Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/13/25


Area Forecast Discussion
National Weather Service La Crosse WI
525 PM CST Sun Jan 12 2025 .KEY MESSAGES... - Cold Airmass On Tap Through Tuesday/Tuesday Night. Wind Chills More Than 20 Degrees Below Zero Tonight & Monday Night In The Northern Half Of Forecast Area From Southeast Minnesota Through Central Wisconsin, Up To 15 Degrees Below Zero Elsewhere. Daytime Apparent Temperatures Remain In The Single Digits Above & Below Zero. - Increased West-Northwest Winds Above 30mph Into Early Monday Morning, Slightly Decreasing Near 25mph During Monday. && .DISCUSSION... Issued at 1130 AM CST Sun Jan 12 2025 Anomalous Cold: As the low continues trudging east, a rapid cool down is expected tonight. Cold front is draped meridionally through central Minnesota at 12.18Z. Even colder airmass upstream with low level temperatures of - 20C over south-central Canada on POES imagery, advecting due south from a surface low over southern Hudson Bay. High resolution and long term global forecast models have this area of minimum low level temperatures becoming more widespread and decreasing further through today. These low level temperatures near -25C may be record minimums compared to SPC RAOB climatology overnight into Monday morning. Increased West-Northwest Winds & Resultant Wind Chills: The anomalous cold steepens low level lapse rates resulting in increased west-northwest winds gusting above 30mph in the northern half of the forecast area from southeast Minnesota through western into central Wisconsin. Coldest temperatures will be collocated with these higher winds, resulting in bitter cold wind chills more than 20 degrees below zero. Low level CAA slightly weakens through Monday resulting in surface west-northwest wind gusts from 20 to 25 mph. The anomalous low level cold remains parked over the forecast area through Tuesday, perpetuating below zero wind chills through Tuesday night. Eventually the trough axis exits to the southeast allowing temperatures to increase near to above seasonable into the 20s and 30s for the latter half of the week. Temperatures again drop into the single digits into early next week. Precipitation Chances This Week: An upper level jet streak along northwest flow traverses the Northern Plains through the Upper Mississippi River Valley midweek. The polar exit region of the upper level jet streak places best ageostrophic ascent in central and northern Wisconsin. A short bout of snow will be possible primarily north of Interstate 94 as a result. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 525 PM CST Sun Jan 12 2025 CIGS: fog/stratus satellite imagery depicting a distinct north-south running line to the blanket of low clouds, moving steadily east. If speed holds, those would clear KRST by 03z and KLSE by 05z. However, some thin cloud streets were evident in vsby imagery west of there. With loss of heating these should diminish. A mix of opinions in how low saturation manifests through tonight into tomorrow - RAP says it will stay cloudy, HRRR some clearing, NAM scatters it out. For now, will follow the current satellite and add clearing in for later this evening. May need to adjust if these trends don`t continue. For Monday afternoon, shortwave trough drops across the region with 1000:850 mb lapse rates pushing 8-9 C/km. Should result in scattered clouds, but potentially a BKN deck with -shsn. Not much support from the variety of the CAMS models for this outcome (yet), so will hold with scattered for now. WINDS: will stay up from the northwest tonight through the better part of Monday, although should some decrease in sustained/gust speeds moving into tomorrow morning. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...JAR AVIATION...JAR
Area Forecast Discussion
National Weather Service Cheyenne WY
832 PM MST Sun Jan 12 2025 .KEY MESSAGES... - Cold temperatures, breezy northwest winds, scattered snow showers, and areas of blowing snow will continue through Tuesday. - A warming trend is expected for the middle part of the week with nocturnal strong winds possible early night/early morning in the typical gap areas. - Frigid air will impact the region over the weekend, with widespread snowfall chances Friday. && .UPDATE... Issued at 832 PM MST Sun Jan 12 2025 Temperatures are currently dropping off faster than models have expected in some areas. That`s to be expected in areas with clear skies,and efficient radiational cooling. However, with a thick cloud layer diving south, I`m reluctant to amend the temperatures too much since the clouds overhead will stabilize the temperatures some as some of the radiational heat is returned back to the surface. So in the grand scheme of things, I may be cooler than trending but the overall minimum temperature may still be accurate. Going into tomorrow, There is some disagreement with the high-res models on the general effects of the front. Some have backed off on the where the precipitation will be produced looking at composite reflectivity as well as the timing with some models delaying the wave by a couple hours. && .SHORT TERM /THROUGH TUESDAY/... Issued at 159 PM MST Sun Jan 12 2025 An upper-level closed low still spinning in central Canada will send vort max after vort max into Wyoming over the next several days. A weak upper-level disturbance/vort max will make its way into the area today, leading to the chance for snow showers across the area. Radar has been consistently picking up on light echoes from a convergence zone stretching in a line from Wheatland to Kimball. It is possible some light snow could be falling under these echoes, however, observations from under the band show flurries at best at two sites. As the afternoon progresses, the RAP does show a frontogenesis band setting up roughly in the same area, stretching from Douglas to Pine Bluffs. This is also likely where some elevated CAPE values will exist later this afternoon, which could lead to light snow in the aforementioned area. Other locations that could see snow include the high terrain. Northwest upslope flow could lead to a few inches of snow this afternoon and evening in the North Laramie Range and Snowy Range. Hi-Res guidance does show showers tapering off overnight. A stronger vort max will kick into the CWA on Monday as the upper- level low in Canada drops into the Great Lakes region. Given that there is decent mid-level frontogenesis across the northern and central portion of the CWA with decent mid-level moisture, snow showers could be possible across the CWA. Hi-Res guidance and the NBM do not show much in the way of PoPs across the forecast area, so went above guidance to at least add a mention of "slight chance" precipitation in the forecast. Given the cold air aloft with 700 mb temperatures around -14C, precipitation is expected to fall as snow since high temperatures will be in the 20s to low 30s. Aside from the snow, another concern to be aware of is elevated winds across the wind prones during the day Monday. A surface high strengthening over northwest Colorado will create an impressive MSLP gradient along and west of the Laramie Range. 850 mb CAG-CPR gradients will briefly rise over 50 meters Monday morning. This does lead to the question of will there be high winds? They certainly cannot be ruled out, especially around Arlington. However, did not have the confidence to issue anything at this time. Instead, did bump the winds up in the forecast to at least have elevated gusts over 40 MPH during the day. Tuesday looks like a repeat of Monday. Yet another vort max will traverse the CWA, this one looking even stronger than the last as it shows a little kink in the 500 mb height gradient. Once again, given the modest lift and decent mid-level moisture, models seem too dry. Decided to raise PoPs again across the CWA during the day Tuesday to account for any snow showers that may develop. Similar to Monday, the surface high in western Colorado will strengthen leading to another good MSLP gradient set up over the western CWA. As a result, decided to bump up the winds in the wind prones again. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Issued at 159 PM MST Sun Jan 12 2025 A brief warming trend with mild condition mid-week will quickly lead to an arctic outbreak by the end of the week into the weekend. Tuesday night into the day Wednesday will feature the upper-level trough moving off to the east as an upper-level ridge builds into the western CONUS. Northeasterly flow aloft will develop as strong anticyclonic vorticity advection at 500mb tilts the building ridge to the east. As the trough moves further to the east, taking the vorticity swath with it, the upper-level ridge will become more upright, rather than tilted, leading to northerly flow overhead. With dry, continental air being advected into the the mid- and upper- levels with this ridge, mountain snowfall will come to an end late Tuesday night with little to no precipitation expected throughout the day Wednesday and Thursday. Northerly to northwesterly flow at 700mb with further support the advection of drier air into the region and cutting off any remaining snow chances for the CWA. Temperatures on Wednesday will be fairly mild, with highs in the upper-20s to mid-30s west of the Laramie Range and upper-30s to mid- 40s east of the Laramie Range. Mostly sunny skies will lead to a very nice day across the region, as winds remain fairly calm, by Wyoming standards. On Thursday, the upper-level ridge will begin to flatten out, turning upper-level flow from the northwest to the west as an incoming Canadian trough pushes to the south. Further down at 700mb, a short wave will traverse to the northeast of the CWA, leading to 700mb winds turning westerly and a low-level jet around 45-50kts developing Thursday morning into the afternoon and evening hours. Craig to Casper 700mb height gradients increase into the low- to upper-70s with 850mb gradients around the low- to mid-50s. In response to this, a 10mb surface pressure gradient will setup from the Sierra Madre Range through the Laramie Range, leading to significantly funneling through the mountain gaps by Thursday morning. Surface gradients remain strong throughout the day Thursday with the 700mb jet strengthening throughout the day to 50 to 52kts. In house guidance is pinging a 60-70% chance for high winds Thursday into the day Friday at Bordeaux and Arlington. GFS Omega fields also support the potential downslope wind event, with strong downward omegas across the Snowies and the Laramie Range. Overall, looks to be a favorable setup for high winds, especially with westerly winds dominating throughout the atmosphere. A benefit to these winds will be downslope warming leading to high temperatures in the low-40s to low-50s east of the Laramie Range and mid-30s to low-40s west of the Laramie Range. While it will be windy, it looks to be another nice day Thursday with mostly sunny skies. Strong winds are expected to die off fairly quickly Friday morning as a strong cold front surges to the south across the CWA. The upper- level Canadian trough will continue to push southerly into the Pacific Northwest by late Friday morning with the trough axis overhead by Saturday morning. The upper-level trough has origins from the northern reaches of the Canada, leading to very cold, arctic air being entrapped into the flow. As this trough pushes into the CONUS, a very strong cold front will surge into the CWA from the north and rake across the region from north to south through the morning and early afternoon hours. Expecting the high temperatures on Friday to occur shortly after midnight, as not much daytime heating will take place prior to the cold front surging through. Current forecast high temperatures on Friday at in the upper-20s to upper-30s. 700mb temperatures will tank from the 2 to 4C range on Thursday into the -10 to -12C range by Friday afternoon. A reinforcing blast of arctic air in the form of an arctic front will also pushing into the region Friday evening into early morning Saturday, resulting in 700mb temperatures in the -17 to -20C range by Saturday morning. One thing to note from the 12Z run of the GFS and ECMWF is that the ECMWF suggests a slightly colder blast of air with the arctic front, while the GFS is a degree or two warmer. This is the first real discrepancy seen between the long range models since this system began to take shape, however, the differences are still only around a degree or two at 700mb. With the initial cold frontal passage, snow showers will develop along the front as it pushes through the region and a strong frontogenesis band is progged to take shape ahead of the cold front. Since this cold front will be fairly quick passing, not much snow accumulation is expected with it at this time, but this may change if the cold front speeds up or slows down with future model runs. In addition to this, the secondary arctic front will keep snow showers around much of the day Saturday and even into Sunday as residual lift remains across the region in addition to frontogenesis bands. Saturday and Sunday will both be frigid as very cold 700mb temperatures remain in place due to the reinforcing shot of arctic air supplied by the secondary arctic front. Saturday will feature 700mb temperatures in the -16 to -20C range, with a slightly colder setup in the ECMWF and a slightly "warmer" setup in the GFS with differences of only about 2C. This results in surface highs in the single digits to low-teens. With surface winds remaining fairly stout behind the arctic fronts, it will feel closer to -5 to -10F across the region Saturday afternoon. Sunday is where more discrepancies between the GFS and ECMWF take place. The GFS suggests 700mb temperatures in the -15 to -20C range from the southwestern portion of the CWA through the northeastern portion with the coldest 700mb air just barely encroaching into far northeastern Dawes County and eastward into South Dakota and central Nebraska. The ECMWF on the other hand has the coldest air further southwest along a line from approximately Casper southeasterly through central and eastern Laramie County and points east. 700mb temperatures range from -20 to nearly -30C in the far northeastern corner of Dawes County. These differences lead to a nearly 10 degree difference in forecast high temperatures for Sunday across the entire CWA, with the ECMWF suggesting a high of -2F for Cheyenne and the GFS suggesting a high of 7F. While these differences are enough to result in several degrees of temperature differences, one thing is fairly certain: it`s going to be very cold on Saturday and Sunday. With the colder scenario in the ECMWF and the slightly "warmer" scenario in the GFS, decided to blend in the 10th percentile NBM and adjust down a few degrees from there. Probably could have blended to the 5th percentile, but decided not to go too aggressive at 7 days out. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 455 PM MST Sun Jan 12 2025 Quiet weather expected tonight and Monday with diurnal gusty winds for most terminals. North to northwest flow aloft will continue over the area as another weak disturbance aloft moves across the region on Monday. Additional snow showers are possible but will likely be isolated Monday afternoon. HAZARDS/WEATHER TRENDS: VFR conditions will continue tonight and Monday with CIGS fluctuating between 5k to 10k feet, mainly north of Interstate 80. Gusty winds will subside early this evening, by 02z, with relatively light winds overnight. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...MM SHORT TERM...SF LONG TERM...AM AVIATION...AM
Area Forecast Discussion
National Weather Service Dodge City KS
508 PM CST Sun Jan 12 2025 .KEY MESSAGES... - Dry, calm week for SW Kansas until the weekend. - Chances (10-70%) for light, patchy fog the next few mornings for the eastern counties. - Mid-week warmup before a cold air blast headed into the weekend. && .DISCUSSION... Issued at 223 PM CST Sun Jan 12 2025 A fair amount of snowpack remains in the eastern half of the area as noted on GOES visible channels covering most of the area east of Highway 283. Weak cold advection was probably negating the abundant insolation as the high as of 1:30 pm was still in the upper 30s across this snowpacked region with a few mid 40s in the southwest. Surface high pressure will overspread central Kansas overnight, leaving the area under light surface winds. Breezy north winds with gusts to around 20 knots during this mid afternoon will decouple quickly around 4 pm as sustained winds fall light and out of the south southwest. Point forecast soundings from the HRRR shows very dry air above the surface with dew point depressions falling to a couple of degrees by 2 am. With good radiational cooling and the recent melted snow on the ground, conditions will be favorable for fog development. The chances for dense fog ( one quarter mile or less) are only about 20-40% from around Dodge City to Liberal an points east or anywhere along highway 283 corridor. Most of the fog would more probably be light in the 1-4 SM range as the HREF probabilities here area about 50-70% Lows overnight will be most in the mid teens with potential for slightly colder temps over the snow than over the south and western counties. A repeat of Today is in store for Monday afternoon before a incremental warmup into the 50s on light west winds plays out into the end of the workweek. Similar to yesterdays ensemble runs - the ECMWF 24 hour QPF multi-run mean, for Sunday into Monday, continues to focus a 0.5 - 0.10 precipitation episode which has been consistent for at least a dozen model runs. Large uncertainty exists as the GFS continues to be dry during the same period, for the last 4 runs and about 50% of the previous six runs. Monday and Tuesday also appear to be the coldest of the next couple of weeks. Lows Monday and Tuesday nights point to teens and single digits with no account for impacts due to wind. The 8-10 day CPC outlook, in addition to basically conus wide colder than normal conditions, paints a 40 to 50 percent chance of wetter than normal conditions as well for January 19 25) . && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 505 PM CST Sun Jan 12 2025 A surface high will move in tonight reducing the winds to below 12 kts and the winds should stay 12 kts or less through the time period. In general we should have VFR flight category for all terminals however areas that still have snowpack could see some areas of fog develop after 06Z-15Z. This fog could affect DDC and HYS however ensemble probabilities of surface visibility <1 SM is at 0% and ceilings dropping to MVFR flight category is around 15-20%. && .DDC WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Russell AVIATION...Tatro
Area Forecast Discussion
National Weather Service Hastings NE
541 PM CST Sun Jan 12 2025 .KEY MESSAGES... - 7-day forecast precipitation overview: In the shorter term, particularly Mon evening-overnight will carry some "sneaky" light snow accumulation potential (AT LEAST flurries) especially near/north of I-80. In the longer term (but still of lower confidence), will need to keep an eye on the late Fri night-Sat time frame for another chance for at least light measurable snow. - 7-day forecast temperature overview: We`re definitely gonna ride some hills/valleys, as we transition from generally near- normal temps Mon-Tues, to above normal Wed-Fri (especially Thurs), to a fairly significant plunge back into Arctic cold next weekend (especially Sunday). - At least for now, our Hazardous Weather Outlook (HWOGID) remains void of any mentionable hazards, as the aforementioned snow chances still appear too low impact and/or low confidence, and the aforementioned cold plunge mainly arrives JUST beyond the HWO time frame (which currently only goes through Saturday). && .DISCUSSION... Issued at 430 PM CST Sun Jan 12 2025 -- PRIMARY 7-DAY FORECAST CHANGES/UNCERTAINTIES/POSSIBLE WEAKNESSES: -- The main changes from our previous (overnight) forecast package...and none of which were "super significant"...include: - High temps for Monday were nudged up 2-4 degrees most areas - Low chances for light snow and/or flurries were increased a bit for Monday evening- overnight (perhaps not enough?) - Slight snow chances were expanded to a bit more of our forecast area (CWA) for late Fri night-Saturday (but probably not enough of our area?). -- As for uncertainties, the main two that come to mind are: - Is our forecast warm enough for especially Wed-Thurs? Assume no pesky cloud issues, both of these days (esp Thursday) have the potential to "overachieve" as Thursday could bring the first 50s of the month to much of our area (goodbye lingering snow cover!). - Are we hitting the light snow/flurry potential hard enough for Monday evening-overnight in our northern/central CWA? While nearly all models clearly show that the MAIN potential for any accumulating snow should focus slightly north-through- northeast of our CWA, more often than night pesky light snow/transient snow showers end up "invading" a bit farther south-southwest than expected (as suggested by last few HRRR runs). -- 7-DAY FORECAST CHRONOLOGICAL DETAILS: - CURRENT/RECENT WEATHER SCENE AS OF 330 PM: In the wake of a few spotty overnight-early AM snow showers that even left a light dusting in places such as Grand Island/York, the daytime hours have played out very much as expected. Most noticeably, mid-afternoon temperatures are running a solid 10-20 degrees colder than Saturday afternoon in the wake of a fairly strong cold front. That being said, there is currently a 10-15 gradient (difference) across our CWA, ranging from only near-20 far north-northeast, to mid-upper 20s central (including Tri Cities) to low-mid 30s southwest. Despite widespread afternoon sunshine, the presence of a markedly-colder airmass and very brisk northwest winds (commonly sustained 15-25 MPH/gusting 15-30+ MPH) are really putting a bit in the air, with 3 PM wind chills only +5 to +20 across most of our CWA. Official calendar day high temps for today will be somewhat "misleading", as especially the north half of our CWA actually saw their highs very early this morning before the cold front crashed through. In the mid-upper level scene, water vapor satellite and short term model data depict a very "troughy" pattern dominating much of the United States, with one of the more prominent embedded low pressure systems centered to our north over Manitoba/Ontario. - THIS EVENING-OVERNIGHT: Although probably cannot totally rule out a few rogue flurries especially over a few of our far west-southwest counties post- midnight (not in official forecast), confidence is overall-high in a snow-free, but much-colder night (versus last night). Fortunately, winds will really ease up toward sunset and especially post-midnight (only around 5 MPH from mainly the west). Sky cover is a bit tricky, as although we`ll start the night very clear, especially the southwest half of our CWA could see a deck of semi-low clouds swing through late in the night. The variable cloud cover and light westerly breezes cast at least modest uncertainty on actual low temps tonight, but made only minimal change aiming most of our northeast half (along with far southeast) into the 5-10 range, with much of our southwest more so 10-15 where clouds could hold things up a bit. Last but not least, there are some subtle signals of patchy fog potential in some model data overnight mainly over the deepest snow cover in our extreme southeast CWA (Mitchell County area), but this signal is just not high enough at this time to justify formal forecast inclusion. - MONDAY DAYTIME: Although probably cannot rule out some flurry activity flirting with our extreme northern counties mid-late afternoon, confidence is high that the vast majority of our CWA gets through sunset snow-free. Cloud-wise, like today the morning could see some lower clouds flirt with our northern/eastern zones, while the afternoon brings a gradual increase in mid-high level clouds (especially north). So all in all, a generally partly cloudy day overall. At the surface, winds will be weaker than today...generally 10-15 MPH (a few gusts near 20) out of the west-southwest. Assuming clouds are not more abundant than expected, the weak warm air advection on these westerly breezes should boost afternoon highs 5+ degrees warmer than today in most (not all) areas. Per latest guidance, nudged highs up 2-4 degrees from previous forecast most spots, but varying from upper 20s/near 30 far east...low-mid 30s central...upper 30s/near 40 far west. - MONDAY EVENING-OVERNIGHT (light snow potential): In the mid-upper levels, a fairly well defined disturbance/low pressure system will drop southeastward from the Upper Midwest to the Lower Great Lakes region, which will force a "backdoor" cold front south-southwestward into our CWA at the surface. The million dollar question is how prevalent light snow showers/flurries become within our CWA as we realize some halfway decent saturation of the low-mid levels (and temperatures in southward-sinking lower stratus clouds at least getting slightly into the temperature range favorable flurry/light snow formation/around -10C). Larger scale models (NAM/GFS/ECMWF) remain fairly insistent that the MAIN axis of light measurable snow should reside at least barely north-through-northeast of our CWA in north central/northeast NE. However, higher res models (particularly HRRR) are fairly insistent that at least transient bands of light snow showers (AT LEAST flurries) will probably extend at least as far south into our CWA as roughly a Lexington-Hastings-Geneva line, with areas mainly north of a Loup City-Grand Island-York even in line for perhaps a few tenths of an inch of legit snow accumulation. At least for now, have increased the areal coverage of flurries/light snow shower potential farther southward into our CWA versus previous, and obviously there is room for further expansion/higher chances (PoPs) in later forecasts. Obviously even if we do see some minor snow accumulation (again mainly north), it won`t be a "major event" (and winds won`t be a big issue either...mainly only 5-10 MPH). THAT BEING SAID, this could cause some slick spots for Tues AM commute and thus why this forecaster is also concerned about "downplaying" it too much. Temperature-wise, the presence of what should be quite a bit of cloud cover (especially central-northeast) and the aforementioned light (but not calm) breezes should keep things from dropping too far, and have lows ranging generally 8-12 northeast, to 14-18 southwest. - TUESDAY: Although not in our current forecast, there are hints in higher- res data (particularly NAMNest) that some flurries could be around...especially under any potential lingering/stubborn low clouds "leftover" from Mon night. Any such lower clouds should gradually depart from west-to-east as lower level flow turns more westerly, but our current "partly cloudy" forecast most areas could prove a bit optimistic (especially east). Given the cloud cover uncertainty, confidence in high temps is a little shaky, but no matter there should be a good 10-15 degree gradient across our CWA, currently aimed from mid 20s far east...to near-30 central...to mid-30s to near 40 west. - WEDNESDAY-THURSDAY (warming up!): These are most definitely the days of the week for those looking for a bit of a January warm-up! The NAM/ECMWF/GFS are all in great agreement that large-scale troughing will depart off to our southeast, allowing broad west-northwesterly flow/weak ridging to spread over our region. At the surface, predominantly west- southwesterly breezes will foster a nice temp bump. Would not be a bit surprised if our official forecast is not yet aimed warm enough (especially for Thurs), but at least for now have highs upper 30s-mid 40s most areas Wed, and mid-upper 40s most places Thurs (low 50s far southwest) This would mark the first 50s of the month within our CWA! Needless to say, these days should wipe out the vast majority of any lingering snow cover, even over the deepest snow in our southeast. - FRIDAY-SUNDAY (crashing back down!): Above all else, get ready for a temperature tumble! Aloft, the next large-scale trough will swing through the region from the northwest, but this time the associated surface cold front feature more of an "Arctic punch". Obviously some timing uncertainty with the initial frontal passage Friday, but at least for now it still looks like a reasonably-mild day with highs mainly low 40s. Then Fri night-Saturday temperatures take a tumble with highs Sat only in the 20s. Although FAR from a sure thing at this point, there appears to be at least a slight increase in light accumulating snow potential too for late Fri night-Saturday daytime (these chances may need hit harder in later forecasts?). Even so, latest ECMWF ensemble suggests minimal accumulation under 1", so not a "major storm" either. As the colder air deepens, Sunday then appears quite frigid, with high temps only teens. Wind chills will surely become a concern as well, as VERY preliminarily we have values as low as -10 to -15 for late Sat night-Sun AM (technically just short of Cold Weather Advisory criteria, but could trend worse with time). && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 537 PM CST Sun Jan 12 2025 For KGRI/KEAR Airports: Dry weather expected through this TAF period. Kept ceilings VFR as well, though it`s not out of the question some scattered clouds working through the area late tonight into tomorrow could make it close call with MVFR ceilings. Current NW winds expected to turn westerly overnight, remaining that way through the end of the period...speeds look to top out around 10-15 MPH. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...Pfannkuch AVIATION...ADP
Area Forecast Discussion
National Weather Service Goodland KS
232 PM MST Sun Jan 12 2025 .KEY MESSAGES... - Very low chance for fog (5%) across the east Monday morning; slightly better chances (10-15%) Tuesday morning across the east as well. - Above to much above normal temperatures are forecast to return next Wednesday through Friday. - Confidence continues to increase in Arctic air returning next weekend with dangerously cold temperatures. Snowfall potential remains as well. && .SHORT TERM /THROUGH WEDNESDAY NIGHT/... Issued at 1242 PM MST Sun Jan 12 2025 NNW flow remains across the area resulting in mainly sunny skies across the area with the only exception being a weak short wave leading to a corridor of low to mid clouds around 2500-8000 feet above ground level. This shortwave is forecast to move down along the higher elevations of east Colorado which may lead to the potential for some flurries or light snow showers across eastern portions of Cheyenne county Colorado overnight. The last few runs of the HRRR has been trying to suggest an isolated heavy snow shower may try to form out of this area of cumulus around roughly the Idalia area and move towards Goodland and the I-70 corridor around 22-00Z. Have also noticed an uptick in mid level moisture on the RAP as well during this time frame. Overall not completely sold in anything occurring due to dew point depressions being around 15-20 degrees anything if something should develop would probably fall as virga or flurries. On the other side, assuming the HRRR is right and is onto something, soundings do show surface CAPE around 40 j/kg, semi steep lapse rates around 7-7.2C which may provide enough instability for a snow squall to occur. At this time confidence in that occurring is 5 percent or less. As for the fog potential, confidence has decreased due to winds failing to be out of the favored ENE direction for a prolonged period of time; there is also some concern about cloud cover increasing overnight that would help mitigate the potential. As a result of this I have removed from the forecast, it does need to be mentioned that the NAM remains the most aggressive with visibility reductions but with the NAM known to have a moist bias I`m still thinking that the fog potential is unlikely. Confidence in fog formation is around 5% currently. Low temperatures for the night are currently forecast in the upper single digits to the upper teens. If cloud cover does overachieve tonight then low temperatures may need to be upped a few degrees. Monday, looks to be a virtually similar pattern as today but with more of a westerly wind component have nudged temperatures a few degrees due to additional warming by downsloping winds. High temperatures at this time are forecast in the upper 30s to mid 40s across the area. Winds for the day are forecast to be lighter as a weak surface trough develops over the area keeping winds around 10 mph. Slightly stronger winds gusting near 20 mph are possible mainly across the east in response to a strong low pressure system across the upper Great Lakes. Monday night watching as a back door cold front affects eastern portions of the area as the low pressure system across the Great Lakes moves to the east and the ridge axis of a surface high affects the area. This is typically a fairly decent pattern for fog development but will hold off on introducing into the forecast at this time due to any potential shifts of the ridge axis as there is still potential it may end up further east of the area. Tuesday, a continued warming trend is still forecast but may depend on how quickly and/or the positioning of the above mentioned surface high as fog/stratus may linger. Currently gave high temperatures forecast in the 40s area wide but may need to be lowered across the east if confidence increases enough in the potential lingering of fog/clouds. The main change in the forecast is some increasing mid level moisture associated with a quick moving disturbance from the Nebraska Panhandle/eastern Wyoming. The RAP has the mid level moisture approaching the NW portion of the county warning area by the latter hours of the afternoon. Some flurries or light snow showers are possible but with the dry air at the surface I have my doubts currently that anything will reach the surface. Have opted to go silent pops and cut out the qpf that was loaded into the forecast for that timeframe due to these concerns. Wednesday, warming trend will continue as overall good consensus with the surface high moving out and the westerly downsloping winds continue. Winds at this time do appear to be slightly stronger gusting 15-25 mph, the NAM has a stronger 850mb jet around 35 knots working into northern portions of the area so there is potential that the winds may need to be tweaked up if more guidance starts picking up on this. High temperatures for the day are currently forecast in the low 50s but if enough mixing can occur then temperatures may be able to overachieve a little more than currently forecast. If that is the case then we may need to keep an eye on some low end fire weather conditions especially if the 850mb jet that the NAM was suggesting does end up panning out. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Issued at 1235 PM MST Sun Jan 12 2025 Thursday...a clear sky remains in the forecast. It also looks to be rather warm for mid January (normal high temperature in the lower 40s) with GFS/GEM/ECMWF 850mb temperatures in the 8C to 10C range. Typically, this would support high temperatures in the 50s and 60s. Presently, high temperatures are forecast to be in the 50s to near 60, warmest along Highway 27. This is similar to the UKMET 2m temperatures and NBM probabilities of temperatures greater than 60 degrees (near 30%). Low temperatures are forecast to be in the 20 to 25 degree range, also above the normal low in the middle teens. Friday...cloud cover increases during the afternoon and overnight hours from northwest to southeast as an upper level trough axis and cooler air with the leading edge of an arctic cold front move in. Northerly winds gusting 25 to 35 mph are forecast during the day. There is now a 20%-50% chance for light snow overnight, highest chances across eastern Colorado as a large swatch of moisture in the 850-500mb layer moves into the area from the northwest. With favorable temperatures and moisture throughout the dendritic layer and the arctic airmass moving in, it should be pretty easy to generate some snowfall along with minor accumulations. High temperatures are forecast to be in the lower to upper 40s, similar to the NBM mean temperature forecast. The spread in the high temperature guidance from the NBM model has decreased a bit compared to 24 hours ago with values in the 8 to 10 degree range, so anticipate some changes in the temperature forecast in the coming days. Low temperatures are forecast to be in the 10F 10 16F range with wind chill readings lower to middle teens with wind chill readings in the single digits above and below zero. Saturday...it appears that the swath of moisture bringing snow to us Friday night gradually exits the area during the day from north to south with perhaps another round of light snowfall overnight. However, with favorable temperatures and just enough moisture in the dendritic layer within the arctic airmass, it wouldnt take much moisture to produce some flurries or light snow showers. Presently, there continues to be a 20%-50% chance for light snow (highest pops across eastern Colorado) during the day with a 20%-40% chance overnight. Some minor additional snowfall accumulations seem reasonable. High temperatures are forecast to be in the 20s. This is in line with GEM/GEFS/GFS/ECMWF/UKMET 2m temperatures as well as NBM mean max temperature. Low temperatures fall into the single digits above and below zero with wind chill readings in the 5 below to 15 below zero range, coldest across eastern Colorado. Sunday...arctic high pressure continues strengthening over the with even colder air pouring into the area. The ECMWF model is the coldest with high temperatures in the single digits above zero while the GEM model shows single digits to middle teens. The GFS isnt quite as cold with teens and 20s. The NBM and current forecast is for highs to be in the 10 to 20 degree range, coldest across eastern Colorado. This is similar to the temperatures we had back January 5 of this year. Low temperatures are forecast to be in the single digits below zero. Per GFS/ECMWF models, there appears to be another round of sufficient moisture moving through the area from the northwest through the period, especially overnight. This would likely lead to some additional light snowfall. There is currently a 20%-30% chance for snowfall during the day with lesser chances overnight. If trends continue, the overnight hours would need pops to be increased. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 229 PM MST Sun Jan 12 2025 VFR conditions remain forecasted for each terminal. Corridor of cumulus continues at KGLD but are anticipated to remain around 060. NW winds will become more westerly this evening around 5-10 knots sustained. Continuing to monitor the potential for some stratus around KMCK Monday morning but confidence in a flight category reductions still remains to low to include in the TAF at this time. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ SHORT TERM...Trigg LONG TERM...99 AVIATION...Trigg
Area Forecast Discussion
National Weather Service Green Bay WI
556 PM CST Sun Jan 12 2025 Updated aviation portion for 00Z TAF issuance .KEY MESSAGES... - Arrival of arctic air combined with gusty west winds will lead to bitterly cold wind chills from 15 below to 25 below zero over much of the area on Monday morning, and also Monday night into Tuesday morning. - As the colder air arrives this evening into Monday any lingering wet spots on roads, bridges, or sidewalks may freeze and become slippery. Motorists are urged to drive with caution this evening into Monday morning as roads that appear wet may be slippery. && .DISCUSSION... Issued at 240 PM CST Sun Jan 12 2025 Short Term...Tonight and Monday Surface obs and RAP analysis show a low pressure center over the western WI/UP border this afternoon. This low is producing scattered areas of light snow across northern WI, while areas south of highway 29 are seeing sporadic periods of snow mixed with freezing drizzle. Precipitation will come to an this evening from southwest to northeast dry mid-level air moves over the region. Will need to monitor an area of light snow moving across eastern MN this afternoon that may reach central WI this evening which may warrant and increase in PoPs, but not confidence this area of precip will hold together as it moves through western WI. Otherwise the threat to any lake enhanced snow in Door Counties has ended with winds now going offshore. As the precip come to an end attention then turns to a blast of much colder air moving into the region tonight. RAP analysis shows 850mb temps of -15 to -20 degrees already pushing into NW MN where surface temps have already fallen below zero. Low temperatures overnight are expected to fall into the single digits below zero north and west of the Fox Valley while areas in the Fox Valley and near the lakeshore will see lows in the middle single digits above zero. Increasing northwesterly winds gusting around 25-30 mph will bring wind chills down into the -15 to -20 degrees range Monday morning, which would fall just short of Cold Weather Advisory criteria. With the arrival of the much colder air any linger wet spots on roads or sidewalks will likely freeze and become slippery. Monday will trend much mostly dry across the region, with only low end (20-30%) chances for light snow across far north-central WI as moisture wraps around a stalling low pressure system over eastern Ontario. Long Term...Monday Night Through Sunday Potential for hazardous weather in the long term is due to bitter cold wind chills early this week. Snow chances remain on the low side, with primary risk for areawide light snow late Wednesday into Wednesday night, then maybe Friday night into Saturday. Temps the first part of this week will be cold, before moderating. Even colder conditions are expected beginning later next weekend and into the following week. Temperatures/Wind Chills: The lowest wind chills will occur Monday night into Tuesday morning. Gusty northwest winds up to 20 mph combined with temps in the zero to 5 below range will result in wind chills 15 to 25 below zero, lowest over central WI. As upper trough crosses the upper Great Lakes, clouds may impact especially northern WI, which may affect temps, wind chills. Not enough confidence in this to raise temps any though. After another chilly day on Tuesday (though not as cold as Monday), cold temps expected again Tuesday night into Wednesday morning. Seems a good setup for radiational cooling with PWAT min coming across and clear skies, light winds. Nudged lows down toward EC, Canadian with coldest readings now 5 to 10 below central to north-central. Light winds so not looking at any issues with wind chills. Temps begin to bounce back on Wednesday with highs mainly in the 20s. Warming trend then really takes hold late this week as primary sfc low tracks well to north across Manitoba and Ontario, leaving western Great Lakes within warmer SW return flow. High temps as early as Thursday will reach above freezing, with similar temps into Friday. First in a series of cold fronts arrives Friday night into Saturday. Differences on strength of initial push of cold air, but certainly will not be as warm as Thu/Fri, with all areas back below freezing by Saturday afternoon. As arctic sourced high pressure over 1050mb builds into the northern Plains, even colder air arrives next Sunday. Highs will range from around zero far north to the lower teens Fox Valley to the lakeshore. Temps could even be steady or fall. Lowest wind chills will be over central WI. Snow Chances: Not looking at much in the way of widespread snow chances. Greatest chance, and still not that high, could be late Wednesday into Wednesday night as warm air advection aloft gets underway and there is a signal that light snow could impact north half of the cwa. Canadian most favorable for this. LREF ensembles suggest anything more than an inch would be a stretch. Ticked pops up along the Upper Michigan border with slight chances as far south as highway 29. Otherwise, main chances of snow will be tied to lake effect Monday night into Tuesday, then again Friday into the weekend over the far north. NBM pops have trended down with system grazing us to the south and southeast later Friday night into Saturday. Main area impacted from that snow would be far east-central WI. Overall if you are looking for much snow this week, the trend is *not* your friend. Outlook beyond next Sunday: Coldest air of the season is poised to impact our region just beyond the range of this forecast. H85 temps on some models drop to -30c or colder but even ensembles are showing at least -25c. Even with the more "moderate" value, it seems likely that temperatures starting late Sunday could stay below zero well into early the week of Jan 20th from central WI to north central WI. Fox Valley to lakeshore locations could reach zero to 5 above, but that would be it. All areas will be well below zero for lows. Even this far out, seems pretty certain we will be dealing with cold weather headlines with the main question being whether they will be advisories or warnings. && .AVIATION...for 00Z TAF Issuance Issued at 555 PM CST Sun Jan 12 2025 Poor flying conditions will continue into tonight, with mainly IFR/MVFR ceilings/visibilities expected as low pressure slowly tracks across the Great Lakes. Any freezing drizzle over eastern WI looks to end early this evening as the colder air arrives and moisture decreases. However, some flurries and snow showers are expected to continue into tonight. Lots of clouds upstream despite the colder/drier air, but also some areas of clearing. Will lean toward more cloud cover on Monday, but the downsloping winds should allow for some clearing, especially across eastern WI. Cold air advection will keep gusty winds across the area tonight into Monday, with gusts of 15-25 kts expected, with higher gusts to 30 kts possible at times. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....GK/JLA AVIATION.......Bersch
Area Forecast Discussion
National Weather Service New Orleans LA
544 PM CST Sun Jan 12 2025 ...New AVIATION... .SHORT TERM... (This evening through Monday night) Issued at 224 PM CST Sun Jan 12 2025 Starting off with mid/late afternoon, as mentioned in the morning update, our next weather maker is getting itself together offshore coastal SE TX as a weak surface low. This is in association with a weak shortwave impulse riding progressive SW/NE flow aloft from the Mexican Plateau into the far NW GOMEX. Downstream divergence/attendant lift as well as low/mid-level moisture advection has led to widespread clouds across the region, with a few light echoes from KHDC radar trends. The 12Z KLIX RAOB was very telling about where the moisture layer resides (roughly around H8 to H7) sandwiched between two very distinct dry layers in the troposphere. Meaning, as greater dynamic ascent approaches the area (corresponding with slow/steady sfc low strengthening), this layer will precipitate greater as we go on into the evening hours helping to wetbulb the dry layer below it by evaporative cooling. All models are in agreement that we`ll continue to see stratiform precipitation spread across the region this evening into tonight, and had no trouble going 90-100% PoPs timed by NBM hourly guidance which looks good overall. Given the northern proximity of SE LA/S MS in correlation with the northern Gulf low, not anticipating any thunderstorm activity and in fact, with the airmass largely stable and non-convective (over land, could see thunderstorms near the coast and marine areas), rain totals could land more towards the lower side of forecast QPF. Noticed this trend recently in the HRRR today compared to yesterday. Thinking rain totals of 0.5-0.75" will be pretty common but some 1-1.25" (isolated higher) totals can`t be ruled out. Generally speaking, a quiet, chilly rainy night is ahead with very little impact. Otherwise, as for temperatures, went colder for highs today from the morning update but it looks like it wasn`t cold enough, as another drop was required given temperature trends. It`ll be chilly tonight, with lows in the 40`s (north) to 50`s (south) but didn`t adjust temperatures going into daybreak much as this looks on track. Getting into early Monday, the rain will become lighter with time, perhaps from a light rain to drizzle going into mid-morning from west to east, as the surface low departs the area. As the low continues east, our winds will transition more from the NE and increase becoming occasionally breezy during the daytime. Next to closely monitor will be the low stratus deck overnight into tomorrow. Model soundings/guidance strongly suggests remnant 925mb layer moisture on the back side within persistent CAA regime. While the exact degree of cloud cover is in question (for example, more spotty stratocumulus versus solid-deck stratus), feeling confident that clouds will hang around and with the aforementioned CAA pattern. Felt obligated to nail MaxT`s lower yet again towards a 1/3 10th percentile and 2/3 25th percentile blend putting many areas topping out in the upper 40`s to low 50`s. We`ll have to just keep a close eye on cloud cover trends if any further adjustments are needed but overall, wanted to go ahead and get on board with atleast a 5-6F drop in suggested NBM deterministic values. Eventually clouds to thin out some going into Monday and into Monday night, but it`ll be turning cold yet again with lows dropping back again to freezing for mainly the Florida Parishes north of I-10/12 and SW MS. While we`ll see radiational cooling at work that morning, sfc/low-level winds may remain just enough elevated to allow mixing to offset maximized radiational cooling processes (and to a smaller degree, high clouds). Thus, didn`t make any notable adjustments to lows as everything looks plausible given the meteorological setup. Only adjustment was a notch to MinT`s down slightly in the Pascagoula/Pearl River Drainage basins more protected from the winds. Additionally, due to winds remaining a bit more elevated (displaced from the surface high still to the NW), min wind chills do get down into the upper 20`s to mid 30`s for the I-10/12 corridor, with low/mid 20`s possible for SW MS. Not within Cold Advisory criteria with just yet, but will keep an eye on guidance. KLG && .LONG TERM... (Tuesday through Saturday night) Issued at 224 PM CST Sun Jan 12 2025 The first couple of days in the long term are fairly uneventful with an overall zonal 500mb pattern across much of the Deep South with upper level winds generally due west to east. This split-flow pattern is the result of two upper level storm systems: one that will drop south out of Canada and across the Great Lakes and another that will form and meander close to Southern California. Meanwhile, at the surface, high pressure and northerly winds will remain in place through mid week. This will keep temps near to slightly below average Tuesday and Wednesday, with clouds decreasing as drier filters in from the north. Thursday into Friday, the pattern will shift as the Canadian Low deepens and the west coast low swings across the Desert SW. Weak ridging will develop in response and the surface high will shift east allowing southerly winds to return. High temperatures will warm from the lower 60s Thursday afternoon into the mid 60s north to upper 60s/near 70 south on Friday. But with the increasing warmth also comes the return of Gulf of Mexico moisture. Clouds and rainfall chances will steadily increase Friday afternoon in the overnight hours. Saturday has a small chance for some rumbles of thunder mixed in with the showers if there is enough instability. Being towards the end of the period, there will likely be some tweaks over the next few days. Rainfall amounts look to be on the order of 1 to 2 inches. && .AVIATION... (00Z TAFS) Issued at 540 PM CST Sun Jan 12 2025 Southern terminals are already at IFR or lower conditions (primarily ceilings), with far northern terminals still at VFR. Expect that in the next 2-3 hours, all will be at IFR or lower conditions, and will stay there until at least mid morning Monday. Could see some improvement to MVFR at that time, but any improvement to VFR conditions is unlikely before late afternoon Monday, and that may be too quick. && .MARINE... Issued at 224 PM CST Sun Jan 12 2025 A gulf low continues to develop over the northwestern Gulf this evening, which will approach the area overnight tonight. Expect widespread showers and a few thunderstorms with this system before exiting to the east mid-morning Monday. Winds out ahead of this low will continue to increase this afternoon/evening out of the east at around 15-25kts, with a Small Craft Advisory in effect beginning at 6PM today. Once the low passes to the east, winds will shift more from the northeast becoming strong yet again early Monday thru atleast Tuesday. Waves/seas will respond to 3-5ft for nearshore/protected waters to 5-9ft for outer Gulf waters following progressive offshore fetch. Surface high pressure builds into the area mid/late-week with calm conditions expected until the next storm system and frontal boundary approaches marine areas next weekend. && .PRELIMINARY POINT TEMPS/POPS... MCB 42 49 29 52 / 100 20 0 0 BTR 48 54 34 56 / 100 10 0 0 ASD 48 54 33 56 / 100 20 0 0 MSY 50 54 40 53 / 100 10 0 0 GPT 47 52 33 54 / 100 40 0 0 PQL 46 54 32 57 / 100 40 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...Small Craft Advisory until noon CST Tuesday for GMZ530-532-534- 536-538-550-552-555-557-570-572-575-577. MS...None. GM...Small Craft Advisory until noon CST Tuesday for GMZ532-534-536- 538-550-552-555-557-570-572-575-577. && $$ SHORT TERM...KLG LONG TERM....JFL AVIATION...RW MARINE...KLG
Area Forecast Discussion
National Weather Service Shreveport LA
945 PM CST Sun Jan 12 2025 ...New SHORT TERM... .SHORT TERM... (Tonight through Tuesday Night) Issued at 932 PM CST Sun Jan 12 2025 Air temps at this time are all over the place with the cold front moving through our I-20 Parishes at this time. Some clouds and rain showers continue ahead of the front with Peason Ridge and Alexandria both seeing rainfall last hour. We will keep the pops and weather going down there through about midnight. There is some patchy fog too in the SE winds, but the NW winds will take care of that issue in short order. We currently see mid 30s in our far north with mid 20s still on tap by daybreak. Shreveport and Monroe are both at 52 degrees and will end up in the mid to upper 30s with some 20-30 degree wind chills with the north wind at 10 mph at the bus stop. Dew points vary too, but with the 30s and 40s arriving, we see no reason to change any forecasted lows. The HRRR drives out the remaining QPF at 1am and skies will be clearing out for most of us with already lots of stars blending into the well lit sky as the moon will be full this time tomorrow. /24/ && .LONG TERM... (Tuesday through next Saturday) Issued at 158 PM CST Sun Jan 12 2025 After a chilly start to Tuesday, temperatures will rebound very well as highs will return to the upper 40s to mid 50s. This will be the start of what will be a warming trend heading later into the week, eventually reaching the 60s across the region by Friday. Speaking of Friday, thunderstorm potential will increase across the area as southwesterly flow returns to our area in addition to some shortwave troughs that will also move through. As a result, I have PoPs increasing early Friday morning and continuing through the day. As are most forecasts 5 or more days out, there remains some uncertainty in the model guidance to suggest that there will be any strong to severe thunderstorms, but it is at least enough to catch our eye. Speaking of catching our eyes, really long range models are indicating that towards the end of next week and into the following week we could see another shot of cold air to the region. I am sure we will all be seeing the post shortly, if not already, talking about this potential. Just keep in mind that there is so much variability in the models when it comes to looking out that far. For example, the GFS model currently indicates that temperatures will be similar to what we saw with our previous shot of cold air, however, the EURO during this time period has us returning to the ice age. Cast your votes now on what you see happening and we will go from there. /33/ && .AVIATION... (00Z TAFS) Issued at 723 PM CST Sun Jan 12 2025 For the 13/00z TAFS...VFR conditions at all sites, except KLFK/KMLU, where some low cigs continue to hang around in association with a sfc low along the TX/LA Gulf Coast. There has also been some rain with that low that could make it into KMLU over the next several hours. The remainder of the region has clearing skies from west to east in wake of a cool front. This front will continue to slowly push east through the region overnight, with mostly clear skies and NW winds in wake of it through the remainder of the period. /20/ && .SPOTTER INFORMATION STATEMENT... Issued at 214 AM CST Sat Jan 11 2025 Spotter activation is not expected at this time. 13 && .PRELIMINARY POINT TEMPS/POPS... SHV 36 50 30 53 / 10 0 0 0 MLU 39 49 28 52 / 20 0 0 0 DEQ 23 45 23 49 / 0 0 0 0 TXK 31 48 28 53 / 0 0 0 0 ELD 32 46 26 52 / 10 0 0 0 TYR 33 50 31 53 / 0 0 0 0 GGG 33 50 29 54 / 0 0 0 0 LFK 37 53 32 54 / 0 0 0 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ SHORT TERM...24 LONG TERM....33 AVIATION...20