Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/21/21

Area Forecast Discussion
National Weather Service State College PA
1122 PM EDT Tue Apr 20 2021 .SYNOPSIS... A stalled front draped across northern Pennsylvania will keep a tight temperature gradient in place across the region this evening. Later tonight, an approaching low pressure system will track along the aforementioned front, bringing some accumulating snow to the northwest mountains. Big changes arrive on Wednesday as a strong cold front sweeps through the Commonwealth, potentially creating a few strong to severe thunderstorms during the day and ushering in plummeting temperatures overnight. Near or below-freezing temperatures Thursday morning will precede a gradual warmup through the weekend. Dry weather will prevail Friday into the first part of Saturday. Some showers will be possible later Saturday into Sunday. Dry weather will return for Monday into Tuesday. && .NEAR TERM /THROUGH WEDNESDAY/... A weak shortwave lifting into the region is supporting developing showers along and north of a stalled frontal boundary, which lies across the southeast part of the forecast area. The latest RAP shows a fairly impressive low level jet overrunning the front late this evening. All near term guidance supports bumping POPs up this evening from the south central mountains northeast through around KIPT. By late tonight, surface low pressure will develop over the middle and Upper Ohio River Valley in response to increasing large scale lift beneath the right entrance region of a 90 kt upper jet just to the north of PA and 130 meter 500 mb height fall center headed our way from Indiana/Illinois. This system will have enough cold air across the northwest mountains PA to produce some wet snow tonight - perhaps a few locations surpassing the 3inch mark in far NW Warren county, but probably nothing as far south as I-80. Model soundings also indicate a brief period of freezing rain or sleet is possible over the northern mountains late tonight, although accumulation will be insignificant and impacts non-existent owing to warm antecedent surface temps. As low pressure moves northeastward off the coast, a strong cold front will sag southward across the Commonwealth during the day on Wednesday. This cold front will traverse the Susq Valley during the late morning hours with the western edge of any appreciable ML CAPE likely impacting just our far eastern zones like SE York, Schuylkill, Lancaster and Lebanon counties where a few TSRA are expected and SPC has a MRGL Risk for SVR painted. By the time the cold front passes through, rainfall totals are forecast to be less than 0.10 inch across the Laurels and south central PA, with 0.10 to 0.40 inch of precip expected north of I-80. This precipitation should help put a dent in the ongoing drought conditions in the northwest mountains. In the wake of the cold front, plummeting temperatures and gusty winds will spell a noticeably chilly afternoon. Winds will gust over 30mph south of I-80. Daytime highs will occur ahead of this front in the southeast zones, topping out in the low 60s by about 11AM. By nightfall tomorrow, temperatures will range from the mid 30s across the northwest to near 50 in the southeast with wind chills well down into the 20s. The NW flow will also bring in the return of lake effect showers, which will mix with snow before nightfall in the west and turn to plain snow showers early Wed evening. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/... Lingering lake effect and upslope snow is likely to result in a fresh coating of accum across the north and Laurels Wed night, esp on the higher elevations. Temps will continue to cool with mins in the mid 20s to low 30s by Thursday morning. With another group of south central PA counties scheduled to begin their growing season on Apr 21, we will have to monitor low temps for freeze warning criteria Thu AM. It does look like it will be too windy for frost formation. Thursday will be another blustery day with gusts into the 30s possible. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... 10 pm Tuesday update... Our various ensemble prediction systems are in good agreement on the large-scale pattern into next week. There will be a tendency for upper troughiness to persist over eastern Canada and the northeastern U.S. through the upcoming weekend, followed by height rises early next week, as an upper low is forecast to shift eastward from the Canadian Maritimes into the north Atlantic. In general, this set up will produce near to below average temperatures for late April across the Commonwealth through Sunday, with some moderation likely for the early and middle portions of next week. After a cold night Thursday night, Friday should feature a fair amount of sunshine, but with readings still somewhat below normal (highs in the 50s-lower 60s). Much of Saturday should remain dry, with highs generally in the 60s. A period of rain appears likely Saturday night into Sunday, as a well formed upper trough crosses the Commonwealth, and an intensifying surface wave rides up the eastern seaboard. Next week, things should dry out, with temperatures on the rebound. In fact, by Tuesday, depending on the ultimate position of a warm frontal boundary, highs could pop back into the 70s for at least portions of south-central PA. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... 00z update... A broken band of showers/isolated thunder has developed early this evening along a frontal boundary draped across PA. A near-term threat of thunder in the vicinity of KIPT through 01-02z, with generally VFR elsewhere. Later tonight (after 06-08z), ceilings should lower into the fuel alternate-IFR categories, with a period of snow early Wednesday at KBFD. Surface winds turn NW and become quite gusty during the day Wednesday well behind the cold front. Frequent IFR snow showers are foreseen at KBFD and KJST, with conditions gradually improving to VFR elsewhere by afternoon. Outlook... Thu...Northwesterly flow, with restrictions and spotty rain or snow showers N/W PA. Fri...Still windy early, but mainly dry. Sat...Restrictions possible as rain approaches from the SW late. Sun...Widespread showers, tapering off late. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Martin/Banghoff NEAR TERM...Fitzgerald SHORT TERM...Fitzgerald/Banghoff LONG TERM...Jurewicz AVIATION...Jurewicz/Martin
Area Forecast Discussion...UPDATED
National Weather Service Chicago/Romeoville, IL
906 PM CDT Tue Apr 20 2021 .UPDATE... 905 PM CDT The going forecast and message are both in good shape through tonight and rolling into Wednesday. Did hang onto some snow showers/flurries through later tonight, and have boosted Wednesday afternoon PoPs further over far northeast Illinois. Scattered showers -- primarily snow showers -- continue to fester this evening across the area, with the greatest coverage 20 miles east/west of I-55 as of 9 PM. These are persisting under a 500 mb vorticity maximum and upper level jet streak moving slowly eastward. These showers should very gradually fade into the overnight, however some light snow/flurries may redevelop in northeast Illinois under subtle isentropic ascent late tonight. With near record seasonal cold 850 mb temperatures of -6C to -8C, much of the cloud cover has been more closed-celled cumulus and lingering longer after dark. This should prevent surface temperatures from dropping too much, however readings are already in the 30s in most areas so it remains on track to drop below freezing. Some clear pockets could develop and within these holes are where a hard freeze would be most favored, primarily in outlying locations. So no changes made to current Freeze Warning. Looking upstream, the well-defined closed upper low across eastern South Dakota/western Minnesota is slowly moving southeast with an area of moderate to briefly heavy snow showers. The 00Z ABR sounding showed steep lapse rates through 600 mb due to 700 mb temperatures of -20C (near or record cold for this time of year). The forecast RAP and HRRR soundings for northeast Illinois Wednesday afternoon resemble this observed sounding, and so would expect similar behavior to what was observed in that area this afternoon and early evening (scattered moderate-heavy snow showers). Northeast Illinois remains the most favored area both synoptically in the mid-levels (PVA) and also on the mesoscale in the low-levels (wind convergence and surface-based positive CAPE). Have increased the PoPs in Lake and Cook Counties since our confidence has increased, and because of the convective nature seen upstream and shown in guidance, have added heavy mention to account for the likelihood of temporary very low visibility in heavier snow/graupel rates. MTF/BKL && .SHORT TERM... 325 PM CDT Through Wednesday night... [Through Tonight] Our primary band of frontogenetically driven moderate snow is now shifting over my far southeastern counties in east central IL and into parts of northwestern IN. Expect this band of snow to continue to shift out of this area early this evening. Otherwise, some scattered snow showers will persist this afternoon and into the evening, primarily over inland areas of northern IL west of the immediate Chicago area as a weak surface trough drops southward over the area. The combination of steep low-level lapse rates and some modest boundary layer convergence with this trough into this evening may support some brief localized bursts of snow with these showers, but no more than a coating on grassy surfaces is anticipated. This activity may begin to wane overnight, before additional snow showers develop for Wednesday. In spite of the cloud cover across the area for most of the night, temperatures are still expected to fall below freezing tonight in most locations, and few areas could drop into the upper 20s. For this reason, we have made no changes with the going freeze warning headline. KJB [Wednesday] Main concerns are with snow/graupel showers and gusty squalls along with isolated thunderstorms during the day on Wednesday and then another freeze late Wednesday night, mainly outside downtown Chicago. There are a few good analogs for the synoptic set-up tomorrow, namely April 2, 2016 and October 20, 2018, which both had scattered to numerous snow/graupel showers and squalls. A strong 500 mb vorticity lobe on the west side of unseasonably deep and cold upper low over the eastern Lakes will pivot across the area from the late morning through mid afternoon. 