Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/29/22

Area Forecast Discussion
National Weather Service La Crosse WI
945 PM CST Wed Dec 28 2022 .DISCUSSION...(Tonight through Wednesday) Issued at 215 PM CST Wed Dec 28 2022 Key Messages: - Mild temps into the start of the new year - Drizzle, fog (wintry mix?) Thu into Thu night - Storm system on track to bring widespread precipitation starting Monday night. Model differences vary on strength and track, but trends favor mostly rain (as of now) locally. * MILD INTO NEW YEAR: amplified upper level ridge exits east Thu, with a trough swinging through later Thu/Fri, but then followed by more broad ridging for the weekend into the start of next week. NAEFS/ECMWF 850 mb temp anomalies +1 to +2 into Thu, falling off but mostly hovering from 0 to +1 into the early part of next week. GEFS/ECMWF ensemble means suggest a high likelihood to clear 40 across portion of northeast IA/southwest WI (80-100%) Thu, and then after a brief shot of cooler air for Fri, post the Thu system, the models suggest we stay at or above freezing (and above normal) for highs (60-80% chance) into the middle part of next week. Consistent signal. Thu may be tempered by clouds, fog and drizzle. All in all, an extended break from the very cold conditions of the last 10 days or so. * DRIZZLY/FOGGY DAY TOMORROW? FREEZING DRIZZLE POSSIBLE? An anomalously moist/mild airmass set to push northeast across the area tonight/Thu. The air will be riding over a few inches of snow pack, with melting helping to further moisten the boundary layer. RAP Tds push into the upper 30s for sfc Tds across NE IA/SW WI by Thu afternoon (model blend is higher). While another day or two would push the threat for widespread fog and/or stratus upward, CAMS and SREF guidance favor at least some fog development. Bufkit soundings show a healthy low level inversion to pool the saturation under. Whether there has been enough melting/time to develop widespread fog is in question. Will stick with patchy for now. With broad low level thermodynamics promising some (albeit weak) lift along the 280:290 K isentropic surfaces, will saturation be deep enough to produce drizzle? Northwest-southeast running x- sections and Bufkit soundings suggest the deeper low level saturation will likely hold from parts of of NE IA into southwest WI, more favorable by Thu afternoon. Elsewhere saturation appears too shallow. Don`t really get into a deeper column until well north/west - and ice is introduced into the cloud then. Will continue with drizzle chances for most of the day Thu. Moving into Thu evening, passage of a cold front will cause drop in temps but also some increase in the low level saturation (per Bufkit soundings) and provide some Fgen lift in its wake. This could be enough to produce some drizzle in the west, favoring freezing drizzle based on falling temps. Confidence not overly high, but enough of a threat to warrant inclusion in the forecast. As for any snow threat, models favor keeping this over central/northern MN where more of the column is saturated and the upper level trough can work on it. * STORM SYSTEM TO KICK OFF THE NEW YEAR: GFS/EC have been in good agreement with lifting a 500 mb trough from the desert southwest northeast Sunday night, developing a closed low as it slides over the upper mississippi river valley by Tue morning. Where it moves and how strong the system becomes is still up in the air. SPC cluster analysis continues to lean toward 2 possible outcomes - one stronger and more westward, with the second a bit weaker and faster. The bulk of the EC ensemble members remain more fixated on the quicker/weaker solution while the GFS members lean the other way. This has been a consistent signal over the past few days. That said, each model shows a lot of variability within their members too. Overall, confidence low in these details but remains high that pcpn WILL spread across the region from Monday night through Tue (potentially lingering longer). Also, confidence leans into most of what falls locally to be rain. The higher potential for accumulating snows holds west/northwest in each of the models, with only a 30-50% chance (currently) for at least an inch for locations north of I-94 and west of HWY 52 (southeast MN). All said, looks more wet than snowy at this time. The exit of the storm will also mark the end of the mild conditions, with colder (seasonable) air working in for the latter half of the week. Could also see another shot for pcpn (now mainly snow) toward the end of the new work week. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 945 PM CST Wed Dec 28 2022 The main forecast concern continues to be with low ceiling/fog potential on Thursday. Maintained similar trends to the previous issuance with a slight slowing in initial stratus development, but uncertainty in coverage/timing persists. There is the potential for IFR/LIFR visibilities as well where the moist airmass overspreads the deeper snowpack and winds are light between an advancing warm front to the south and another front to the west that will shift winds westerly by Thursday evening. Some drizzle is possible by afternoon with a small chance for freezing drizzle Thursday evening at KRST, but at this time, confidence in occurrence is low. Improving conditions are expected later Thursday night behind the front. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ DISCUSSION...Rieck AVIATION...JM
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
527 PM MST Wed Dec 28 2022 ...New AVIATION... .SYNOPSIS... Issued at 157 PM MST Wed Dec 28 2022 A storm system is bringing breezy to windy conditions, lowland rain showers and mountain snows across the Borderland through Friday morning. Warmer temperatures return Friday into the weekend with breezy afternoon winds continuing. Another storm system arrives on Sunday, with cooler temperatures and more snow chances for area mountains. && .SHORT TERM... (This evening through Thursday) Issued at 157 PM MST Wed Dec 28 2022 All eyes are on the strong Pacific storm system that has been traversing the Intermountain West and now impacting the forecast area. Current satellite imagery overlayed with 500mb RAP Analysis shows the large upper level trough across the western half of CONUS with the associated trough axis over UT/AZ approaching the Four Corners vicinity. Water vapor imagery shows a large fetch of moisture moving over the region originating from the southwest. Visible satellite imagery confirms the presence of moisture in the mid to upper levels with most of the region locked in under broken to overcast skies. In fact, radar imagery is picking up on some light precipitation now impacting the CWA, mainly over area mountains and west of the Continental Divide. This strong upper level system will continue to move and dig across the Desert Southwest as strong 250mb (120 knot) jet gains momentum this afternoon and propagates/phases over the region, situating over CO/NM vicinity. This will ultimately induce and lead to further development of a lee-side surface cyclone that`s currently over southwestern KS at 994mb. The dynamics aloft in combination with the further development of a surface pressure gradient will continue ramping up winds across the area. This dynamic storm system also poses the threat of winter weather. Precipitation chances will increase through the afternoon and evening, especially over area mountains above 7,000-7,500 feet, where a healthy amount of snow could fall. Snow could be heavy at times especially for Sierra Blanca Peak, CLoudcroft, Sunspot, and other locations along the ridgeline within the Sacs; Pinos altos and locations in the Black Range as well. THIS AFTERNOON - EARLY THURSDAY MORNING: WIND: A High Wind Warning remains in effect this afternoon, lasting through late this evening for the Gila Highlands/Mtns, Sacramento Mtns and adjacent east slopes, and the NM Bootheel Highlands. A Wind Advisory will remain in effect this afternoon, lasting through late this evening for the Black Range east slopes, lower elevations of NM Bootheel, and Otero Mesa/Hueco Mtns/ southeastern Otero County/northern half of Hudspeth County/southern Tularosa Basin. Winds will continue to increase across the forecast area through the afternoon and evening. We are currently seeing a wide range of winds across the area with most lowlands locations gusting anywhere between 25 to 40 mph and 45 to 55 in the Sacramento/San Andreas/Organs and even the Franklin Mtns. The Sacs will continue to see the highest wind gusts, possibly