textproduct: Fairbanks

SYNOPSIS

Overall, this week will continue to be quite a bit warmer, clearer, & drier with winds on the lighter side as general high pressure ridging will be over our entire area of responsibility. Also, some scattered showers & isolated afternoon & evening thunderstorms look to pop-up over the Western Interior, near the West Coast, over the western Brooks Range, & the western North Slope starting Tuesday afternoon/evening through late week from weak shortwaves riding northward between an area of low pressure pretty far to the west over the Siberia / Bering Sea area sending weak waves of vorticity & moisture that ride northward on the western side of the ridge that will be poised over the region & ample daytime heating all providing mechanisms for lift. High temperatures will climb into the 70s & 80s, generally the highest in the valleys & away from large bodies of water. Temperatures will continue to rise throughout the rest of the week.

KEY MESSAGES

Central and Eastern Interior...

- Things stay dry with temperatures warm steadily through the week with highs climbing through the 70s to the low 80s by Thursday, continuing into the weekend. Mostly clear skies allow low temps to fall into the 50s each night.

West Coast and Western Interior...

- High pressure results in mostly sunny skies and drier weather with high temperatures approaching 70 along the coast and mid 70s to around 80 across the Western Interior.

- Afternoon and evening shower & isolated thunderstorm chances return Tuesday afternoon and especially Wednesday before starting to go into a diminishing trend as the thunderstorm chances shift northward Thursday afternoon/evening. The higher thunderstorm chances generally shift from south to north during this time frame.

North Slope and Brooks Range...

- Highs range from near 50 over the Eastern Arctic Coast to the mid 70s near Umiat by Wednesday when warm air advects over the area & southerly downslope flow develops north of the Brooks Range.

- The period starts out with diminished chances for rain showers. Across the western areas, increased chances for scattered showers and isolated thunderstorms are possible Wednesday evening into the late work week.

SHORT TERM.../Tuesday through Thursday Night/

There is general lower pressure stretching from Siberia through the Bering Sea & to the western Gulf with 2 low centers, 1 over Siberia & another over the NW Gulf of Alaska, & a ridge of high pressure over the state of Alaska. A general clearing, warming, & drying trend takes place over the entire area as the ridge of high pressure generally dominates through the period.

Light winds are in store over the region as the pressure gradient remains rather relaxed. There really isn't a risk for any gap winds to develop through the AK Range through the entire week as there isn't enough of a southerly component to the pressure gradient & upper-level support is not there for it.

High temperatures are expected to warm to the mid-70s into the low 80s for the Interior & from the mid-60s to mid-70s for the central & western North Slope (Arctic Plains) through the short term forecast period. Areas near the coast will primarily be in the 60s. Warm air advection over the region can easily be seen with the 850mb model temperature forecast. Warm air advection over the region can easily be seen through the period with the 850mb model temperature anomaly forecast being between +3 & +7 deg C over the region, solidifying our warm temperature forecast. The eastern North Slope & near the eastern Arctic Coast will be the main exceptions as they will primarily be in the 40s & 50s for highs as they will continue to see some clouds, onshore flow, & some light showers through the short term forecast period around a weakening low pressure system meandering to their NE.

Weak shortwave troughing moves northward between the aforementioned general low pressure to the west & the building ridge of high pressure to the east starting Tuesday afternoon/evening, bringing afternoon & evening popcorn scattered showers and isolated thunderstorms from a combination of lift from ample daytime heating & upper level support over the western Interior & near the West Coast south of the Brooks Range. This will push northward into the Western Brooks Range & North Slope through Thursday evening. The support for these showers & thunderstorms is there with more enhanced support coming for Wednesday & Thursday afternoon & evening with more 500mb PVA, 700mb enhanced moisture/enhanced PW advecting over that area, enhanced model CAPE values along with low enough LI for this to be reasonably possible.

LONG RANGE.../Friday through Monday Night/

Model consensus looks to be that lower pressure will remain established over the Bering Sea region, keeping chances for showers & some isolated thunderstorms over the west. Besides that, general ridging remains setup & dominant over the rest of state, continuing to bring with it the decreased cloudiness, warm SFC temperatures, & dry conditions across our region with decent warm air advection 850mb temperature anomalies reaching around +3 to 7 deg C through the entire week, keeping high temperatures up to between the lower 70s to the low 80s south of the Brooks Range & into the lower-to-middle 70s for the inland western 2/3 of the North Slope (Arctic Plains). Eastern Arctic Coastal areas remain cooler with high temps in the 40s into the 50s through the end of the forecast period. As for the chances for scattered showers & isolated thunderstorms though Saturday for the afternoon into the evening hours, the mid-to- upper level(700-500mb) vorticity & moisture support will be there, model CAPE values look to be high enough from daytime heating, model LI values look to be low enough, & the aforementioned general low pressure trofing will continue to push shortwaves of energy around the ridge of high pressure to provide enough lift to support the continued development of these scattered showers and isolated thunderstorms. Additionally, winds will continue to remain on the lighter side through the period over the entire region as the pressure gradient remains rather relaxed through the forecast period.

FIRE WEATHER

Through the work-week, conditions will continue to warm across the entire forecast area with high temperatures in the mid-to-upper 70s, getting into the lower 80s for some areas in the western & eastern Interior. At the same time, high temperatures will warm into the 60s well into the 70s across the western North Slope(Arctic Plains), with warmth spreading eastward as we progress through the work-week, getting into the middle 60s to around 70 for only into the inland portions of the eastern third of the North Slope for Wednesday through the end of the week. Scattered popcorn showers & isolated thunderstorms from the daytime heating and energy from trofing pushing northward over the area are possible for the western Interior & westward toward the west coast for mainly mid-to-late week afternoon & evening hours. This risk will move into the western Brooks Range & western North Slope for Thursday afternoon through the evening as the trofing moves northward. Afternoon minimum RH values will steadily decrease along with the warming temperatures through the week with eastern portions of the eastern interior like 40 Mile Country, Northway, & around the ALCAN HWY (Upper Tanana Valley) dipping to around 25-30% for later in the workweek. Winds should remain on the lighter side as the gradient stays lax.

AFG WATCHES/WARNINGS/ADVISORIES

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