textproduct: Fairbanks

SYNOPSIS

Broad scale troughing continues today as a low pressure system sits in Gulf of Alaska and a Arctic low tries to dig south over the North Slope. As high pressure builds over Siberia and southeast Canada, a front extending from the Arctic low will push south across the state supporting scattered showers and thunderstorms chances this weekend. Thunderstorms coverage will expand farther south ahead of the front with widespread rain showers expected for the Upper Tanana Valley through Saturday. By early next week, warmer and drier conditions are likely as high pressure settles over the state.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Isolated thunderstorms and scattered showers are expected to continue across most of the Interior throughout the week. Increased thunderstorm activity is possible to the west of Fairbanks this afternoon. Storm chances decrease next week.

- High temperatures will remain in the low to mid 60s through the weekend with a warming trend expected early next week.

- Moderate rain showers are possible for the Upper Tanana Valley beginning this afternoon through the weekend.

West Coast and Western Interior... - Scattered showers and isolated afternoon thunderstorms continue across the Western Interior and parts of YK Delta this week. Showers and thunderstorm chances decrease from north to south through the end of the week.

- Gusty north/northeast winds continue through the Bering Strait today with winds gradually weakening through Friday. Gusts as high as 30 mph are possible.

- Temperatures will remain in the upper 50s to low 60s through the weekend before steadily increasing early next week.

- Patchy fog is possible across the West Coast going into the weekend.

North Slope and Brooks Range... - Slightly cooler than normal temperatures continue across the North Slope with highs in the mid 20s and lows in the mid teens. Temperatures gradually warm going into next week. - East/northeast winds will shift towards the south/southwest by Saturday.

- Gusty north winds through the Brooks Range passes are expected today through Friday. Winds may gust up to 30 mph at times.

- Low clouds and patchy fog continue across the North Slope, with gaps in the clouds expected by Friday. Clearer skies are possible this weekend into next week as winds weaken and offshore flow sets up along the coast.

FORECAST ANALYSIS AND DISCUSSION

For Thursday through Saturday night. Broad scale troughing persists over the state today as a low pressure system sits in the Gulf of Alaska. This low will continue to push southeast through the weekend as a building ridge of high pressure strengthens over Siberia. Along the North Slope, an Arctic trough tries to dig down over the Arctic Coast but is also pushed farther east by the Siberian high. By Friday, a front extending from the Arctic low traverses southeast across the state towards the Alaska Range. Ahead of this front, scattered showers and thunderstorms are expected to continue across the Interior this afternoon, with the Upper Tanana Valley and Alaska Range seeing the greatest chances for wetting rain. Additional widespread rain showers are likely for the Upper Tanana Valley through the weekend as PWAT values increase to near 0.60 inches due to steady moisture influx from the southeast. Winds through the Bering Strait will continue to gust up to 30 mph at times but will gradually subside as the Siberian high moves farther inland. Elsewhere, afternoon gusty conditions are possible across higher terrain and near thunderstorm outflow boundaries.

By early next week, warmer and drier conditions are likely across Northern Alaska as broad scale ridging settles over the state. However, models are hinting at the possibility for a mid-level disturbance to move south from the Eastern Arctic late Sunday. Depending on the exact placement of this low, temperatures could temporarily cool a few degrees early next week as well as support additional scattered showers across the region. Despite this, forecast confidence is still leaning towards a warmer and drier pattern at least through the early parts of next week.

FIRE WEATHER

Scattered showers and isolated thunderstorms are expected to persist through the end of the week, primarily over the Yukon Flats, Fortymile Country, and the Alcan Border before tracking southward on Thursday. While widespread wetting impacts are not anticipated, localized wetting rain is possible where storms linger across the Eastern Interior and where minimum relative humidity values are expected to rise into the mid to upper 30 percent range. Surface winds across the Interior will remain light as the pressure gradient over the Alaska Range weakens. However, a low pressure system is expected to push stronger winds through the Brooks Range passes, Upper Koyukuk Valley, and along the Dalton Highway Summits with gusts up to 30 mph through Friday. Wind gusts up to 25 mph from the east are possible across areas of the Yukon Flats and Fortymile Country. Along the West Coast, thunderstorm chances will transition toward the Northwestern Yukon Delta Thursday afternoon, while strong northeast winds up to 30 mph through the Bering Strait will gradually weaken as an upper-level ridge approaches. Minimum relative humidity values are expected to remain between 30 to 40 percent across most of the area. Temperatures will remain seasonable through the end of the week, with highs in the low to middle 60s for the Interior and upper 50s to low 60s for the West Coast.

HYDROLOGY

Yukon River: River Watch has concluded as of 8 AM Wednesday. Ice continues to move through the channels into the mouth with relative ease and with upstream ice moving unhindered. Residents should still use caution near the banks as the ice run continues to be very dynamic and water levels can fluctuate quickly.

All Flood Watches and Warnings have expired.

St. Mary's: At 840pm Tuesday, flood waters continue to slowly recede. Due to the extensive high water and inundation, this process could take several days. Residents should use caution in and around areas that were flooded.

Emmonak: Waters continue to receed. The roads to the airport remain impassable by vehicle at this time. Residents should use caution in and around high water.

Additional Information: Visit www.weather.gov/aprfc for the latest hydro information.

EXTENDED FORECAST DAYS 4-7

Models are in relatively good agreement with the overall pattern. However, there is a distinct difference amongst them regarding a shortwave moving east/southeast across the Arctic Sunday night into Monday. The EC is most aggressive as it shows it moving south over the Eastern Brooks Range and strengthening to a closed off low. The GFS tracks the shortwave further east, closer to the Al-Can border and keeping it a shortwave feature as it moves SE across the Yukon. The Canadian has it stationed over the northern Arctic Coast, keeping it north of the Alaska Range by the start of the week. This distinctive difference is largely due to the Canadian showing an Arctic Low farther south, allowing the shortwave to get wrapped back into the flow. For now, the forecast is leaning more toward the GFS solution as it shows a better representation of what usually happens with a shortwave taking this track. This pattern will continue to allow for daily thunderstorm chances across the state as a series of weak fronts may extend from the low in the Arctic. The upper-level ridge is expected to remain over the Bering, allowing for more of a northerly influence across the state. This will help limit drastic increases in temperatures, however conditions are expected to remain dry through the first half of next week.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...Small Craft Advisory for PKZ806-854. Brisk Wind Advisory for PKZ807. Small Craft Advisory for PKZ810. Small Craft Advisory for PKZ811. Brisk Wind Advisory for PKZ856.