Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/27/18


Area Forecast Discussion
National Weather Service Bismarck ND
1031 PM CDT Sun Aug 26 2018 .UPDATE... Issued at 1030 PM CDT Sun Aug 26 2018 Cancelled the Tornado Watch for this update. The severe threat has ended for western and central North Dakota tonight as the upper level wave has pushed off to the east. UPDATE Issued at 740 PM CDT Sun Aug 26 2018 Main change for this update was the issuance of a Tornado Watch for the southeast. Storms are developing along the warm front. While there is a slight cap to deal with across the southeast, there should be enough forcing with the upper level wave swinging through to break through the cap and support robust convective development over the next 1 to 4 hours. All severe threats are possible with storms that develop along the front, including a tornado, due to the impressive shear profile and modest instability. The upper level wave is moving rather quickly across the state and therefore all thunderstorm activity should move out of the area by around 11 pm CDT. UPDATE Issued at 535 PM CDT Sun Aug 26 2018 Storms have been slow to develop so far this evening, but we are seeing more robust development within the past hour as the main upper level wave enters western North Dakota. The warm front remains across far southern North Dakota. This is where the main axis of instability has set up. Further north instability quickly diminishes. However, shear remains quite high across the entire area. Presently, what we are seeing is elevated cells develop further south, just north of I-94, along the gradient of instability. These cells rapidly intensify as they push north into higher shear, potentially producing penny to quarter hail and gusty winds as they do so, then they tend to weaken as they leave the deeper instability behind. We expect this trend to continue through the evening. Short-term models are advertising the warm front becoming more active after 7 pm CDT. Any storms that develop along the warm front have a much higher potential for being severe with higher end severe threats. At this time it would appear Dickey and LaMoure Counties have the best chance at seeing this development later this evening. && .SHORT TERM...(Today and tonight) Issued at 344 AM CDT Sun Aug 26 2018 The main forecast concerns are with chances of thunderstorms and the risk of severe storms this afternoon and tonight. Currently, a surface low was near Pierre SD with a warm front northeast to around Aberdeen and then east southeast into west central MN. Current RAP analysis and forecast shows the warm front lifting into the southern James River Valley by around 23 UTC. This area will exhibit the most favorable instability and low level helicity, in addition to strong bulk shear. As you go farther north and west from the southern James River Valley, things become more uncertain. Low level stratus remains over a good portion of the southwest and south central, and is now also pushing into the north central this is currently having an negative impact on the CAPE and low level lapse rates. RAP forecast does show moderate ML CAPE of 1000-2000 J/KG lifting into west central through south central ND, with low and mid level lapse rates also trying to push northward into this region. Latest CAMS are not real keen on producing discrete cells over the west central into the south central portion of the state. This would be the favored area for more discrete cells to form, compared to farther north where bulk shear is more parallel to the boundary. And this was depicted by the cams earlier this morning. Not saying that we are not expecting severe weather at all now in the west central to south central,(some of the Cams are going back and for with convection developing here, but weaker than this morning) but our confidence is less in this happening now. Farther north, along and north of the Highway 200 corridor. Cams are still generating significant precipitation here. And with the strength of the shortwave trough approaching from MT, that seems reasonable. The problem is that this area is currently experiencing mid 60 to mid 70 temperatures and dew points in the 40s. Recent radar trends indicate storm tops are quickly being sheared as storms develop. It remains to be seen if any additional heating, and especially increased mid level forcing with the approaching trough will be sufficient enough to generate more upright convection. The threat for hail seems minimal across the northwest and only a little better in the north central with the greatest severe threat being strong winds, if we can get convection strong enough to force the very strong flow aloft, down to the surface. Again, confidence here is lower than this morning for severe winds, but not zero due to the very strong bulk shear and the strong approaching shortwave trough. Convection exits most of the forecast area by midnight, but lingering showers and isolated thunder could linger along the International Border into Monday morning. .LONG TERM...(Monday through Saturday) Issued at 344 AM CDT Sun Aug 26 2018 Another round of showers and thunderstorms is expected to traverse the state on Monday and Monday night. However with cooler temperatures at the surface and aloft, instability will be lacking and severe convection is not expected at this time. Nearly zonal flow returns to North Dakota Tuesday night through Friday, with a gradual warming trend beginning on Wednesday. The latest blend of model guidance suggests temperatures will warm back into the upper 70s to mid 80s for highs on Wednesday through Friday. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 535 PM CDT Sun Aug 26 2018 Storms continue across northwest and north central North Dakota this evening, impacting KMOT. Storms will push eastward with time and could potentially impact KBIS/KJMS. Any storms that do develop will have the potential for strong gust winds and large hail in addition to IFR-MVFR cigs and vsbys. Behind the convection, flow turns north and widespread MVFR to IFR ceilings are progged to develop, lasting through 18Z Monday. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...JV LONG TERM...JV AVIATION...AJ
Area Forecast Discussion
National Weather Service Charleston SC
