Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/17/21

National Weather Service Albany NY
941 PM EST Sat Jan 16 2021 .SYNOPSIS... An upper level low will continue to impact eastern New York and western New England overnight through the rest of the weekend. Lake enhanced snow will continue across the southern Adirondacks through Sunday morning, as westerly upslope snow continues across the higher terrain of the southern Greens mainly above 1500 feet. Otherwise, mostly cloudy conditions persist with some scattered snow showers and flurries and blustery conditions for the remainder of the region into Monday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Winter Storm Warning remains in effect until noon Sunday for northern Herkimer and Hamilton Counties and for the southern Green Mountains for the elevations above 1500 feet. As of 940 pm EST...A cutoff low is centered over NY and PA tonight. Cyclonic vorticity advection continues around the cutoff, as the sfc cyclone according to the RAP is 987 hPa over west-central Maine. The forecast area has seen a transition to westerly upslope orographic snowfall tonight over the northern Taconics, southern Greens and northern Berkshires. Lake enhanced snowfall continues over the Tug Hill Plateau spilling into the southern/western Adirondacks. Lake instability class remains conditional with marginal Delta T`s and instability values of a couple hundred J/kg. The activity is not as organized, but still a good fetch off the lakes. The latest Froude Numbers from the NAM/GFS indicates values rising into the 1-2 range where the flow is critical with the strong west to southwest winds where the pcpn falls close to the mtn ridge crest and on the lee side. Accumulations should increase again along the southern Greens and western Adirondacks where we are expecting an additional 3-6" at night. The Warnings will remain in place. Some retooling of the PoPs was done based on the radar returns and the latest 3-km HRRR. Until noon tomorrow...Additional snow accumulations of 4 to 8 inches are expected across northern Herkimer and western Hamilton counties. However across southern Vermont additional snow accumulations of 1 to 4 inches are expected below 1500 feet in elevation with 4 to 12 inches above 1500 feet. South and east of the Capital Region will have less activity tonight with some partial clearing near the mid Hudson Valley. Some light snow showers are possible in the Mohawk Valley and the Upper Hudson valley. Lows tonight will be in the mid 20s to lower 30s. West to southwest winds will pick up across the area with gusts of 25 to 35 mph. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Winter Storm Warning remains in effect until noon Sunday for northern Herkimer and Hamilton Counties and for the southern Green Mountains for the elevations above 1500 feet The upper low will continue to move gradually northward as ridging induced ahead of the next approaching short wave builds in during the afternoon into the evening hours Sunday. This ridging will quickly weaken and shift off to the east as the long wave trough deepens to our west. The trough axis will move across the area region Monday along with its associated cold front. The lake enhanced snow and upslope snow will continue into Sunday morning with overall precipitation chances decreasing but not ending as the day progresses and the favorable flow gets disturbed. As the upper trough axis and its associated cold front approach and cross the region we will have continued chances for snow showers mainly across the higher terrain through the day Monday. Dry out Monday night with some clearing expected. Above normal temperatures with a more seasonable airmass being ushered Monday night in the wake of the cold front. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Focus during the long-term period continues to surround a couple of rather weak shortwaves/associated low pressure systems that will bring a couple of chances for some light snow to the forecast area. Deterministic forecast models and their ensembles continue to advertise a shortwave approaching the forecast area during the day on Tuesday. Clouds will be on the increase during the day on Tuesday with precipitation in the form of snow moving into the region from west to east Tuesday evening/night. Right now, it appears that most of the snowfall will be confined to the SW Adirondacks, western Mohawk Valley, the Berkshires, and southern VT. Snow showers will linger into Wednesday morning before coming to an end by Wednesday afternoon. Snow accumulations are expected to be light with this storm system/shortwave being weak and coming with limited moisture. We`ll get a brief break Wednesday afternoon/evening into Thursday morning before our next chance for some snow showers as a strong, larger storm system approaches from the northwest. Wednesday evening into Thursday, clouds will increase eventually becoming mostly cloudy by Thursday morning. Light snow will overspread the area from west to east Thursday morning to Thursday afternoon. Synoptic snow will persist into Friday before transitioning over to lake enhanced snow. Upslope snow will also be occurring during this event. Lake effect snow showers/upsloping are progged to persist till Friday evening before coming to an end. There could still some lingering lake effect snow showers over Herkimer county into Saturday morning. Once again, snow amounts are expected to be light across most areas with highest amounts confined to the higher elevations. A lot of this is due to the fact that 1)the center of the storm system will past well to our north meaning that the greatest forcing will be north of our area in closer proximity to the center of the storm system, 2) the fact that the storm system is expected to weaken as it tracks across Ontario and Quebec, and 3) similar to storm systems associated with the northern jet, there being limited available moisture. During this long-term period, the northern U.S. including the Northeast U.S. will be under a mean flat upper trough. This will translate to a cooler than normal bias in temperatures at the surface during this time period. Daytime high temperatures will be in the 20s/30s (with some teens across the SW Adirondacks). Overnight low temperatures will be in the teens and 20s to start the period, but will trend downwards into the teens and single digits by Saturday night/Sunday morning. Low temperatures could fall below zero across the SW Adirondacks Saturday night into Sunday morning. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... A cutoff low continues to be situated over NY and PA tonight. A series of disturbances rotating around the low tapping lake moisture will continue cloudy conditions with scattered snow showers and flurries from KALB north to KPSF tonight through Sunday. Some low stratus locally dense fog/mist continues to impact KGFL early this evening with LIFR/IFR conditions. This should break up between 00Z-04Z/SUN with MVFR/VFR conditions returning as a disturbance moves through. MVFR cigs will persist thereafter for most of the night with snow showers/flurries in the vicinity. KALB will also be in the MVFR/low VFR range in terms of cigs. A batch of snow showers will move through between 00Z-02Z and a TEMPO group was used for them. VCSH groups were used most of the night with CIGS in between 2.5-3.5 kft AGL. KPSF will have some upslope snow showers with CIGS/VSBYS lowering from MVFR levels to occasional IFR or even LIFR levels. A TEMPO group was used to address this prior to 04Z with MVFR cigs in the 2-3 kft AGL with VCSH groups overnight. KPOU will continue to have VFR conditions mid level clouds overnight. After 12Z/SUN...Expect CIGS to continue in the MVFR/low VFR range for KGFL/KALB/KPSF through the morning and into the afternoon. In the cyclonic flow, there will continue to be some lake effect, upslope flow snow showers and flurries. PROB30 groups were used at KALB from 13Z-18Z/SUN with MVFR conditions, and 17Z-21Z at KPSF. KGFL we kept with VCSH groups. KPOU will see some stratocumulus develop in the sct-bkn range range around 3.5 kft AGL in the late morning into the afternoon. The winds will be southwest to west at 8-15 kts tonight with some gusts to 18-25 kts. The winds will increase from the west at 12-20 kts in the late morning into the afternoon with some gusts around 30 kts at KALB/KPSF. Outlook... Sunday Night: Low Operational Impact. NO SIG WX. Martin Luther King Jr Day: Low Operational Impact. Chance of SHSN...SN. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: Low Operational Impact. Slight Chance of SN. Wednesday: Low Operational Impact. Breezy. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Moderate Operational Impact. Chance of SN. && .HYDROLOGY... No widespread hydrological issues are not expected in the Albany Hydro Service Area through the end of next week... Total liquid equivalent from the storm system last night into today ranged from a half an inch to an inch and three quarters. The majority of higher liquid equivalent occurred over the higher terrain of the eastern Catskills, southern Adirondacks, Berkshires and southern Greens. Additional lake enhanced and upslope snowfall will occur tonight into Monday with the highest amounts over the western Adirondacks, and the southern Green Mountains. A clipper type low pressure system may bring some light snow Tuesday night into Wednesday. Overall flows will lower with the colder temperatures and the main ptype will be snow. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Winter Storm Warning until noon EST Sunday for NYZ032-033. MA...None. VT...Winter Storm Warning until noon EST Sunday for VTZ013-014. && $$ SYNOPSIS...IAA/Wasula NEAR TERM...IAA/Wasula SHORT TERM...IAA LONG TERM...Evbuoma AVIATION...Wasula HYDROLOGY...Wasula
Area Forecast Discussion
National Weather Service La Crosse WI
534 PM CST Sat Jan 16 2021 .SHORT TERM...(This evening through Sunday) Issued at 149 PM CST Sat Jan 16 2021 This afternoon the Upper Mississippi Valley region was situated in between systems, beneath a low-amplitude mid-level ridge. Our recent occluded low was advancing towards New England while a developing shortwave was digging into the Northern Plains. Locally, we`ve had some nuisance snow showers/flurries/drizzle to contend with today due to a pesky 950-925mb frontogenesis band just west of the Mississippi River. The RAP shows this fgen band fizzling out over the next few hours as it creeps up to the MS River, so that should lead to an overall diminishing trend. Will still keep mention of flurries going given the very moist low levels and some weak low level omega. That upstream shortwave will be the feature of interest for tonight as it drops into our region. While forcing will be weak in tandem with limited moisture, there is model consensus for it to squeeze out some light snow as it drops southeast through the region tonight into early Sunday. QPF is very light, so the snow is not expected to amount to more than a coating to perhaps a half inch in spots. RAP/HRRR comp reflectivity point to south of I-94 as the main area of impact through early Sunday afternoon, but have at least flurries mentioned elsewhere for most of the day. Lows tonight will range from around 20 to the mid 20s across the area. Sunday`s highs will range from mid 20s to around 30. .LONG TERM...(Sunday night through Saturday) Issued at 149 PM CST Sat Jan 16 2021 There is no real clear or strong signal for precipitation over the next several days, just some spotty low chances here and there. The region will generally be under a northwest to southeast oriented upper-level flow pattern. Multiple shortwaves pass through this flow bringing several low chances for precipitation, but not expecting much for accumulations if any at this time. Some light snow or flurries may persist into the overnight hours on Sunday. On Monday, another shortwave system passes through the region, but the best chances for precipitation remain south of the area where there is better forcing and moisture available. From mid-week onward, model guidance is pinning a surface low pressure system to track eastward through southern Canada while remaining north of the Great Lakes Region. Associated troughs extending from this low pass through the local area. Cold air advecting into the area in wake of the passing waves will cool afternoon temperatures into the teens for Friday and Saturday. Otherwise, expect afternoon temperatures to be in the 20s to low 30s, with low temperatures from the single digits to low 20s. Decided to stick with the blended model guidance keeping precipitation chances nearly dry into the weekend. There is still plenty of spread between the models with handling how these weak shortwaves evolve and track through the region. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 534 PM CST Sat Jan 16 2021 Several weak troughs in northwest flow aloft will keep cloud cover and intermittent light snow or flurries going through the next 24 hours. Plan on IFR/LIFR conditions at KRST through the period while mainly MVFR conditions expected at KLSE. Surface winds will be light northwesterly, generally below 10kt. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Kurz LONG TERM...Peters AVIATION...DAS
Area Forecast Discussion
National Weather Service Dodge City KS
543 PM CST Sat Jan 16 2021 ...Updated for aviation discussion... .SHORT TERM...(This evening through Sunday) Issued at 311 PM CST Sat Jan 16 2021 A cloudy and relatively warm afternoon as temperature trends from the HRRR model warm temperatures about 10 degrees above normal mid January highs. Many location might see an increase to sustained wind speeds around 20 to 25 mph with the frontal passage. As the cold front drops in Today, the drier air over central Kansas will be taken over by higher dew points behind the boundary in the 20s and 30s. The secondary upper branch of the synoptic trough moves in Tonight, providing deep layer subsidence and clearing sky. There will be just enough surface pressure gradient to prevent winds from going completely light, at around 10 knots overnight. There is not a large spread amongst the models for overnight lows, with plenty of consensus for the mid 20s overall. .LONG TERM...(Sunday night through Saturday) Issued at 311 PM CST Sat Jan 16 2021 We will remain under northwest flow on Sunday, however receive much more insolation though the day. A reinforcement of cooler air should cap temperatures at about 5 degrees cooler as well. A slight bump in temperatures is likely Monday as weak downslope will be present ahead of a dry surface trough. All of this is just in advance of a noticeable cold front on Monday night. We should see he coolest temperatures of the week Tuesday. That will also bring more breezy/windy conditions late Tuesday/Wednesday as well as a bump in temperatures to well above normal for highs Wednesday. The Global spectral models are interesting toward the end of the 7 day period with potential for a significant cold front around Thursday night or Friday. With the colder air in place and an advancing synoptic scale trough moving though the four corners region over the weekend, the possibility for a winter storm impacting our region for the later half of the weekend looks reasonable. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 536 PM CST Sat Jan 16 2021 North winds will diminish through 01z and then increase to 12-14kts with daytime heating between 16 and 22z. Winds will become light toward the end of the period with the loss of daytime heating and surface high pressure briefly building across the high plains. VFR conditions can be expected with only scattered cloud AOA070. && .PRELIMINARY POINT TEMPS/POPS... DDC 27 49 28 52 / 0 0 0 0 GCK 25 48 26 50 / 0 0 0 10 EHA 27 49 28 51 / 10 0 0 10 LBL 25 50 25 51 / 0 0 0 0 HYS 26 49 26 51 / 10 0 0 0 P28 28 52 27 55 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Finch
National Weather Service Hastings NE
630 PM CST Sat Jan 16 2021 ...Short Term and Aviation Update... .UPDATE... Issued at 628 PM CST Sat Jan 16 2021 Quick update on chances for passing flurries/light snow showers overnight: - Did some minor updates to both timing/area, but bottom line is any snow that does occur is still NOT expected to be a "big deal" at all. As for timing: previous forecast held off any mention of flurries/light snow showers until after midnight, but based on various short term models and upstream radar trends it appears that some of this possible activity could reach our west-northwest zones as early as 9-10 PM so have moved up timing a bit. As for coverage of overnight flurries/light snow showers, previous forecast had entire CWA (coverage area) blanketed with at least a flurry chance. However, latest short term models clearly target roughly the western 1/3 of our CWA for having the "highest" chances of seeing any limited activity, and our far east-northeast as least favored. In fact, have "rolled the dice" a little and removed any mention of flurries tonight from our far northeast zones. && .DISCUSSION...(This evening through Saturday) Issued at 227 PM CST Sat Jan 16 2021 The weather is much calmer today in the wake of the system which brought two consecutive windy days to our region (Thursday/Friday) and this system has departed well to our east and was centered in eastern OH around midday. The pattern aloft across our region featured northwest flow ahead of upper ridging building along the western CONUS. Tonight, a 145kt jet will nose south from the northern Rockies across the western/central plains states and will be driving a shortwave trough across our region, then deepening the trough just to our east by Sunday morning. Lift associated with the progressing wave and favorable jet dynamics may be sufficient to generate a few snow showers or flurries tonight. Short term models differ on location of this light precip with the HRRR favoring our central/eastern CWA whereas other models suggest precip more along our western zones. Given this is a light event with little if any accumulation, will maintain flurries across our entire cwa. On Sunday the forecast dries out and heights begin to rise behind the departing upper trough and we remain in between shortwaves during the daytime hours. Northwest winds will increase again as mixing deepens with gusts around 30 mph expected. Sunday night into Monday in a progressive pattern, a shortwave trough translates southeast from the northern Rockies and crosses the plains, sending a cold front south through our region. Models generate some light precip with this next system but this primarily focused across northern and eastern Neb and have maintained our dry forecast which is supported by model ensembles. Heading into next week, the weather pattern becomes split with a closed low in the southwest CONUS with our area influenced by a progressive northern stream. Warmer air advects eastward around the middle of the week and Wednesday is still shaping up to be the warmest day with high temps in the 50s ahead of an advancing trough and cold front. The forecast remains dry until Friday night/Saturday but models have trended a little slower with the next system and could see these chances getting pushed back until later next weekend. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday) Issued at 628 PM CST Sat Jan 16 2021 High confidence in VFR ceiling/visibility through at least the vast majority of the period (and TAFS reflect this), although there are few low-confidence caveats that could "mess up" this expectation at least briefly: 1) A periodic low-end VFR ceiling around 5K ft is expected mainly during the 06-15Z time frame, which if this comes in a bit lower than expected could flirt with upper-MVFR thresholds...2) There is an outside chance of a passing snow shower mainly 03-08Z that could briefly reduce visibility below VFR (currently covered with a generic VCSH/vicinity). Turning to winds: modestly-breezy surface winds and modest low level wind shear (LLWS) are the main stories. Starting with surface winds, the overall-lightest speeds around 10KT or less will occur this evening and then again very late in the period Sunday afternoon. In between however, a disturbance diving in from the north-northwest will kick up northwest winds a bit starting late tonight, but with the overall-strongest speeds focused 14-22Z...typically sustained 15-20KT/gusting 20-25KT. As for LLWS, have blanketed the entire 02-14Z time frame with a somewhat- marginal mention as winds within roughly the lowest 1,500 ft. off the surface will average around 40KT, setting up roughly 30KT of shear magnitude between the surface and this level. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...Pfannkuch DISCUSSION...Fay AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service Gray ME
1036 PM EST Sat Jan 16 2021 .SYNOPSIS... Gusty winds and heavy precipitation ends for most areas this evening with snow showers continuing in the mountains. Low pressure will gradually exit through the Canadian Maritimes on Sunday. A weak system crosses the region on Monday with another system passing south of New England late Tuesday night and Wednesday. A ridge of high pressure will cross the region Thursday, followed by another system Friday into Saturday. && .NEAR TERM /TONIGHT/... 1030PM UPDATE... Adjusted hourly precipitation chances based on latest thinking from radar trends. Still seeing areas of showers in the northern portion of the area, with a broader area of light snow moving in from the west as well. Still expect the remainder of the activity to primarily affect mountain locations where a few more inches are possible. Temperatures are still rather mild on the coastal plain and the combination of snow melt and rainfall has led to some fog mainly north of Lewiston/Augusta. Have included this in the forecast as well. 630PM UPDATE... Made some adjustments to the forecast mainly to drop the High Wind Warning and the winter headlines south of the mountains. Last of the precipitation is shifting to the northeast although another round of snow is possible up north as the low pulls away tonight, so the Winter Storm Warning will continue there. ORIGINAL DISCUSSION... RAP analysis shows low pressure sitting squarely overhead of southwest Maine at this hour with rain and snow covering most of the state, extending pack into northern and central New Hampshire. Satellite shows the deep moisture plume, along with heavy rainfall threat, has now tracked east of the area with wrap-around deformation at the nose of a LLJ responsible for what falls over our area this evening. Dual-pol radar, surface observations, and spotter reports show the rain- snow line over the foothills at about 1000 ft of elevation. Strong wind gusts are now relegated to the Mid-Coast of Maine, where the LLJ still resides, so have kept the high wind warning running there... but have dropped wind headlines elsewhere. Low pressure will continue to track north-northeastward toward the upper Saint John River Valley tonight with winds gradually turning to the southwest, then west, in its wake. Meanwhile the mid-level wave will continue to produce favorable forcing to continue snow over the mountains tonight... especially during the pre-dawn hours when the upper level dry slot shifts away and dendrite growth becomes favorable again. Thus a few more inches of snowfall is expected over the northern counties, especially at higher elevations where temperatures are more favorable. The Winter Storm Warning continues there through 7 AM Sunday to account for this. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... Today`s storm system will very slowly track north away from the area tomorrow as it becomes vertically stacked. It doesn`t pull away very quickly however... as a result tomorrow will be a fairly brisk day with cooler temperatures mainly in the 30s over the area and a stiff west wind. While the mountains and north will have clouds most of the day, breaks in the clouds toward the south and coastal plain will allow temperatures to approach 40 which produces favorable mixing conditions to bring frequent gusts of 30 kts or more to the surface. Steep low-level lapse rates along with continued cyclonic flow aloft also produce a good environment for snow squalls... while moisture depth over the lowlands don`t support widespread issues there could be a few periods over the mountains and perhaps the upper Connecticut River valley where travel will be very difficult in white-out snow and wind. Low pressure pulls away into Labrador Sunday night which allows the PGF to slacken some, thus allowing winds to gradually relax overnight. Snow showers will decrease in coverage and intensity as well with lows down into the upper teens (north) to near 30 (coast). && .LONG TERM /MONDAY THROUGH SATURDAY/... Models are in relatively good agreement bringing a short wave across the region Monday afternoon into Monday evening. A weak surface wave of low pressure may form with this feature allowing for a chance of snow showers in all portions of New Hampshire and western Maine. Temperatures will still be above normal for this time of the year, with readings in the 30s across southern and central areas. The warm boundary layer temperatures may allow for a few rain showers to mix in right along the coastline. Another weak system will cross New England Tuesday night into Wednesday. This is a clipper type area of low pressure which will allow for another chance for precipitation across Maine and New Hampshire. It will be cooler with temperatures near or just below normal for this time of the year so any precipitation should remain in the form of snow showers. The fast paced short waves will continue to race across the northern portion of the CONUS. Therefore, after a weak ridge passes the region Thursday, another system will bring a chance for a period of light snowfall or scattered snow showers to the region Friday and Saturday. While 12Z guidance remains in relatively good agreement from model to model, timing issues with snow showers may be challenging throughout the week. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... Short Term...Improvements to MVFR are already being seen over parts of southern New Hampshire and the Maine coast with further, gradual improvement to VFR through tonight. The exception is at KLEB and KHIE where -shrasn and eventually shsn will persist with restrictions overnight. These sites likely stay MVFR for CIGS tomorrow with occasional VIS restrictions in SHSN. Southeast winds are now decreasing and will gradually turn to the southwest, then west by tomorrow... becoming gusty to about 30 kts during the day. Long Term...A few weak systems will be crossing the region this week, possibly bringing periods of light snow and MVFR conditions to the region. This will most likely be Monday, Tuesday night into Wednesday and again possibly Friday into Saturday. && .MARINE... Short Term...Winds will decrease for a brief time this evening as southeast storm force winds track away and to the north of the region. Seas however will remain active with waves remaining around 10 ft at the least through tonight. An offshore gale returns late tonight through tomorrow... certainly for the outer waters, likely for Penobscot Bay, and possibly for Casco Bay. Long Term...Winds and seas will likely reach SCA thresholds on Monday and Tuesday as a westerly gradient remains over the region. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Winter Storm Warning until 7 AM EST Sunday for MEZ007>009. NH...Winter Storm Warning until 7 AM EST Sunday for NHZ001-002. MARINE...Small Craft Advisory until 1 AM EST Monday for ANZ153. Gale Warning from 1 AM Sunday to 1 AM EST Monday for ANZ150>152-154. && $$ NEAR TERM UPDATE...Kimble SHORT TERM...Cannon LONG TERM...Casey
Area Forecast Discussion
National Weather Service Hanford CA
502 PM PST Sat Jan 16 2021 .UPDATE... High Wind Watch has been issued for parts of the Sierra and Foothills on Monday and Tuesday. && .PREV DISCUSSION... /issued 115 PM PST Sat Jan 16 2021/ SYNOPSIS... A change from high pressure over the region to a dry cold front and strong winds aloft by Monday will bring strong winds to part of the area. A foggy morning and a dry, warm Sunday are forecast to occur across the San Joaquin Valley as high pressure remains in place. A couple of disturbances next week could allow for strong northeasterly winds in the Sierra Nevada and Kern County Mountains. DISCUSSION... Dense fog occurred again this morning due to the influence of the ridge trapping moisture in the lowest levels of the atmosphere. This ridge is going to remain in place tonight, so fog looks likely again for us. The the HRRR and NAMNEST are forecasting fog starting to form around midnight tonight and dissipating it around 11 AM tomorrow, so a Dense Fog Advisory has been issued for that time range across the SJ Valley north of Bakersfield. The situation gets more interesting next week as a couple of systems are try to disrupt the quiet ridge pattern we have had for a while. Model guidance is starting to get more consistent with the evolution a disturbance pushing the ridge of high pressure westward tomorrow night, which would allow for another, larger trough to move over the area on Tuesday. This second system could generate a Mono Wind event if everything were to unfold as some models are portraying, but there are a lot of moving parts for this to occur. So while confidence is slowly increasing for increased winds next week, it`s probably too early to tell if the jet axis aloft will align itself properly with the Southern Sierra Nevada to support a bona fide Mono Wind event by late Monday going into Tuesday. Regardless of exactly how this pattern unfolds, it does seem likely that increased winds will be an impact next week for several areas in our forecast area. As the week progresses, global models are showing the potential for another system to enter the region that could produce the first precip we have seen in a little while. However, we need to get through Monday and Tuesday first to really get a grasp on what happens by Friday. Nonetheless, the overall pattern does seem to favor more activity than we have seen lately. AVIATION... IFR conditions with areas of LIFR/VLIFR in fog are likely to occur after 08z Sunday through 19z Sunday. VFR conditions can be expected over the remainder of the central California interior during the next 24 hours. AIR QUALITY ISSUES... On Saturday January 16 2021... Unhealthy for sensitive groups in Fresno... Kern and Tulare Counties. Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Kings... Madera... Merced and Tulare Counties. No Burning For All in Fresno and Kern Counties. Further information is available at CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information an/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory from midnight tonight to 11 AM PST Sunday for CAZ180>188. High Wind Watch from Monday afternoon through Tuesday morning for CAZ190-192-193. && $$ public...Bollenbacher aviation....Bollenbacher
Area Forecast Discussion
National Weather Service Lincoln IL
905 PM CST Sat Jan 16 2021 .SYNOPSIS... Issued at 251 PM CST Sat Jan 16 2021 Light snow will spread across central Illinois tonight and continue into Sunday, as a storm system tracks southeast across the region. Amounts of an inch or two are likely. && .UPDATE... Issued at 905 PM CST Sat Jan 16 2021 Upper level shortwave approaching west central IL will continue to produce increasing coverage and rate of snow overnight as it moves into central IL. Initially, some reports of freezing drizzle are noted in west central IL due to shallow cloud depth but this should increasingly switch to all snow overnight as deeper lift associated with the shortwave develops. Overall, updates this evening are minimal, with afternoon forecast package in good shape overall. && .SHORT TERM...(This evening through Sunday) ISSUED AT 251 PM CST Sat Jan 16 2021 Earlier round of snow exited the forecast area by midday, with just some patches of drizzle or light snow lingering over the eastern CWA. Robust shortwave was currently located in eastern South Dakota and will close off an upper low over central Illinois Sunday morning. While precipitation remains spotty this evening, an increase in snow is expected in the 9-midnight time frame west of the Illinois River, spreading southeast after midnight. 18Z HRRR suggests the snow could be cutting off as early as midday Sunday, though will go with a more slower diminishing through early afternoon as the associated surface boundary exits eastern Illinois. Accumulations not expected to be overly generous, but an inch to 2 inches appears reasonable over most of central Illinois, with up to an inch south of I-70. Main impacts on travel would likely be in the overnight and morning hours, as temperatures creep up to the freezing mark in the afternoon. .LONG TERM...(Sunday night through Saturday) ISSUED AT 251 PM CST Sat Jan 16 2021 Lingering light snow near the Indiana border is expected to move out early Sunday evening, with mainly dry conditions following into Monday. Another shortwave is expected to drop southeast across the Dakotas Monday afternoon, before tracking across the Great Lakes region. Central Illinois will be caught up in the converging area of the northern and southern jet streams. The main synoptic models all squeeze out some QPF in a band across the mid-Mississippi Valley, though the European model is more focused south of I-70. Will add some chance PoP`s for light snow Monday night across mainly the middle third of the forecast area, though soundings show it may end as a bit of freezing drizzle as ice crystals aloft are lost. With a large upper low cutting off southwest of California early this week, the upper pattern over us won`t be conducive to any significant changes until the low weakens and ejects northeast around Thursday. Both the GFS and European model keep much of its remnants to our south, though some precipitation may spread northeast Wednesday night as a weaker wave precedes it. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 526 PM CST Sat Jan 16 2021 IFR cigs are in place across most of the central IL terminals this evening, and are expected to continue through most of the forecast period, potentially decreasing overnight as another disturbance moves into the area bringing additional light snow. This snow should bring general IFR vsbys as well starting around 05Z-07Z. Potentially lower cigs/vsbys possible locally in the LIFR range. Light snow should begin to taper off from west to east near the end of the forecast period. Winds W 7-12 kts through the period. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...37 SYNOPSIS...Geelhart SHORT TERM...Geelhart LONG TERM...Geelhart AVIATION...37
...Update to aviation forecast discussion...

.DISCUSSION... Issued at 228 PM CST Sat Jan 16 2021 An amplified weather pattern persists over North America with an upper level trough over the east coast and ridging off the CA coast per the 20Z water vapor imagery. Within the northwest flow over the Great Plains, a couple pieces of energy were noted, a short wave moving across the southern high plains and a speed max diving south through MT. At the surface, weak high pressure was seen across the central plains. For tonight and Sunday, there remains the possibility for some light snow across central KS as the speed max to the north causes a shortwave to amplify over the central plains. Models vary on the amount of saturation as the energy moves across the area, but there has been a consistent signal from the RAP and GFS for enough saturation along with some modest vertical motion for some light snow. Have left POPs less than 20 percent given the uncertainty in available moisture, but I would not be surprised if there is a narrow band of light snow (mainly a dusting) across the western parts of the forecast area by tomorrow morning. Lows tonight should fall back into the 20s with dry air in place and winds becoming light. Highs Sunday look to be pretty similar to todays with no real temperature advection progged by the models and a continued mix of sun and clouds likely. So have highs forecast to range from around 40 across the northeast where there may still be a little snow to the middle 40s south and west. A series of weak systems are forecast to move across the central plains through the first half of next week. None of these systems appears to be very dynamic for the forecast area with only the moisture in place to work with. So the forecast remains dry through Wednesday. However precip chances are non-zero. The next wave to keep an eye on is Sunday night and Monday as another shortwave digs southeast. The GFS and ECMWF tend to keep the forcing with this feature mainly north of the forecast area while the NAM shears it out as it approaches northeast KS with the bulk of energy cutting off over the southwest. Since the NAM is the only solution developing QPF over a limited part of the forecast area, have kept POPs pretty low. Another piece of energy may move across the region Wednesday. But again omega fields do not look all that impressive with generally dry mid level air. The cutoff system over the southwest is progged to weaken and move across the southern plains Thursday and Thursday night with the GFS and ECMWF keeping the moisture south of the forecast area. So only have some slight chance POPs across Anderson county as this system passes. Then shortwave ridging is progged to redevelop for the weekend with the next low pressure system lifting out of the southwest just beyond the forecast period. The national blend of models has some slight chance POPs for north central KS on Saturday. Think this may be a little premature and don`t have much confidence in precip occurring on Saturday as the deterministic solutions keep the dynamics for the best vertical motion to the west until Sunday. If this trend continues, the POPs on Saturday can probably be lowered. Temps do not look to swing a whole lot from day to day as northwest flow keeps the occasional surface high moving through the region. Wednesday has the potential to be one of the warmest days of the next seven with some decent southwesterly low level flow advecting warm air north. Have highs on Wednesday in the middle 50s for most areas. In general temps look to remain mild with readings near or just above climatological norms. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 522 PM CST Sat Jan 16 2021 VFR conditions are expected through the period. There may be a brief period of mvfr cigs in the 19Z to 22Z time period at TOP and FOE, but looks to stay to the east at this time. Winds light west to become northwest around 15 kts with gusts to 24 kts after 16Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Wolters AVIATION...53