Scientific Forecaster Discussion
000 FXAK69 PAFG 272051 AFDAFG Northern Alaska Forecast Discussion National Weather Service Fairbanks AK 1251 PM AKDT Tue Jun 27 2017 .DISCUSSION... The 12z model suite initialized well against the 12z surface analysis and verified well against the 18z surface analysis. Model spread from run to run as well as from different model families remains minimal in the short range and is very reasonable through the end of the week with good agreement on longwave pattern and only minor differences in timing with a series of shortwaves moving north into the eastern Bering Sea, the west coast as well as the western interior through the rest of the week. Arctic coast will continue to be under the influence of high pressure centered near Banks Island with easterly flow bringing rounds of low clouds and fog with some diurnal influence with some mild improvement in ceilings and visibility during the afternoons over much of the coastal areas especially to the east of Barrow today through Friday. A weak low moving north out of the western interior late Friday and Saturday will bring increased chances for rain and rain showers over the north slope especially to the west of Barrow through Saturday. Over the west coast and western interior a weak low moving north out of the north pacific will move over Bristol Bay tonight and will continue to move north along the coast and weaken to a trough. As the trough continues to move north rain showers will increase today with periods of rain developing this evening in the lower YK delta and late tonight over the Seward Peninsula. A series of weak waves will continue to move north over the west coast bringing wetting rains and limiting fire weather concerns through the end of the week. Over the central and eastern interior weak ridging aloft combined with weak down slope flow over the Alaska Range will continue to dry out the interior. Minimum relative humidities will drop from the 30s today to the 20s Wednesday and Thursday before increasing again on Friday into the 30s as moisture moving around a low in the Gulf Alaska pushes in from the southeast Friday. Temperatures will meet Red Flag criteria over a few locations in the central and eastern interior this evening and again on Thursday. Minimum relative humidity levels will likely meet Red Flag Criteria over much of the central and eastern interior tomorrow however wind criteria for Red Flag conditions are not expected to be met either today or Wednesday. Thunderstorm activity will be along and north of the thermal trough from near Chicken to Fairbanks to Bettles and Ambler today with a shift north along the Brooks Range tomorrow. The thermal trough will form again along a Chicken to Bettles to Ambler line on Friday. Coastal Hazard Potential Days 3 and 4...None. && .FIRE WEATHER...Gap winds through Alaska Range passes this evening and over night will meet wind advisory criteria in zone 226 however wind advisory criteria is not expected to be met in zones 225 or 223. Wind criteria for Red Flag conditions will likely be met this evening and over night in zone 226 however relative humidity criteria is not expected to be reached in zone 226 this evening and over night. Tomorrow minimum relative humidity values will drop into the low 30s over much of the interior and temperature criteria may be reached at a few locations however wind criteria is not expected to be reached. Min relative humidities will continue to drop over the central and eastern interior into the low to mid 20s this week while relative humidities are expected to remain above 40 percent over the west coast and western interior with several periods of rain and showers moving over the area. Thunderstorm activity will be along and north of a line from Chicken to Fairbanks to Bettles and Ambler today with a slight shift north to along the Brooks Range tomorrow. && .HYDROLOGY...The Fortymile and Tanana Rivers will continue to run high today and Wednesday with heavy rain event last weekend. River crests are expected to remain at or below bankfull stage. Continue to monitor. && .AFG WATCHES/WARNINGS/ADVISORIES... Wind Advisory for AKZ226. Small Craft Advisory for PKZ230. Brisk Wind Advisory for PKZ235-PKZ240-PKZ245.