Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/25/22


Southeast Alaska Forecast Discussion...CORRECTED
National Weather Service Juneau AK
352 PM AKDT Sun Apr 24 2022 .SHORT TERM.../Through Monday night/...A weakening low south of the Gulf of Alaska will continue to rotate showers north over the Panhandle through this short term forecast period. The low is already weak enough and far enough to the south that winds will not be impactful through the period. Small craft advisories are limited to the coastal marine zones for residual seas, which will subside to less than 8 feet overnight. Some patchy fog may form but is not expected to be impactful either. Cloud cover will persist with the shower activity, limited both daytime heating and overnight cooling. Boring short term forecast. .LONG TERM...No change in thinking for the extended period as ensemble means continue to struggle finding common ground on developing surface features. A lingering low pressure will move south of Haida Gwaii Tuesday keeping showers across the southern panhandle. Also, a broad area of low pressure develops over BC Tuesday. Operational models want to bring an organized band of precip over the Coast Mountains Tuesday afternoon through Thursday. It is a common understanding that these models do not resolve the topography well along these mountains and will typically over do the amount of precip that moves over the panhandle. This is where the forecast challenge lies. Decided to bring scattered to numerous showers over the panhandle with the associated easterly wave with the caveat that there will be extended periods of dry weather. As expected, as the area of low pressure develops over BC, mostly cloudy skies will remain over the panhandle through mid week. Day time temperatures were cooled through the period and over night lows were slightly raised with the increased cloud cover. && .AVIATION...Broken to overcast conditions will continue over Southeast Alaska through the next 24 hours as bands of showers rotate north-northwest from a low south of the Gulf. CIGS remaining between 1K and 3K with occasional excursions into IFR. Marginal reductions to visibility will be mostly a result of shower activity but genuine fog is possible late tonight in some locations. The low level jet has relaxed and no LLWS is expected. Any turbulence will be light. The freezing level remains low - between 2500ft and 3500ft based on MDCRS data - and there have been several PIREPS received today reporting light rime icing. Little change is expected tomorrow. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...None. MARINE...Small Craft Advisory for PKZ041>043-051-052. && $$ Fritsch/CC Visit us at http://www.weather.gov/Juneau