Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/29/21

Area Forecast Discussion
National Weather Service Des Moines IA
846 PM CST Tue Dec 28 2021 .UPDATE... Issued at 825 PM CST Tue Dec 28 2021 Made some adjustments this evening to the snow forecast for Wednesday as a low-amplitude mid level wave quickly slides through the region.Model cross sections show weak static stability and a zone of EPV reduction through the DGZ, co- located with the zone of stronger frontogenetical lift stretched sw to ne across the southern half of the state. This is a favorable setup for an focused area of enhanced, deep lift to develop and produce locally higher precipitation amounts. Snow ratios also may contribute to boosted snowfall amounts with a cooler, more dendritic profile and relatively relaxed winds supporting above climo SLR. Cobb output suggests mean SLR of 16-19:1. Antecedent dry air may play a significant limiting role as is shown in recent HRRR runs, however confidence is growing that a band of locally higher snowfall amounts may be realized tomorrow afternoon and evening. Overall, snow totals were not substantially increased, but were pushed toward the 1-3" range over a targeted area to highlight the potential for locally higher snowfall amounts, especially given the sensitive timing of any potential impacts from heavier snowfall/rates around the afternoon commute. && .DISCUSSION.../Tonight through Tuesday/ Issued at 122 PM CST Tue Dec 28 2021 Key Messages: -Active and variable winter weather continues this week -Light snow Wednesday -Stronger system with cold temps and snow expected Saturday Rest of today: Ongoing mixed precip event currently playing out as exected and will continue lifting north and east this evening as the short wave exits and cold front approaches from the west. Tonight: Cold air will push in behind the cold front, stting the stage for single digit lows tonight along Iowa`s northern border. Wednesday: Southwest flow aloft continues and another short wave will cross the state during the afternoon. Given the cold air in place, this short wave is expected to generate a round of light snow across much of the state. Moisture is limited and the short wave will be moving quickly, so snow amounts are expected to be minor with amounts under 2 inches. Thursday: Temperatures should moderate a bit Thursday as southerly low level flow returns in between systems. The next cold front (a strong one this time) is progged to cross the area Thursday night. Friday and Saturday: The cold air will push in Friday, setting the stage for single digit lows Friday night and highs Saturday from the single digits north to upper teens south. Then Saturday a well advertised wave is progged to lift out of the southwest US and take aim on the midwest. Models continue to differ considerably on the evolution of the upper trough and subsequent track of the surface low. Latest ECMWF runs continue to track the wave across Iowa which would yield higher snowfall amounts for our area. Meanwhile the GFS continues to track farther south, suggesting lower snowfall amounts and impacts for our area. Of the two models, the ECMWF has been a bit more consistent so would lean slihtly toward that solution at this point. Regardless of the eventual track, given the cold temperatures, any snow that does occur is likely to be very fluffy and with wind gusts in the 15-25 mph range should blow around. Sunday through Tuesday: After the long wave trough passes by Saturday night, northwest flow will set up aloft and quieter weather will kick off next week. After another colder day Sunday, temperatures return to near normal for the start of the next work week. && .AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/ Issued at 531 PM CST Tue Dec 28 2021 Low cigs/visby problems will persist into the evening hours for the sites east of I-35, including KMCW, KALO, and KOTM. All sites should improve to VFR by 09z and remain there for much of Wednesday. Snow chances increase after 18z, but intensity and location remains uncertain at this time. Included mention of -SN and MVFR restrictions at KDSM after 20z to highlight the area of highest confidence at this time, although this will need to be refined in future TAF issuances. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Martin DISCUSSION...DMD AVIATION...Martin
Area Forecast Discussion
National Weather Service Goodland KS
413 PM MST Tue Dec 28 2021 .SHORT TERM...(This evening through Thursday) Issued at 134 PM MST Tue Dec 28 2021 At the start of the short term period, current RAP analysis shows the CWA having a west-southwesterly flow aloft being underneath the base of an upper air trough on Tuesday afternoon hours. Model guidance shows this trough tilting positively going into the Tuesday night hours turning the flow over the CWA southwesterly. At the surface, the cold front has passed through the CWA by the early afternoon and is leaving some breezy mostly northerly winds looks to be to have passed through the CWA with gusts up to around 35 mph in some portions of the CWA for the rest of the afternoon. Winds look to lighten by the evening hours going through the night. Cold lows on Tuesday night between the upper single digits to the lower teens are expected. Wind chills overnight look to drop between -3 and +3 degrees across the CWA particularly after midnight. On Wednesday, models show the southwesterly flow over the continues in the morning and transitions back to west-southwesterly by the evening hours as the base of the trough moves over the CWA again. Closer to the surface, cooler daytime high temperatures ranging between the upper 20s and the middle 30s are expected in the CWA as the latest NAM shows an 850mb cold air mass moving over the area during the afternoon hours along with some cloud cover in the morning that may inhibit early diurnal warming. While the NAM shows a small chance for light precipitation in the northeastern quadrant around 15Z, opted to keep low PoPs as other models do not show this. Surface winds look to be around 5 to 10 mph that look mostly northeasterly to northerly during the day that turn southerly overnight. Overnight lows on Wednesday expect to range between the upper single digits and the middle teens with wind chills ranging to just below zero degrees to the upper single digits. The flow over the CWA looks to stay mostly west-southwesterly again throughout Thursday while models show a trough building out west and reaching down to the southwestern CONUS. At the surface, there looks to be a warmer air mass moving in from the southwest during the day with a surface low near the CO/NE/KS border. Windy conditions return to CWA particularly in the western half as southwesterly wind gusts up to 35 mph are seen at this time. There may be some elevated to near critical fire weather concerns in this area as well with minimum RH values in the upper teens. Daytime high temperatures on Thursday look to be in the lower to middle 50s with overnight lows in the middle teens to middle 20s. .LONG TERM...(Friday through Tuesday) Issued at 113 PM MST Tue Dec 28 2021 A shot of cold arctic air set to impact the entire region Friday on into Saturday. A strong cold front will push quickly south thru the CWA during the day on Friday. Latest GFS/ECMWF do show this being followed by a 500mb trough mainly Friday night into Saturday. This trough will traverse the area by late Saturday, with mid level ridging to follow to end off the holiday weekend. Weather concerns with the passage of this system will range from light snow area-wide, gusty winds bringing the potential for some areas of blowing snow. And lastly, very cold wind chill readings as temps drop sharply during the overnight periods. First off at the onset, the quick moving cold front may trigger some light precip in extreme south possibly starting as very light rain but transition quickly as temps drop. The dry airmass this system will work into going into Friday night and Saturday morning will keep amounts low, with latest forecast trending around an inch. Gusty winds could create areas of blowing snow and thus hazardous travel conditions in spots. Will have to monitor for potential Winter Weather Advisory issuance for potential travel impacts. The latest 850mb temps show a range from -11c to -18c during the overnight period Friday, with slightly warmer numbers Saturday night in a -9c to -14c range. For winds, strongest set to occur Friday into Saturday with gusts 25 to 30 mph possible. Sunday will have the potential for gusts nearing 25 mph on the return WSW flow as high pressure shifts east of the area and a lee side trough setting up over the eastern slopes/Front Range. For the beginning of next week, a return to dry and more normal conditions across the area. For temps, highs on Friday will range widely due to the cold front pushing south. Looking for a range from the 30s north of the Interstate, to the 40s and lower 50s south. Currently this looks to occur around the midday timeframe, but some uncertainty in frontal passage timing in latest GFS/ECMWF. Highs on Saturday only in the lower to mid 20s at best. An upward trend ensues on Sunday with a return to a west-southwest downslope flow. Looking for a range in the 40s, warmest west. For overnight lows, Friday night will have a range from -1F to +6F. Saturday night, just as cold with a range from -2F to +5F. By Sunday night though, low to mid teens. With the expected winds, wind chill readings will range from about - 14F to -19F Friday night, -9F to -18F for Saturday night and single numbers above and below zero for Sunday night. If the trend holds for the Fri/Sat timeframe, a Wind Chill Advisory may be needed. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 410 PM MST Tue Dec 28 2021 VFR expected at both KGLD and KMCK through the TAF period. Surface winds will be light behind a cold front, veering from northeast to southeast at less than 10 kts. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...76 LONG TERM...JN AVIATION...024
National Weather Service Morristown TN
1004 PM EST Tue Dec 28 2021 .UPDATE... EVENING UPDATE. && .DISCUSSION... The forecast is generally on track this evening, so no major changes are needed. Highest PoPs over the next few hours will be in the Plateau in a low level convergence zone. Later tonight, the HRR shows showers increasing as the LLJ strengthens and the convergence zone moves into the TN Valley. The forecast PoPs of likely to caregorical look warranted. Some obs have stayed very warm due to gusty winds, and will make some adjustments to hourly temps. DGS && .AVIATION... 00Z TAF DISCUSSION. The general trend to cigs through the night will be toward lowering, particularly at CHA and TYS where MVFR conditions are expected as rain showers develop in the area after 06Z. Downslope winds should keep cigs VFR at TRI overnight and tomorrow morning. Waves of showers will continue at times through tomorrow, with the best chances in the afternoon. Any vis reductions should be assoicated with showers, and mainly MVFR. TS may be possible at CHA in the afternoon as well. Winds through the period will be S-SW around 8-12 kt. DGS && .PREV DISCUSSION... /ISSUED 324 PM EST Tue Dec 28 2021/ SHORT TERM...(Tonight and Wednesday)... Key Messages: 1) Conditional risk of strong to severe thunderstorms on Wednesday afternoon; mainly across the southern Cumberland Plateau and southern valley. 2) High moisture content will favor heavy rain rates and localized flooding with thunderstorms. Discussion: We remain warm and anomalously moist on Wednesday as deep SW flow continues across the region between longwave troughing across the Great Plains and ridging off the Florida coast. Isentropic ascent within this SW flow will continue to bring cloud cover and scattered showers to the region. A strong shortwave will move northeast through the upper flow across the mid- Mississippi Valley and into the Great Lakes late on Wednesday into Wednesday night. Some weak DPVA will be present across the Tennessee Valley and Southern Appalachians, but the strongest dynamics will remain to our west. A weak surface low is forecast to develop across the Mississippi Valley and move ENE into KY and the Ohio Valley on Wednesday night. A lingering boundary across the region, in addition to the weak DPVA and thermodynamics, will result in the potential for some severe weather on Wednesday evening into Wednesday night across the Tennessee Valley. The overall severe risk is conditional and will be dependent on the amount of surface based instability. If height falls associated with the shortwave are strong enough, and increase in instability will be possible into the overnight hours. There is still a lot of uncertainty on exactly where this better instability and mid-level lapse rates set up, though, so the overall risk is conditional. If enough instability is present, and the RAP currently shows 500 to 800 J/Kg into Wednesday night, shear is supportive for cellular storm modes such as multicell clusters and supercells with a low potential for tornadoes and strong winds; however, the more favorable setup continues to be to our west where better low-level veering is present in closer proximity to the developing surface low. Based on the current SPC outlook and severe weather probabilities, will at least mention a risk of some severe thunderstorms in the forecast for the southern valley and southern Cumberland Plateau. Thunderstorms that do develop will likely produce heavy rain rates which may lead to some localized flooding issues. PW values are around 1.4 inch across southern zones which is around the 99th percentile to max of climatology. In addition, deep warm cloud layer depths will result in warm rain processes. This combination will favor heavy rain rates. The one mitigating factor will be recent dry weather, but heavy rain rates could still result in localized issues and prime the antecedent environment for more flooding concerns over the remainder of the week. JB LONG TERM...(Wednesday night through Tuesday)... Key Messages: 1. Unseasonably warm through Saturday. 2. Strong to severe storms possible late Wednesday and Wednesday night. Heavy rainfall possible Wednesday night into Thursday morning. 3. Another strong system will impact the area bringing heavy rainfall and the potential for strong storms Saturday and Saturday night. 4. Colder weather Sunday through Tuesday. Discussion: By Wednesday night, the weak shortwave will have lifted into the Great Lakes. Curvature is weak with this shortwave with only weak height falls spreading across the Tennessee and Ohio Valley. A baroclinic zone will be entrenched from the central Appalachians southwest across the Midsouth and into the southern plains. The weak wave lifting across the Mississippi Valley will spark cyclogenesis, albeit weak, along the boundary. This surface low will lift NE along the front into the Ohio Valley by Thursday. The fetch of southerly flow for several days now has been able to advect Gulf moisture poleward into the Southeast and Tennessee Valley. Additional influx of higher theta-e air will accompany a strengthening LLJ in response to the wave to our northwest. Dewpoints will increase into the low to mid 60`s by Wednesday night. This airmass characterized by low- mid 60 dewpoints will yield weak MLCAPE values across at least portions of the southern valley. Ongoing convection at the start of the period due to primarily isentropic ascent along the 290-300K surfaces will move NE across much of the Tennessee Valley. Assuming some of this activity could become surface based would present chances of strong to possibly severe storms. The severe threat for Wednesday night is conditional on instability. Recent point soundings from CAM guidance depicts some low-level CAPE along with modest shear profiles. If we were to see some breaks in the cloud cover then this could certainly modify the boundary layer so that higher CAPEs could be realized. As the low level jet continues to intensity, vertical wind shear will increase. A potential wild card will be if a secondary surface low can potentially develop as has been noted in several past runs from the GFS. This would cause local backing of the wind profile and subsequently lead to an increase in SRH. Another thing to watch for is that recent guidance and forecast soundings show additional warming near 700mb leading to a slight cap that may keep convective coverage limited. This is especially true with the weak forcing expected. Locally damaging winds will be the main threat with any strong to severe storms although a secondary threat of an isolated tornado or two is certainly possible with sufficient low-level CAPE (3CAPE > 60J). Confidence is still rather low at this point on convective mode and coverage, but the risk is there for strong to severe storms. The other hazard is locally heavy rainfall potential Wednesday night and Thursday morning. Anomalous moisture will be present as PW values surge to between 1.25-1.50 inches (200-300% above climo). Additionally, these numbers are near the 99th percentile based on 1979-2009 CFSR climo. The anomalous moisture will likely interact with a boundary that is progged to sag south into portions of the area. NAM, GFS, and to a lesser extend the ECMWF depict an increase in 850-700mb frontogenesis developing Wednesday night. This forcing along with anomalous moisture will lead to periods of heavy rainfall. Luckily, it has been relatively dry so that we should be able to handle a couple inches of rainfall without major issues. However, any training convection could cause localized flooding issues. On Thursday, the area remains well into the warm sector airmass. Southwest flow aloft will continue to transport moisture into the area. Forcing will be hard to come by on Thursday, but will leave in PoPs for the higher terrain through Thursday night where upslope could keep showers going across these areas. The warm weather pattern continues for Friday and Saturday. On Friday, a warm front lifts back north while aloft, a deep upper level northern stream trough digs across the Rockies and phases with a southern stream disturbance near the four-corners. Robust cyclogenesis develops within increasing height fall across the plains. A couple of surface lows will ride along the baroclinic zone Friday and again on Saturday night. Numerous showers and thunderstorms will move through the area beginning Friday and will continue through Saturday. Moisture continues to be anomalous with this system. NAEFS tables suggest Q and PW values will be well near the 99th percentile or higher of climo. Additionally, PW values from ensembles are near 200- 300 percent of normal. Such anomalous moisture content along with deep moisture profiles, high WBZ heights, and elevated CAPE supports efficient warm rain processes. An additional couple inches of rain is supported by deterministic and ensembles guidance. This additional rainfall on top of recent rains from the midweek system could cause flooding issues. Finally, conditions will need to be monitored closely on Saturday evening for possible rounds of strong to severe thunderstorms. Jet dynamics increase ahead of the incoming trough axis with a 140-160 knot upper level jet. A LLJ develops in response across much of the warm sector airmass. This will promote an increase in boundary layer moisture/instability. There are a lot of unknowns in how much instability can be achieved especially with possible convective overturning issues given heavy rainfall. However, much stronger winds fields means that vertical wind shear will be stronger with this system. High pressure descending from the plains will push the cold front through the area on Sunday with impressive cold air advection behind the front. Temperatures will return to near normal behind this front. Depending on how much moisture is left behind the front, some change over to light snow may be possible on the back side of this system but it is still way to early to pinpoint any accumulations. Diegan && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 64 74 62 72 56 / 90 90 90 60 20 Knoxville McGhee Tyson Airport, TN 63 73 59 69 54 / 70 90 90 70 20 Oak Ridge, TN 63 71 59 69 53 / 80 90 90 50 20 Tri Cities Airport, TN 59 70 55 66 50 / 50 80 90 70 20 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$
Area Forecast Discussion
National Weather Service Nashville TN
847 PM CST Tue Dec 28 2021 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... A line of showers and even a couple rumbles of thunder are focused along our eastern extent of the CWA. Rain has been moderate to heavy with 0.5"-1" falling in the last hour in southern Coffee and western Grundy counties according to MRMS. 00z KOHX sounding showed about 100-200 J/kg of MLCAPE which explains the lightning being observed. RAP mesoanalysis currently shows higher instability along and west of I-65 with a tongue of 500 J/kg of MLCAPE. The front that keeps sagging and lifting the last couple of days is currently along the Ohio River Valley and will sag back down into the area after midnight bringing additional showers and storms. Models keep 250-500 J/kg MLCAPE just south of the front after midnight and into the early morning hours. Factoring in this with ample shear, it is possible that we may see a strong storm capable of gusty winds. As far as the current forecast is concerned, the hourly PoPs had some minor adjustments, otherwise no major changes were made. && .AVIATION... 00Z TAF DISCUSSION. CKV/BNA/MQY/CSV...Several admendments possible thru 29/24Z per expected fluctuations in ceiling heights, errosion/then reestablishment of ceilings, fluctuations in vsbys, etc. 40kts LLWS possible MQY 29/03Z-29/06Z per strengthening low level atmospheric jet dynamics. Variable ceilings & vsbys expected thru 29/24Z. Mostly VFR/MFR with IFR at times. Light shwrs should prevail or vcnty potential thru 29/24Z. Instability expected to be strong enough to support tstm development around/after 29/12Z. Strongest convection expected generally S of terminals. Swly sfc winds 5-15kts with gusts to around 20kts at times, especially before 29/06Z when strength of sfc/low level pressure gradient most enhanced. Due to sfc front proximity and possible push SEWD into NW portions of mid state 26/09Z-26/24Z, sfc winds could potentially veer SE CKV 26/09Z-26/24Z also. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......Reagan AVIATION........JB Wright
Area Forecast Discussion
National Weather Service Phoenix AZ
500 PM MST Tue Dec 28 2021 .UPDATE... Updated Aviation discussion. && .SYNOPSIS... Several fast moving weather systems will pass through the region this week providing periodic chances for precipitation. The best chances should occur through this evening and late Thursday through Friday with lower desert rain showers and higher terrain snowfall. The greatest weather impacts should occur late in the week. The weather pattern may shift next week allowing the cooler, unsettled conditions to be replaced by drier weather and moderating temperatures. && .DISCUSSION... Scattered light showers continue this afternoon across south- central Arizona ahead of an approaching shortwave trough currently situated near southern California. Amounts from these showers have been light (around a few hundredths of an inch) with Phoenix Sky Harbor picking up 0.01" of rain so far. Temperatures today will top out in the mid to upper 50s across central Arizona, while areas across southeast California and southwest Arizona that have seen clearing this afternoon finish in the low 60s. The aforementioned shortwave trough will progress through the state during the evening and promote additional shower development mainly across central portions of the state. Amounts are expected to remain light with most places across the Valley staying below 0.25". Areas that see more orographic enhancement will see better totals with some of these areas potentially seeing amounts upwards of 0.50-0.75". Snow levels will be around 4,500-5,000 feet with wintry precipitation expected across the higher peaks east of Phoenix into southern Gila County, such as the Pinal/Superstition/Mazatzal Mountains, where a Winter Weather Advisory is in effect for elevations above 4,500 feet through 5 AM MST Wednesday morning. Several inches of snow will be possible for these higher peaks, though a capping inversion above 700 mb will inhibit dendritic growth and thus act to limit the snowfall threat. The trough axis shifts east of the state going through the overnight hours with showers tapering off across our forecast area. HRRR suggest skies clearing out enough overnight for some possible patchy fog development for areas that see rain. However, additional modeled guidance keeps the region locked in under thicker cloud cover and preclude any potential fog. With the passage of the shortwave, the Desert Southwest will remain under the influence of broad cyclonic flow through the next day or so. Modeled soundings keep a saturated layer between 700-850 mb during this time allowing for expansive cloud cover to persist through much of this timeframe. With the lack of evident forcing mechanisms, shower potential is expected to remain limited across much of the CWA. NBM PoPs keep slight chances for rain Wednesday before increasing Thursday ahead of our next weather system. .PREVIOUS DISCUSSION... Confidence is now very good that a compact, yet deep negative PV anomaly will intensify west of the Baja Thursday night, then eject and become sheared and absorbed into the strengthen jet core along the international border Friday. This system will partially tap better quality subtropical moisture with a more meridional sfc-H8 component allowing better poleward advection. However, the intensity and rapid forward motion of an upstream wave blasting south will cut the residency time of this PV anomaly and ability to fully realize the potential IVT plume. In fact, the rapid shearing of the wave will quickly yield veering winds and significant restriction to the inland penetration of the moist tongue. Nevertheless, boundary layer mixing ratios ~7 g/kg and total column PWATs above 0.75" juxtaposed with favorable dynamics should result in an excellent precipitation chance across much of the forecast area. NBM POPs ranging from 50% west to 90% east seem reasonable for this situation. With the deep cold core northerly wave descending and amplifying over the four corners, will need to watch for the potential of moderate snow burst through Gila County Friday night. Residence time of this wave and moisture corridor combined with the colder airmass should be somewhat brief, and thus possibly restricting snow totals though the stronger dynamics could overcome this temporal deficiency. Regardless, this system will rapidly propagate into the southern plains Saturday afternoon with a deep, cold continental airmass bleeding south in its wake. Forecast thicknesses and H8 temperatures suggest freezing temperatures over non-urbanized, sheltered lower elevations Sunday morning (i.e. colder than normal, but nothing unusual for this time of year). The initial stage of this pattern retrogression will be complete during the first part of next week with a flat ridging/zonal flow becoming the more dominant regime over the SW Conus. Typically this time of year, this pattern will produce periodic thicker high clouds, but temperatures moderating very close to the seasonal normal. && .AVIATION...Updated 0000Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Anticipate scattered to numerous light showers primarily between 00-06Z with large fluctuations in ceilings as each shower passes overhead. Within that period of time, anticipate ceilings and visibilities to be lowest between 02Z-04Z with conditions at or near MVFR thresholds. Prior to that, anticipate a lot of variability in ceilings ranging from 4-7kft AGL with visibilities AOA 6SM. After 06Z, shower probabilities decline quite a bit but anticipate lingering ceilings of 3-4Kft AGL. Ceilings will continue to linger through the day Wednesday though there may be a period in the morning where ceilings temporarily scatter out. Surface winds will favor westerly directions this evening before trending to southeasterly overnight and favoring the southeast quadrant during the day Wednesday. Southeast California/Southwest Arizona including KIPL and KBLH: Scattered clouds (occasionally broken) with bases 6-8Kft AGL will continue through the evening and slowly decrease after sunset. Southwest/Westerly windiness with gusts of 25-30kts will decrease considerably this evening with lighter southwesterly winds lingering overnight and through the morning. Above the surface, moderate to strong westerly winds will continue but conditions are expected to remain below LLWS conditions. Anticipate some redevelopment of breezy conditions Wednesday afternoon but not quite as strong as this afternoon. && .FIRE WEATHER... Thursday through Monday: Temperatures will continue below normal through this week, then begin to moderate next week. A moist environment combined with several weather disturbance will result in periodic chances for precipitation with some snowfall accumulation over higher terrain in eastern districts Friday. Minimum afternoon humidity levels will struggle to reach 40% with some drying arriving over the weekend. Overnight recovery should be excellent in a 60-100% range. Wind speeds appear fairly typical for the season with potentially some enhancement of northerly winds behind a front over the weekend. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Winter Weather Advisory until 5 AM MST Wednesday for AZZ557-558- 563. CA...None. && $$ DISCUSSION...Smith PREVIOUS DISCUSSION...18 AVIATION...AJ FIRE WEATHER...18