500 mb temps of -30 to -35C, essentially off the charts cold per late April sounding climatology, and the strong mid-late August equivalent sun will yield very steep low and mid-level lapse rates, nearly dry adiabatic in the 0-3km layer. Forecast soundings indicate an inverted V look roughly in that layer. The result will be a couple hundred J/kg of SB CAPE and some DCAPE as well. A strong lake enhanced convergence axis will set up across northeast Illinois and northwest Indiana to provide a low- level focus for the large scale lift from the vort lobe. Anticipating convective processes to get going pretty quickly during the morning. With wet bulb zero heights below 1kft AGL and the very dry sub-cloud layer, despite temps getting up into the 40s outside convection, expect much of the showers to feature snow and graupel as temperatures under them rapidly cool down into the 30s. Most widespread/numerous coverage is forecast to be in the aforementioned lake enhanced convergence axis toward mid day and through mid afternoon. Strong large scale and mesoscale lift and convection will yield at least isolated embedded heavy showers/squalls, with low freezing levels supportive of isolated lightning strikes and graupel. Looking back to the 2016 and 2018 events, the heaviest squalls had brief heavy snow/graupel with very poor visibility and strong wind gusts, along with a few lightning strikes. Primary difference between those events and tomorrow is weaker wind fields aloft. That said, the deep mixing, steep low level lapse rates, and DCAPE should support gusts up to 30-40 mph in the heaviest squalls, which would knock down visibility farther. Even with the highest shower coverage closer to Lake Michigan, still expecting scattered coverage inland given the good large scale lift. Wouldn`t be surprised to see a quick couple tenths of snow under heavy snow/graupel squalls, though mild pavement temps should keep the impacts mainly as brief low to poor visibility and rapidly changing conditions. Castro && .LONG TERM... 325 PM CDT Wednesday Night through Tuesday... Large scale upper trough is progged to be moving off to the east of the area Wednesday night, though with one last smaller scale short wave rotating east-southeast into the departing trough axis. Cold mid-level temps associated with this wave/departing upper trough (around -22C depicted at 700 mb) combined with a deeply mixed boundary layer (adiabatic lapse rates from the surface up to 700 mb) will likely continue to support isolated to scattered convective rain/snow showers early Wednesday evening. Loss of diurnal low level instability and passage of the short wave trough axis should allow these showers to dissipate by late evening, with subsidence developing across the region after midnight and inducing clearing skies. Clearing within the cold airmass is expected to aid in producing widespread freezing temperatures across the forecast area, with lows in the upper (locally mid) 20s outside of the core of the Chicago metro area by sunrise Thursday, with low-mid 30s in the city. We`ll very likely need freeze warning headlines again for Wednesday night, but for simplicity at this time we`re continuing to mention the Wednesday night impacts in the additional information section of the current headline in effect for tonight. Mid-level short wave ridging then develops across the area Thursday into Thursday night in the wake of the departing upper trough. Strong 500 mb height rises in excess of 80 meters is progged across the area initially Thursday, indicative of deep large-scale subsidence. Along with very dry thermodynamic profiles, subsidence should promote plenty of sunshine across the area and allow a quick rebound of temperatures back into the mid to upper 50s, and somewhat breezy west winds limiting lake breeze potential. Guidance remains in general agreement in depicting a low-amplitude mid-level short wave approaching the mid/upper Mississippi River valley later Thursday night, which would likely bring increasing high cloud cover into the region after midnight. Lows will likely dip into the 30s outside of Chicago in the dry air mass prior to the arrival of high clouds however, possibly producing some patchy frost into early Friday. This mid-level wave is then progged to dampen across the region Friday, as it propagates into the upper ridge position. Low level return flow develops across the Plains in association with this feature, but becomes weaker and less-focused as the amplitude of the disturbance decreases across our area. Lower and mid level southwest