Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/24/23

Area Forecast Discussion
National Weather Service Binghamton NY
926 PM EST Mon Jan 23 2023 .SYNOPSIS... A few lake effect snow showers or flurries will continue tonight into Tuesday across the area. The next winter storm then moves through the area Wednesday into Wednesday night, with snow changing to a wintry mix and even rain. Colder air moves back in by the end of the work week with lake effect snow showers possible Thursday into Friday. && .NEAR TERM /THROUGH TUESDAY NIGHT/... 930 PM Update... Winds have shifted to more westerly, ending the Finger Lake effect and starting to ramp up lake effect snow coming off of Lake Ontario. Areas along and north of the NY Thruway will see scattered snow shower chances through the overnight hours. The forecast remains on track from this afternoon`s forecast package. Temps, PoPs and snowfall amounts were slightly adjusted to account for current trends and updated high res models. Snowfall continues to remain light over the region, with far northern Oneida county getting around 2-3in, with isolated spots around 4 inches across higher terrain in the Tug Hill. 630 PM Update... Finger Lake showers continue SSE of the lakes this evening. Flow will begin to shift from the NW to WSW over the next couple hours, ending the Finger Lake effect showers. Snow chances will then focus up north across Oneida county. Amounts are expected to be light, with less than a half inch across the Finger Lakes into Oneida county. Far northwest Oneida county could see an inch of light fluffy snow through the overnight hours. The forecast remains mostly track from the last update. Updated PoPs and snow amounts to match Finger Lake showers and adjusted winds to match current trends and latest high res guidance. 345 PM Update Quieter weather overall in this period. There will be some scattered snow showers and flurries around Central NY and the northern tier of PA this evening into tonight under the cold northwest flow. There is some enhancement off the Finger Lakes and Lake Ontario. Additional snow amounts will be light, under 1 inch. The snow showers should lift north after midnight as the flow backs more westerly. Northwest winds will be blustery overnight, between 10-20 mph with gusts of 25-30 mph over the higher elevations. This could cause some localized blowing snow over the open areas in the higher terrain. Overnight lows dip down into the 20s tonight areawide. By daybreak Tuesday, a cold front will be approaching from southern Canada across western NY. This front could bring some snow showers and perhaps even some brief heavier snow squalls to areas mainly along and north of I-90. As the band of snow tries to move southeast, it looks to weaken rapidly with only flurries down into the Twin Tiers. Scattered lake effect snow showers continue into Tuesday afternoon across the NY Thruway corridor and points north. By afternoon there is some instability noted and steeper lapse rates, so this again could be a period for isolated heavier snow showers or squall across our northern areas (Syracuse, Utica, Rome). At this time NE PA looks to stay dry Tuesday, with even a few breaks of sun possible. Daytime highs only reach the low to mid-30s and west winds continue to be quiet blustery at 15-25 mph. By Tuesday night there will be localized on going lake effect snow showers mainly along and north of the Thruway. The boundary layer wind gradually backs more west, then even west-southwest late at night. This will shift the lingering lake effect snow northward through the night. Total snow accumulations tonight through Tuesday night along and north of the NY Thruway are forecast to range from 1 to 2 inches, with locally up to 3 inches across far northern Oneida county. Considering these low amounts, no winter headlines were needed. The rest of the forecast area remains dry Tuesday night under mostly cloudy skies. Colder overnight lows dip down into the upper 10s to mid 20s. Winds diminish and eventually turn southerly just out ahead of the next, fast approaching system. 330 am update... A coastal low is beginning to deepen early this morning based off of surface observations with a mesoscale snow band developing from central PA extending NW into the Tug Hill. Rap reanalysis shows a 850 to 700 mb frontogenesis band set just SE of the snow band. This FGEN band will likely start progressing east as the coastal low deepens and moves into the Gulf of Maine through the morning. Based off of model guidance this bad will be moving mostly perpendicular to the flow which will reduce its residence time in any given area. With the best forcing aloft slightly displaced from the FGEN band, snow fall rates under it have been around an inch an hour getting ti 1.2 to 1.4 inches an hour at times based on NY mesonet sites in the Southern Finger Lakes. This snow band will likely be just exiting the Southern Tier around morning commute time but starting likely will affect much of NEPA during the commute. Behind the exiting FGEN band, dry air will be advecting in above 850 mb. The dendritic growth zone dries out with snow ending from west to east through the morning hours. Snow showers likely linger in the Catskills into the mid afternoon with the help of some upsloping across the higher terrain. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... 300 PM Update... Attention turns to the next system that will move into the region Wednesday. A low will move across the Ohio Valley on Wednesday with precipitation extending well into the northeast. Conditions will be cold enough for snow initially. Some weak FGEN banding could support some brief heavy snow showers during the daytime. Strong winds will blow snow, reducing visibilities at times. As the low moves into the eastern Great Lakes region, a secondary low along the coast begins to develop. A warm front will also drift northward, bringing warmer conditions into the region. Some light snowfall accumulations will be possible late in the day before snow transitions to a brief period of frozen mix as this warm air surges northward. As temperatures warm, this frozen mix then transitions to rain. The uncertainty is how far north this warm air can make it. Precipitation in areas north of the warm front would stay as snow or frozen mix. A dry slot moves in between these two systems, so precipitation becomes much lighter over portions of CNY and NEPA. Model guidance has trended downward with precipitation amounts, which is also reflected in this latest update. It certainly looks like most of the area will receive at least a few inches of snowfall on Wednesday. Higher amounts will be possible in the southern portions of the Poconos and Catskills as well as in north-central NY. Given the uncertainties with this system, no headlines were issued with this update but this system remains highlighted in the HWO. This complex system moves out of the region Thursday morning. Wrap around moisture becomes lake enhanced under northwest flow as a frozen mix transitions to just snow showers across most of the region. As the system moves out of the Northeast, colder air fills in behind it. Northwest flow will also remain present, supporting lake effect snow showers in CNY through the overnight hours. Additional light snow accumulations are expected through Thursday night. In the typical lake effect areas, an additional few inches will be possible. Temperatures during the daytime on Wednesday will only be in the low to mid 30s. With the push of the warm front overnight, temperatures will warm up a few degrees from the daytime high with the forecasted lows being reached in the evening hours. The highs for Thursday will be in the mid to upper 30s. Temperatures Thursday night drop into the teens and low 20s with that colder air moving in. Stronger winds combined with the cooler temperatures will result in some periods of blustery conditions both days. Wind chills Wednesday will be in the teens, but single digit winds chills are then expected during the overnight hours on Thursday. && .LONG TERM /FRIDAY THROUGH MONDAY/... 300 PM Update... This period will remain active as multiple waves/weak system pass through the region. Lingering lake effect snow showers will be possible Friday, though high pressure and drier conditions will help cut these off. This dry period will be brief as the next system sweeps through on Saturday. With the center of this system well north of the region, the best chance for snow will be north of the Twin Tiers. A quick round of snow showers and wintry mix comes on Sunday as a frontal boundary sits across the northern portions of the region. Heading into early next week, a stronger system looks to bring another round of wintry precipitation and colder conditions. The end of the week will remain cool but then milder conditions are expected through the weekend and possibly into early next week, depending on the timing of the next system. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... MVFR ceilings in place should remain in place throughout the TAF period. KELM and KAVP may lift to VFR at times mainly after 15Z Tuesday. Gusty westerly and northwesterly winds should decrease later this evening but then increase to around 20 knots again on Tuesday. Brief period of MVFR snow showers possible at KRME and KSYR as well. Outlook... Tuesday night...VFR for northeast PA, with occasional MVFR CIGs still lingering for Central NY sites. Wednesday and Thursday...Storm system will bring snow changing to wintry mix and rain. Restrictions likely. Friday and Saturday... Some MVFR ceiling restrictions with a chance of snow showers. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MJM NEAR TERM...JTC/MJM SHORT TERM...BTL LONG TERM...BTL AVIATION...MJM/MWG
Area Forecast Discussion
National Weather Service Burlington VT
703 PM EST Mon Jan 23 2023 .SYNOPSIS... Lake effect snow showers will develop across St Lawrence County overnight tonight. A strong cold front could produce some brief heavy snow showers and even a few squalls across northern New York and Vermont during the day on Tuesday. The quick intense burst of snow accompanied by strong gusty winds could lead to greatly reduced visibilities and treacherous road conditions where squalls develop. After brief quiet weather Tuesday night into early Wednesday, our next winter storm arrives late Wednesday into Thursday with the potential for widespread plowable snowfall and mixed precipitation. Quieter weather prevails on Friday into early Saturday before more unsettled weather and below normal temperatures return late Saturday into early next week. && .NEAR TERM /THROUGH TUESDAY NIGHT/... As of 605 PM EST Monday...Upper air analysis shows mid/upper lvl shortwave ridging building into our cwa, while plenty of stubborn low level moisture lingers. Clouds are prevail acrs most of our cwa with a few breaks on the downslope side of the dacks acrs eastern Essex County, NY, while some light snow shower activity continues acrs parts of southern VT and slopes of the central Green Mountains. Have tweaked pops to show lingering snow shower activity acrs Rutland/Windsor Counties and chc pops in the central Green Mtns this evening. Any accumulation wl be minor. Did bump temps up by several degrees due to more clouds, especially CPV with lows ranging from upper teens NEK/lower CT River Valley to mid/upper 20s elsewhere. Already noticing additional snow shower activity developing over the northern Great Lake associated with our next system for Tues. Crnt idea of expanding precip chcs looks good with some lake enhanced moisture impacts the western dacks/southern SLV late tonight into Tues, ahead of approaching cold frnt. Fcst remains in good shape overall with just some minor tweaks needed. Previous discussion below: * Winter storm exits the region with lingering upslope snow showers. In addition, lake-effect snow showers will develop across portions of St Lawrence county overnight. * A sharp cold front will produce a few brief, heavy snow showers and possibly a few squalls across northern NY and VT. Upslope snow showers will continue for the Green Mountains and even down to the Champlain Valley including Burlington during the afternoon into evening hours thanks to subcritical Froude number favoring blocked flow along with remaining low level moisture. But the bulk of the snow accumulation and travel impacts will wind down by late afternoon into early evening hours as the surface low pulls away in the Gulf of Maine. So mostly quiet weather during the Monday overnight hours. The exception is towards southern St Lawrence county where lake-effect snow will likely develop. This is due to steepening mid-level lapse rates and impressive delta T between top of the boundary layer (-12C at 850mb according to RAP soundings) and the relatively mild water temperatures (39F or +4C at Rochester, NY this morning) will trigger enough instability and vertical motion to kick start the lake effect band. Some uncertainty with regards to the precise location of the band but given it is 230 or 240 degree WSW wind off Lake Ontario, odds favor the southern portion of St Lawrence county. Given that winds could gust up to 30 kt at times, certainly could make for some blowing snow as well given the relatively higher SLRs of almost 15:1. Then a brief but decent lobe of 500mb shortwave energy digs into Ontario and crosses our region in the Tuesday morning hours. The associated vertical motion will help moisten the 800-600mb levels which associated with the thermal profile, will help create an anomalously deep dendritic growth zone (DGZ) that will help to deliver a burst of moderate to localized brief heavy snowfall. SLU CIPS model guidance are indicating some potential for squalls across our northern zones that may coincide with the Tuesday morning commute. Not a blockbuster or widespread event by any means given that the primary surface low is forecast to track way to our north across northern Quebec. However, the timing may prove to be problematic for morning commuters given that visibility could be greatly reduced for 15 to 20 minutes at any given location due to falling/patchy blowing snow. Fortunately, it does not look like a flash freeze scenario given the temperature profile and trends. Finally, this is a conditional threat especially across the Champlain Valley. As with warm season convection, how widespread the snow squalls get depends on whether we can get at least partial clearing during the day and mix out the low level inversion. So thinking that locations like BTV could get the brief heavy snow shower or squall to come through during the afternoon or early evening hour - so potentially coinciding with the evening commute along the actual cold front. The snow squall or heavier snow shower activity comes to an end by sunset with partially clearing skies overnight. With a fresh snowpack on the ground, this should help with radiational cooling across the region with seasonable overnight lows in the single digits and teens. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... As of 349 PM EST Monday...Cycle of active weather looks to continue, but Wednesday will be the reprieve from the action. Dry air will briefly reside across the region. There could be some glimpse of sunlight early, but high clouds will start streaming overhead once more as an upper ridge crests over the area. Snow starts to move in during the evening and overnight. So we`ll live the short term as "short" and note a seasonable day with high temperatures in the mid 20s. All told, it should be a relatively nice winter day with gradually increasing east to northeast winds. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 349 PM EST Monday...Snow should start pushing into the region about 5 PM Wednesday as warm, moist advection along and ahead of the warm front approaches the area. Towards 8 PM and 3 AM Thursday, precipitation rates could become heavy at times, as cyclonic vorticity advection coupled with steep 8 C/km lapse rates aloft and supportive jet dynamics allow for good snowfall rates. The ratios could be difficult, as southeasterly flow at 850hPa accelerates to 40 to 50 knots, which could fragment dendrites. QPF amounts appear modest, with likely 0.33" to 0.50" attached to the warm front alone, which should deliver a quick 2-5" of snow on the front end, even if snow ratios end up on the lower end. As the mid-level low center tracks near the St. Lawrence Valley, warm air will lift into Vermont, along with a dry slot. Precipitation will become more scattered in nature across Vermont, with some wintry mix lifting into much of the region, with perhaps even plain rain into Rutland County and where warm air funnels up the Connecticut River Valley. This window should be relatively short, about 3 to 6 hours, before the low shifts east Thursday morning. Northwesterly flow and deformation as the mid-level low moves overhead should bring us back to all snow fairly quickly. With plenty of upstream moisture and Froude values near 1, a transition towards terrain driven snow benefiting our mountain regions should wrap up the event. In total, amounts should range about 3-7" in the Champlain Valley and Northeast Kingdom from terrain downsloping with some mix involved, 6-9" in favorable upslope regions and along the St. Lawrence River, and a tentative 4"-8" south due to a mix and some dry slotting. Mountain summits should range about 9-12". This is rather general, and anticipate as we get into the range of mesoscale models, that terrain effects will become more amplified, but based on trends, it appears we will once again need headlines for the upcoming event. It looks like the active weather continues in the extended range. After a relatively quiet Friday-Saturday morning, a polar front will swipe the region Saturday evening and bring below normal temperatures over the weekend, along with snow showers across the region. Then an "Ohio Valley Runner" type low quickly shifts into the area to bring another dose of snow early next week. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... Through 00z Wednesday...MVFR, and possibly IFR cigs at MPV, RUT, and SLK, will prevail across most terminals through 12Z with northerly blocked flow and plenty of boundary layer moisture, resulting in lingering low clouds and a few light snow showers through 03Z. As a narrow ridge of high pressure crosses the region, north to northwest winds around 10 kts in Vermont will join northern New York with a light west or southwest wind developing between 04Z and 08Z. After 11Z, winds will become breezy with gusts to around 20 kts ahead of a cold front and pre-frontal trough. Lake-enhanced snow showers will cause numerous snow showers to develop in northern New York, impacting MSS and SLK through much of the period. Aside from RUT, all terminals may see snow showers after 18Z ahead of the cold front with best chances at EFK; elsewhere, VCSH is offered at this time given the scattered nature of expected showers. Winds turn more northwesterly again between 20Z and 00Z with gusts gradually diminishing. Outlook... Tuesday Night: VFR. Slight chance SHSN. Wednesday: VFR. Chance SN. Wednesday Night: Mainly MVFR and IFR, with local VFR possible. Definite SN, Definite FZRA. Thursday: Mainly MVFR, with local IFR possible. Definite SN, Chance SHSN, Definite FZRA. Thursday Night: Mainly MVFR, with areas VFR possible. NO SIG WX. Friday: VFR. NO SIG WX. Friday Night: VFR. NO SIG WX. Saturday: Mainly MVFR, with areas VFR possible. Chance SHSN. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Chai NEAR TERM...Chai/Taber SHORT TERM...Haynes LONG TERM...Haynes AVIATION...Chai/Kutikoff
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
835 PM EST Mon Jan 23 2023 .UPDATE... A short wave trough is driving a narrow region of snow extending from the straits down to central Lake Michigan. This trough will track across Se Mi overnight. The better height falls will remain north of the forecast area. The brevity of ascent combined with the ample mid level dry air in place across Se Mi will be the main limiting factor for precip. Given the upstream returns, an brief window of better moisture depth, a low chance for light snow showers overnight appears warranted across the northern half of the forecast area. Little to no accumulations are expected with any activity that makes it into Se Mi. && .PREV DISCUSSION... Issued at 555 PM EST Mon Jan 23 2023 AVIATION... The latest RAP and NAM soundings suggest the ongoing subsidence will cause low clouds to remain trapped under a deepening inversion this evening. This will result in continued MVFR based clouds with some subtle lowering cloud bases. There has however been been an area of clearing which has expanding across southern Lake Mi and far SW Lower Mi. There seems to be some potential that this clearing will work inland this evening. However, a weakening cold front will move across the region from the northwest overnight, reinforcing some low level moisture. Thus any clearing that is able to work into Se Mi will be brief. The weakening cold front will at least support a brief chance for light snow or flurries overnight. The extent of low level clouds again remains in question on Tuesday as differential thermal advection will boost the inversion base. However, upstream observations suggest post frontal low level moisture may again favor MVFR based clouds. DTW THRESHOLD PROBABILITIES... * Moderate in ceilings below 5000 feet tonight and Tuesday. PREV DISCUSSION... Issued at 344 PM EST Mon Jan 23 2023 DISCUSSION... A weak cold front will pass through the area tonight as a upper level trough works southeast through the Great Lakes. While there may be a few flurries with this feature, particularly focused off to the northeast of the forecast area, no notable precipitation is expected. Even with the passage of the cold front, temperatures will not cool off too much with high temperatures ranging into the lower to mid 30s again on Tuesday. The main focus for this forecast will remain the winter storm system that will eject from the southwest CONUS/far northern Mexico tonight into Tuesday on into the Ohio Valley and southern Great Lakes by Wednesday. There were no major surprises in the model solutions from the 12z cycle with a similar north to south prognostic envelop in terms of where the center of the resultant surface cyclone tracks and hence where the heaviest band of snowfall occurs as the system passes just south of the area. The region remains on the northern periphery of this heavier swath of snow, but southern portions of the forecast area definitely remain within an area that will likely experience some enhanced banding/FGEN as a TROWAL feature arcs back around the cyclonic circulation of the low. Will issue a Winter Storm Watch with this forecast package for Lenawee/Monroe/Wayne counties as consistency in model solutions suggest there is at least a 50/50 chance of around 7 inches of snow over far southeast lower Michigan from parts of Wednesday morning into the evening as heavier snow shifts off to the east. As is often the case, a slight shift southward in the track of this system will limit these totals somewhat while a shift north would bring higher totals further north into the area. Model solutions, in aggregate, lean more towards a steady solution to one where the system edges a bit south. However, the main southern shortwave remains slightly cut off from the main flow late today, so the re- integration of the system on Tuesday may bring some fluctuations in the exact track such that a more northern track into the region cannot be dismissed out of hand just yet. Within the watch area, average total snowfall during roughly a 12 hour period from Wednesday morning to Wednesday evening may reach 7 inches or so with lighter amounts in the 2-6 inch range further north through the forecast area. Amounts will taper off fairly quickly the further north one goes through the area. With the main storm event still 48 to 54 hours away, some slight modifications to the watch may yet occur before the eventual delineation between a Winter Weather Advisory and Winter Storm Warning is made. Snow showers will taper off quickly Wednesday night as this system progresses to the east coast. The weather pattern thereafter looks to remain fairly active as a clipper shortwave brings additional snow showers late week into the early weekend. In the wake of this system, arctic high pressure from the Yukon into southern Canada will gradually spread south/southeastward. At least one, and quite possibly two systems will track along the southern periphery of this arctic airmass and bring the potential for meaningful snow to the area from late this weekend into early next week. At the same time, colder conditions will evolve with highs in the 30s late this week transitioning to the 20s into the end of the forecast period and quite possibly colder than that by next week. MARINE... Cold front over the western Great Lakes this afternoon will swing through the Central Great Lakes tonight. Southwest winds over Saginaw Bay already approaching 25 knots late this afternoon. Low level wind speeds look to be maximized this evening, and strongest winds will reside across Central Lake Huron where a brief gust to low end gales appears likely. Otherwise bulk of the wind gusts should hold around 30 knots, and small craft advisories remain in place. Limited snow showers expected with the frontal passage. Decent low level cold advection Tuesday morning, but pressure gradient will be diminishing quickly, and westerly winds are expected to hold around 20 knots before winds trend light and variable for Tuesday evening/night. A winter storm/low pressure system still on track for the mid week period, with the center of the low moving through the eastern Great Lakes Wednesday night. Widespread snow and increasing northeast-north winds for the Central Great Lakes. Northeast-north winds topping out between 30-35 knots appear likely, especially across the southern Lake Huron basin. Leaning toward the bulk of the gusts remaining just under gale force, but ultimately will be dependent of the strength of the low and how fast the second low pressure center near New York city becomes the main low and tracks into New England on Thursday. Strong southwest flow returns for Friday ahead of an Arctic front, and gusts to gales are possible over the open waters of Lake Huron by Friday evening. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...Winter Storm Watch from Wednesday morning through Wednesday evening for MIZ076-082-083. Lake Huron...Small Craft Advisory until 7 AM EST Tuesday for LHZ421-441. Small Craft Advisory until 4 AM EST Tuesday for LHZ422-442-443. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ UPDATE.......SC AVIATION.....SC DISCUSSION...DG MARINE.......SF You can obtain your latest National Weather Service forecasts online at
National Weather Service Sioux Falls SD
502 PM CST Mon Jan 23 2023 .SHORT TERM...(This Evening through Tuesday) Issued at 130 PM CST Mon Jan 23 2023 KEY MESSAGES: 1. Fog potential for tonight growing once again, dense fog again possible. 2. Nuisance snow events possible through the middle of the week, with potentially more impactful snow to end the week. 3. High confidence on a sustained and significant drop in temperatures for next weekend and into the week beyond. ----------------------------------------------------------------- THIS AFTERNOON: Frontal boundary continues to travel east this afternoon, with winds begins the front turning to the northwest in many locations. Temperatures have generally warmed behind the boundary with a slight westerly downslope component. Stratus will slide continue to slide southeast, and have generally followed the HRRR track. TONIGHT: Fog will again be the greatest concern into the overnight hours. Surface winds are expected to turn light and even variable after sunset tonight and then gradually turn to the southwest after midnight. With skies clearing, this should allow for good radiational cooling over the deep snowpack, with weak warm advection intensifying over the increasing surface inversion after midnight. Melting this afternoon will leave cross-over temperature rather high, which should result in fog formation later this evening. Some guidance suggests rapid development of dense fog pushing northeast along the highest elevation of the Plateau by daybreak Tuesday. Will hold off on an advisory, but one may be needed later tonight. TUESDAY: Another weak surface front will approach the area from the west after daybreak. Light winds may keep stratus stuck in the I-29 corridor and points east through the morning. The passage of the surface front early in the afternoon should scour any stratus, and actually lead to another surge in afternoon temperatures towards the freezing mark. A small risk of flurries with the passage of the front, but have left the forecast dry for now. .LONG TERM...(Tuesday Night through Monday) Issued at 130 PM CST Mon Jan 23 2023 TUESDAY NIGHT: Fog will again be possible Tuesday night into Wednesday as winds remain light. An increase in mid-lvl clouds thanks to an approaching mid-lvl trough could prevent strong radiational cooling. Some flurries or very light snow could be possible by daybreak Wednesday. WEDNESDAY-THURSDAY: Models in strong agreement that a compact mid- lvl trough moves into western Minnesota by daybreak Wednesday. Moisture depth could prevent a more substancial snowfall, but could see a period of very light freezing drizzle switching to light snow as the lower profile shifts towards the lowering DGZ through Wednesday morning. A ridge of high pressure moves across the areas along I-29 Wednesday night, as another weak impulse slides through the western Dakotas early Thursday. Latest guidance suggests any precipitation with this system stays just west of the CWA. THURSDAY-FRIDAY: The nose of an upper jet slides into the Dakotas early Thursday, and should produce a significant amount of mid-upper cloud. This jet will also help provide upper support as a fast moving clipper travels through the Northern Plains. A corridor of warm advection snow develop into Friday morning, and may be strong enough to produce a couple inches of accumulations by time it slides into the Great Lakes by Friday morning. An increasing SPG may result in wind gusts up to or over 30 knots Friday morning, increasing the risk for some travel impacts. Have pushed winds higher than populated NBM guidance. Behind the passage of the surface front, temperatures may warm into the 30s Friday afternoon/evening. SATURDAY-MONDAY: Medium to extended range guidance remains in strong agreement that an arctic front arrives in the region for next weekend. Colder air begins to move into the Tri-state area early Saturday morning, with a 1040 mb surface high moving down the Front Range by the end of the weekend. Ensemble guidance indicates high probabilities of below zero temperatures into early next week (AOA 90%), with potential for 24 or more hours below zero. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) Issued at 458 PM CST Mon Jan 23 2023 Main aviation concerns will once again be fog. Many signs point towards some fairly quick development between 3-9z and if it does develop will likely be in the IFR and LIFR categories. The lowest visibilities will likely be from about 6z to 15z with the better chances east of the James River. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ SHORT TERM...Dux LONG TERM...Dux AVIATION...08
Area Forecast Discussion
National Weather Service Goodland KS
628 PM MST Mon Jan 23 2023 .UPDATE... Issued at 626 PM MST Mon Jan 23 2023 Patchy dense ground fog has developed across Kit Carson and Sherman counties. Quarter mile visibility has consistently been recorded on both the KGLD and KITR ASOS sites, along with visual confirmation (especially across open areas) at the NWS Goodland office. Have issued a short SPS to address the fog and will continue to monitor for any expansion of the fog. && .SHORT TERM...(This evening through Wednesday) Issued at 100 PM MST Mon Jan 23 2023 20 UTC Water Vapor Imagery and RAP analysis indicated strong closed low circulation moving across Arizona and New Mexico. Another low amplitude trough was moving across Minnesota. At the surface 1026mb ridge was centered over the Colorado and Kansas border, with light winds across much of the outlook area. Primary concern for the short term will be fog potential tonight followed by limited snow threat tomorrow and Wednesday. For tonight, majority of near term models suggest boundary layer will rapidly saturate tonight with fresh snow cover aiding in radiational cooling. Concerned that we may simply radiate through the current dewpoints resulting in frost as some weak vertical mixing of drier air aloft is possible. Despite this concern profiles indicate a saturated layer depth between 500 and 1000 feet so am leaning towards the fog solution. That being said, hard to really pick an area more favorable than any other so confidence in issuing any highlight too low at this point. On Tuesday, aforementioned closed low will move across central Texas, significantly south of the storm track from this past weekend. While there is a small chance that northern fringe of precipitation will reach CWA, mainly Greeley and Wichita counties, but seems like the limiting streamline around this low should keep precipitation out of the area. On Wednesday increasing northerly winds and low level CAA will keep temperatures from improving much at all through the day. Of particular interest is the potential for low level instability to develop due to differential CAA. Potentially certainly exists for diurnally driven snow showers, especially north of the Kansas border. At this time, do not expect it to amount to more than a few flurries. .LONG TERM...(Thursday through Monday) Issued at 1253 PM MST Mon Jan 23 2023 The long-term period is still looking to remain generally mild, albeit cool, with a chance of precipitation and very cold temperatures starting Saturday night. A trough will move east while northwesterly flow will move into the Tri-State area Thursday and Thursday night. This will help keep the region`s temperatures slightly below normal, especially the daily maximum temperatures. This northwesterly flow will become primarily zonal by Saturday morning. As it stands, Friday and possibly Saturday are the only two days that the area could warm above freezing. As the flow becomes zonal, the polar jet stream will be flowing near the CWA. Model guidance is showing signs of a trough pushing the jet stream slightly south Saturday. This will bring another arctic airmass into the Tri-State area. This airmass could give us another chance at precipitation and likely very cold temperatures. We expect low level moisture to begin moving into the region on Saturday. This could lead to very low cloud levels, and possibly fog and light flurries. Currently, Saturday night will be the best time to see accumulating snow, however this will be limited by available moisture and forcing mechanisms where any moisture is located. Overnight low temperatures will be near or below 0F with northerly winds gusting between 19-22 kts. This will create minimum wind chill values below -15F for the entire Tri-State area. Sunday will be dominated by mostly cloudy skies and northerly winds that will keep us cold. High temperatures will likely not get higher than the mid teens at best. Sunday evening, a high pressure system looks to move eastward to the north of the CWA. This will cause winds to become easterly and eventually southerly on Monday, and will usher out the arctic air. However, Sunday night will once again be dangerously cold with low temperatures dropping to less than -5F for the entire Tri-State area. Wind gusts over 15kts are still likely which will lead to wind chills of near -20F for majority of the CWA. Monday will begin a slow warming trend as the arctic air begins to leave. Confidence that very cold temperatures will impact the Tri-State area at the start of next week is moderately high and increasing. The chance for precipitation with this system is still up in the air. A limiting factor will be the amount of available moisture. There will likely be ample low-level moisture available, however the ECMWF and GFS are showing a dry layer in the mid levels. The models are showing ample moisture to the north of the CWA, so if that mid- level moisture shifts south, more precipitation is possible. Another factor is the availability of lift. A strong inversion around the 750-800 mb height will limit off deep lifting potential. However, near the surface, soundings are showing conditionally unstable thermodynamic profiles. This setup could create a variety of solutions including light snow, freezing fog, or a wintry mix/combination of these. It is possible that light flurries could continue from Saturday until Monday night. Confidence of impactful precipitation from this is currently low and steady. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 350 PM MST Mon Jan 23 2023 Broken to overcast skies are present across the area with MVFR ceilings already occurring at KMCK. KGLD may see a period of fog/low ceilings during the evening hours but am however a little skeptical of it and duration as I am currently anticipating something similar to yesterday evening with a fluctuation of 3-6sm ceilings due to fog. Opted to go with a tempo for now to see how it plays out. Some guidance does show fog going down and staying down through the morning. Ceilings will lift after sunrise back to VFR through the end of the period. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...Trigg SHORT TERM...JRM LONG TERM...CA AVIATION...Trigg
Area Forecast Discussion
National Weather Service North Platte NE
522 PM CST Mon Jan 23 2023 ...Updated Aviation Discussion... .SYNOPSIS... Issued at 255 PM CST Mon Jan 23 2023 Key Messages: -Snow showers are possible Wednesday afternoon and evening, with the potential for rapid visibility reductions in any showers. -Additional snow chances exist Friday and into the weekend across much of western and north central Nebraska. -Much colder temperatures and the potential for dangerous wind chills are anticipated Sunday and beyond. && .SHORT TERM...(This evening through Tuesday night) Issued at 255 PM CST Mon Jan 23 2023 Currently, cloud cover persist across much of the area, with temperatures hovering around freezing. Aloft, westerly and largely confluent flow prevails with a deep upper low centered over southern Arizona. At the surface, the area sits on the northern periphery of an expansive surface high, centered over portions of the Mid-south. A surface trough stretched from portions of eastern Nebraska into northern Kansas, in association with a surface low over Ontario. For today and tonight, patchy fog will again be possible across portions of southwest into central Nebraska, generally near and south of the I-80 corridor. However, this remains somewhat low confidence, as lingering cloud cover along with winds transitioning west-southwesterly could limit this potential somewhat. Still, with much of southwest and central Nebraska reaching/exceeding the freezing mark, any snowmelt would add additional credence to high- res guidance painting an area of fog into tomorrow morning. This will need to be monitored, and localized areas of dense fog would be possible if patchy fog should develop. A cold front drops through the area tomorrow afternoon, though near neutral advections behind the boundary suggest limited temperature change with its passage. This cold front is in association with a weak surface low dropping across the Dakotas. The most notable effect of the front will be a wind shift from southwest to northwest, with winds increasing to around 10-15 mph. Lows tomorrow night again fall into the teens, amid persistent cloud cover. .LONG TERM...(Wednesday through Monday) Issued at 255 PM CST Mon Jan 23 2023 A few different systems look to impact the area midweek into the weekend. Confidence remains low in details, though the potential exists for medium (to locally high?) impacts across western and north central Nebraska. The first looks to arrive Wednesday afternoon, as a northern stream H7 trough drops southward across the upper midwest into Wednesday evening. As the H7 trough axis dives through the area during the afternoon, lapse rates steepen markedly in the mid-levels. Some guidance suggests the potential for clearing skies ahead of this mid-level feature, which also steepens lapse rates in the lowest few kilometers. Non-zero CAPE would be possible across portions of the Sandhills and northern Nebraska, leading to the possibility of convectively enhanced snow showers. This will be driven to a large degree by the amount of diurnal heating areas receive, and this makes for low forecaster confidence. However, should areas receive ample sunshine for very low, albeit nonzero, CAPE, an area of show showers are possible, primarily north of I-80. Rapid and significant visibility reductions would be likely an any convective snow bursts. Quick, light accumulations on roads would also be possible. This will need to be monitored closely, as localized high impact could be possible. Additional light snow chances linger into late week as a few shortwaves are progged to drop into the central CONUS in the mean northwesterly flow aloft. By Saturday, a stronger shortwave will drop into the Intermountain West, pushing eastward into Wyoming through the evening. The approach of this wave leads to increasing FGEN in the mid-levels, which should translate to an area of frontogenetically forced snowfall moving across the area. Exactly where this occurs remains low confidence, and largely tied to the exact track of the parent upper low. However, confidence in at least some accumulating snowfall is beginning to grow, especially across portions of western Nebraska. This looks to occur just ahead of an encroaching artic airmass, leading to a quick increase in SLRs. The snowfall Saturday will be much drier and fluffier than in previous storms, along with much lesser QPFs anticipated. With systems of this nature, efficient snowfall processes could lead to a narrow swath of significant accumulations and this will need to be monitored going forward. As for the artic airmass, confidence continues to grow in a period of bitterly cold temperatures returning Sunday and continuing into the following week. Highs in the single digits to teens and lows well below zero are beginning to look likely. Though winds do not look overly strong in any one period, the cold temperatures will lead to the potential for dangerously cold wind chills with any wind speed. Those with outdoor interests should continue to monitor later forecasts, and begin preparations for a period of dangerous cold as we head into late this weekend and next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 521 PM CST Mon Jan 23 2023 The latest SREF probabilities are likely for IFR ceilings and visibilities by 06Z tonight and continuing until at least 15Z Tuesday across southwest Nebraska. This includes the KLBF terminal and have included in the 00Z TAF. The latest HRRR and RAP visibilities also are in agreement. MVFR ceilings are currently in place across the panhandle and southwest Nebraska. At KVTN, VFR ceilings are forecast the next 24 hours. Will monitor for possible MVFR ceilings developing tonight at KVTN. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Brown SHORT TERM...Brown LONG TERM...Brown AVIATION...Roberg
Area Forecast Discussion
National Weather Service Louisville KY
1052 PM EST Mon Jan 23 2023 .Forecast Update... Issued at 1051 PM EST Mon Jan 23 2023 Pretty quiet evening with high pressure in control and just a few thin cirrus drifting in from the west. Temperatures have dipped into the upper 20s to lower 30s in most places. As for the Tuesday night storm, still watching 00z model data trickle in. Of note, the 24.00z run of the HRRR trended back northward and now has the southern edge of the accumulating snow near Louisville. This is more in line with the rest of the HREF members from the HREF run. The 23.12z HREF mean and PMM supported a swath of 2+ inches of snow in our northernmost CWA (Jasper IN to Madison IN and north). The dynamics for this low pressure system are quite impressive and include: a coupled upper level jet structure and strong divergence aloft, strong mid-level ascent (including DGZ), and favorable position in the northeastern quadrant of the sfc low 06-12z Wednesday. Snowfall amounts will come down to p-type, particularly the thermal profile from 700 mb down to the sfc. SDF forecast soundings show marginal temperatures in this layer, and depending on the model and sfc low track, a 1-2 degree fluctuation over any of that 1000-700 mb layer will make the difference between rain and snow. There is model agreement showing meaningful evaporative cooling in the low to mid levels after 00z Wed as the column saturates. Despite a strong southerly LLJ nosing in from the south, the wetbulb effects may be enough to support mainly wet snow as the dominant p-type across southern IN and far northern portions of central KY. Confidence is increasing in a 3-5 hr window for wet, slushy snow (heavy at times) over southern Indiana during the early morning hours of Wednesday. Exactly how far north/south the rain/snow transition sets up remains uncertain, but forecast confidence is reasonably high in 1+ inches of snow in southern Indiana. And assuming p-type remains all snow until we lose saturation aloft around 12z Wed, 2+ inches of snow would be reasonable to expect from Jasper to Madison IN and north. Again, still watching 00z data come in so confidence is not quite there for a headline. But have issued a Special Weather Statement to highlight the greater snow accumulation potential along and north of the Ohio River. && .Short Term...(This evening through Tuesday) Issued at 318 PM EST Mon Jan 23 2023 Stratus has blanketed much of the region for most of the day, but as upper ridging and surface high pressure move towards the Lower Ohio Valley, the stratus layer should continue to dissipate from west to east. Areas along the western edge of the CWA are already noticing clearer skies and more sunshine. Tonight, surface high pressure will slide towards and then quickly jet across Tennessee. This will continue the clearing and keep light southwest winds over the CWA. Temperatures are expected to fall into the mid to upper 20s. Depending on how much the region can clear will determine how low the temperatures can go. Tomorrow should start off mostly sunny with a few high level clouds working in from the southwest ahead of the low pressure system bringing our chance for snow Tuesday night into Wednesday. Southern winds and early clear skies should be able to lift temperatures into the mid to upper 40s across most parts of the CWA. Some in southern Kentucky could even see 50 degrees. In the afternoon, mid-level clouds will begin filling in from the west to the east. .Long Term...(Tuesday night through Monday) Issued at 315 PM EST Mon Jan 23 2023 ...Accumulating Snow Possible Across the Area Tuesday Night - Wednesday Morning... Key Messages... * A low pressure system lifting through the Ohio Valley will bring a mix of rain and snow to the area Tuesday Night - Wednesday Morning * Confidence on snowfall totals remains low as subtle shifts in the low pressure track will have a large impact on our p-type * Chances for moderate to heavy snow will "shut off" by Wednesday mid-morning as drier air moves into the area * Gusty winds of 30-40+ mph will be possible Wednesday morning and afternoon * Light snow showers/flurries will be possible Wednesday night through Thursday, additional minor accumulations possible Discussion... Tuesday Night - Wednesday... At the start of the extended period, a potent mid-level shortwave will be lifting northeast out of the Southern Plains towards the OH Valley, moving into the Lower Great Lakes region by Wednesday night. At the surface, an associated area of low pressure initially over Louisiana will lift north and east through the Lower MS Valley and into the OH Valley, deepening as it moves towards the area. Precip will begin to push into the area Tuesday evening after 25/00Z although may initially struggle to reach the ground as model soundings indicate a notable dry layer below 700mb to start. By 25/06Z, PoPs will ramp up across the area as strong isentropic lift moves over the region on the nose of a 50-60+ kt southerly LLJ. P-type remains a bit of a question mark as model guidance differs in its handling of the surface low track, with any subtle shifts in the track having a large impact on our p-type and resultant amounts/ accumulations. Models with a more northern track (such as the GFS) bring largely rainfall to the area and keep the snowfall generally along and north of the Ohio River, while models with a more southerly track (such as the HRRR) shift the axis of heaviest snow into north-central KY along with snow chances across the entire area. For now will try to take a blend of possible solutions, with the best chances for accumulating snow along and north of I-64. Precipitation is then expected to taper off Wednesday morning as the dry slot works its way into the area, although may continue to see some precip chances across southern IN and portions of north-central KY depending on the surface low track. Gusty winds are expected Wednesday morning and into the early evening hours as the low passes through the area, with gusts of 30 to 40 mph possible. Wind direction will initially be out of the east, then shifting around to the south and eventually the west as the low lifts out of the area. Wednesday Night & Beyond... In the wake of the surface low, will continue to have chances for light snow showers or flurries Wednesday night into Friday as several minor shortwaves rotate through the cyclonic flow aloft. Moisture and lift will not be nearly as strong as with the Tuesday night system, but still enough in place for some minor snow accumulations (of less than an inch) to be possible. Dry weather expected for Saturday with our next chance of rain moving in for Sunday into Monday as a cold front moves through the area. && .Aviation...(00Z TAF Issuance) Issued at 624 PM EST Mon Jan 23 2023 Summary: VFR throughout this TAF period Discussion: The stratus deck is currently moving out of the region, giving way to thin, high clouds. Light winds out of the southwest will persist through the night and into tomorrow. Tomorrow evening around 0Z, ceilings will begin to lower as a low pressure system will begin to impact the region. Also around this time, winds associated with this system will begin to shift from the southwest to the east. Confidence: High && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...EBW Short Term...KDW Long Term...JML Aviation...SRM
Area Forecast Discussion
National Weather Service Norman OK
540 PM CST Mon Jan 23 2023 ...New AVIATION... .SHORT TERM... (This evening through Tuesday) Issued at 320 PM CST Mon Jan 23 2023 A strong upper level system moving across the Southern Plains still expected to produce widespread measurable snow and a potential winter storm across parts of our area on Tuesday. An upper trough currently digging across the southwestern U.S. is expected to start moving into the Southern High Plains by early Tuesday morning. All deterministic models continue to have a good handle both temporally and spatially having this system making a southerly track across the Ark-La-Tex region with the upper low over northern Texas/southern Oklahoma through the eastern half of Oklahoma by the overnight hours. Still no surface boundary/cold front coming through our area with its surface low tracking across southern Texas. Although very cold Canadian-based air aloft flowing down through the trough, the lack of a colder air mass coming through at the surface is a bit of a challenge with respect to forecasting wintry precipitation verses rain as well as snow accumulations, although the lack of a warm nose due to very cold air and ice being produced in a very saturated dendritic zone would strongly favor snow type. With POPs likely across our southwest by sunrise Tuesday and definite across our entire area by noontime, surface temperatures will likely stay at wet-bulb hovering near freezing allowing wet snow to accumulate at the ground. Although ground temperatures may be warm, any heavy intensity snow falling will likely accumulate, although more quickly on grassy surfaces than concrete/roadways. Latest HRRR guidance showing a heavy intense band developing across western north Texas through southwest Oklahoma after sunrise, then over a portion of central Oklahoma by the afternoon. As a result, the heaviest snowfall accumulations of 4- 6 inches will be possible within the aforementioned heavy band, which is where we have a Winter Storm Watch for heavy wet snow in effect. Of course this may have to be adjusted as the event occurs based on radar trends. We have 1-4 inches of snow accumulations across the remainder of our forecast area which is under a Winter Weather Advisory, with the highest amounts near the watch area. && .LONG TERM... (Tuesday night through next Sunday) Issued at 320 PM CST Mon Jan 23 2023 Expecting snow precipitation ongoing Tuesday evening, especially across the eastern half of our forecast area. We should see the snow tapering off after midnight Wednesday as the main upper trough axis will have shifted to our east, with all POPs gone by mid- morning. There could be some travel issues Wednesday morning as freezing to just below freezing temperatures combined with a wet snowpack could produce some icy surfaces. Although still under a weak and dry upper trough through the end of the week, we should still see a gradual warming trend with seasonably average temperatures by Friday. However with a possible snowpack Wednesday, temperatures may end up being slightly cooler than our current projections for that day. South winds make a breezy return on Saturday with temperatures warming above average. A potentially strong cold front may come through Saturday night with gusty north winds as both GFS & ECMWF are in good agreement. Light rain across southeast Oklahoma will be possible Saturday night with this frontal passage. Could see a blast of wintry cold Canadian-based air return behind Saturday nights cold front, as the 1000-850 mb critical thickness surges into the Southern Plains. As a result, will see a cooling trend start Sunday into early next week. && .AVIATION... (00Z TAFS) Issued at 538 PM CST Mon Jan 23 2023 Flight conditions will deteriorate very quickly tomorrow morning from SW to NE as an upper level storm system delivers widespread rain and snow. IFR to LIFR cigs and visbys will be possible for most terminals and will persist into the evening hours. Thankfully, it will be a wet snow and freezing rain is not expected. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 31 36 30 40 / 10 100 80 0 Hobart OK 30 34 26 41 / 20 100 60 0 Wichita Falls TX 33 38 29 43 / 40 100 60 0 Gage OK 27 34 24 41 / 20 100 60 0 Ponca City OK 29 37 29 41 / 0 90 80 0 Durant OK 34 39 32 45 / 10 100 90 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Winter Weather Advisory from 6 AM Tuesday to 6 AM CST Wednesday for OKZ004>013-015-017>020-024>026-044>048-050>052. Winter Storm Warning from 6 AM Tuesday to 6 AM CST Wednesday for OKZ014-016-021>023-027>043. TX...Winter Weather Advisory from 6 AM Tuesday to 6 AM CST Wednesday for TXZ086>090. Winter Storm Warning from 6 AM Tuesday to 6 AM CST Wednesday for TXZ083>085. && $$ SHORT TERM...68 LONG TERM....68 AVIATION...03