reaching 60 to 70 mph range. These strong of winds in combination with moderate to heavy snowfall over the mountains (discussed below), could lead to poor visibilities due to blowing/drifting snow. Additionally, trees and branches may become overloaded with heavy wet snow, leading to downed trees and possible damages to power lines in tandem with the strong winds. WINTER WEATHER: A Winter Storm Warning remains in effect through mid evening for the Gila Highlands/Mtns, and mid afternoon through the early morning on Thursday for the Sacramento Mtns (above 7,000-7,500 feet). Snow will ramp up, especially over the Sacs through the afternoon and evening hours. First starting out over 8,500-9,000 feet before dropping to 7,000-7,500 feet. Snow will become heavy at times with generally 4-8 inches expected for the Gila/Black Range this afternoon/evening and 6-10 inches over the Sacramento Mtns. With the west/southwest trajectory of winds, the west/southwest facing slopes should receive the heaviest totals. Snow will gradually taper off by the evening for the Gila and by midnight, or a few hours after for the Sacs. Snow and winds will gradually decrease through the late evening and into the overnight hours. By tomorrow, the trough axis associated with the storm system will pass through and move to the east, leaving the area under predominately a northwest flow regime on Thursday. This will likely keep most of the area under partly to mostly cloudy skies throughout the day with relatively mild temperatures. The continued development of lee-side surface low pressure over the central Great Plains will keep winds breezy, mainly out of the west. Lingering moisture on the backside of the trough could lead to isolated showers for areas along and west of the Continental Divide. && .LONG TERM... (Thursday night through next Tuesday) Issued at 157 PM MST Wed Dec 28 2022 Breezy to windy conditions will exist through the long term as a series of systems move across the U.S. and through the Borderland. This will leave the region with unsettled weather conditions, and reoccurring shots at mountain snow and lowland rain showers. Thursday night, the upper level trough axis will pass through the region. This will keep lowland rain shower and mountain snow chances going overnight. Snow levels drop down to about 6500-7000 feet in the Gila. However, all accumulations overnight on Thursday will be light as the system will exit to our east on Friday morning. Clouds will become partly cloudy to mostly clear as northwest flow takes over. This will leave the rest of Friday and Saturday with dry conditions and warming temperatures as zonal flow sets up ahead of the next system. If you are looking for a warm New Year`s Eve, this is your year -- lowland 60s/mountain 40s/50s. However, with zonal flow comes the increased pressure gradient and afternoon breezy to windy conditions through the weekend. The give and take of winter weather. On Sunday afternoon, the next upper level system arrives as a N/S orientated jet pushes a robust closed low across the Four Corners Region. This will place the Borderland in a favorable region for widespread rain chances, and for more mountain snow. Looks like some rain may fall before the changeover to snow in the mountain regions. Snow levels drop down to around 5000 feet through Monday. Looks like total snow for the mountains for Sunday/Monday`s system is an additional 3-6" (localized higher amounts possible), with lowland rain amounts 0.3" in the northwest to and 0.05" to the southeast. Behind this front is a stout cold front bringing breezy to windy conditions as it pushes through overnight Monday, leaving Monday`s highs below seasonal average. This system exits Monday night. On Tuesday morning, there is good agreement on the next system arriving as a shortwave move through once again, bringing much of the same- lowland rain showers and mountain snow chances. Highs will remain cool -- lowland 50s, mountain 20s/30s on Monday and Tuesday. && .AVIATION... (00Z TAFS) Issued at 346 PM MST Wed Dec 28 2022 Mostly VFR conditions expected through the period. Lower CIGS and VIS are possible, especially near areas of rain/snow showers. Best chances for SHRA/SHSN will be in areas east of the Rio Grande. Snow levels remain above 6500-7000 