943 PM EDT Sun Aug 26 2018 .SYNOPSIS... Atlantic high pressure will extend across the area through the work week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... High resolution guidance is beginning to narrow in on a potential dense fog event for the morning commute. The 26/23z run of the NARRE-TL pings a >60% chance for dense fog across much of Southeast South Carolina away from the immediate coast with the highest probabilities clustered in the KRBW-KCHS-KMKS corridor. Per coordination with neighboring WFO`s, have opted to hold off on the issuance of a Dense Fog Advisory in hopes the overnight shift will be able to fine tune the fog forecast even more before the morning rush. Only minor tweaks were made for the late evening update. High pressure will remain anchored to the region tonight. Lingering showers near the Savannah Airport at 26/2230z will quickly weaken through sunset with mainly dry conditions prevailing through the overnight period. Could see some nocturnal convection redevelop over the Atlantic after midnight, but most of this activity should remain along the western wall of the Gulf Stream. The main concern for tonight centers on the potential for fog and stratus. Atmospheric profiles look a bit more favorable for fog/stratus to develop after midnight with depending low-level moisture (courtesy of a southeast low-level flow) forecast to pool beneath a sharpening nocturnal inversion and a clear sky within a decoupled boundary layer. Model condensation pressure deficits are forecast to be lowest roughly along/north of the I-16 corridor in Southeast Georgia and along/inland of U.S. 17 in Southeast South Carolina and this is the region that will see the best chances for significant fog development early Monday morning. This is agreement with the latest SREF, H3R and RAP fog prognostication. Similar to this morning, the fog could be dense at time with visibilities 1/4 mile or less. A Dense Fog Advisory could very well be needed for some locations overnight. Will continue to hit the fog forecast fairly hard, maintaining "areas of fog" and "patchy dense fog with vsbys 1/4 mile or less" qualifiers. Might introduce some widespread fog wording with the late evening update once the early morning hours come into the NARRE-TL guidance`s temporal window. Lows will range from the lower 70s inland to the upper 70s/near 80a the beaches. A few upper 60s will be possible across the more sheltered areas well inland. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... A deep layer Atlantic ridge axis will extend over the northern half of the forecast area through the period. Moisture will gradually increase through mid week, with PWs rising from about 1.5 inches on Monday to around 2 inches by Tuesday and Wednesday. Although the proximity of the ridge will help to suppress convection, feel there will be enough deep layer moisture, and combined with the afternoon sea breeze each day, will warrant slight chance to chance PoPs. Temperatures are expected to be slightly above normal, with highs ranging from the lower 90s inland, to the mid to upper 80s closer to the coast. Lows in the lower to mid 70s, except upper 70s near the coast. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... An expansive deep layered ridge will remain over the western Atlantic and far eastern United States through the extended period. Isolated mainly diurnal convection is anticipated with highs in the low 90s. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... KCHS: There are increasing probabilities for fog/stratus impacts early Monday. It does appear the terminal will be on the eastern fringe of the best fog/stratus parameters, but latest short term guidance continues to trend lower with cigs and vsbys. Will highlight fog reaching the terminal by 08z with prevailing vsbys/cigs dropping to alternate minimums by 10z. Given what occurred this morning, will also introduce TEMPO conditions of 1/2SM FG BKN002 10-12z, but hold off on showing conditions below airfield minimums at this time since the terminal is forecast to be right on the edge of the more favorable fog parameters. The fog/stratus should quickly lift by 14z with VFR conditions prevailing thereafter. KSAV: Main concern centers on fog/stratus potential. Right now, it appears the terminal will remain just east/south of the most favorable fog parameters so will continue to favor a fairly conservative forecast for the early morning hours. Will only show a TEMPO for MVFR vsbys/cigs 10-12z, but if guidance starts to shift the axis of better fog parameters south or east, lower conditions may need to be introduced with the 06z TAF cycle. Once fog/stratus lift, VFR conditions will prevail. Extended Aviation Outlook: VFR conditions are expected to prevail both sites through the week. However, a gradual increase in deep layer moisture through the week is expected to lead to isolated to scattered mainly afternoon showers and thunderstorms each day, which could result in very brief flight restrictions. && .MARINE... Tonight: A coastal trough will continue to lose definition with high pressure becoming the dominant feature. E to SE winds around 10 kt will diminish and become more or less light and variable. Seas will average around 2 ft. Will have to watch for possible fog development in the Charleston Harbor early Monday, which could drop vsbys below 2 NM at times. Monday through Friday: No highlights are expected through the period. Atlantic high pressure will prevail through the work week, with mainly southeast winds of 15 knots or less and seas of 2 to 3 feet. Isolated to scattered mainly late night and morning showers and thunderstorms are possible. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$
Previous forecast discussion... Very warm and humid conditions
will continue into Tuesday with temperatures running 5 to 10
degrees above normal. Dewpoints will be especially oppressive with readings in the lower to mid 70s. This morning`s residual convection and lingering low clouds help limit heating today despite warm advection aloft. There is plenty of MLCAPE this afternoon with little CIN but no apparent trigger is seen to initiate convection. The HRRR model produces a few weak echoes in the southern counties this evening but confidence is rather low. Some showers and storms are possible on Lake Erie later tonight as the more organized activity over the upper Midwest tracks east across Michigan. Monday will be several degrees warmer than today due to increased sunshine and warmer temperatures aloft. Dewpoints will still be oppressive and heat indices will reach from 95 to 100 west of I-71. Widely scattered showers and thunderstorms could develop in the afternoon mainly over the southeast half of the forecast area. Monday night will be muggy with gradual cooling into the 70s with little in the chance for rain as ridging aloft prevails. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Main focus of the short term forecast is a cold front that is expected to move through the area Wednesday afternoon through Thursday. Models have come in a bit slower with the frontal passage with the 12Z runs, and have slowed down pops accordingly. The GFS is still the fastest piece of guidance, while the NAM/GEM are significantly slower. The ECMWF is a nice compromise for now, with pops mirror the overall trend of the 12Z run. Either way, dry conditions are expected Tuesday and Tuesday night with a strong Bermuda high still influencing the eastern CONUS, with continued return flow and above normal temps across the area. Have pops coming into the area through the day on Wednesday, but held of likely pops until the afternoon across the northwest and the evening/early overnight elsewhere. With the slower trend of the front, have kept a low chance/slight chance pop in for Thursday across most of the area. For temperatures, went close to the warmest MOS guidance for highs on Tuesday. Went a degree or two warmer for highs on Wednesday with the slower front, with much cooler temps expected on Thursday behind the front. Highs should remain in the mid/upper 70s Thursday. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Very few changes made to the long term today. The period will start out quiet with high pressure off to the north. Will try for dry weather through midday Saturday and after that will need to keep precip in the forecast. The long range models continue to show differences but both the GFS and ECMWF hint at a cold front over the western lakes on Saturday. This front will try to push across the local area on Sunday. Given the uncertainties will keep the precip mention in the chance category beginning late Saturday in the west and continuing through Sunday all areas. It will hardly feel like early fall with dewpoints well into the 60s during the period and highs both Saturday and Sunday mainly in the middle 80s. && .AVIATION /00Z Monday THROUGH Friday/... The critical period over the next 6 hours should be completely VFR, with some mid-upper level clouds moving across the area. Given the very moist moist air mass that has settled over the area, some patchy MVFR fog is expected to develop by 09Z and dissipate just after sunrise with it completely gone by 14Z. The GFS LAMP model guidance suggests that brief IFR fog could be possible especially at KYNG and KCAK near sunrise between 11-13Z, so included a TEMPO for them. OUTLOOK...Non-VFR possible in showers/thunderstorms possibly late Tuesday night and Wednesday. && .MARINE... Quiet weather expected on the lake for the next few days as a large area of high pressure centered over the Carolinas will bring southwest winds over the region. Winds will generally be in the 5-15 kt range through Monday night, increasing to 20 kts on Tuesday. A cold front will push across the lake Wednesday and Wednesday night, with winds becoming northwest behind the front, likely bringing small craft advisory conditions to at least the eastern half of the lake for a period of time Wednesday afternoon/evening. High pressure will build across the lake Thursday through Friday, with light north winds slowly becoming southerly by the weekend. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...LaPlante NEAR TERM...Garnet SHORT TERM...Greenawalt LONG TERM...Kubina AVIATION...Saunders MARINE...Greenawalt
Area Forecast Discussion
National Weather Service Duluth MN
957 PM CDT Sun Aug 26 2018 .UPDATE... Issued at 955 PM CDT Sun Aug 26 2018 A severe thunderstorm watch has been issued and is in effect until 4 am CDT for Koochiching, Itasca, and Cass counties. UPDATE Issued at 710 PM CDT Sun Aug 26 2018 Updated aviation discussion below. && .SHORT TERM...(through Tonight) Issued at 327 PM CDT Sun Aug 26 2018 The focus is on the potential for thunderstorms and severe weather through tonight. There is a complex scenario today from the Northern Plains to western Great Lakes which could lead to multiple rounds of thunderstorms across the Northland through tonight. The complexity is contributing to uncertainty in the forecast. As of the middle of the afternoon, there as an area of low pressure in central South Dakota. A warm front extended from the low across southern Minnesota into southern Wisconsin. A stationary front extended from eastern South Dakota to northwest and north-central Minnesota. Shortwaves were lifting northeast through the region, including one across northeast Minnesota, and another near west-central Wisconsin. These shortwaves were triggering areas of thunderstorms. The Northland will, at the least, be affected by the shortwaves lifting through the region, and continue to see showers and storms across northeast Minnesota and parts of northwest Wisconsin through this afternoon. There is then a good chance of additional thunderstorm development late this afternoon and this evening. These storms would begin in areas of northwest Wisconsin to central Minnesota and spread north and will be in relation to a surge of humid air with the lifting warm front. The latest HRRR and RAP runs have suggested the storms might not develop until nearly as far north as the Grand Rapids to Duluth to Ashland area. Wherever these storms develop, strong to severe thunderstorms are possible. There will be an environment of up to 3000 J/kg of MUCAPE, 30 to 40 knots of deep layer wind shear, and precipitable water values of 1.5 to 2 inches. The primary concern will be large hail, but strong wind gusts and heavy downpours are possible. The flooding threat is limited because of the relatively dry soils and progressive nature of the storms lifting northward. However, ponding is possible in more urban areas. Another round of storms is possible late this evening into the wee hours of the morning. These storms will be related to an approaching trough from the west. The latest convective-allowing models suggesting a storms that develop earlier in the evening in eastern North Dakota and northwest Minnesota could evolve into a north-south orientated line of storms by late this evening that would move into the Northland from the west. These storms could be severe, with large hail and damaging winds. Brief heavy rain is also possible. There be an environment of up to 3000 J/kg of MUCAPE, 40 to 55 knots of deep layer wind shear, and precipitable water values of about 1.5 inches. Another round of storms is possible near Price County late tonight. These storms will be tied to another shortwave lifting northeast Isolated thunderstorms are possible over western Lake Superior through this evening. through the area. The environment will not favor severe weather, but some of the storms could be strong with small hail, gusty winds, and very heavy rainfall rates. There will be about 2000 J/kg of MUCAPE, 25 to 30 knots of deep layer wind shear, and precipitable water values of 2 inches. If the storms produce heavy rain over areas that get heavy rain this afternoon, there could be a heightened risk of flooding. Overall, it will a warm and humid night with chances of thunderstorms. Overnight lows will be in the middle 60s. Areas of fog are likely by dawn. .LONG TERM...(Monday through Sunday) Issued at 327 PM CDT Sun Aug 26 2018 A shortwave will lift northeastward into Ontario Monday morning, while a ridge briefly builds in. This will bring an end to showers and thunderstorms across much of the Northland Monday morning. This will be brief as a trough slowly digs across the Northern Plains into northern Minnesota on Tuesday. At the surface a quasi- stationary front will be the focus for thunderstorm development. MLCAPE values will increase to 1000-3000 J/kg and 0-6 km bulk shear to 40-50 knots. This environment will be conducive for organized convection with strong to severe storms possible. Precipitable water values will increase to 1.5 to 2.0 inches, which is at or above the 90th percentile for MPX sounding climatology. The majority of the 12Z CAM guidance suggests that an MCS will develop across central Minnesota and propagate eastward through northwest Wisconsin. In this environment expect the main threats of damaging wind gusts and heavy rain which may lead to flash flooding. Expect the heaviest rainfall across northwest Wisconsin where 1 to 2+ inches is possible. Despite the high agreement with CAMS there is uncertainty with the evolution as the convection that occurs late this afternoon and overnight will impact how things develop on Monday. Expect the heaviest rainfall late Monday with the highest totals over northwest Wisconsin. Highs on Monday range from the upper 60s to the mid 80s. The trough will continue lifting northeastward into Ontario on Tuesday. This will gradually move the stationary/cold front eastward through Wisconsin. In its wake a mid-level ridge will build in from the Northern Plains. This will gradually end precipitation from west to east. Flow aloft will become northwesterly and advect in cooler air. High temperatures on Tuesday range from the mid 50s over the Minnesota Arrowhead, to the low 70s across southern portions of northwest Wisconsin. A shortwave will move across the High Plains into the Mid Mississippi River Valley on Wednesday bringing chances of scattered shower. There is some uncertainty at this point as GFS has high pressure building in overhead, while a ECMWF/GEM keep the frontal boundary lingering across northwest Wisconsin. There is more agreement in shower/storm chances late in the week heading into next weekend. A trough will dig in from the Pacific Northwest into central portions of Canada. This will bring southwesterly return flow to the Upper Mississippi River Valley. Expect temperatures to warm up to the low to mid 70s on Friday/Saturday with shower and thunderstorms being possible. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 710 PM CDT Sun Aug 26 2018 A complicated setup befalls the Northland tonight. Storms forming along a warm front moving northward through the region should linger on and dissipate around midnight. Another round of storms coming from the west will affect most sites around the late night and early evening hours. MVFR or lower conditions are possible with both rounds of storms. With the recent rainfall and winds becoming relatively light overnight, patchy fog may develop. The uncertainty with fog development lies in whether skies will clear enough before and after the second round of storms. For now, did not feel confident to put fog in the TAFs. VFR conditions return late Monday morning. Another round of showers and storms come through Monday afternoon/evening. && .PRELIMINARY POINT TEMPS/POPS... DLH 64 76 56 60 / 50 40 50 40 INL 63 65 47 61 / 90 20 50 40 BRD 68 76 56 65 / 30 50 50 30 HYR 67 83 60 68 / 40 70 80 40 ASX 65 83 59 63 / 90 60 60 40 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && $$ UPDATE...Wolfe SHORT TERM...G2 LONG TERM...WL AVIATION...KC
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
252 PM PDT Sun Aug 26 2018 .SYNOPSIS...Near normal temperatures are expected to continue through the upcoming week as a series of upper-level disturbances impact the West Coast. Additionally, areas of smoke and haze will linger across some of the area for the next couple of days. && .DISCUSSION...Upper-level troughiness is expected to continue through early this week, with another upper-level disturbance forecast to dig across the Pacific Northwest and northern California late in the work week. These features will aid in keeping temperatures near normal across northwestern California through next weekend. No rain is expected across the forecast area over the next seven days, though the GFS does portray showers over eastern Del Norte county, but confidence is low. Sunday afternoon visible satellite imagery shows marine stratus has dissipated once again over most of the coastal waters. The lone exception today is south of the Cape Mendocino, which continues to see stratus offshore and along the immediate coast. Smoke looks to be less widespread than yesterday, though wildfire smoke from southwestern Oregon continues to drift southward. Recent HRRR smoke guidance indicates smoke may continue to pass across coastal waters and the immediate coast as the area drifts southward. Sunnier conditions are expected this evening and Monday evening, though some smoke layers may linger. && .AVIATION ...Offshore flow helped to keep KCEC free from stratus development early this morning while coastal locations from the Humboldt Bay area southward to Point Arena experienced MVFR to IFR conditions today. KACV will experience VFR into the early evening as daytime mixing maintains mostly clear skies. Otherwise everywhere to the south will be stuck under the clouds with brief scattering possible late this afternoon. The forecast through tomorrow afternoon will be close to persistence with stratus returning to coastal airfields except for KCEC due to dry easterly flow. Otherwise expect mostly VFR across the interior. /KML && .MARINE...Fresh northerly winds will continue across the outer coastal waters this afternoon and begin to diminish late Monday as a weak front causes the pressure gradient to relax. Winds will overall be lighter nearshore but gusts near 30 kt will be possible around Point Saint George and Cape Mendocino through Monday afternoon. Additionally, eddies in the wind flow will bring south winds to parts of the Mendocino and Humboldt county coasts. Light to moderate winds will then persist through most of the week ahead with more widespread south winds forecast to develop off of the Mendocino Coast on Tuesday. Models indicate a return of fresh northerly winds by next weekend but there is still some uncertainty at this time. Otherwise, steep seas will gradually subside this week and west- northwesterly swell will impact the coastal waters. Expect the sea state to fall around 5 ft later in the work week. The small craft advisories remain in effect through Monday afternoon. /KML && .FIRE WEATHER...Locally gusty east to northeast winds will be possible tonight and Monday evening/night across the ridge tops of interior Del Norte county as a weak upper-level trough continues to move out of the western U.S. RH recoveries have been pretty good the past few days and this trend is expected to continue through Monday. Otherwise, onshore flow will yield near normal temperatures area-wide through next week. && .EKA WATCHES/WARNINGS/ADVISORIES... CA...None. NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until noon PDT Monday for PZZ450. Small Craft Advisory until 9 PM PDT Monday for PZZ470-475. && $$ Visit us at http://www.weather.gov/eureka Follow us on Facebook and Twitter at: http://www.facebook.com/NWSEureka http://www.twitter.com/nwseureka For forecast zone information see the forecast zone map online: http://www.weather.gov/eureka/zonemap.png
Area Forecast Discussion
National Weather Service Grand Forks ND
1017 PM CDT Sun Aug 26 2018 .UPDATE... Issued at 1016 PM CDT Sun Aug 26 2018 With a shortwave ejecting out into the Northern Plains and the low level jet starting to ramp up, convection has been increasing in coverage across much of the central and northern CWA. Storms have been moving into the southern counties also but are more isolated in coverage. MU CAPE is ranging from near 1500 J/kg in the north to 3000 in the south, and deep layer bulk shear is over 50 kts. A severe thunderstorm watch has been issued to include the counties to the north and east of the existing tornado watch as the storms move eastward. CAM models have not been very consistent with where they are taking the strongest cells, but have a general idea of quite a bit of rain in the north and more hit and miss in the south. Adjusted POPs accordingly. && .SHORT TERM...(This evening through Monday) Issued at 247 PM CDT Sun Aug 26 2018 Watching ongoing convection, so will keep the discussion brief. Seeing intensifying activity over far southeast ND right now, with satellite imagery correlating the growing clouds. SPC put out a mesoscale discussion a short while ago, talking about a potential watch for the southern third of our FA. This growing convection may push this watch into a quick reality. Latest HRRR runs have been showing other activity firing over the Red River Valley by 8 to 9 pm, and lasting until just past midnight. They no longer show any activity pushing in from western ND. So will see how things play out tonight. .LONG TERM...