textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

* A Gulf low will affect Southcentral Alaska today into Tuesday.

* Multiple Winter Weather Advisories remain in place across Southcentral this afternoon through Tuesday afternoon.

* Blizzard Warning remains in place for Thompson Pass through noon Tuesday. * A Wind Advisory is in effect for Whittier, Portage Valley, and East Turnagain Arm through Tuesday morning.

A deep Gulf low has moved north into the northern Gulf, spreading precipitation across the SouthCentral coastline and lowering ceilings further inland. As the atmospheric column moistens, precipitation will spread further inland under a northeast to easterly wind, though amounts will remain relatively light versus the higher amounts expected over the coastal mountains (about 2000 feet or higher), where precipitation is set to remain snow through the event. Elsewhere, snow will transition to a freezing rain mix, and eventually all rain as surface temperatures warm under a southerly push Tuesday morning. This period will coincide with the development of a gusty Turnagain Arm wind that will extend through the mid to late morning Tuesday. A number of winter weather and wind products have been issued for this event, so please see these products for more details.

By late Tuesday afternoon and evening, the Gulf low will weaken substantially, though the parent low will remain over the Gulf, with additional areas of enhanced winds and precipitation rotating around the broader circulation through Thursday. Heaviest precipitation will primarily be across the coast.

-AB

AVIATION

PANC....A leading front from a deep Gulf low will arrive this afternoon, bringing a brief period of flurries or light snow in the 00z-03z timeframe. The limiting factor for snowfall will be dry low level air. with gusty northerly winds helping maintain the dry air. Bottom line, ceilings and vis will likely remain VFR, with worst case scenario a very brief period (less than an hour of MVFR conditions). The front will quickly shift westward early this evening, causing ceilings to rise.

Precipitation will re-develop overnight, most likely after 09Z. Increasing easterly flow aloft will lead to above freezing air riding over top of the sub-freezing surface temperatures. Expect a transition from light snow to freezing rain to rain. For the terminal, the transition from snow to rain looks pretty quick, so expect little or no snow and ice accumulation. By 12Z expect temperatures to rise to 34 degrees or so with periods of rain continuing through the morning hours. The strengthening easterly flow will ensure ceilings remain relatively high - likely in the low end VFR category.

Northerly winds will die down overnight, becoming light and variable. The remnants of the upper trough will pass overhead and inland Tuesday afternoon, which could be enough to bend the southeasterly Turnagain winds into the terminal. However, a weak remnant surface low will move to southern Cook Inlet, favoring a light northerly wind. Confidence is low (30-40%) on whether the Turnagain winds bend into the terminal.

-SEB