feet. Strong gusty winds continue this evening, but winds should be slowing during through the overnight period. Winds will be from the west with speeds 15 to 25 kts at TAF sites. Stronger winds continue in area mountains and over the east slopes of mountains. LLWS and turbulence possible in those same areas too overnight. Winds decrease overnight and into the morning hours, but breezy winds return in the afternoon. && .FIRE WEATHER... Issued at 157 PM MST Wed Dec 28 2022 Elevated fire weather concerns will be possible for the remainder of this afternoon and into the early evening hours across far southeastern Hudspeth County. Dry Min RHs of 13-18% are being observed, along with winds of 20-30 mph. However, RH value will rebound as moisture moves in from the west right around sunset. A series of storm systems will move off the Pacific and across region over the next 5 days with periods of rain/snow. Each day will also be breezy to windy; fortunately min RHs will be well above elevated levels between 30-70% across all fire weather zones. For tomorrow, a few showers and mountain snow showers possible again before conditions dry out Friday and Saturday. Rain and snow likely again Sunday and Monday with occasional heavy snow possible over the mountains. As mentioned previously, breezy to windy each day, with the strongest winds today, and to a bit lesser degree, on Sunday. Vent rates will be good/very good today, fair/good Thursday through Saturday, then very good/excellent Sunday/Monday. && .PRELIMINARY POINT TEMPS/POPS... El Paso 41 58 39 59 / 10 10 20 0 Sierra Blanca 37 53 36 53 / 10 10 20 0 Las Cruces 35 55 33 56 / 10 0 10 0 Alamogordo 32 54 30 54 / 30 0 10 0 Cloudcroft 23 33 22 34 / 80 0 10 0 Truth or Consequences 32 53 31 54 / 10 10 10 0 Silver City 34 46 33 46 / 40 10 20 10 Deming 34 55 32 55 / 10 10 20 0 Lordsburg 33 53 34 54 / 20 20 30 0 West El Paso Metro 38 57 38 58 / 10 10 20 0 Dell City 36 58 34 58 / 10 0 10 0 Fort Hancock 37 59 37 59 / 10 10 20 0 Loma Linda 36 51 35 51 / 10 0 20 0 Fabens 37 58 37 59 / 10 10 20 0 Santa Teresa 35 56 34 57 / 10 10 20 0 White Sands HQ 39 56 37 57 / 10 0 10 0 Jornada Range 35 53 33 55 / 10 0 10 0 Hatch 34 56 31 57 / 10 0 10 0 Columbus 36 56 35 57 / 10 10 20 0 Orogrande 35 56 33 56 / 10 0 10 0 Mayhill 29 46 27 47 / 40 0 10 0 Mescalero 27 43 25 44 / 70 0 10 0 Timberon 25 43 24 43 / 60 0 10 0 Winston 30 48 28 50 / 10 10 10 0 Hillsboro 31 53 29 55 / 10 10 10 0 Spaceport 32 53 30 55 / 10 10 10 0 Lake Roberts 27 45 25 45 / 30 20 20 10 Hurley 34 52 31 52 / 30 10 20 0 Cliff 26 53 25 53 / 40 20 20 10 Mule Creek 32 47 32 46 / 40 20 20 10 Faywood 34 51 32 51 / 30 10 20 0 Animas 33 54 33 56 / 20 20 30 0 Hachita 33 54 32 56 / 10 10 20 0 Antelope Wells 35 53 33 55 / 10 20 30 0 Cloverdale 36 46 35 50 / 40 30 30 0 && .EPZ WATCHES/WARNINGS/ADVISORIES... TX...Wind Advisory until 11 PM MST this evening for TXZ420-421. NM...High Wind Warning until 11 PM MST this evening for NMZ402-406- 414>416. Winter Storm Warning until 8 PM MST this evening for NMZ402. Wind Advisory until 11 PM MST this evening for NMZ405-408-413- 417. Winter Storm Warning until 2 AM MST Thursday for NMZ415. && $$ SHORT TERM...38-Rogers LONG TERM....33-Reynolds AVIATION...29-Crespo
Area Forecast Discussion
National Weather Service North Platte NE
534 PM CST Wed Dec 28 2022 .SYNOPSIS... Issued at 359 PM CST Wed Dec 28 2022 The models are now spotlighting a vigorous upper level disturbance moving through wrn UT this afternoon for significant snow across swrn and parts of ncntl Nebraska late tonight and Thursday morning. Key Messages: -Forecast updates may be needed for this event and those updates, if needed, would most likely occur late this evening or early Thursday morning. For now the forecast is for rain changing to 1 to 3 inches of snow. -A winter storm appears likely to affect wrn and ncntl Nebraska Sunday night through Monday night. WPC has increased their winter storm probability to likely across nrn Nebraska, generally from KVTN west to KIEN. It is this area that is the most likely area for heavy snowfall. && .SHORT TERM...