Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/12/18


Area Forecast Discussion
National Weather Service Gaylord MI
957 PM EST Sun Nov 11 2018 .UPDATE... Issued at 957 PM EST Sun Nov 11 2018 Lake effect into the tip of the mitt had consistently waned since the previous update. That is, until the last 45 minutes or so, when another (final?) shot of mid-level moisture has contributed to an uptick into Emmet Co. Suspect this will be relatively brief, as mid-level moisture will decrease as 500mb heights tick upwards ever-so-slightly overnight. Nam Bufr soundings at PLN show drying in the 5-10k ft layer overnight, and a corresponding lowering of inversion heights from 7k to 5k ft. So expect the current uptick to be relatively brief, but it is enough to warrant maintaining the current headlines over far northern lower MI. Meanwhile, sub-850mb winds have veered enough such that bands are just scraping by St Ignace and Drummond Isl. Advisories for Chip/Mack Cos were set to expire at 10pm, and have let them do so. Have also lowered Leelanau-Antrim Cos; there is little going on there now, and though activity will migrate southward with time overnight into the morning, we should be in a weakening stage by then. UPDATE Issued at 632 PM EST Sun Nov 11 2018 Continued vigorous lake enhanced bands poking into far northern lower MI have required an upgrade to a warning for Emmet Co. The central portion of Emmet, between Levering and Petoskey, will see total accums of 5-10 inches. Recent HRRR runs show nearly 0.50" of liquid QPF in this area. That is probably a little too high, which is good, as that would equate to over a foot of snow. Will be cautiously watching neighboring counties (especially Cheboygan) for any potential need for an upgrade. && .NEAR TERM...(Through Tonight) Issued at 300 PM EST Sun Nov 11 2018 ...Lake Snow Showers Through Tonight... High Impact Weather Potential: Accumulating lake snows for parts of NW lower Michigan. Pattern Synopsis/Forecast: Afternoon analysis reveals low amplitude short-wave trough advancing across northern Michigan, attending surface low is across the U.P./Lake Superior. Main QG- forcing for ascent ahead of the wave is moving out of the CWA evidenced by diminishing trend to the larger scale snowfall across the region. But SW flow enhancement continues off Lake Michigan into NW lower Michigan of course with the heaviest snows impacting the Lake Michigan shoreline from Grand Traverse Bay up through Charlevoix/Emmet and parts of Cheboygan county and eastern upper Michigan. Primary Forecast Concerns: Ongoing lake enhancement and accumulations. QG-forcing for ascent and remaining widespread snowfall ends this evening. However, low level flow veering more westerly in time and favorable lake effect parameters will continue to target areas from Leelanau county up through the tip of the mitt for a good part of the night. Plan to extend/expand advisories for Emmet/ Charlevoix Cheboygan counties through tonight and I may add Leelanau and Antrim counties back into the mix for good measure (with lake banding skirting Leelanau and heavier elements impacting Antrim county). Further north, it`s been difficult to tell exactly what`s happening today along the Lake Michigan and Huron shoreline. But have to believe that heavier convective elements are getting into the southern parts of Chip/Mack counties. Will probably just leave the advisories up there alone for now. They expire at 03Z which corresponds well with winds veering more westerly tonight. && .SHORT TERM...(Monday through Wednesday) Issued at 300 PM EST Sun Nov 11 2018 High Impact Weather Potential: Accumulating lake effect snow expected at times, primarily across WNW/NW flow snowbelts. Pattern Synopsis: Winter-like pattern continues through midweek across northern Michigan led off by a weak cold front crossing the forecast area during the day Monday, all while a storm system a storm system emerges across the southeastern tier of the CONUS and rides toward the East Coast. A well-defined shortwave will carve through the Great Lakes region on Tuesday, bringing a reinforcing shot of cold air before heights aloft slowly begin to rise through the day Wednesday...at least briefly. Primary Forecast Concerns/Challenges: Lake effect snow potential through the forecast period. Overall large scale pattern will remain supportive of continued lake effect snow chances downwind of Lake Michigan and Lake Superior Monday through at least Tuesday night. Aforementioned cold front crossing the region during the day Monday along with renewed troughing overhead as shortwave troughing digs into the region Monday night-Tuesday will combine to deliver continued cold air aloft...evident by H8 temps falling from roughly -10 C Monday morning to -16 C. Plenty of lake induced instability will result as delta Ts range from 15-20 C; however, as was alluded to by the prior forecaster, subsidence inversion heights through the period generally varying from 4-6 kft and moisture limited to sub 800 mb should limit the overall coverage and intensity of snow showers. Steering flow varying from WNW to NW should focus the most persistent snows across the typical areas of northern Chippewa/northwest Mackinac counties and along and west of I-75 across parts of northwest lower. Tuesday will likely be the day to feature more robust snow shower activity as synoptic support increases from the aforementioned shortwave sliding across the region overhead. In terms of snowfall amounts, generally an inch or less during the day Monday, and 1-2" in any 12-hour block of time Monday night through Tuesday night at any given location with the WNW/NW flow snowbelts. Lake effect chances will gradually diminish Tuesday night into Wednesday as heights begin to rise and low-mid level warm air advection takes over. Below normal temperatures continue through the period with the coolest day expected on Tuesday as high temperatures top out in the mid-upper 20s for most areas...perhaps tagging 30 degrees nearest the Great Lakes shorelines. .LONG TERM...