textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

- A Wind Advisory remains in effect for Anchorage and the Hillside through 10AM Tuesday. Wind gusts 40 to 50 mph are expected for west/south Anchorage, while the Seward Highway near the Turnagain Arm and the Hillside will see gusts up to 60 mph.

- Flood Watch remains in effect for the eastern Kenai Peninsula from Monday night through Thursday morning, due to heavy rain.

- Flood Watch remains in effect for Susitna and lower Matanuska Valleys from Tuesday morning through Friday morning, due to heavy rain.

Discussion:

Light rain has begun to spread into the region this morning with more widespread rain filling in over the Susitna Valley. This is quicker that most of the hi-res and longer range models have for timing. This means that portions of the western Kenai up through the Mat Valley may see intermittent light rain beginning by mid-morning. Temperatures have fallen into the 50s for most locations across Southcentral this morning and with abundant cloud cover throughout the day, temperatures won't warm more that a few days today and tomorrow. The exception will be the Copper Basin where temperatures should warm into the mid to upper 60s in the river valley.

Even with rainfall moving in more quickly, the forecast remains on track with a cool and wet forecast for western Southcentral and the coastal zones for the upcoming week. Moderate to heavy rainfall is still on track for portions of the Susitna Valley and Eastern Kenai Peninsula where Flood Watches remain in effect. Satellite imagery shows a very moist plume sub-tropical moisture streaming north into western Alaska this morning. This plume will move eastwards towards Southcentral by late tonight, and while it will lose some of its punch...precipitable water values will still be well above the daily average, and may actually near the daily max per the PANC sounding climatology.

A strengthening coastal ridge has resulted in gusty winds developing overnight along the Turnagain Arm and other known gap flow spots along the Chugach Mountains. West Anchorage and the Palmer area have seen gusts of 30 to 35 mph this morning with the Hillside gradually increasing to around 30 to 40 mph. As this gradient continues to tighten today, winds over the west/south Anchorage and the Hillside will see stronger winds develop later today with the strongest winds expected this afternoon into this evening. The Knik winds will also remain gusty with gusts up to 40 mph. Lastly, the Copper Basin will see southerly winds increase this morning with the strengthening coastal ridge and could see some spillover of light rain into the far southern edge of the basin.

- PP

AVIATION

PANC...Strong southeasterly Turnagain Arm winds will persist through the TAF period, with periodic gusts to 35 kts. While VFR conditions (with ceilings greater than 5000 ft) will likely continue through the morning, rain showers and lower ceilings are expected to fill in by mid-to- late afternoon. However, the exact timing of this remains uncertain given the strong downslope flow mixing in drier air, which could delay the onset of rain and lower ceilings. MVFR conditions are possible through the evening and into tomorrow morning, with potential dips into IFR during stronger showers.