(This evening through Thursday night) Issued at 359 PM CST Wed Dec 28 2022 The models are now spotlighting a vigorous upper level disturbance moving through wrn UT this afternoon for significant snow across swrn and parts of ncntl Nebraska late tonight and Thursday morning. How vigorous? The 18z NAM and 19z and 20Z RAP lift in the DGZ and resulting QPF could generate a snowfall rate near 2 inches per hour along and just left of a line from near KMCK to KLXN and KORD. This is just west of a rain snow line predicted to develop by the models. A few models show a closed h700mb low across swrn Nebraska 12z Thursday and this disturbance should track northeast into nern Nebraska by early afternoon. The RAP now shows a well pronounced PV1.5 anomaly leading the precip shield. The models are either playing catch up or crying wolf, ghosting significant snowfall. In fact, it will still be raining across swrn Nebraska at 3 am Thursday morning. It is worth noting the 15z SREF has perked back up suggesting a 30 percent chance of 4 inches or greater snowfall. Forecast updates may be needed for this event and those updates, if needed, would most likely occur late this evening or early Thursday morning. For now the forecast is for rain changing to 1 to 3 inches of snow. The forecast uses the 12z model QPF blend which for this event has increased to around 0.66 inches centered along a KMCK-KLXN- KORD line. About half of this will fall as rain. Note, the 18z blend suggested amounts closer to 0.80 inches. .LONG TERM...(Friday through Wednesday) Issued at 359 PM CST Wed Dec 28 2022 Attention turns to the significant storm predicted to affect wrn and ncntl Nebraska Sunday night through Monday night. A blend of the GEM, GFS, ECM ensembles plus the deterministic Icosahedral model from Germany suggests a snowfall location across wrn and ncntl Nebraska, stretching from KOGA north to KVTN including areas north and west into SD. WPC has increased their winter storm probability to likely across nrn Nebraska, generally from KVTN west to KIEN. It is this area that is the most likely area for heavy snowfall. The deterministic models continue struggle with the storm track, but consistent in the sense the GFS is the farther northwest favoring northwest Neb and SD for heavy snow while the operational ECM generally favors wrn and ncntl Nebraska. The icosahedral is in between while the GEM is northwest of the GFS favoring just SD for heavy snow. The WPC QPF suggested a blend of the GFS ensemble and ECM operational for this system. It is important to remember the storm track could easily vary by 100 to 200 miles. The storm is still across nrn Japan. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 533 PM CST Wed Dec 28 2022 Precipitation will arrive tonight starting off as all rain before transitioning over to a rain/snow mix. Snow may briefly change over to all snow around sunrise with rapid reductions in visibility as snowfall rates approach 1 to 2 inches per hour. All precipitation will stay well south of KVTN with the only impact here being some lowering ceilings below 3000 feet Thursday morning. Precipitation ends by the afternoon with ceilings gradually rising but remaining overcast through the afternoon. && .LBF WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from midnight CST /11 PM MST/ tonight to noon CST /11 AM MST/ Thursday for NEZ028-029-038-058-059-069>071. && $$ SYNOPSIS...CDC SHORT TERM...CDC LONG TERM...CDC AVIATION...Kulik
However, as the morning forecast discussion alluded to, this
drizzle/fog scenario would likely only come to fruition in the event
that we were able to maintain some semblance of a snowpack, and for most, if not all, locations across our CWA, that will not turn out to be the case. Although it`s still conceivable that the inbound low- level moisture surge ends up being sufficient on its own to develop drizzle and/or fog, with the lack of snow on the ground and with omega in the boundary layer not looking all that spectacular, think the potential for drizzle is looking rather low at this point, so have trended the "chance" drizzle mention to a "slight chance" mention for now. That said, considering that almost all guidance that squeezes drizzle out over our CWA tomorrow is inaccurately modeling a snowpack that is no longer there, there`s certainly an argument for removing the drizzle mention from the forecast altogether. Instead, think that we`ll be left with a stratus deck that may hang around for most of