(Wednesday night through Sunday) Issued at 300 PM EST Sun Nov 11 2018 High Impact Weather Potential: Additional accumulating snow possible Friday through the remainder of next weekend. Rather tranquil conditions expected Wednesday night through Thursday night across northern Michigan; however, a potent clipper system and attendant cold front is expected to sweep across the region on Friday. This is expected to lead to more accumulating snow chances across parts of northern Michigan through the remainder of next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 632 PM EST Sun Nov 11 2018 IFR at PLN tonight. Otherwise MVFR to VFR. Lake enhanced snow continues in northern MI. This is light is most places, but far northern lower MI is seeing more vigorous snow showers. PLN had miserable conditions this afternoon; those have improved somewhat as the better banding has drifted south. Still expect IFR conditions in snow tonight at PLN, and would not preclude occasional LIFR. Elsewhere, VFR to MVFR conditions will prevail in light snow and with a lake-induced stratocu deck. Light winds tonight, a w to nw breeze Monday. && .MARINE... Issued at 300 PM EST Sun Nov 11 2018 Southwest winds have been a little gusty today but largely short of small craft advisory criteria. Have already trimmed out the Lake Michigan nearshore zones and the Lake Huron zones will end at 6 pm this evening. Winds gradually veer into the NW tonight through Monday. But I do not anticipate any marine headlines for the next few days. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY until 5 AM EST Monday for MIZ017-019. WINTER STORM WARNING until 5 AM EST Monday for MIZ016. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...JZ NEAR TERM...BA SHORT TERM...MG LONG TERM...MG AVIATION...JZ MARINE...BA
Area Forecast Discussion
National Weather Service Cheyenne WY
422 PM MST Sun Nov 11 2018 .SHORT TERM...(This evening through Monday night) Issued at 235 PM MST Sun Nov 11 2018 Water vapor loop depicted a trough axis from south central Canada southwestward through the central Rockies. A shortwave was moving from south central MT into northern WY. Most of the snow shower activity over southeast WY was decreasing in coverage and intensity, with redevelopment from northern WY into western SD. The Winter Weather Advisory was cancelled shortly before 2 PM as WYDOT webcams showed improving road conditions along the I-80 corridor from Cheyenne to Arlington/Elk Mountain. Temperatures ranged from the lower 20s to mid 30s and winds were northerly 5-15 mph. Models/ensembles are in good agreement progging the shortwave to the north to quickly dive south across WY into CO tonight and early Monday. Only minor snow accumulations, an inch or less, are forecast with drier air aloft as the shortwave passes overnight. The light snow will end by Monday morning, with clearing skies and cold temperatures Monday afternoon as 700mb temperatures hover around -15C. After lows tonight in the single digits and lower teens, lows Monday night will moderate into the teens. .LONG TERM...(Tuesday through Sunday) Issued at 235 PM MST Sun Nov 11 2018 A trend toward warmer and drier conditions can be expected through the extended forecast period, as large scale upper ridging becomes established over much of the western CONUS. H7 temperatures return to around 0 deg C by Wednesday, suggesting the potential for highs in the 50s and lower 60s across the Plains. The chances for rain & snow will be low through the period w/ the lack of any substantial weather system. We may be on the very fringe of a more active flow pattern by Thursday and Friday as a clipper system tracks over the Northern Plains, but moisture appears very limited at this time. Cooler than average temperatures Friday and Saturday will moderate back to above normal Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 419 PM MST Sun Nov 11 2018 Have a secondary cold front moving into the area from the north this evening. There are indications that our southeast Wyoming airports could see lower ceilings. Concentrated on KCYS and KLAR for these lowering conditions as guidance shows this is where the snow is going to develop. HRRR guidance hinting at IFR/LIFR conditions at these two airfields as well. As front drops south, MVFR conditions expected at out Panhandle airports through sunrise. && .FIRE WEATHER... Issued at 230 PM MST Sun Nov 11 2018 Periods of light snow will persist through tonight with minor accumulations. Cold temperatures will continue through Monday night, followed by dry and milder conditions Tuesday and Wednesday. Fire weather concerns will be minimal due to non- critical winds and humidities. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MAJ LONG TERM...MAJ/CLH AVIATION...GCC FIRE WEATHER...MAJ
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
