textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

*** A Winter Weather Advisory has been issued for Southwest Kenai Peninsula including Clam Gulch, Anchor Point, Ninilchik and Homer from 6 pm this evening to 12pm Thursday.

*** A Winter Weather Advisory has been issued for Skilak Lake- Including the cities of Cooper Landing and Skilak Lake from 9 pm this evening to 3 am Friday.

*** A Winter Weather Advisory has been issued for the Interior Kenai Peninsula-Including the cities of Moose Pass, Hope, and Summit Lake from 9pm this evening through 3 am Friday.

*** A Winter Weather Advisory has been issued for Turnagain Pass from 9 pm this evening through 3 am Friday.

A series of fronts move through the Gulf of Alaska the next few days bringing precipitation and warmer temperatures to Southcentral. The Kenai Peninsula will be most impacted by these fronts.

This evening into tomorrow morning, a front associated with a North Pacific low south of the Central Aleutians crosses the Gulf of Alaska bringing snow, rain and pockets of freezing rain to the Kenai Peninsula this evening into tomorrow evening. Easterly winds into the eastern coast of the peninsula will have a difficult time warming most interior locations through sunrise tomorrow. Therefore, higher elevations on the Seward Highway will remain cold enough through the overnight hours resulting in a heavy, wet snow to fall as low as 1,000 feet this evening and overnight. The snow level rises to 1500 feet late tomorrow morning. This rise in snow level corresponds with a rise in surface temperatures. The precipitation changes to periods of a rain/snow mix tomorrow afternoon and evening for these areas as well as across the Kenai Peninsula. Snowfall amounts will vary greatly depending on the amount of warm air flows into the area. Therefore, there could be areas of rain in places along the highway with other areas experiencing moderate to heavy snowfall. Snowfall totals range from 8 to 16 inches in Turnagain Pass to 5 to 10 inches along the Seward highway from Hope to Primrose.

It is worth noting that warmer air could filter into the southwest part of the Kenai Peninsula resulting in rain falling on still frozen ground. This would create hazardous conditions on the Sterling Highway from Sterling to Cooper Landing. Temperatures rise above freezing late tomorrow morning shortly after the arrival of southeasterly winds. Elsewhere, on the lee side of the Chugach Mountains, easterly winds will allow for efficient downsloping to occur in the Anchorage Bowl with this storm; limiting precipitation amounts.

-Johnston

LONG TERM FORECAST (Days 4 through 7/Sunday through Wednesday)

The long term forecast starts off with continued warm air being advected northwards from the North Pacific due to a low south of the Aleutians. The North Pacific low will also allow for widespread precipitation to affect the Aleutian Islands, the Alaska Peninsula, and the Southcentral Coast including Kodiak Island on Sunday. The heaviest precipitation is expected in Southcentral due to a fetch of moisture from the south. Also, the Western Aleutians will see northerly flow and gale force winds from the low. The Kuskokwim Delta and Bristol Bay will not see large impacts with this low and may see light to moderate precipitation at times with northeasterly winds. The Southcentral Coast may also see a period of gale force winds as a front moves into the Northern Gulf.

Monday sees chances for precipitation decrease as the low weakens and high pressure moves into the Gulf. However, a second North Pacific low moves up towards the Bering and brings another round of precipitation and gusty winds to the Aleutians starting Monday evening and lasting through Wednesday. This time, moderate to heavy precipitation may make it to the Bristol Bay and the Kuskokwim Delta. Winds are more uncertain, but gusty northerly winds may affect the coastal Southwest Mainland as well. These northerly winds would also allow for sustained cold air advection, which would cool temperatures considerably in Southwest Alaska. Meanwhile, Southcentral will have some potential for precipitation by Tuesday as the low slowly moves eastward. Uncertainty is higher for Southcentral, however.

-JAR

AVIATION

PANC...Northerly winds increase today at the terminal but generally remain below 10 knots and persist through Thursday. Ceilings are likely to remain above 5000 ft for the duration of the TAF period. There is potential for increasing wind shear beginning overnight as southeasterly winds at 2000 ft or higher increase to around 40 knots. This low-level wind shear potential lasts through around noon Thursday. Southeasterly Turnagain Arm winds may also move over the terminal by Thursday evening, lingering for several hours before becoming northerly.

A front lifting across the terminal Thursday into Friday, will introduce increasing chances of overrunning snow showers as early as Thursday. This leads to increasing potential for ceilings and visibility to drop to MVFR in passing showers, though the probability is still considered low at this time.

TM/CQ