flow does provide warm/moist advection into the region by Friday afternoon however, with NCEP guidance depicting the potential for spotty showers across interior northern and central Illinois later in the afternoon. Certainly possible per ECMWF that the lower and mid-level dry air hangs tough through the day though. Global models continue to show some differences with a couple of additional short waves within developing northern and southern streams Friday night into Saturday, though the general consensus remains for shower chances to persist into the day Saturday as these waves move east and a cold front associated with the northern stream wave pushes through the area. Temperatures do continue to moderate Friday into Saturday with southwest low level flow, though this will likely be modulated by increased cloud cover and a potentially stronger southern stream low as again noted in the ECMWF and ECS ensemble runs. Highs both days should be near 60, and possibly into the mid-60s on Friday if cloud/shower coverage are lower than forecast. A stronger southern stream low per the ECMWF would also result in a greater potential for onshore surface winds and cooler temps off of Lake Michigan however on Saturday. Both of these short waves and their developing larger scale upper trough are progged to move off to the east of the area Saturday night with a broad, flat upper ridge depicted across much of the central CONUS by Sunday. Associated surface high pressure moves across the forecast area during the day, allowing dry weather and likely some lake cooling (upper 40s to around 50) with temps in the 50s to near 60 inland expected to round out the weekend. Upper ridge is then progged to amplify across the central CONUS/Midwest early next week, in response to an upstream long wave trough moving into the West Coast. Developing southerly flow behind a warm front lifting into the region should support warmer temps (perhaps 70s) by Monday, with the best potential for warm advection showers/storms currently looking to remain off to our northwest through the day on Tuesday. That said, precip chances aren`t zero on Monday, with ECMWF showing spotty elevated convection tied to the lifting warm front. At this vantage point, Tuesday currently looks breezy and warm (near/around 80F) and most likely capped to convection through the daylight hours. A rather potent system could take shape from the ejecting western trough beyond day 7, with shower/thunderstorm chances a decent bet. Ratzer/Castro && .AVIATION... For the 00Z TAFs... Aviation weather concerns this period consist of: * Low threat for BR/low cig re-development late tonight, as well as a -SHSN or two * Developing gusty northwest winds through Wednesday morning and afternoon * Convective rain/snow/graupel showers into Wednesday afternoon, especially across northeast IL/northwest IN with some lightning threat * Northeast winds into ORD/MDW/GYY late in the afternoon Spotty -SHSN continue away from the terminals early this evening, and anticipate this will remain the case as drier air has filtered across the Chicago-area sites. Hi-res guidance is suggesting that some of the low cigs currently across central Illinois may drift back northward late tonight/Wednesday morning as the low-level flow veers. Confidence in this occurring, or resulting in low cigs and some light BR was too low to justify a formal mention in the outgoing TAFs, but we`ll continue to keep an eye on trends. A weak disturbance will pass overhead in the 10-15z time frame. It`s possible this results in some very spotty precipitation (-SHSN) but again coverage and confidence remains under 30% at this time. Breezy northwest winds will develop through Wednesday morning and afternoon, with a lake-enhanced boundary expected to develop with time. As a result, a northeast wind shift will likely remain in very close proximity to ORD/MDW, lending low confidence in the wind trends into the early afternoon, with better confidence in a northeast wind shift late in the afternoon. A deeply-mixed environment will result in pockets of sufficient instability for electrification as precipitation develops Wednesday morning and afternoon. Have maintained the inherited VCTS during the 18-23z window due to this potential, as well as the likelihood of convective tops in the vicinity. Temperatures will warm into the 40s, but the convective nature of activity will likely support frozen precipitation, but little/no accumulations are expected given the temperatures. Precipitation will wane into Wednesday evening with the loss of daytime heating. Carlaw && .LOT WATCHES/WARNINGS/ADVISORIES... IL...Freeze Warning...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ023-ILZ032- ILZ033-ILZ039-ILZ103-ILZ104-ILZ105-ILZ106-ILZ107- ILZ108...midnight Wednesday to 9 AM Wednesday. IN...Freeze Warning...INZ001-INZ002-INZ010-INZ011-INZ019...midnight Wednesday to 9 AM Wednesday. LM...None. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Updated for 00Z Aviation Forecast Discussion below.

