Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/07/23

Area Forecast Discussion
National Weather Service Binghamton NY
644 PM EST Mon Mar 6 2023 .SYNOPSIS... A clipper system will bring some accumulating snow overnight, grazing parts of the Southern Tier of New York, but mostly focused over northeastern Pennsylvania, where snow may be heavy at times late tonight. Northwest flow will bring colder and cloudier conditions to the region Tuesday, with widespread light lake effect snow showers. This pattern will linger through most of the week ahead. && .NEAR TERM /THROUGH TUESDAY/... 634 PM update... No significant changes made to the forecast at this time. The onset of the steady snow that is expected to move in this evening was delayed by about an hour as the very dry boundary layer moistens up with the onset of precipitation. The axis of heaviest snowfall was not changed, but the northern edge of the snowfall gradient was sharpened up along and just north of the NY/PA border. Also at this time, it appears the heaviest snowfall rates will occur between 10 PM and 3 AM...where rates could approach 1 to 1.5 inches per hour briefly. There is also a narrow window late tonight and early Tue morning over portions of central NY were clouds could scatter out for a couple hours, which could lead to a period of rapid raditional cooling and drop temperatures over the northern Catskills and southern Tug Hill into the mid to upper teens. The rest of the forecast remains on track. 315 PM Update... Surface ridge axis extends across central NY and NE PA this afternoon. This will cause a surface low presently over Illinois to divert to the SE after reaching PA, but not before producing a narrow band of snow that will graze the southern portion of our CWA overnight. Models have come into better agreement on the track of the surface low and location of the heavier snow band. Precipitation already falling in southern lower Michigan will spread east into western NY/PA along and north of a band of low level frontogenesis and a low level deformation zone. Southerly winds at 850 mb look to briefly enhance late this evening over central PA, likely keeping the highest snow totals just to the west of our CWA. Most models, including most HREF members and subsequent HRRR runs, bring liquid QPF amounts of 0.50 to 0.75 inches into the far SW corner of Steuben County NY, then across Luzerne County PA, and quickly tapering off to less than 0.10 inches just to the north (e.g., southern Susquehanna County). The northern extent will be limited by a pronounced dry slot in the 900-800 mb layer. BUFKIT soundings show this holds together fairly well overnight north of the PA line. Temperatures in the Wyoming Valley have climbed up to the mid-40s this afternoon, but dewpoints remain in the low to mid-20s, and there`s the dry layer just aloft as well. This should allow precip to start off as rain but quickly change over to snow, though snow-to-liquid ratios look to stay around 7-8:1 over the area with highest QPF. Bottom line, expect a narrow strip of 3 to 5 inches across Luzerne County, with the lower amounts in the valley, and higher amounts in the mountains on either side. A few isolated 6 inch amounts are not out of the question, particularly in western Luzerne County, but the bulk of the area, including the more populated regions, should stay inside Advisory criteria. Another consideration is the timing -- heaviest snowfall rates of 1 to 2 inches per hour will only last for an hour or two, and all the snowfall will occur well after the evening commute, and several hours before the morning commute, reducing impacts. In the wake of this system, gusty NW winds will transport colder air into the region, and begin setting up widespread light lake effect clouds and snow showers. A shortwave trough dropping in from the north will cause an uptick in snowfall rates Tuesday night as 850 temps drop to -14 to -16C. Some areas may see 2 to 3 inches of snow from late Tuesday morning through late Tuesday night, mainly around the eastern Finger Lakes. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... 330 PM Forecast... High pressure centered over central Canada will extend into the eastern Great Lakes region, brining NW flow and a cold airmass to the region. 850mb temps will warm up to -6C during the morning hours. This is not an ideal temperature difference between Lake Ontario and this surface, but bufkit soundings show enough low level moisture to produce light snow showers. Scattered light lake effect snow showers and flurries are expected to be present through the period with the Finger Lakes having the best chance for continual scattered showers. Temps on Wednesday will be in the mid 20s to low 30s across NY with mid 30s in NEPA. Thursday will see a slight warming to temps in the low 30s to low 40s across the region. && .LONG TERM /FRIDAY THROUGH MONDAY/... 330 PM Forecast... The main concern for this period will be the development of the next winter system to impact the region Friday night into Saturday. After a hodgepodge of model solutions for this system over the past few days, guidance is starting to come together on the initial development of this system over the midwest. A shortwave is modeled to develop over the upper Midwest Friday morning and move to the ESE. After this initial shortwave development, model solutions diverge. Not as greatly as before but certain features develop within the models that either allow the storm to impact our region or send it south of the CWA. First is the location of the high pressure system over central Canada, and how it moves with the shortwave. Second is the strength of the shortwave and where the surface low develops. The GFS develops a much stronger shortwave earlier in the period with no high pressure blocking to the north. This allows the surface low to deepen and move ENE into our CWA starting Friday night and leaving on Saturday. The Euro is much weaker with the shortwave and keeps a strong ridge north of the low as it progresses eastward. This keeps the surface low much weaker and pushes the system to the ESE as it enters the Great Lakes, mostly missing the CWA to the south. The ensemble guidance for each of these models generally match up with the deterministic solutions so it at this point, it is hard to see which solution will be more accurate. Both develop a secondary low off the NJ coast, which if developed quickly and its eastward progression isn`t too fast, our SE counties could get a secondary blast of snow Saturday afternoon. For this forecast, the NBM was used as a starting point with PoPs capped to chance after Saturday morning given the high variability in the model solutions after this period. This gives us a mix of rain and snow through the period. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... All sites are currently VFR. However, a narrow band of snow over western NY and central PA is drifting east. While rain or mix will be possible prior to 03z at AVP, snow is expected to begin around 03z. With it, visibilities will be reduced while snow is present with restrictions falling into the LIFR category for a few hours. Snow may linger through much of the early morning hours, but should be over by sunrise. ELM may also get clipped by these snow showers this evening. Confidence was lower that there will be restrictions there, so a tempo group was added for a few hours. If this band of snow drifts further east than expected, then BGM could also observed snow showers, but confidence was too low to include snow in the TAFs. Lake effect clouds will move in Tuesday morning, bringing MVFR restrictions to all NY terminals, except ELM. These restrictions are expected to last through the rest of the TAF period. Snow showers are possible at SYR tomorrow evening. ITH and RME could also see a brief snow shower, but confidence was too low to include at this time. Visibilities may drop if a band is right over a terminal. Winds are calm for now, but become gusty after 06z. North to northwesterly winds will be as high as 15 to 20 kts with gusts of 25 to 30 kts, starting during the mid-morning hours and lasting through the early evening hours. Outlook... Tuesday Night through Thursday...Restrictions possible with lake effect snow showers; mainly Central NY sites. Friday...Mainly VFR under high pressure. Saturday...Restrictions possible with rain, snow, or both as a coastal low may develop. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Winter Weather Advisory until 7 AM EST Tuesday for PAZ038-043- 044-047. NY...None. && $$ SYNOPSIS...MPH NEAR TERM...BJT/MPH SHORT TERM...JTC LONG TERM...JTC AVIATION...BTL
Area Forecast Discussion
National Weather Service Boston/Norton MA
1011 PM EST Mon Mar 6 2023 .SYNOPSIS... Dry and quiet weather tonight through early Tuesday as low pressure tracks well south of our region. The dry/quiet trend continues as we head mid to late in the week, but it will be blustery at times. Could have some ocean effect rain/snow showers across the Cape/Islands Wednesday and late Thursday. Temperatures will be near seasonable. Lots of uncertainty for this coming weekend as low pressure tracks near/south of New England. This could bring us our next shot for wintry weather. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 1000 PM Update: Forecast in general looks on track with dry weather but with an increasing covg of mid to high clouds associated with a passing weak frontal system through the northern mid-Atlc states. Only the 18z GFS and the 00z FV3-WRF show any QPF into parts of Hartford County but given air mass both at sfc but through 800 mb as well is quite dry, dry weather to prevail despite the appearance on radar. All that said, the challenge will be on low temps given the increasing mid/high clouds, northerly mixed winds but also CAA occurring on the same north winds. Temps were already several degrees warmer than prior expectations and used a mix of the bias-corrected RGEM and bias-corrected HRRR datasets into the forecast to continue to slow cooling some through the balance of the overnight. Winds will be a bit stronger across eastern/northern areas, and less across western MA/western- northern CT where the potential for some decoupling exists. Thus warmer lows by a few degrees into the upper 20s to the mid 30s, tending colder to the north and west. Highlights... * Gusts continue though gusts are diminishing. * Dry with increasing clouds as a weak low pressure system tracks to the southwest of southern New England. Hope you were able to enjoy some of todays mild temperatures and the abundant sunshine! Afternoon maximum temperatures topped out between the upper-40s to the low-50s. Gusts this afternoon were generally between 25 to 35 knots, those gusts do ease overnight. Guidance remains in good agreement the surface ridge to our west breakdown and the pressure gradient relaxes. Still there is good low level mixing, should be able to mix up to 950mb, northwest gust between 15 and 25 knots are likely. As it is expecting to be gusty do not expect a night of radiational cooling. Seasonable overnight lows are expected in the middle and upper-20s. Dry conditions continue tonight, guidance keeps the track of a weak surface low southwest and impacting the NYC area. For our area, just clouds and a LOW chance for a flurry across southwest Connecticut. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Highlights... Tuesday... Any morning sunshine will be short-lived, increasing clouds by mid- morning as multiple shortwaves pivot around an area of low pressure east of New England. PWATs are greatest from Cape Ann and south to Cape Cod and Islands at 0.4 inch, could lead to isolated rain or snow shower. Otherwise, the daylight hours are dry with an abundance of cloud cover. Temperatures aloft are not much colder than it was on Monday, but given the added clouds it will be noticeably cooler as afternoon temperatures reach the upper-30s to low-40s. Winds start to pick up again with a LLJ with winds 30 to 40 knots, leading to a gusty afternoon as NNW to N winds gust between 20 and 30 knots. Tuesday Night... Dry with clouds. Southern New England is under a broad area of cyclonic flow, north to northwest winds remain gusty too. This pattern allows for a fairly seasonable night temperature wise, lows fall into the low and middle 20s. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights * Generally dry and quiet weather across the region through Fri with near seasonable temps. May be a bit breezy at times on Wed/Thu. * Lots of uncertainty for this coming weekend as there could be impacts from a coastal system, but need to hone in on the exact track. Wednesday through Friday... Caught in cyclonic flow through much of this period. A cutoff will be rotating just to the east/northeast of Newfoundland through this period, while a ridge builds into the Great Lakes. The ridge axis moves into the eastern Great Lakes/New England by late Friday. Will be caught between a high nudging in from northern Canada and a deep low near Newfoundland through this period. Generally anticipating dry and quiet weather through the vast majority of this period across southern New England. The only exception is across the Cape/Islands where there will be opportunities for ocean effect rain/snow showers Wed and late Thu into early Fri. Did have to blend the forecast toward the latest GFS/ECMWF/GEM guidance as the NBM is not picking up on these precip chances. At this point looks like any precip will be light. Anticipate it will be a bit breezy through this timeframe due to the tightened pressure gradient between the incoming high and low near Newfoundland. Will have roughly 20-40 kts of northerly flow across southern New England on Wed at 925 hPa. Should not be too difficult to mix down as colder air advects in with 0 to -4 degree Celsius air overhead. Expect a similar airmass in place through Fri, but winds shift on Fri as the ridge axis builds in. Will see those gusty winds coming down on Thu and especially Fri as the pressure gradient relaxes with the high nudging in. Temps will be near seasonable with highs generally in the 40s. Lows ranging from the mid 20s to mid 30s. Saturday and Sunday... Confidence in the forecast lowers significantly during this timeframe. The ridge axis over our region breaks down or builds into Nova Scotia/Newfoundland. In response to this a trough digs from the Great Lakes into the Mid Atlantic/southern New England and offshore. At this point given the differences in the upper dynamics am uncertain on where a coastal low will track. This could potentially bring us impactful winter weather this weekend. Given the large spread amongst guidance have stuck with the NBM at this point in time which paints chances of precipitation through the weekend. Will note that both the EPS/GEPS guidance have trended further to the south, similar to their deterministic models, which would result in minimal if any impacts to southern New England. The GEFS continues to trend near the benchmark, while its deterministic guidance is further to the N/NW. If the GEFS is correct then there would be more in the way of winter impacts to southern New England through the weekend. On top of this thermal profiles are all over the place as the track of the system will be key to determining exact ptypes. There will be a blocking high in place, which could keep colder air locked into our area. Need to see how things continue to trend as the week progresses. If folks have travel plans they will want to stay tuned to the forecast. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. 00Z TAF Update Tonight...High confidence. VFR, dry, and NW winds 10 to 15 kts, gust to 20 to 30 kts. Tuesday...High confidence. VFR through the morning. Lowering cigs to MVFR through by early afternoon across eastern Massachusetts. Dry day, though a low chance for -RASN exists for the outer Cape. Wind remains gusty from the NW/N up to 20 kts. Tuesday Night...High confidence. Dry with a mix of VFR/MVFR. Winds NW/N between 15 and 20 kts, gusts to 30 kts. KBOS Terminal...High confidence. KBDL Terminal...High confidence. Outlook /Wednesday through Saturday/... Wednesday: Mainly VFR, with areas MVFR possible. Windy with gusts up to 30 kt. Wednesday Night through Thursday: Mainly VFR, with local MVFR possible. Breezy. Thursday Night through Friday: VFR. Breezy. Friday Night: Mainly VFR, with local MVFR possible. Breezy. Slight chance SN. Saturday: MVFR/IFR conditions possible. Windy with gusts up to 35 kt. Chance RA, chance SN. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight through Tuesday Night... A dry period tonight through Tuesday night, with a low probability for a shower for the waters east of Cape Cod during Tuesday afternoon. Winds and seas diminish this evening across the waters, bringing an end to current Gale Warnings and Small Craft Advisories for a brief period of time. Winds pick right back up Tuesday, followed by increasing seas. Likely will need to re-issue a Small Craft Advisory later today after current headlines expire. Outlook /Wednesday through Saturday/... Wednesday: Strong winds with gusts up to 30 kt. Rough seas up to 10 ft. Slight chance of rain showers. Wednesday Night: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Slight chance of rain showers. Thursday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Thursday Night: Winds less than 25 kt. Areas of rough seas. Slight chance of rain showers. Friday: Winds less than 25 kt. Local rough seas. Friday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain. Saturday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Seas up to 5 ft. Chance of rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 1 AM EST Tuesday for ANZ230>235-251- 256. Small Craft Advisory until 7 AM EST Tuesday for ANZ250-254-255. && $$ SYNOPSIS...BL/Gaucher/KP NEAR TERM...Loconto/Gaucher SHORT TERM...Gaucher LONG TERM...BL AVIATION...BL/Loconto/Gaucher/KP MARINE...BL/Loconto/Gaucher
Area Forecast Discussion
National Weather Service State College PA
1104 PM EST Mon Mar 6 2023 .SYNOPSIS... A strong but fast-moving low pressure area will zip directly over the Laurel Highlands tonight as it speeds eastward. This will lead to a heavy snowfall for the northern mountains this evening and early tonight, and mainly rain for the southern half of the state. High pressure builds in with a gusty wind Tuesday. Expect generally fair weather into Friday with the next mixed precipitation event slated to arrive Friday or Friday night. It will turn blustery and colder for the weekend. && .NEAR TERM /UNTIL 7 AM TUESDAY MORNING/... A fast-moving area of low pressure, located over southwest PA at 03Z, will track just south of the forecast area late this evening, then off of the Mid Atlantic coast early Tuesday morning. Strong warm advection at the nose of a 40kt low level jet, combined with a plume of +1 SD pwats, is producing an area precipitation late this evening over eastern Ohio into northern Pennsylvania, with a narrow band of heavy snow focused along a ribbon of low and mid level fgen forcing from KDUJ to KIPT. Current RAP guidance indicates that this area of enhanced frontogenesis will slide east-southeast late this evening, resulting in locally heavy snowfall over the N Mtns, roughly between KBFD-KIPT. Only minor changes have been made to the previous snow forecast by incorporating latest HRRR qpf. Still expect a narrow band of around 6 inches over the north central mountains, with markedly lower amounts south of there and less than an inch south of a KFIG-KUNV-KRDG line. SLR should generally be fairly low with model profiles indicating plenty of riming in the lower 3km with temps in the -2C to -5C range. Expect precipitation to taper off rapidly from west to east after 06Z, as shortwave and associated surface low pass east of the state. Will continue to maintain near 100 pct POPs overnight. However, HREF reflectivity stamps indicate precipitation should fall primarily in the form of rain showers over the southern counties, with diminishing POPs toward the southern border. Can`t even rule out a rumble of thunder over the Laurel Highlands with the passage of mid level shortwave around 06Z. A few upstream strikes have been noted and the latest RAP indicate some minimal cape in this area. && .SHORT TERM /7 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... A few lingering upslope snow showers over the Laurels around dawn should give way to clearing skies, as strong subsidence overspreads the region behind the departing shortwave Tuesday. A fairly tight pressure gradient should result in gusty northwest winds Tuesday. Bufkit soundings support gusts between 30-35kts by afternoon. There appears to be an opportunity to beat NBM dewpoints Tuesday afternoon, with northwest flow and very dry air above a weak inversion signaling an afternoon dewpoint drop. The MixedDewpoint tool and MAV guidance are way lower than NBM dewpoints Tue afternoon, but have taken a conservative approach to remain in collaboration with neighbors. Mixing down 850mb temps of -5C to -8C yields expected highs from the low and mid 30s over the N tier, to the upper 40s across the Lower Susq Valley. A deep moisture on the western periphery of upper low off of the east coast is progged to edge into northern PA Tuesday night, supporting scattered orographic flurries/light snow showers, perhaps producing a dusting in spots. Otherwise, expect fair and continued blustery conditions. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Fair weather is expected for Wednesday into Thursday, as an upper level ridge builds eastward into the area. Wednesday will be a bit chillier than normal, with temperatures moderating to near normal by Thursday afternoon. For the end of the week, the focus will shift to a sharpening upper level trough that is expected to dig from the Great Lakes into the northern Mid Atlantic region and evolve into a cutoff low. The associated surface low is progged to track to the west of PA Friday into Fri night, drawing milder air overtop the chilly air in place at the surface, before a secondary low develops off the northern Mid Atlantic Coast. This points towards a potential wintry mix late Friday or Friday night. Odds favor chilly and unsettled conditions Saturday with scattered rain/snow showers accompanying the passage of the upper low. Generally fair and seasonable conditions look likely Sunday, as upper low lifts out. By Monday both the GEFS and ECENS show a deepening upper trough approaching from the Grt Lks with an associated coastal low passing too far east to affect central PA. The bulk of ensemble members point toward only scattered rain/snow showers associated with the trough passage Monday. However, a few indicate the associated coastal low will come close enough to PA to produce a more significant precip event. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... Low pressure will pass just S of KJST tonight, sliding along a warm front stretched from KPIT-KLWX. A long-lived band of (mainly) snow will cut thru the nrn mtns for 6-8hrs thru about 07Z. LIFR is expected at BFD and perhaps IPT later this evening and early tonight as the precip gets heavier there. UNV will be on the srn fringe of the moderate to heavy SN by around midnight. JST and will be south of the heaviest precip and may be rain for much of the night, but eventually gets cold enough for all snow by the end of the night. AOO will miss out on the bulk of the precip, getting some around or just after midnight, but not dipping to IFR for more than an hour or two. An hr or two of SN is poss at MDT and LNS, but only very late tonight. It should all be over with before sunrise, and probably around 08Z in UNV/AOO/IPT. The low pressure goes east fast, and the falling pressure and incoming high pressure will result in gusty WNW wind on Tuesday. Some upslope SHSN are expected for the wrn highlands as a small secondary wave drops across in the morning. Outlook... Wed...AM low cigs possible NW Mtns. VFR elsewhere. Thu...VFR conditions. Fri...IFR poss areawide in snow/mixed precip. Sat...IFR/MVFR W in SHSN. MVFR/VFR elsewhere. Gusty wind. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 2 AM EST Tuesday for PAZ004-010. Winter Storm Warning until 5 AM EST Tuesday for PAZ005-006-011- 012-041-042. Winter Weather Advisory until 5 AM EST Tuesday for PAZ017>019- 037-045-046-049-051>053-058. && $$ SYNOPSIS...Dangelo NEAR TERM...Fitzgerald SHORT TERM...Fitzgerald LONG TERM...Fitzgerald/Evanego AVIATION...Dangelo/Colbert
Area Forecast Discussion
National Weather Service Cheyenne WY
448 PM MST Mon Mar 6 2023 .SHORT TERM...(This evening through Wednesday night) Issued at 300 PM MST Mon Mar 6 2023 Afternoon GOES-18 WV/VIS imagery showed a closed upper level low nearly stationary off the WA/OR coast. A broad trough dominated much of the Intermountain West with southwesterly flow aloft. An inverted surface trough extended north-south along the WY/CO front Range. Convergence along this trough has been the focus for snow shower development, albeit more scattered and less intense compared to Sunday. Most of the showers were oriented northeast-southwest from Centennial to Wheatland. Snow accumulations were light with visibilities as low as a few miles. East to southeast winds 10-15 kt with occasional gusts to 25 kt prevailed east of the trough, with westerly 10-20 kt winds to the west. Temperatures were in the 30s. Some lower ceilings persisted across the NE Panhandle. Models/ensembles are in good agreement with the persistent southwest flow throughout the short term. Periodic shortwaves and a stalled surface boundary near the Laramie Range will be the primary focusing mechanisms for snow shower development. The belt of strongest 250mb winds (150kt) weakens and shifts east toward the Upper Midwest during the next 12 to 24 hours. The upper low off the Pacific Northwest coast moves onshore, transitioning to a trough Wednesday morning. The trough tracks east across the Great Basin Wednesday afternoon and the central Rockies and High Plains Wednesday night. Scattered snow showers will continue tonight and Tuesday, tapering off Tuesday night and Wednesday morning. Snow accumulations during this time will Range from 1 to 3 inches over east-central WY, 3 to 5 inches over the Snowy/Sierra Madres, and less than an inch elsewhere. There will be areas of late night/early morning fog along the I-80 Cheyenne to Sidney corridor, with patchy fog elsewhere. As the main trough ejects east across WY/CO Wednesday night, snow showers will become more numerous with large scale lift in the left front quadrant of a 125kt 250mb jet. Moderate snow accumulations are expected with the more persistent showers. Increased PoPs to 60-80 percent Wednesday night. Winds begin to increase Wednesday as the low level pressure gradient tightens in response to the approaching trough. Temperatures throughout the forecast period will average 10-15 degrees below normal. Expect daytime highs in the 20s and 30s with nighttime lows in the teens and 20s. .LONG TERM...(Thursday through Monday) Issued at 300 PM MST Mon Mar 6 2023 Active weather continues into the long term period, but impacts look to remain fairly low at this time. We will be watching for strong winds behind the system on Thursday, and another shortwave to plow through this weekend that may bring renewed mountain snow and strong winds. Models have coalesced around a weaker and faster scenario for the system Wednesday night into Thursday. An upper level shortwave will eject east by Thursday morning, with tight northwest flow wrapping in behind it as ridging tries to build in. Trended faster in the end of snowfall Thursday morning compared to prior forecasts, with appreciable snow after daybreak mostly confined to the mountains, and areas northeast of a Douglas to Sidney line. Gradients tighten in the wake of this upper level low, so expecting northwest winds to increase across the area Thursday morning. The probability for high wind criteria being reached has been increasing, and is highest for the Arlington/Elk Mountain area and the I-80 summit, though fairly widespread windy conditions are likely across the high plains. While we should see the clouds breaking and clearing out for many areas Thursday, it will remain chilly with 700-mb temperatures around -12C to -14C behind this system. Warm air advection finally returns Thursday night into Friday as the axis of a dirty ridge becomes established over the Rockies. Even as warmer air pushes in aloft, Friday morning may be the coldest of the week with a window of less cloudiness possible, contingent on the winds easing at the surface. Guidance has been trending warmer for Friday owing to the faster exit of the previous upper level low. GEFS mean 700-mb temperatures climb to around -5C by midday Friday, which should support temperatures climbing some 5 to 10F over Thursday`s highs, with the greatest differences west of the Laramie Range. Flow aloft turns more west to WSW Friday into Saturday so we could see another round of strong winds developing Friday night into Saturday. There will also be a fair amount of moisture in the flow, so snow showers may return to the mountains and possibly lower elevations west of the Laramie Range Friday afternoon and Friday night. If current expectations hold, advisories would likely be needed for this period in the mountains, with potential impacts extending to the I-80 corridor west of Laramie. Uncertainty is still quite high considering the lead time. Height/pressure gradients will also be increasing again during this time period, so will need to watch for another round of strong winds for the wind prone areas mainly Friday through Saturday. The ridge axis is expected to pass through our area around the early Saturday timeframe. Ensembles have come into much better agreement supporting this longwave ridging moving through, with all GEFS members now showing 700-mb temperatures