textproduct: Fairbanks

SYNOPSIS

A low pressure system over Bristol Bay will move into the Gulf of Alaska by Sunday. This system will continue to spread cloudy, cooler and showery conditions up into the Alaskan Range and Kuskokwim valley into Sunday. Behind this system a high pressure ridge builds over Northern Alaska with a warming and drying trend occurring through Tuesday. Isolated showers and thunderstorms will still occur Sunday and Monday over the higher terrain of the Interior.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Clouds, showers and cooler conditions will occur over the Alaskan Range Sunday and Monday. Isolated showers and thunderstorms will continue over the White Mountains and Fortymile Country.

- A warming and drying trend will occur across the Interior into Tuesday with daytime temperatures in the 70s and lower 80s. West Coast and Western Interior... - The Southwest Coast and Kuskokwim Valley will dry out by Sunday except for isolated showers and thunderstorms over the higher terrain of the Western Interior.

- Temperatures will warm into the 60s and 70s today across most of the region into Tuesday.

North Slope and Brooks Range.. - High pressure develops over Northern Alaska with a gradual warming and drying trend into Tuesday. Daytime temperatures will warm into the 50s near Utqiagvik to the 70s on the Arctic Plains.

- Occasional foggy conditions will continue along the Arctic Coast.

- Isolated thunderstorms are possible over the southern Brooks Range this evening.

FORECAST ANALYSIS AND DISCUSSION

A Bristol Bay low pressure system is moving into the Gulf of Alaska tonight. This system will rotate a series of disturbances up into the Alaskan Range and Kuskokwim valley with cloudy, cooler and showery conditions continuing into Sunday. As that low moves towards the Southeast Alaska Panhandle showers become more isolated across the Alaska Range on Monday and Tuesday with some warming.

Farther north a weak arctic trough has moved down over the Northern Interior with a stationary frontal boundary near a Huslia-Fort Yukon line. Convection will be favored along that front this evening and again on Sunday and Monday as it drifts south over the Nulato Hills, White Mountains and Fortymile. The 12Z PAFA RAOB showed 0.80" PW so storms will continue to produce decent rainfall. Shear was once again minimal. Any storms closer to the Brooks Range will have less moisture especially on Monday and Tuesday.

A high pressure ridge develops over the Arctic Plains and Brooks Range through Tuesday. The airmass will be stable under this ridge diminishing shower and lightning activity. There will be significant warming and drying throughout the Northern Alaska and the Interior under this ridge with 850mb temperatures in the 10-15C range. Will need to monitor for heat advisories especially on the Arctic Plains and Yukon Flats. The next upstream Bering Sea low pressure system begins to impact southwest Alaska on Tuesday. Still uncertainty with how strong this system will be and how far into the Interior the moisture will get. Both the 12Z EC and Canadian are faster than the 12Z GFS in moving this system into the Gulf of Alaska by Wednesday. The EC/Canadian are the preferred weaker solution with the Arctic ridge of high pressure remaining in place over the Interior. That should favor less shower and lightning activity and more hot and dry conditions.

FIRE WEATHER

Over the next several days, a high-pressure system transiting the northern parts of the state will begin to make itself known, helping to expand the footprint of hot and dry over much of the interior and into the Arctic Plains (focused from Sagwon west to Umiat). Simply put, temperatures will continue to trend upwards into the 75F to 85F range and min RH back down to 25 to 35 percent. One exception for min RH will likely be the southwestern portion of our area from McGrath toward the YK Delta. Isolated thunderstorm activity Sunday will largely be felt across the higher terrain of the interior stretching from the Nulato Hills into the White Mountains and Fortymile, expanding and shifting further west and north on Monday.

We are still tracking a low undercutting the state through the weekend, which will serve as the mechanism for inverted troughs and moisture transport into the eastern portion of the state mid-week. Ensemble systems continue to highlight PWAT values near 1 inch, well into the 90 th percentile for this time of year. Ridge breakdown sometime late next week, combined with inverted troughs and excellent moisture, will bring vigorous wet thunderstorm activity back to the state.

EXTENDED FORECAST DAYS 4-7

Tuesday through Friday Moving into the extended time frame, a low will move into the southeastern Bering Sea and from there into the Gulf by Wednesday. As this occurs, a second low in the eastern Gulf of Alaska will draw robust moisture into the Interior. While there is uncertainty on any exact rainfall totals, significant rainfall with showers and thunderstorms will be possible in the southern Interior from Wednesday through the end of the week, including in the Alaska Range. Many areas could see between a quarter and a half inch, with higher totals possible locally. Heavy rain will also be possible in the Brooks Range but is less certain. Most of the Interior and much of the North Slope will see temperatures in the 70s or 80s, with pronounced ridging extending from Canada into northeastern Alaska.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...None.