1002 PM CST Sun Nov 11 2018 .UPDATE... Light to moderate showers will continue to affect areas along and east of Highway 281, especially the Hill Country and the far southeast counties of our area tonight. Latest HRRR model run suggests for the shower activity to diminish significantly overnight into Monday morning. Not buying into this solution just yet with a cold front approaching from the north and a coastal low nearing the mid to upper Texas coast. Therefore, we will keep chances for rain ranging from 50 to 80 percent for areas along and east of Highway 281 through Monday morning. The cold front is expected to move across South Central Texas Monday morning with showers mainly affecting the Hill Country and southeastern counties. In the wake of the cold front, expect breezy to windy conditions and gusts up to 40 mph in the afternoon into the evening hours. A wind advisory is likely to be issued overnight or Monday morning if models continue to suggest elevated wind values. It is also likely that max temps occur before noon Monday as temps begin to drop in the afternoon and evening. By 8 PM, some areas across the Hill Country are expected to get freezing temps. The freezing temps will continue to spread south into the escarpment area through Tuesday morning. A Freeze Warning is in effect from 8 PM to 9 AM Tuesday for areas west of Interstate 35 and north of Highway 90. Another cold night is expect Tuesday night into Wednesday morning with a widespread freeze for all of South Central Texas. Dry weather conditions expected Tuesday into Friday with a warm up middle to the latter part of the week with highs in the mid 60s Friday. && .PREV DISCUSSION... /ISSUED 607 PM CST Sun Nov 11 2018/ AVIATION.../00Z TAFS/ Widespread light rain and drizzle will continue to move over most of South Central TX with only the DRT area not seeing radar echoes. There could be a brief shot of drizzle or a shower at DRT, but will wait and adjust as needed given not much attention given to that area by the mesoscale models. Will keep the eastern TAFs simple as prevailing ifr, but there could be brief dips to lifr from both lowered cigs and also from brief heavy downpours that might lower vsby to below 1 mile. A short period of lifr is included as a strong cold front approaches the I-35 corridor, and a boost in rainfall rates near the front could provide the more likely limitation. Once the front arrives, between 13Z and 17Z, strong winds should mix out the low level cigs to mvfr levels and eventually vfr several hours later. PREV DISCUSSION... /ISSUED 242 PM CST Sun Nov 11 2018/ SHORT TERM (Tonight through Monday Night)... Water vapor imagery shows a deepening trough, currently digging into the lower desert southwest. Coastal low off the middle Texas coast coupled with an increasing low-level jet is generating showers in our eastern counties. These showers could strengthen to thunderstorms as instability increases and becomes more widespread. Rain chances continue into Monday as the strong cold front associated with the trough pushes down into south central Texas with strong wind and very cold temperatures behind it. No frozen precipitation is expected behind this front as the moisture is not deep enough. Most of the Hill Country will see below freezing temperatures Monday night into Tuesday morning as the rest of the areas will be either at or just above. LONG TERM (Tuesday through Sunday)... As the trough axis moves through skies will clear amplifying radiational cooling. Tuesday night into Wednesday morning will be the coldest night where freezing temperatures reach all the way down to the coastal plains. Please remember to bring your pets indoors. This cold dry airmass will stay in place through the week with only slight modification later in the week as a slow warming trend begins. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 48 52 33 47 29 / 70 60 10 10 10 Austin Bergstrom Intl Airport 48 52 34 47 27 / 70 50 10 10 10 New Braunfels Muni Airport 50 54 33 49 27 / 60 50 10 10 10 Burnet Muni Airport 46 48 29 46 26 / 70 50 10 10 - Del Rio Intl Airport 53 57 35 52 29 / 20 10 10 10 - Georgetown Muni Airport 47 49 31 46 27 / 70 60 10 10 - Hondo Muni Airport 52 62 33 52 26 / 40 30 10 10 - San Marcos Muni Airport 49 54 34 47 27 / 60 50 10 10 10 La Grange - Fayette Regional 49 53 34 47 28 / 70 60 20 10 - San Antonio Intl Airport 51 57 33 50 27 / 50 40 10 10 10 Stinson Muni Airport 52 59 35 51 28 / 50 40 10 10 10 && .EWX WATCHES/WARNINGS/ADVISORIES... Freeze Warning from 8 PM Monday to 9 AM CST Tuesday for Bandera- Bexar-Blanco-Burnet-Comal-Edwards-Gillespie-Hays-Kendall-Kerr- Kinney-Llano-Medina-Real-Travis-Uvalde-Val Verde-Williamson. && $$ Aviation...Oaks Short-Term/Long-Term...17
Area Forecast Discussion
National Weather Service Lincoln IL
843 PM CST Sun Nov 11 2018 .UPDATE... Issued at 835 PM CST Sun Nov 11 2018 A weak cold front, analyzed across far west central Illinois this evening is expected to push through our area tonight. Not much in the way of weather associated with the boundary at the present time. Short term models continue to indicate some patchy light precipitation may develop along and immediately behind the front later tonight/early Monday morning but amounts look to be quite light, if it occurs at all. HRRR soundings slow to saturate the lower levels overnight so the current low POPs over the central sections of our forecast area look good for late tonight. As the boundary continues to slide into southeast Illinois on Monday, an upper level trof will rotate east across the Great Lakes. In addition, parts of our area will be in the favorable right rear quadrant of a speed max at 300 mb with more significant lift noted on deterministic models with the speed max, especially just to our south, so POPs increase to likely or higher across south central through southeast IL during the day. Snowfall amounts look to be on the light side, generally an inch or less, roughly along and south of a Jacksonville to Champaign line. Current forecast looks reasonable at this time with only a few minor tweaks to the grids based on early evening trends. As a result, no ZFP update is needed at this time. && .SHORT TERM...