textproduct: Fairbanks

SYNOPSIS

For the Interior, hot and dry continues for the solstice weekend, with thunderstorms ongoing across much of the Interior. The simple message is keep an eye to the sky, watch for gusty outflow winds, and stay hydrated. Along the west coast and North Slope, an arctic front is moving ashore Saturday, bringing a low stratus layer, cooler winds, and 20 to 30 knot southwesterly winds for the marine zones, impacting aviation and maritime operations.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Highs continue to increase across the area over the weekend with widespread upper 70s to upper 80s. The warmest temperatures continue to be across the Yukon Flats with a Heat Advisory in effect thru Sunday.

- Thunderstorms are ongoing across much of the Tanana Valley and Alaska Range. Further north we will see isolated thunderstorm activity, with an uptick in the Yukon Flats Sunday.

- Increasing rain chances are favored moving into early to mid next week, although there is still uncertainty on any exact rainfall totals.

West Coast and Western Interior...

- Temperatures remain seasonably cool along the West Coast, with temperatures in the 50s to 60s. In the Western Interior, highs will likely rise into the upper 70s.

- Thunderstorms continue in the Upper Kuskokwim and Lower Yukon Valleys today and Sunday.

North Slope and Brooks Range..

- An Arctic front edging its way southeastward along the Western Arctic Coast will continue to spread across the North Slope this afternoon, bringing cooler conditions and northwesterly winds in its wake.

- Northern Brooks Range valleys are expected to warm into the 70s to near 80 today before falling into the 50s Sunday behind the front. - Isolated thunderstorms will be possible today across the Eastern North Slope and will be more predominant in the southern Brooks Range on Sunday and into next week.

FORECAST ANALYSIS AND DISCUSSION

Starting out Saturday morning, a few features were present across the state. Starting in the north an arctic front was making landfall, expected to move southeast through the day. Expect some rain/snow along the North Slope Coast, with cooling temperatures and a low stratus layer bringing IFR to most of the western coast. This feature will come into play more over the next 24 hours, becoming a weak stationary frontal boundary stalled over the Northern Interior. Second, a closed low was just west of the southwest portion of the state, drifting south, merging with a system in the west Gulf of Alaska. Lastly, a mid-level ridge continues to build across the Eastern Interior, helping to bring hot temperatures and low relative humidities.

Moving into impacts, we are still expecting a heavy lightning day across much of the interior this Saturday afternoon, with thunderstorms ongoing over much of the area. For the White Mountains into the upper Tanana Valley/Fortymile, these systems in particular are slow moving, sticking to the higher terrain, moving west and north towards Fairbanks through the late afternoon. For most of the interior north to the Brooks Range, isolated thunderstorms could crop up. Sunday, most thunderstorm activity likely shifts a bit east into the Central Interior northeast into the Yukon Flats.

FIRE WEATHER

Red Flag Conditions for thunderstorms Saturday remains over most of the central portions of the state, from McGrath through Fairbanks/Tanana Valley into Forty Mile. Saturday will likely be the heaviest lightning activity so far this fire season. Sunday storm development will likely favor the Central and Eastern Interior, with a northward extension into the Yukon Flats.

Touching on temps/rh, for the Central/Eastern Interior, high temperatures in the upper 70s to low 80s are expected to continue Sunday before a slight cooling trend to mid to upper 70s by early next week. Highs in the Western Interior will remain in the low to mid 70s through the weekend, with temperatures reaching their peak Saturday afternoon. Relative humidity will remain fairly dry this afternoon between 30 to 40%, with the exception of the Yukon Flats and Upper Koyukuk Valley seeing values near 25%. As scattered showers move in from Canada early next week, relative humidity in the Central/Eastern Interior will gradually increase while the western half of the state sees relative humidity on a slight downward trend. Winds will continue to remain fairly light and out of the west/northwest with the strongest winds expected near the Norton Sound coast, Kotzebue Sound, and Western Brooks Range.

HYDROLOGY

Water levels in rivers continue to recede. We have cancelled or expired all flood hazards and flooding is no longer expected. Rivers will return to near normal levels through the weekend.

EXTENDED FORECAST DAYS 4-7

Wednesday through next Saturday. Weak ridging is expected to remain in the Interior through the end of next week, though locations of upper level lows in the Gulf of Alaska will cause the axis to shift northeastward. The first low is already starting to move east across the Gulf, and will continue to do so through midweek. This low has access to a plume of moisture bringing an atmospheric river to Southeast Alaska and/or the Pacific Northwest, but uncertainty in its position on Wednesday/Thursday will determine how much moisture is able to make it into the Interior. If more moisture makes it into the Interior, daily convective showers have the potential for higher precipitation than what has been observed so far. Even if lower ends of expected moisture makes it into the Interior, daily thunderstorm activity is expected to continue through next weekend, primarily in the Eastern interior. As the ridge axis moves northward, temperatures are expected to rise on the Seward Peninsula, in the Northern Interior, as well as on the eastern North Slope on Wednesday and Thursday. Eventually, the upper level low moves into the Alaska Panhandle and the ridge axis moves to the south, but not before another potential low emerges over the Alaska Peninsula, and the general pattern starts to look similar to what is over Alaska today.

Schlezinger

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Red Flag Warning for AKZ929-930-934>947-951>953. Heat Advisory for AKZ833. PK...Small Craft Advisory for PKZ801. Small Craft Advisory for PKZ850.