Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/30/17


AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
828 PM PDT Mon May 29 2017 .SYNOPSIS... A trough of low pressure aloft will deepen across California mid week, before gradually shifting east of the region late in the week. This pattern will support a cooling trend with overnight to morning low clouds and patchy drizzle becoming more widespread through mid week, with a gradual warming trend late in the week. && .SHORT TERM...(TONIGHT-THU) Satellite imagery showing low clouds and fog moving into many of the coastal areas this evening. Acars sounding showing marine layer depth around 1500 feet over the LA basin this evening. A weak upper level trough of low pressure combined with strengthening onshore flow and an eddy circulation will help to deepen the marine layer to around 2000 feet by tomorrow morning. As a result, looking for low clouds and fog to fill into most coastal/valley areas overnight into Tuesday morning, lingering near some of the beaches in the afternoon. High temperatures on Tuesday are expected to be slightly cooler across most areas. The Antelope Valley will see some gusty onshore winds with very warm temperatures above 90 degrees which will translate into elevated fire danger concerns. The foothills of the Antelope Valley could see some gusts as high as 45 mph by late afternoon and evening on Tuesday. *** From previous discussion *** At the beaches, a `May Gray` pattern will likely conclude the month, possibly turning to `June Gloom` to begin the month of June. Stratus clouds will struggle to clear at the beaches each over the next couple of days and the beaches will likely remain socked in. As the trough starts to move east on Tuesday, another broader trough circulation will move in. Instability with the trough will bring mainly partly to mostly cloudy skies across the area for Tuesday night through Thursday, along with the possibility of night through morning drizzle. PoPs have been tweaked a little to account for measurable drizzle. A slight chance of showers remains in the forecast for the interior portions of the area as well as the mountains. .LONG TERM...(FRI-MON) Ridging aloft over the Pacific Ocean builds in for Friday and Saturday, then another trough will approach the area for next weekend. Heights do climb a bit, so some warming was introduced; however, onshore flow should remain and inhibit the air mass getting too warm for this time of year. Temperatures looks to remain near normal for the end of the week and into next weekend. && .AVIATION...29/2345Z... At 2345Z, the marine inversion at KLAX was based at 1400 feet. The top of the inversion was 4400 feet with a temperature of 22 degrees Celsius. For tonight, high confidence in return of stratus/fog to all coastal/valley sites, but only moderate confidence in timing and flight category. Based on satellite trends, moved up timing of cigs to coastal areas between 00z-04z and valleys between 06z- 08z. Chance of cigs lingering into afternoon hours on Tuesday at KOXR, KCMA, KLAX, and KSMO. KLAX...For tonight, high confidence in return of stratus, but moderate confidence in timing and flight category (40% chance CIGs come in at IFR levels). KBUR...For tonight, high confidence in return of stratus, but moderate confidence in timing (+/- 2 hours of current 08Z forecast). && .MARINE...29/100 PM... For the Outer Waters, high confidence in current forecast. Small Craft Advisory (SCA) level winds will continue through Saturday. Each afternoon/evening, there will be a 30% chance of Gale force gusts developing. For the Inner Waters, moderate to high confidence in current forecast. For the waters north of Point Sal, SCA level winds are expected each afternoon/evening today through Friday then drop below SCA levels on Saturday. For the waters south of Point Conception, conditions are generally expected to remain below SCA levels through Saturday. However, there is a 30% chance of SCA level winds across the western half of the Santa Barbara Channel during the afternoon/evening hours on Wednesday and Thursday. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 9 AM PDT Wednesday for zones 645-670-673-676. (See LAXMWWLOX). && .HAZARD POTENTIAL OUTLOOK...(THU-MON) No significant hazards expected. && $$ PUBLIC...Gomberg/Hall AVIATION...Gomberg MARINE...Thompson SYNOPSIS...Munroe weather.gov/losangeles