Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/24/21

Area Forecast Discussion
National Weather Service Boston/Norton MA
954 PM EST Thu Dec 23 2021 .SYNOPSIS... High pressure over the East Coast will diminish as it moves offshore Friday. Weak low pressure breaks through the weakening high late tonight and Friday. Another storm system brings the threat for rain and some wintry precipitation to the region Christmas Day, but uncertainty on details remain. After a brief respite, more unsettled weather is possible for the first half of next week but nothing very impactful is currently expected. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 955 PM update... Forecast mostly on track. Only change was to lower pops a bit across eastern MA as best forcing and moisture will remain across western New Eng through the overnight period. RAP does show some modest lift into the snow growth region across western and central MA into northern CT where a period of steadier light snow is likely. Previous Discussion... Zonal flow across the region with a shortwave trough approaching through the Great Lakes. Falling surface pressures noted over the Great Lakes and Ohio Valley, trending ESE. Sufficient cloud- level moisture moves in around 06Z to support lowering clouds. Blowoff from this cloud area will bring increasing high-level sky cover. Main question with this system is the amount of lift generated and resulting precipitation. PW remains low, at 0.2 to 0.3 inches. A 30- kt jet at 850-mb moves along and ahead of the shortwave, riding over the colder air at the surface. Expect this to mechanically force some lift over Srn New England, which may generate a period of precipitation late tonight and Friday morning. Based on the light moisture and weak lift, amounts should be 1 inch or less most places and with 1 to 1.5 inches in hilly parts of the Worcester/Central Hills and Berkshire East Slopes. Cold surface temps this evening and early tonight from an early period of cooling. Lowered temps a few degrees below guidance, with a general range of mid teens to mid 20s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Overview... Shortwave trough moves off to the east. Shortwave ridge moves overhead Friday. Next shortwave trough approaches Friday night. Details... Light snow that begins late tonight tapers off on Friday. A shortwave ridge moves overhead and may provide enough subsidence for brief partial clearing Friday afternoon. Will show light snow in the morning, tapering off by midday. Afternoon highs in the 30s. A 50-kt jet moves up the Ohio Valley. Will it move east enough to generate lift over Srn New England? GFS and ECMWF hold these winds to the southwest. Meanwhile, 130-kt upper jet moves over the Northeast and should generate enough lift for returning clouds Friday night. Based on the two jets and the potential for lift...will forecast chance pops after midnight. Initial precip occurs during the cold part of the night, so will expect snow or sleet at onset. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Highlights * Wintry mix Christmas morning to transition to a rainy Christmas day * Unsettled weather early next week with a chance for rain/snow Monday through Wednesday. Saturday and Sunday A surface low-pressure system approaching from the Midwest Christmas morning will lift a surface-warm front through southern New England on Christmas Day. This will provide sufficient forcing for precipitation on Christmas morning. Unfortunately for those hoping for snow on Christmas morning the outlook does not look good. Temperatures at 850 hPa and 925 hPa are expected to be above freezing as the warm front lifts through the region. With sub- freezing temperatures in the low-levels this would be supportive of either sleet or freezing rain depending on the depth of the melting layer aloft. Right now confidence is low in that department with the NAM supporting a more shallow melting layer/sleet temperature profile and the global models supporting a deeper melting layer/freezing rain temperatures profile. Regardless of what kind of frozen precipitation we see early in the day, surface temps are expected to rise above freezing by late morning. This will result in a changeover to rain for most of the region. Expect showers to continue into Saturday night as the surface low-pressure system moves over southern New England. We could see another round of frozen precipitation late Saturday night as temperatures fall back below freezing. Lingering showers taper of Sunday morning as northwest flow behind the low-pressure systems ushers cooler drier air into southern New