(Monday night through Sunday) Issued at 247 PM CDT Sun Aug 26 2018 Rain chances return Monday night into early Tuesday across the area as a shortwave trough moves into the region and a low pressure system skirts by to the south through the Central Plains. With little instability present on the cool side of this system, suspect this will be mainly shower activity with perhaps some embedded thunder. For Tuesday through Thursday, expect quiet and dry weather. Temperatures will be notably cooler Tuesday and Wednesday as the upper trough axis swings through the Plains and dry northwest flow aloft develops. A warming trend develops from Wednesday to Friday in warm air advection ahead of a system moving through the Canadian Plains. After a breezy day Thursday amidst pressure gradient winds, chances for showers and thunderstorms develop Thursday night through Friday night as a shortwave trough aloft and surface front pass through the Northern Plains. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 642 PM CDT Sun Aug 26 2018 Still tried to hit the 8 pm to just past midnight time frame as the prime hours for storm development. Not much happening right now, but expect storms to blossom over the area in the next couple of hours. Pretty hard to say exactly where and when, so all TAF sites still have a chance. Activity should begin to wane a few hours after midnight. These storms could also drop some heavy rain at times. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...JR SHORT TERM...Godon LONG TERM...BP AVIATION...Godon
Area Forecast Discussion
National Weather Service Hastings NE
632 PM CDT Sun Aug 26 2018 .SHORT TERM...(This evening through Monday) Issued at 312 PM CDT Sun Aug 26 2018 Aloft: WV imagery/RAP dynamic tropopause analyses/aircraft wind data showed a large subtropical high over TX/OK. A longwave trof extended from the Nrn Rckys down to Cntrl CA. This config has resulted in SW flow over the Cntrl Plns. A weak/subtle shortwave trof was currently over Neb/KS and was responsible for the spotty light shwrs this AM. This trof will exit E of the CWA this eve. Cyclonic flow will remain over the rgn in its wake thru tomorrow as the Nrn Rckys trof deepens. Surface: The CWA was in the warm sector. High pres was over the SE USA while a cool front extended from Hudson Bay thru SD and into the Nrn Rckys. Much of this front was stationary. Low pres was along the front over SD. This low will strengthen and rapidly move into SW Ontario tonight. With the SW flow aloft...the front will struggle to move S but it is fcst to sag into Nrn Neb tomorrow. Rest of this afternoon: P-M/cldy. Lowered high temps where cloud cvr has been most persistent. Some HREF members suggest a couple tstms could fire over the SE fringe of the CWA (Osborne-Hebron-York). HRRR and the HRRRX ensemble say no...but have a low 20% POP to cover this potential. SREF MLCAPE is fcst 1500-2500 J/kg with 0-6 km shear around 30 kt. So a stg-svr tstm can`t be ruled out if something develops. Tonight: if any tstms dvlp far SE...they will exit the CWA early. Should see a temporary decrease in clds as the trof departs and subsidence moves in...but then an increase in clds from distant tstms over the high plns. There is a lot of uncertainty but have introduced a low 20% POP W of Hwy 183 just in case some dying remnants of high plns tstms move in from the W after 03Z. HREF members suggest they will die before reaching the CWA...but the HRRR and a minority of the HRRRX ensemble maintain a little tstm activity could survive and move in. There is a very low chance a few high-based tstms could also form after midnight well N and W of the Tri-Cities. Overall...another very warm and muggy night. Winds will remain brzy over the SE 1/2 of the CWA. Mon: Could see a few high-based tstms before noon well N and W of the Tri-Cities. Decreasing clds and hot with widespread 90s. Would not be surprised to see 100F in a couple spots from Furnas into Phillips counties where the air will be driest. Even if the temp doesn`t reach 100F...there will be a few spots where the Heat Index reaches 100-103F over the SE 1/2 of the CWA. Mercifully... that area will be the breeziest. .LONG TERM...(Monday night through Sunday) Issued at 312 PM CDT Sun Aug 26 2018 Aloft: Looking at spaghetti plots of the last 2 runs of the EC/GFS/GEM/UKMET...the longwaves trof over the NW USA trof will advance across the Nrn/Cntrl Plns Tue followed by rising heights Wed with zonal flow continuing into Thu. The longwave trof over the NW USA will reload during that time and it now looks like it will progress thru the Nrn/Cntrl Plns Fri...somewhat ironically like the 12Z/Sat GFS which I dismissed as an outlier. A lot of spread dvlps Fri which is not surprising given that a blocking subtropical high (currently btwn AK and HI) will persist thru the wk. We should see a trof deepen over the Wrn USA with a ridge in the E. Amplification is fcst...but how the mdls are treating shortwave activity circulating around the top of the ridge results in tremendous spread within the Wrn trof next wknd into the 1st wk of Sep. Surface: The cool front will finally drop S thru the CWA Mon night into Tue. Cool high pres will cross the rgn Wed with return flow dvlpg. Deep low pres will swing thru SW-Cntrl Canada Thu. This will induce warm frontogenesis over Neb/KS and this front is fcst to move thru Thu night. Warm sector Fri with passage of a cool front Fri night. Thereafter there`s just too much uncertainty to provide any other specifics. We`ll have to wait and see. Temps: Breezy and much cooler Tue in CAA. Wed temps will be cooler than normal as well. Then returning to near normal Thu. Above normal Fri in the warm sector...then back to near normal Sat-Sun behind the cool front. Rain: No significant widespread rain is currently envisioned. As is typical of summer...most of the time will be dry. Can`t rule out a few isolated tstms in vicinity of the cool front Mon night into Tue night...espcly as the RRQ of a strong 130 kt jet streak moved thru ahead of the upr trof. Best chance will be S and E of the Tri- Cities where instability will exist. The next modest chance for a few tstms will be Thu night as the nose of the low-lvl jet impinges upon the warm front. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday) Issued at 630 PM CDT Sun Aug 26 2018 A few thunderstorms to the southwest of the KGRI terminal area and could briefly affect the terminal in the next couple of hours. They should be dissipating as the sun goes down. Ceilings should remain VFR through the period. There could be some low level wind shear late tonight then winds increase late tonight and Monday during the day. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...Kelley LONG TERM...Kelley AVIATION...JCB
Area Forecast Discussion
National Weather Service Goodland KS
450 PM MDT Sun Aug 26 2018 .SHORT TERM...(This evening through Wednesday) Issued at 328 PM MDT Sun Aug 26 2018 Forecast concerns will be chance of precipitation tonight along with Monday night into Tuesday night, high temperatures Monday and Tuesday, Fire weather on Monday, and the winds with the passage of the cold front. Satellite showing an amplified flow from the Pacific into western North America. This flow flattens out and is more progressive over the central and eastern portion of the country. Rather strong and cold upper trough moving through southwest Canada and northwest portion of the country. Satellite and upper air analysis show a more moist air mass through mid levels than compared to 24 hours ago. For Tonight/Monday...Right rear quadrant of the jet is near or over the far western portion of the area later this afternoon/early this evening and then only moves a little further east through the rest of the night. A couple of shortwave troughs move through during the evening and overnight hours. There now appears to be some surface covergence out west with a new surface trough. Even though the instability is less further west, models appear to be latching onto all the above and generating some thunderstorms across the area through the night. The Rap is the most aggressive with this. Considering that there is development out there already will follow the above trend. At this time, the lift and greater instability to our east, is just to the east of our forecast area. Per all the above am keeping the thunderstorms out of the eastern portion of the area. Above mentioned right rear quadrant is slower/further west than what was shown yesterday. It will continue to affect the southeast half through the morning hours. There may be some lingering lift and rainfall going on early in the morning so will keep a slight chance there. After any morning precipitation clearing should be rapid and expect plenty of sunshine. There is a deep layer of dry air and downslope winds. Trend in the 850 mb temperatures, 2 meter, and Mos is to maintain or warm the air mass even more than today. That makes sense with less cloud cover and more downslope. So raised high temperatures in according with 850 mb temperature bias and warmer 2 meter and Mos. This means temperatures will be near 100 in a lot of places tomorrow. Refer to the fire weather section for discussion on this. Monday night into Tuesday night...Will get into more detail on the front below, but the front looks to be arriving later. Overnight shift was thinking that some thunderstorms could develop along it. 700 mb temperatures ahead of the front would indicate air mass ahead of it will be capped. Area is in subsidence from exiting jet. Forecast soundings are also showing an extremely deep dry air mass in place ahead of the front. Due to all that and collaborating, have kept Monday night dry. Models are now generating a lot of post frontal precipitation. However, models are differing on how deep the moisture is. Forecast builder now has pops in Tuesday and especially Tuesday night. A complicated jet structure moving across and showing some differences in how they want to move this across. First jet segment/right rear quadrant moves across the area Tuesday afternoon with a second segment and right rear quadrant moving across during the evening and overnight hours. Models showing a strong baroclinic zone at 700 mb beneath the jet lift. Frontogenesis forecasts show weak to moderate forcing moving across the area during this time. Midlevel theta-e lapse rates near to slightly below zero so there should be a good response to the lift. Models also showing some elevated Cape. May end up being more embedded thunderstorms in the rain showers but decided not to get too cute with this. So like the pops that are in there Tuesday and especially Tuesday night. Potential is there for pops to be expanded in time and space on Tuesday. Cold front looks to be a little slower in arriving and looks now to not move into the area until after midnight. It looks to be through the northwest half by late in the night and through the entire area by late morning. Very tight pressure gradient and 3 to 6 hour pressure rises of 5 to 10 mb would indicate windy conditions to follow behind the front. Per that and collaboration with neighbors, loaded in Consmos for the winds for this period. There is about a 20 degree difference in the high temperature forecasts for Tuesday. The Nam/Met is by far the most aggressive with the temperatures which they have mostly in the 60s. This is due to a blanket of stratus and any ongoing precipitation. Believe the Nam is on the right track, and with the last major cool down it did best. I did cool down the blend temperatures to near the mid point of the extremes from the Mos and 2 meter guidance. However this may need to be reduced much more. Wednesday...Precipitation looks to be done. Temperatures remain cool, and depending on how Tuesday works out, still look reasonable. .LONG TERM...(Wednesday night through Sunday) Issued at 156 PM MDT Sun Aug 26 2018 High pressure over the southwest U.S. and upper level zonal flow dominate through Friday leading to above normal temperatures. A dryline sets up along the Kansas/Colorado border Wednesday night into Thursday morning which could provide the necessary lift for the formation of thunderstorms Wednesday night into Thursday morning. The dryline then moves east by Friday taking above normal precipitable water values with it. The lack of decent PWAT values should hinder any chances for rain until moisture returns to the region Saturday night. The base of a trough moves across the central Plains Friday night bringing a surface low that will lead to cooler temperatures Saturday. A ridge moves over the Plains Saturday with the high pressure centered over the far southwest U.S. An incoming trough over most of the western U.S. pushes the ridge out quickly leading to only a slight warming of temperatures Sunday. The east side of the incoming trough extends into central Kansas leading to precipitation chances Sunday evening. The main takeaways are that the heat returns Thursday with some cooling over the weekend and mostly dry conditions are expected throughout most of this forecast period. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 445 PM MDT Sun Aug 26 2018 KGLD, vfr conditions expected through the period. Some disagreement on the wind forecast from taf issuance through sunrise Monday morning but general idea is for a south wind 10kts or less with some erratic direction changes dependent on possible convection near or over the terminal. At this point precipitation coverage is very spotty and will leave out of the forecast but will amend should an impact be expected. Main threat will be gusty outflow winds. For the day Monday will see southwest winds veer to the west 10kts or less then back to the southwest and increase a bit with some gusts toward 20kts or so ahead of an approaching weather system from the northwest. KMCK, vfr conditions expected through the period. Am expecting south winds under 10kts through 11z with southwest then west winds around 6kts or so through 20z. After 21z winds back to the southwest and approach 10kts with perhaps a few gusts as pressure falls increase ahead of an approaching weather system from the northwest. Similar to KGLD will leave out any mention of showers and/or thunderstorms for now as coverage is very spotty. Amendments will be issued should an impact to the terminal be expected. Gusty outflow winds will be the primary concern. && .FIRE WEATHER... Issued at 328 PM MDT Sun Aug 26 2018 For Monday...Air mass looks a little drier than yesterday. Relative humidities are 16 to 20 percent across all but the far eastern portion of the area. The lowest humidities are along and west of the Colorado border. Lapse rates look good and should mix that drier air down and also some stronger winds. Per collaboration with neighbors, I used Consmos, and still did not get winds of 25 mph or greater where the lowest relative humidities will be. At this time where the strongest winds will be is where the highest humidities will be. So will keep the previous of only elevated fire weather danger. SPC forecast reflects that as well. If however mixing will go even higher than what I think, then the winds and humidities may need to be lowered even more. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...NEWMAN AVIATION...99 FIRE WEATHER...BULLER
Area Forecast Discussion
National Weather Service Grand Rapids MI
754 PM EDT Sun Aug 26 2018 LATEST UPDATE... Update/Aviation .SYNOPSIS... Issued at 313 PM EDT Sun Aug 26 2018 Several rounds of nocturnal thunderstorms are possible starting tonight lasting through Wednesday morning. Areas north of I-96 have the best chance of seeing thunderstorms tonight and Monday night with area wide activity possible Tuesday night and into Wednesday. While localized severe weather is possible each night (damaging wind gusts to 60 mph and 1" hail), very heavy rainfall and localized flooding are the greatest concerns. Dry conditions are then expected by the end of the workweek. && .UPDATE... Issued at 754 PM EDT Sun Aug 26 2018 I have increased the POP and QPF over our northern two rows of counties tonight since run after run of the HRRR continues to show an area of 2 to 4" of rain near and north of Route 10 tonight. There is good 1000/850 moisture transport into that area and 1000/700 thickness pattern supports this idea. I am concerned about that much rain but it has been dry in that area so at this point I am not planning on issuing a flood advisory. Still this will have to be watched as this area may see storm after storm go over the same area. Areas near and south of I-96 should for the most part stay dry tonight. I am planning on letting the marine fog advisory end as scheduled at 8 pm. Seems the fog is lifting out of that area. && .SHORT TERM...(This evening through Tuesday night) Issued at 313 PM EDT Sun Aug 26 2018 As a shortwave trough embedded within broad southwesterly flow aloft moves northeast into the Great Lakes, all eyes will be on convective trends this afternoon across portions of Iowa, Minnesota, Wisconsin, and perhaps as far south as northern Illinois. Several clusters are already ongoing as of this writing but everything so far has been relatively unorganized. Surprisingly, the 12Z suite of numerical model guidance (e.g. HREF ensemble, SREF [derivative of the NAM], various WRFs and iterations of the HRRR, etc.) all agree that whatever develops upstream will move into northern Lower Michigan overnight, specifically north of a line from Stony Lake to Mount Pleasant. Frankly I have no reason to disagree. However, a slight shift south is definitely in the realm of possibility. So, we`ll say areas north of I-96 have the best shot of seeing activity tonight. Forecast MUCAPE >2000 J/kg and 0-6 km bulk shear suggests that the storms will become increasingly organized upstream of our area this evening with an east/northeastward propagation (e.g. 0-1 km shear vectors will be orientated east/northeast). The linear nature of expected convection suggests that strong to locally severe winds are possible with a lesser threat of hail in individual "pulsey" cores. If the clusters become somewhat staggered--that is, one leads the pack--the interaction of the expected orientation and magnitude of the low- level jet overnight with a potentially west- to-east orientated outflow boundary will promote rearward off- boundary development (e.g. training convection; see Peters and Schumacher [2014] in MWR Vol. 142). Interestingly several numerical models suggest such a scenario with a west-to-east swath of very heavy rainfall (2-4"+) by midday Monday. In fact, the HREF 24-hr ensemble localized probability-matched mean rainfall shows a swath of 2-3" across northern Lower Michigan tonight, demonstrating the agreement among various CAMS in the placement and occurrence of heavy rain. So, we have high confidence that there will be a narrow swath of very heavy rain tonight somewhere in lower Michigan most likely north of a line from Stony Lake to Mount Pleasant. Elsewhere across lower Michigan, dry conditions are expected overnight but patchy fog is possible. Surface winds at/above 5 kts overnight should limit both the spatial extent and intensity of the fog compared to this morning. By late Monday morning, the expectation is for any remaining convection to wane as the low-level jet weakens and veers west. A period of dry weather is then expected in lower Michigan before we do it all over again Monday night and into Tuesday. A similar regime appears possible with one or two clusters of strong to severe convection propagating into lower Michigan aided by a southerly low- level jet. There does seem to be a signal that the convection will be decaying this time around, but again areas north of I-96 (and especially north of a line from Stony lake to Mount Pleasant) are favored for repeated activity. Depending on how much rain falls tonight, localized flooding may become an issue north of I-96 especially if the same areas are hit (see the hydrology discussion below). Then, we get to do it -again- on Tuesday and Tuesday night. However, development Tuesday seems like it`ll be tied to a southward-drifting outflow boundary/effective warm front originating from activity from the nights before. Indeed, development may occur right overhead Tuesday afternoon/evening with both severe weather and heavy rainfall possible. We`ll leave it at that for now. So, to summarize, repeated rounds of storms are expected starting tonight and lasting through early Wednesday favoring areas north of I-96 through early Tuesday. While locally strong winds and hail are possible, the main threat is heavy rainfall and flooding where the convective complexes train. .LONG TERM...