(This evening through Monday night) ISSUED AT 330 PM CST Sun Nov 11 2018 1029 mb high pressure near the mid Atlantic coast was ridging westward into the mid MS river valley at mid afternoon. This was keeping a dry and cool air mass over central and southeast IL today with 3 pm temps 40-45F. A weak 1019 mb surface low pressure was just nw of Lake Superior with its cold front extending through western WI into eastern IA and nw MO. Mid level clouds were south of I-72 while some passing cirrus clouds along and north of I-72. Radar mosaic shows some light radar returns along and south of I-70 into central MO but this appears to be virga coming out of mid level clouds with base of 9-10k ft. Plus air mass quite dry with temp/dewpoint spreads of 20-27F. Models continue to keep CWA dry through this evening as mid level clouds increase over central IL. Some 850-925 mb frontogenetic forcing to develop a band of light snow into central IL during overnight into Mon morning, mainly between the IL river and north of I-70 as surface cold front moves se across CWA. Little or no snow accumulation expected with this initial band of light snow. Lows overnight mostly in the upper 20s, but range from mid 20s nw of the IL river to around 30F in southeast IL. Highs Mon range from lower 30s along and nw of I-55, to the upper 30s to near 40F in southeast IL. 1012 mb surface low pressure off the south Texas gulf coast to track ne to the LA delta by 6 pm Mon, and move or reform off the mid Atlantic coast by sunrise Tue, then deepen up the New England coast on Tue. Better chance of light snow to occur Mon afternoon and Mon evening se of the IL river from this southeast US storm system. A mixture of light rain with light snow south of I-72 by Mon afternoon and mainly light rain se of I-70 Mon afternoon. But colder air arriving late Mon into Mon evening to change mix pcpn to all light snow. Though southeast IL could see a chance of light freezing rain/drizzle too during Monday night. Snow accumulations up to 1 inch possible along and south of I-72 and from I-70 north Mon afternoon and Mon evening with light ice around 0.05 inch or less in southeast IL Mon night. Colder Mon night with lows ranging from mid teen nw of the IL river to mid 20s near Lawrenceville. Wind chills will drop into the single digits during overnight over central IL. .LONG TERM...(Tuesday through Sunday) ISSUED AT 330 PM CST Sun Nov 11 2018 Dry and unseasonably cold wx expected Tue through Wed across CWA as Canadian high pressure settles into the MS river valley on Tue night into Wed morning. Despite return of mostly sunny skies Tue, it will be quite cold with brisk nw winds. Highs only in the upper 20s in central IL and lower 30s in southeast IL on Tue. Tue night looks to be the coldest night across the CWA with lows in the teens. Record lows for Tue/Nov 13 and Wed/Nov 14 along with record cold highs for Tue/Nov 13 are listed in the climate section below. A fair amount of sunshine Wed with light winds but still pretty cold with highs in the mid to upper 30s. Lows Wed night in the low to mid 20s, similar to readings we had this past night. The 12Z models are now showing a strong cutoff 500 mb low moving into ne AR by sunrise Thu, and lifting ne over the Ohio river valley on Thu night. GFS model appears too fast with spreading qpf into se IL overnight Wed night and prefer the slower Ecmwf model. The GEM model is even slower, but followed middle of the road with Ecmwf model. Best chances of light pcpn will be east of IL river on Thu, with mainly light snow south of I-72 Thu morning and chance of rain showers east of IL river Thu afternoon. Pcpn turns to light snow during Thu evening and diminishes overnight Thu night. Could be some light snow accumulations around 1 inch Thu night in eastern IL. Highs Thu in the upper 30s and lower 40s. Lows in the upper 20s Thu night. Highs Fri of 40-45F. A broad upper level trof lingering over Great Lakes and into the Ohio river valley to keep us on the cooler side next weekend with highs in the mid 30s to lower 40s. Chances of light pcpn look low with a few weak short waves passing through the trof. Extended forecast models show a milder trend during Thanksgiving week as upper level heights rise over the Midwest and upper level flow becomes more zonal. Climate Prediction Center`s 8-14 Day Outlook for Nov 19-25th has 40-50% chance of above normal temperatures over IL with equal chances of above and below normal precipitation. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 552 PM CST Sun Nov 11 2018 VFR conditions are expected through 12z with a slow lowering of the cigs expected on Monday with precipitation approaching from the southwest. Looking for mainly mid level clouds tonight which will gradually lower to low VFR with MVFR cigs expected by late morning or early afternoon, excpt in PIA where we will hold with low VFR cigs. We may see some light snow develop over our west and southwest Monday morning with a better threat for light snow at SPI, CMI and DEC late morning through the afternoon hours. Light mostly northerly flow expected tonight will increase out of a north to northwest direction on Monday with speeds of 10 to 15 kts && .CLIMATE... Issued at 300 PM CST Sun Nov 11 2018 Record Temperatures for Tuesday and Wednesday: 11/13 11/13 11/14 Coldest Coldest Coldest Location Low (year) High (year) Low (year) Champaign.... 7 (1986) 22 (1986) 10 (1986) Charleston... 7 (1986) 24 (1986) 10 (1986) Danville..... 9 (1986) 22 (1986) 10 (1976) Decatur...... 7 (1986) 22 (1986) 8 (1986) Effingham.... 9 (1986) 27 (1940) 9 (1986) Galesburg.... 4 (1986) 18 (1986) 8 (1940) Jacksonville. 7 (1986) 25 (1940) 7 (1986) Lawrenceville 17 (2013) 29 (2014) 18 (2014) Lincoln...... 5 (1986) 27 (1995) 7 (1986) Normal....... 5 (1986) 21 (1940) 7 (1940) Olney........ 10 (1920) 29 (1911) 12 (1940) Paris........ 9 (1986) 24 (1986) 10 (1986) Peoria....... 5 (1986) 22 (1986) 8 (1940) Springfield.. 7 (1986) 23 (1986) 12 (1940) Tuscola...... 8 (1986) 26 (1986) 10 (1986) && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Smith SHORT TERM...07 LONG TERM...07 AVIATION...Smith CLIMATE...37