England. This will set the stage for clearing skies and another cold/blustery day with gusty northwest winds and high temperatures in the upper 30s to low 40s. Monday through Wednesday Upper-level ridge positions itself over the eastern US next week. This will limit any significant precipitation for southern New England. However, models are hinting at a few pulses of short-wave energy riding along the ridge that may support slight chance rain/snow showers early next week. As this ridge breaks down during the middle of next week, we may have the potential to see more substantial winter precipitation in the Wednesday/Thursday time frame as a low-pressure system develops over the Midwest and approaches the Northeast. Confidence is very low at this point, so won`t dive into details at this time. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight... VFR through midnight, then bases lower overnight. A period of MVFR cigs late at night with any precipitation...except possibly IFR at ORH. Expect light snow, except some rain along the South Coast. Friday... MVFR in the morning in light snow, then improving to VFR during the afternoon. Light wind. Friday night... VFR most of the night, but may trend toward MVFR cigs toward sunrise. Chance of snow or a snow/sleet mix late at night. KBOS Terminal...High confidence. KBDL Terminal... High confidence. Outlook /Saturday through Tuesday/... Christmas Day: Mainly VFR, with areas IFR possible. Chance RA, chance SN, slight chance FZRA. Saturday Night: MVFR/IFR conditions possible. Breezy. Chance RA, chance FZRA. Sunday: Mainly VFR, with local MVFR possible. Windy with local gusts up to 30 kt. Slight chance RA, slight chance FZRA. Sunday Night: VFR. Breezy. Monday: Mainly VFR, with local IFR possible. Breezy. Slight chance SN. Monday Night: Mainly VFR, with areas IFR possible. Slight chance RA, slight chance SN. Tuesday: MVFR/IFR conditions possible. Chance RA, slight chance SN. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight... Northwest winds diminishing through the night. Winds gusting 20-25 kt in the evening, but 15 kt or less after midnight. Seas 5 feet on the outer waters early tonight, but 3 feet or less by morning. Continue Small Craft Advisory on the outer waters through early tonight. Friday... Weak weather system moves across Srn New England from early morning through midday. This will bring a period of light rain to the waters, with light snow along the coast. Light wind, seas 1 to 3 feet. Friday night... Quiet weather to start the night, with light winds and 1 to 3 foot seas. Clouds increase overnight with a chance of rain toward morning. Outlook /Saturday through Tuesday/... Christmas Day: Winds less than 25 kt. Chance of rain, slight chance of freezing rain. Saturday Night: Winds less than 25 kt. Local rough seas. Rain likely. Sunday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 13 ft. Chance of rain showers, slight chance of rain. Sunday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Monday: Winds less than 25 kt. Local rough seas. Slight chance of rain. Monday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain. Local visibility 1 to 3 nm. Tuesday: Winds less than 25 kt. Slight chance of rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 1 AM EST Friday for ANZ250-254. Small Craft Advisory until 10 PM EST this evening for ANZ255- 256. && $$ SYNOPSIS...WTB/RM NEAR TERM...WTB/KJC SHORT TERM...WTB LONG TERM...RM AVIATION...WTB/RM MARINE...WTB/RM
Area Forecast Discussion
National Weather Service Cheyenne WY
414 PM MST Thu Dec 23 2021 .SHORT TERM...(Today through Saturday night) Issued at 330 PM MST Thu Dec 23 2021 Forecast challenges deal with strong winds today...followed by snow and impacts this evening through Friday. Currently...Cold front moving into the west coast with cloud band from central Montana through Nevada...through central California. A piece of energy moving through southern Carbon County this morning and afternoon has brought some light snow to Dixon and well as .5 to .6 inches of SWE to the Sierra Madre so far. Looks like a good start to our warnings out there. Gradients begin to ease this evening. GFS 700mb winds decrease from 60kts...down to 35-40kts by 06Z. Increasing cloud coverage and lift expected to bring winds down even more. So likely will be able to cancel wind warnings early. There was some concern with possible blizzard warnings for WYZ 109 and 110. But since there is only a small window of winds and a decrease in coverage of snow this evening during the period of strongest winds...decided not to upgrade the winter storm warnings. Will let the evening shift