Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/24/22

Area Forecast Discussion
National Weather Service Goodland KS
803 PM MST Wed Feb 23 2022 .UPDATE... Issued at 756 PM MST Wed Feb 23 2022 Model data this shift continues to indicate the potential for a narrow band of snow to form over the northwest part of the forecast area overnight into Thursday morning. Frontogenesis, convective lapse rates, and isentropic lift over the northwest part of the forecast area during this timeframe are favorable for this band of higher snow amounts forming. The last 5 or so runs of the HRRR have been highlighting this part of the forecast area for higher snow amounts, but differ in the location of the band. The last two runs of the HREF, and several runs of the RAP also favor a band forming over the northwest part of the forecast area tonight. Snow probability of the 25th percentile shows almost three inches north of Wray, which adds confidence that advisory level snow will occur under the band of snow. Due to model variability with the placement of the band, confidence is not high enough issue an advisory at this time. Will highlight the potential for these higher snow amounts with other products in the meantime. These snow amounts will add to the hazardous conditions of the cold wind chills tonight. && .SHORT TERM...(This evening through Thursday) Issued at 235 PM MST Wed Feb 23 2022 A Wind Chill Advisory has been issued for a portion of the area along and west of the eastern Colorado border region between 8pm MST tonight and 8am MST Thursday morning. The primary concern in the short term is the possibility of Advisory level Wind Chill values Wednesday night into Thursday morning. Overnight low temperatures in the single digits above and below zero will combine with mainly light east to southeast winds overnight and early Thursday morning to produce wind chill values as low as 15 to 20 degrees below zero. Along with the cold wind chills, light snow is expected to develop after midnight as the upper trough currently moving through the Intermountain West moves east of the Central Rockies tonight and across the central High Plains Thursday morning. The best lift associated with the upper trough occurs between midnight tonight and mid-day on Thursday, and will correspond to the highest snowfall accumulations across the area. Snowfall amounts will generally be light with a range of one half inch to 2 inches across the forecast area. The greatest accumulations are expected across southwest Nebraska and along the northern Kansas border area. Snow tapers off Thursday afternoon as the upper trough moves east of the area. Overnight lows Thursday night into Friday morning will be in the single digits above and below zero range again with some clearing and light and variable winds that become light out of the southwest. Wind chill values will range from 5 to 15 below zero. Confidence is low, but there may be some locations that could dip briefly down to wind chill advisory criteria overnight Thursday night into early Friday morning. The cold air begins moving out of the region on Friday and Friday night as another short wave trough aloft sweeps across the region and the upper ridge over the western U.S. approaches from the west. .LONG TERM...(Saturday through Wednesday) Issued at 150 PM MST Wed Feb 23 2022 For this long-term forecast period, the weather is looking much better in terms of warmth and the lack of wintry precipitation. The Tri-State Region will reside between split flow, or between the northern and southern jet streams. This will keep any impactful weather systems well north or south of the forecast area. That being said, fire weather parameters will need to be monitored as a result of the forecast warmth, particularly for Tuesday and Wednesday when winds are higher. For this weekend, no weather concerns are currently anticipated. The warming trend that begins on Friday shall continue throughout the weekend. Afternoon high temperatures Saturday should rise into the 40s, while Sunday will bring afternoon high temperatures in the 50s, approaching 60 in some locales. West winds of 10-15 mph are currently forecast, so overall the fire threat should be low although if stronger winds are forecast or observed for Sunday, it is possible that near-critical fire weather conditions are observed. Currently though, based on other forecast parameters that factor into fire weather forecasting, it does not appear Sunday will be a fire weather day. Going into next week, the warming trend will take a brief pause Monday before continuing for Tuesday and Wednesday. Forecast guidance indicates a lee trough should take shape along the Front Range Tuesday. As this trough forms, warm air will advect in from the southwest, pressure gradients will tighten, and winds should increase. This, along with persistent dry weather and dry air advection into the region, could set the stage for a few fire weather days, particularly on Tuesday and Wednesday. There is still some uncertainty in the forecast this far out as guidance varies depending on which model is utilized. However, the general upper level pattern would favor fire weather potential so will continue mention of potential fire weather conditions for middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 428 PM MST Wed Feb 23 2022 VFR to MVFR conditions forecast. Low clouds will move in tonight with the light snow. Am not expecting the snow to be much of an impact. The snow will end from southwest to northeast. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Wind Chill Advisory until 8 AM MST /9 AM CST/ Thursday for KSZ001-013-027-041. CO...Wind Chill Advisory until 8 AM MST Thursday for COZ090>092. NE...Wind Chill Advisory until 8 AM MST Thursday for NEZ079. && $$ UPDATE...JTL SHORT TERM...LOCKHART LONG TERM...RRH AVIATION...JTL
Area Forecast Discussion
National Weather Service Green Bay WI
516 PM CST Wed Feb 23 2022 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Thursday Issued at 333 PM CST Wed Feb 23 2022 The latest RAP analysis and satellite/radar imagery show scattered to broken daytime convective clouds spreading south off Lake Superior early this afternoon. Light snow showers continue over northern Door counties, but these should diminish by the start of the evening as low level winds back around to the west. Otherwise, arctic high pressure was centered over the northern Plains and slowly drifting towards the region. The next storm system is taking shaping over the desert southwest and is poised to impact the region on Thursday. Forecast snow timing and amounts are the focus in this part of the forecast. Tonight...The arctic high pressure will slide towards the state slowly. As the desert southwest system ejects into the western Plains late, mid and high clouds will be increasing overhead. Cloud heights will generally remain above 10 kft so most of the region will remain dry. The exception will be near the Lake Michigan shoreline, where a convergence zone will develop in lake induced troughing. With strengthening northeast or east synoptic flow, a mid-lake snow band remains projected to shift towards the northeast WI shoreline after midnight. The highest chance continues too look like areas over southeast Kewaunee and Manitowoc counties where around a half inch could fall by 6 am Thursday. Low temps could fall quickly over the northwoods this evening before clouds increase late. Lows to range from around 10 below to 15 below over Vilas county to 10 to 15 above over east- central WI. Thursday...The lake snow band will gradually lift northwest over the course of the day, possibly moving into southeast Door county in the afternoon. High resolution guidance doesn`t portray a relatively strong band, and the movement should also limit potential accumulations. Snow amounts along the lakeshore could reach to around 1 inch by the end of the afternoon. Meanwhile, increasing upper divergence and backing mid and upper flow will support an area of light snow moving into the region from the southwest to northeast in the afternoon. Thermal profiles are favorable for dendritic snow growth thanks to a deep isothermal layer. This should result in high snow ratios that could push accums up to 1 inch over parts of central Wisconsin by 6 pm Thursday. Will hold off on a winter weather advisory for tomorrow considering forecast amounts may only reach or slightly surpass an inch by 6 pm Thu. High temperatures will range from the mid teens in the north to low 20s in the south. .LONG TERM...Thursday Night Through Wednesday Issued at 333 PM CST Wed Feb 23 2022 Main focus of the long term will be the snow totals and possible headlines for the accumulating snow Thursday night into early Friday. Otherwise, fairly quiet late February weather is expected as the upper flow turns west/northwest, with only a couple weak, fast moving clipper-type systems pushing across the Great Lakes. Temps will be below normal on Friday, then near or slightly above normal readings this weekend into early next week. Thursday night into Friday...expecting a light to moderate snow event for most of the area, with the exception being far north central WI where little to no snow is expected. Expect the forcing associated with the deformation band over central WI to wane in the evening, and re-focus farther south and east as the surface low passes well to our south and a sharp mid-upper level trough crosses the area. Period of impressive forcing within the DGZ, especially over east central WI, where the DGZ spans from 2,000-12,000 ft for a time. This will combine with some lake enhancement from Lake Michigan with favorable delta Ts and inversion heights. Snow ratios of 20+ are expected at times, where these features overlap. Boundary layer winds become more northerly after midnight, which will keep the enhancement over the lake later in the night. As it looks now, where the best lift/QPF occurs, an advisory snow is likely, mainly over the far southeast CWA. However, after collaboration with surrounding offices, we will hold off on an advisory for now. Thinking central WI will stay just below criteria, and east central WI won`t see the more significant impacts until later Thursday evening. Northeast to north winds will gust up to 25 mph will create some minor blowing and drifting. Everything wraps up by around 12z Friday with only some lingering light precip possible in the morning before drier air works in. Lows look to drop below zero over north central WI, with single digits to lower teens across the rest of the area. Highs will be upper teens to middle 20s. Rest of the long term...flow turns westerly on Saturday then northwest on Sunday. Quiet weather is expected. Southwest to west winds will get gusty on Saturday, as the gradient tightens up ahead of a frontal boundary, with gusts to 30-35 mph expected. The front looks to come through mainly dry, with only a few light showers possible, mainly over northern WI. The next shortwave and associated clipper system will take aim across the area later Monday. Still too many differences in timing and location for the model blend to include chances, but some snow chances will eventually need to be added. && .AVIATION...for 00Z TAF Issuance Issued at 516 PM CST Wed Feb 23 2022 Light snow showers over Vilas and northern Door counties will diminish as low level winds back around to the west this evening. Generally quiet weather is expected from this evening through the rest of the taf period. Mid and high clouds will increase across the region ahead of the next storm system overnight into Thursday morning. The most uncertainty revolves around evolution of a snow band as it drifts into northeast WI off Lake Michigan late tonight into Thursday morning. The latest high resolution models show the band arriving late tonight into Thursday morning. There is some potential for MVFR/IFR vsbys as the snow arrives, but it should be moving and therefore tried to handle the scenario with a tempo. Light snow will generally overspread the area on Thursday afternoon and should expect deteriorating conditions after 18-20Z. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......Bersch AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service Grand Rapids MI
Issued by National Weather Service Northern Indiana 622 PM EST Wed Feb 23 2022 LATEST UPDATE... Aviation .DISCUSSION...(This evening through next Wednesday) Issued at 255 PM EST Wed Feb 23 2022 Persistent lake effect snow showers have come to an end across the bulk of the region by late this afternoon thanks to a gradual weakening and shift in winds to more northerly. Exception has been along the lakeshore (particularly Ludington) as satellite and obs have shown little change in that nearshore band. Expectation is more of the same at least through the evening commute until winds turn more northeasterly around/after 00Z cutting off lake moisture. While some lingering cloud will prevent a bottoming out of temps tonight, light northeast flow leads to a chilly night as lows drop into the teens with single digits possible north of US-10. Mid/upper level trough over the intermountain west ejects east into the southern Plains late tonight reaching the mid-Mississippi valley by Thursday evening. Baroclinic zone currently draped from the Ohio Valley into the Ozarks is drawn northward toward lower MI in response to this wave as associated cyclogensis occurs across the Tennessee/Ohio Valleys. Newly formed surface low pressure advances into southern OH Thursday evening allowing the leading edge of isentropic ascent to reach the I-94 corridor by 00Z Friday with light snow overspreading the remainder of the CWA by 06Z. High consensus among the deterministic runs this morning for the main ribbon of PV/mid-level to cross west MI between 09Z and roughly 12Z Friday morning. PV wave likely enhances the persistent isentropic ascent with additional forced ascent leading to a modest uptick snowfall rates with internal probabilities showing a increase in chances of rates approaching or reaching 0.5"/hr for areas south of US-10 in the 09-12Z timeframe. Snow ratios also look to increase in this period as winds turn northerly on the backside of the low drawing colder air back into the region. 850mb temps drop from -8 to -10C around midnight down to -13 to -15C by 7AM Friday. Strong CAA cools to column with forecast soundings showing deep layer saturation between 900-700mb dropping into the DGZ enhancing ratios. That said, limiting factor will be available QPF which only looks to be 0.10" or less. NAM and RAP have been most aggressive on rates at snow onset (of 0.25"-0.5"/hr) late Thursday (~00-03Z) evening along/south of a Kalamazoo-Lansing line owing to elevated frontal forcing along the edge of the baroclinic zone. Overall total accumulations of 1 to 3 inches are possible (lowest amounts toward the northern CWA) though wouldn`t rule out a local 4" amount south of the Kzoo-Lansing line if the initial rates late Thursday evening come in higher like what the NAM/RAP suggest. System clears west MI by 15Z Friday morning ending synoptically forced snow. Lake aggregate troughing over Lake Michigan lingers through the rest of the day Friday allowing for some lake effect snow showers to persist into Friday evening. Winds first half of the day will be out of the north favoring bands being confined near the lake shore. As high pressure builds into the region from the central Plains, winds back to northwest/west northwest Friday afternoon evening increasing potential for snow showers to move further inland. High pressure should become established enough to taper off any lingering lake effect by Friday night. Temperatures slowly moderate over the course of the weekend as the arctic airmass pushes east. Another arctic front drops through the region late Sunday however is still expected to be a dry fropa. This airmass currently looks to glance west MI with the core staying to our north and east. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 612 PM EST Wed Feb 23 2022 High pressure arrives tonight and then vacates the area during the afternoon hours tomorrow allowing a rise of CIGs out of MVFR and into VFR for the southern TAF sites during the first few hours of the TAF period. Then, expect CIGs to fall again and a chance for precipitation to arrive during the last few hours of the TAF period, but will let the next forecaster time out the precip with the next TAF forecast. Winds will be veering more easterly and then southeasterly ahead of the approaching low pressure wave through the forecast period. && .MARINE... Issued at 255 PM EST Wed Feb 23 2022 Small Craft Advisories remain in effect through late this evening before gusty onshore north/northwesterly flow and elevated waves gradually subside as high pressure expands eastward from the upper Midwest into the northern Great Lakes. Winds will veer more easterly in direction and be moderate in strength Thursday in response to developing low pressure ejecting out of the mid-Mississippi Valley and eventually into the northern Ohio River Valley Thursday night into Friday morning. This low will bring a round of snowfall to all of the nearshore waters. Behind the departing low, strong high pressure will settle into the central Plains with low pressure traversing eastward towards Hudson Bay. Onshore winds backing to the west will increase with a tightened pressure gradient leading to likely small craft conditions for the weekend in ice free areas. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory until 10 PM EST this evening for LMZ844>849. && $$ DISCUSSION...KDK AVIATION...Roller MARINE...IRL
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1039 PM EST Wed Feb 23 2022 .SYNOPSIS... A nearly stationary front will linger over our region through early Friday. The next big low pressure moves northeast along the front Thursday and Friday bringing more rain chances mainly for the mountains. The front is forecast to cross our area late Friday with dry and cooler conditions prevailing into Saturday. Another low could move up from the Gulf on Saturday and Sunday, with more precipitation, including possible mountain snow. Expect drier conditions next week. && .NEAR TERM /THROUGH THURSDAY/... As of 1036 PM EST Wednesday: Dense fog has been settling in across the area from the Lakelands and lower Piedmont of SC up across the outer reaches of the Charlotte metro area. This area held onto the cloud cover past peak heating this past afternoon, thus didn`t have as far to go to cool off to saturation once the clouds thinned and the sun went down. In fact, some locations over the nrn Upstate have already cooled below their fcst low temps by a few degrees, altho guidance insists the temp might actually rise a bit overnight. Visibility has been more steady over the past hour, and the near term guidance has picked up the signal with indications the dense fog will stick around through daybreak. So, we have issued a Dense Fog Advisory now instead of dumping in the lap of the next shift. The fog should start to mix out over the NC Piedmont first, perhaps before sunrise. Otherwise, rain chances look to increase near daybreak across western NC and portions of NE Georgia and the SC Upstate. However, CAMs are not in good agreement regarding the placement of rain overnight into Thursday. The HRRR and ARW show PoPs increasing across much of the CWA early Thursday morning into Thursday afternoon whereas the NAM and FV3 have a few scattered showers across the CWA, but keep most of the rain to our north and west. This leads to lower confidence than usual regarding PoPs through the near term period. Capped PoPs to likely across the far northern NC counties, with slight chance to chance PoPs elsewhere. With sfc high pressure extending into the area from New England on Thursday, winds will become NE`ly allowing cold air damming to develop. This will lead to a tricky high temperature forecast. Temps look to be the coolest across the western NC Piedmont and northern NC mountains. Highs should be near to a few degrees below normal across the NC Piedmont, with above normal temps expected elsewhere. High temps will be monitored closely and will likely need to be adjusted as needed to account for the CAD on Thursday. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... As of 200 pm EST Wednesday: The period will begin Thursday evening with a wedge front draped solidly across the northern half of the forecast area. There will likely be some light residual southerly upglide ongoing over the surface damming layer, and at least chance PoPs will be needed early to account for this. The numerical models have the wedge layer retreating northward overnight, but it is always questionable how much airmass recovery occurs during the nighttime hours without a scouring mechanism. At any rate, will pare back PoPs overnight east of the mountains. Meanwhile, a surface wave lifting along the central Appalachians Thursday night will drag a trailing cold front into the southern Appalachians around daybreak Friday, where PoPs will ramp back up to likely before 12Z. Most of the deeper moisture along the frontal zone trails the cold front, and QPF is expected to diminish as the system transits the mountains Friday morning. Will thus diminish PoPs quickly east of the mountains with the fropa. Cannot rule out some weak pockets of instability in the lower Piedmont with a midday fropa, but chances of convection appear very limited. The fropa should be delayed long enough for plenty of low to mid 70s temperatures to occur east of the mountains Friday. Falling heights upstream over the plains will then work quickly to reactivate upglide moisture over the stalling frontal zone, with light precipitation possibly returning to the southern Appalachians by Saturday. At the very least, returning clouds should cap maximum temperatures below climo. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 200 pm EST Wednesday: Confidence is fairly low on the PoPs, QPF, and potential wintry mountain ptypes for the latter half of the upcoming weekend. The GFS remains faster and more aggressive on the moisture return along the activating front, with the best deep moisture and QPF slated for primarily Saturday night through Sunday. The ECMWF delays the better QPF until Sunday. Neither solution is particularly cold, with just the higher ridges of NC mountains seeing much of a snow chance as the moisture returns. The Canadian remains the driest solution, with the stalled frontal boundary suppressed farther south, and ensemble members are quite varied. Will thus leave late weekend PoPs capped in the solid chance range for now. The ECMWF continues to feature low pressure development over the coastal waters on Monday, but it has trended weaker and farther southeast. The GFS has much less development and is drier, so a dry forecast is maintained either way for Monday. Dry high pressure will persist on Tuesday as a surface high slips off the East Coast. A backdoor cold front should move southward through the region on Wednesday, but any moisture looks quite sparse with this boundary. Temperatures will be near climo through the period. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... At KCLT and elsewhere: VFR for the most part through the evening hours, although MVFR lurks to the S/E of KCLT. Low clouds will expand/redevelop during the early morning hours as low level moist upglide starts to develop. As a result, a low cloud deck should grow rapidly, perhaps initially at the MVFR level, but will quickly drop to IFR/LIFR at most terminals before the start of operations Thursday morning. There is some debate about the coverage of light precip on Thursday morning, but the precip will be light rain/drizzle and of secondary importance to the low clouds and fog. Will use a TEMPO to describe the worst of conditions from daybreak through mid-morning, which should be LIFR at most terminals, but could be VLIFR at times. The development of light precip over the top of a developing wedge boundary will help to cool the air mass to the north of the region and drive this boundary southward in the afternoon, which will lock in the IFR conditions across the region. Outlook: A relatively active pattern will remain in place through the work week with associated flight restrictions. A lull is expected to develop Friday with conditions returning to VFR into early Saturday before another storm system enters the area with likely flight restrictions late Saturday into Sunday. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...Dense Fog Advisory until 8 AM EST Thursday for NCZ068>072-082. SC...Dense Fog Advisory until 8 AM EST Thursday for SCZ006>014-019. && $$ SYNOPSIS...DEO NEAR TERM...AP/PM SHORT TERM...HG LONG TERM...HG AVIATION...PM
National Weather Service Jackson KY
854 PM EST Wed Feb 23 2022 .UPDATE... Issued at 854 PM EST WED FEB 23 2022 Temperatures are running cooler across the area this evening, with lower 30s having penetrated west of I-75, along portions of the Mountain Parkway, and near the I-64 corridor. Light precipitation has also been making it further east than forecast, and despite some drier air to overcome, some of the highest resolution model guidance has been indicating a window of enough saturation up north to allow for a better chance of measurable precipitation. Consequently, this will allow for a little more in the way of freezing rain across the northwest portion of the area. Most of the guidance is running too warm, so have relied more on the HRRR idea, which keeps temperatures fairly steady through the night. This seems reasonable, as northeast flow is maintained in the lower levels through at least early Thursday. Warm ground temperatures will prevent any significant impacts; however, some light glazing will be possible on elevated surfaces. It is also possible that a few higher elevation bridges and overpasses could pick up some light glazing, allowing for a few slick spots. As such, have issued a Special Weather Statement mentioning these concerns, again, generally west of I-75 and through portions of the Mountain Parkway and near the I-64 corridor. Updates have been sent. && .SHORT TERM...(This evening through Thursday night) Issued at 529 PM EST WED FEB 23 2022 Despite strong arctic high pressure over the northern plains sending colder air into our region and ending significant precip, skies remained cloudy all day, with low level moisture trapped in the frontal inversion on the upwind side of the Appalachians. Radar also shows drizzle persisting. The drizzle may shrink toward the southeast this evening, but clouds will persist until the next system moves in. That next system is already underway to our west and southwest. A cold front is laid out from just east of the central Appalachians to the southern tip of TX. Flow off the gulf is overriding the shallow cold air mass in the Deep south and then getting picked up by flow aloft and riding northeast on isentropic lift on the east side of a large mid/upper level trough centered over the western CONUS. This has resulted in precip breaking out as far east as western KY late today. This precip will continue to develop eastward tonight, affecting at least our southern counties by morning, and then spreading north. If it reaches our northern counties soon enough (overnight or early Thursday), freezing rain could result, with temperatures there expected to be at or just below freezing at that time. However, there is a question of whether it gets there that early, and whether or not anything but elevated surfaces would manage to accumulate light ice. For that reason, at this time it does not look terribly significant, but it will need to be watched. The heart of this mid/upper level trough is ejecting to the east northeast and will support development of surface low pressure over the lower Mississippi Valley on Thursday, which will track/develop quickly north northeast to the region of western NY/PA by early Friday morning. This will bring the initial area of precip north through eastern KY during the day Thursday, with a break arriving from south to north during the course of the day. The system`s cold front then plows through from northwest to southeast during the night with another round of rain. There is a risk of hydro problems once again with this system. The greatest risk is in our southern and central counties where the heaviest rain fell in the last system, and where the heaviest totals are also expected out of this one. Another factor is the potential for weak instability and convection. For these reasons, a Flood Watch has been issued for all but the northern portion of the forecast area. The back edge of the main precip should be in southeast KY and heading southeast early Friday morning, .LONG TERM...(Friday through Wednesday) Issued at 234 PM EST WED FEB 23 2022 The start of the extended begins with the tail-end of a system that is expected to bring widespread precipitation. The associated cold front is progged to cross through the area early Friday afternoon but ongoing rain and maybe a few rumbles of thunder will be possible for early Friday morning. Temperatures are expected to drop behind the front due to CAA; however, daytime highs for Saturday are expected to recover back into the mid-40s. Models continue to hint at another system that is forecasted to skirt the area late Saturday night into early Sunday morning. In recent model runs, deterministic models have this system taking a more southerly track and missing the forecast area but opted to keep PoP across the southern zones. With the timing of the system, precipitation looks to be messy as snow changing to rain-snow, to all rain is possible before ejecting out of the area. Accumulations look to be minor if any accumulation at all. If they`re are any accumulations, it could happen on the highest terrain across the south. After the weekend system ejects, zonal flow remains over the area. This will keep seasonal temperatures and dry weather across the region. However, models begin to diverge on toward the end of the period with respect to another system that`s expected to impact the forecast area for Tuesday into Wednesday. Did opt for the drier solution in the forecast grids for this even as confidence is extremely low. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) ISSUED AT 854 PM EST WED FEB 23 2022 Mainly IFR or lower conditions will be the rule through the majority of the period, with the exception at KSYM, where MVFR conditions will be maintained through much of the forecast. Light precipitation will move in overnight from the west. Some light freezing will be possible mainly along and northwest of a line from KSYM to KSME, with some glazing possible on elevated surfaces. More sustained rainfall will move in from the southwest on Thursday, with temperatures warming above freezing. The rain could be heavy at times. Northeast winds of 5 to 8 kts will veer to the east and southeast by late Thursday. && .JKL WATCHES/WARNINGS/ADVISORIES... Flood Watch from midnight EST tonight through Friday morning for KYZ058-068-069-079-080-083>088-107>120. && $$ UPDATE...GEOGERIAN SHORT TERM...HAL LONG TERM...VORST AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
958 PM CST Wed Feb 23 2022 .UPDATE... Issued at 949 PM CST Wed Feb 23 2022 We have had a lot of debate this evening on putting a Winter Weather Advisory up for Thursday afternoon, with the HRRR and other CAMs showing the potential for a band of 3-4" of snow from roughly Eau Claire back to Waseca. However, we decided to remain headline free. The biggest reason is snowfall amounts this high are highly dependent on snow ratios being much greater than climatology (13:1). Though HRRR outputs over 3" of snow at EAU and ACQ, BUFKIT snow amounts using the Cobb technique are about an 1" lower. In fact, all BUFKIT soundings from south central MN into western WI are showing snow totals of just 1-2", indicating our snow ratios may be overly optimistic as much of our sounding is actually colder than the DGZ, with the strongest lift (per omega profiles) well above the DGZ. When this happens, you tend to get very fine crystals, with a snow ratio that often stays down in the 10-12:1 range. With HREF probabilities for 1" per hour snow rates at 0%, there`s just not enough support out there to change our going non headline stance. && .DISCUSSION...(This evening through Wednesday) Issued at 258 PM CST Wed Feb 23 2022 KEY MESSAGES: - 1 to 3 inches of snow is expected from the Twin Cities south and eastward Thursday. - Return towards average temperatures early next week. A mid level cloud deck is approaching the area this afternoon ahead of a surface low that will pass far to our south through tomorrow. Increasing cloud cover and light winds will allow us to only brush Wind Chill Advisory criteria for our far northwestern counties overnight, so have opted to hold off on any headlines. Even though we will be on the northern edge of the aforementioned system, sufficient mid level forcing coupled with a 500mb shortwave moving into the Dakotas by late Thursday morning will allow for some light snow to develop. The main challenge with this forecast is determining where a potential fgen band will set up and lead to increased snow totals. Snow ratios are another deciding factor in snow amounts. Nudged ratios up to 20:1 with a deep DGZ across southern Minnesota, but it`s possible they could end up being closer to 25:1. Overall, snowfall totals will range from 1 to 3 inches, with confidence quickly dropping off for higher amounts. It is worth noting that there has been a slight upward trend in QPF/snow totals and this could end up being a low end Winter Weather Advisory event, but have decided to hold off for now. Snow will continue from early Thursday afternoon until eventually tapering off overnight. The remainder of the period will be dry with below normal temperatures continuing through the end of the week. We`ll see highs near average Saturday before a brief dip Sunday with a signal for warmer temperatures on the horizon as we head into March. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 526 PM CST Wed Feb 23 2022 Expect snow to overspread all MPX terminals, with the northwest edge of a broad snow shield expected to get all the way up to AXN in the afternoon. A burst of heavier snow, with visibilities as low as 1/2sm may impact RWF/MKT/MSP/RNH/EAU. We`ve seen a slowing trend with recent models for snow onset. Spread for snow onset is about 2 hours and have onset timing close to what the HRRR has. Winds will be light and variable overnight, becoming northeasterly Thursday, though with speeds under 10 kts. KMSP...Did slow snow onset some, with the RAP/GFS/NAM all showing snow starting after 18z, with a slowing trend noted in the GFSlamp as well. Expect snow to start between 16z and 19z. Between 19z and 23z, we could see some periods with a vis down to 1/2sm in snow, but left that potential out for now this far out with confidence in that occurring not high enough. /OUTLOOK FOR KMSP/ Fri...Mrng MVFR cigs, bcmg VFR. Wind WSW 5-10 kts. Sat...VFR. Wind SW 10G25 kts. Sun...VFR. Wind N 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ UPDATE...MPG DISCUSSION...Dye AVIATION...MPG
Area Forecast Discussion
National Weather Service Nashville TN
555 PM CST Wed Feb 23 2022 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Went ahead and updated the forecast as temperatures particularly in the northwest were too warm by 5 or 6 degrees. HRRR seems to be handling the shallow cold air the best so temperatures were adjusted with more weight put toward the HRRR solution. Looking at model soundings, the northwest part of our area will likely see some sleet and freezing rain this evening with the onset of precipitation. Temperatures are expected to warm a couple degrees overnight in the northwest allowing all precipitation to switch to rain. It is possible that some vehicles and elevated surfaces could develop a glaze in the far northwest, otherwise, no accumulations or impacts are expected. As far as rainfall amounts with this wave of precipitation, 1-2 inches of rain is possible which could cause creeks and rivers to rise again given the saturated ground conditions and already swollen bodies of water. The flood watch goes in effect at 6 PM. && .AVIATION... 00Z TAF DISCUSSION. BNA/MQY/CKV/CSV...Middle Tennessee remains north of a surface trough extending out of the Gulf of Mexico. Temperatures therefore remain quite cold across the mid state owing to a persistent north wind, and low stratus and fog have stuck around a good part of the day. An area of precipitation is currently making its way across the Tennessee River, and some of this precipitation is going to start off as freezing or frozen, especially at CKV. Temperatures will gradually warm overnight as the aforementioned surface boundary lifts northward and focuses the most intense precipitation band across northern Middle Tennessee. So look for rain to settle in this evening and continue throughout Thursday with persistent IFR/LIFR ceilings. && .OHX WATCHES/WARNINGS/ADVISORIES... Flood Watch through late Thursday night for Cannon-Cheatham-Clay- Cumberland-Davidson-De Kalb-Dickson-Fentress-Hickman-Houston- Humphreys-Jackson-Lewis-Macon-Maury-Montgomery-Overton-Perry- Pickett-Putnam-Robertson-Rutherford-Smith-Stewart-Sumner- Trousdale-Wayne-White-Williamson-Wilson. && $$ DISCUSSION......Reagan AVIATION........08
Area Forecast Discussion
National Weather Service Phoenix AZ
524 PM MST Wed Feb 23 2022 .UPDATE...Updated Aviation Discussion. && .SYNOPSIS... A storm system moving across the area today will bring lower elevation rain, mountain snow, gusty winds, and well-below normal temperatures. More tranquil weather conditions are then expected beginning Thursday and continuing through the rest of the forecast period with temperatures gradually moderating. && .DISCUSSION... Latest water vapor imagery as well as objective analysis are now short the deep upper low center that is bringing a variety of weather conditions to our CWA is now moving across SE CA and is expected to move into NW AZ shortly. A 90 kt jet max at 500 mb is now moving in the southern AZ, with good mid-level diffluence ahead of the main low center across most of AZ. The associated sfc cold front has now moved into eastern Maricopa/NW Pinal counties. Along/just behind the sfc front, widespread rainfall has occurred over much of South-Central AZ with rainfall amounts in the 0.25=0.50 inch range being reported so far. Lesser rainfall amounts have been reported across SW AZ/SE CA, mainly 0.10 inch or less across SW AZ and 0.00-Trace across SE CA. latest 88-D radar output is currently showing the heaviest/steadiest rain now moving into southern Gila/NW Pinal/extreme eastern Maricopa counties with some showers still falling from central/western Maricopa county westward all the way thru SW AZ/SE CA. Along with the rainfall, much cooler air has spread across south-central AZ. Phoenix Sky Harbor fell from a temp of 56 degrees shortly after midnight down into the mid-40`s at this hour. Given the very cold airmass (850 mb temps around 0C on latest high-res guidance), snow levels are also quite low, with reports of flakes in the air at elevations as low as 2700 feet over far-north Scottsdale being reported. Further to the west, breaks in the clouds have allow temps to rise into the 50`s. As far as the short-term forecast is concerned, latest HRRR high- res model forecasts are indicating that the band of heaviest rain/snow will progress eastward across eastern AZ this evening, then into western NM late tonight. NBM QPF guidance is showing anywhere from 0.50 to 1.25 inch across southern Gila county this evening. Given the continued low snow levels (3000-4000 ft), confidence remains high that at least a few inches of snowfall will occur above 4000 feet, with amounts as high as 12 inches over the highest peaks. Given the low snow levels, runoff into area streams/washes should be kept in check, with the forecast for Tonto Creek nears Roosevelt now remaining below Action Stage. Further to the west, athough a gradual drying/clearing trend is expected to continue thru the rest of the afternoon/evening, some additional shower activity could occur that could add a few more hundredths of an inch to the buckets. There is still a slight chance that a isolated TS could occur as well (10-15%) thru the rest of the afternoon/early evening, given the still-unstable forecast soundings (150-250 J/kg of CAPE) and breaks in the cloud cover allowing temps to locally warm a bit. Any storms that do occur could briefly lower freezing levels, perhaps allowing a bit of small hail/graupel to reach the ground across the lower elevations of south-central AZ. Along with the hail/graupel, locally gusty winds could also occur, with speeds as high as 35 kts possible. AS far as the forecast is concerned for late tonight thru Friday, the much colder than normal daytime high temperatures will set the stage for a couple of very cold early mornings both Thursday and Friday. The combination of clear skies and light winds will cause temperatures to dip to around freezing across many of the rural communities, especially across La Paz County tonight/Thursday night and NW Pinal County on Thursday night. Across the Phoenix area, early morning temperatures in the middle to upper 30s are expected both days. A return to a more tranquil weather pattern is then expected as we head towards the end of the week and into the weekend. After the passage of the storm system today, heights aloft will be on rise during the next several days as a ridge over the eastern Pacific moves into the west coast. A shortwave trough will move across the intermountain west Friday into Saturday and remain northeast of the area. No impacts are expected from this system other than possibly some enhanced northerly breezes along the Lower Colorado River Valley, especially on Saturday, when wind gusts in excess of 20 mph are possible. By Sunday and continuing into most of next week, there is good agreement amongst the ensemble cluster analysis of ridging aloft taking hold across the western CONUS. As the heights aloft rise through the end of the week and into the upcoming weekend, temperatures will gradually rebound back to near normal levels with above normal readings likely through most of next week. In fact, NBM probabilities for temperatures of greater than 80 degrees for Phoenix is greater than 60% from Tuesday onwards, with the probabilities at greater than 80% for southeast California. && .AVIATION...Updated at 0010Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Rain showers, low CIGS, and reduced visibility remain the top aviation weather concerns early this evening. Bands of light to moderate showers, and areas of more isolated showers, will continue to move through the terminal area until approximately 01-03z this evening. A slight 15% chance of isolated showers (VCSH) will also linger until this evening at 06Z. Cigs will generally stay between 4-6 kft through early evening with temporary lower cigs between 2-3 kft during shower activity. Visibility will be reduced to 2-5 SM during showers depending on rain intensity. All of these conditions should improve fairly quickly after 01-02z this evening. Otherwise, W component winds will prevail while speeds decrease to AOB 7 kts this evening after 03-04Z. Early Thu mroning there is a ~20-35% chc of FEW low clouds forming at 1-2 hft and occasional limited vsby of 2-5 SM in developing patchy morning fog between 13-16Z. Otherwise there is uncertainty regarding wind directions and the timing of any shifts later tonight through early afternoon Thu, but speeds will be light by then AOB 6 kts with clear to mostly clear skies. Southeast California/Southwest Arizona including KIPL and KBLH: Showers in the vicinity and lingering low cloud CIGs AOB 6 kft will persist early this evening until about 03-04Z at the terminals. At KIPL, strong W winds with gusts of 15-30 kts will last until about 07Z tonight. At KBLH, very breezy W winds with gusts of 22-27 kts are also expected until 03-04Z. Slightly lower visibilities AOA 6 SM in patchy light fog is also probable for KIPL on Wed morning. Otherwise lighter winds and clear to mostly clear skies will take over. && .FIRE WEATHER... Friday through Tuesday: Below normal temperatures are expected on Friday, climbing to near normal on Saturday, and then above normal the rest of the period. A dry disturbance will result in enhanced breeziness late Friday into Saturday, with gusts in excess of 20 mph possible, mainly along the lower Colorado River Valley area. Otherwise, mainly light winds will prevail during the rest of the period. Min RH values will range between 10-20% with overnight RH values recovering to between 30-60% across eastern districts and between 20-35% across western districts. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Winter Weather Advisory until 11 PM MST this evening for AZZ545- 557-558-562-563. CA...None. && $$ Visit us on Facebook, Twitter, and at DISCUSSION...Percha/Lojero AVIATION...Sawtelle/12 FIRE WEATHER...Lojero
...Update to aviation forecast discussion...

.DISCUSSION... Issued at 222 PM CST Wed Feb 23 2022 Key messages: - Light wintry precipitation impacts the morning commute Thursday towards far eastern Kansas. - One final chilly afternoon Thursday before sun and warmer temps return this weekend into next week. Mid to high level clouds continue to stream across eastern Kansas this afternoon, as the associated midlevel clipper system translates into the Mississippi Valley. Reports of snow and sleet with this system are just to our south near Chanute as the precip shield lifts northeast into southern Missouri. This evening is cool and dry as the next southwesterly upper trough lifts into the central plains by Thursday morning. Similar to previous forecasts, models are consistent on the weak and narrow area of lift in the 600-700 mb layer that quickly moves east of the area by mid afternoon. Forecast soundings vary somewhat in the moisture availability, particularly in the dendritic growth layer over far eastern Kansas where light snow may mix with light freezing drizzle. The HRRR and RAP past runs are more pronounced with this scenario along and southeast of I-35 while consensus leans more towards a shallow and very cold profile below 700 mb, similar to Tuesday morning where snow was observed. Overall snow accumulations through Thursday afternoon are an inch or less, despite some ensemble members clustering close to 2 inches. After collaboration with surrounding offices, opted to hold off on an Advisory headline and will evaluate later this evening as this event has the potential to cause hazardous travel for the morning commute. One final day of lows in the teens and highs in the 20s Thursday before the upper pattern transitions to dry northwest flow aloft, signaling warming and dry conditions likely. Above freezing, downsloping air arrives in time for the weekend as highs warm from the 40s Saturday to upper 50s on Sunday. Similar pattern persists into next week allowing temps to peak in the middle 60s once again. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 530 PM CST Wed Feb 23 2022 High clouds are continuing to filter in from the southwest as a system off in northwest Arkansas moves eastward. VFR conditions will continue overnight but by Thursday morning, expect MVFR ceilings to move in around 14z as light snow will begin to fall at all terminals. This snow could limit visibilities a bit, but should stay MVFR at the worst. Snow showers will begin to end in the area by 4-5 pm with visibilities and ceilings raising back to VFR criteria. Winds should remain light around 10 knots or less throughout the TAF period. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...22 AVIATION...Griesemer