the day before potentially clearing out to some extent during the afternoon. While this deck may stunt solar insolation to some degree, the HRRR (which is handling the snowmelt the best out of all available guidance and most closely resembles our overall forecast thinking) is actually advertising 60 degree highs across our southwestern CWA tomorrow afternoon with mid-upper 50s elsewhere. Have not completely gone "all in" on this warmer solution given that we`re not completely discounting the scenario that we may see drizzle or fog, but did continue to hedge our forecast high temperatures in that direction given the decreasing confidence in drizzle/fog occurring. Aside from the drizzle potential tomorrow morning and afternoon, there also remains a chance for more bonafide rain showers Thursday night along an incoming cold front. Forecast soundings indicate that the front will initially intercept relatively dry air as it enters our western counties Thursday evening, and therefore, it would appear that this frontal passage may be a dry one for areas along and west of the I-39 corridor if this did indeed end up being the case. However, the front will encounter increasing moisture with eastward extent, where there will be a little more time to advect in some richer low/mid-level theta-e air. Accordingly, precipitation chances in our going forecast increase with eastward extent, with best chances to see precipitation in our CWA Thursday night looking to be in locations along and east of I-55. That being said, this probably won`t amount to anything more than a narrow line of showers forced along the cold front, so QPF is appropriately low. There is also a non- zero chance for thunder with this activity with mid-level lapse rates likely to be quite steep ahead of the front, but confidence in this occurring is presently too low to warrant a formal mention of thunder in the current forecast. Ogorek && .LONG TERM... Issued at 325 PM CST Wed Dec 28 2022 Friday through Wednesday... Key Forecast Message and Concerns: * Little/no threat for impactful wintry precipitation * Isolated thunderstorms possible Monday night-early Tuesday * Windy conditions likely on Tuesday The mild pattern will continue through mid next week. In the wake of the weak cold front passage Thursday night into Friday, the front will become stationary from downstate Illinois across central to northeast Indiana. Weak surface troughing will develop along the stationary front Friday night into Saturday. Most areas, with possible exception of southeast 1/3 or 1/4 of CWA should be dry Friday morning. Given likely lingering stratus and time of year, there won`t be much of a temperature change following the cold front passage through most of Friday, with only a gradual drop mid afternoon through sunset. From Friday afternoon into Saturday, deeper column moisture will expand back north and westward some. A series of sheared mid-level waves interacting with the stationary frontal zone (with some associated low and mid-level frontogenesis) and aided by upper jet dynamics should produce banded light to perhaps moderate rain, likely with a sharp cutoff on the northwest periphery of the precip. shield. While it could be close air temperature wise near the northwest fringe, with the mild antecedent conditions and most guidance pairing any measurable precip with temps above freezing, continued to keep out any freezing rain mention. Areas that stay dry may dip to or a few degrees below freezing by early Saturday. A surface low center is expected to evolve and slightly deepen out of the frontal trough on Saturday-Saturday evening. Most of the guidance continues to show a sharp precip. shield cutoff. Carrying low PoPs given uncertainty, though the non Canadian operational consensus would necessitate refining and sharpening up those PoPs. Saturday is again likely to exhibit a minimal diurnal range for afternoon high temperatures, and quite possibly less of one than in the official gridded forecast. Sunday will then be quiet and seasonably mild with forecast highs in the mid 40s for most locations. All in all, a mild New Year`s Eve-New Year`s Day stretch, though stay tuned for updates on the rain potential. The next stronger weather system to affect the area will likely be in the Monday PM-Tuesday timeframe. There is as to be expected variance in how the pattern evolves though decent agreement in the big picture idea of a low pressure tracking to our northwest sometime later Monday-Tuesday. How quickly the surface low ejects northeast will determine how long a sharpening warm front gets held south on Monday (with a large spread in the temperature outcome as a result). Temperatures are likely to rise Monday night as the warm front by then will likely be surging north, with well into 50s if not 60 a plausible scenario by Monday morning. Precip. wise, already enough confidence to support the categorical PoPs Monday night, with uncertainty on the onset of appreciable rain/showers Monday PM tied to the aforementioned low pressure track and timing uncertainty. Strong warm advection pattern is supportive of isolated embedded thunderstorm potential, with mention in the grids currently south of I-80. In addition, given far above normal PWATs (as much as 300-350% of normal), will need to watch for heavy rainfall rates and hydro issues as we`ve been noting in previous AFDs. Ahead of the trailing cold front on Tuesday, even in the slower solutions, expect a very mild start to Tuesday with mid- day/early afternoon highs well into the 50s, even upper 50s in spots. Held onto rain chances in the morning, followed by slight chance/spotty showers PM. Tight pressure gradient and then cold advection Tuesday PM will yield gusty southwest winds (up to 35 mph to ~40 mph on the high end). Next Wednesday will be noticeably cooler in the 30s for highs for most, though still above normal for early January. Currently showing a dry forecast, however note that depending on mid-upper low pressure trajectory, there may end up being a threat for light snow or snow showers in portions of the area. Castro && .AVIATION... For the 00Z TAFs... As a surface low pressure system develops in the central Plains tonight and lifts toward eastern Iowa tomorrow, increasing warm- air advection across the Mississippi River Valley atop a moistening boundary layer will encourage the development and maintenance of widespread stratus. Recent high resolution model guidance has slowed with the onset of stratus, though a signal remains that all terminals will be overcast by daybreak and remain as such through the remainder of the TAF period. Cloud bases should prevail between 1000 and 1300 feet from daybreak onward, with a signal in IFR // 700-900 feet // prevalent from mid-morning to mid-afternoon. For these reasons, will convert the inherited PROB30 for IFR cigs into a FM group. The signal for drizzle continues to lower, so opted to withhold any mention of visibility restrictions for now. Southwesterly winds will remain gusty (25-30kt) through the entire TAF period thanks to a strong and persistent low-level pressure gradient. A period of southwesterly LLWS is expected through the first 12-15 hours of the TAF period thanks to a stout 55-60kt southwesterly LLJ and at least some degree of static stability at the ground to prevent gusts from exceeding 30 kt. Borchardt && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Gale Warning...nearshore waters until midnight Thursday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Norman OK
528 PM CST Wed Dec 28 2022 ...New AVIATION... .UPDATE... Issued at 1251 PM CST Wed Dec 28 2022 RH values were running significantly lower than forecast across far western Oklahoma into parts of northwest Oklahoma. Updated our forecast using the HRRR and RAP which seem to capture this very localized dip in humidity. This does bump RFTIs into the critical range for small area, but only very briefly. Day && .SHORT TERM... (This evening through Thursday) Issued at 335 PM CST Wed Dec 28 2022 Through Tonight: Gusty southwest winds and elevated fire weather conditions remain the primary concerns. Despite scattered high cloud cover, vertical mixing/momentum transfer of 30-40 knot low-level (925-850 mb) flow, along with a compact pressure gradient, have fostered 40-50 mph wind gusts across western/central Oklahoma this afternoon. Wind gusts in the aforementioned range remain possible through around sunset in the area bounded by the I-40 corridor (where the strongest flow/tightest pressure gradient exists). While a Wind Advisory is in effect through 6 PM this evening, short-term trends will be monitored for a possible extension (in time) across eastern portions of the advisory area. While the 925-850 mb flow is expected to remain strong (30-40 knots), a nocturnally transitioning boundary layer, and weakening pressure gradient (as trough departs the region), introduce uncertainty in the need for a temporal extension. Elevated fire weather concern continues across northwest Oklahoma through sunset. The combination of gusty winds and a warm/dry downslope airmass (RH values <20%) have created favorable conditions for fire spread. Fortunately, the background fuel/ERC environment precludes a more widespread/high-end threat, though fire prevention practices should continue to be exercised across northwest Oklahoma through early this evening. Owing to the advection of a downslope-warmed air mass, near- record warmth (upper-60s to mid-70s) is being observed across much of the area along and west of I-35, with temperatures running 15-20 degrees above seasonal average. Quiet conditions are expected overnight, with a cold front beginning to impinge across northwest Oklahoma be early Thursday morning. Coldest overnight low temperatures (upper-30s) will be noted in this area, with mid-40s expected elsewhere. Thursday: Sensible weather impact is expected to be low, as a cold front slides southeastward across Oklahoma during daytime hours. The post-frontal regime is not expected to be highly modified such that above-normal high temperatures are expected across all zones. Afternoon temperature readings ranging from the mid-50s across northern Oklahoma to mid-60s across southern Oklahoma are forecast. Ungar && .LONG TERM... (Thursday night through next Tuesday) Issued at 335 PM CST Wed Dec 28 2022 Friday-Sunday: Current expectation is for a multiday period of relatively low weather impact. While the upstream pattern will be characterized by a high amplitude trough across the Southwestern US, the ejection of this feature looks to occur across south Texas/Gulf Coast, such that local impacts look limited. The main message this period is likely to be the well above average (+15-25 degree) temperatures expected for most areas. Temperatures will be the warmest across the Red River Valley each day. Dry surface conditions are currently anticipated, though a few deterministic members capture the potential for light showers across the I-35 corridor on Saturday. For now, this appears to be a low-probability outcome, with weak support in probabilistic guidance. Monday: Chances for precipitation appear to increase by Monday, especially along and east of the I-35 corridor. Both deterministic and ensemble guidance appears to be converging towards a solution that depicts a potent shortwave trough sliding from the Desert Southwest towards the Plains on Monday. Differences in timing and trough amplitude introduce uncertainty in the expected period of precipitation and amounts, though forecasted totals are on the lighter side at this update. This system is expected to bring a stronger cold frontal passage through the area by early Tuesday. Middle of Next Week: Behind the early week system, a return to low- impact weather is currently expected. While temperatures may run cooler behind the aforementioned front, current indications are for continued near to slightly above normal temperatures by the middle of next week. Upper-level ridging across the Rockies and western Plains would favor mostly dry times across the area. Ungar && .AVIATION... (00Z TAFS) Issued at 526 PM CST Wed Dec 28 2022 No restrictions expected through the forecast period. Gusty southerly winds will continue with LLWS most terminals through 14-15Z with strong low level jet in place. Winds will shift to more westerly tomorrow afternoon and weaken somewhat, with a light northerly shift toward and after 00Z. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 49 62 35 55 / 0 0 0 0 Hobart OK 48 63 34 57 / 0 0 0 0 Wichita Falls TX 51 66 40 61 / 0 0 0 0 Gage OK 42 56 27 55 / 0 0 0 0 Ponca City OK 48 59 31 53 / 0 0 0 0 Durant OK 54 66 44 63 / 0 0 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Wind Advisory until 6 PM CST this evening for OKZ008>032. TX...None. && $$ SHORT TERM...34 LONG TERM....34 AVIATION...11