take another look this evening to see if Blizzard Warnings are needed. This area of heavier precip hangs around the mountains through 00Z Saturday. Latest HRRR guidance showing precip shifting south with this first initial wave this could see snow decreasing in coverage across Carbon County for a time. It will be short lived as next piece of energy moves into Carbon by 05Z or so. Expect to see an increase in coverage and intensity after that time. All guidance showing near .5 inch 6 hour qpf over the Snowy and Sierra Madre Ranges by 12Z. Strong upper shortwave approaches from the west Friday evening with surface front sagging south. Heavy snow continues over the Snowy and Sierra Madre Ranges through Saturday morning. Storm total snow amounts we have been forecasting still look on track with near 3 feet in the Sierra Madres and 2 feet in the Snowys. .LONG TERM...(Sunday through Thursday) Issued at 330 PM MST Thu Dec 23 2021 The long term forecast will be comprised of an active weather pattern and below to much below average temperatures. Multiple cold fronts will approach and sweep across the region for the extended forecast as anomalous height falls at the H5 level result in longwave troughing across the majority of the western CONUS, and multiple shortwaves will eject out of the 4 Corners region toward our cwa almost daily through the middle of next week. The coldest air of the season is likely to impact southeast WY and the Nebraska Panhandle by the middle of next week should the guidance continue its signal of colder weather. For Sunday, concerns will remain elevated as mountain waves are anticipated per the latest guidance. Craig to Casper gradients tighten as the day continues onward, primarily between 18Z Sunday and 6Z Monday. Wind gusts up to 50-60mph will be possible in the wind prone corridors as west winds aloft at 700mb increase to 50-65 knots. Guidance is also signaling the winds potentially spreading into the northern Nebraska Panhandle if mixing down to the surface ensues. Additionally, a shortwave disturbance will cause persistent snow showers to occur over the mountain terrain, with orographic enhancement potentially leading to accumulations near headline criteria. A cold front will sweep through the area Sunday night into Monday. Temperatures will likely hover around freezing east of the Laramie Range for Monday. Looking aloft, the upper level trough axis will propagate toward the area Monday into Tuesday, originating from the west coast. Wind gusts look to remain breezy for the ARL and BRX wind prone corridors as gradients look modest, but not alarming at this time. The major event to pay attention to is the arctic air that will be pushing southward from Canada Tuesday night into Wednesday. 700mb temperatures between -25C to -30C over Montana will sag south by Wednesday morning. Trended downward with the overnight low for several areas Wednesday, especially with the anticipated snowfall across the area west of the Laramie Range. If trends continue with guidance, wouldn`t be surprised to see areas as far south as Cheyenne with an overnight low below zero early Wednesday. The cold air will likely stick around for a majority of the week as additional intrusions of CAA via shortwave disturbances keeps temperatures at or below freezing for most of the cwa. This lines up well with the CPC 8-14 day outlook where below normal temperatures and above normal precipitation chances are favored for the next two weeks. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 415 PM MST Thu Dec 23 2021 Upper level ridging has continued tracking eastward across the Great Plains as a cold frontal boundary digs southeastward through the CWA. Latest HiRes guidance indicates precipitation shifting southward from the first initial wave this evening and snow development west of the Laramie Range. As a result, conditions will deteriorate west of the Laramie Range with LIFR possible for reduced visibilities as the elevated wind speeds increase the chances for blowing snow. Main challenges will remain with how strong the winds will become through tomorrow, and the most eastern extent of any precipitation. Left the terminals with the greatest uncertainty as VCSH with the possibility of upgrading to snow/rain and visibility reductions required in later TAF issuances. && .FIRE WEATHER... Issued at 250 AM MST Thu Dec 23 2021 Fire weather concerns will remain low west of the Laramie Range Thursday through the weekend due to an incoming winter storm that is expected to drop quite a lot of snow over the mountains. The lower elevations will also likely see some snow west of the Laramie Range. Conditions to the east of the Laramie Range will remain pretty dry, but not as dry as they have been this past week. Overnight humidity recoveries also look to be much better than they were. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Winter Storm Warning until 11 AM MST Saturday for WYZ112-114. Winter Storm Warning until 11 AM MST Friday for WYZ111-113. High Wind Warning until 2 AM MST Friday for WYZ101-104>107-109- 110. Winter Storm Warning until 5 PM MST Friday for WYZ109-110. NE...None. && $$ SHORT TERM...GCC LONG TERM...BW AVIATION...MD FIRE.......SF
Area Forecast Discussion
National Weather Service Des Moines IA
921 PM CST Thu Dec 23 2021 .UPDATE... Issued at 921 PM CST Thu Dec 23 2021 Some increasing concern of fog potential across the region overnight into Friday morning as low level moisture streams into region. Have added to forecast. The fog is more likely to develop after 3 to 4 am in the south and then lift northeast out of the area by around noon. Some light drizzle may form as well by 8 to 9 am. Visibility already decreasing over eastern KS and central Missouri. Will pass along to mid shift for potential weather statement or possible early morning headline if fog becomes widespread. /rev && .DISCUSSION.../Tonight through Thursday/ Issued at 327 PM CST Thu Dec 23 2021 Primary messaging highlights: * Rear record or record warmth in spots tomorrow * Patchy fog possible tonight and again tomorrow night * Three light precip windows into next week. Minor travel impacts possible at times, mainly north. Mid and high level moisture continues to stream into the MO Valley in the fast zonal flow with hints of other upcoming weather still well upstream off the Pacific NW and CA coast, and moving through WA. Our initial sensible weather will be increasing clouds and potentially fog later tonight. The 19z surface analysis shows 40+ dewpoints across eastern KS and MO, and this low level moisture is expected to stream northward to some degree in response to the broad low level cyclonic flow associated with the aforementioned WA PV anomaly. This will likely result in stratus development and at least patchy fog as the moisture moves over the cool ground. Do not expect much drizzle with only the typically overzealous NAM and NAMNest suggesting any QPF. A repeat of this morning`s frost is not expected either with cloudy skies overnight keeping road temps above freezing. Temperatures are expected to warm further into tomorrow with record or near record temperatures expected in some locations. Des Moines isn`t in play however due to its longer period of record (69F/1889), an event that other station records wouldn`t capture. Precip looks to return to the forecast early Christmas morning. The system in the base of the western trough, now off the CA coast, should cross the Rockies into the Plains late tomorrow enhancing the frontal boundary to our south, which will pass and end our recent warm spell. Fairly deep thermodynamic and kinematic support will combine to produce deeper saturation leading to a period of non-trivial precip with amounts of a few tenths possible south. Some light snow is possible on the northern fringe, but much of this should be a cold rain. After a brief break Christmas and Christmas Night, another fast moving wave will take a similar track crossing the Rockies into the Plains late Sunday. The forcing with this system will be stronger, but with a bit more limited moisture still possibly leading to a period of light snow north and light rain otherwise. The long wave trough will eventually become progressive enough to just push another system through Tuesday, more so with light snow or a mix, which will also introduce cooler temperatures with sprawling surface high pressure by midweek. Confidence in precip type through this window is low due to ice introduction questions. The current forecast is either rain or snow, but a wintry mix is certainly possible. Thus the end of the period looks dry, but with temperatures finally dropping back to just below normal. && .AVIATION.../For the 00Z TAFS through 00Z Friday evening/ Issued at 524 PM CST Thu Dec 23 2021 Main concern is shift to more widespread fog overnight as increase in low level moisture shifts north into region. Latest HRRR runs advecting 40 to 45F Td north by 13-14z with possible 1/4sm to 3/4sm for KALO, KFOD, and KMCW. Farther south patchy MVFR fog expected at KDSM and KOTM. All sites have potential for IFR cigs aft 12z with hint that low cigs may stick around past 18z most areas. Will update trends again with 06z package. /rev && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...REV DISCUSSION...Small AVIATION...REV
Area Forecast Discussion
National Weather Service Grand Rapids MI
700 PM EST Thu Dec 23 2021 LATEST UPDATE... Aviation .DISCUSSION...(This evening through next Thursday) Issued at 330 PM EST Thu Dec 23 2021 --Fog Late Tonight and Early Friday; Mild with Drizzle Friday-- Strong signal in the guidance for some radiational fog developing overnight after skies partially clear behind exiting wave. The fog may become locally dense, which could also lead to some black ice forming where temperatures are below freezing. Main threat would be north of I-96 where subfreezing temperatures are expected overnight. The Friday morning commute may feature reduced visibilities as well as some slick spots up north. Any dense fog should lift by Noon Friday with the help of increasing southerly winds, but extensive stratus and intermittent drizzle expected to linger as dew points above 40 pour in from the south. Highs around 50 south of I-96; remaining in the 40s from I-96 north. --Rain Likely South Christmas Morning-- A cold front leans in from the west on Christmas Eve then stalls as a wave moves along the front. That results in an area of rain impacting places near and south of a Holland to Lansing line on Christmas morning, but it looks to exit by afternoon. Drier air and surface ridging coming in behind the wave should result in mainly dry weather for the remainder of the weekend, but a weak sfc trough/secondary cold front could touch off a few light snow showers near U.S. 10 on Saturday evening. --Systems with Wintry Mix Sunday night and Tuesday night-- Fast jet stream off the Pacific continues to send systems our way about every 48 hours and models have been pretty consistent with the next wave on Sunday night. Strong warm advection coming in atop cold air at the sfc (thanks to the sfc high near James Bay) will create some p-type concerns. This looks like a snow to rain scenario, with a period of freezing rain possible in the transition. More snow than rain is expected near/north of I-96 where a few inches of accumulation seems plausible. A similar looking system comes in for Tuesday night, although this one appears to have a higher freezing rain risk with less in the way of snow accumulation potential. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 659 PM EST Thu Dec 23 2021 Impactful weather for aviation expected for this TAF period, with fairly extensive coverage/duration of LIFR cigs/vis forecast. At the outset, all terminals are reporting MVFR cigs with unrestrictedvis. However, GOES imagery suggests that mid/upper clouds will thin considerably in next few hours, allowing boundary-layer radiative cooling to ensue. This cooling will occur in tandem with the arrival of deeper low-level moisture. BUFKIT overviews of recent HRRR guidance show rather favorable profiles for fog development overnight, and TAFs reflect our expectation of a fairly quick onset of IFR/LIFR conditions. Some marginal improvement in cigs/vis is possible Fri afternoon as stronger flow just above surface promotes near-surface mixing. However, confidence is high that IFR will prevail for this TAF period. && .MARINE... Issued at 330 PM EST Thu Dec 23 2021 The Small Craft Advisory has been marginal due to winds being more out of the southeast than south and not as strong as expected. However the webcam at Grand Haven does reveal rough conditions so will continue it for now. An advisory may be needed for Friday as well as southerly flow strengthens a bit. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory until 10 PM EST this evening for LMZ844>849. && $$ DISCUSSION...Meade AVIATION...Kenyon MARINE...Meade
Area Forecast Discussion
National Weather Service Key West FL
947 PM EST Thu Dec 23 2021 .DISCUSSION... Clear skies prevail across the Florida Keys on this Thursday evening. Radar shows widely scattered light showers over the eastern Straits of Florida, along a low level convergence boundary between NNW and NE flow in that area. Temperatures along the island chain are mostly in the mid to upper 60s, with dewpoints hovering in the lower 50s. Winds on land vary from NE in the Lower/Middle Keys to NNW in the Upper Keys, at speeds of 10 mph or less. Surface analysis depicts high pressure centered along the Carolina coast and sprawling from New England to the northern Gulf of Mexico. The 00Z Key West sounding sampled an extremely dry airmass, with PW of 0.31 inches being a record low for this date. MIMIC-TPW satellite imagery shows a very dry airmass, with estimated PWs below one half inch, continuing to stream SSW from the Florida peninsula across the Keys, with slightly higher PWs around 0.7 inches confined to the far eastern Straits and eastward. Overnight, the only potential fly in the forecast ointment of clear skies and cool temps for the Keys will be the future evolution of the showers currently over the eastern Straits. Typically, NNW drainage flow from the mainland in these regimes is sufficient to keep such shower lines east of the Upper Keys through the night, and that is also depicted by CAM guidance including the HRRR and experimental HRRR-Caribbean. Otherwise, temps appear to be on track to drop only a few more degrees by morning, reaching lows in the lower to mid 60s. Will maintain a clear and dry forecast overnight, with no updates needed. && .MARINE... Evening observations show N to NE breezes running generally in the 10 to 15 knot range along most of the reef, as well as at Smith Shoal Light and Long Key. The exception is off the Upper Keys, where an offshore component from the mainland is maintaining gentle to moderate NNW breezes. Little change is expected overnight, and no significant changes are planned for the late evening forecast issuance. && .AVIATION... VFR conditions will prevail at the EYW and MTH terminals overnight and Friday, with mostly clear skies and no rainfall expected. Surface winds will remain from the NE at 5 to 10 knots through the period. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Jacobson Aviation/Nowcasts....Jacobson Data Acquisition.....SMS Visit us on the web at Follow us on Facebook and Twitter at:
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
513 PM PST Thu Dec 23 2021 .SYNOPSIS...23/1259 PM. Unsettled weather will prevail across the area with periods of rain through Sunday morning. Snow levels will remain quite high today but will drop significantly Friday night into Saturday. Temperatures will be significantly below normal across the region. More rain and mountain snow is expected next week. && .SHORT TERM (TDY-SUN)...23/1255 PM. Southwest flow ahead of an upper low about 600 miles west of Pt Conception continues to usher in moisture with periods of moderate to heavy rain across the area. The HRRR did a poor job earlier this morning projecting 1" rain rates across southern Santa Barbara County and don`t have much confidence in it going forward. Rates topped out only around a half inch and about 3 hours earlier than expected. Still have several hours before the back edge of this moisture stream moves through the area so the potential for moderate to heavy rain will remain at least through this evening. Though it appears the focus will start to shift to LA County later this afternoon and evening. Expecting similar rain rates there, though possibly slightly higher due to somewhat more favorable low level winds providing additional upslope enhancement. Still expecting rates to remain below established debris flow thresholds. Later tonight into Friday morning the upper low will move into the coastal waters near Pt Conception. As it does, colder air aloft will destabilize the air mass and provide a more favorable environment for thunderstorms. The most unstable air will remain over the coastal waters, especially south of Pt Conception so that`s where the best chances of storms will be but certainly can`t rule out a storms drifting onshore. So thunderstorms have been added to the forecast for later tonight into Friday morning for most coast/valley areas south of SLO County. Rain amounts during this period will be much more variable due to the convective nature of the system at that point but on average another quarter to half inch of rain is expected, but with locally higher amounts near storms. Highest south of Pt Conception. Thunderstorm chances expected to end by afternoon as warmer air aloft moves in. Snow levels will also be lowering Friday as the upper low moves through. Should be down to 6000` Friday afternoon, though by that time most of the storm is east of LA County. Friday night through at least Christmas morning should be fairly quiet with only small chances of showers, mainly in LA County. The next system to arrive Saturday evening. This one is a colder and much faster moving system dropping straight out of the north along the west coast. Despite the less favorable trajectory it does have some moisture with it. Ensemble solutions in very good agreement showing amounts mostly topping out around a half inch most coast/valley areas and an inch in the mountains. Snow levels will be much lower, generally 5000` for most of the event but then dropping to as low as 3000` Sunday morning. Precip will be tapering off quickly Sunday