Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/18/23

Area Forecast Discussion
National Weather Service Denver/Boulder CO
851 PM MST Tue Jan 17 2023 .UPDATE... Issued at 836 PM MST Tue Jan 17 2023 Nobody likes a dry slot. HiRes guidance isn`t showing this but taking a deeper look into all components may help. Winds are remaining more easterly for parts of the urban corridor and plains mainly along the I-25 corridor which isn`t giving us true upslope. Looking at the latest NAM cross sections, there a large amount of dry air in the 400-500mb layer which isn`t helping our snowfall development either. The RAP and NAM have surface winds finally shifting northerly sometime between 07Z-09Z. Additionally, there is still the low pressure system in western Colorado that can feed northerly flow through late Wednesday morning. Thus, there is still time and potential to receive 1-1.5 inch per hour snowfall rates meaning the better timeframe for heaviest snow falls between 09-16Z. && .SHORT TERM...(This evening through Wednesday) Issued at 230 PM MST Tue Jan 17 2023 Key Points: - High confidence, impactful winter storm through Wednesday - Deteriorating roads this evening; High impact to Wed AM commute - Heaviest snow tonight through sunrise with peak snowfall rates 1-2"/hr - Snow tapers off Wed impacts most of the day - Breezy with blowing snow in plains; Poor visibility January is, on average, the driest month of the year for a good swath of northeast Colorado, so that makes this upcoming storm particularly unique in a meteorological sense. With the center of the low currently swirling near the Four Corners, expansive mid and high level clouds have overspread the state, overrunning a low- level stratus/fog deck over the northeast plains. This area of low clouds and fog will continue to march westward, with visibilities below 1 mile become increasingly widespread in the plains over the coming hours. We`re beginning to see a few returns on radar developing over the foothills and high country, and that will only ramp up over the next few hours as snow begins to accumulate across the I-70 mountain corridor. Expect the first snow showers to begin spilling over into the Palmer Divide and urban corridor by rush hour, but heavier showers should hold off until early this evening. Most of the evening rush hour should therefore be in good shape, but there`s some potential for deteriorating road conditions for the tail end of it (6-8 PM). As a whole, the latest suite of model guidance is not much different. A slight northward nudge in storm track, and continued trend toward slower progression can be noted, but neither of these are significant enough to meaningfully alter the snowfall totals or impacts. The setup overnight will be favorable for moderate to heavy snow for most areas, with deep upslope flow extending to ~650 mb, consistently steep lapse rates, and healthy ascent collocated with a modestly deep DGZ. There are still signs of a barrier jet with a core of enhanced northerly winds over the foothills. Associated cold air advection should make the temperature profile more favorable for slightly higher snow ratios, between 12:1 and 15:1 by Wednesday morning. By the time the sun`s up, most of the foothills and I-25 corridor will have picked up between 4-8" of snow, making for pretty miserable conditions for the Wednesday commute. Snow will continue much of the day Wednesday, heavy at times in the morning in the NE plains, although we`ll gradually be losing the upslope component. On/off show showers will continue most of the afternoon with mainly light accumulations, before things dry out in the evening. Breezy conditions in the plains, with gusts 30-40 mph Wednesday, will further complicate travel conditions with blowing/drifting snow and very low visibility. Storm-total snowfall amounts are expected to range between 6 and 12 inches for the majority of the urban corridor and plains. Localized amounts of 12-16" wouldn`t be surprising, especially in the far NE plains where models are consistent with the highest QPF. 5 to 10 inches will be more common for the upper elevations of the mountains. .LONG TERM...(Wednesday night through Tuesday) Issued at 230 PM MST Tue Jan 17 2023 The storm system fully exits the region tomorrow evening with lingering light snow south and east of Denver ending. Winds and areas of blowing and drifting snow on the eastern plains will also diminish. Skies then clear overnight with cold temperatures expected. We nudged low temperatures down a couple more degrees and depending on speed of clearing we may need to go further given the fresh snow cover. The next weak storm system may approach the area by late Thursday night and Friday, or just drop south so far (well southwest of the Four Corners) to just produce some clouds/flurries and drag in a reinforcing surge of cooler temperatures. We`ll still have a chance of snow for this period, but amounts would almost certainly be light. We`ll stay in generally north/northwest flow aloft through early next week with a high amplitude ridge centered just off the West Coast. That will support occasional shortwave troughs dropping southward across the Rockies through early next week. We`ll keep a chance of snow in the forecast for the weekend into early next week, as it will be difficult to time these disturbances in northwest flow aloft. Temperatures will also be colder and remain below normal levels, keeping the snow cover that we create tonight and Wednesday in place for quite some time to come. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 455 PM MST Tue Jan 17 2023 Moderate to heavy snowfall will lead to low visibilities at all terminals. It is likely by 02Z all terminals will decrease to IFR conditions. Winds will remain northerly through the entire period. Heavy snowfall could begin as early as 04Z at all terminals and continue through 08Z. Total snowfall amounts of 9-12 inches are expected at all sites. IFR conditions are likely between Wednesday afternoon and early Wednesday evening as this system moves east. Snow should subside by 00Z Wednesday. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 5 PM MST Wednesday for COZ031- 033>036. Winter Storm Warning until 5 PM MST Wednesday for COZ038>046- 048>051. Winter Weather Advisory until 11 AM MST Wednesday for COZ047. && $$ UPDATE...AD SHORT TERM...Rodriguez LONG TERM...Barjenbruch AVIATION...AD
Area Forecast Discussion
National Weather Service Charleston SC
939 PM EST Tue Jan 17 2023 .SYNOPSIS... A stationary front will linger in or near the area through Wednesday. A cold front will move through Thursday night, with a storm system to likely impact the region this weekend. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... This evening, KCLX detected a band of showers over the inland counties, drifting east. Sfc obs indicate that the rainfall is very light, supported by a dry layer observed from the sfc to H85 on the 0Z KCHS RAOB. Latest runs of the HRRR indicate that the band of showers will approach the coast around midnight, then dissipating. Based on radar trends and the latest HRRR, the forecast update will adjust hourly PoP/Wx. Temperatures remain on pace to reach the mid to upper 50s by daybreak Wednesday. Some guidance continues to suggest patchy to perhaps areas of fog developing across the region late tonight, mainly for locations inland where rainfall is anticipated during this evening. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... Wednesday and Wednesday night: A stationary front over or near the area initially will lift north as a warm front at night. High pressure extending east to west from the Atlantic across Florida into the Gulf of Mexico will still hold firm, as the next upstream frontal system moves that begins the period in the central and southern Plains moves into the Mississippi Valley and Tennessee Valley during Wednesday night. Short wave ridging with heights above climo aloft and strong warm advection will allow for temps that are far above normal for this time of year. Thursday and Thursday night: A solid mid level anticyclone holds firm over the Bahamas and Cuba, while a closed low lifts through the Great Lakes. A 150 kt upper level jet south of this cyclone will drive a cold front toward the area Thursday, eventually pushing it offshore at night. 850 mb temps as high as 12-13C, the 1000-850 mb thickness to expand to 1385-1390 meters and compressional heating in advance of the cold front on Thursday will push temps close to record levels (see CLIMATE below). It`ll also be a breezy if not windy day, with 30-35 kt low level jet to move through. With an additional boost from the sea breeze over the coastal corridor, south-southwest winds will peak at 15-25 mph, with gusts pushing 30 mph. Probably not enough for a Wind Advisory, but it might be enough for a Lake Wind Advisory for gusts near and along the shoreline. A band of upstream convection will approach Thursday, but with the upper support to weaken and only weak isentropic ascent, it`s likely that the convection will wane as it draws closer. thus we don`t have anything more than isolated to scattered PoPs. Friday: While a closed low drops through the Four Corners region of the southwest, a zonal flow locally aloft and high pressure trying to nose in from the northwest will lead to dry conditions. The air mass is cooler behind the front, but with a Pacific origin, it`ll still be above climo. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... The large scale pattern is quite progressive aloft, with the closed low to open into a short wave trough, as it looks to merge more with the northern branch where another short wave races through the northern tier of states. A mainly zonal flow prevails locally late week into the weekend, as a surface low pressure system develops over Texas within the right entrance region of the upper level jet. As the low pressure system progresses eastward across the Deep South, a moist airmass will overtake the local forecast area, likely resulting in an increase in rain chances from late Saturday into Sunday as an associated surface frontal system impacts the area. At this stage its hard to say whether or not we`ll be warm sectored with some t-storm potential, or whether it`ll be a more southern track of any surface low to keep us "cooler" and with more rain rather than convective elements. Either way there should be less rain chances Monday, with some concern that yet another system could approach Tuesday. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Prior to the 0Z TAFs, KCLX detected patches of light rain approaching the terminals from the west. A period or two of light rainfall is possible at each terminal, especially KCHS and KJZI late this evening. With the arrival of the showers, ceilings are expected to gradually lower, reaching MVFR by midnight at KCHS/KJZI and an hour to two later at KSAV. MOS and forecast soundings indicate the ceilings will continue to lower through the night. Reaching at least IFR during the pre-dawn hours. Restrictive ceilings are forecast to linger through Wednesday morning, becoming VFR during the early afternoon. Extended Aviation Outlook: Windy conditions at the terminals Thursday ahead of a cold front. Flight restrictions possible in association with a frontal system Saturday night and Sunday, mainly in rain, low ceilings/visibilities. && .MARINE... Tonight: High pressure will remain south-southeast of the waters while a front stalls northwest and inland. A modest pressure gradient will remain between the two features while a few showers attempt to drift over the coastal waters during the first half of the night. Expect conditions to remain below Small Craft Advisory levels across all local waters, but southwest winds should remain elevated, generally ranging between 15-20 kt overnight. A few wind gusts up to 25 kt remain possible near 20 nm off the Charleston County coast, but the duration is not expected to be sufficient for a Small Craft Advisory. Seas will range between 2-4 ft across waters to 3-5 ft across offshore Georgia waters. Wednesday and Wednesday night: The main synoptic feature that impacts the waters will be high pressure to the south, leading to S and SW winds no more than about 10 or 15 kt, with seas no more than 3 or 4 feet. While conditions are not ideal, given an abnormally warm air mass, and a period where winds could be somewhat favorable, we have added mention of patchy fog over the shelf waters Wednesday night. Thursday and Thursday night: Although we`re in a warm advection pattern between high pressure to the south-southeast and cold front approaching from the west and northwest, given the strength of the low level winds and a tightened gradient, conditions look more favorable for Small Craft Advisories. SW winds will climb to 20 or 25 kt with stronger gusts. Soundings actually indicate some gusts approaching gales at times on AMZ350. Friday through Sunday: Continental high pressure builds in late week, but gives way to a frontal system Saturday night and Sunday. Winds will be shifting through the period, but with speeds no more than 15 kt and gusty, while seas will hold below 4 or 5 feet. Thus no Small Craft Advisories are expected. && .CLIMATE... Record maximum temperatures for January 19th... KCHS: 78F degrees set in 1950 and previous KSAV: 79F degrees set in 2017 and previous KCXM: 77F degrees set in 1950 and previous && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...NED SHORT TERM... LONG TERM... AVIATION...NED MARINE...DPB CLIMATE...
Area Forecast Discussion
National Weather Service Cheyenne WY
448 PM MST Tue Jan 17 2023 .SHORT TERM...(Late this afternoon through Thursday night) Issued at 315 PM MST Tue Jan 17 2023 Afternoon GOES-W IR/VIS imagery showed the primary upper level low pressure center along the UT/AZ border. Copious Pacific moisture was streaming north-northeast into WY/CO/NE. A surface low was organizing across western CO, with a front trailing south into western NM. Precipitation was increasing in coverage in advance of the upper low from eastern UT to the I-25 corridor in CO. Skies were mostly cloudy to cloudy, with low stratus and patchy fog lingering over the northern NE Panhandle. Temperatures were 5 to 10 degrees cooler compared to Monday with readings in the mid 20s to mid 30s. A weak surface trough along the Laramie Range separated easterly winds from westerly winds. The primary concerns with the next 24 to 48 hours will be snow accumulations tonight through Wednesday with the winter storm and gusty winds on the backside of the exiting upper low. Model ensembles (ala SREF plumes) and associated QPF/snow totals have increased since the 06Z WPC guidance, and trended slightly northward with the heavier snow totals. The upper low tracks east across the Four Corners through this evening, and through southeast CO/western KS Wednesday morning. This will strengthen the surface low pressure system over eastern CO overnight. The GFS has slowed the progress of the low with the ECMWF a bit faster. Favoring the HRRR with the overall placement of the heavier snowfall, which has trended slightly more north. At this time, upwards of 8 to 12 inches with locally higher amounts is expected over the southern half of the NE Panhandle into far southeast WY. Along the I-25 corridor from south of Douglas to the CO border, 4 to 8 inches is expected. Winter Storm Warnings were expanded west from Cheyenne to the I-80 Summit. Winter Weather Advisories were issued for the Laramie Valley (2 to 5 inches), and North Laramie, Snowy and Sierra Madre Ranges (5 to 10 inches). No changes were made to the time period of the winter weather headlines (5 PM this afternoon to 5 PM Wednesday). The period of most impactful winter conditions is late this evening through late Wednesday morning. Snowfall rates 1-2 inches an hour are possible in the warned areas where banding develops. The snow will begin tapering off from west to east Wednesday afternoon. Despite the low visibility in falling snow and hazardous travel, winds are not forecast to increase until Wednesday afternoon, and especially Wednesday night and Thursday morning with stronger low level gradients on the backside of the departing upper low. Blowing/drifting snow will become a concern at that time. In fact, the in-house random forest high wind rise to near 60 percent between 09Z and 12Z Thursday at Arlington and the I-80 Summit. Probabilities are lower at Buford and Bordeaux. Peak gusts of 45-55 MPH are possible for these wind- prone areas. High temperatures Wednesday and Thursday will be below normal with mid 20s to mid 30s. After lows tonight in the teens and 20s, lows Wednesday night and Thursday night will drop into the upper single digits and teens. .LONG TERM...(Friday through Tuesday) Issued at 315 PM MST Tue Jan 17 2023 A change in the large scale weather pattern is expected for the long term period. The parade of Pacific troughs will come to an end, and transition to more north to northwest flow. We still expect regular shortwaves to impact the area, but these systems will likely be colder and drier than the pattern since late December. The first system will be a fairly vigorous but moisture starved upper level low diving down from the Pacific northwest from Thursday into Friday. A ridge will start to build in behind just off the West Coast, which will close the door to the abundant Pacific moisture most systems have tapped into for the last several weeks. The upper level low will track well into the desert Southwest, and is likely to be too far south for significant impacts to our area. The ECMWF and its ensemble has minimal precipitation for our area, while the GFS/GEFS brings some light precip to the I-80 corridor. Even in the higher end scenario, doesn`t look like more than a dusting to an inch or so. Kept PoPs in the 15-25% range along the I-80 corridor to have the mention of snow in the forecast, but this looks fairly minor. Unfortunately, it will also bring a little dose of arctic air. Models are in fairly good agreement on 700-mb temperatures dropping to around -12C behind this system. This supports a cold day on Friday, with highs struggling to get out of the 20s for many areas. Clouds will keep things cool on Friday, but then clear out Friday night and allow temps to dive further. Single digits and perhaps a few subzero readings are possible early Saturday. Transient ridging passes through on Saturday into early Sunday, so should see temperatures moderate towards near/slightly below normal. Models diverge somewhat on Sunday through the early part of next week, mainly regarding the timing and intensity of the next trough. The ECMWF depicts a faster, colder system with less precip, blowing through fairly quickly on Sunday and leaving quite cold air in its wake for Sunday into Monday. The GFS has a slower, warmer system passing through mainly on Monday. Due to timing uncertainty, kept a longer period of PoPs in the 20-40% range (slightly lower than NBM) from Sunday through early Tuesday. Overall, the forecast does not include any significant changes from previous updates. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 411 PM MST Tue Jan 17 2023 Flight conditions will deteriorate shortly after 00Z for the SE WY terminals as low-end VFR transitions to MVFR/IFR. Between 00Z and 12Z there will continue to be a shift as -SHSN move into the region and IFR/LIFR/MVFR fluctuations are likely for SE WY terminals. Winds are expected to be 15 knots or less through 12Z Wednesday, with gusts beginning to pick up closer to the 15Z-18Z timeframe for SE WY terminals. NE Panhandle will see a larger window of -SHSN impacting the area beginning later this evening through Wednesday. Low CIGs for KAIA and KCDR will remain present before all NE Panhandle terminals have low VIS and CIGs in the forecast period. All NE Panhandle terminals can expect IFR/LIFR overnight due to persistent -SHSN. Wind gusts are expected to be at or below 15 knots through the forecast period. Please see individual TAFs for further details on timelines. && .FIRE WEATHER... Issued at 315 PM MST Tue Jan 17 2023 No fire weather concerns are expected due to widespread snow Tuesday night and Wednesday. Moderate to heavy snow is expected across portions of Southeast Wyoming and the Nebraska Panhandle. Gusty northwest winds will produce some blowing snow Wednesday night and Thursday. Temperatures will remain below normal through the weekend. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Winter Weather Advisory until 5 PM MST Wednesday for WYZ101>103- 106>108-110-112-114-115. Winter Storm Warning until 5 PM MST Wednesday for WYZ116>119. NE...Winter Weather Advisory until 5 PM MST Wednesday for NEZ002-095- 096. Winter Storm Warning until 5 PM MST Wednesday for NEZ003-019>021- 054-055. && $$ SHORT TERM...MAJ LONG TERM...MN AVIATION...BW FIRE WEATHER...MAJ
Area Forecast Discussion
National Weather Service Dodge City KS
549 PM CST Tue Jan 17 2023 ...Updated Aviation Discussion... .SHORT TERM...(This evening through Wednesday night) Issued at 348 PM CST Tue Jan 17 2023 A significant winter storm system will be moving across the Central Plains through this Short Term period. The main forecast challenges for our west central and southwest Kansas areas will be precipitation type, amounts, duration and extent of dense fog, and timing of the end of precipitation on Wednesday behind the low. Early morning fog/freezing fog dissipated along/north of Highway 96 corridor, but is expected to redevelop and expand south/southwestward through the night before rain moves in. There is not much change in the overall thinking with respect to the rain forecast this evening through the night, as most of the forecast area should see 0.05 to 0.15 inch rainfall, locally higher. The rain within the warm conveyor belt (WCB) airstream of the mid-latitude cyclone will be moving east/northeast fairly quickly through the night. In the wake of the WCB rain axis, low level moisture will still be around with the surface low hanging around through Wednesday morning across west-central Kansas. Easterly low level, cool/moist upslope, east of the surface low, will favor development of fog (likely dense) beginning out west in the 06-09Z time frame and expanding in area through the morning hours. Dense fog is likely, and while a Dense Fog Advisory will not yet be issued on this shift, the evening shift will need to take a hard look at issuing one. As far as the winter component to this storm goes, the northern portion of the WCB precipitation shield later tonight will likely be wintry in nature. Winter precipitation chances will include some light freezing rain, especially up in the Scott-Lane-Trego County areas where temperatures at the surface will be right at or slightly below 32F with warm layer aloft maximum temperatures in the +2 to +3C territory. The best probability for snow, within the initial WCB precipitation axis late tonight, will be up north across northwest Kansas, north of our forecast area. On Wednesday, the cyclone will be fully occluded with a substantial "comma head" precipitation shield in the cold sector, west/northwest of the upper low track. The upper low track has shifted ever so slightly farther south in the latest model runs, such that some of the comma-head cold sector precipitation (snow) shield will likely extend farther south into west central and perhaps even southwest Kansas. The latest 18Z run of the HRRR shows a formidable shift south in the comma-head extension down into west central Kansas. Thus, will be keeping snow in the forecast through Wednesday morning and into the afternoon hours. We will still be keeping one-half to one inch of snow going, but this gradient of light accumulation to no snow at all may need to be shifted a bit farther south than even this latest forecast. Light snow may likely continue into the early evening up around Hays. In addition, strong northwest winds immediately west of the low, especially late Wednesday will be a factor as speeds will likely be 25 to 35 mph sustained for at least a few hours with gusts perhaps 45 to 50 mph. .LONG TERM...(Thursday through Tuesday) Issued at 348 PM CST Tue Jan 17 2023 Two more storm systems will be impacting the Central CONUS during this Long Term period. It now appears the first of these two, Saturday, may be coming out as a more coherent upper low (and farther south than this current storm), supporting better precipitation chances. The lower troposphere will be a bit colder initially, so the most likely precipitation type for most of the forecast area would be snow. If this storm tracks across the Texas Panhandle and remains a coherent closed low, then some portions of southwest Kansas will stand the chance at a 3-inch snowfall. This is something we will continue to fine-tune in the forecast over the coming days, especially once we finish up with tonight/Wednesday`s storm. Immediately on the heels of the Saturday storm will be northerly jet streak diving down the Rockies, forming a weak upper low down across New Mexico. This particular storm would dive well to our south before carving out an upper low some time Monday. All southwest Kansas would likely get from this type of setup would be a few hours of snow chance along the mid level frontal zone itself as it moves quite rapidly southeast late Sunday Night/early Monday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 531 PM CST Tue Jan 17 2023 Main item of interest will be LIFR conditions developing overnight BUFR soundings, boundary layer moisture/winds from the CAMS and HREF were all in good agreement with ceilings falling below 300ft AGL overnight as dense fog develops north of a surface boundary which will be located south of the Dodge City and Garden City area overnight. The east southeasterly winds at 10 to 15 knots north of this boundary will result in increasing low level moisture. The Hays observation at 2330UTC was already reporting visibilities between 3 and 5 miles. Along with the LIFR conditions developing tonight...light rain/drizzle along will be possible after after after 03z in the Hays and Garden City areas. The light rain/drizzle will begin mix with/change over to light snow between 09z and 12z Wednesday in the Hays area. A period of light precipitation can not be ruled out for a few hours early Wednesday morning. Once the precipitation begins it is expected to continue through the day on Wednesday. Snow accumulations currently are expected to be less than one inch in the Hays area. && .PRELIMINARY POINT TEMPS/POPS... DDC 34 44 22 49 / 70 20 0 0 GCK 30 37 21 47 / 80 20 10 0 EHA 29 39 23 50 / 70 10 0 0 LBL 30 42 23 50 / 70 10 0 0 HYS 32 34 21 41 / 90 80 20 0 P28 41 53 26 50 / 80 40 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from midnight tonight to midnight CST Wednesday night for KSZ030-031-043-044. && $$ SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Burgert
Area Forecast Discussion
National Weather Service Des Moines IA
914 PM CST Tue Jan 17 2023 ...Updated for Wednesday`s Precipitation Trends and Headline Adjustment over Northern Iowa ... .UPDATE... Issued at 914 PM CST Tue Jan 17 2023 Watching incoming model data and have seen the 00z HRRR continue to show a slow down in the arrival of the precipitation by about 10 to 20 miles per model hour. The 00z NAM is generally similar in timing, but perhaps slightly slower over western Iowa as the precipitation axis elongates more east west. Lending credence to the idea of a slower precipitation arrival is the 21z RAP and its cross sections, which shows the low level saturation (stratus) with dry air atop of it tonight into early Wednesday morning. As warm air advection begins to push northward Wednesday, saturation will try to advance northward. However, it will be fighting the dry air despite strong vertical ascent (omega upwards of 20 microbars/s) through the morning hours. Eventually, saturation will occur as the stronger warm air advection and QG convergence arrives with a broad area of strong omega within the dendritic growth zone between 21z Wednesday and 3z Thursday. This is when the higher snowfall rates over an 1"/hour to perhaps approaching 2"/hour are likely to occur over northern Iowa to the transition zone around Highway 30 and I-80. Farther south, an elevated warm layer and surface temperatures near freezing will make the initial precipitation type a wintry mix of snow, freezing rain, and/or rain. This still seems on track. What can be seen of the 00z HREF seems overdone for freezing rain given the time of day, which lends itself to sensible heating, and that temperatures and wet bulbs will be near or just below 32 degrees. While there could still be light icing of a glaze to a few hundredths, impacts should be mitigated by the aforementioned factors. Given the slower arrival of snow over northern Iowa Wednesday afternoon, have delayed the winter storm warning over the northern three tiers of counties until 21z. The remainder of the headlines and forecast otherwise seems on track with additional refinements from the overnight shift forthcoming. && .SHORT TERM.../Tonight through Wednesday Night/ Issued at 253 PM CST Tue Jan 17 2023 Forecast Impacts for the week: ...Significant Storm Begins Wednesday ...Most snow north/mix central/south ...Rapid Onset and Lessening of Precip in the Evening ...Quiet Remainder of Period Confidence Short Term: Medium Complicated system arriving over the region early Wednesday morning with strong push of warm air advection precipitation and a wet, heavy snow forecast. Today we continue to struggle with warming as stratus deck has been maintained for all the day, with the exception of the weak ridging over the far western counties of Iowa into eastern Nebraska. Despite this sunshine, most of that area has warmed little but the far southwest, given the continued weak cold air advection being transported into the state. Tonight, typical overnight cooling will lead to lows in the upper teens in the far north to the upper 20s in the far southeast. The approaching system consists of two distinct H850 centers over Colorado at 00z tonight, both which have been attempting to merge in western Kansas by 12z Wednesday, then become a bit more elongated again as the low pivots into Iowa between 00 and 06z Thursday. The wobbling system appears to be modeled fairly well by the synoptic models at this point, which is a good thing. Unfortunately, the transition area from mix to mostly snow is still somewhat fluid, though our general thinking of an axis of heavier snow will develop from west central areas of Iowa to the north northeast as the system translates northeast still remains intact. Early Wednesday morning, temperatures over the south will remain below 32 and a period of light freezing rain/snow mix is expected through 18z. This should bring up to a tenth of an inch of ice for the first few hours with a period of tremendous lift (20 mu bars/sec) overcoming the mix ptype during the late morning and afternoon hours, which should push things back to snow as the column cools. Strong isentropic lift will swing north out of Kansas into southern and western Iowa, eastern Nebraska between 12 and 18z tomorrow. The resultant cooling aloft/lift will increase the thermal gradient from west central to northeast areas during the afternoon hours. Once the mix changes over to snow south central, a quick 2 to 4 inches will be possible along the I80 corridor from 20z through 02z. Farther north and northwest where the precipitation will be all snow, snowfall rates may approach 1 to 2 inches per hour from Highway 30 north to the Iowa Minnesota border during the afternoon and evening as the strong lift moves north. Soundings suggest some weakening stability between 625 and 550 mb over much of the area as the strong advection continues. This will help enhance snowfall rates in that area. The strong forcing/warm air advection/moisture transport will shift north of I80 from 00z through 06z. The bulk of the higher snow totals will occur in this area during the evening hours and late night hours. South of this area over central and southern sections, there is a good possibility of losing ice introduction after 02-03z which will bring a round of light freezing drizzle back into the picture through about 12z. As the H850/sfc low stretches into 2 centers again between 06z and 12z Thursday, cold air along with additional wrap around moisture will result in some left over light snow or flurries/light freezing drizzle on the back side of the storm. The many moving parts make this a difficult snowfall forecast for snow ratios, timing and translation of system movement, but as it stands right now, we still expect a 6 to 9 inch band over about the northwest half with 2 to 5 inches from southern to south central areas. The far southeast will escape most of the snow, though freezing drizzle and light ice amounts will be expected during the event. With the various timing differences of start time southwest and then the onslaught of heavier precipitation developing regionwide in the afternoon, we have added a WW.Y in the southwest at 12z; converted the WS.A to a warning for most of the western to northeast areas and kept the central to eastern counties in an advisory. Our areas of greatest uncertainty continue on the southern edge of the warning area. These areas may be upgraded later if snowfall amounts/coordination justify. Likewise, portions of the southeast may need an advisory as well. Temperatures Wednesday should top off in the upper 20s northwest to the mid 30s in the southeast. Impacts will be fast and furious; especially in the afternoon and evening hours as snowfall rates increase. It`s likely the morning commute will be impacted southwest with the afternoon and evening commute strongly impacted in central to west central and north travel during the evening and Thursday morning commute. Lows Wednesday night will drop to the lower 20s northwest to the lower 30s in the southeast. && .LONG TERM.../Thursday through Tuesday/ Issued at 253 PM CST Tue Jan 17 2023 Confidence: Medium As the system pulls out, wind gusts will increase on the backside to 20 to 25 kts at times from 18 to 00z Friday. This will cause some blowing snow and may impact travel over the north mainly; areas north of US 30 and east of I35 for that time period. For the end of the week into the weekend, the models are struggling with a weak wave tracking into Missouri and possibly southern Iowa. About 1/3 of the GEFs members provide some support of return moisture and accumulating snow into southern Iowa. Currently, we have a chance of precipitation Sunday into Monday. Highs Friday into the weekend will start in the 20s to lower 30s, warming to the mid to upper 30s in the southeast as sunshine warms areas where snow cover is lacking. Colder air will return later Monday into Tuesday. && .AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/ Issued at 549 PM CST Tue Jan 17 2023 MVFR and IFR ceilings will prevail overnight ahead of a low pressure system that will pass south of the state. Moisture will advance northward of the low into Iowa during the day Wednesday with snow bringing more widespread IFR or lower conditions from south to north. A rain/snow mix may occur at DSM and ALO before precipitation transitions to snow by late in the period. Conversely, warmer air at OTM will result in rain being the more common precipitation type by the afternoon. && .DMX WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 3 PM Wednesday to 9 AM CST Thursday for IAZ004>007-015>017-023>028. Winter Storm Warning from noon Wednesday to 9 AM CST Thursday for IAZ033>037-044>048-057-058-070. Winter Weather Advisory from noon Wednesday to 9 AM CST Thursday for IAZ038-039-049-050-059>062-071>073. Winter Weather Advisory from 6 AM Wednesday to 9 AM CST Thursday for IAZ081>083-092>094. && $$ UPDATE...Ansorge SHORT TERM...REV LONG TERM...REV AVIATION...Ansorge
National Weather Service Sioux Falls SD
506 PM CST Tue Jan 17 2023 .SHORT TERM...(This Evening through Thursday Afternoon) Issued at 410 PM CST Tue Jan 17 2023 KEY MESSAGES: 1. An impactful winter storm will bring heavy snow to portions of the area for Wednesday into early Thursday - with the greater risk of heavy snow being along and south of Interstate 90. 2. Quieter conditions return later on Thursday into the weekend with temperatures at or just below normal. TONIGHT: Calm before the storm with quiet conditions expected overnight. Weak surface high pressure builds into the region tonight, and this will bring light northerly winds and cooler temperatures. With weak cold air advection lows will drop into the teens to lower 20s. WEDNESDAY/THURSDAY: Still on track for a major winter storm to affect parts of the region for Wednesday into early Thursday. An upper level low over the Southern Rockies lifts to the northeast on Wednesday, being situated over the Upper Mississippi Valley by 12z on Thursday. At the surface, deepening low pressure tracks from eastern CO to eastern IA/western IL during the same time frame. Light snow is expected to develop through the MO River corridor toward 12Z on Wednesday, then expand slowly to the north and east through the day - this in response to increasing midlevel warm air advection and strengthening midlevel frontogenesis south of Interstate 90 as the upper level wave approaches. As forcing increases in the afternoon and evening, snowfall rates are expected to pick up, with hourly rates of 1 to 2 inches as supported by HREF ensembles. The HRRR and RAP hi-res models as well as some of the global models, have trended northward for the past few runs, bringing the heavier snow into the Interstate 90 corridor. Still, there is enough variation among models that there could be a fairly tight gradient along the northern edge of the heaviest snowfall. The highest confidence of greater than 6 inch amounts lies near and south of Interstate 90, with GEFS/ECMWF/GEPS keeping the highest probabilities through that area. The heaviest snowfall will occur through the MO River corridor during the day on Wednesday, then in areas from the I-90 corridor and southward for Wednesday evening. Lighter snow will then continue late Wednesday night into Thursday morning. At this point, total snowfall amounts through the entire event will range from around 6 inches roughly along a Gregory to Sioux Falls to Windom line (and it is along this gradient that confidence is lowest with regard to amounts as a change in storm track will could change these amounts), increasing upwards to 10 to 11 inches through the central and lower MO River corridor. North of these areas, amounts rapidly decrease. As the surface low draws closer on Wednesday evening and Wednesday night, an intensifying surface pressure gradient will result in increasing northerly winds, gusting around 30 mph during the night. This will result in areas of blowing snow. With all of the above in mind, A Winter Storm Warning was issued for south central SD, far southeastern SD, northwestern IA, and portions of southwestern MN. Along the northern edge of this area where snow amounts will be less, a Winter Weather Advisory was issued. With the upper level and surface low pulling only slowly eastward on Thursday, light snow may linger east of Interstate 29 through the morning hours. Northwesterly winds will remain rather gusty through the day, again bringing the threat of patchy blowing snow. Slightly cooler air will feed in behind the system with highs mostly low to mid 20s for Thursday afternoon. .LONG TERM...(Thursday Evening through Monday) Issued at 410 PM CST Tue Jan 17 2023 FRIDAY/SATURDAY: Friday remains cool with lighter winds as high pressure builds into the region. Temperatures then moderate a bit for Saturday as the high slides eastward and a southwesterly flow returns to the region. An upper level trough dives into the Northern Plains later on Saturday, though stronger southern stream energy remains to the south of our area - with most models keeping any precipitation through the Central Plains. SUNDAY/MONDAY: Model differences lend low confidence for the beginning of next week - especially later in the period - most apparent in the handling of an upper level trough over the western CONUS. In any event, no significant systems look to affect our area during that time frame. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 503 PM CST Tue Jan 17 2023 MVFR to IFR ceilings will become more common thru the evening hours, persisting thereafter thru the TAF period. Even larger aviation impact will come from incoming snow thru the day Wednesday. Snow should arrive into the MO River Valley by mid to late morning, and then into the I-29 corridor by mid to late afternoon. Snow will be heavy at times, particularly south of I-90 resulting in vsbys at or below 1/2 SM at times. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Winter Storm Warning from noon Wednesday to 6 AM CST Thursday for SDZ062-066-067. Winter Weather Advisory from 6 PM Wednesday to 6 AM CST Thursday for SDZ055-056. Winter Storm Warning from 6 AM Wednesday to 6 AM CST Thursday for SDZ050-063>065-068>071. Winter Weather Advisory from 6 AM Wednesday to 6 AM CST Thursday for SDZ057-058. Winter Weather Advisory from noon Wednesday to 6 AM CST Thursday for SDZ059>061. MN...Winter Storm Warning from noon Wednesday to 6 AM CST Thursday for MNZ098. Winter Weather Advisory from 6 PM Wednesday to 6 AM CST Thursday for MNZ071-072-080-097. Winter Storm Warning from 6 PM Wednesday to 6 AM CST Thursday for MNZ081-089-090. IA...Winter Storm Warning from noon Wednesday to 6 AM CST Thursday for IAZ001>003-012>014-020>022-031-032. NE...Winter Storm Warning from 6 AM Wednesday to 6 AM CST Thursday for NEZ013-014. && $$ SHORT TERM...JM LONG TERM...JM AVIATION...Kalin
For this long-term forecast discussion, the active weather pattern
looks to continue across the High Plains. However, there will be a
pattern shift towards the beginning of next week that will change the orientation of how the weather systems progress across our area, resulting in what should be a continue of colder weather with uncertainty on how the precipitation chances will play out. More on that later. To begin with Thursday, a reprieve from the wintry weather is forecast with shortwave ridging setting up over the Plains. However, don`t expect much of a warm-up with widespread snow cover anticipated. A new trough of low pressure will be forming just to our west at the same time, so it is possible there is a surge of warmer air that might sneak into areas along and south of US Highway 40. This could bring temperatures into the 40s, but again, this may be highly dependent on snow cover on top of how far north the warm surge advances. Forecast guidance differs on the warm air intrusion, so for now have hedged towards the colder solutions verifying. By Friday, the previously mentioned low pressure system forming to the west, around the four corners region, will begin its advancement to the east. It won`t be until late Friday that the system makes its presence felt across the High Plains as that is when the better lift arrives with the system. Cold temperatures look to remain in place, and in fact there might be a slight reinforcement of the colder air. Precipitable water readings won`t be as high for this system compared to the mid- week storm expected to hit tonight, only climbing into the 0.30-0.35" range. In addition, as the low pressure moves east, it will start to devolve from more of a closed low into a progressive positively tilted trough. Therefore, the lift for this system may not be as strong, which should result in a less impactful wintry event. In addition, forecast guidance seems a little uncertain on how to handle this system, which is resulting in a larger range of precipitation total solutions so the liquid and snow amounts for this Friday system are relatively uncertain. Current forecast will call for snow totals approaching an inch or so along and south of Highway 40, but this forecast could and likely will change a few times before this event happens. As far as timing goes, snow would begin Friday afternoon in eastern Colorado, and Friday evening east of the Colorado border. The snow should come to an end by noon on Saturday. Again, only minor impacts should be anticipated at this time but that message may change depending on how this system evolves and trends in forecast guidance. Behind this system, northwest flow should take shape which will help keep the cold air in place. Yet another upper level low will progress towards the region on Sunday, bringing another chance for some light snow. However, climatologically, a northwest flow low pressure system is not favorable for a significant snow event, and a decent amount of the times that this type of pattern happens, the snow remains along the Colorado Front Range. Forecast guidance disagrees on the location, timing, and movement of this system, but there does seem to be agreement that this system exists and deserves to be monitored. Overall, current feeling is this system might stay further west which would mean little to no impact in terms of wintry weather. What you can count on with this system is that a reinforcing shot of cold air is expected. Once this air moves in, expect high temperatures each day to hover around freezing/32 degrees for Monday and Tuesday. While temperatures look to remain below freezing, we currently do not anticipate a shot of "bitterly cold" air. Low temperatures may fall into the single digits, but the winds don`t appear very strong so based on the current forecast, we would avoid wind chills approaching advisory criteria (-15 F or colder). In other words, below normal temperatures are anticipated but this won`t be a brutally cold type event. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 408 PM MST Tue Jan 17 2023 Both terminals will see conditions IFR and lower through the forecast period fog ahead of an approaching storm will allow for ceilings below OVC010 and any fog transitioning to all snow by 06z Wednesday. Visibility mainly a mile or less, but briefly 2-3sm is possible. Winds for KGLD, easterly 15-30kts through 16z Wednesday, then becoming northerly 15-30kts. Winds for KMCK, east-northeast 15-30kts through 16z Wednesday, then north-northeast 15-25kts. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Dense Fog Advisory until 9 PM MST /10 PM CST/ this evening for KSZ001>003-013>015-027>029-041-042. Winter Storm Warning until 11 PM MST /midnight CST/ Wednesday for KSZ001>004-013-014. Winter Weather Advisory until 11 PM MST /midnight CST/ Wednesday for KSZ015-016-027>029-041-042. CO...Dense Fog Advisory until 9 PM MST this evening for COZ090>092. Winter Storm Warning until 11 PM MST Wednesday for COZ090-091. Winter Weather Advisory until 11 PM MST Wednesday for COZ092. NE...Dense Fog Advisory until 9 PM MST /10 PM CST/ this evening for NEZ079-080. Winter Storm Warning until 11 PM MST /midnight CST/ Wednesday for NEZ079>081. && $$ UPDATE...JN SHORT TERM...076 LONG TERM...RRH AVIATION...JN
Area Forecast Discussion
National Weather Service Jacksonville FL
856 PM EST Tue Jan 17 2023 ...New UPDATE... .UPDATE... Issued at 853 PM EST Tue Jan 17 2023 Little overall change in the forecast tonight. A couple of shortwave troughs are moving through southeast GA tonight. A weak surface boundary will sag southward to near the Altamaha River Basin but likely staying north of the region. Sky cover will continue to increase over southeast GA with a low end (20 percent) chance of a showers as the shortwave activity aloft moves through. The main concern/impact tonight will be patchy to areas of late night and early morning fog. Recent HRRR runs show a few showers mixed in with cloudiness over southeast GA tonight, and given the boundary layer flow will be up to 10 kt or even 15 kt through about 1-2 kft, the confidence in widespread dense fog over inland zones, from about Suwannee county northward through inland GA to Coffee and Jeff Davis counties, remain on the low side. However, still looks like some dense fog potential, so we have included areas of dense fog over a small area of inland southeast GA tonight and early Wednesday morning. Otherwise, little change in the overnight lows mainly in the 50s, compared to the cold 30s and 40s from Tuesday morning. On the marine forecast...latest model guidance, 00z JAX sounding and the VWP at JAX, supports about 15-20 kt southwest winds for the offshore waters, at least for the evening hours. After that the winds may subside a bit. So included SCEC headline for offshore waters tonight. Otherwise, minor changes to seas and wave periods rest tonight/early Wed morning. && .NEAR TERM... (Through Tonight) Issued at 154 PM EST Tue Jan 17 2023 The region is between high pressure to the southeast, and stalled frontal boundary across central GA this afternoon. The ridge will build back northwest over area Tonight, helping to erode the remainders of the frontal zone. A few showers will be possible late this afternoon and evening north of Alma, GA. A gradient in cloud cover will be across the region Tonight due to the frontal zone, with mainly cloudy skies over SE GA, and partly cloudy NE FL. Lows in the lower to middle 50s Tonight. Best low level moisture for fog will be well inland Tonight. && .SHORT TERM... (Wednesday through Saturday) Issued at 154 PM EST Tue Jan 17 2023 On Wednesday through Thursday, the high will be to the southeast, as another low pressure system approaches from the northwest. The cold front will reach the far inland counties late Thursday afternoon, with a few showers along it. An increase in clouds is expected with this system, but the high will act to hold much of the precipitation out of the forecast area. The front will weaken as it passes southeast across area Thursday night. While cloudy skies are expected along frontal zone, dry weather is expected through the night. The front will stall across central FL Friday, as high pressure builds to the northwest. The boundary will remain stalled just to the south Friday night as the high builds more toward the north. As low pressure gathers over the northwestern Gulf, the front will lift back north into the area as a warm front Saturday. Moisture will stream east along this boundary producing a chance for showers. Temperatures will continue to be above normal through Friday, then near Friday night into Saturday. Potential for a significant fog event Wednesday night, especially inland. && .LONG TERM... (Saturday through next Tuesday) Issued at 154 PM EST Tue Jan 17 2023 Models diverge in the long range with the handling of the frontal system. GFS lifts the warm front to the north Saturday night, putting the forecast area in the warm sector overnight into Sunday, while the ECMWF keeps the boundary a little further south. In both cases, models move cold front into region late Sunday, and stalls it through the early part of the week. The ECMWF brings another wave across area Monday night into Tuesday, whereas GFS is a weaker solution. At this time will favor a forecast that is largely wet through this period. However, if closer to GFS solution Saturday night into Sunday could have much of the area in dry and warm sector. Temperatures will also be somewhat in question this period, depending on the position of frontal boundaries. Current forecast puts the frontal boundary around the GA/FL line this period, so temperatures over SE GA will be near seasonal levels, but above for NE FL. && .AVIATION... (00Z TAFS) Issued at 700 PM EST Tue Jan 17 2023 VFR clouds continue this evening with winds decreasing to less than 10 kt from the southwest. Some smoke in the air from prescribed burns but at this time no VSBY restrictions are in the TAFs for this evening. An increase in low level clouds for early tonight but above MVFR criteria around 4-6 kft as a weak boundary approaches from the northwest and any light rain showers remain northwest of the TAF sites over south central GA. After midnight, further boundary layer cooling and the increase low level moisture may support further ceilings down to MVFR and potential IFR late tonight and early Wednesday morning. Some mix of low cloud and fog anticipated. For now, best chance of IFR CIGS/VSBYS are at GNV/VQQ/SSI and have placed TEMPO for these conds roughly from 09-15Z, while lower chances at other TAF sites, so have gone just with MVFR conds in the 10-13Z range at JAX/CRG. Conditions should improve in the 15Z-18Z range (except later for SSI), with prevailing VFR returning to the TAFs. Light southwest winds Wed morning, becoming a bit more southeast at SSI, CRG, and SGJ Wed afternoon due to the Atlantic sea breeze. && .MARINE... Issued at 154 PM EST Tue Jan 17 2023 High pressure will be southeast of the region through Thursday. A cold front will move southeast into the region and weaken Thursday afternoon through Thursday night. The front will stall across central FL Friday into Friday night, while high pressure builds from the northwest. This boundary will lift north across the area as a warm front over the weekend, while moisture moves east along it. A cold front will move southeast across the area Sunday night. Rip Current Risk: Moderate through Tuesday && .PRELIMINARY POINT TEMPS/POPS... AMG 57 76 57 79 / 10 20 0 10 SSI 57 70 56 74 / 0 10 0 0 JAX 53 77 55 80 / 0 0 0 0 SGJ 55 75 57 79 / 0 0 0 0 GNV 51 77 53 79 / 0 0 0 0 OCF 51 77 53 80 / 0 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
858 PM EST Tue Jan 17 2023 .SYNOPSIS... Weak high pressure will build overhead tonight into Wednesday. Low pressure will track from the central CONUS into the Great Lakes Thursday through Thursday night and the cold front associated with the low will pass through our area Thursday night. High pressure will build overhead late in the week before low pressure possibly impacts the area later in the weekend. && .NEAR TERM /THROUGH WEDNESDAY/... Patchy dense fog has developed in areas around the Capital Beltway this evening especially north of I-66 and US-50. Almost issued a Dense Fog Advisory, but visibility has been bouncing a lot recently. In addition, scattered showers have developed across western MD and the eastern WV panhandle along a weak frontal zone. Latest HRRR has these showers moving across northern MD north of I-70 through midnight. Latest Metar plots, satellite imagery and model data show that any fog should dissipate around 06Z. Given patchy nature and bouncing visibility will hold off on issuing any Dense Fog Advisories. Previous afd... Will also monitor wind gusts over the Allegheny Highlands late tonight. West to northwest winds will gust around 40 to 45 mph, and some gusts around 50 mph are possible. Confidence was too low for an advisory at this time since the pressure surge and cold advection behind a cold front will be weak. However, there are strong winds (around 50 knots) near the top of the mixing layer. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... Weak high pressure will build overhead Wednesday, and a surface boundary will remain stalled nearby. However, some sunshine, downsloping, and an increased mixing layer will cause more unseasonably mild conditions, with highs in the 50s and 60s for most areas (40s in the mountains). Low pressure will track from the central CONUS Wednesday night into the Great Lakes Thursday, and into New England Thursday night. As the low pressure tracks through the central CONUS Wednesday night, this will strengthen the thermal gradient along a stalled boundary over our area. The strengthening gradient combined with isentropic lift will likely cause rain to overspread the area, especially overnight. More showers are expected Thursday as the low pressure passes by to the north, and the cold front associated with it approaches from the west. A nearly stationary boundary will remain over the area ahead of the approaching cold front, separating a mild southerly flow from cooler marine air. Therefore, a large temperature gradient is expected with 60s for high temperatures most likely south of the boundary and 40s most likely north of the boundary. The cold front will pass through Thursday night, and some showers are possible ahead of the boundary. A stronger pressure surge behind the cold front will bring blustery and chillier conditions late Thursday night. Upslope snow showers are likely along and west of the Allegheny Front, and some showers may even spill east of the mountains. Accumulations will most likely be light, with up to an inch by daybreak Friday. Strong winds are progged to be over the higher elevations as well. Some gusts around 50 mph are possible in the Allegheny Highlands. Elsewhere, winds should be weaker, but still gusty. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As an area of low pressure exits the forecast area to our north, upslope snow showers are likely along the Allegheny front. Snow showers should last all day on Friday and persist through Saturday morning along the Allegheny front with the rest of the area staying dry. Conditions will be breezy on Friday with high temperatures in the 40s and 50s (30s at higher elevations.) Wind gusts of 40-50mph are possible at higher elevations Friday. High pressure will build over the area on Saturday with seasonable and dry conditions expected. Rain returns on Sunday as the next system approaches the forecast area. There still remains a good bit of model discrepancy surrounding the overall synoptic pattern for Sunday into Monday leading to uncertainty surrounding precipitation type. Precipitation could move into the area beginning Sunday morning with widespread rain likely during the day. There is a chance of wintry precipitation Sunday night into Monday. We will continue to monitor this system as there is a good bit of uncertainty with it being too far out. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... IFR cigs/vsby restrictions are likely through 06Z across the main terminals. Conditions should improve after 06Z as weak cold front passes through the area. should gradually burn off during the overnight as the cold advection becomes a bit stronger and the gradient strengthens. VFR conditions are expected for Wednesday with west to northwest winds gusting around 15 to 20 knots (mainly late morning and afternoon). Winds will diminish Wednesday night. Rain chances will increase Wednesday night into Thursday with more IFR/subIFR conditions possible. Drier air will return late Thursday night. VFR conditions are expected Friday and Saturday. && .MARINE... A south to southwest flow will continue through this evening before turning west to northwest late tonight through Wednesday morning. An SCA is in effect for portions of the Bay and lower Tidal Potomac below Cobb Point and Drum Point, but winds should remain below SCA levels for most of the waters. An SCA is in effect for the northern Bay and upper Tidal Potomac River late Wednesday morning/afternoon for west to northwest winds. Winds will diminish Wednesday night with the loss of mixing. Low pressure will approach the waters Thursday and the cold front associated with the low will pass through Thursday night. An SCA may be needed for portions of the waters during this time. Westerly winds on Friday will likely be above SCA criteria. Winds are expected to diminish Friday night and into Saturday and will likely be below SCA criteria. && .TIDES/COASTAL FLOODING... A south to southwest flow will keep anomalies around 1 to 2 feet above normal through this evening. Minor flooding is expected around high tide across Washington DC, and the western shore of the northern Chesapeake Bay late this afternoon into early this evening. Tidal anomalies should fall later tonight into Wednesday as an offshore flow develops. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...Dense Fog Advisory until 1 AM EST Wednesday for DCZ001. MD...Dense Fog Advisory until 1 AM EST Wednesday for MDZ013-503>506. VA...Dense Fog Advisory until 1 AM EST Wednesday for VAZ052>054-506. WV...None. MARINE...Small Craft Advisory from 9 AM to 6 PM EST Wednesday for ANZ530>532-535-538-540. Small Craft Advisory until 6 AM EST Wednesday for ANZ534-537- 543. && $$ SYNOPSIS...BJL NEAR TERM...LFR SHORT TERM...BJL LONG TERM...AVS AVIATION...AVS/LFR MARINE...AVS/LFR TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Memphis TN
927 PM CST Tue Jan 17 2023 ...New UPDATE... .UPDATE... Issued at 927 PM CST Tue Jan 17 2023 Weather conditions are quiet across the Mid-South as of 9 PM CST, but changes are on the way for tomorrow. We presently have patchy fog affecting portions of north MS and southwest TN with localized visibility reductions of less than 1 mile. We don`t think this fog will stick around too long given the increasing mid/high clouds and anticipated uptick in southerly flow later tonight. A strong mid-latitude cyclone is moving slowly east across the Four Corners this evening with strong, diffluent southwesterly flow aloft over the Southern Plains. Strong forcing for ascent is noted via water vapor and this will overspread the Mid-South late tonight into early Wednesday. We may begin to see light warm advection showers by 10-12z with some developing low clouds. Rain chances will ramp up quickly from west to east Wednesday morning as the warm advection strengthens with a warm front lifting north toward the KY/MO state lines. Isentropic ascent will be quite focused during the 12-18z timeframe, resulting in fairly widespread rain with embedded convective elements. While this could limit instability during the afternoon period, the strong warm advection/moisture transport are expected to offset this, at least to some degree. Instability remains the primary question mark for tomorrow`s severe weather potential. We do anticipate storms lining up into a QLCS by 00z and marching across the CWA throughout the evening. Total QPF looks to be 0.75" to 1.5" with localized amounts exceeding 2.0". Most of the 00z CAMs are offering 300-500 J/kg of MLCAPE with the HRRR being the most aggressive. Given the strong kinematics, this would be sufficient to support a damaging wind threat that wanes as the line approaches the TN River and AL state line. We do often see a low bias in guidance instability in these high shear-low CAPE setups so that adds some confidence. Strong low-level storm- relative helicity suggests the potential for mesovortices should updrafts be strong enough and the convective line balanced. This would provide a least a mentionable threat for brief, spin-up tornadoes. This doesn`t differ much from this afternoon`s thinking. The final thing to mention is that a Wind Advisory may be needed for some areas late tomorrow afternoon and evening as southerly winds ramp up to 20-25 mph with gusts over 35 mph at times, especially east of the MS River. MJ && .SYNOPSIS... Issued at 218 PM CST Tue Jan 17 2023 The Sun may peek through the clouds over the next few hours before clouds move back into the region. By tomorrow afternoon, an approaching cold front will result in shower and thunderstorm development, with a few becoming strong to severe. The main threat for this event will be damaging winds and isolated flooding, with urban and small streams most vulnerable. However, small hail and a brief tornado or two cannot be ruled out. Once the cold front moves through the region, cool and dry conditions are expected through the weekend. The next chance for rain will be Sunday through Monday. Otherwise, the beginning of next week will be cool with high temperatures in the low to mid 50s. && .DISCUSSION... (This evening through next Monday) Issued at 218 PM CST Tue Jan 17 2023 A few peeks of sunshine are present this afternoon as clouds associated with Monday`s system continue to retreat out of the region. As a result, the Mid-South could see increased amounts of sun for the next few hours before additional cloud cover rolls in this evening. In addition, temperatures will remain above normal overnight as increased clouds inhibit radiational cooling. Overnight lows in the mid to upper 50s are expected. Elsewhere in CONUS, an upper level trough is situated just west of the Rockies. As this system pushes eastward, an upper-level low with an occluded cold front will emerge and impact the Mid-South Wednesday. Ahead of the front, rapid moisture advection from the Gulf of Mexico is expected across the region. As a result, dewpoint temperatures in the mid 60s are expected along with PWAT values of 1.5", which is above the 99th percentile for this time of year. This, combined with the approaching cold front, will result in shower and thunderstorm development by Wednesday afternoon. The kinematics associated with this system remain favorable as 0-6km shear values of 60-70kts are expected across the Mid-South. However, instability remains an unknown as recent model runs have trended towards more disagreement. For example, the CAMs are showing much higher CAPE values with the 18Z HRRR painting a swath of 600-800 J/kg across portions of north Mississippi. Recent Ensemble runs have had slight changes, but the overall probability of >500 J/kg of CAPE remains at 10-20%. Regardless, the main threat with this system will be damaging winds with small hail and a brief tornado or two possible. Originally, lapse rates were not supportive of strong updraft ascent. However, latest model runs are showing an increase in values to around 7 C/km. If this trend continues, hail could become a bigger threat. Isolated flooding is also a primary threat as the aforementioned PWAT values aid in heavy rainfall production, with forecast totals of 2-3" possible across the region. In addition, recent rains have resulted in soil saturations of >50% across the entire Mid- South. This combined with several streams and rivers reaching flood stage last week could result in a flash flooding potential. However, the biggest threat will be urban and small stream flooding. Once the cold front moves through on Wednesday, northwesterly winds will allow for cool and dry conditions through the end of the week. By Friday, zonal flow will return to the region and allow for winds to switch to a southeast direction by Saturday. Once this happens, moisture advection will allow for PWAT values of about 1.0" to return to the Mid-South. This will result in an increase in precipitation chances by Sunday. The beginning of next week will be dry with highs in the low 50s. ANS && .AVIATION... (00Z TAFS) Issued at 510 PM CST Tue Jan 17 2023 VFR conditions will continue through most of the overnight hours. Low clouds will start to move into the Mid-South by early Wednesday morning producing LIFR/IFR ceilings. Some areas of fog may develop overnight but confidence is low that it will effect any of the TAF sites at this time. Showers and thunderstorms will begin to move into eastern Arkansas Wednesday morning and then spread across most of the region during the late morning and afternoon hours. Winds will be light and variable this evening before shifting to the southeast and increasing to 10 to 15 knots with higher gusts by Wednesday afternoon. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ UPDATE...MJ PUBLIC FORECAST...ANS AVIATION...ARS
Area Forecast Discussion
National Weather Service Medford OR
436 PM PST Tue Jan 17 2023 .UPDATE...Updated aviation discussion for 00z TAFs. && DISCUSSION...The latest visible satellite image shows mostly clear skies, except for varying amounts of low and mid level clouds west ofthe Cascades in association with a weak warm front moving into the area. The warm front itself is not expected to produce much, if any precipitation. However could not rule out a trace to a hundredth or two of precipitation north of Cape Blanco this evening. The main concern in the forecast period will be late tonight into Wednesday. Details on this to follow below. There`s good agreement a stronger cold front will arrive at the coast shortly after daybreak Wednesday and move inland during the morning and afternoon hours. Along and just ahead of the front, there could be a 3-6 hour period of moderate to occasionally heavy precipitation. The one concern we have will be the potential for snow levels to lower close to Hay`s Hill Summit and the other summits north of Grants Pass on I-5 during the time of when precipitation is heaviest (which is expected to be from late morning into the afternoon hours) This is due in part to the heavier precipitation allowing the colder air aloft to be drawn down near the surface in these areas. Given precipitation will be coming in later in the morning Wednesday, this should put a cap on the amount of accumulating snow due to warming roads. However if skies remain clear to mostly clear to start the evening, before clouds increase tonight ahead of the Wednesday`s front, temperatures may be slow to rise during the morning hours Wednesday, thus raising the concern for snow to stick on the roads for the above mentioned areas. With that said, confidence on all of this remains low mostly because everything just mentioned will need to line up perfectly. The second concern will be the potential for snowfall rates to exceed an inch per hour late Wednesday morning into Wednesday afternoon along the Cascades. Some of the high res guidance suggest there`s a 70-90 percent chance of this happening. It`s for this reason a Winter Weather Advisory has been issued to include the Cascades and portions of the Siskiyous. This is in addition to the one that had been issued earlier for portions of Siskiyou County. Please see WSWMFR for more details. Wednesday the front will move from northwest to southeast with steady precipitation becoming scattered as post frontal showers follow the front as the upper trough approachers the area late Wednesday afternoon. Showers continue into Wednesday night as the upper trough axis moves overhead, but should gradually diminish late Wednesday night from west to east as the trough axis also shifts east. A cold air mass will move into the waters Wednesday afternoon with 500 mb temperatures between -30 and -35 C. Therefore isolated thunderstorms are possible over the entire marine waters, along the coast and inland into portions of Coos, Curry and northwest Douglas County Wednesday afternoon and early Wednesday evening. Thursday, a few showers could linger along the Cascades and north of the Umpqua Divide in the morning, then it will be dry in the afternoon. Temperatures for most inland locations will be cold to start and cool in the afternoon. -Petrucelli LONG TERM...Thursday night, Jan 19 through Tuesday, Jan 24, 2023...Confidence in the overall weather pattern is high as we`ll see an upper level ridge develop and persist for a while near or just off the West Coast. This will mean a quiet weather pattern with temperatures averaging near to below normal, but with below normal overnight lows, especially east of the Cascades. Precipitation will be below normal in all areas. A couple of weak fronts will move over the top of the ridge (one on Saturday and another Mon night or Tuesday), but precipitation chances will be minimal and confined to areas along the coast and in northern Douglas County. Periods of stagnant conditions are possible during this stretch of calmer days, but soundings at this range show that those periods probably are not long-lived enough for advisories at this time. The coldest night is likely Thursday night with the combination of upper ridging, a developing subsidence inversion and weakening northerly flow aloft. This will allow temperatures to drop quickly in the evening east of the Cascades with lows in many areas of 0 to 10F above. West of the Cascades, this will probably be the coldest night in a month (since the cold stretch of mid-December). Confidence is a bit lower with respect to temperatures though since there probably will be some low clouds and fog to contend with. But, areas that stay clear most of the night will get into the 20s to low 30s. Frost is probable (>60% chance) for areas along the coast. An upper ridge axis will move overhead Friday, then, after Saturday`s weak front, the upper ridge offshore will amplify Sunday into Monday. While we do expect some low clouds and fog to form beneath the inversion at times in the valleys especially west of the Cascades, low-level offshore flow could limit the areal coverage and extent. Temperatures during this time should moderate a bit compared to the late-week cold. -Spilde AVIATION...18/00Z TAFs...A weak disturbance is bringing a band of rain/snow across the area and could produce MVFR ceilings. Lowered ceiling s behind the band is causing MVFR conditions along the coast and over the coastal waters along with isolated showers/drizzle possible. Later tonight into Wednesday morning, more widespread MVFR conditions and precipitation are likely to develop along the coast and over portions of the West Side as the next front approaches the area. Terrain will become obscured. Low level wind shear could be an issue at North Bend for a few hours overnight before winds surface. Precipitation will reach the Cascades by early afternoon, including at Medford, then push over to the East Side in the afternoon. When the front pushes over to the East Side, an airport weather warning may be needed at KLMT as there is 30-40% chance to reach the 1" snowfall criteria starting around 10AM. -Miles MARINE...Updated 200 PM PST Tuesday, January 17th 2023...West swell dominated seas will remain high and steep into this evening. The next cold front arrives late tonight into Wednesday morning. We expect a period of gusty south winds and steep seas ahead of the front, with a short period of gales expected as the front passes Wednesday morning. The strongest winds are expected north of Cape Blanco, with the HRRR model indicating a peak between 3 AM and 6 AM Wednesday morning. Winds shift to northwest and ease Wednesday afternoon, but high and steep west swell will continue through Thursday evening. Conditions are expected to improve late Thursday night through Friday. -CZS && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Winter Weather Advisory from 10 AM to 7 PM PST Wednesday for ORZ025-027-028. CA...Winter Weather Advisory from 10 AM to 10 PM PST Wednesday above 2500 feet for CAZ080>083. PACIFIC COASTAL WATERS...Small Craft Advisory until 10 PM PST Thursday for PZZ350-356-370-376. Gale Warning from 4 AM to 10 AM PST Wednesday for PZZ350-356-370- 376. && $$
Area Forecast Discussion
National Weather Service Norman OK
522 PM CST Tue Jan 17 2023 ...New AVIATION... .SHORT TERM... (This evening through Wednesday) Issued at 342 PM CST Tue Jan 17 2023 A shortwave trough currently digging across the southwestern U.S. will be moving across the Southern Plains this evening through Wednesday, with all deterministic models tracking the upper low across Colorado into the Central Plains. This system will bring widespread chances for rain across our area while mid-level lapse rates may steepen across southeast Oklahoma for some weak elevated convection overnight. Meanwhile ahead of this approaching wave, increasing southwest flow aloft will continue to transport Pacific- based moisture through the mid to upper levels as fuel for our initial rainfall. HREF members start precipitation early this evening. Both NAM & RAP guidance in good agreement with isentropic upglide in the mid-levels across our west beginning this evening. Will start rain POPs early this evening across our west and increase them spatially into the early morning hours. The strongest mid- level ascent may be just after midnight, so ramped up rain POPs and making them more widespread across our entire area, with the highest POPs across our north which is closer to the upper low. A low-level jet will develop tonight south and east of I-44 transporting additional gulf-based moisture with the lower-levels moistening up there, while southeast and eastcentral portions of Oklahoma may destabilize for a few weak thunderstorms into the mid-morning hours of Wednesday as the jet strengthens there. After sunrise, expecting POPs to decrease from west to east as the morning progresses, and to the east out of our area by noontime. The nearly vertically stacked surface low moving across the Central Plains (Kansas) will shift our winds southwest during the afternoon, while the tight pressure gradient will keep it windy. Vertical mixing into the 925-850 mb flow could produce some 30-40 mph wind gusts. Will see our winds gradually veering as a cold front starts pushing through toward the evening hours. However ahead of the cold front, dry air coming up from the western half of Texas combined with gusty winds and dry fuels may increase the fire weather danger across our south and west. The fire danger risk will be Near Critical Wednesday afternoon across western north Texas, where a Fire Weather Watch remains in effect. The fire danger risk will be Elevated across western and southcentral Oklahoma as well on Wednesday afternoon. && .LONG TERM... (Wednesday night through next Monday) Issued at 342 PM CST Tue Jan 17 2023 The aforementioned cold front continues to push across our area Wednesday night. Although a Pacific-based front, it will tap into some colder Canadian air already in place across the Northern/Central Plains with a cooling trend. Areas north and west of I-44 expected to drop below freezing Wednesday night, to near freezing across our remaining areas. We`ll see more seasonably average temperatures on Thursday although a return of south winds on Friday will result in a short warming trend. Our next upper trough comes through this weekend bringing a cold front through on Saturday. Northern Oklahoma may tap into more of that Canadian air with a chance of light snow early and late Saturday while the rest of our area could see more of a "cold" rain. Rain chances continue through the afternoon Saturday with seasonably average temperatures. Deterministic models diverge quite a bit for early next week with respect to precipitation and timing. The Canadian NH, GFS, and ECMWF are similar with a Canadian-based trough digging across the western U.S. with the ECMWF much faster and wetter into our area for Monday. Should the ECMWF play out, northwest Oklahoma could see snow again. However much uncertainty at this point so only have very low POPs (15%) for rain or snow across northwest Oklahoma for Monday. && .AVIATION... (00Z TAFS) Issued at 518 PM CST Tue Jan 17 2023 Rain chances will increase later tonight into early Wednesday morning, especially across central and northern OK. A few thunderstorms will also be possible mainly over/near PNC and SWO. Winds will become more southerly overnight and increase from the SW by late Wednesday morning. Gusts may exceed 30 kt at times. Skies will begin to clear from west to east after 18Z Wednesday and right now it appears cigs should remain VFR. This could change with the next (06Z) forecast. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 50 62 32 51 / 60 40 0 0 Hobart OK 44 61 31 53 / 60 20 0 0 Wichita Falls TX 51 66 35 56 / 40 20 0 0 Gage OK 38 57 26 53 / 60 0 0 0 Ponca City OK 48 61 29 48 / 90 60 0 0 Durant OK 55 68 38 56 / 40 40 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...Fire Weather Watch Wednesday afternoon for TXZ083>090. && $$ SHORT TERM...68 LONG TERM....68 AVIATION...03
Area Forecast Discussion...UPDATED
National Weather Service Pittsburgh PA
656 PM EST Tue Jan 17 2023 .SYNOPSIS... A passing cold front will return isolated to scattered rain showers through late evening. Widespread rain is projected to arrive early Thursday with the next low pressure system. && .NEAR TERM /THROUGH WEDNESDAY/... Only minor changes needed for the evening update. PoPs were modified to better represent current conditions and the latest hires model output. Cloud cover was also refreshed. Rest of the forecast in good shape. Previous discussion... A closed upper-level low over the Great Lakes will weaken and drift east early Wednesday morning and become an open wave. However, with weak shortwave activity embedded within the large scale disturbance and winds veering from the west to west- northwest, precipitation chances may still continue with additional lake enhanced moisture. Along with rain showers, sub- advisory wind gusts may evolve along the ridges. The NBM is pretty aggressive with gusts over 40kts, probabilities above 80 percent in eastern Tucker County. However, with saturation capped at a few hundred feet above the surface and limited dry air for elevated mixing, confidence even now on the blended outcome is not very high. Even Hi-Res soundings like the HRRR and NAM12km are suggesting lower gusts. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... For Thursday, a new low pressure system should return rain chances to the region. Warm frontal precip will lift into the area Thursday morning and with warm air already in place, should fall as rain. Warm frontal passage through the day on Thursday will leave the area in the warm sector with deterministic models hinting at some minimal instability. NBM trends indicate mid level warming to squelch the potential. This will need further monitored if thunder will need to be added in future forecast packages. Precip will likely change to snow showers early Friday morning with cold air advection as a post frontal trough combined with northwest flow engage in the region. Snowfall amounts will be limited to the an inch in the ridges with upsloping, a few tenths of an inch in the lower elevations. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... Generally dry weather should return Friday night and Saturday as a weak ridge builds across the Upper Ohio Valley region. Temperatures should return to more normal values for Friday night and Saturday. Another low pressure system is expected to develop over the weekend, advancing to the Central CONUS and Midwest region by Sunday. A surface low is also progged to develop along the Gulf Coast in response to the approaching trough, tracking northeastward on Sunday. Rain and snow chances should return for Sunday and Monday with the approach of this system, though plenty of uncertainty exists in the details that far out in the forecast. Two trends continue with this set up being the rather progressive pattern and slightly above normal temperatures. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... A brief period of VFR continues this evening before cigs lower into MVFR and eventual IFR once again overnight. A few isolated rain showers are expected through the evening hours, but coverage is low enough to warrant VCSH mention only. Westerly winds will gust 20-25kt through the morning, diminishing in the early afternoon. Brief ridging will allow improvement to MVFR and periods of low VFR Wednesday afternoon and evening. .OUTLOOK... Low pressure will cross the region on Thursday, leading to another round of rain and restrictions into the weekend. Changeover to light snow is expected on the backside of the system Friday into Saturday. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...Hefferan LONG TERM...Shallenberger AVIATION...Rackley
Area Forecast Discussion
National Weather Service Las Vegas NV
752 PM PST Tue Jan 17 2023 .SYNOPSIS...Dry and cooler air will move into the region Wednesday before a cold circulation dropping down from Canada brings the possibility of mountain snow and valley rain showers to portions of the forecast area Thursday. Temperatures are also forecast to be about 10 to 12 degrees below normal. More cold air may drop out of Canada into our region Sunday and Monday. && .UPDATE...Shower activity continues over the Spring Mountains and across Mohave Co this evening. Radar returns suggest mainly light showers but a few areas near Dolan Springs to Peach Springs and northward have some embedded moderate shower activity. The HRRR forecasts showers ending in the Spring Mountains by 9 pm but continuing in parts of Mohave County through midnight. We are not anticipating any significant rain or snowfall amounts with this activity. Otherwise, expect dry conditions through the night with cool temperatures and light winds. No forecast update this evening. && .PREV DISCUSSION...140 PM PST Tue Jan 17 2023... .SHORT TERM...Today through Thursday. With a little bit of afternoon heating we have started to see a few showers develop across portions of Lincoln, Clark, and Mohave Counties. Generally, these have been fairly light as they move southeast through the area. The more impactful precipitation has been occurring in the Spring Mountains where upslope precipitation has been occurring much of the day. Local SNOTELs where indicating between 3-5 inches of snow has fall this early this morning. Did go ahead and issue a Winter Weather Advisory until 6pm this evening for elevations above 7000 feet. Some lighter accumulations are possible at lower elevations, but is not expected to be as impactful. Most of the shower activity is expected to dissipate after sunset, but will likely linger into the later evening in northern Mohave which is closer to the low center. Quieter weather on tap for Wednesday as weak high pressure moves over the area bringing lighter winds along with dry conditions areawide. This is expected to be a short-lived break as another system will drop south out of western Canada and into Nevada late Wednesday and eventually form a closed low over southern Nevada early Thursday. Due to the trajectory of this system, it is not forecast to have as much precipitation, but it will be colder with snow levels down to around 3000 feet. Precipitation amounts look for be fairly light with most areas seeing less than a tenth of an inch, but snow amounts in the Spring Mountains could total around 3-5 inches along with the Hualapai in Mohave County. Even Kingman could see a little snow as latest NBM is giving them about a 25% chance of seeing at least 1 inch of new snow. Temperatures will be about 10 degrees below normal most areas with places like Las Vegas only reaching the upper 40s. .LONG TERM...Friday through next Monday. The aforementioned system will quickly exit the area Friday leaving behind dry and breezy conditions in its wake. Temperatures are forecast to be around 10 degrees below normal, so combine these temps with the winds it will free rather blustery. Starting Sunday, the models are in disagreement with the next low that is forecast to drop out of western Canada. The EC wants to push the eastern Pacific high further inland which in turn keeps to low well east and generally brings some cooler air and breezy north winds. The GFS and Canadian try and bring the low further west with the Pacific high not being quite as strong. Even the latest cluster analysis shows these differences and at this point confidence is low with any potential precipitation over the weekend. In either case, it does look like we will be in for a cooler than normal along with breezy northerly winds into early next week. && .AVIATION...For Harry Reid...20-25 knot west-northwesterly wind gusts will continue through the afternoon with sustained winds around 8-12 knots. Wind gusts will drop off around 02Z, with winds becoming more northwesterly. These northwesterly winds will continue through 18Z when winds will shift to the east-northeast. Cloud cover will continue to dissipate, with skies becoming clear later tomorrow morning. For the rest of southern Nevada, northwest Arizona and southeast California...Gusty northwesterly winds will continue at KVGT through 03Z. Gusts will drop off but winds will remain out of the northwest at 10-15 knots. Gusty northwesterly winds will continue at KHND through 02Z when wind gusts will drop off and winds become more west- northwesterly. Northwesterly wind gusts will continue at KBIH through 02Z when gusts will drop off while 6-10 knot sustained northwesterly winds continue. Gusty westerly winds will continue at KDAG through later this evening. Around 01Z wind gusts will drop off with 10-15 knot sustained westerlies continuing through the evening. KEED will favor a westerly direction through 01Z when winds will become more west-northwesterly. Sustained wind speeds will be between 7-12 knots, with gusts possible this afternoon. KIFP will remain relatively light, 10 knots or less, while favoring a southeasterly direction with the occasional period of more variable winds. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ UPDATE...Salmen DISCUSSION...Gorelow AVIATION...Stessman For more forecast information...see us on our webpage: or follow us on Facebook and Twitter