Area Forecast Discussion
National Weather Service San Francisco Bay Area
355 PM PST Sun Nov 11 2018 .SYNOPSIS...Smoke will continue to impact the area through Monday with dry conditions and light offshore winds continuing. Seasonably mild with continued dry weather through much of the upcoming week through next weekend. A possible pattern shift by Thanksgiving. && .DISCUSSION...as of 1:45 PM PST Sunday...Smoke impacts from the Camp Fire continue to be the main weather item of note across the Bay Area. Red Flag Warning remains in place through 4 pm today. Strongest offshore winds will ease as daytime heating is lost. However very dry conditions continue across the region with low humidity values. Currently the main smoke plume from the Camp Fire is pointed towards northern Sonoma County. Forecast wind flow will then bring much of the smoke southward across the Bay Area. Latest 18z hrrr smoke model keeps vertically integrated smoke values elevated through Monday for much of the Bay Area. Keep in mind any changes in fire activity will obviously change the potential smoke impacts but for now expect air quality impacts at least through Monday for much of the Bay Area. Smoke is also impacting high temps with most sites staying in the upper 60s to lower 70s. The smoke is enough to shave at least a few degrees off the model guidance. In the short term we are seeing some of the northeast winds mix down into the valleys this afternoon with northeast wind gusts to 28 mph at Oakland Airport. Large scale gradients are easing with only 10 mb offshore now thus lighter winds tonight in the hills. Large scale pattern keeps a solid ridge over CA at least through Weds. This will keep warm and dry weather in place but widespread smoke could inhibit some of the warming potential. Nonetheless still expect daytime highs upper 60s to mid 70s. The ridge may weaken by Thursday but the pattern remains tranquil. Expect dry and seasonable weather Thursday through the upcoming weekend. Models have been consistent in changing to a more active or at least zonal type flow starting next week. The ecmwf has a weak shot of some light rain by around Nov 19th with better chances around Nov 21-22nd. However confidence remains low to medium overall on details in terms of rainfall but higher confidence in temps at least dropping back to near or slightly below normal around Thanksgiving. && .AVIATION...As of 3:55 PM PST Sunday...For 00z TAFs. Smoke continues to impact area terminals this afternoon with scattered to broken cigs and reduced vsbys across the region. Slantwise vsbys have been a major issue and will continue to cause problem during approach and result in delays in air traffic for the next 24 to 36 hours. Light offshore winds will continue through much of the period. Vicinity of KSFO... Moderate NE winds will persist through this afternoon and then will ease after sunset. Will keep 6sm HZ FU and Few-Sct030-035 in the TAF through the period as a result of the smoke. SFO Bridge Approach...Similar to KSFO. Major smoke impacts due to slantwise problems. Not seeing much improvement as upstream smoke remains thick. Monterey Bay Terminals...Light winds will turn easterly this evening and persist through the overnight hours. Smoke will continue to bring reduced vsby and possible cigs. && .FIRE WEATHER...As of 1:45 PM PST Sunday...Red Flag Warning remains in effect through 4 pm Sunday. Lighter offshore winds will continue tonight into Monday. Humidity recovery will continue to be very poor in the hills, generally under 30 percent. Warm and dry weather with continued light offshore flow at least through midweek will keep fire weather conditions near critical but no strong wind events are forecast. Fuel conditions remain at record dry levels. No rain forecast at least through next Sunday. && .MARINE...as of 03:39 PM PST Sunday...Northerly to easterly winds will persist over the coastal waters as high pressure remains locked in place through tonight. Light southerly winds will develop on Monday before transitioning back out of the northwest by midweek. Small swells will continue before a northwest swell builds by midweek. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...None. && $$ PUBLIC FORECAST: RWW AVIATION: CW MARINE: MM FIRE WEATHER: RWW 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
Area Forecast Discussion
National Weather Service Reno NV
