. Lows in many locations will struggle to drop below 60. Thunderstorms will be isolated today and tomorrow, but widely scattered tomorrow over the Fortymile Upland and near Eagle. On Wednesday, a shortwave will rotate around the high and possibly spark off widely scattered thunderstorms over the eastern Alaska Range and Fortymile Uplands east of Chena Hot Springs. These thunderstorms look to possibly be mostly dry in nature. Smoke from the wildfires burning in the Tanana Flats will likely move into Fairbanks this morning. Smoke may be dense at times, though conditions should improve by Tuesday night at the latest. West Coast and Western Interior...Strong ridging over the Interior and the influence of the low in the Bering Sea over the West Coast will create a mix of conditions over the area over the next week. As the low moves north, expect near Gale force winds and some rain along the Yukon Delta coast on Wednesday. In the Interior, highs will be in the mid 70s to lower 80s under mostly sunny skies with areas of smoke near active fires, with temperatures trending upwards through Wednesday. Lows will also get warmer each day through Thursday. Thunderstorms will be widely scattered near McGrath this afternoon and from McGrath to Lake Minchumina on Tuesday. Storms will be isolated across the rest of the Interior on Tuesday. Wednesday and Thursday look to bring additional isolated thunderstorms. North Slope and Brooks Range...Patchy fog and low stratus along the coast this morning will become less and less extensive the next couple of nights as the closed low aloft moves offshore and is replaced with ridging. Temperatures will rise each day, with a full on North Slope heatwave expected starting Wednesday. Highs will be in the 80s inland, with 60s and 70s along the coast Wednesday and Thursday. Strong thunderstorms are possible Thursday over the western Brooks Range. Otherwise, thunderstorms will be isolated over the eastern Brooks Range each afternoon. Coastal Hazard Potential Days 3 and 4...The aforementioned low pressure system in the Bering Sea will bring elevated surf 1 to 3 feet above the normal high tide line along the Yukon Delta coast as well as south facing shorelines south of the Bering Strait including Nome. Water will be elevated Wed-Fri with multiple water level peaks as storm surge values remain fairly constant and tides go in and out. && .FIRE WEATHER... Fire weather continues to be a concern with hot and dry conditions and active thunderstorm days all in the forecast. Today, expect highs in the mid 70s to low 80s across the Interior. RHs will reach critical values (<25%) east of Delta Junction. Tuesday will be a few degrees warmer yet, though RHs will generally remain above critical values. Wednesday and Thursday are the real scorchers with highs approaching 90 and min RHs 20-25% east of Tanana. Could see Red Flag or near Red Flag conditions for hot/dry/windy Thursday and Friday east of Galena. Otherwise, winds will remain below 15 mph. Thunderstorms will be active each day this week. Today, expect widely scattered thunderstorms from McGrath south to the Western Alaska Range and isolated thunderstorms elsewhere south of the Brooks Range and east of Ruby. Tuesday will see widely scattered thunderstorms from McGrath to Minchumina and over the Fortymile Uplands with isolated storms across the rest of the Interior and eastern Brooks Range. Wednesday will feature widely scattered thunderstorms across the eastern Alaska Range and Fortymile Uplands. These storms look to be drier in nature under the strong ridge. Isolated storms are expected across the rest of the Interior on Wednesday. Thursday and Friday have the potential to be big lightning days, with most of the activity focused on the boundary between the ridge and the influence of the low in the Bering Sea. && .HYDROLOGY... Recent heavy rains have led to higher water levels along the Fortymile River, but drier conditions expected over the next several days will allow water levels to fall this coming week. Glacial fed rivers including the Tanana may begin to rise as warming temperatures lead to increased high elevation snowmelt. && .AFG WATCHES/WARNINGS/ADVISORIES... AK...None. PK...None. && $$ CHRIEST