Marine Weather and Tide Forecast for Whittier, AK

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3: Today through Tuesday)...

Satellite imagery this afternoon depicts the low pressure which brought today's rainfall departing north to the Interior while the next shortwave and associated surface low passes north of the Pribilof Islands and closes in on the Southwest coast. This brings another round of light rainfall overspreading Southwest Alaska this afternoon through this evening. The wet and active pattern looks to continue through the forecast period as the longwave trough remains anchored roughly over the eastern Bering Sea, with several robust shortwaves and spokes of energy rotating around the base of the trough.

By Sunday morning, rainfall across Southwest Alaska becomes increasingly showery as the next weak low dives south across the Bering. Models are in good agreement for this system to be rather short-lived and dissipating as it reaches the Pribilofs Islands by Sunday afternoon. Meanwhile, the ridge in the Pacific becomes more amplified as the overall flow becomes heavily influenced by the next storm lifting out of the North Pacific and towards Adak and Atka by Monday morning. This low crosses the Aleutians and moves across the southeastern Bering Sea through Tuesday morning, bringing a moisture-rich fetch of warm air from the Pacific and more rainfall across the Aleutian Chain and to Southwest through Tuesday. Of more interest with this system is the renewed possibility of marine lightning and isolated thunderstorms beginning Monday morning for the coastal zones south of Adak/Atka, eventually spreading east to the eastern Aleutians and Alaska Peninsula through Tuesday morning. Confidence on marine lightning potential remains fairly low, so stay tuned to forecast updates as models continue to come into better agreement and confidence increases.

.LONG TERM FORECAST (Days 4 through 7: Wednesday through Saturday)...

Just in case you were hoping for a major pattern change... not yet. An active and relatively cool weather pattern remains in place across Alaska through the end of the week as a broad longwave through persists over the Mainland. Embedded shortwaves rotating through the flow will continue to bring periods of rain to much of Southwest and Southcentral Alaska through the longer term period, with locally moderate rainfall possible where stronger disturbances track inland. Temperatures are expected to remain near to slightly below seasonal normals, with plenty of cloud cover keeping conditions feeling cool. Inland winds generally remain light, while breezier conditions persist along the Gulf Coast and adjacent marine waters.

Farther west, ridging over the Bering Sea gradually shifts east as a series of North Pacific lows approach. This will allow increasing clouds, rain, and strengthening winds to spread eastward across the Aleutians and Bering before eventually expanding into western portions of the Mainland. The overall pattern remains progressive, with little opportunity for prolonged drying.

Forecast confidence decreases somewhat late in the week as guidance continues to differ on the timing and track of additional shortwaves and surface lows. Despite these differences, confidence remains high in the overall unsettled pattern. Another North Pacific low is excepted to move into the Gulf by late week, maintaining widespread cloud cover and periods of rain across Southern Alaska into Saturday, while additional showers linger father inland. Gusty coastal winds will accompany the stronger systems, particularly along the Gulf Coast and portions of the Alaska Peninsula. Temperatures are expected to remain on the cool side through the weekend as persistent cloud cover and recurring rainfall continue across much of the state.

LM




AVIATION

PANC...VFR conditions will persist through much of the TAF period despite persistent cloud cover associated with an approaching front. Southwesterly winds turn southeasterly this evening gusting to 20 kts. The approaching front brings isolated rain showers to the terminal this evening though more steady, widespread showers arrive late tomorrow morning continuing through the day. MVFR conditions are likely during this time as ceilings to drop to around 5000 feet.