PREV DISCUSSION... /issued 250 PM CDT Tue Apr 20 2021/ DISCUSSION... Much of the CONUS will remain under the influence of a longwave trough over the next several days. This trough will bring near record cold and a potential frost/freeze to portions of the Mid- South late tonight and possibly again Wednesday night. A sharp cold front currently extends from west-central AR, across southeast AR, and along the OH River. Temperatures behind this front are in the 40s and 50s, while areas in the warm sector are currently in the 70s. This front will sweep across the Mid-South overnight. Gusty northwest winds are expected in the wake of this boundary with gusts of 25-30 mph for a few hours. Strong cold advection will usher in much colder air, with temperatures falling into the 30s across most of the CWA by sunrise. A light freeze is expected across northeast AR into far northwest TN, but it does look to be confined to a brief period around 12z. Surface winds of 5-10 mph may result in sufficient mixing to limit significant damage to vegetation, but protective actions are recommended. This freeze is marginal and all areas in the warning may not reach 32F, but I prefer to err on the side of caution given the given the state of the vegetation and the date. Scattered showers are likely ahead of this front from late this afternoon into the overnight hours. mPing reports upstream over the higher terrain of the Ozarks are either all snow or a mix of rain/snow. Point soundings along the northern tier of counties in the Mid-South are supportive of a mix of rain/snow overnight. That said, warm ground and low QPF will result in no accumulation. This activity will end from west to east overnight, with nil PoPs by Wednesday. Transient shortwave ridging behind the departing trough will lead to dry weather on Wednesday and Thursday but temperatures will remain well below climatology. Highs on Wednesday are expected to remain in the 50s with many areas warming back into the low/mid 60s for Thursday. A frost is possible for some areas across the Mid-South early Thursday morning. A 1028 mb anticyclone will build over the Mid-South, resulting in light winds and dry air. However, increasing mid/upper-level cloud cover could preclude a full decoupling of the boundary layer and may keep temperatures just warm enough to limit this frost potential. The main area of concern will west TN and northeast MS where cloud cover would arrive later. MOS continues to indicate minimum temperatures of 32-36F while the blends favor a warmer solution. Given the track record of model guidance in radiational cooling scenarios, I`m trending in the cooler direction (at least for the areas that remain mostly clear). No headline will be issued at this time for Thursday morning, but one may be necessary eventually. The trough that is forecast to affect the Mid-South late week looks to weaken as it moves across the area before eventually phasing with the northern stream over the Mid-Atlantic region. Showers, and a few thunderstorms, are expected Friday into Saturday, but the severe weather threat will likely be confined to the Gulf coast. Rainfall amounts exceeding 1" are most likely across north MS. The air mass associated with this wave will be of Pacific origin and should actually be warmer than what it is replacing. Thus, expect pleasant weather Sunday into Monday with temperatures climbing back above climatology by the latter. A deep trough is poised to affect the area midweek. The 12z deterministic global models (as well as their ensemble means) build a ridge up the east coast ahead of this trough. This causes the trough to slow and lift more northeast as it moves out of the Plains. We`re looking at an increasing potential for showers and thunderstorms to round out the forecast period, but the severe weather threat will be significantly influenced by the strength of the East Coast ridge. We`ve got plenty of time to assess this potential. MJ && .AVIATION... 00Z TAFs Primary concern is winds this evening. Following frontal passage, observed gusts have been in line with guidance. KNQA VAD wind profiler showed winds 34030KT between FL020-030. This should represent the maximum gust potential through 03Z or so. Thereafter, low level pressure gradient and pressure advection will ease up, likely limiting MEM gust potential by 08Z. A narrow band of MVFR ceilings may be accompanied by -SHRA at MEM, and perhaps a brief -SHRA/SN mix at MKL late this evening. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Freeze Warning from 3 AM to 9 AM CDT Wednesday for Clay- Craighead-Greene-Mississippi-Poinsett. MO...Freeze Warning from 3 AM to 9 AM CDT Wednesday for Dunklin- Pemiscot. MS...None. TN...Freeze Warning from 3 AM to 9 AM CDT Wednesday for Dyer-Lake- Lauderdale-Obion-Weakley. && $$
Area Forecast Discussion
National Weather Service San Francisco Bay Area