(Wednesday through Sunday) Issued at 313 PM EDT Sun Aug 26 2018 Model guidance has started to hint at the development of a low pressure system on Wednesday along the effective warm front draped along our area. Given the dependency on convection basically tonight through Wednesday and associated uncertainties, I have very low confidence that a low will actually develop. However, it is still worth noting that Wednesday may be wet. Thereafter, a high pressure system is expected to slide into the Great Lakes by Thursday and last into the first portion of the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 754 PM EDT Sun Aug 26 2018 Currently all TAF sites are VFR and more than likely will stay so till at least 03z or so. There is an area of convection over eastern WI moving toward Lake Michigan as I write this. All indications are the storms will mostly stay north of our TAF sites. However I am concerned about MKG so I did bring the storms into that area in the 04z to 08z time frame. It is possible the convection from the WI line would get there sooner, so I will continue to watch this. Otherwise it should stay largely VFR into Monday evening. Most of the convection will be north of our TAF sites through Monday evening. Low level wind shear is expected at the MKG and GRR taf sites due to the position of the mid-level jet to those TAF sites. && .MARINE... Issued at 313 PM EDT Sun Aug 26 2018 Areas of dense fog will continue this afternoon across portions of Lake Michigan. Southerly winds are then expected to increase to 20- 25 kts tonight and to 25-30 kts Monday night. A few gusts to 30 kts are possible on Monday night. Waves will accordingly increase to 3-5 ft toward daybreak tomorrow, and then 4-7 ft overnight into Tuesday. While waves will start to relax during the day on Tuesday, an increase in wave heights is possible on Wednesday in the wake of a front. All in all, very hazardous boating and swimming conditions are expected through midweek. Remember... - Stay dry when waves are high! - Stay clear of the pier (including on walkways as waves can still knock you off)! && .HYDROLOGY... Issued at 313 PM EDT Sun Aug 26 2018 A favorable pattern for heavy rainfall is setting up through Tuesday night that will likely lead to rises on area rivers and streams particularly near and north of I-96. Antecedent conditions are drier across this region (mainly near/west of US 131, where a Moderate Drought is in place) as compared to other regions across central and southern Lower Michigan. As a result, rainfall will initially get soaked into the soil pretty rapidly. However, successive rounds of primarily nocturnal convection could saturate soils enough to lead to significant rises on smaller rivers and streams. Main stem rivers like the Muskegon River have plenty of capacity for runoff at this point, with Evart currently sitting around the 20th percentile for streamflow. The Pere Marquette is currently near normal, with flows only around a foot at Scottville, which is a site that requires a significant amount of rain to flood. Similarly, the White River at Whitehall has a wide capacity to take on significant rain at this point with flows around the 55th percentile. If any of these sites get a few inches of rainfall through Monday morning and then were to get significant additional rain Monday night into Tuesday morning and beyond, it is conceivable that flooding would be a problem. Shy of this happening, the rivers will likely still rise (possibly quite a bit) but hold below flood stage. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Beach Hazards Statement from 4 AM EDT Monday through Tuesday morning for MIZ037-043-050-056-064-071. LM...Small Craft Advisory from 4 AM Monday to 8 AM EDT Tuesday for LMZ844>849. Dense Fog Advisory until 8 PM EDT this evening for LMZ846>848. && $$ UPDATE...WDM SYNOPSIS...Borchardt SHORT TERM...Borchardt LONG TERM...Borchardt AVIATION...WDM HYDROLOGY...Hoving MARINE...Borchardt
Area Forecast Discussion
National Weather Service San Francisco Bay Area
831 PM PDT Sun Aug 26 2018 .SYNOPSIS...Cooler than normal temperatures are forecast to continue, especially inland, through midweek as a trough of low pressure remains over California. A brief warming trend is possible later in the week as a weak ridge of high pressure temporarily builds over the area. && .DISCUSSION...As of 8:30 PM PDT Sunday...A slight increase in both the depth of the marine layer and strength of onshore flow was enough to bring about cooling across much of the North and East Bay today. Otherwise little change was observed. A longwave trough is currently located over the Pacific Northwest and northern Rockies. A weak shortwave embedded in the flow on the upstream side of the trough is dropping south along the coast of Oregon. The models agree that this shortwave will pinch off from the main flow and form a weak upper low near Point Arena by Tuesday morning. This is expected to result in slight deepening of an already deep marine layer. Thus, we can expect continued cooler than normal conditions across our region through midweek. The weak low is forecast to fill by Wednesday. A second weak upper low several hundred miles west of the California coast is forecast to approach the coast later in the week. As the low approaches, a shortwave ridge is forecast to develop upstream of the low and over California by late Thursday and Friday. This should result in modest warming late in the week, primarily inland. Even with this warming, temperatures are expected to remain a bit cooler than normal. Both the GFS and ECMWF forecast the upper low to track across northern California sometime around Saturday. The low may produce scattered showers over the higher mountains to our north and northeast, but dry conditions are expected to prevail across our area. The primary impact of this low will be to cool temperatures during the first part of next weekend. && .AVIATION...as of 6:38 PM PDT Sunday...It`s VFR except along the immediate coast stratus is causing areas MVFR ceilings. A general increase in stratus is forecast tonight and Monday morning due to onshore winds, and little change in depth of the marine layer is forecast for the period. Today`s 18z High-Resolution Rapid Refresh (HRRR) output indicates wildfire smoke from the Mendocino Complex remaining over the North Bay while a combination of this wildfire`s smoke and additional smoke from far northern California will spread into the Bay Area mid evening to Monday morning; however, a 4 pm report from the Farallon Islands showed good visibility at 10 miles while the 18z HRRR forecast for this location showed light amount of smoke thus the HRRR may in spots be overforecasting smoke coverage. Going back to last Tuesday evening into Wednesday lower level cool air advection within the marine layer appeared to have at least initially helped slow or limit the arrival of then forecasted surface based smoke on W-NW winds. Lower level cool air advection is forecast tonight through late Monday thus there may once again be sufficient mixing to keep surface based visibilities generally good while slant range visibilities aloft may tend to lower to moderate to poor over the Bay Area valleys above the marine temperature inversion by early Monday morning. Vicinity of KSFO...VFR, however westerly wind near 15 knots possibly ushers in a stratus cloud based MVFR ceiling tempo MVFR 04z-06z then it`s prevailing MVFR to 18z Monday. VFR returns late Monday morning through the afternoon. SFO Bridge Approach...Similar to KSFO. Slant range visibility may tend to lower to moderate to poor by early Monday morning. Monterey Bay Terminals...MVFR ceilings developing early evening, transitioning to IFR tonight. IFR mixes out by late Monday morning, VFR forecast Monday afternoon and early evening until stratus likely returns early Monday evening. Slant range visibility may become moderate Monday. && .MARINE...as of 5:00 PM PDT Sunday...Breezy conditions will continue tonight over the outer waters north of Pigeon Point as northwesterly winds prevail. Generally light northwest swell around 3 to 6 feet is expected through the forecast period. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pt Arena to Pigeon Pt 10-60 nm && $$ PUBLIC FORECAST: Dykema AVIATION: Canepa MARINE: Sims Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea