Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/24/22

Area Forecast Discussion
National Weather Service Birmingham AL
801 PM CST Wed Nov 23 2022 ...New SHORT TERM... .SHORT TERM... (Tonight through Thursday) Issued at 748 PM CST WED NOV 23 2022 Temperatures are not falling as quickly this evening as previous two nights as winds have become southeast several thousand feet above the surface. The most interesting feature this evening is a large area of low clouds moving westward across south Georgia. The RAP model is the only model that seems to have a handle on the moisture advection. The clouds will likely reach those Alabama/Georgia state line around midnight, mainly impacting areas along and south of I-85. The RAP has the clouds advancing into most of east Alabama by sunrise Thursday. The moist layer is too shallow for any raindrops, so no rain expected. Given the warm temperatures experienced today, raised highs tomorrow a few degrees most areas. Rain with the next system still not expected into west Alabama until Thursday evening. 58/rose Previous short-term discussion: (This afternoon through Thursday) Issued at 1133 AM CST WED NOV 23 2022 Surface high pressure over the east coast will continue to weaken and move east today. Flow will become somewhat northerly this afternoon with drier air advecting in and skies clearing becoming partly cloudy for much of the day. Overnight...flow will shift to out of the south and southwest...bringing more moisture and warm air advection ahead of an approaching frontal boundary. PW values will slowly increase from the 0.50 average to around 1.00 inches through the day on Thursday with cloud cover increasing tonight through Thursday. With mostly cloudy skies Thursday... temperatures will be near the same as they will be today. Rain is expected ahead of this front late Thursday with light showers possible in the late afternoon and early evening. The models have trended slightly slower with timing for the have left a slight chance for the far west in the forecast before 7 pm. Most of the rain should move through beginning in the evening through the rest of the night. High temperatures today will be in the mid 60s to lower 70s. Low temperatures tonight will be in the 40s. High temperatures tomorrow will be in the upper 60s and lower 70s. 24 && .LONG TERM... (Thursday night through next Tuesday) Issued at 215 PM CST WED NOV 23 2022 Widespread rainfall, north of a warm front to our south, will end through the day on Friday. A surface low along the front struggles to push northward, and expect thunder to remain elevated Thursday night and Friday. A break in widespread rainfall is expected Friday night and into Saturday, before the upper low rotating over western Texas moves eastward toward the Mississippi River Valley. Most of the rainfall will hold off until Saturday afternoon. Cannot rule out thunder, but instabilities are weak. Did increase gradient winds Saturday and Sunday, with some gusts up to 20-25mph possible. Adjustments were made to account for timing changes with the arrival and departure of rainfall, and increase in wind speeds. Otherwise, extended forecast is on track. 14 && .AVIATION... (00Z TAFS) Issued at 513 PM CST WED NOV 23 2022 Minimal cloud cover thru 06z due to a dry air mass is place across Alabama. A low level easterly flow over Georgia will advect higher moisture into east Alabama overnight. Cigs arnd 2000 ft agl over east Georgia will move into far east Alabama arnd 06z and to near the I-65 corridor by 12z. The MVFR cigs will slowly lift after 15z and become VFR by 18z. Light rain will enter far west Alabama by the end of the period with rain overspreading central Alabama Thursday night. 58/rose && .FIRE WEATHER... South to southeasterly winds will set up tonight increasing cloud cover and moisture slowly through the day tomorrow. Rain chances return Thursday late afternoon and evening. through Friday morning. A break in the rain is expected Friday evening and into Saturday morning, before another system moves through the area, with rain chances through Saturday night. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 40 68 47 64 / 0 10 90 60 Anniston 45 68 51 65 / 0 10 90 70 Birmingham 47 69 53 65 / 0 10 90 60 Tuscaloosa 47 70 54 66 / 0 10 100 50 Calera 47 69 54 65 / 0 10 90 60 Auburn 50 66 54 65 / 0 10 80 70 Montgomery 48 71 56 68 / 0 10 80 60 Troy 49 71 56 70 / 0 10 70 60 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...58/rose LONG TERM....14 AVIATION...58
Area Forecast Discussion
National Weather Service Pueblo CO
601 PM MST Wed Nov 23 2022 .UPDATE... Issued at 600 PM MST Wed Nov 23 2022 Expired the Red Flag Warning. Humidity should increase above critical thresholds quickly this evening, although gusty winds will likely persist in some areas for a few more hours at least. && .SHORT TERM...(This evening through Thursday) Issued at 238 PM MST Wed Nov 23 2022 Key Messages: 1) Snow is expected to over and near the higher terrain tonight and continue through Thanksgiving Day. For the high country and the Palmer Divide, light to moderate snow accumulations are expected. 2) Highest snow accumulations and dangerous travel conditions are expected in our southern Sangres and the Raton Mesa, where a Winter Weather Advisory has been issued. Currently.. Water vapor imagery shows the base of a deep trough pushing into western Colorado this afternoon, where a low is expected to close off over the next several hours. Extremely dry air is being pumped into region ahead of this system, with strong westerly drainage winds pushing through all of our usual gap flow prone areas as well. This set up is leading to critical fire weather conditions for the middle Arkansas River Valley and the southern I-25 corridor, where relative humidity values have plummeted into the single digits. A weak preceding surface trough has pushed through, bringing a northerly wind shift to northern El Paso county. The Air Force Academy is currently seeing 21 mph northerly winds which has brought their dew point up several degrees this hour. MRMS shows light snowfall starting to push into Lake County. Tonight.. The HRRR brings our main cold frontal boundary into northern portions of Teller and El Paso county around 7pm this evening. Northerly winds are expected to gust up to 30 mph behind this boundary, persisting through the overnight hours. Snow continues to push into the Continental Divide region overnight tonight, with steady snow beginning around midnight for our Southern Sangres. A Winter Weather Advisory has been issued for this region, along with the Raton Mesa, from midnight tonight until tomorrow evening, with snow accumulations of 5 to 10 inches expected across the southern Sangres and into Raton Pass and 2 to 6 inches expected across the southern I-25 Corridor. Snow fall across the Pikes Peak region and the Palmer Dvd could range from 1 to 4 inches, greatest across northeastern Teller County and northwestern El Paso County. We are not expecting much, if any, accumulations in Colorado Springs or further south across southern El Paso County into Pueblo County or the rest of the southeast plains. The rest of the higher terrain and southern and western portions of the San Luis Valley could see a few inches of snow as well. Tomorrow.. Snow continues for most of the high country throughout the day tomorrow, clearing from northwest to southeast through tomorrow afternoon. For the Palmer Divide, expect wind driven snow to begin any time after midnight, increasing in intensity during the early morning hours. This will make for hazardous driving conditions on I- 25 for our Thanksgiving Day travel plans. Though snow amounts are not expected to be high, visibilities will be low at times, with the northerly winds gusting up to 40 mph through the day. Wind chills will likely be in the single digits for most of El Paso county from about 2am until 11am tomorrow morning. Daytime highs are expected to get up into the low to mid 40s tomorrow for the lower Arkansas River Valley, with 30s elsewhere on the plains. Mountains and mountain valleys are expected to stay in the 20s and 30s as well. For our southern Sangres and the Raton Mesa, to include the southern I-25 corridor, snowfall is expected to increase in intensity as upslope deepens, mainly from about 3am until noon tomorrow. Northerly wind gusts of 40 to 50 mph are also expected for this time period, which will likely lead to dangerous travel conditions, especially through Raton Pass. Snow begins to taper off through tomorrow afternoon, with drier air moving in after sunset tomorrow evening. A few areas of highest uncertainty with this forecast period will be for the Wet Mountains and southern and western portions of the San Luis Valley. Both of these areas could potentially see higher than currently forecast snow amounts, mainly due to potential snow bands setting up in the deformation zone later tonight and into Thursday morning. A slight shift towards a more easterly wind direction later tomorrow morning could also lead to enhanced upslope snowfall for the Wets. jme/mw .LONG TERM...(Thursday night through Wednesday) Issued at 238 PM MST Wed Nov 23 2022 Key messages: 1) Some lingering snow showers will occur over the southern Sangre de Cristo Mountains, Raton Mesa area, and southeastern plains Thursday evening through Friday morning. A few snow showers will be possible late afternoon/evening on Friday over southeastern Baca County. 2) Much warmer initially on Saturday, then a cold front will move through late morning/afternoon over the plains, with a few snow showers possible over the central mountains Saturday evening through early Sunday morning. 3) After a cooldown on Sunday, there will be a slight warmup Monday ahead of the next low pressure system that will bring much colder temperatures and snow possibly for all of southeast Colorado next Tuesday through Wednesday. Detailed discussion: Thursday night through Friday... As the major shortwave tough with an associated U/L closed low at the 500 mb level continues to move south over New Mexico, so will the precip. Upsloping will help to keep some snow over the Raton Mesa area, as well as the southern Sangre de Cristo Mountains into the early morning hours on Friday. There will also be some snow, and a rain/snow mix continuing over the southeastern plains from the deformation zone. The NNW`ly winds will advect in some much cooler temperatures in so lows will be about 10 degrees colder under clearing skies with a brisk wind, and produce wind chill values in the single digits over parts of the eastern plains, as well as eastern El Paso County. Lows will drop into the teens over most of the plains, and into the single digits for a good part of high country. Some lower level clouds and patchy freezing fog may develop in the San Luis Valley into early Friday morning, especially in close proximity of the Rio Grande riverbed. On Friday, high pressure will continue to build back in behind the exiting trough and allow for temperatures to rebound nicely back into mostly 50s over the plains and right back to near seasonal values. As the low to the south begins to retrograde back to the north a bit, some wrap around moisture of the deformation zone could catch the very far southeastern plains (mainly the southeastern half of Baca County) and result in a few snow showers by later in the afternoon and evening. However, much of the latest model guidance keeps this south of Colorado. The remainder of the CWA will remain dry. Saturday through Sunday... There will be an approaching mid to upper level wave approaching the region. Initially, downsloping winds out of the west will help warm up the plains and lower mountain valleys considerably in the morning, with most locations getting above the average seasonal temperature for this time of year. A cold frontal passage will occur by later in the morning and afternoon over the plains and shift winds to a NNE`ly direction with colder air advection in behind it. The timing of this front moving through at this time appears to be somewhere between 11 AM and 1 PM over the plains of the northern half of the CWA, and around noon to 2 PM over the southern half. As the axis of the wave continues to move over by later in the evening, the mid level instability, along with a saturated layer above the 700 mb level, will produce a few snow showers over the central mountains. On Sunday, the cooler air advected in from the north will knock down high temperatures right back around the seasonal temperature for most locations. As a ridge temporarily builds in behind the exiting trough and ahead of the next major shortwave upstream, it will allow for mostly clear skies and no precip expected anywhere in southeast Colorado. Monday through Wednesday... Deterministic models and ensembles alike are is relatively close agreement with another major shortwave trough propagating over the region throughout this timeframe in the forecast period. The ECMWF has the most amplification with the trough with a slightly more positive tilt to it, whereas the GFS and the Canadian are in closer agreement with the position and slightly quicker progression. The GFS also has the precip beginning the soonest over the Continental Divide during the late evening hours on Monday, with a surging cold front associated with it moving in during the early morning hours on Tuesday. This will likely produce some snowfall over the Palmer Divide around that time, and then move south with better chances of snow over the plains by later in the day on Tuesday. This system will bring in much colder air behind it, with some of the ensemble members suggesting highs in the low 20s for Colorado Springs on Tuesday. It is still too far out in the forecast period to know which model is most reliable, and is something that will need to be more closely monitored in the upcoming days. -Stewey && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 238 PM MST Wed Nov 23 2022 A potent upper trough will dig across southern Colorado tonight and continue to move south into central New Mexico through the day on Thursday, bringing snow and blowing snow to the southern mts late tonight and Thursday. While the Palmer Dvd will see some snow, strong northerly winds developing at COS and PUB this evening will likely keep VFR cigs and little to no precipitation expected at both terminals through the taf period. && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from midnight tonight to 5 PM MST Thursday for COZ074-075-087-088. && $$ UPDATE...GARBEROGLIO SHORT TERM...EHR/MW LONG TERM...STEWARD AVIATION...MW
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
730 PM MST Wed Nov 23 2022 .UPDATE... Issued at 730 PM MST Wed Nov 23 2022 Current surface analysis has cold front east of the forecast area, with brisk northwesterly winds lingering behind it across the region. Upper level analysis shows large scale trough over the Rockies, with low pressure developing at the base of the trough over southern CO. Energy on the northern periphery of the trough over central MT and WY is clipping northeast WY right now. Webcams and observations show a bit of light snow over Campbell County right now, and possibly over a few areas of the northern Black Hills and Wyoming Black Hills as well. The drier trends of the last few model runs appear to be coming true across the area, with any accumulations across these areas tonight expected to be on the light side, with mostly minor impacts. Only minor adjustments made to the forecast for the rest of tonight. Raised pops some for the rest of the evening across much of northeast WY and the northern Black Hills, but lowered QPF and snowfall amounts slightly for some areas. Most locations there will see less than an inch of snowfall, with amounts up to 2 inches possible over favored areas of the northern Black Hills where a brief period of favorable upslope enhancement is expected late this evening. Pcpn should start to taper off fairly quickly after midnight as drier air starts to advect into the region. Gusty winds will persist into the overnight as well, especially over the western SD plains, before decreasing some late tonight. && .DISCUSSION...(This Evening Through Wednesday) Issued at 140 PM MST Wed Nov 23 2022 The upper level trough is centered over the Rockies, pushing clouds into northeastern WY and the western Dakotas. South central SD remains sunny for now. At the surface, the cold front is moving through the CWA, producing breezy northwest winds behind. The strongest winds are just east of the Black Hills, where sustained winds are 20 to 30 mph and gusts are up to 40 mph. Temperatures range from the 30s across northeastern WY and the Black Hills to the low 60s across south central SD. Precipitation (mainly snow) is still expected to spread into northeastern WY and the Black Hills this afternoon and evening, but to a lesser extent. Thermal profiles still suggest only a brief period of saturation for those areas, and even less across western SD. The Froude number is only at or slightly below 1, which decreases confidence in much upslope snow. This is supported by the latest NBM 4.1, showing only a 20-40% chance of an inch of snow in the northern Black Hills. Therefore, have lowered PoPs and QPF/snow amounts further, now expecting 2 inches or less in the northern Hills, and less than an inch in northeastern WY. As for winds, it looks like the gustiest winds are occurring this afternoon just east of the Black Hills. The HRRR is showing a period of 40+ kt gusts this evening (which isn`t out of the question, looking at forecast soundings), but most other models keep winds lower. The ECMWF and GFS ensembles aren`t too impressive with wind gusts either, showing this evening`s gusts less than this afternoon`s, so opting to not issue a Wind Advisory. The upper low will split off from the main trough tonight and slide south, while upper ridging begins to move over the northern CONUS Thursday into Friday. CAA will keep Thanksgiving somewhat cool (30s and 40s), but much warmer air will advect into the region Friday, allowing for highs in the mid 50s to low 60s, which is near the NBM`s 90th percentile. A weak trough will flatten the ridge Friday night into Saturday. Cooler temperatures, breezy northwesterly winds, and possibly some light snow showers will follow its cold front on Saturday. Looks likely mainly northeastern WY and the Black Hills would be affected by any light snow, with minimal accumulations expected. Highs this weekend will be in the 30s and 40s. Looking into next week, models are showing a trough swinging from the Pacific Northwest through the Rockies by midweek, suggesting a potentially colder and snowier period. && .AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening) Issued At 455 PM MST Wed Nov 23 2022 An upper level disturbance and cold front will continue to pass through the region tonight. The main chances for light snow will be across northeast WY and the northern Black Hills area. MVFR/IFR conditions will become fairly widespread across northeast WY to portions of southwest SD during the evening, lingering into the overnight. Gusty northwesterly winds will persist, especially across the western SD plains. Gusts of 30 to 35 kts are expected at times, especially in the KRAP area and across portions of northeast WY. Winds and areas of light snow will taper off quickly late tonight, with VFR conditions and breezy northwesterly winds on Thanksgiving day. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ Update...26 DISCUSSION...Pojorlie AVIATION...26