545 PM PST Sun Nov 11 2018 .UPDATE... The lake wind advisory for Lake Tahoe has expired. Winds are diminishing across the lake, but choppy waves will continue through this evening. Otherwise, the forecast remains on track, with a cold night expected. CL && .PREVIOUS DISCUSSION... /Issued 109 PM PST Sun Nov 11 2018/ SYNOPSIS... High pressure will lead to dry and stagnant conditions through at least Thursday. Localized air quality issues are possible under valley inversions. Some smoke from California may filter into the Sierra starting Tuesday if fires remain active. A pattern change next week may open the door to a couple weak storms but no major precipitation events are anticipated. DISCUSSION... * Today`s weather has been characterized by a super dry airmass and strong east winds at ridgetop levels. Some of this wind is making it down to Lake Tahoe with gusts above 30 mph. Latest HRRR has winds relaxing after 6 PM so will extend lake wind advisory until then. * Strong and persistent ridging will overspread the region Monday through much of this week. This leads to classic air stagnation conditions in valleys with morning inversions, low mixing heights, and weak transport winds. Air quality issues from local sources remain possible. Transport winds generally E/NE but simulations show some W winds starting Tuesday over the Sierra which could bring some CA fire smoke into those regions. * Simulations all show a pattern shift next week with a series of troughs taking bites out of the persistent ridge. So we could see a couple storms, likely in a weak or decaying phase, next week. No atmospheric rivers showing up so any storms would probably produce just light precip, gusty winds. Peak holiday travel next week, however, does up the impact potential from even just weak storms. -Chris AVIATION... Expect VFR conditions at regional terminal areas today. Northeasterly winds will continue with occasional surface gusts 15-20 kts possible this afternoon. Winds continue to blow atop the Sierra crest, with current observations indicating gusts 45-55 kts. Turbulence is possible over and west of the Sierra this afternoon and early this evening. Surface winds will decrease after sunset, with wind gusts to 30 kts still possible along and west of the Sierra crest overnight into Monday. Smoke from California fires will remain west of the Sierra crest today and tonight due to northeasterly flow. For Monday and Tuesday, high pressure will move onshore across the western US, which will cause winds to diminish at the surface and aloft. Westerly flow aloft may allow smoke to be transported across the Sierra, which could make for hazy skies, especially if fires remain active in California. -Johnston && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
Area Forecast Discussion
National Weather Service Sacramento CA
318 PM PST Sun Nov 11 2018 .SYNOPSIS... Dry weather continues with cool nights and near to above normal days through the week. Critical fire weather conditions continue through Monday morning, with breezy winds and low humidity. Widespread smoke from the Camp Fire will continue to impact much of the area. && .DISCUSSION... Latest satellite imagery shows interior NorCal on the east side of a persistent upper ridge over the eastern Pacific. Widespread smoke and haze continues to envelop the region due to the Camp Fire. Current observations indicate Valley gusts up to 25 mph, and local wind gusts of 30 to 40 mph over the mountains. Gradient is trending down, with lighter wind expected by Monday afternoon. Winds will gradually diminish across the Valley tonight as pressure gradient relaxes. Gusty wind will persist over the eastern foothills/mountains through Monday morning, then lighter wind is anticipated in the afternoon. The combination of wind, low humidity, and near record dry fuels is bringing critical fire weather conditions. Therefore, a Red Flag Warning is in effect for the Central Sacramento Valley southward until 9 PM, and until Monday morning for higher elevations. Wildfire smoke continues to be an issue, with poor visibility for some spots, and bad air quality. Latest HRRR smoke forecast indicates smoke continuing to impact the region mainly from Chico southward, with some improvement on the west side of the Valley. Periods of dense smoke will be possible across the Valley for the next few days, although it`ll be difficult to determine breaks in smoke. Make sure to check on sensitive groups, and go to airnow.gov for air quality information. The region will remain under the influence of a persistent upper ridge, resulting in dry weather. Smoke might help to keep temperatures cooler the next couple of days. High temperatures will be in the 60s to mid 70s for the Central Valley, with mostly 50s to 60s for the foothills and mountains. Cold overnight temperatures are expected mainly over the Central Sacramento Valley southward, with lows in the 30s. Lows will be in the 10s to low 20s across mountain basin locations. && .EXTENDED DISCUSSION (Thursday THROUGH Sunday) Broad upper ridge forecast to continue across the region later in the week maintaining dry weather with mild days and cool nights, and no strong wind events are expected. Forecast guidance is indicating the possibility of a pattern change as an upper trough approaches the area late next weekend into early next week. However, confidence in details remains low so have kept the area dry for now. && .AVIATION... Widespread MVFR with local IFR expected to continue next 24 hours south of KCIC as smoke continues to spread southward from the Butte County wildfire. VFR to the north of KCIC and over the higher elevations of the Sierra Nevada. Local northerly wind gusts to 25 kts over far west side of the valley will decrease after 02Z. Local northeast wind gusts to 30 kts will continue over the west slopes northern Sierra Nevada. && .STO WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 7 AM PST Monday for Northern Motherlode From 1000 to 3000 Ft. Includes portions of Nevada-Yuba-Placer- Amador and ElDorado Units-Northern Sierra Foothills from 1000 to 3000 Ft. Includes portions of Shasta-Trinity and Butte Units- Northern Sierra Including Lassen