Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/23/23


Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
925 PM CDT Wed Mar 22 2023 .UPDATE... Issued at 916 PM CDT Wed Mar 22 2023 Models continue to suggest areas of stratus expanding overnight, along with some potential for fog. Starting to see signs of this on satellite over the past hour or so. Will also be watching snow chances across the far southwest CWA, which the HRRR is still suggesting after 09Z may be the best bet for any light snow with minor accums down that way. May make some adjustments to POPs to hold off chances a bit longer and start them closer to 09Z/10Z. Otherwise, overnight lows are tricky and will largely depend on cloud cover. Could be several degrees off wherever clouds decide to hold in longer. && .SHORT TERM...(This Evening through Thursday Night) Issued at 235 PM CDT Wed Mar 22 2023 Though there are some radar returns across south central SD this afternoon, most of it seems to be from clouds rather than precip reaching the ground. Stratus across the north, under sfc high pressure, is slowly shifting/eroding this afternoon. There may be a few hours of scattered sunshine before stratus and/or fog develops tonight. The uncertainty regarding cloud cover has also led to lower confidence in overnight low temperatures. Cloud cover could keep lows in the teens to lower 20s. Any breaks in the clouds, however, would lead to a quick free fall given the very light winds and temps could fall into the single digits, especially across the north where there is fresh snow. Models continue the southward trend for any snow across south central SD. Accumulating snow of less than half an inch remains possible, mainly south of Pierre, late tonight into early Thursday morning. This is mostly due to the dry air entrainment from the sfc high and that the best shortwave forcing remains over NE and northern IA. Temperatures will remain well below average by 15 to 20 degrees on Thursday. Morning stratus/fog will keep any warming from occurring especially given the lack of mixing or thermal advection. With some mild waa slated for Thursday night, fog may be more likely. .LONG TERM...(Friday through Wednesday) Issued at 235 PM CDT Wed Mar 22 2023 Temperature trends through the extended period look to exhibit a roller coaster type pattern as a relatively dry trend sets up across the forecast area. Sfc high pressure will shift east of the region on Friday helping to draw in a bit of a warmer air mass into the area. A low level warm air advection pattern on Friday will lead to relatively mild temps. Warmest readings will be across our southwest zones where little to no snow cover means daytime readings around 50 degrees in some locales. The mid level flow pattern appears to take on more of that split flow`ish type look during the course of the weekend into next week. We may see a couple of weak waves traverse the region over the weekend. One may kick out a little light snow west river the first half of the weekend, but it appears now the system is minor in nature. A cold front is progged to push through sometime the latter half of the weekend with high pressure building in behind. A cooler air mass once again will set our temperatures back Sunday into Monday. Should see some modification by late in the period as this high shifts east of our area. && .AVIATION...(For the 00Z TAFS through 00Z Thursday Evening) Issued at 639 PM CDT Wed Mar 22 2023 Terminals KABR,KATY,KPIR,KMBG Still some MVFR CIGs affecting KATY this evening. Expect an increase in areal coverage of MVFR/IFR CIGs across the region as the night progresses. Also, cannot rule out some BR towards morning with MVFR/IFR VSBY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...TMT SHORT TERM...Wise LONG TERM...Vipond AVIATION...TMT
Area Forecast Discussion
National Weather Service Amarillo TX
138 PM CDT Wed Mar 22 2023 ...New SHORT TERM, LONG TERM... .SHORT TERM ... (This evening through Thursday night) Issued at 134 PM CDT Wed Mar 22 2023 Morning visible satellite showed clear skies in the western Oklahoma Panhandle and the northwest Texas Panhandle, and dense cirrus covering the rest of the area. The main concerns for today are wind in the northwest and fire weather potential for the entire area. A jet streak is moving over the Colorado Rockies this afternoon, intensifying lee cyclogenesis in eastern Colorado. 700mb winds will also strengthen, especially in the northwest. Forecast soundings are showing that the entire area should be able to mix into the 700mb to 600mb layer, so tapping into the 700mb winds shouldn`t be an issue. Furthermore, Guidance didn`t handle the clouds well in the northwest this morning, showing clouds when there weren`t any. Latest RAP and HRRR are showing the northwest could even mix into the 600mb to 550mb layer. This could be a bit overdone, nevertheless deep mixing provides increased concern for a higher wind scenario, with gusts up to or exceeding 60 mph for a 3 to 4 hour window in the afternoon. The stronger daytime heating scenario would also lower RH values, increasing fire weather concerns. Elsewhere in the Panhandles, the thick clouds should keep the winds and fire weather concerns down but non-negligible. A very weak Pacific front, that only provides about 5 deg C H85 cooling, will move through the area from the west this evening, and a cold front will move through a part of the northeastern Panhandles tomorrow morning before stalling out. The area should be in the right entrance region of the jet streak which will support weak low development in the vicinity in the afternoon. As the low moves east tomorrow evening, a stalled backdoor front in the northeast Panhandles will eventually be overcome by stronger front from the west that will push everything east. There will be a chance for showers primarily in the east near the backdoor front as S/WV passes through the area. Currently 40-50% probabilities for rain are shown in the east. Vanden Bosch/Gittinger && .LONG TERM ... (Friday through next Tuesday) Issued at 134 PM CDT Wed Mar 22 2023 Relatively uneventful weather - with a couple potential exceptions - and temperatures at least a bit below average for late March look to dominate the long term. Friday into Saturday, broad longwave trough slowly advances eastward over the Panhandles. A cold front, the first in a series of many, may sneak into the CWA Friday. A bit of low level moisture may pool behind this front, perhaps leading to a bit of light rain as the upper trough advances. That said, general trend in guidance has been for dry southwesterly flow at 850mb to keep favorable moisture out of all but our far north and northeast. Have therefore trended PoPs downward Friday and Friday night. By Saturday, lack of moisture at 700/850mb should lead to no chance for precipitation. For the remainder of the forecast, persistent west-southwesterly flow aloft should lead to generally little precipitation given 700/850mb winds will be oriented off the higher terrain and tracing back to the Mojave Desert virtually the entire time. Multiple disturbances ejecting over the central and northern Plains should lead to multiple weak cold fronts entering the forecast area, with the aforementioned issues with moisture precluding including more than a slight chance for precipitation. A model run of note is the current operational GFS which brings enough precip for more than a trace of snow to the northern Panhandles. Based on ensemble output and other operational guidance, have elected to leave this out entirely for now. But, given overall pattern, will have to continue to monitor this period and really the entire long term forecast as one cannot totally rule out a similar wave impacting the northern Panhandles at some point. Ferguson && .AVIATION... (18Z TAFS) Issued at 1224 PM CDT Wed Mar 22 2023 VFR conditions are expected through this period. Have only included blowing dust in the KDHT TAF as that`s where confidence is highest, but it will also be possible at KAMA and KDHT. Winds will gradually weaken after 8 PM. Vanden Bosch/Gittinger && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 45 72 37 62 / 0 10 30 10 Beaver OK 44 66 34 54 / 0 10 50 40 Boise City OK 40 63 32 55 / 0 10 20 20 Borger TX 46 74 37 62 / 0 10 30 20 Boys Ranch TX 43 69 35 62 / 0 10 20 10 Canyon TX 44 73 37 63 / 0 10 20 10 Clarendon TX 49 76 42 65 / 0 10 30 10 Dalhart TX 41 65 32 58 / 0 10 20 20 Guymon OK 42 66 33 55 / 0 10 40 30 Hereford TX 42 73 35 63 / 0 10 20 0 Lipscomb TX 46 71 36 59 / 0 10 40 30 Pampa TX 47 73 38 61 / 0 10 40 20 Shamrock TX 50 76 42 65 / 0 10 40 20 Wellington TX 50 78 44 67 / 0 10 40 10 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...Red Flag Warning until 8 PM CDT this evening for TXZ001>020-317. High Wind Warning until 8 PM CDT this evening for TXZ001-006. Wind Advisory until 8 PM CDT this evening for TXZ002-003-007-011. OK...Red Flag Warning until 8 PM CDT this evening for OKZ001>003. High Wind Warning until 8 PM CDT this evening for OKZ001. Wind Advisory until 8 PM CDT this evening for OKZ002. && $$ SHORT TERM...52 LONG TERM....77 AVIATION...52
Area Forecast Discussion
National Weather Service Billings MT
905 PM MDT Wed Mar 22 2023 .UPDATE... Precipitation associated with shortwave moving across WY is almost entirely south of our cwa this evening. There could be a few light snow showers over our southern mountains, while skies are mostly clear elsewhere on the MT side. Have adjusted pop/wx/sky grids to show the more southerly location of light snow and clouds. There is a risk of fog in our east tonight, and in fact, Baker is already reporting a visibility of 6-7 miles. HRRR is suggestive of localized fog from Miles City to Alzada eastward and northward later tonight, but it appears we will see some fog impacts before then. Much greater fog coverage will be across the high-line, but nonetheless have added patchy fog to our east tonight thru 15z Thursday. Low temps tonight will reach the teens to lower 20s most places...and perhaps single digits at Baker. JKL && .DISCUSSION... Tonight through Thursday night... Large open trough over Nevada/Calif ejecting some energy through central Rockies/Wyoming. Push north has been weak and only minor affects for the southern border of our CWA expected through evening. Some light snow in the Big Horns and nearby foothills mainly south of Sheridan. The shortwave energy tracks into South Dakota this evening and may see a glancing blow to the SE corner of MT (Alzada), but otherwise we should be mostly dry overnight with lows ranging from single digits and teens in the east to mainly 20s elsewhere. Thursday should be a relatively mild day as high pressure aloft dominates our overall pattern. Highs will be in the 40s to lower 50s. A weather system pushing into the Pacific NW will back our mid level winds to the SW during the day and may result in scattered snow showers over our western mountains (Absaroka/Beartooths) into Thursday night. Lows Thursday night will be in the teens east to near 30 west. Hydrology...Its Ice Jam season! Ongoing ice jams continue along the Powder River near Broadus where fields have been flooded. Ice jamming is being monitored near Miles City in Custer County as well. Those living near rivers or streams should pay close attention to the state of the ice over the next week or two. Move livestock and equipment to safe areas. Please check our webpage at weather.gov/billings for any flood watches or warnings, the latest Hydrologic Outlook, and additional information about ice jams. BT Friday through Wednesday... Snow inbound to end the work and start the weekend, in what continues to be a never-ending period of off and on snow for southern MT and northern WY. SYNOPSIS | A broad upper trough is in place for much of the western CONUS for the second half of this week. The play maker is a wave and lowering heights coming down the coastline and crossing the Pacific Northwest, in what looks to develop into an upper low. Current placement of a cutoff- upper low from the main wave and a surge of moisture looks to occur from northwest WY through central, WY, which is a prime placement to bring heavy snow potential to our foothill locations, and northwest to northeast slopes. Ample upslope, upper jet divergence, and bands of mid- level frontogenesis are all in play for this event to bring snow potential to the area. CONFIDENCE | There is a high chance for impactful snow amounts to occur in the Beartooth and Bighorn foothills, essentially at and south of I-90 from Livingston through Sheridan, WY. Current NBM guidance gives Livingston a 55% chance to see over 2" of snow, and Sheridan an 82% chance, with most ensemble means matching up with this. However, higher-resolution deterministic models show- case a higher potential for heavy snow to occur. The GEFS and GFS also contain a band a 700mb frontogenesis that wants to set-up in southeast MT and provide ascent to bring them a shot of snow. While the chance of that occurring is small (as it`s not shown in other ensembles yet), it should not be ruled out. IMPACTS | There is a high chance for the Friday evening and Saturday morning commutes to see winter driving conditions. There is even a 20% chance for precip to fall as rain before switching to snow, which could result in ice surfaces then covered by snow. I-90 is the main road with concerns, but all highs alongside and south of it will be impacted as well. There is also a small chance for US-212 to see snow and slick roads if that frontogenesis band pans out. BEYOND SATURDAY | Not much else to highlight going into early next week. Temperatures will stay below 10-15 degrees below normal, and there is a small chance for off and on light snow. So no drastic warm-up on the horizon. Vertz && .AVIATION... Overall VFR conditions will prevail. However, there could be some MVFR to IFR conditions could develop around KBHK and KMLS as there is a chance for some patchy fog to develop. This will mostly be limited to the river valleys. Otherwise, expect some mountain obscurations and some snow showers, mainly near the Bighorn Mountains. Reimer && .PRELIMINARY POINT TEMP/POPS... Thu Fri Sat Sun Mon Tue Wed ----------------------------------------------------------- BIL 023/052 030/049 029/036 026/038 020/035 019/042 023/042 00/U 05/R 54/S 44/S 31/E 11/B 22/S LVM 017/048 028/040 023/034 021/034 019/036 020/041 021/042 00/B 27/S 54/S 34/S 21/B 12/S 22/S HDN 017/052 024/049 025/037 022/039 018/037 014/044 018/045 00/U 04/R 64/S 44/S 31/E 11/B 22/S MLS 015/047 025/049 025/036 024/037 020/033 020/043 021/042 00/U 01/B 22/S 12/S 11/E 00/B 11/B 4BQ 018/046 025/050 027/036 024/037 023/035 019/045 023/044 00/B 01/B 53/S 22/S 21/E 00/B 12/S BHK 009/039 019/044 020/031 016/033 013/029 013/038 018/039 00/B 00/U 22/S 11/E 11/E 00/B 11/B SHR 014/044 018/042 020/031 015/032 013/031 011/038 015/039 21/B 04/S 86/S 44/S 21/B 01/B 23/S && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings
Area Forecast Discussion
National Weather Service Quad Cities IA IL
650 PM CDT Wed Mar 22 2023 ...AVIATION UPDATE... .SYNOPSIS... Issued at 226 PM CDT Wed Mar 22 2023 Clouds under a rather strong inversion per 12z KDVN sounding kept temperatures a few degrees warmer today. Temperatures at 2 pm were in the upper 40s for most locations. Latest GOES visible satellite shows some thinning of the low stratus, as well as some convective clouds over north central IL. Radar mosaics show some scattered showers tracking east over northern IL. Lastly, 18z MSAS analysis and surface observations show warm front stretching from near Kansas City through northern MO, to near Springfield IL. && .SHORT TERM...(This evening through Thursday) Issued at 226 PM CDT Wed Mar 22 2023 Forecast focus is on storm chances tonight. Scattered showers will be possible this afternoon and evening across southeast IA, northeast MO, and west central IL. Not anticipating much QPF with this. Attention then turns to tonight where another 40kt LLJ, WAA, and convergence along an elevated boundary brings showers and thunderstorms to portions of the area primarily after midnight. The latest RAP shows a strong 850mb theta-e gradient laying out from northwest MO into northwest IL with forecast soundings continuing to show MUCAPES over 1000 J/kg and steep mid level lapse rates. The 12z HREF and CAMs show scattered storms capable of producing small hail and perhaps a few close to quarter size, focused south of I-80 and agree that this is the area most at risk. A Marginal risk (level 1 of 5) for severe storms was maintained today by the Storm Prediction Center for a few isolated severe storms. This activity will quickly shift east out of the area before sunrise Thursday, as a cold front moves through. Rain amounts around an inch will be possible in areas that see repeated storms. Further north, more stratiform rain will be possible, with most areas receiving less than a quarter of an inch. In addition, a rain-snow mix is also possible across areas north of highway 20 tonight. No accumulation is expected. Overnight lows, will be in the low 30s north, to the lower 40s in west central IL. .LONG TERM...(Thursday night through Wednesday) Issued at 226 PM CDT Wed Mar 22 2023 Key Messages: 1. Active pattern continues into the weekend, with increasing chances of rain changing to a heavy wet snow late Friday night into Saturday. Some light accumulations may be possible north of highway 30. 2. Additional chances of precipitation will be possible Sunday night and late next week, with near normal temperatures. Thursday night-Saturday...an upper level trough will track east into the Central Plains, through the mid Mississippi valley, and into the Great Lakes region. Latest 12z models have continued to shift slightly to the west with their surface low tracks resulting in greater chances of a deformation band of precipitation to affect generally the eastern half of the CWA. Thermal profiles and strong dynamic cooling suggest a changeover to snow is possible late Thursday night into Friday. Latest NBM probabilities of 1" of snow are highest (20-40%) along and north of highway 30, with higher probs in southern WI. With marginal surface/road temps and the time of year, it will take very strong lift and heavy precipitation falling to overwhelm the warm ground to get any slushy accumulations. This will be possible with this system. Storm track, timing, and strength will be key to watch in later forecasts as this will dictate areas that may have impact. Gusty north winds will also accompany this storm as it deepens into the Great Lakes, with occasional gusts between 30-40 mph. Still a lot of uncertainty on the details and we`ll have to monitor this system closely for the potential for a band of heavy wet snow somewhere in the Mid Mississippi Valley. Saturday night On...another shortwave will track across the Plains Sunday night into Monday bringing more precip chances to the area and yes even some more snow chances. Confidence remains low on any impacts, with large model discrepancies in timing and strength of system. Highs in the 40s and lows in the upper 20s and low 30s are forecast. A stronger wave will move through just beyond the 7 day forecast, with warmer temps possible. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 635 PM CDT Wed Mar 22 2023 MVFR to IFR cigs will remain through much of the night, with some localized areas of LIFR cigs, especially at BRL. Rain and thunderstorms will work their way into the area around 03z and will persist on and off through the night. Some storms may have hail, with a slight chance for some to see large hail. The stronger showers and storms may lead to some brief reductions in visibility. Around 10-12z, we will start to see these showers and storms move out of the area, leaving us cloudy through the remainder of the day. Cigs will slowly improve after 18z Thursday. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Gross SHORT TERM...Gross LONG TERM...Gross AVIATION...Gunkel
Area Forecast Discussion
National Weather Service Grand Forks ND
952 PM CDT Wed Mar 22 2023 .UPDATE... Issued at 952 PM CDT Wed Mar 22 2023 Stratus clouds continue to move south and eastward, leaving skies across the CWA mostly clear. Several spots have already dropped into the low single digits, so adjusted temps down just a bit. There is some fog starting to develop over the Harvey area, but from web cams so far it seems pretty patchy. Still a lot of variation in exactly how fog and stratus behave overnight, but think there will be at least some return of clouds back into some portions of our forecast area, so did not drop temps quite as low as some of the models such as the HRRR and RAP show. UPDATE Issued at 706 PM CDT Wed Mar 22 2023 Adjusted sky cover grids, as the western edge of the stratus continues to dissipate and no models are handling it very well. Will continue to keep an eye on clearing trends as the evening goes on, there is a lot of uncertainty if stratus will fill back in and/or we get fog, or if we will remain clear throughout the night. && .SHORT TERM...(This evening through Thursday night) Issued at 256 PM CDT Wed Mar 22 2023 Key Messages - There could be some fog tonight, depending on cloud trends and wind - Quiet weather looks to prevail with below normal temperatures Starting with current conditions, the surface low has pushed into southern Ontario, with high pressure over the central Dakotas. Between the 2, there was still a decent surface pressure gradient, resulting in 10 to 20 mph northwest winds. This was just enough to cause a little drifting snow across roads, which could result in a few slippery spots going into tonight. These winds are expected to become light by mid evening. Cloud cover could be a little tricky tonight. It has been clearing across eastern North Dakota, while it has been taking longer east of the Red River. If these clearing trends continue and hold overnight, there could be some patchy fog. However, confidence in this potential remains low, so will leave out for now. If it remains clear, temperatures could also bottom out more than currently anticipated (with the fresh snow). The latest HRRR shows some below zero readings possible. Otherwise the rest of the period looks quiet, with highs remaining below normal. .LONG TERM...(Friday through Wednesday) Issued at 256 PM CDT Wed Mar 22 2023 The long term period is characterized by quiet weather and below average temperatures for eastern North Dakota and western Minnesota. Temperatures according to the EFI are well below normal in both Max and Min temperatures. Highs will remain in the 20s and 30s, possibly dipping into the upper teens over the weekend. There is a low chance of precipitation coming through the area at any point in the long term according to guidance, but the upper level zonal flow does support the possibility for fast moving systems. If we do get any disturbances, they most likely will be transient and only produce light precipitation across the area. There is significant uncertainty in the ensembles regarding the possibility of UL waves into next week. The next chance for precipitation looks to be on Wednesday, but it looks to be slight right now. We`ll continue to monitor as we get closer in time. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 706 PM CDT Wed Mar 22 2023 Stratus has dissipated at all sites except KBJI, and that one should see a return to VFR from MVFR in a few hours. There is a lot of uncertainty if stratus will fill back in, if we will get fog development, or if skies will remain clear. None of the models are handling current conditions very well and trust in their output is low. There is some consensus with the short range guidance on bringing some MVFR then IFR stratus back in the KDVL area, so included that in the TAFs. Kept the rest of the airports VFR throughout the night for now. Winds will become light and variable, so patchy fog is not out of the question, but think higher chances will be to our south and west directly under the surface high. All sites should return to VFR by tomorrow morning, with winds eventually picking up out of the south at around 10 kts. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...JR SHORT TERM...Godon LONG TERM...AK AVIATION...JR
Area Forecast Discussion
National Weather Service Lincoln IL
829 PM CDT Wed Mar 22 2023 .SYNOPSIS... Issued at 640 PM CDT Wed Mar 22 2023 Scattered showers and thunderstorms will develop across central Illinois late this evening into the overnight hours. While widespread severe weather is not expected, a few of the cells north of the I-70 corridor could produce hail. Low temperatures will range from the lower 40s west of the Illinois River...to the middle 50s south of I-72. && .UPDATE... Issued at 829 PM CDT Wed Mar 22 2023 0115z/815pm regional radar mosaic is showing scattered showers and thunderstorms develeloping across northern Missouri and far southern Iowa on the nose of a developing nocturnal low-level jet. This activity is expected to grow in converage and track eastward across the northern half of the KILX CWA over the next several hours. While the boundary layer remains stable, latest SPC mesoanalysis shows MUCAPEs of 500-1000J/kg poised upstream across northern Missouri. This elevated instability will feed the increasing convection across the area late this evening, with some of the storms potentially producing hail as they take advantage of steep mid-level lapse rates already seen on the 00z KILX upper air sounding. HRRR has been consistently showing the showers/storms blossoming along a Quincy to Bloomington corridor between 02z/9pm and 03z/10pm...with the activity quickly pushing E/NE into Indiana overnight. While scattered showers will persist through the entire night into Thursday morning as a cold front slowly settles southward through the region, think the greatest probability of hail will be between 03z/10pm and 08z/2am. && .SHORT TERM...(This evening through Thursday) ISSUED AT 323 PM CDT Wed Mar 22 2023 This afternoon`s surface analysis reveals a southeasterly pressure gradient across the ILX forecast area, yielding southerly flow. A surface trough currently located across north central MO into northern portions of the ILX forecast area will remain nearly stationary for the next several hours, with a southward advancing cold front dislodging the surface trough sometime after midnight. Overnight, the airmass north of the front will feature a stable near-surface layer, but with MUCAPE from 100-500 J/kg and plentiful southwesterly shear roughly parallel to the boundary we anticipate a threat of thunderstorms in a persistent warm advection regime owing to the overnight intensification of the low level jet. South of the front, the near surface air will be much warmer and more humid, but forecast soundings still feature a near isothermal layer at the surface. As such, any convection near/south of the boundary is expected to remain elevated as well, with isolated large hail the primary threat. However, we`ll need to monitor for any storms which could manage to become rooted in a warm/humid boundary layer for potential severe wind gusts with such strong shear. Coverage of convection/showers is forecast to decrease by late morning or so on Thursday as the low level jet weakens. Following that point, precipitation should largely hold off until late afternoon/early evening with the cold front continuing to move southward during the day, reaching a position south of I-70 by late afternoon. .LONG TERM...(Thursday night through Wednesday) ISSUED AT 323 PM CDT Wed Mar 22 2023 The main notable concern in the long term is the threat of heavy rainfall mainly south of I-70 in the Thursday night - Friday night time frame. With a persistent southwesterly low level jet Thursday night advecting moisture over the southward-moving cold frontal boundary, lift from warm advection aloft will lead to several hours of rain. As flow aloft will be nearly parallel to the boundary, some could see substantial rainfall totals, especially south of I-70. The HREF LPMM QPF has 1" - 1.75" totals south of I-70 by 7 am Friday, with rain perhaps extending a bit later into the morning. 90th percentile HREF plots show that 3.5" amounts are a reasonable upper bound for this first round. CAMs show a couple hundred J/kg of MUCAPE near the cold frontal boundary in the evening on Thursday south of I-70, so we`ll need to monitor for an elevated hail threat as well. The next notable round of rainfall comes on Friday afternoon/evening as the main trough heads eastward, along with its accompanying surface low. Ensemble cluster analysis reveals some differences regarding this round, with around 75% of ensemble members in clusters with a shallower and faster-moving trough, and less precipitation. These clusters average a little over an inch with this second wave. 25% of members are in a deeper, slower-moving cluster averaging around 1.75-2" with the second round. A Flood Watch has been issued for our counties south of I-70 from Thursday evening through late Friday night to account for the threat of excessive runoff, river rises, and flooding of low water crossings. Expect increased winds on Saturday associated with the eastward moving surface low, with some gusts approaching 40 mph east of I-55. Additional light rain is forecast with an eastward moving trough on Sunday, with a couple of dry days with near normal high temperatures anticipated afterward. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 652 PM CDT Wed Mar 22 2023 2345z/645pm radar imagery is beginning to show scattered shower development from KUIN northeastward to KBMI. Showers and a few embedded thunderstorms will become more widespread within this corridor over the next few hours as an upper disturbance approaches from the west. Based on radar trends and latest HRRR/RAP forecasts, have added predominant showers with VCTS at all terminals between 03z and 04z. It appears the main area of showers/storms will shift eastward into Indiana overnight, so have dropped back to just VCSH after 07z-08z. Ceilings will remain IFR through the entire 00z TAF period, with perhaps some improvement to MVFR at KPIA late in the period. Winds will initially be S/SE, then will shift to N/NE late tonight into Thursday morning as a cold front sags through the area. Models continue to depict a strong low-level jet developing in advance of the front tonight, so have included low-level wind shear at the I-72 terminals accordingly. && .ILX WATCHES/WARNINGS/ADVISORIES... Flood Watch from Thursday evening through late Friday night for ILZ062-063-066>068-071>073. && $$ UPDATE...Barnes SYNOPSIS...Barnes SHORT TERM...AAT LONG TERM...AAT AVIATION...Barnes
Area Forecast Discussion
National Weather Service North Platte NE
1021 PM CDT Wed Mar 22 2023 .SYNOPSIS... Issued at 403 PM CDT Wed Mar 22 2023 Key Messages: - Snow and a wintry mix are expected across the Sandhills this evening through tomorrow morning. A Winter Weather Advisory remains in effect for northern Nebraska due to light snow accumulations. - A series of other systems brings additional precipitation chances Friday through Monday. - Temperatures through the forecast period will be generally below normal. Synopsis: Nebraska lies in southwest flow aloft today in a split pattern as the southern jet intensifies over the Missouri Valley while a trough digs into the Upper Mississippi Valley. A rather stout mid-level wave is ejecting off the northern Rockies and providing increased frontogenesis over the Sandhills. Toward the surface, the state is squeezed between a northern Plains high and a central/southern Plains developing low. Northerly low level winds and cloud cover are keeping afternoon temps (as of 20z) in the 30s across the northern Sandhills, while east/southeast winds and filtered sunshine pushed southwest Nebraska to around 50F. && .UPDATE... Issued at 1015 PM CDT Wed Mar 22 2023 Just sent out an update and added Thomas, Hooker, Grant, Garden and Arthur counties to the winter weather advisory. Radar returns indicate a nice band of moderate to heavy snow extending from Garden county, east northeast into Arthur, Hooker and Thomas counties. Thedford recently fell off to a half a mile of visibility with moderate snow. Highway cameras also have indicated some brief periods of moderate to heavy snow. I also did increase snow accumulations somewhat along this corridor. This is supported by the latest HRRR soln which generates QPF`s around a quarter inch within this band. Even with an 8 to 1 or 10 to 1 ratio, we could see a quick 2+ inches of snow within this band. && .SHORT TERM...(This evening through Thursday night) Issued at 403 PM CDT Wed Mar 22 2023 This evening and tonight... The large upper ridge centered over the Southeast US pulls east a bit, placing western Nebraska more in the influence of the western waves. The H3 jet remarkably strengthens over the forecast area as shown by a streak increasing from 110 kts this evening to 150 kts by daybreak. The H5-7 forcing maxes out around 06z and pushes east toward dawn. Isentropic analysis indicates broad upglide over the entire CWA (mainly 285-290K), while the easterly low level flow pulls additional moisture into the area. The extra moisture combined with forcing should result in a band of precipitation across the central Sandhills into north central Neb and perhaps more scattered activity to the south. Adjusted PoP based on the newer HREF, NAMnest, and HRRR suites. P-type is a little tricky with this system due to the sharp temperature gradient and possibly some convective features sneaking into central Neb. Along and north of the main band, the colder air mass should keep precip as mostly snow. Near and south, initially warm surface temps and later an elevated warm nose, introduces the potential for sleet and freezing rain. Some solutions also hint at marginal instability in central Nebraska. SLR`s range from 3-7:1 south of Hwy 92 to 7-10:1 around the Hwy 2 corridor to 10-13:1 across the north. The main band will also be a quick-hitter with the bulk of the accumulation occurring in about six hours, centered around 06z. With all that in mind, snow amounts should generally line up in the 1-3" range in the existing Advisory area (northern tier of counties). Can`t rule out higher amounts around O`Neill and points east. As for icing, potential exists for a light glaze in Custer County and adjacent areas. Did not expand the advisory farther south due to lower confidence in coverage/potential of precip with the more scattered nature. Min temps should range from the lower 20s in the north to mid 20s in the southwest. Thursday and Thu night... Other than a few remnant snow showers across far northern Neb during the morning from leftover mid-level forcing, most of the CWA will have a lull in the activity during the day. Temperatures will be fairly similar to today`s as the surface high settles more onto the northern Plains. Western Nebraska will be placed more in the southerly return flow and drier air, while north central will stay chilly in the northerly H85 flow and extended cloud cover. Forecast values range from the mid 30s to the lower 50s. Later in the evening, yet another low spins up on the Colorado Plains. Low level flow switches to easterly/upslope, and an accompanying weak H7 low provides increased forcing in the mid levels. Expanded schc-chc PoP across southwest Neb to account for scattered rain or rain/snow showers. .LONG TERM...(Friday through Wednesday) Issued at 403 PM CDT Wed Mar 22 2023 An active wave pattern will keep conditions unsettled across the central Plains to round out this week and to start next week. Several mid/upper level troughs and a couple surface fronts with all varying intensity will cross Nebraska. Kept nearly consistent low end PoP from Friday to Monday, although in all likelihood, any precip will be periodic. Temperatures will also remain near or below normal during this period, with the mildest conditions on Friday (highs near 50F) and coolest Sunday and Monday (highs in the 30s north and 40s south). && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 638 PM CDT Wed Mar 22 2023 The main aviation concern will be the arrival of precipitation across the region by late evening. Snow will be primarily across the north impacting KVTN while rain will impact KLBF. Both terminals could see reductions in visibility due to falling snow and rain. Conditions improve Thursday morning as precipitation comes to an end, however, ceilings will remain below 3000 feet through the rest of Thursday afternoon. && .LBF WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 10 AM CDT /9 AM MDT/ Thursday for NEZ004>010-022>025-035-094. && $$ UPDATE...Buttler SYNOPSIS...Snively SHORT TERM...Snively LONG TERM...Snively AVIATION...Kulik
Area Forecast Discussion
National Weather Service Melbourne FL
921 PM EDT Wed Mar 22 2023 .DISCUSSION... Current-Thursday...Surface high pressure continues to push seaward from the mid Atlc coast with associated ridge axis extending back toward central/north-central FL. Diurnal clouds have mostly dissipated or moved into WCFL this evening. Expect MClear conditions overnight and MSunny skies on Thu. Low confidence for fog development, but local HRRR does try to develop some patchy fog north/west of I-4 toward sunrise Thu morning. Will closely monitor, though have not added to grids/zones. ESE/SE winds will diminish after sunset this evening and pick back up for Thu with similar speeds as today and directional component. Overnight mins in the M- U50s interior and L60s along the coast, except for some M60s along the immediate St. Lucie/Martin coasts. Highs on Thu U70s to near 80F along the coast and L-M80s inland; possibly U80s well into the interior and along the Kissimmee River. && .MARINE...Overnight-Thu...Stubborn and persistent northeast long period swell continues to keep wave heights higher than model guidance. Have kept Cautionary Statements ongoing across offshore Brevard and Treasure Coast waters as seas build to 6 ft here and 3-5 ft elsewhere. Seas on Thu forecast 3-5 ft areawide (highest Gulf Stream). ESE/SE winds around 15 kts offshore and 10-12 kts near shore. Conditions mostly dry. && .AVIATION...Generally VFR thru the period. Local HRRR trying to suggest some patchy fog north/west of I-4 toward sunrise. Confidence low here. ESE/SE winds will fall to light again this evening. Expect similar directional component for winds on Thu with speeds 6-10 kts interior/Volusia coast and 10-15 kts along the Space/Treasure coasts. MClear to PCloudy skies with dry conditions. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Sedlock/Leahy
Area Forecast Discussion
National Weather Service Tallahassee FL
1015 PM EDT Wed Mar 22 2023 ...New UPDATE... .UPDATE... Issued at 1011 PM EDT Wed Mar 22 2023 The forecast remains largely on track. The last several HRRR cycles have been very consistent with the placement of dense fog across the Florida Panhandle and into Southeast Alabama. The overall pattern is supportive of widespread dense fog in this area as moisture return has increased throughout the day. Even though satellite imagery does not yet show much fog development, this should rapidly change in the next couple of hours. As a result, a dense fog advisory has been issued for areas most likely to experience dense fog overnight. && .SYNOPSIS... Issued at 353 PM EDT Wed Mar 22 2023 Strong high pressure will persist through Friday, supporting rain-free weather and well above normal temperatures. A cold front will approach southeast Alabama and west-central Georgia on Saturday, but then it will weaken and get hung up before entering Florida, lingering over the Southeast States until Monday. A stronger front will push all the way through the tri-state region around Tuesday or Wednesday of next week. && .NEAR TERM... (Through Thursday) Issued at 353 PM EDT Wed Mar 22 2023 The main story tonight will be the fog potential as warmer, more moisture-rich air moves into the area. It looks like the best shot at fog will generally be from Dothan to Tallahassee southwestward. Some of this fog could be locally dense. Remember, if you encounter fog while driving: slow down, use low-beam headlights, and increase your following distance from other vehicles. Lows will be in the 50s. The fog and low clouds will gradually dissipate through the morning, leaving us with mainly sunny skies in the afternoon. Temperatures will respond to the sunshine and the strong upper-level ridging we`ll have on top of us. Highs should reach the middle 80s along and east of the Flint and Apalachicola Rivers with upper 70s to lower 80s west. The caveat to this forecast is if fog and/or low stratus hang around for longer in the morning (similar to today in southeast Alabama), our highs could be a couple degrees too warm, especially in our western areas. && .SHORT TERM... (Thursday night through Monday) Issued at 353 PM EDT Wed Mar 22 2023 A strong 500 mb high will move east across the FL Peninsula on Thu night, then move out east across the Bahamas on Friday and Friday night. Upper heights over the forecast area will start to fall on Friday and Friday night, as a potent 500 mb shortwave move from the Southern Plains on Friday to the upper Great Lakes on Saturday. So warm and dry conditions will continue through Friday under high pressure aloft. A cold front will push into central Alabama... possibly into southeast Alabama... on Saturday, before weakening and losing definition while getting hung up over Alabama and Georgia on Sunday and Monday. On Saturday as flow aloft peaks and briefly takes on a slight cyclonic curvature, moderate instability will develop on Saturday afternoon. If the front gets close enough, or perhaps an outflow boundary from earlier convection can drift south, there could be enough focus for thunderstorm development. Convective parameters would then favor strong storms, with isolated severe possible. As the washed out and ill-defined front lingers over Alabama and Georgia on Sunday and Monday, a chance of showers and thunderstorms will also stick around, especially during the daytime hours. && .LONG TERM... (Monday night through Wednesday) Issued at 353 PM EDT Wed Mar 22 2023 A more solid cold front is likely to pass across the forecast area around Tuesday or Wednesday, as an upper trough ejects out of the Rockies and moves east. There are timing differences, with solutions on frontal timing ranging from Tuesday morning to early Wednesday. Strong thunderstorms could precede the front. The timing differences make Tuesday as a day of greater forecast uncertainty, depending on how quickly the front moves through. Regarding thunder with the Tuesday-ish frontal passage, it is notable that mid-level lapse rates steepen nicely. This makes deep convection possible, with a some early signals of a conditional hail threat in what could be a fast-moving line of storms. && .AVIATION... (00Z TAFS) Issued at 731 PM EDT Wed Mar 22 2023 Fog and low stratus will settle into the region around 05z tonight affecting ECP, DHN, ABY, and TLH through about mid morning. IFR cigs and LIFR vsbys are expected overnight, particularly for ECP and DHN that could have very low visibilities less than 1/4 mile. Winds will be calm and will later pick up during the afternoon as southerly to southwesterly at about 5-10 kts. When the fog and low stratus clears by mid-late morning into early afternoon, the skies will be clear and VFR cigs will be expected through the rest of the TAF period. && .MARINE... Issued at 353 PM EDT Wed Mar 22 2023 Light to gentle southerly breezes of 6-10 knots prevail this afternoon at Buoys 39 and 36, with wave heights running 2-3 feet from the east. Seas will decrease a bit more this evening, then remain under 3 feet until late Thursday night. From CWF synopsis...High pressure east of Florida will maintain gentle to occasionally moderate southeast breezes through Thursday night. Southerly breezes will freshen on Friday night and Saturday, as a cold front dissipates over the Southeast States. We will then return to a pattern of high pressure east of Florida, with gentle to moderate southerly breezes over the northeast Gulf. && .FIRE WEATHER... Issued at 353 PM EDT Wed Mar 22 2023 High dispersions are expected across southwest Georgia Thursday afternoon as transport winds increase to around 15 mph out of the southwest and mixing heights rise to 4,500-5,000 feet. Elsewhere, good dispersions are expected with slightly lower mixing heights and south to southwest transport winds around 10-15 mph. Relative humidity will remain above critical levels, dropping into the upper 30s to lower 40s inland, and upper 40s to the 50s along the coast. Transport winds increase a bit on Friday (15-20 mph) and further on Saturday (20-25 mph) ahead of an approaching cold front. This will lead to high dispersions in the Alabama and Georgia zones both days. Showers and thunderstorms will be possible Saturday, with the highest chances over the western parts of the forecast area. && .HYDROLOGY... Issued at 353 PM EDT Wed Mar 22 2023 No flooding is expected for the next 7 days. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur (while following all local, state, and CDC guidelines) by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 54 83 58 83 / 0 0 0 0 Panama City 59 77 63 77 / 0 0 10 0 Dothan 54 82 58 83 / 0 0 0 0 Albany 54 85 56 86 / 0 0 0 0 Valdosta 57 86 57 86 / 0 0 0 0 Cross City 56 85 56 83 / 0 0 0 0 Apalachicola 60 75 63 74 / 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...Dense Fog Advisory from 3 AM EDT /2 AM CDT/ to 10 AM EDT /9 AM CDT/ Thursday for FLZ007>015-026-108-112-114-115. GA...None. AL...Dense Fog Advisory from 2 AM to 9 AM CDT Thursday for ALZ065>069. GM...None. && $$ NEAR TERM...Godsey SHORT TERM...Haner LONG TERM....Haner AVIATION...Montgomery MARINE...Haner FIRE WEATHER...Young HYDROLOGY...Haner
Area Forecast Discussion
National Weather Service Tulsa OK
937 PM CDT Wed Mar 22 2023 ...New SHORT TERM... .SHORT TERM... (The rest of tonight) Issued at 934 PM CDT Wed Mar 22 2023 Mild night underway with overnight low temps near seasonal high temperature values. Forecast is on track and update will incorporate observed trends. Latest guidance continues to support widespread showers and storms developing tomorrow afternoon with locally heavy rains tomorrow night into Friday. && .LONG TERM... (Tomorrow through Wednesday) Issued at 222 PM CDT Wed Mar 22 2023 The main concern today will be severe weather and heavy rain/flood potential Thursday afternoon thru Friday. A cold front will push into NE OK tomorrow morning and will gradually stall near the I-44 corridor Thursday afternoon ahead of an approaching southern stream wave. Showers and storms will increase in coverage Thursday afternoon near the front from central into northeast Oklahoma. These initial storms will have 1k-2k j/kg of CAPE and 70kts of 500mb flow to work with, and as such the 06Z and 12Z runs of the HRRR and the 00Z and 12Z HREF both show a corridor of UH tracks along or just south of I-44 during the afternoon. Large hail, possibly golf ball or larger, and some damaging wind will be the main threats. Weaker low-level flow/shear, from the surface to 850mb, will limit the tornado threat with this event. The severe threat is expected to wane into the evening hours as storms spread east. However, storm motions nearly parallel to the forcing boundary may lead to training storms, along with the potential for multiple rounds of storms as the boundary sinks slowly south and elevated storms develop north of it over the same areas. The latest data suggests the potential for localized 3 to 5 inch amounts across NE OK into NW AR, increasing the potential for flash flooding. A flood watch has been issued to cover this threat beginning Thursday afternoon. The ejection of the southern stream wave has been trending slower in the recent data, suggesting that the heavy rain threat will linger in the eastern portions of the forecast area well into Friday. For this reason, the flood watch will be in effect thru the day on Friday. Another round of storms is expected to develop near the advancing frontal low and Pacific front late Thursday night into Friday morning to our west and is expected to advance east into southeast Oklahoma and west-central Arkansas Friday morning. These storms could pose a severe wind threat before shifting east of the area by afternoon. Another wave will slide across the central Plains on Sunday, but the latest data has trended drier and thus the low PoPs in the going forecast were left unchanged. The weather heading into the next work week looks largely tranquil. Lacy && .AVIATION... (00Z TAFS) Issued at 651 PM CDT Wed Mar 22 2023 VFR conditions prevail across eastern Oklahoma and western Arkansas this evening. Flying conditions are expected to worsen later tonight and especially on Thursday as moisture surges into the region in advance of a cold front. Thunderstorms will begin to impact area sites Thursday afternoon with poor flying conditions in and around thunderstorm areas. && .PRELIMINARY POINT TEMPS/POPS... TUL 66 74 49 60 / 0 90 90 70 FSM 63 77 62 71 / 0 40 90 90 MLC 65 75 57 69 / 0 50 100 80 BVO 62 73 44 58 / 10 50 80 60 FYV 63 70 55 66 / 0 90 100 90 BYV 64 72 53 64 / 0 80 100 90 MKO 65 74 54 65 / 10 80 100 80 MIO 66 70 46 59 / 10 80 90 80 F10 65 73 51 65 / 0 90 90 70 HHW 65 78 64 74 / 10 30 80 80 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Flood Watch from Thursday afternoon through Friday evening for OKZ057-058-060>072. AR...Flood Watch from Thursday afternoon through Friday evening for ARZ001-002-010-011-019-020. && $$ SHORT TERM...07 LONG TERM....30 AVIATION...10