625 PM PDT Tue Apr 20 2021 .SYNOPSIS...A slight chance of showers or an isolated thunderstorm across the hills of Napa and northern Sonoma county late this afternoon through sunset. Otherwise clear to partly cloudy and seasonably cool overnight. Dry and seasonal weather returns Wednesday through Friday. Increasing clouds Saturday leading to a chance of rain by Sunday. && of 2:21 PM PDT Tuesday...Low clouds have lingered into the afternoon around SFO as well as coastal San Mateo and the Monterey Bay region. Inland skies have cleared but temps remain coolish in the 60s and lower 70s with brisk onshore winds. The onshore winds are being amplified as a potent shortwave trough drops southward over the Central Valley this afternoon. SFO has been gusting in excess of 35 mph with gale force gusts noted at several of the coastal buoys. This upwelling has dropped sea surface temps into the upper 40s, thus the chilly temps at area beaches as clouds and onshore breezes persist. Short term focus from now through about sunset will be possibility of showers and isolated t-storms, mainly around Mt Saint Helena and the higher terrain of northern Napa county. Satellite imagery shows cumulus clouds rapidly starting to develop as potent shortwave and associated steep lapse rates will allow for rapid destabilization over the next several hours. Usually under these type of events the precip stays over Lake County and points northward. However, the shortwave is progged to drop right down the Central Valley. Thus orographics, afternoon heating and dynamic forcing all coming into play. Mesoscale model simulations such as HRRR and RAP keep showing activity this evening so confidence is higher than normal that well see some showers/t-storms. Rainfall amounts shouldn`t be too heavy with main concerns for some small hail, gusty outflow winds and possible lightning strikes. Cant completely rule out new fire ignitions with any strikes but that is remote possibility and low chance scenario. Again, nearly all areas will remain dry and the above covers mainly the higher terrain of Napa and extreme northeast Sonoma county through sunset. The shortwave will quickly move east of the region by Weds morning. This will leave the area in a seasonable weather pattern with dry weather except for coastal drizzle. Northerly flow behind the trough may bring the most warming to the North Bay with temps back into the 70s and lower 80s. Other portions of the Bay Area may not be quite as warm as westerly onshore winds will prevail through the end of the work week with highs 60s and 70s. Saturday should see increasing clouds with onshore winds as temperatures cool slightly ahead of incoming late season trough. Ensembles and deterministic models in good agreement that a fairly strong late season cold front will bring rain to the region on Sunday. System will be dropping out of the Gulf of Alaska and be fairly fast moving which will limit rainfall totals. Nonetheless early estimates suggest 0.25-0.50 potential for much of the Bay Area with higher amounts North Bay hills and Santa Cruz mountains. No, not nearly enough to make much of a dent for the ongoing drought. However, snow in the Sierra with a solid wetting rain would at least slow the onset of fire season which is a good thing. Will continue to monitor and update over the coming days. && .AVIATION...As of 06:30 PM PDT Tuesday...For the 00Z TAFs. Widespread MVFR at several of the Bay Area and Central Coast terminals this afternoon with cigs between 1500-2000ft. Strong onshore flow also being observed regionwide as a low pressure from the north increases the north-south gradient and produces 20-25kt winds with occasional gusts >30kts along the San Bruno Gap. Thunderstorms have also been approaching the KAPC terminal this afternoon but have gradually weakened on their approach so only expecting VCSH at KPAC along with a slight chance for some isolated showers to approach KSTS. Showers are not expected to survive beyond the North Bay terminals this evening. Marine stratus will persist this evening and reintroduce MVFR to many of the coastal and interior terminals tonight and into tomorrow morning owing to the enhanced onshore flow from the low pressure system to our north increases the SFO-ACV gradient. The exception will be the North Bay terminals, as drier offshore winds (N/NE) following the passage of the low pressure system will impede marine stratus development and intrusion north of the Golden Gate. Vicinity of KSFO...MVFR conditions with BKN skies at the KSFO and KOAK terminals along with strong onshore winds between 20-25kts at KOAK and gusting to 40-45kts at times at KSFO. Will see a gradual decrease in wind intensity after 9Z as the low pressure to our north begins to exit the region, but the strong onshore push from the day will allow for the continuation of stratus intrusion through the overnight and into tomorrow morning. Ceilings will improve by daybreak (mixed MVFR and VFR) and will observe a lull in winds through much of the morning but winds onshore flow will pick up to 10-15kts by the end of the TAF period. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...MVFR/IFR with clouds likely remaining around terminals through the day. -RA/DZ will be intermittent this afternoon for KMRY. Winds will be onshore and gusty through most of the TAF period. Winds will eventually subside late in the TAF period and any terminals that saw brief clearing will return to MVFR conditions with cigs between 1000-1500 feet. && of 01:17 PM PDT Tuesday...Currently strong northwest winds with gale force gusts over the northern waters and down the Big Sur coast today. These strong winds in the northern waters will combine with a northwest swell to produce steep seas 11 to 13 feet at 11 seconds this afternoon and evening, resulting in hazardous seas conditions particularly for smaller vessels. The gusty winds are expected to persist through tonight. The northwest swell continues through the week. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tday...SCA...Pt Reyes to Pigeon Pt 0-10 nm until 3 AM SCA...Pigeon Pt to Pt Pinos 0-10 nm until 3 AM GLW...Pt Arena to Pigeon Pt 10-60 nm GLW...Pt Arena to Pt Reyes 0-10 nm until 9 PM GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm until 9 PM SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 9 AM SCA...Mry Bay until 9 PM SCA...SF Bay from 2 PM && $$ PUBLIC FORECAST: RWW AVIATION: Diaz/Canepa MARINE: Dhuyvetter Visit us at Follow us on Facebook, Twitter, and YouTube at: