Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/08/22

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
842 PM MST Wed Dec 7 2022 ...New UPDATE... .UPDATE... Issued at 835 PM MST Wed Dec 7 2022 HRRR continues to suggest while the upper level moisture is shunted eastward over NM, south winds will continue to feed low level moisture into the Pecos Valley and over portions of southeast and east central NM through much of the night, resulting in areas of locally dense fog. Consequently have issued a Dense Fog Advisory ending at 5am. This may or may not need to be extended depending how quickly drier air starts to move in. Also added patchy blowing snow to the northern mountains for tonight. && .UPDATE... Issued at 552 PM MST Wed Dec 7 2022 Sending out an update for isolated thunder over portions of central NM. Also adding patchy fog to portions of the Pecos Valley into east central/southeast NM with guidance indicating low level moisture will linger. && .SYNOPSIS... Issued at 159 PM MST Wed Dec 7 2022 A storm over The Great Basin interacting with Pacific moisture will bring low elevation rain showers and high elevation snow Wednesday night through Thursday morning, particularly across northwest New Mexico. Temperatures will cool over the northern portion of the state and remain below average through Saturday, while the rest of the state remains near to a few degrees above average. A strong Pacific storm will begin to impact the state on Monday, beginning the potential for strong winds along the southern mountains. Precipitation enters the state from the west, but it may not make it all the way to the eastern border because the storm is expected to exit into the Northern Plains. Cooler temperatures associated with the storm means snow accumulations are possible down to valley floors. Potentially significant snow accumulations and blowing snow are possible in the mountains. && .SHORT TERM... (This evening through Thursday night) Issued at 159 PM MST Wed Dec 7 2022 The haze in the air over portions of NM is sulfur dioxide (SO2) aerosols from Mauna Loa, HI getting caught up in the westerlies. Radar reflectivity is starting to increase over the northwest third of NM early this afternoon as a filling closed low is on approach from southeast NV. Sufficient low level moisture in streaming in from the southwest will combine with the atmospheric lift from the trough to result in a round of showers with snow showers above about 8,000 feet this evening, falling to near 6,000 feet by early morning Thursday. Higher snow accumulation will favor the Tusas mountains including Chama and the northern Sangre de Cristo mountains. Decided to include forecast zone 213 (northern Sangre de Cristo mountains) in the Winter Weather Advisory given slightly higher precipitation amounts from this morning`s model runs and the fact that the Rio Hondo Valley between Arroyo Seco and TSV is favored in a moist southwest flow scenario such as this. Brisk northwest winds develop most areas Thursday behind the associated surface cold front and with cooler air moving in, it will feel much colder than today`s readings. && .LONG TERM... (Friday through Tuesday) Issued at 159 PM MST Wed Dec 7 2022 A weak upper level wave will race east thru late Friday with another batch of high clouds and breezy SW winds. Max temps will remain up to 5F above normal, especially over eastern NM. A weak backdoor cold front will slip into northeast NM with no more than a wind shift. Saturday will be nice again with slightly above normal max temps, lighter winds, and mostly sunny skies. Sunday will still be relatively nice however changes do begin with a deepening surface low along the Front Range and widespread breezy winds. Temps warm up to 10F above normal across the east with the stronger winds. Ridge top winds strengthen Sunday night as a potent upper level jet arrives from the west. A few high terrain areas may be hitting close to Wind Advisory after midnight. A powerful cold front is expected to enter western NM Monday morning in association with the next winter storm. Confidence is increasing at this time for minor to moderate impacts across much of northern and western NM due to significantly colder temps, strong winds, light to moderate snow, and blowing snow Monday and Monday night. The main issue with forecast confidence is timing as supported by variance in the 12Z WPC Cluster Analysis. Deep moisture may also struggle to push much farther east than the Divide as much drier, westerly flow arrives with strong cold advection Monday night. NBM 75th percentile snow accums over 48-hours supports advisory level accums across the north and west however impacts with cold and wind may support warning level impacts in a few zones. The 12Z GEFS probability of 30+ mph sustained winds focused the greater chances across the southern high terrain with potential for 40+ mph sustained winds over the Sacramento Mts. Cold temps remain in place in the wake of this system for several days with potential for snow showers to continue along west and northwest-facing slopes thru Wednesday. && .AVIATION... (00Z TAFS) Issued at 430 PM MST Wed Dec 7 2022 Upper low/trough moving through the Great Basin/Four Corners with moist sw-wly flow over NM. Mts occasionally obscd especially over wrn and central NM north of I-40 in sct MVFR to IFR cigs/vsbys in rain and snow showers as well as isold thunder and br. Conditions improving aft 08/12Z with lcl nwly winds gusting to around 35kt along portions of the central mt chain. && .FIRE WEATHER... Issued at 159 PM MST Wed Dec 7 2022 Scattered rain with snow showers above about 8,000 feet will move into northern NM late this afternoon into tonight. Several inches of accumulation are possible mainly in the Carson NF near the CO border. Brisk northwest winds will bring localized elevated critical conditions to the eastern and northeastern plains Thursday afternoon but wind speeds are forecast to remain below critical thresholds. Tranquil days remain on track for Friday through the weekend with winds increasing early next week ahead of a powerful winter storm system forecast to bring widespread snow to much of the Southwest U.S. Monday night and Tuesday. && .PRELIMINARY POINT TEMPS/POPS... Farmington...................... 27 44 21 48 / 40 0 0 0 Dulce........................... 19 42 7 45 / 80 5 0 0 Cuba............................ 25 41 18 47 / 50 0 0 0 Gallup.......................... 20 44 16 50 / 10 0 0 0 El Morro........................ 21 42 20 46 / 10 0 0 0 Grants.......................... 20 45 15 51 / 10 0 0 0 Quemado......................... 23 46 24 51 / 5 0 0 0 Magdalena....................... 29 49 27 52 / 10 0 0 0 Datil........................... 24 46 24 50 / 10 0 0 0 Reserve......................... 23 54 22 55 / 10 0 0 0 Glenwood........................ 32 55 32 57 / 20 0 0 0 Chama........................... 17 36 8 39 / 90 10 0 0 Los Alamos...................... 27 41 24 45 / 90 0 0 0 Pecos........................... 27 45 25 46 / 50 0 0 0 Cerro/Questa.................... 24 38 17 41 / 70 0 0 0 Red River....................... 19 35 11 40 / 70 5 0 0 Angel Fire...................... 21 36 -4 41 / 60 5 0 0 Taos............................ 24 41 9 44 / 70 0 0 0 Mora............................ 25 45 19 50 / 50 0 0 0 Espanola........................ 28 48 21 52 / 80 0 0 0 Santa Fe........................ 29 43 25 46 / 60 0 0 0 Santa Fe Airport................ 26 45 20 48 / 60 0 0 0 Albuquerque Foothills........... 34 48 29 49 / 40 0 0 0 Albuquerque Heights............. 35 49 28 51 / 30 0 0 0 Albuquerque Valley.............. 33 51 25 53 / 30 0 0 0 Albuquerque West Mesa........... 32 50 27 51 / 30 0 0 0 Belen........................... 29 52 20 53 / 20 0 0 0 Bernalillo...................... 32 52 26 52 / 40 0 0 0 Bosque Farms.................... 29 51 20 53 / 30 0 0 0 Corrales........................ 32 51 27 52 / 40 0 0 0 Los Lunas....................... 30 51 22 53 / 30 0 0 0 Placitas........................ 32 46 27 49 / 40 0 0 0 Rio Rancho...................... 32 50 27 50 / 40 0 0 0 Socorro......................... 32 55 28 55 / 10 0 0 0 Sandia Park/Cedar Crest......... 28 42 27 45 / 40 0 0 0 Tijeras......................... 30 44 24 47 / 40 0 0 0 Edgewood........................ 27 45 21 48 / 40 0 0 0 Moriarty/Estancia............... 24 46 16 51 / 40 0 0 0 Clines Corners.................. 27 43 23 47 / 30 0 0 0 Mountainair..................... 28 46 24 49 / 30 0 0 0 Gran Quivira.................... 31 47 27 50 / 20 0 0 0 Carrizozo....................... 37 53 32 55 / 10 0 0 0 Ruidoso......................... 34 49 30 54 / 10 0 0 0 Capulin......................... 28 49 20 50 / 20 0 0 0 Raton........................... 24 53 15 53 / 20 0 0 0 Springer........................ 24 54 16 57 / 20 0 0 0 Las Vegas....................... 29 52 22 52 / 30 0 0 0 Clayton......................... 34 57 25 55 / 10 0 0 0 Roy............................. 30 54 21 53 / 20 0 0 0 Conchas......................... 37 60 25 59 / 10 0 0 5 Santa Rosa...................... 36 55 29 58 / 10 0 0 5 Tucumcari....................... 39 59 26 59 / 20 0 0 5 Clovis.......................... 40 58 31 58 / 30 0 0 10 Portales........................ 41 61 30 59 / 30 0 0 10 Fort Sumner..................... 37 58 30 57 / 20 0 0 5 Roswell......................... 40 63 34 60 / 20 0 0 0 Picacho......................... 36 61 30 62 / 20 0 0 0 Elk............................. 34 59 30 61 / 20 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 AM MST Thursday for NMZ210-213. Dense Fog Advisory until 5 AM MST Thursday for NMZ235-236-238. && $$
Area Forecast Discussion
National Weather Service Amarillo TX
537 PM CST Wed Dec 7 2022 ...New AVIATION... .SHORT TERM ... (This evening through Thursday night) Issued at 137 PM CST Wed Dec 7 2022 Rain is still looking to be on the way this afternoon and evening. Elevated fire weather may affect the northwest tomorrow. West Texas Mesonet is picking up some light precip in the south- central TX Panhandle this afternoon. The HRRR model has been doing the best so far today with handling the light precip on radar to the south and projecting the light precip making it to the Panhandles by the noon timeframe. Other short range models have been missing precip, so will follow the HRRR for most of the rain forecast noting that the other models are similar within a couple hours. Rain will continue pushing north from the south plains through the afternoon. A shortwave from northern Mexico will cross southeastern NM and reach the Panhandles this afternoon. If the HRRR projection is correct, the Amarillo area will be likely to see rain around 4-5 PM until around 9 PM when it pushes eastward. The whole band of precip could be out of the area as soon as 2 AM, but there are several ensemble members maintaining precip through 12Z to warrant some pops until the morning. All the models hold the instability to the south, so have removed lightning from the forecast. As the moisture moves off to the east, clouds will clear out of the western Panhandles for the night. As the upper level low crosses the Rockies, the lee side low in northern NM/southern CO will shift eastward during the day Thursday. A LLJ will strengthen through the morning and mixing will bring down some of those stronger winds to the surface. By the afternoon through, the jet weakens as the upper level low crosses into Nebraska thus decreasing the surface winds. The breezy winds and drying from the downsloping flow during the afternoon may bring some elevated fire weather conditions to the northwestern Panhandles. With clear skies and light winds overnight, temps will cool Thursday night into the 20s and low 30s. Beat && .LONG TERM ... (Friday through next Tuesday) Issued at 137 PM CST Wed Dec 7 2022 Weak high pressure will remain over the Gulf of Mexico and gradually become suppressed through the weekend. Overall southwest flow will hold on Friday with temperatures right around normal. A weak disturbance will pass north of the Panhandles and there`s a chance for late afternoon to early evening moisture, mainly over the southeast Panhandle, but it may still track over a bit of the central Panhandles. Fast moving cold front behind the disturbance will bring temperatures down a few degrees on Saturday. A large scale trough will moved down the west coast and begin to transition the flow over the central high plains to be more out of the southwest. As a result Sunday`s highs should be in the low 60s for the most part with dry and breezy conditions possible over the Panhandles. This same pattern is expected on Monday with even drier air over the Panhandles, however the winds may be a bit lighter as the surface low moves closer. Overall, southwest winds in the 15-25 mph range are expected. Pacific front expected to move through Monday evening into Tuesday. This will keep winds on the breezy side out of the west on Tuesday, but temperatures will be a bit cooler. The cold front Tuesday evening with a north wind shift out of the north. Overnight lows Tuesday night look to be down in the teens to 20s, and with the wind out of the north the wind chills in the single digits to low teens. Weber && .AVIATION... (00Z TAFS) Issued at 530 PM CST Wed Dec 7 2022 Some light rain showers continue for the southeastern TX Panhandle going into the 00Z period. KDHT is expected to stay VFR through the 00Z TAF period. If conditions do drop off for KDHT they should not last long. Most of the low level moisture will stay east of KDHT and primarily impact KGUY and KAMA with LIFR to IFR CIGs and possibly some reduced VIS as well through much of the first quarter to first half of the TAF period. Winds are expected to remain light, less than 10 kts through about 15Z. After 15Z, KAMA may see winds pick up to around 15 kts. Conditions should start to improve for KAMA and KGUY by 08Z as drier air moves into the combined Panhandles. 36 && .FIRE WEATHER... A weather system will be approaching the Southern High Plains this towards the tail end of the weekend, and into early next week. As this system nears we could be looking a few days of breezy to windy conditions. Right now Sunday and Monday look to be prefrontal winds, whereas Tuesday looks to be more cooler and post frontal. Overall, the RH values could range in the low teens to mid 20 percent range, and with winds in the 25-35 mph range the RFTI`s could range from 3 to 5, with some very isolated 6`s if the worst conditions line up. Elevated, to possibly critical Fire Weather is expected on these days. Weber && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 59 45 62 30 / 30 40 0 0 Beaver OK 47 40 64 25 / 10 20 0 0 Boise City OK 64 37 59 24 / 0 10 0 0 Borger TX 56 47 65 31 / 20 20 0 0 Boys Ranch TX 64 42 63 26 / 20 20 0 0 Canyon TX 56 45 63 30 / 50 40 0 0 Clarendon TX 51 47 64 35 / 60 60 0 0 Dalhart TX 66 37 60 23 / 10 10 0 0 Guymon OK 52 42 63 25 / 10 10 0 0 Hereford TX 59 43 62 30 / 50 30 0 0 Lipscomb TX 49 43 66 29 / 30 30 0 0 Pampa TX 56 46 63 32 / 30 40 0 0 Shamrock TX 50 46 66 34 / 70 70 0 0 Wellington TX 50 45 66 35 / 70 70 0 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...16 LONG TERM....89 AVIATION...36
Area Forecast Discussion
National Weather Service La Crosse WI
530 PM CST Wed Dec 7 2022 .DISCUSSION...(Tonight through Wednesday) Issued at 218 PM CST Wed Dec 7 2022 Key Messages: - Weather system will bring a band of snow and a mixed bag of wintry precipitation to mainly areas southwest of I-94 starting late Thursday into Friday. This will have impacts on travel. - Could see some light wintry precipitation, mainly snow, on Saturday. - A large weather system will take shape in the Midwest next week which could bring more rain and snow but details will be worked out as it draws closer. TONIGHT: Lingering clouds and precipitation Patchy fog and low ceilings have been slow to depart to the southeast this afternoon with a quasi-stationary cold front bifurcating the forecast area from northeast to southwest. The driving upper level perturbation has provided light, minimally impactful snow in our central Wisconsin counties. Have draped precipitation potential slightly further south with this passing low level forcing band. THURSDAY / FRIDAY: Mixed precipitation threat and travel impacts The upper level disturbance responsible for Thursday`s weather maker can be seen over the Desert Southwest this afternoon on satellite water vapor imagery. Rocky Mountain lee cyclogenesis tonight into tomorrow morning ejects through the Central Plains into the Upper Midwest along the subtropical jet and best quasi-geostropic forcing. Initial impacts will be fog in similar spots as this morning as the surface high exits over the Great Lakes and low level winds turn southerly and higher dewpoints enter our southern reaches. High resolution ensemble forecasts have delayed precipitation onset Thursday with entrained mid to low level dry air. RAP (01.15Z) soundings have this entrained dry air with deep layer saturation not occurring until late Thursday night in our southwestern counties. This dry entrained air will assist in limiting initial freezing precipitation as the elevated warm nose eeks north into the forecast area through Thursday. A more zonal and later into afternoon/evening track of the surface low is resulting in less warm air penetrating north into the forecast area. Short term ensemble and higher resolution soundings have trended colder compared to previous forecasts, resulting in less widespread freezing rain and rain. High resolution ensemble forecasts continue higher confidence for freezing rain to our south and west. Long range ensemble forecasts (GEFS/EPS 07.12Z) contain highest confidence for 3 inches of accumulated snowfall from northeast Iowa into southwest Wisconsin. The recent GEFS continues the warmer bias than the EPS, with increased lower level thicknesses further north into the forecast area. With this more northern warm nose, the higher confidence for 3" snowfall totals pushes slightly further north in the Wisconsin River Valley. The best low level frontogenesis in the deformation band reaches the forecast area late Thursday night into Friday morning as the low progresses the Plains. Expect increased precipitation rates during this time. Overall impacts remain similar to previous forecasts, with initial onset pushed further into the evening providing more snow likelihood than previous forecasts. Still, amounts are similar, 2-4" bifurcating the forecast area from northeast Iowa into central Wisconsin. Friday morning commute appears to be most applicable travel impacts with this updated timing. After coordination, have issued an advisory for combination of snow and mixed precipitation threat. Adjustments might be needed as forecast trends change. As the surface low exits to the east on Friday afternoon, a mid level dry punch results in loss of upper level ice nucleation. Precipitation type during this time could be of the freezing variety with surface temperatures flirting with the 0C isotherm. Have not introduced increased mixed precipitation at this time given lack of high resolution guidance, but something to keep an eye on as the forecast hour nears. HRRR (07.18Z) contains this lack of ice and <0C thermal profile astutely. SATURDAY: Light snow threat In wake of late week system, much stronger signal now for another short wave trough passage on Saturday. Previous model runs showed light precipitation from warm air advection, but now with stronger dynamics showing up in the deterministic runs, could see several hours with light accumulations perhaps. Quick glance at top down profiles suggests mainly snow but with relatively mild airmass still in place, could be a mix of rain and snow in southern tiers. Bottom line is precipitation chances continue to increase overall. TUESDAY / WEDNESDAY: Large Midwest storm will bring more precipitation to area Attention still turns to large central U.S. system next week. Flow becomes highly amplified with more signals that large upper trough will occlude and become closed system hence slowing overall progression. While ensemble clusters continue to show good agreement in this pattern shift, still some differences on timing. Main detail for us will be precipitation types assuming we stay in the warmer sector. High anomolies of moisture pushing northward will likely make for a higher QPF system so as event draws closer, will have to watch thermo profiles to see if we remain more liquid. Could also see some convection. ECMWF ensembles appear to be warmer and even suggest we could get into a dry slot scenario with loss of ice. Will likely keep pushing up temperatures, especially by Tuesday. In any event, lots of details to work out including extent of impacts for our area. If warm front holds south of the area, could be more mixed precipitation issues, but at some point occluded front will wrap around and we will get into colder air. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 530 PM CST Wed Dec 7 2022 Main taf concerns are MVFR to IFR conditions due to fog development late tonight into Thursday at the both taf sites. Weak surface high pressure builds into the Upper Great Lakes Region tonight into Thursday. Southerly flow on the backside of surface ridge increases low level moisture across the region late tonight. With clear skies and light winds...fog or low level stratus is expected to develop across portions of northeast Iowa/southwest Wisconsin after 06z Thursday and potentially spread northward during the morning hours. Issue will be how far north the fog/stratus moves. At this time...have introduced MVFR visibility reduction at both taf sites after 08z Thursday and continue to around 16z Thursday. Due to time of the year...there is the possibility the fog/stratus may not erode til early afternoon or around 18z Thursday. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...Winter Weather Advisory from 6 PM Thursday to noon CST Friday for WIZ053>055-061. MN...Winter Weather Advisory from 6 PM Thursday to noon CST Friday for MNZ079-086>088-094>096. IA...Winter Weather Advisory from 6 PM Thursday to noon CST Friday for IAZ008>011-018-019-029-030. && $$ DISCUSSION...JAR/Shea AVIATION...DTJ
Area Forecast Discussion
National Weather Service Denver/Boulder CO
839 PM MST Wed Dec 7 2022 .UPDATE... Issued at 830 PM MST Wed Dec 7 2022 Water vapor shows a strong trough over western Utah that is moving toward northwest Colorado. There is moderate QG ascent ahead of this trough and some instability in western Colorado leading to some lightning and thunderstorms. Currently, there is dry air over our CWA leading to a lack of precipitation. After midnight, the precipitation should fill in over the mountains especially the Park Range and the far northern Front Range. Some minor adjustments were made to the PoPs to lower them before midnight and to winds to increase them tomorrow but the overall forecast remains on track. The biggest thing to watch will be whether a mountain wave develops in eastern Boulder County and produces strong winds. The HRRR has gusts up to 65 knots which is higher than expected but not out of the question. && .SHORT TERM...(This evening through Thursday) Issued at 215 PM MST Wed Dec 7 2022 This evening and tonight, the trough will continue to advance, weakening, and flow will be more blocked orographically as it turns more to the south. However, there will be increasing synoptic ascent ahead of the trough which will keep light to moderate snowfall going in the high country. QG fields suggest the best forcing will be this evening, overnight and early morning. Lapse rates steepen to 7 to 8 C/km over most of the area. Expect generally 1 to 3 inches across the mountains, perhaps up to around 5 inches in favored areas of the Front Range, and 3 to 9 inches for most of the Park Range including around Rabbit Ears Pass. There is just a slight chance for the plains late tonight through early in the morning. Precipitation will be limited by a lack of moisture, but high resolution models do show some banded showers. The best chance will be over the far northeast plains in the morning with increasing low level moisture. We have issued a Winter Weather Advisory for the Park and Gore Ranges (more for the Park than Gore) from 5 PM this afternoon to 5 PM tomorrow, for travel impacts due to snow and blowing snow. The greatest impacts will occur late night and early morning. Tomorrow, there will be decreasing snowfall with subsidence, clearing and drying behind the trough axis. It also looks to get pretty breezy by late morning or early afternoon, due to increasing westerly flow aloft and subsidence, and an increasing pressure gradient. Some cross-sections show a weak mountain wave amplification. Expect breezy winds across the mountains and higher foothills, especially over exposed east slopes, gusting up to around 55 mph. Breezy winds should spread over the plains by around noon, but will likely not be nearly as widespread as models are currently indicating. There will be areas of northwesterly winds gusting up to around 45 mph. Humidity should be high in most areas, but elevated fire weather conditions are possible for a few hours in the afternoon on the plains around the Palmer Divide (especially east and southeast) where minimum humidity may fall to near the critical 15 percent threshold. Any critical conditions that do develop should be limited in coverage and duration so we do not plan for any fire highlights at this time. .LONG TERM...(Thursday night through Wednesday) Issued at 215 PM MST Wed Dec 7 2022 There is brief upper ridging over the forecast area Thursday night. A weak open wave upper trough is progged to push across Colorado Friday afternoon and evening. There is more upper ridging for Saturday, then southwesterly flow is progged to increase in speed Saturday night. There is downward synoptic scale energy on the QG Omega fields Thursday night, then weak ascent Friday and Friday evening. This is followed by more subsidence into Saturday afternoon. Benign energy is in place Saturday night. Models show little moisture for the forecast area Thursday night well into Friday. There is bit of low level moisture progged on the cross sections over the mountains Friday afternoon and evening. It is pretty dry again through Saturday night, with just some upper level moisture Saturday afternoon. The QPF fields have no measurable precipitation for the CWA Thursday night into Friday, then none on Saturday and Saturday night. There is a bit of snow indicated for the mountains Friday afternoon and night. Will go with "scattered" pops in the mountains Friday afternoon and evening. For temperatures, readings look to stay right at or a bit above seasonal normals Thursday night through Saturday night. Looking at Sunday through Wednesday, there is still pretty strong southwesterly flow aloft for Sunday. That decreases Monday then an upper trough/closed low moves across Colorado Monday evening through Tuesday. Latest model runs now show the low level cold front to move into the CWA Monday night. Cold north and northwesterly flow aloft will be in place Wednesday. The medium range models are in better agreement today. At this time the trough/closed low does not look like a major snowfall producer, but there are a few days to go. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 438 PM MST Wed Dec 7 2022 VFR conditions through the TAF period. There is a DCVZ sitting just off the west side of the airport currently. The mostly likely scenario is that it stays in place for the next few hours allowing winds to slow back towards the northeast. However, if the boundary does move eastward, northwest winds will be possible for a couple of hours. If the boundary does move over the airport, it would trigger low level wind shear sensor alerts. Later this evening, winds will trend towards drainage. A difficult part of the forecast will be correctly predicting the strength of the winds tomorrow afternoon. While gusts up to 35 knots are possible in the afternoon, the majority of the time will have lighter winds with gusts less than 30 mph. The stronger winds will be on and off throughout the afternoon. The winds will weaken in the late afternoon and back towards drainage. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 5 PM MST Thursday for COZ031. && $$ UPDATE...Danielson SHORT TERM...EJD LONG TERM...RJK AVIATION...Danielson
Area Forecast Discussion
National Weather Service Duluth MN
555 PM CST Wed Dec 7 2022 .DISCUSSION...(This evening through Tuesday) Issued at 352 PM CST Wed Dec 7 2022 Summary: Expect quiet and cold conditions tonight as high pressure builds. Temps will warm tomorrow, with highs reaching the 20s for most locations. There will be a couple chances for accumulating snow throughout the forecast period. One of those chances will be on Saturday, where a quick 1-2" may be possible. The second chance will be mid next week, where a potentially impactful amount of snow may be possible. However, there is still uncertainty associated with next week`s system, so it`s too soon for specifics on snow amounts. Conditions have become quiet this afternoon as a clipper system advects downstream and sfc high pressure develops. Current obs show that lake-effect snow has developed along the South Shore. Model soundings from the RAP indicate that this snow will likely continue for the next few hours along the South Shore, as delta-T between 850mb and the lake sfc remains around 19 degC. As low-level saturation decreases late this afternoon and easing winds veer easterly, this snow will come to an end. Additional accumulations resulting from lake-effect snow today are expected to be less than an inch in Iron County and within the higher elevations of the Bayfield Peninsula. Expect cold temps tonight as lows drop below zero for a large portion of the CWA. Wind chills will be reaching as low as -25 degrees, mainly in Koochiching and northern St. Louis Counties. Despite the potential for -25 degree wind chills tonight, decided against issuing a Wind Chill Advisory given the short residence time of wind chills below -25 and possible cloud development. Temps will be increasing on Thursday as a WAA regime sets up over the CWA, warming highs into the 20s for most locations. A low pressure system will be moving from the Southwestern U.S. into the mid-Mississippi River valley on Thursday into Friday. Impacts will likely be minimal, as the low pressure tracks through Iowa and much of the CWA will be under a split flow pattern aloft. Light snow will be possible for the southernmost areas of our CWA on Thursday night into Friday morning. Accumulations are expected to only be a tenth or two of an inch for the southernmost portions of the CWA. Looking ahead to this weekend into next week, there are two timeframes of interest. The first will be late Friday night through Saturday as a negatively-tilted trough propagates through the area. Model soundings indicate that freezing drizzle may be possible late Friday night into early Saturday morning, as the low-levels saturate from the sfc to around 800mb at a temp of around -5 degC. Since the profile above 800mb will be moderately dry, this may lead to freezing drizzle development and light ice accumulations in north-central MN. As additional moisture advects into the CWA and the saturated layer deepens on early Saturday morning, expect any freezing drizzle that develops to transition to snow. Light snow is likely to continue through the day Saturday before coming to an end in the evening as the through slides east. Probability of exceedence maps for Saturday`s system place the highest confidence in accumulations around 1-2" across the CWA. The second timeframe of interest will start on Tuesday and continue through mid next week. Ensemble and deterministic models continue to develop a large Colorado Low on Tuesday as a longwave trough propagates through the Intermountain West. While it`s still too soon to dive into specifics regarding snow accumulations, early indications show that this may be an impactful system bringing appreciable amounts of snow. Make sure to keep an eye on the forecast as we head into next week for additional details as confidence increases. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 555 PM CST Wed Dec 7 2022 VFR conditions are expected this TAF period. A ridge of high pressure slides across the area overnight, and even as it slides off to the east on Thursday, the area remains in between systems and little if any cloud cover is expected. There are some small concerns for fog and/or stratus developing over the area overnight, but probabilities have decreased and have left out of the 00z TAF set. LLWS is possible overnight in the 08z-12z time range for KINL with strong winds aloft associated with a system well to our north. && .MARINE... Issued at 352 PM CST Wed Dec 7 2022 High pressure is expected to dominate the pattern from this afternoon through most of Thursday, creating relatively quiet conditions. Variable winds this evening into tonight will shift to the southwest on Thursday morning. Winds will likely be highest along the North Shore from Taconite Harbor to Grand Portage tomorrow with gusts approaching 20 knots. Waves will also be highest within this area of the North Shore tomorrow, with heights of 2-4 feet. The next chance for Small Craft Advisory conditions likely won`t be until Friday into the weekend as east-southeast winds increase. && .PRELIMINARY POINT TEMPS/POPS... DLH -1 24 16 32 / 0 0 10 10 INL -12 21 6 30 / 0 0 0 0 BRD 0 24 16 32 / 0 10 20 0 HYR 0 28 16 34 / 0 0 20 10 ASX 3 29 16 35 / 10 0 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && $$ DISCUSSION...Unruh AVIATION...LE MARINE...Unruh
Area Forecast Discussion
National Weather Service Louisville KY
1047 PM EST Wed Dec 7 2022 .Forecast Update... Issued at 1040 PM EST Wed Dec 7 2022 The cold front that passed through earlier today is now south of the forecast area, with a strong sfc high pressure located near the Great Lakes. This sfc high is streaming cool north-northeasterly flow into the region. The cold front to our south is expected to lift back north as a warm front tomorrow, bringing additional rounds of showers to the area. No major changes are needed to the forecast, though did expand patchy fog wording for the overnight. Moisture trapping underneath a low level inversion will keep dewpoint depressions near or less than 3F overnight. Did look for any drizzle potential, but a notable dry layer just above the inversion keeps the warm cloud layer rather shallow, and saturation is not deep enough to support any. However, should be a foggy/dreary night, with some CAMs such as the HRRR suggesting some advection type fog. Light NNE winds should remain elevated enough to inhibit widespread dense fog, but certainly could have some locally dense fog in some areas. Otherwise, temps will remain in the 40s and low 50s tonight. Updated products have been sent. && .Short Term...(This evening through Thursday) Issued at 300 PM EST Wed Dec 7 2022 The cold front is finally pushing out of the SE CWA at this hour, with light rain down near the Lake Cumberland region ending. With strong surface high pressure (1035+ mb) moving across eastern Canada and the Great Lakes region tonight, enough influence from that feature extends into our area to keep us dry. However, the break in precipitation will be short-lived as an overrunning rain shield will already be setting up and beginning to overspread the area by around or just before sunrise tomorrow. The surface cold front that is currently sinking southward out of the CWA will begin lifting back north over the TN Valley through Thursday as a warm front, likely arriving near or just south of the KY/TN border by 00z Friday. Meanwhile, a modest 25-30 knot low level jet is expected to overrun the surface boundary on Thursday, providing isentropic lift and deeper moisture transport beneath some forced ascent from a mid to upper impulse. Deep moisture looks pretty good for the southern half of KY where peak precipitable water values should range in the 1.3 to 1.5 inch range. These values would be between 90-100% peak PWAT values for this time of year. As a result, widespread rain is expected which warrants the categorical (90-95% pops) for south central KY. Also have categorical mention for southern IN and northern KY, but slightly less in the 80-90% range given slightly lower PWATs. Overall, expecting between a .3 and .75" of rain through Thursday, with the higher amounts across our south and more rain to fall overnight. A few localized areas could go up over an inch, but that isn`t expected to be widespread. Given the 12 to 18 hours of recovery time from previous rain, and 1 hr FFG values likely ranging between 1 and 2" in most spots we should be able to mostly handle the rainfall. Can`t rule out a few nuisance flood events, especially across the southern CWA but don`t expect any major problems at this time. Any available instability looks very meager to non-existent, but suppose a few rumbles of thunder could accompany the strongest cells on Thursday. Not likely though. Given the frontal boundary just south of our CWA, expect a notable temp gradient to continue N to S. Look for low 40s tonight across southern IN steadily warming to the low 50s across southern KY. Thursday high temperatures will range from the upper 40s/low 50s north to upper 50s low 60s south as the warm front approaches. .Long Term...(Thursday night through Wednesday) Issued at 320 PM EST Wed Dec 7 2022 Showers and a few elevated thunderstorms could be on going at the start of the forecast period Thursday evening into Friday morning. Surface boundary will be draped across southern KY/northern TN along with a 35-40kt LLJ riding along the boundary adding to the shower and possible storms with the bulk of the activity across southern KY into TN. There will be a good N-S temperature gradient when it comes to our lows overnight with low/mid 40s along the Ohio River and southern IN to low/mid 50s from the parkways southward into TN. Post frontal air will work in behind the departing system during the day Friday. Some lingering showers are still possible through the morning as PoPs decrease from west to east during the morning hours. Highs will once again follow that same pronounced N-S temperatures gradient with low/mid 50s across southern IN/northern KY and upper 50s to low 60s across southern KY. While drier air filters in aloft, low level moisture may keep some stubborn stratus around for Friday especially across northern KY and southern IN. Rain chances have increased for the start of the weekend as the combination of an embedded shortwave trough passing by to our north and a weak sfc low coming out of the plains moves through the Ohio Valley Saturday afternoon and evening. By Monday, mid-to-upper level ridging and sfc high pressure should bring the best chance for dry weather region-wide over the next 5-7 days. Temperatures will begin to warm again with increasing thicknesses pushing highs into the mid-to-upper 50s. This system looks to move by fairly quick producing QPF values ranging from a tenth of an inch or less for most of central KY with the exception of locations along and south of the Western KY and Bluegrass Parkways where a tenth to a quarter of an inch of rain could fall. High will be in the low/mid 50s with upper 40s into southern IN. Sunday through Monday looks to be our driest stretch of weather over the long term as ridging aloft begins to build in over the Ohio Valley. This ridging is in response to a deepening trough across the western US becoming a closed off low over the Intermountain West by Monday. Temperatures Sunday and Monday will be close to seasonal norms with lows in the 30s and 40s and highs in the low 50s. Deterministic models continue to show good agreement on an amplifying weather pattern into the first half of next week. Aforementioned closed upper low over the Intermountain West will work eastward and be over the Northern Plains by Wednesday. Lee cyclogenesis off the Rockies will result in a surface low developing over Colorado`s Front Range and working northeast over the Northern Plains as the system looks to be become vertically stacked. At this time, we anticipate showers and storms to arrive from the west on Tuesday into Wednesday ahead of an approaching cold front. The better overall dynamics seem to be shifting further west and south in the most recent runs of the deterministic models but the pattern should still be watched for the possibility of strong and potentially severe storms. Model soundings over the area show little to no CAPE but good amount of shear. We will continue to keep our eye on this system and evaluate model runs and trends as we get closer to next week. && .Aviation...(00Z TAF Issuance) Issued at 635 PM EST Wed Dec 7 2022 Flight cats have been teetering between MVFR and IFR this evening as ceilings remain around 1000ft across most of the region. As we progress through the night however, expect to see conditions further deteriorate to solid IFR ceilings at the terminals. Light winds will veer from a northerly flow this evening to a northeasterly flow by tomorrow. Guidance suggests some instances of LIFR in some locations for tomorrow, but only had enough confidence to include a TEMPO group at LEX for LIFR ceilings before sunrise. Otherwise, we will see light rain showers move into the region tomorrow morning as a warm front meanders just to the south, which should produce widespread light rain, low ceilings, and restricted vis through the rest of this TAF period. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...CJP Short Term...Brian Long Term...Brian Aviation...CJP
Area Forecast Discussion
National Weather Service Raleigh NC
900 PM EST Wed Dec 7 2022 .SYNOPSIS... A front will remain quasi-stationary over the west-central Carolinas through tonight. A separate, backdoor cold front will settle south across NC early Thursday, with following high pressure that will extend across the mid Atlantic through Saturday. && .NEAR TERM /THROUGH TONIGHT/... As of 900 PM Wednesday... Recent radar trends show light rain activity decreasing in coverage and intensity. Meanwhile, stable and nearly saturated low level conditions remain with vsbys across much of central NC, particularly north of the Hwy 24 corridor, 5 miles or less in fog. While hi-res models show that we should remain mostly precip-free after the current light rain ends after midnight, there is ongoing concern regarding fog potential overnight. One notable trend in the HRRR and other hi-res guidance this evening is a low level and sfc wind shift to NW overnight. This wind direction is not favorable for fog, and with dwpts lower to our north, dwpt progs overnight also show a decreasing trend. In addition, forecast soundings also show that low level saturation that extends up to about 1km agl per the 00Z observed GSO sounding may begin drying from the top down overnight, again, thanks to the developing NW flow. The exception may be across our far western tier of counties from Davidson south to Anson, where the CAD and low level saturation may persist the longest. For now, will follow vsby trends and address areas of dense fog with SPS as needed, unless the dense fog becomes more widespread before the NW flow kicks in, then at which time we`ll need to consider a dense fog advisory. Low temperatures in the 50s still appear to be on-track. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... As of 320 PM Wednesday... A mid/upper-level low over the Intermountain West this afternoon will track enewd and reach the mid/upr MS Valley by 12Z Fri. Preceding the low, an accompanying low/mid-level WAA regime and frontal zone will retreat north across the mid MS and lwr OH Valleys and srn mid Atlantic. The ern extension of that frontal zone will be elevated atop surface high pressure that will have ridged south across the mid Atlantic, in the wake of the backdoor cold front that will move south across cntl NC early Thu. A period of brightening skies/partial sunshine will be possible during the midday-early afternoon hours behind a band of thick stratocumulus that will settle south into srn NC by 18Z, but the day will otherwise average cloudy or mostly so owing to the presence of morning overcast and fog, the stratocumulus, and a stream of continued mid/high-level moisture. The daylight hours should be mainly dry, however, until the aforementioned WAA regime and Fgen result in the ewd development/ expansion of a shield of mainly light rain into the nw NC Piedmont around sunset and ewd across the remainder of cntl NC through Thu night. While most locations will experience rain Thu night, amounts are expected to be light and range from just a hundredth or three across the Sandhills and srn Coastal Plain to a tenth to quarter inch over the nrn Piedmont. Despite the clouds and nely flow behind the front, it will be unseasonably mild once again with high temperatures in the 60s, followed by lows in the 40s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 300 PM Wednesday... Rain will continue across the region Friday as an upper trough traverses east across the Mid-Atlantic and a cold front and surface low approach from the TN Valley. Cool air will remain in place as a surface high across southern Quebec maintains and strengthens CAD across central NC. This high has trended stronger over the last few days, which has lowered highs Friday down to the mid-40s N to upper 50s S. Rain will diminish from west to east by late Friday evening. Ridging aloft and at the surface then build across the region on Saturday keeping the weather dry, however CAD conditions will keep low clouds around for another day. Highs on Saturday will be similar to Friday, with lows Saturday and Sunday mornings returning to the upper 30s to 40s. A weak cold front and shortwave then quickly sweep across the region from the northwest on Sunday. Precipitable water values increase to near one inch, however conditions across central NC look fairly stable and only light to moderate rain is expected at this time. Rain should exit east Sunday afternoon, with Sunday night becoming dry. Stronger ridging builds in aloft early next week as surface high pressure builds across the Mid-Atlantic. CAD looks to weaken to where we`ll finally see the sun on Monday, and dry and more clear conditions may continue into Tuesday. Highs will linger near seasonal normals early next week. A deep low will then move across the Midwest around Wednesday, with a deep trough digging across the Carolinas the middle of next week. This looks to be our next best chance of rain, however models and their ensembles keep delaying the arrival of the system. If this trend continues, the ridge may loiter longer and create dry conditions into Wednesday. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 700 PM Wednesday... 24-hour TAF period: Widespread ceilings in scattered visibilities in the IFR to MVFR range are currently observed across central NC outside of the far SE (including FAY). While the low-level flow will begin to shift northwesterly overnight, the environment will still remain fairly moist and winds will be light, setting up potential for areas of fog with IFR to LIFR visibilities, particularly across the western Piedmont (including INT and GSO). Visibilities will quickly improve to VFR by mid-morning, and ceilings should rise to MVFR by this time. These MVFR ceilings should linger through much of the afternoon in most of central NC outside of the far NE (including RWI) behind a backdoor cold front (and associated thick band of stratocumulus) that will move through in the morning. Light rain may start to move back into the far NW (including INT and GSO) by late Thursday afternoon. Winds will remain light, shifting from their current SW direction to NW then N overnight, before shifting NE tomorrow. Looking beyond 00Z Friday: The passage of a disturbance aloft will encourage the development and ewd expansion of a shield of mainly light rain and IFR-MVFR conditions across cntl NC Thu night-Fri. Additional disturbances aloft will overspread and interact with high pressure that will extend across the mid Atlantic and result in periods of rain and sub-VFR conditions in cold air damming through Sunday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR SHORT TERM...MWS LONG TERM...JJT AVIATION...Danco/MWS
Area Forecast Discussion
National Weather Service San Angelo TX
540 PM CST Wed Dec 7 2022 ...New AVIATION... .SHORT TERM... (This afternoon through Thursday) Issued at 155 PM CST Wed Dec 7 2022 Unsettled weather conditions will continue through the remainder of the day and into the evening. Current satellite imagery overlaid with 500mb RAP analysis shows a thick stream of clouds moving up out Mexico and across the Southern Plains. However, areas south of the I-20 corridor are beginning to see some breaks in the clouds with a decent CU field developing along and south of Hwy87. Surface analysis shows a stationary frontal boundary hanging out in and around the I-10 corridor. South/southeasterly flow will continue pull in moisture across the southern half of Big Country with DP temps in the mid 60s and air temps in the 70s. In fact, the decent moisture streaming in from the south in combination with the healthy fetch streaming in from the southwest in the mid to upper levels, PW values range between 1.1-1.4 inches. Global ensemble guidance even suggests PW values being 250-300 percent of normal, indicating a rather moist air mass in place. As the boundary gradually lifts to the north through the afternoon/evening hours, closer to the Red River Valley vicinity, thats where the greatest chances of showers/storms lie. Areas to the north of I-20 will see scattered showers/storms through the evening and into the overnight hours. Rainfall rates should remain relatively light with isolated instances of moderate rates under the heaviest thundershowers. Further south, closer to the I-10 corridor, rain chances decrease through the day and into the overnight hours. However, with meager instability in place over southern parts of Big Country, an isolated storm or two will be possible through the evening. Temperatures this afternoon will top out in the upper 60s to middle 70s across the forecast area. By tomorrow, an upper level trough will swing across the Central Rockies, slowly pushing the anomalous moisture further to the east. Isolated showers and storms remain in the WX grids through the morning hours for areas to the north and east. That being said, slightly drier air and continued warmth can be expected for tomorrow across most of the forecast area. && .LONG TERM... (Thursday night through next Tuesday) Issued at 1155 AM CST Wed Dec 7 2022 The long term forecast picks up on Thursday night with drier air infiltrating the forecast area from the north and west. The stint of drier air will not last long. By Friday, another upper level shortwave trough will race across the Central Rockies. Most of the western half of TX will be under the influence of southwest flow aloft. However, lingering low level moisture will be in place as the area remains under the influence of southerly flow at the surface. High temperatures on Friday will hover around the 70 degree mark across the forecast area, upper 60s to the north and lower 70s to the south. A Pacific cold front associated with the upper level trough will dive in from the northwest late Friday night and into Saturday morning. Isolated showers and storms will be possible during that timeframe as the front traverses the region. Weather conditions dry out by Saturday afternoon with a fairly quiet and pleasant start to the weekend expected. Temperatures on Saturday will remain above the seasonal average, right around the 70 degree mark. In response to the departing trough axis, slight ridging but predominately zonal flow will set up across the region on Sunday. This upper level flow regime will result in another quiet and pleasant day to end the weekend. High temperatures on Sunday will once again hover around the 70 degree mark with mostly clear skies, more clouds possible to the south and east. By Sunday night and into Monday, upper level flow will continue to turn to the southwest as another larger and stronger trough begins it`s trek across the Intermountain West. Southwest flow will further increase on Monday, resulting in slightly warmer temperatures, low 70s area wide. This upper level trough is progged to dig across the Desert SW before swinging across the Rockies. As a response to the upper level low strengthening over the Rockies, deep cyclogenesis will develop over the Front Range Mon/Tues timeframe. Breezy to windy conditions can be expected Monday night into Tuesday. && .AVIATION... (00Z TAFS) Issued at 540 PM CST Wed Dec 7 2022 Currently most sites are at VFR or high end MVFR ceiling heights. This will change within the next 3 to 6 hours at most sites. As temperatures cool, and moisture is lifted by a nearly stationary front in the area, CIGs will deteriorate into the MVFR range by around 06Z, then CIGs could continue to fall into the IFR or even LIFR range at KSOA during the morning hours Thursday. Have also added some BR at KSOA for a few hours Thursday morning. Expect conditions to slowly improve across most of the region during the afternoon hours Thursday, but KBBD, KJCT, and KSOA may remain in the MVFR range through Thursday evening. Winds will be generally out of the south tonight, turning the southwest during the day Thursday. && .PRELIMINARY POINT TEMPS/POPS... Abilene 58 73 50 69 / 40 10 0 10 San Angelo 62 75 54 73 / 10 10 0 10 Junction 61 75 58 74 / 10 10 10 0 Brownwood 61 75 56 73 / 10 20 10 10 Sweetwater 58 73 50 67 / 50 0 0 10 Ozona 61 72 56 71 / 10 10 0 10 Brady 62 73 58 72 / 10 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...99 LONG TERM....99 AVIATION...20