climbing above freezing by 12z Saturday. The main source of uncertainty in the weekend forecast will be another shortwave passing to our north. This progressive system is expected to be well north, but carry a cold front to the south, while it flattens the ridge and lead to more zonal flow aloft. If the timing is able to hold off until Saturday night, we should manage a very warm day over the high plains. The NBM 75th percentile even pushes KCYS over 60 degrees (would be the first instance of 2023). However, an earlier frontal passage would likely cut 15+ degrees off those numbers. For the official forecast, blended towards MOS and NBM 50th percentile guidance, but will need to watch this frontal passage timing. Lift will be limited with this system outside of the favorable orographics in the mountains, so not expecting widespread precipitation, but we may see some scattered rain/snow showers sometime Saturday afternoon/Saturday night with the frontal passage. Forecast uncertainty increasing considerably for Sunday and beyond. Some ensemble members drop temperatures fairly significantly behind this shortwave, while others have a modest drop and quick rebound. Thus, went with the middle of the road guidance, with most likely scenario resulting in near normal temperatures. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 445 PM MST Mon Mar 6 2023 Confidence growing on a widespread IFR/LIFR event developing later this evening for airports east of I-25. Generally used latest HRRR guidance for onset of conditions at each airport. There is low stratus fairly widespread across Nebraska that will be pulled in this evening with easterly upslope flow. Conditions may continue through Tuesday morning before lifting after 18Z. && .FIRE WEATHER... Issued at 300 PM MST Mon Mar 6 2023 Fire weather concerns will be low as a cold and unsettled weather pattern dominates the districts. Several low pressure disturbances in the southwesterly flow aloft will produce periods of light to moderate snow through Thursday. Winds will increase by the end of the week with stronger winds possible for portions of southeast Wyoming. Warmer temperatures are forecast Friday and Saturday. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MAJ LONG TERM...MN AVIATION...GCC FIRE WEATHER...MAJ
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
947 PM EST Mon Mar 6 2023 .UPDATE... The accumulating snow scenario for tonight is progressing on schedule upstream over northern Lower MI and is set to spread into SE MI with a peak from about 10 PM to 4 AM. It is a fast moving system while bringing a pattern of snow showers with sufficient intensity for a quick 1 to 2 inch accumulation before ending and exiting eastward by 6 AM. This is followed by a drop in temperatures into the mid and upper 20s which could enhance potential for icy roads by sunrise. Mid evening satellite and radar composites illustrate an elevated convective response to forcing associated with the strong mid level circulation and within a corridor of steep mid level lapse rate. Hourly mesoanalysis measured 700-500 mb lapse rate near 8 C/km in this initial area of snow shower expansion. RAP forecasts then project this corridor of elevated instability to progress across the Tri Cities and Thumb region after midnight. Consensus of hi-res models show a concentration of higher intensity snow showers occuring on the south flank of the instability axis where increasingly sheared DCVA focuses vertical motion along/NE of the inverted surface trough. This is where the going forecast positions the snow accumulation axis which begins in the 1 to 2 inch range in the Tri Cities and tapers off as coverage and intensity fade to the south and east. The primary forecast element to highlight is surface temperature trends. Readings are expected to fall into the mid and upper 20s after the snow ends and as clouds clear quickly from north to south through sunrise. This could result in icing of any wet road surfaces or solidifying snow cover as the morning travel period gets underway. Partly to mostly sunny sky is then expected to lift temperatures quickly above freezing toward noon. && .PREV DISCUSSION... Issued at 713 PM EST Mon Mar 6 2023 AVIATION... A band of mixed rain/snow/pellets that was over the DTW corridor followed the primary low pressure system eastward and out of SE MI to start the forecast. It leaves behind a break in precipitation activity but still a wide range of flight conditions ranging from VFR below 5000 ft at MBS to residual IFR ceiling at DTW. Further evolution begins later this evening as the trailing northern Great Lakes wave moves into southern Lower MI. This system brings mainly snow to the terminal corridor beginning first at MBS and spreading southward toward DTW during the late night. Upstream observations show some virga preceding a more active pattern of snow crossing Lake Michigan and in northern Lower MI. Sub 1 mile LIFR visibility is reported from several locations from eastern WI toward the Straits in support of an inch or two of accumulation in SE MI when it arrives. The good news is this system passes through the area rapidly during the late night followed by an equally rapid decrease in clouds. Most locations will be clear to scattered by sunrise followed by a modest rebound in coverage as daytime heating gains traction during the morning. VFR below 5000 ft could become briefly broken before mixing scattered again during the afternoon and clearing into Tuesday evening. For DTW... Residual IFR ceiling recovers into low end MVFR before the next round of snow moves in from the north. A brief shot of IFR visibility brushes the terminal with less than 1 inch of accumulation before the snow quickly ends. Decreasing clouds is then expected into the morning. DTW THRESHOLD PROBABILITIES... * High for cigs aob 5000 feet tonight. Low Tuesday. * High confidence for all snow overnight. PREV DISCUSSION... Issued at 314 PM EST Mon Mar 6 2023 DISCUSSION... Zonal 150 knot upper level jet will anchor a compact mid level wave now featured over central Wisconsin across lower Michigan tonight. Intersection of favorable upper jet forcing with the resident mid level frontal boundary and steep mid level lapse rates the impetus for a solid, mesoscale fgen response over southern sections lower Michigan at press time. This activity will continue to offer bouts of heavier convective showers, with the strongest bursts capable of generating sleet and/or briefly flipping precipitation type to snow despite temperatures generally hovering in the upper 30s to lower 40s. This ascent will vacate to the east this evening, just as an uptick in height falls arrive from the northwest. Renewed increase in large scale ascent tonight as dcva again engages the frontal zone and effectively drags the convergence southeastward with time. This process will effectively initiate weak cold air advection, in turn supporting a precipitation type as mainly snow showers as coverage increases from northwest to southeast. There remains a convective element to this activity, so brief higher intensity rates plausible. Forecast will highlight the potential for 1 to 2 inches of accumulation north of M-59 (highest Saginaw Valley), with less than an inch to the south. A rapid downturn in coverage expected 08z-09z. Seasonable and generally benign early March conditions set for the mid-week period. Steady early day dry air advection under prevailing low level northeast flow should effectively eliminate lingering stratus, affording a high degree of insolation Tuesday. This works to offset a slightly cooler resident thermal profile - highs arriving near average of mid 30s to lower 40s. Ridge of high pressure anchored north of lake Superior then maintains influence under a building upper height field Wed and Thu. Retention of a low level easterly gradient mutes the potential for a more meaningful warming trend, even trending lakeshore communities cooler given the onshore flow. No precipitation forecast through Thursday. Attention by the end of the week focused on behavior of a deeper vort maximum forecast to arrive on the west coast Wednesday before ejecting east or northeast during the late week period. Perusal of the collective ensemble/deterministic model solution space and associated cluster analysis highlight the typical points of uncertainty in terms of defining potential magnitude, amplitude and resulting trajectory of the governing wave. General trend toward a less amplitude mean trough and corresponding northward positioning of the main height fall center as the wave ejects across and out of the rockies, but still with potential for some deepening upon arrival locally Friday and Friday night pending favorable upper jet interaction. Standard implications to the thermal profile and subsequent projection of possible precipitation type trends. Several inches of snow accumulation certainly in play should a deeper, less progressive and colder outcome emerge. MARINE... Light mixed precipitation is ongoing across the local waters this afternoon with rain favored to the south transitioning to snow showers with northward extent. Transition to snow occurs this evening across all waters as colder air temperatures filter in, though precipitation departs well before daybreak Tuesday. Gusts continue to hold aob 30 knots while locked into easterly flow, backing to the north-northwest by daytime Tuesday on the backside of the cyclonic circulation. Transient low level wind field combined with a relatively shallow mixed layer keeps similar wind pattern through mid-week with gusts aob 30 knots. Primary focus is onshore flow elevating wave heights in the mainly ice-free nearshore zones, with Small Craft Advisories in effect through mid-week as a result. Looking ahead to next weekend another potential winter storm brings chances for widespread heavy precipitation and wind gusts possibly to gale force. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory until 4 AM EST Wednesday for LHZ421-441>443. Lake St Clair...None. Michigan waters of Lake Erie...Small Craft Advisory until 10 PM EST this evening for LEZ444. && $$ UPDATE.......BT AVIATION.....BT DISCUSSION...MR MARINE.......MV You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Grand Rapids MI
1026 PM EST Mon Mar 6 2023 LATEST UPDATE... Update .UPDATE... Issued at 1026 PM EST Mon Mar 6 2023 Forecast is on track this evening. A shortwave can be seen diving off to the southeast over Lake Michigan per water vapor imagery. Regional radar loops show a fair amount of precipitation ahead of the wave over Central Lower Michigan. Precipitation type via observations is primarily snow, but there is some rain mixed in as well. The precipitation will continue off to the southeast tonight and exit the forecast area by roughly 400am. A mixture of rain and snow is expected based on temperatures near to slightly above freezing. Some light snow accumulations of an inch or two are possible in the far northeast CWA up towards Reed City and Clare. Clearing will take place late tonight, sweeping from north to south in the wake of the mid level shortwave. && .DISCUSSION...(This evening through next Monday) Issued at 331 PM EST Mon Mar 6 2023 -- Rain and snow tonight -- Rain and occasional lightning in southern Michigan associated with warm advection and isentropic ascent just below 700 mb amid weak static stability will move out the area by nightfall. A batch of precipitation in its wake will then develop over west-central Lower Michigan and move southeast. This is as the 850 mb low and 700-500 mb trough, now located over Wisconsin this afternoon, moves through late this evening. Similar to last night, it will be a rain changing to wet snow scenario especially in a zone between Ludington, Grand Rapids, and Jackson, as air temperatures in the upper 30s this evening cool toward the wet bulb temperatures, which will be just a couple degrees above 32 at the surface and at 32 degrees no higher than 1000 feet aloft. Precipitation should end a few hours prior to the morning commute. QPF in the 12Z HREF and NBM between 0.1 and 0.3 inches centered around Mt Pleasant / Alma would suggest a dense or slushy inch or two, given snow/liquid ratios that will be 10:1 or less. Recent runs of the HRRR have focused the heaviest band of precip even a bit farther south/southwest, into the warmer air and precip-type transition zone. Limited or briefly minor impacts to road conditions are expected, so will shy away from an advisory at this time. -- Uneventful midweek -- High pressure / ridging extending from central Canada through the Great Lakes into the Southeast US will keep the weather on the quieter side Tuesday to Thursday. The sunniest day will likely be Tuesday, with mid- to high-altitude clouds increasing thereafter. A light breeze from the northeast/east is expected. Temperatures will be pretty close to normal for this time of year. -- Potential snow Friday -- The sharp south-to-north temperature gradient across the CONUS will tend to relax in the medium range. By consequence the strong quasi- zonal upper level jet will gradually weaken and fragment into northern and southern streams late in the week. However, an upper- level shortwave / +PV anomaly ejecting from the trough anchored over the west coast on Wednesday will likely undergo baroclinic development in the Midwest on Thu-Fri. Accumulating snow is possible late Thu night through Fri. The ECMWF and Canadian ensembles produce lesser precip amounts than many of the GEFS members, with an advisory-level event being the most likely outcome. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 744 PM EST Mon Mar 6 2023 A weather disturbance will move southeast through the area from this evening into the overnight hours (between 00z and 09z). A mixture of rain and snow is expected as it moves through. Visibilities will dip into the MVFR category at times. Ceilings will lower into the IFR category tonight with widespread IFR expected in place by 04z. Late tonight and into Tuesday morning (between 09z and 13z), conditions will improve to VFR once again. VFR weather is then expected for most of Tuesday as high pressure builds into the region. Northeast to north winds are expected the next 24 hours at 5 to 15 knots with gusts to around 20 knots at times. && .MARINE... Issued at 331 PM EST Mon Mar 6 2023 Winds from the northeast may become hazardous to small craft late tonight as high pressure noses in on the backside of the weak low moving through the southern Great Lakes. Hazardous waves are expected to build beyond 5 nautical miles from shore but may peel toward the shore near South Haven by Tuesday morning. After that for the next few days, winds should be a bit more relaxed from the northeast or east. && .HYDROLOGY... Issued at 331 PM EST Mon Mar 6 2023 The flood watch for the Maple River near Maple Rapids continues for now, though concern for flooding later this week is trending lower. River levels will remain on the high side (not abnormal for spring snowmelt season) after 3 rounds of heavy precipitation over the past two weeks. A few days break with near-normal temperatures should allow rivers time to remain at manageable levels. Slow snowmelt in the Grand and Kalamazoo basins may push river levels a bit higher from where they are now. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory until 8 AM EST Tuesday for LMZ844>849. && $$ UPDATE...Duke DISCUSSION...CAS AVIATION...Duke HYDROLOGY...CAS MARINE...CAS
Area Forecast Discussion
National Weather Service North Platte NE
535 PM CST Mon Mar 6 2023 ...AVIATION UPDATE... .SYNOPSIS... Issued at 340 PM CST Mon Mar 6 2023 Attention continues to focus on a significant winter weather event for the northern Plains which could track south through northern Nebraska Thursday. Today`s model runs of the GFS, NAM, SREF and Canadian show improvements in timing and track. Key messages: -The blended forecast strategy suggests 6-7 inches of across ncntl Nebraska during the 24 hour period ending midnight Thursday. -The ECM and GFS ensemble mean solutions are still too divergent in both location and snowfall amounts to lend moderate to high confidence. They appear to be converging however. The ECM favors SD, MN and IA for the best snowfall while the GFS straddles the NE-SD border into IA. && .SHORT TERM...(This evening through Tuesday night) Issued at 340 PM CST Mon Mar 6 2023 An upper level disturbance across northwest WY this afternoon will track northeast into MT tonight and then east into ND Tuesday. The srn fringe of a deformation zone associated with the disturbance will brush northwest Nebraska tonight and Tuesday morning. The latest model blended solution, which is close to the HREF and the NAMnest, has shifted snowfall amounts north, perhaps as much as 50 miles. The blended forecast suggests less than an inch of snow along and north of highway 20 tonight affecting areas mainly west of Valentine. Light snow is also possible across the Panhandle and other parts of western and north central Nebraska Tuesday with accumulations of a dusting possible. The mechanisms for this snow is modest isentropic lift on the 280-285K surface and upslope wind. This weather type will need to be monitored as there is a split in the models with the RAP suggesting freezing drizzle but the GFS, NAMnest and NAM12 suggesting snow. Temperatures at the saturated h850mb to 800mb layer are -4C to -8C. Low-end chance and slight chance POPs continue place Tuesday night across most of wrn and ncntl Nebraska for what appears to be light snow. This forecast is guarded by the GFS, NAM and NAMnest predicting snow while the RAP continues to suggest the potential for freezing drizzle. .LONG TERM...(Wednesday through Monday) Issued at 340 PM CST Mon Mar 6 2023 Attention continues to focus on a significant winter weather event for the northern Plains which could track south through northern Nebraska Thursday. Today`s model runs of the GFS, NAM, SREF and Canadian show improvements in timing and track. The models are in agreement a closed h700mb should be located across far northeast Nebraska Thursday evening-00z. The models show a h700mb low tracking across nrn Nebraska, near or south of the SD border during the day Thursday. The ECM continues to show the disturbance tracking north of the Black Hills and then southeast toward MN and IA Thursday. This storm track, supported by it`s ensemble mean, would negate winter storm conditions across northern Nebraska. It is worth noting the ECM has chirped up on the prospect of strong WAA driven snow Thursday but the liquid amounts, around 1/3 of an inch, are 1/3 to 1/2 of the stronger operational GFS. Most of the snow from this event will fall from the combination of strong WAA, isentropic lift and convective enhancement. The blended forecast strategy suggests 6-7 inches of across ncntl Nebraska during the 24 hour period ending midnight Thursday. WPC`s day-4 experimental Winter Storm Outlook indicates two counties across ncntl Nebraska eligible for a Watch. No weather highlights will be issued with this forecast. The ECM and GFS ensemble mean solutions are too divergent in both location and amounts. They appear to be converging however. The ECM favors SD, MN and IA while the GFS straddles the NE-SD border into IA. A check on winds shows the best opportunity for strong winds will be Thursday afternoon across southwest Nebraska where the models show a deep mixed layer forming. Sustained winds near 25 mph may develop. Across ncntl Nebraska, these winds would occur Thursday night, but they will be subject to decoupling lessening speeds somewhat. One other weather system may affect wrn and ncntl Nebraska this weekend. The GFS, GEM and ECM are in good agreement carrying the remainder of the over-sized upper low near the coast of the Pacific Northwest east across srn Canada and then southeast through upper midwest. This system should reinforce the cold air in place across the region. A modest warm up is possible Saturday ahead of the system. The ECM and GEM models suggest high temperatures around 50. The stronger GFS suggests 30s to near 40. The blended forecast is in the middle for highs in the 30s and 40s. Regardless of the outcome, the models show colder air from cntl Canada funneling in behind this system. Highs in the 30s and 40s are in place for next Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 535 PM CST Mon Mar 6 2023 Low ceilings are the primary aviation weather concern for western and north central Nebraska terminals through Tuesday evening. The low stratus deck will likely remain in place, resulting in MVFR to IFR conditions. Additionally, snow showers may pass through the northern terminals (KVTN) overnight and again tomorrow. Northeast winds transition to southeast throughout the period, but stay generally near 12 kts. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CDC SHORT TERM...CDC LONG TERM...CDC AVIATION...Snively
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
923 PM EST Mon Mar 6 2023 ...New UPDATE... .UPDATE... Issued at 913 PM EST Mon Mar 6 2023 Arrival time of incoming front still looks to be around 6-9am tomorrow morning. Tightening pressure gradients ahead of the front will counteract nocturnal inversion a bit and keep winds elevated slightly overnight. Will be a dry FROPA tomorrow morning, with only a wind shift noted. Only adjustment to the forecast overnight was to adjust dewpoints a tad. Blended the 23z HRRR and NBM 10th percentile through midnight, then trended mostly towards the NBM 10th percentile for the remainder of the overnight hours. Not a significant adjustment - the NBM mean was just running a degree or two too warm. && .SHORT TERM... (This evening through Tuesday) Issued at 246 PM EST Mon Mar 6 2023 Key Messages: 1. Weak front sweeps through overnight, leading to slightly cooler Tuesday. Discussion: Our stout morning inversion took a little longer than expected to break, but it finally has done so this afternoon and now breezy winds are flowing across the valley. A weak low over the Great Lakes is advecting 25-30 knots of southwesterly 850 mb flow. This combined with the breaking of our morning inversion has allowed for these winds to mix down as gusts. Temperatures outside are 70s valley wide, the warmest of this week. Tuesday morning a cold front will pass through switching our winds to the northwest, bringing slightly cooler weather for Tuesday. Not a lot of moisture available to this front, especially with the delayed return of southerly flow today. Guidance is similarly pessimistic on shower potential, so kept it out of the forecast, but could see an isolated light shower make it through the dry air in some of the higher elevations. Rest of the day on Tuesday will be clearing skies under northwest flow, with slightly cooler but still quite pleasant temperatures. && .LONG TERM... (Tuesday night through next Monday) Issued at 246 PM EST Mon Mar 6 2023 Key Messages: 1. Colder temperatures are expected through this period, with highs generally near to below normal. Some frost will be possible Tue night and Wed night in northern sections. 2. Two main periods of rain chances - Thu/Thu night/Fri, and Sun/Sun night. Discussion: Colder air will be building into the area at the start of the period. Lows on Tuesday night will drop into the 30s for most of the area, and frost will be a possibility in SW VA and NE TN Wednesday morning. The uncertainty with this potential lies with winds, as the models maintain a pressure gradient across the area as the high over the Great Lakes builds south. Wednesday night looks similar, but with the added uncertainty of increasing cloud cover. Rain chances spread into the area with increasing isentropic lift on Thursday as low pressure tracks across the central Plains and the high pressure ridge moves to the Atlantic coast. Low level dry air will likely result in some virga initially, with rain chances increasing from south to north Thursday afternoon as low levels moisten under stronger lift. Peak forcing and QPF comes Thursday night, followed by the cold front passage Friday morning. Expect about a half inch to one inch QPF area wide this period. Cold midlevel temperatures under the closed low may keep scattered to isolated showers in northern sections into Saturday, with some higher elevations potentially seeing some snow. The next system will follow quickly behind and affect the area on Sunday. Model agreement and run-to-run consistency are poor this period, so confidence on details is low, and PoPs will remain in the chance range as a result. The flow aloft is nearly zonal and not well amplified, so this does not appear to be a highly impactful system. A question with this system is whether temperatures will support snow or rain, which will depend on the track of the low. && .AVIATION... (00Z TAFS) Issued at 618 PM EST Mon Mar 6 2023 Winds will likely stay elevated through much of the night (though likely not gusty) as pressure gradients tighten across the region in advance of approaching front. FROPA is expected in the 12z-14z time frame, and should be dry with only some SCT-BKN bases between 4-6k ft AGL as the front passes through. Mixing should be sufficiently deep enough tomorrow to expect some gusts into the mid teens perhaps at all sites. Had highest confidence at KTRI so only included gusts there. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 55 74 41 59 / 0 0 0 20 Knoxville McGhee Tyson Airport, TN 52 67 37 57 / 0 0 0 10 Oak Ridge, TN 51 66 36 56 / 0 0 0 10 Tri Cities Airport, TN 50 61 29 54 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...CD LONG TERM....DGS AVIATION...CD
Area Forecast Discussion
National Weather Service Norman OK
418 PM CST Mon Mar 6 2023 ...New AVIATION... .SHORT TERM... (This evening through Tuesday) Issued at 254 PM CST Mon Mar 6 2023 An initial cold front made it a little further south today than anticipated yesterday, with the pre-frontal trough located across south central OK instead of central OK. Here, temperatures have climbed into the low 80s as expected. The cold front will surge a little further south overnight before stalling near the Red River around sunrise. Meanwhile, aloft, a subtle mid level shortwave trough is expected to traverse NM Tuesday morning and move across northern OK throughout the day Tuesday, while isentropic ascent increases near the same area. Elevated showers, with perhaps brief thunder, will accompany these two lifting mechanisms across northern OK. Further south, near the surface front, some isolated surface based moist convection could initiate but forcing will be weaker there. A conditional threat of marginally severe hail appears possible during the afternoon and evening south of I-40. Considerable cloud cover and the aforementioned rain chances have increased our confidence to lower afternoon high temperatures behind the front tomorrow considering it`s current location. However, even in the short term there is still disagreement on the position of the surface front tomorrow (the HRRR suggests ~72 F at 21Z tomorrow while the NAM nest is ~42!) && .LONG TERM... (Tuesday night through next Sunday) Issued at 254 PM CST Mon Mar 6 2023 Higher rain chances are expected to develop later overnight Tuesday as deeper isentropic ascent commences. There`s still some uncertainty on the placement of the main core of precipitation near the ~925 mb front late Tuesday but the general consensus is along and just south of the I-44 corridor. Some heavy rainfall will be possible into early Wednesday morning, with anomalous PWATs and training showers/storms possible. In addition to heavy rainfall, there could be some marginally severe hail considering just enough deep layer shear and elevated instability, but lapse rates should limit the overall threat. The highest chances for severe weather should be limited to the southern half of OK and portions of north TX where more buoyancy is present. The first main round of precipitation should exit our forecast area eastward late Wednesday morning. However, redevelopment appears likely by early Wednesday evening as a subtle PV anomaly lifts northeastward out of West TX and a LLJ intensifies. The axis of heaviest rainfall will again depend on where the frontal boundary and near surface baroclinic zones are. There is still much uncertainty regarding QPF. Wednesday night into early Thursday morning may have the best potential for both marginally severe storms and localized flooding. A flood watch may be considered by the overnight shift, if confidence increases in the areas of heaviest rainfall. This may be mainly for ESE OK where soils remain moist from recent rainfall and training could continue within persistent WSW mid level flow. Forecast confidence decreases even more late in the week through the weekend. During the day Thursday, a mid to upper level shortwave trough is expected to move out of the central Rockies and into the central plains, with an accompanying cold front perhaps entering far northwest OK. Rain chances should still be ongoing across our southern and southeastern zones, as a warm front lifts northward there. Overall, it appears rain chances should end late Thursday as the cold front surges southward across the Red River with a much drier airmass behind it. && .AVIATION... (00Z TAFS) Issued at 354 PM CST Mon Mar 6 2023 Northeast to east winds will persist through Tuesday. MVFR ceilings are expected to form at most TAF sites after daybreak Tuesday. Scattered rain showers are expected in north central Oklahoma before noon and will likely increase and develop more widely by late afternoon. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 47 56 44 55 / 0 20 70 60 Hobart OK 45 55 43 55 / 0 20 60 30 Wichita Falls TX 53 70 49 60 / 0 20 60 60 Gage OK 37 45 37 52 / 0 10 20 10 Ponca City OK 39 48 43 53 / 0 50 50 60 Durant OK 56 75 57 68 / 0 20 70 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ SHORT TERM...03 LONG TERM....03 AVIATION...09