morning but light snow accumulations are possible down to 3000` especially north facing slopes that could continue into early afternoon. So this could present some issues for the Grapevine Sunday for people driving through there the day after Christmas. For most other areas Sunday should be a mostly sunny day but cool with highs mostly just in the 50s at lower elevations and 30s/40s in the mountains. .LONG TERM (MON-THU)...23/120 PM. Models continue to advertise an active period of weather at least through mid week and possibly beyond. Another cold and fast moving system will drop out of the north Monday and bring more showers and low elevation snow lingering into Tuesday. Precipitation amounts on the low side due to the less favorable northerly trajectory, though most ensembles are slightly higher with the amounts than the Saturday night system. The bigger impacts from this system would likely be in the mountains with light snow accumulations possibly down to 3000` again. Quite a bit lower confidence in the forecast after that. Ensembles seem to favor the trough lingering over the western third of the US through most of the rest of next week but the GEFS is much drier than the EC ensembles despite the deterministic GFS showing multiple inches of rain over parts of the area. In fact, more than half of the GFS ensemble members have no rain past next Tuesday, possibly a result of the low kicking too far to the west. Will have to give this some more time to percolate and see if we get better consensus in the next few days. Gut feeling is we`ll see the rainy pattern continuing most of next week. && .AVIATION...24/0056Z. At 00Z at KLAX, there was no marine layer or inversion. Low confidence in TAFs as cigs and vis will be changing frequently with rain in the area. Moderate confidence on rain end times. Brief period of LIFR conds are likely in moderate to heavy rain and overnight. There is a slight chance of thunderstorms (10-20%) for KBUR, KVNY, and coastal TAF sites from KSMX south, from 12Z to 18Z. KLAX...Low confidence TAF with cigs and vis varying between MVFR and IFR thru the period. There is a 30 percent chc of brief 1SM RA BR OVC004 conds thru 06Z with heaviest rains. Good confidence in 8 to 15 kt east wind component through 12Z Fri. KBUR...Low confidence TAF with cigs and vis varying frequently between MVFR and IFR thru the period. There is a 30 percent chc of brief 1SM RA BR OVC004 conds thru 12Z. && .MARINE...23/222 PM. Very complicated forecast with lots of rather rapid changes over the next couple of days, with only fair confidence in the forceast. During much of the time thru Mon, conditions will be near or at SCA level in many areas. Across the outer waters, local SCA level gusts may linger through the afternoon for north of Santa Rosa Island. South of Santa Rosa Island, winds are expected to drop below SCA levels by tonight. Then, S-SW winds should remain below SCA levels tonight/Fri morning. Behind the front, winds are expected to become NW and increase to SCA levels Fri afternoon into Fri night. There is a 40% chance of SCA level SW winds Sat afternoon/evening, and seas will also be close to SCA levels. SCA level NW winds and seas are likely Sat night thru Mon. Across the inner waters north of Pt Sal, winds are not expected to reach SCA level through Friday morning. There is a 40% chance of SCA level NW winds Fri afternoon/evening, and SCA level SW winds Sat afternoon/evening. Seas will be close as well. There is a 40% chance of SCA level NW winds and seas Sun thru Mon. Across the SBA Channel, SCA level SE winds are expected to drop by tonight. There is a 20% chance of SCA level W winds Fri afternoon/evening, and a 30-40% chance of SCA level W winds Sun thru Mon. Across the inner waters south of Pt Mugu, there is a good chance of a period of SCA level SE-S winds this afternoon into this evening. There is a 20% chance that SCA level SW winds may develop late tonight and continue thru noon Fri. There is a 30% chance of SCA level NW winds Sun thru Mon. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory in effect until 9 AM PST Friday for zones 53-54. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 9 PM PST this evening for zones 650-655-676. (See LAXMWWLOX). && .HAZARD POTENTIAL OUTLOOK (SUN-THU). An unsettled weather pattern will bring periods of rain and mountain snow to the region through at least the middle of next week. The rain could create slick roads and some travel delays along with moderate snow accumulations and wintry driving conditions to the mountains. && $$ PUBLIC...MW AVIATION...Phillips/Lund MARINE...Lund/DB SYNOPSIS...MW