NP and Plumas and Lassen NF/S West of the Sierra Crest (West of Evans Peak-Grizzly Peak- Beckworth Peak)-Northern Sierra Including the Tahoe and ElDorado NF/S West of the Sierra Crest-Southern Motherlode From 1000 to 3000 Ft. Includes portions of Calaveras-Tuolumne Unit-Stanislaus NF West of the Sierra Crest. Red Flag Warning until 7 AM PST Monday for Burney Basin and Northeast Plateau in Shasta County Including Northwest Lassen NF north of Lassen NP-Eastern Mendocino NF-Eastern Portion of Shasta/Trinity NF-Lake County Portion of Lake-Napa-Sonoma Unit- Northern Sacramento Valley to Southern Tehama County Line Below 1000 Ft-Southeast Edge Shasta-Trinity NF and Western Portions of Tehama-Glenn Unit. Red Flag Warning until 9 PM PST this evening for Carquinez Strait and Delta-Central Sacramento Valley in Glenn, Colusa, Yuba, Northern Sutter, and Butte County Below 1000 Ft-Southern Sacramento Valley in Yolo-Sacramento Far Western Placer, southern Sutter and Solano County Below 1000 Ft. && $$
Area Forecast Discussion
National Weather Service Topeka KS
816 PM CST Sun Nov 11 2018 .UPDATE... Issued at 816 PM CST Sun Nov 11 2018 Precip has been slow to develop due to low level dry air and temperatures have remained warmer than expected early this evening. Since snow was expected to have already begun across much of the area by now, think snow totals could end up being a little lower than previously forecast. Adjusting the forecast just for the temps and delaying the change over to snow has lowered totals along interstate 70 across the northern portions of the advisory. Will keep the advisory going as is, but back off slightly on snow amounts. It still looks as if east central KS, or areas southeast of a line from Council Grove to Topeka, could end up with 1 to 3 inches. The main shortwave is just know beginning to move out into the high plains of NM so there remains some decent dynamics to lift across the area overnight and Monday morning. This is where the 00Z NAM is now showing a second band of precip through the morning. && .SHORT TERM...(This evening through Monday) Issued at 348 PM CST Sun Nov 11 2018 A potent band of snow sets up along and south of Interstate 70 this evening into Monday, producing a swath of 1-3 inches of snow with locally higher amounts towards the I-35 corridor. The synoptic setup early this afternoon features a sharp, positively-tilted upper-tropospheric trough diving into the Four Corners region, with resulting H500 height falls and increasing 290-300K isentropic upglide fueling a wide swath of precipitation over western Kansas. Increasing 750-650mb frontogenetical forcing was leading to banding features both within the snow shield in western Kansas and now further east over the last few hours along a northwest-to-southeast-oriented swath between Wichita and Emporia. Despite warming up into the low to mid 40s, dynamic cooling within this band is dropping surface temperatures into the upper 30s and wet bulb values to near freezing, allowing for at least a mixture of rain and snow to be observed. The development of this band was modeled modestly well by the 12Z CAM suite, with the NAM core models (NMM/NAMNest) doing the best in defining the banded nature of the precip shield and the resulting cooling occurring under it. The best juxtaposition of isentropic upglide, coupled with mid- level frontogenetical forcing under a region of negative EPV within the DGZ, is still on track to occur late this evening along and south of I-70. Most CAMs generating two to three tenths of an inch of 6 hourly QPF with this band, with minor variability noted in its placement between the various solutions. This could easily produce a short-period of 1"+/hr snowfall rates in the strongest bands. The transient nature of this lift means that any deviations in its timing or location will have a significant impact on snowfall amounts. There will likely be a sharp cutoff in snowfall amounts north of the I-70 corridor, with barely measurable snowfall totals expected near the Nebraska border. The other big question will be how quickly the near surface thermal profile cools to support snow. Given how quickly the transition to snow occurred in central Kansas earlier this afternoon, updated the hourly weather forecast to skew the rain/snow threshold to 42/38 degrees. With dewpoints still in the low 30s and wet bulb values in the mid 30s, it is expected that the initial wave of snow will melt and have minimal impacts on the roads. However, as the profile continues to cool and slightly drier air funnels in from the north, snow accumulation will commence quickly beginning near 00Z. Did make some minor adjustments to the start time/location of the winter weather advisory to account for the orientation of this snow band. The bulk of the mesoscale forcing wanes after 06Z with continued kinematic lift maintaining a broad swath of light snow over much of the area through 12Z. A deepening DGZ on the order of 1000-1500m thick should allow this modest lift to still produce up to another inch of snow before sunrise. As an embedded PV lobe ejects northeastward from the base of the H300 trough early Monday morning, the 700mb baroclinic zone pivots over southeastern Kansas, keeping a continued threat for snow going throughout the day in the southeastern forecast area. The NAM is quite aggressive in snowfall rates within this band during the day Monday--with 6-7 inches depicted in Garnett using the Cobb snowfall technique-- and this potential will need to be watched closely. Did extend the winter weather advisory until 00Z tomorrow in the southeastern forecast area to account for these impacts. Increasing CAA ahead of an approaching ridge finally ushers this system out of the area around sunset Monday evening. The other concern for Monday revolves around the potential for horizontal convective roll processes to develop and produce banded snow squalls behind this main complex over north-central and northeast Kansas. The 12Z NAM is the most aggressive in this scenario, depicting a deeply mixed boundary layer over 1-km in depth with upright surface convective instability noted under the H825 inversion. Both RAP and NAM forecast soundings contain winds of 25 to 30 kts at the top of the mixed-layer, the top of which extends into the lower DGZ and would support snow as the primary precip type. The increasing dewpoint depressions at the surface may aid in sublimating some of the snow before it reaches the ground. For this reason, have kept only the mention of flurries throughout the day across the forecast area. However, any stronger HCRs, coupled with the blustery winds, could bring brief, localized periods of travel difficulties. These snow showers wane as diurnal heating lessens in the afternoon and evening. .LONG TERM...(Monday night through Sunday) Issued at 348 PM CST Sun Nov 11 2018 Little sensible weather is forecast for the rest of the week with temperatures lingering below normal. A sharp meridional upper-tropospheric longwave trough will be positioned overhead at the start of the period, with split/northwesterly upper flow ensuing for the bulk of the work week. A 1030mb surface high pressure cell becomes the dominant feature over the central plains by Tuesday, with continued CAA ahead of the ridge pushing lows down into the teens Monday night. The ridge passes east of the forecast area by late Tuesday, with weak southerly flow setting up for Wednesday and Thursday. Recent EC/GFS/GEM runs have backed off on the strength of the downslope- induced H850 thermal ridge for midweek, with the resultant surface highs slipping five to eight degrees lower than what was forecast yesterday. The H500 ridge translates through the region on Thursday, with height falls on the backside of the ridge facilitating the passage of a weak surface trough devoid of precip on Thursday night. The upper-level pattern over the western CONUS amplifies for late in the week, with an increasing threat of transient PV lobes bringing light snow to the region; however, confidence in the timing and location of these disturbances over the weekend is low and there is a large spread in the longer range guidance. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday) Issued at 527 PM CST Sun Nov 11 2018 Most of the guidance suggests the terminals should be on the northern fringes of the main snow band tonight with some dry air in place that needs to be overcome. With this in mind, have a VFR forecast for a few hours into the evening. Think the main window for some MVFR conditions and -SN is between 03Z and 07Z. After 07Z the banded precip is expected to shift southeast. The next wave of energy is progged to move across southeast KS by 12Z. This could bring some -SN back into TOP and FOE mid morning. Then forecast sounding develop steep low level lapse rates during the day Monday suggesting some potential for snow showers. Confidence is marginal in both these things bringing SN into the terminals so have a VCSH for now. && .TOP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 PM CST Monday for KSZ040-054>056- 058-059. Winter Weather Advisory until 6 AM CST Monday for KSZ021-022-026- 034>039. && $$ UPDATE...Wolters SHORT TERM...Skow LONG TERM...Skow AVIATION...Wolters
Area Forecast Discussion
National Weather Service Tulsa OK
927 PM CST Sun Nov 11 2018 ...UPDATE... .DISCUSSION... Precipitation continues to expand from eastern NM through the TX Panhandle and extending across southern KS. A notable uptick in precipitation intensity has been observed across the TX Panhandle with recent reports of thundersnow, and this band of associated forcing will begin to extend eastward overnight with an expected increase in precip into NE OK late tonight. Additionally, the widespread ongoing convection over E TX will gradually lift northward into SE OK later tonight before spreading more east of the forecast area early Monday. Regarding the winter weather potential, the recent operational HRRR runs have verified well with the sfc freezing line, where as the recent 00z NAM showed considerable error across western KS with its 3HR fcst. This trend will be closely followed as the aforementioned NAM run is more aggressive with the freezing line south of I-44 during the the period of strongest lift around mid morning Monday. Also, data trends have been more northward with the mid level dry intrusion which, if verified, would quickly limit the snow potential southeast of Interstate 44 during the day Monday. In typical fashion, Southern Plains winter event are seldom straight forward. The updated forecast will adjust for precip coverage trends through the early morning hours otherwise the overnight forecast remains on track. && .PRELIMINARY POINT TEMPS/POPS... TUL 34 35 18 35 / 60 100 10 0 FSM 36 38 26 38 / 70 100 20 0 MLC 36 37 23 36 / 70 100 10 0 BVO 31 32 17 37 / 70 100 10 0 FYV 34 35 21 33 / 50 100 20 0 BYV 34 35 20 33 / 40 100 20 0 MKO 35 36 21 35 / 60 100 10 0 MIO 33 34 18 33 / 60 100 10 0 F10 35 36 21 36 / 60 100 10 0 HHW 39 40 27 39 / 80 100 10 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Winter Weather Advisory from 3 AM to 6 PM CST Monday for OKZ054>067. AR...Winter Weather Advisory from 3 AM to 6 PM CST Monday for ARZ001- 002-010-011. && $$ SHORT TERM...07