Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/21/23


Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
913 PM CDT Mon Mar 20 2023 .UPDATE... Issued at 901 PM CDT Mon Mar 20 2023 Not many changes to the overnight period forecast. Mid and high level clouds are increasing from west to east, so generally shouldn`t see too much more of a drop in temps for the rest of the night. That said, some locations have cooled quickly this evening prior to the onset of thicker cloud cover, so made a few adjustments to lows. Otherwise, lead impulse tonight still looks to bring some snow chances to north central SD between 06Z and 12Z, before the main brunt of snowfall later in the morning/afternoon Tuesday. RAP soundings show saturation in Lemmon around 08Z. No changes to POPs at this time. && .SHORT TERM...(This Evening through Tuesday Night) Issued at 400 PM CDT Mon Mar 20 2023 The main focus in this period will revolve around the incoming storm system for Tuesday into Tuesday night. In the meantime, quiet weather conditions can be expected this evening into the early overnight. The sfc ridge will drift eastward and away from our forecast area this evening. Clear to partly cloudy skies will give way to increasing clouds and low overcast conditions during the early morning hours Tuesday. Zonal flow overhead will turn more southwesterly in response to a mid-lvl disturbance working out of the Great Basin and into the Rockies. This wave will induce lee of the Rockies cyclogenesis with this broad area of low pressure progged to work out into the Central and Northern Plains Tuesday morning. Anticipate an area of snow to develop and push through north central SD prior to daybreak with the bulk of the precip chances filling in across the Missouri Valley during the morning. This will shift eastward into the James Valley and points east during the afternoon hours and linger through the evening before winding down in our eastern zones by late evening and early Wednesday. This mid-lvl compact vort looks to wind up fairly rapidly and shift quickly across SD during the afternoon and evening before exiting east into MN by early overnight. It will induce sfc low pressure across southwest/south central SD by midday and is progged to track east northeast into southeast and east central SD by late afternoon into the evening. Winds don`t look overly impressive with this system. Although there will be some gustiness out of the east initially ahead of the system during the day and then northerly on the backside of the system Tuesday night. There may be a little enhancement of the east winds on the western slopes of the Coteau across Marshall and Day Counties. This combined with falling snow in the afternoon could reduce visibilities for a time. The overall impacts of blowing snow look to be more muted and brief with generally the worst of the conditions occurring during the late afternoon into the first half of the evening. The snowfall could be briefly heavy at times, especially across northern zones between the Missouri and James Valley`s. HREF pings those locales with 1 inch/hr snowfall rates for a short time during the late afternoon and early evening before shifting quickly north into ND. Accumulations will generally fall into the 1-4 inch category across the CWA with the least amounts south and the highest amounts along and north of the US Highway 12 corridor. There may be a locale or two closer to 5 inches right along the ND/SD border. GEFS/GEPS/EC plumes for QPF/snow all seem reasonably agreed upon these with respect to this system with The other caveat that this system looks to deliver is some mixed precip. BUFKIT soundings along with EC meteograms for locales along our southern zones support pockets or areas of freezing precip from around the I-90 corridor in our south northeastward toward the Miller area and then over toward the Watertown area. On the backside of the system, BUFKIT soundings indicate a loss of ice aloft toward the end of the system tomorrow evening as far west as the Aberdeen/Redfield areas. Not so confident in this scenario playing out at this time due to uncertainty of where precip will be falling then. It should be brief in nature however if it does materialize. Temperatures through the entire period will continue to remain well below normal. Lows in the teens with highs in the 20s and 30s looks to be a sure thing going into mid-week. .LONG TERM...(Wednesday through Monday) Issued at 400 PM CDT Mon Mar 20 2023 By 12Z Wednesday the area of low pressure will become nearly stacked from the surface through 500mb over northeastern Minnesota. A dry surface ridge of high pressure will bring some pockets of clearing before high clouds return from the southwest. The cold air advection, lingering longer over our eastern counties, should keep high temperatures near or below freezing Wednesday afternoon. While the next surface low will likely track west to east across KS Wednesday night into early Thursday, the 500mb trough and 700mb low will shift into western SD by daybreak Thursday. Light snow will overspread the region, with the main focus looking to be near and south of the I-90 corridor. There significant differences between the model solutions, with the 00Z run of the operational GFS indicating the potential for heavy banded snow over portions of NE and southern SD. We`ll continue to monitor for a potential northern shift, and where winter weather headlines may be needed. At this point, we`re going with little to no snowfall for our northeast most counties. The 500mb low looks to exit Thursday night. However, the series of upper level waves will continue to swing across the Northern Plains through the rest of the forecast period. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) Issued at 627 PM CDT Mon Mar 20 2023 Terminals KABR,KATY,KPIR,KMBG VFR conditions will prevail early on in the TAF period, although expect MVFR/IFR CIGs to overspread the region late tonight into Tuesday morning as a storm system approaches. -SN/SN is also forecast to spread into the area during the day Tuesday, with MVFR/IFR VSBY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...Winter Weather Advisory from 1 PM Tuesday to 1 AM CDT Wednesday for SDZ005>008-010-011. Winter Weather Advisory from 1 AM CDT /midnight MDT/ to 7 PM CDT /6 PM MDT/ Tuesday for SDZ003-004-009. MN...Winter Weather Advisory from 1 PM Tuesday to 1 AM CDT Wednesday for MNZ039. && $$ UPDATE...TMT SHORT TERM...Vipond LONG TERM...KF AVIATION...TMT
Area Forecast Discussion...Updated
National Weather Service Billings MT
953 PM MDT Mon Mar 20 2023 .UPDATE... The 00Z runs for the models are backing off on the fog potential in southeast Montana. The HRRR and the NAM do still have some lower visibility, but this looks like it will more associated with some snow vs fog. There could still be some low clouds, but the surface winds are also expected to be breezy through much of the night, so the mixing will likely keep things as stratus. Reimer && .DISCUSSION... Tonight through Wednesday Night... Satellite imagery indicated a weakening ridge over southeast Montana with SW flow moving into the south central mountains due to a negative tilt trough moving through Oregon. Clouds were increasing across our region with some light snow on radar over the Absaroka/Beartooth Ranges and nearby foothills. That upper shortwave trough will work into Idaho this evening and cut eastward across northern Wyoming late tonight through Tuesday. So we are looking for increasing snow in the high country this afternoon into the evening while easterly upslope/overrunning and some dynamic lift affect our western foothills and nearby plains. Instability is such that we may see some snow squally type bands in our west this evening. As shortwave progresses east Tuesday it will spread lift and instability east with westerly flow kicking in behind it. Dynamics affect mainly the southern portions of our CWA Tuesday including the Big Horns region and SE MT. In the meantime...models develop some light snow and fog over eastern Montana tonight in the isentropic ascent area ahead of the shortwave...but this should not amount to much. Due to the nature of the instability and track of associated 700mb low, we could see a few areas in west get some intense snow shower bands this evening followed by light snow then west winds kicking in behind the shortwave creating a some lulls in the snow by Tuesday morning. Overall snowfall amounts tonight through early Tuesday will range from about 1-3" in the west and less than an inch in the central zones. Very tricky to determine which areas may see impacts from snow and slick roads...models take road surfaces to freezing by mid-late evening in the west where the most snow may occur. So the Tuesday morning commute may be slick in these areas. Despite below normal confidence in placement of accumulating snow, we will issue a Winter Weather Advisory due to this potential hazard across the western foothills and nearby plains this evening through noon Tuesday. (Paradise Valley, Livingston, Northern Park, Beartooth Foothills, Melville Foothills, Northern SweetGrass) We may need winter weather advisories for SHeridan, Wy to SE MT Tuesday, but will let future shifts get a closer look. Most of this snow may occur during the day which minimizes impacts to travel. However, SE MT (Carter, Powder River) may see 1-3" of snowfall at least on grassy surfaces. Tuesday night should see mostly dry conditions behind the shortwave. However, another un-organized short wave tracks through the central Rockies Wednesday. Currently, ensembles keep most of the energy south of our CWA, but precipitation does spread into our southern border areas including the Absaroka/Beartooths and Big Horn Mtns where some light accumulations area possible. As the upper shortwave energy exits the mountains Wednesday night into eastern Wyoming there is some decent lift that develops over the SE corner of Montana where a couple of inches of snow is possible (mainly Carter/Powder River counties). However, any slight deviation in the track of the upper shortwave could easily change the placement of accumulating snow. Look for highs Tue/Wed mainly in the upper 20s and 30s with perhaps a few locations reaching near 40 on Wednesday in the west. Overnight lows will be in the upper teens and 20s. BT Thursday through Monday... Thursday, clusters show the region in a strange split flow pattern with below average heights. Behind this split flow there is good agreement a trough will enter the region Friday into Saturday. Early next week another trough looks to make its way into the region. This unsettled pattern will bring consistent low precip chances. The best chance for precipitation looks to be Friday into Saturday. Even this looks to be light with NBM giving non-mountainous regions <20% chance for 1/4 inch of precipitation. NBM chances for 48 hour snowfall for this time sit at <30% for the southern CWA. NBM chances for the Bighorns and Absaroka/Beartooth mountains are currently >50% for 4 inches. Before the trough moves in, temperatures will be near normal (40F-50F) for Thursday and Friday. After that the general troughing pattern will bring below average temperatures for Saturday, Sunday, Monday with temperatures generally 5-10 degrees colder. && .AVIATION... Conditions will continue to deteriorate this evening across the region to MVFR/IFR/LIFR from low ceilings and snow/mist. These conditions will expand eastward tonight to impact much of the area. Mountains will be obscured tonight. LT/Arends && .PRELIMINARY POINT TEMP/POPS... Tue Wed Thu Fri Sat Sun Mon ----------------------------------------------------------- BIL 025/037 023/040 022/051 031/048 028/041 023/040 022/046 54/S 03/S 31/B 13/O 43/S 22/S 11/B LVM 026/038 022/036 019/046 026/039 020/035 017/037 017/042 84/S 03/S 31/B 25/S 33/S 32/S 11/B HDN 022/037 018/040 018/052 026/051 026/042 021/041 019/047 43/S 03/S 31/B 14/R 53/S 32/S 21/B MLS 022/030 017/035 017/045 026/048 028/038 022/036 020/043 45/S 01/B 31/B 01/B 22/S 11/E 11/B 4BQ 026/033 020/037 020/046 026/051 027/039 023/037 022/044 47/S 04/S 41/B 02/R 42/S 21/E 11/B BHK 015/027 011/030 012/039 019/043 020/033 016/032 014/038 44/S 01/B 31/B 00/U 22/S 21/E 11/B SHR 020/033 015/034 017/042 020/044 020/035 014/034 014/040 57/S 06/S 41/B 04/S 54/S 33/S 21/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Winter Weather Advisory in effect until noon MDT Tuesday FOR ZONES 40-64>66-141-172. WY...None. && $$ weather.gov/billings
Area Forecast Discussion
National Weather Service Corpus Christi TX
707 PM CDT Mon Mar 20 2023 ...New AVIATION... .SHORT TERM... (Tonight through Tuesday night) Issued at 359 PM CDT Mon Mar 20 2023 Deterministic runs maintain a quasi-stationary upper pattern during the period, except for a high amplitude upper level disturbance predicted to enter western CONUS Tuesday. In response to the quasi-zonal flow, expect deepening low MSLP over the Lee of the Rockies/southern Plains during the period, as predicted. As a result, onshore flow will increase. PWAT values slowly rising today (LAPS analyses) and expect PWAT values slightly above normal Tuesday/Tuesday night. Although patchy light rain/isolated showers may occur tonight, expect the best chance for precipitation to occur Tuesday, considering isentropic lift/low condensation pressure deficits at 300K. Patchy stratus-lowering mist/fog may occur over portions of the CWA 09-13z Tuesday, yet anticipate mainly MVFR visibilities. Will maintain the Moderate risk of rip currents for tonight. && .LONG TERM... (Wednesday through next Sunday) Issued at 359 PM CDT Mon Mar 20 2023 Key Messages: -Windy conditions develop Thursday into Friday ahead of a cold front -Slight chance of thunderstorms and chance of showers late Thursday night into Friday morning A dry weather pattern will continue Wednesday into Thursday as mid- upper level high pressure sits over the Gulf of Mexico. An incoming mid-upper level trough will nudge the high pressure to the east, and give us our next shot at precipitation as it ejects a cold front into the area. Windy conditions will develop as high pressure remains to our east and the trough approaches from the west, causing the pressure gradient to tighten. Winds may reach advisory criteria briefly during Thursday afternoon. This next cold front is not expected to be much of a rain maker. Timing of rain chances appear to be during the overnight hours Thursday into Friday. Current ensemble probabilities show around a 20-30% chance of QPF greater than 0.1" for the northern tier counties. The chances of greater that 0.1" of rainfall increases towards the northern Coastal Bend (30-50%), with the highest probabilities in the Victoria Crossroads (60-90%). Probabilities for accumulations of 0.5" or greater were zero area wide. Did not deviate from previous forecaster`s predictions about thunderstorms with this front. Model guidance still suggests SBCAPE will be limited; however WAA and positive vorticity in the 850mb layer could lead to elevated thunderstorms. PWAT values will be over 1.5" (near 99th percentile) during this time, and will further support rain chances. Temperatures will cool down briefly Friday night. Warm temperatures quickly recover going into the weekend as quasi- zonal flow takes over. Low level moisture will increase through the weekend, with PWATs returning to around 1.5" levels on Sunday. Could see some streamer showers during that time. Timing of the next front is still an issue between models. The ECMWF brings the front through late monday night, while the Canadian and GFS bring it through early Tuesday morning. In any case, went with NBM as far as PoPs are concerned. && .AVIATION... (00Z TAFS) Issued at 707 PM CDT Mon Mar 20 2023 MVFR ceilings will continue to be prevalent across south Texas into the early overnight period. Southerly low level flow will increase to 30-35 knots overnight and continue over the coastal plains through the day Tuesday. SREF probabilities and HRRR model show ceilings will lower to IFR over the Brush Country around 08Z and to the inland Coastal Bend around daybreak Tuesday. Fog will also develop over the northern Brush Country from 10-14Z with MVFR vsbys. Slow improvement of ceilings to MVFR is expected over the Brush Country, while MVFR ceilings persist through the afternoon for the coastal plains. Clouds will scatter out/VFR by the mid afternoon over the western Brush Country. Gusty south to southeast winds are expected on Tuesday for the coastal plains with gusts to over 30 knots at CRP in the afternoon. && .MARINE... Issued at 359 PM CDT Mon Mar 20 2023 In response to deepening low pressure upstream, expect increasing onshore flow during the period. Small Craft Advisory conditions are expected to commence tonight and continue at least through Tuesday night (based on deterministic Global, Mesoscale, and CAM output, expect 20-25kt wind to develop over the coastal waters tonight, yet fall to 15-20kt over the nearshore waters Tuesday. However, the NBM suggests 5-7ft seas over the nearshore waters by Tuesday afternoon, and high seas are expected to continue through Tuesday night. Thus, decided to hoist a continuous SCA for 00z Tuesday to 05z Wednesday, after coordinating with WFOs BRO/HGX). However, anticipate only 15-20kt over the bays, based in part on cool SST values. Moderate to strong onshore flow of 15 to 25 knots and elevated seas will then continue through Thursday night with periods of Small Craft Advisory conditions possible. Chances of showers and thunderstorms increase on Friday as a cold front moves offshore during the day. Brief offshore flow can be expected Friday night with onshore flow returning by Saturday afternoon. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 61 75 68 81 / 20 20 10 0 Victoria 57 73 66 80 / 20 20 10 0 Laredo 60 85 68 90 / 0 10 0 0 Alice 57 77 65 85 / 10 20 10 0 Rockport 61 72 67 77 / 20 20 20 0 Cotulla 58 83 68 90 / 10 10 0 0 Kingsville 60 76 67 83 / 10 20 10 0 Navy Corpus 63 73 69 78 / 20 20 10 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Small Craft Advisory until midnight CDT Tuesday night for GMZ250- 255-270-275. && $$ SHORT TERM...WC LONG TERM....HA AVIATION...TMT/89
Area Forecast Discussion
National Weather Service Cheyenne WY
930 PM MDT Mon Mar 20 2023 .SHORT TERM...(This evening through Tuesday) Issued at 137 PM MDT Mon Mar 20 2023 High pressure remains locked in across the southeast CONUS, as a shortwave continues digging southward into Colorado. Current observations have seen some gusty winds across the I-80 corridor, and snow shower actively moving from west to east near Laramie and further eastward into Wheatland. All in all, no major squalls developed yet today, with only some minor banded snow that dropped visibilities near the terminals to around 1sm and winds remaining under criteria. Main concern tonight includes the continued chance for snow squalls through sunset. HiRes model guidance is still pushing upwards to 200 to 350 J/kg of CAPE along the I-25 corridor from Cheyenne to Douglas and the HRRR hinting at a line of precipitation developing along the boundary as it pushes to the northeast along the steering flow. 700mb winds also remain elevated with some gusts near 40 knots, which support snow squall development. However, confidence remains low at this time for anything noteworthy. Nevertheless, with the HRRR maintaining the development of the snow band later tonight, went ahead and added some POPs to the forecast to account for this model solution and will need to monitor just after midnight for any snow squall potentials. Current observations have seen intermittent snow, primarily from the banded snow that has moved across the zones, with better coverage developing overnight. Snow will begin to taper off during the daytime hours on Tuesday, with a shortwave ridge moving across the CWA, which will briefly increase daytime highs to the low-40s to low- 50s for most areas east of I-25 and bringing us into near-normal temperatures. Next potential wind threat in the next 24 hours include a chance for strong wind across the wind prone areas on I-25 and I-80. Wind threat still appears marginal, with in-house model guidance keeping the wind gusts just under 50 knots and CAG-CPR height gradients dropping from 60 meters with earlier model runs to around 20+ meters. At this time, decided to hold off on upgrading any watches to warnings and will let the evening crew take another look. .LONG TERM...(Wednesday through Monday) Issued at 137 PM MDT Mon Mar 20 2023 The main concern with this portion of the forecast is the timing of the various shortwaves moving through the area during the remainder of the week. A very active pattern will be setting up over the area through the week. The models are showing numerous shortwaves pushing through the jet. The initial shortwave is progged to move towards the forecast area on Wednesday on the left exit region of the upper level jet. It appears like the best lift will be focused over the Sierra Madre range once again with some shadowing possible over the Snowy Range, due to strong southwest flow. The other concern to be on the lookout for is a possible stationary boundary setting up somewhere between Gillette and Douglas. As the shortwave ejects into the northern Plains on Wednesday into Wednesday night it may set the stage for some frontogenesis near the frontal boundary which could affect Converse and Niobrara counties Wednesday afternoon into Wednesday night. Not confident on how this will evolve, but certainly something we will need to keep an eye on. The next concern is the wind after the passage of the shortwave Wednesday night into Thursday. The local in-house models are showing another favorable period for some strong winds mainly for the wind prone areas. The GFS is the only model that is trending to keeping a closed surface low tracking through the northern Wyoming while the GEFS/EPS ensembles and the ECMWF turns this feature into more of an open wave. We are leaning towards more towards an open wave solution for now, which may limit the high wind potential a bit, but it is still certainly something we will need to see how this pans out. The GFS is also showing some signs of some elevated instability in the Nebraska panhandle Wednesday evening before the front moves through Wednesday night which may result in some rain/snow showers. The remainder of the week will continue to be quite active with another disturbance moving through the area on Saturday. This may bring our next chance of rain/snow showers. Regardless, the pattern will continue to be quite cool with highs struggling to get out of the 30s and 40s. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 927 PM MDT Mon Mar 20 2023 A round of -SHSN will move from southwest to northeast during the overnight to early morning hours. This will cause nearly all terminals to transition from VFR to low-end MVFR/IFR as CIGs and VIS decrease between approximately 6Z-12Z Tuesday. SE WY terminals will see the VIS and CIGs reductions 7Z-10Z, and the NE Panhandle terminals will experience -SHSN between approximately 10Z-13Z Tuesday morning. Wind gusts are expected to pick up after daybreak for all terminals, with gusts of 30-35 kts likely after 18Z Tuesday. Winds/gusts should begin to taper off by 0Z Wednesday for all terminals. && .FIRE WEATHER... Issued at 137 PM MDT Mon Mar 20 2023 Fire weather concerns will remain minimal throughout the week due to multiple rounds of precipitation. Rain and snow showers can be expected Monday through Thursday, with snow accumulations possible. High winds are possible for the wind prone areas of southeast Wyoming Tuesday and Wednesday. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Watch from 3 AM MDT Tuesday through Tuesday afternoon for WYZ106-107-110. Winter Weather Advisory until 6 PM MDT Thursday for WYZ112-114. NE...None. && $$ SHORT TERM...MRD LONG TERM...REC AVIATION...BW FIRE WEATHER...SF
Area Forecast Discussion
National Weather Service Wichita KS
712 PM CDT Mon Mar 20 2023 ...Updated Aviation Discussion... .SHORT TERM...(This evening through Thursday night) Issued at 224 PM CDT Mon Mar 20 2023 Bottom line up front: breezy this evening, with increasing shower chances across southern and southeast KS late this evening and tonight. Above normal temperatures for Tue and Wed. shower chances return late in the week. A tight pressure gradient has led to gusty winds over the area for the afternoon hours. winds are currently bumping up against wind advisory criteria, so will keep the wind advisory going until 00z. think the winds will relax some this evening, as the winds decouple and south warm advection increases. Latest RAP suggests that this warm advection/moisture advection will increase late this evening over southern KS, for a chance of showers after 03z, with this moisture transport and shower chances increasing for areas east of I- 135 for the rest of the overnight hours into early on Tue. Even seeing some elevated instability around 500-800 J/KG, so could see a few rumbles of thunder. This moisture transport continues to veer to the east over the Flint Hills and southeast KS for the morning hours on Tue. Areas along and east of the KS Turnpike have the best chance of seeing appreciable rainfall amounts, of a quarter to a half an inch. Expect most of this shower chance to move out of SE KS by around noon. A weak surface trough will continue meander across KS for the rest of Tue into Wed, with SW flow creating nice downslope conditions for most locations with temperatures climbing into the lower 70s on Tue and into the upper 70s across southern KS for Wed, due to compressional heating south of the trough. Could see breezy conditions again on Wed, which will probably lead to another elevated grassland fire risk. The surface trough pushes east of the area for Wed night, with a cold frontal boundary "backdooring" into the area late Wed or early on Thu. A shortwave is expected to move east across the area on Thu, which will lead to increasing chances of showers for initially SE KS, as the cold front stalls over SE KS. But overrunning over the top of the stalled boundary may lead to shower chances increasing for most of southern KS by Thu evening and Thu night. Ketcham .LONG TERM...(Friday through Monday) Issued at 224 PM CDT Mon Mar 20 2023 Lots of uncertainty on how the end of the week will play out, as the GFS shows a quick hitting system moving across NEB, which may lead to a shower chance across northern and central KS by Sat, but the ECMWF is weaker and further north with this system, which may lead to the shower chance staying over NEB and the Dakotas. Ketcham && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 709 PM CDT Mon Mar 20 2023 Areas of rain showers will increase overnight and persist through Tuesday morning across generally the eastern half of Kansas, as a pair of shortwaves approach from the west. Can`t rule out a few rumbles of thunder, but meager instability should keep it mostly showers. Also, MVFR ceilings will increase from the south late tonight and persist into Tuesday morning, in response to low- level moisture advection. Could see some IFR ceilings for a time Tuesday morning, but for now kept things MVFR. && .FIRE WEATHER... Issued at 224 PM CDT Mon Mar 20 2023 Very high fire danger is expected area-wide until the early evening hours. Southerly winds are forecast to continue at around 20 to 30 mph, gusting up to 35 MPH. A modest increase in moisture advection will lead to the grassland fire index decreasing late this evening even with the gusty winds. The fire weather concerns continue through midweek as gusty winds overlap with warm temperatures, and reduced relative humidity. Ketcham && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 42 70 51 79 / 40 10 0 0 Hutchinson 41 72 46 77 / 40 10 0 0 Newton 41 68 50 77 / 50 10 10 0 ElDorado 42 65 53 78 / 60 30 10 0 Winfield-KWLD 43 68 54 80 / 60 30 0 0 Russell 40 70 37 72 / 20 0 0 0 Great Bend 41 71 40 77 / 20 0 0 0 Salina 41 71 43 73 / 50 10 10 0 McPherson 41 70 46 75 / 40 10 0 0 Coffeyville 42 59 53 77 / 60 70 10 0 Chanute 41 58 52 77 / 70 70 20 0 Iola 41 57 51 77 / 70 70 20 0 Parsons-KPPF 42 58 53 77 / 60 70 10 0 && .ICT WATCHES/WARNINGS/ADVISORIES...None. && $$ SHORT TERM...Ketcham LONG TERM...Ketcham AVIATION...ADK FIRE WEATHER...Ketcham
Area Forecast Discussion
National Weather Service North Platte NE
605 PM CDT Mon Mar 20 2023 ...Aviation discussion... .SYNOPSIS... Issued at 420 PM CDT Mon Mar 20 2023 Key Messages: - A warm front brings the threat of freezing rain and wintry mix tonight into tomorrow, which could result in hazardous conditions. Winter Weather Advisory in effect for much of the area. - The next system arrives Wednesday into Thursday, which could bring light accumulations of snow to northern Nebraska. - Temperatures remain near or below normal for the next several days. (normal highs are generally in the mid 50s) Synopsis: Western Nebraska remains in quasi-zonal flow aloft as the primary northern stream lies near the Canadian border and the subtropical jet cuts across the Desert Southwest. A week upper low is moving into the Inland Northwest, while an H7 low near the Black Hills drags an elevated front or shortwave near northern CWA. At the surface, a quasi-stationary front cuts right across the Sandhills, roughly from KCDR to KLBF, then back toward KOMA. Temperatures as of 20z remain near freezing in the far north and have risen into the mid 50s near and south of the front. && .SHORT TERM...(This evening through Tuesday night) Issued at 420 PM CDT Mon Mar 20 2023 This evening and tonight... East/southeast upslope low level flow continues on both sides of the surface boundary, resulting in modest moisture advection. Expect surface dew points to rise from the lower 20s into the upper 20s by sunrise. Isentropic upglide is prevalent at 280-290K along the front, which coincides with the increasing moisture. Guidance suggests the boundary to lift north as a warm front, anchored by the surface low near the Black Hills. Expect some precip development as the low levels moisten and forcing increases, although fog and/or drizzle may precede the activity. Forecast soundings suggest a very shallow saturated layer to start before further saturation occurs after sunrise. Capped PoP to schc or low end chc through 12z. Did not mention fog in the official forecast due to a brief window for optimal development and lower confidence for placement. For min temps, stuck with the general model blend which also lines up with the middle of the NBM envelope. Forecast values range from the lower 20s in the far north to lower 30s far southwest. Tomorrow... A rather complex scenario is in store as the warm front lifts into South Dakota during the morning, and a cold front is quick on its heels, crossing the Sandhills during the afternoon. Meanwhile, a mid-level shortwave brushes the northern Sandhills later in the day. Increased PoP a bit along the Hwy 83 corridor to account for the warm front passage and far north central for both fronts and shortwave. Trended the PoP forecast toward the more aggressive solutions (HREF, NAM), as there is quite a discrepancy in coverage and overall potential for precip amongst the 20/12z model suite. For instance, GFS and HRRR suggest very little recordable moisture and keep it confined to far northern Neb. Did not feel comfortable with the "optimistic" solutions due to the environmental setup of a warm front passage in the wintertime. The current forecast favors a rather quick-hitting round of precip during the morning for western Neb and perhaps some lingering showers in the afternoon for far north central. As for ptype, things could be a mess. The thermal profile changes from very shallow and cold saturation (freezing drizzle), to deeper moisture but with a warm nose and cold surface (freezing rain or wintry mix), to deeper moisture but entirely cold profile (snow), to drier but slightly warmer air (rain/snow mix). Essentially, nearly all types are in play for the heart of the forecast area from 6am-noon. With that in mind, issued a Winter Weather Advisory. Do not expect much snow accumulation due to marginal ground temps and very low SLR`s (1- 4:1), but am concerned about the potential for a glaze of ice. As for the cold front, temp advection is delayed as an H85 thermal ridge actually sets up on the leading edge. In all likelihood, the cool front may merely act as a dry line. With negligible 24 hr H85 temp changes, highs should be fairly similar or slightly milder than today. Winds may also gust over 30 mph behind the front in the panhandle and northern Sandhills. When combined with the influx of drier air, fire weather conditions may be locally elevated in the panhandle. Tomorrow night... A brief lull in activity is anticipated as the cool front exits the CWA, high pressure settles in at the surface, and flow aloft transitions to southwesterly. Weak cool air advection begins with northerly flow at H85. Forecast lows range from the upper teens far north to upper 20s far southwest. .LONG TERM...(Wednesday through Monday) Issued at 420 PM CDT Mon Mar 20 2023 The main forecast beyond tomorrow revolves around the next storm system slated to affect western and north central Nebraska Wednesday into Thursday. A lee side surface low spins up in eastern Colorado later Wed and rides the NE/KS border through early Thu. The subtle upper low approaches from the north during the same time, and the main H3 jet noses right into the CWA. The jet may be particularly intense with a streak of 140 kts. Currently, the most favorable location for persistent precipitation and cold enough temps for snow is Hwy 2 and north. The greatest potential for accumulating snow, mainly on the order of 1 to 3 inches, lies closer to Hwy 20. Across southwest Neb, the air may stay warm enough to keep precip as rain/snow mix or all rain. The synoptic pattern remains unsettled heading into the weekend as well, with low end PoP to round out the forecast period. Highs should stay in the 40s or 50s the next several days (or 30s far north), while lows stay in the 20s to around 30. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 605 PM CDT Mon Mar 20 2023 VFR early, trending to IFR/LIFR towards daybreak with icing possible. Satellite and surface observations indicate generally mid/high clouds across central and western Nebraska early this evening, and expect this will remain the case until low clouds surge in from the east late tonight. Expect IFR/LIFR due to low cigs and vsbys, with a wintry mix of precipitation and a glaze of ice on aircraft surfaces from just before daybreak through Tuesday morning. While precipitation will diminish by early Tuesday afternoon, Do not expect significant improvement in flight conditions until late Tuesday morning with VFR conditions becoming established once again toward the end of the valid period. Winds may be a bit gusty at issuance but expect laminar conditions to become established early with a light easterly surface wind thorugh tonight. Winds veer around to the west late in the period but look to remain 10kt or less. && .LBF WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 4 AM CDT /3 AM MDT/ to 4 PM CDT /3 PM MDT/ Tuesday for NEZ005-006-008-009-023>026-035>037-057-059- 094. && $$ SYNOPSIS...Snively SHORT TERM...Snively LONG TERM...Snively AVIATION...MBS
Area Forecast Discussion
National Weather Service San Francisco Bay Area
610 PM PDT Mon Mar 20 2023 .SYNOPSIS...High winds and widespread rainfall tomorrow, with High Wind Warnings out for the Monterey and San benito mountains and Wind Advisories from the San Francisco Bay Area to the Monterey County coast. Scattered showers persist into Wednesday and unsettled pattern continues into next week. Monitoring potential for unseasonably cold temperatures next weekend, and a new storm system the beginning of next week. && .DISCUSSION...as of 03:11 PM PDT Monday...A break in the rain for the rest of today as winds remain light and mainly clear, with highs in the lower elevations in the mid 50s to low 60s, and into the mid 40s to low 50s for the higher elevations. A storm system is approaching California and will impact the SF Bay Area and Central Coast starting early on Tuesday. While the system is associated with an atmospheric river approaching the state, the main moisture tap will be directed to our south in southern California and Baja California. For our area, winds will be the main issue, with the most impactful gusts Tuesday morning into the afternoon. A High Wind Warning is in effect from 7 AM to 9 PM Tuesday in the mountains of Monterey and San Benito Counties, where southerly gusts of over 70 mph are expected. Elsewhere, a Wind Advisory is in effect for the East and South Bay, the San Mateo Peninsula, and the lower elevations of the Central Coast, also from 7 AM to 9 PM Tuesday, with southerly wind gusts of up to 40-50 mph are expected, with more intense gusts in the higher elevations. The North Bay should see gusts of up to 20-25 mph. Much of the uncertainty in the strength of the wind gusts is in the wider SF Bay region, as models are still having difficulty on the location of a surface low that`s expected to enhance wind gusts. The global GFS and European models are bringing the low to a stall off the coast of the San Mateo Peninsula, while the higher resolution HRRR and NAM are bringing the low onshore along the Central Coast. We will continue to closely monitor the surface low and its evolution as the impact comes closer. Rainfall will be a secondary impact in our area, although expected totals are not as high as those in southern California. here too, the most intense rain is expected Tuesday morning and afternoon. The lower elevations of the North Bay, SF Bay Area, and Central Coast are currently forecast to see three-quarters of an inch to one inch of rain, save for the most northern parts of Sonoma County where rain totals go down to half an inch. The Central Coast mountains remain the regional epicenter of rain impacts, with rain totals in the Santa Lucia mountains expected to range from 2 to 3 inches, and the Santa Cruz and interior Monterey and San Benito mountains expected to reach 1.5 to 2.5 inches of rain. Higher elevations in the Bay Area should expect 1 to 2 inches of rain. A slight chance of thunderstorms exists into the post-frontal environment on Tuesday evening, especially on the Central Coast. The combination of continued rain, high winds, and saturated soils poses a set of hazards that, at this point, are now familiar to many in our region. The rain brings a chance for minor urban and small stream flooding, and with soils already so saturated from the storms earlier this month, the risk of shallow landslides continue. High wind gusts will also result in downed trees and power lines, possibly resulting in isolated power outages, and difficult driving for high profile vehicles. If your area is prone to power outages, use today to prepare, and remember to "turn around, don`t drown" when encountering a flooded roadway or path. The heaviest rain diminishes Tuesday evening, with post frontal showers expected through Wednesday. Current predictions leave Thursday to Saturday relatively dry with very little, if any, rain. Any rain that falls in the next three days is not expected to rise past half an inch in total. All attention then focuses on the beginning of the next week, where early model indications suggest another system coming through, the exact details of which won`t become clear until later in the week. In addition, low temperatures next weekend are expected to dip into unseasonably cold readings, with lows in the low to mid 30s expected Saturday and Sunday morning in the interior valleys, including the Sonoma, Napa, and Salinas Valleys, and into the higher elevations. With the occurrence of "bud break" in the North Bay vineyards, and the Spring harvest approaching, this is a particularly sensitive time for the agricultural industries. More details on the low temperatures and the system next week will come as the forecast gets refined later in the week. && .AVIATION...as of 05:30 PM PDT Monday..For the 00z TAFs..VFR with breezy onshore flow continuing through the evening. By early Tuesday morning, E/SE winds begin to increase as a strong surface low approaches the coastline of Central CA. This low pressure system will also bring moderate to heavy rain starting early morning lasting through the afternoon with scattered showers continuing through the evening. MVFR conditions prevail during this time. As the low approaches and moves inland, southerly winds will increase through the morning and afternoon. Strong gusts of 35 to 40 knots possible across the region, primarily south of the Golden Gate. Winds begin to diminish by the end of the TAF period. Vicinity of KSFO...VFR continues with breezy northwest winds diminishing tonight. Rain expected to arrive at the terminal around 12Z with high confidence of MVFR conditions as the rain passes through. Winds will turn easterly early morning Tuesday and increase as low approaches. Winds shift SE as low moves inland and eventually out of the SSE/S. Wind gusts become strongest between 20z and 04z with gusts up to 35 knots (but potentially higher depending where low sets up and will continue to monitor). SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR with breezy onshore winds that are slowly diminishing. SE winds increase starting early this morning around 09z. Strong SE winds will continue beyond 09z and increase further during the afternoon with gusts around 35 knots with up to 40 knots possible. Moderate, to at times of heavy, rain will accompany the increased winds. && .MARINE...as of 03:11 PM PDT Monday...Expect the moderate winds to decrease through much of the day, with a diminishing northwest swell prevailing. A strong low pressure system arrives tonight and lasts into mid week. This will bring widespread rain and strong southerly winds especially in the southern waters, where isolated gusts could reach storm force. A west swell will combine with wind wave to create high and steep seas. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tday...Wind Advisory...CAZ006-508>510-512>516-528>530 High Wind Warning...CAZ517-518 SCA...SF Bay SCA...Pt Arena to Pt Reyes 0-10 nm SCA...Pt Reyes to Pigeon Pt 0-10 nm GLW...Mry Bay GLW...Pigeon Pt to Pt Pinos 0-10 nm GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm GLW...Pigeon Pt to Pt Piedras Blancas 10-60 nm SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 3 AM SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 3 AM SCA...Pt Arena to Pigeon Pt 10-60 nm && $$ PUBLIC FORECAST: DialH AVIATION: McCorkle MARINE: Miles Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea