Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/11/19

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
536 PM CST Sun Feb 10 2019 .UPDATE... Issued at 528 PM CST Sun Feb 10 2019 Made some adjustments to precip onset time tonight and Monday morning. Otherwise, no further changes were needed this evening. && .SHORT TERM...(This Evening through Monday Night) Issued at 250 PM CST Sun Feb 10 2019 Forecast challenges include cloud coverage through late this evening and snow timing/coverage/amounts on Monday/Monday night and freezing drizzle potential over the Coteau Monday morning through early afternoon. Currently, temperatures range from around zero to near 10 degrees throughout the CWA. Earlier cloud-cover associated with accumulating snow has moved off into Minnesota, leaving partial coverage of stratus clouds around the area. And some of that cloudiness appears to be dissipating as it gives off one last burst of very light snow/flurries. Reports trickling in suggest that anywhere from 1 to 3 inches of fluffy snow (generally less than a tenth of an inch water equivalent in this snow) has fallen today. Winds have a predominant northeasterly direction and are running generally 5 to 15 mph. Overnight, additional low clouds are expected to develop/move north over the region as a low pressure system over Montana/Idaho heads this way. With it being cold enough (even in the stratus layer) to activate ice, continuing an isolated flurry mention out of this forecast low stratus until the better WAA-forced precipitation gets going on Monday. That being said, both the RAP and 12Z NAM12 output in BUFKIT today supported the notion that the temperature in the (deep enough to produce drizzle) stratus layer may warm up enough out over the Prairie Coteau and points east Monday morning to produce some freezing drizzle instead of flurries and potentially persist into early Monday afternoon. But, once mid-level saturation (within the DGZ) from the WAA-forcing sets up over the east, the temperature of the low level stratus becomes moot, and p-type would just be all snow. It`s not clear if the freezing drizzle potential will reach much farther west or north of the Coteau Monday morning. For now, concentrating the freezing drizzle mention out over the Coteau over into west central Minnesota. There has been a general back-peddling on qpf/snow amounts in the models for three days in a row now, and tomorrow/night`s precipitation event now looks to be a generally light snow event with amounts ranging from an inch or two across the Missouri River valley to 2-4 inches across the SoDak/MN border area. Wind speeds have continued to decrease as well for this event, with generally 15 to 25 mph winds expected. This yielded some "patchy blowing snow" mention on Monday. The WAA and surface/PBL winds out of the southeast on Monday are expected to produce somewhat warmer temperatures, with readings up into the teens and 20s (sadly, this is still below climo normal for this time of year). The low level CAA Monday night that will be lagging behind the snow event by just a few hours will re-assert more of the much below normal cold air into the CWA. .LONG TERM...(Tuesday through Sunday) Issued at 250 PM CST Sun Feb 10 2019 Storm system will be departing the area to the east on Tuesday, with another shot of cold air moving into the region. Given how cold the 925mb temps are, it seemed SuperBlend might be a little too warm for highs on Tuesday. Also noticed several models were colder than SuperBlend, so did basically a 50/50 split between SuperBlend and the colder feel of the ADJECE guidance. Temperatures for the rest of the extended period were left as inherited. For winds, increased things a bit on Tuesday on the back side of the departing storm system. Also used more of the higher CONSMOS/EC feel for winds during the Thursday/Thursday night system. As for precipitation, the main player is this system that moves through Thursday into Thursday night. Model agreement has become better as far as timing goes, and they all appear to bring more light to moderate snow accumulations to the area. As of now, it would appear higher accums may be across the western CWA, but still much to sort out before we get to that point as it`s still several days away. && .AVIATION...(For the 00Z TAFS through 00Z Monday Evening) Issued at 528 PM CST Sun Feb 10 2019 A mix of cigs this evening is expected to become mostly IFR as snow and blowing snow move through the region on Monday. Conditions will improve to MVFR when the snow ends toward the end of the period. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Wise SHORT TERM...Dorn LONG TERM...TMT AVIATION...Wise
Area Forecast Discussion
National Weather Service Buffalo NY
954 PM EST Sun Feb 10 2019 .SYNOPSIS... A weak front will move southeast across the area tonight with spotty light snow and very minor accumulations. A stronger storm system will move into the eastern Great Lakes late Monday night and Tuesday. This will spread accumulating snow into the area, which will then change to a wintry mix and even just rain in some areas later Tuesday before changing back to snow by Wednesday as colder air moves back into the region. && .NEAR TERM /THROUGH MONDAY/... Light snow has moved into the western Southern Tier this evening. Dry air in place is keeping light snow from reaching the ground across the rest of western NY. This will soon change as isentropic lift and mid- level moisture continue to increase. Moisture advection will prove just efficient enough to properly saturate the column with enough depth to translate into a period of light snow across western and north central NY. Model guidance shows a notable decrease in forecast magnitude and duration of mid level upward vertical motion across the area. The short residence time of both greater moisture depth and meaningful forcing generally 4 to 6 hours will keep accumulation potential limited to an inch or less for most locations, largely centered between 9 pm and 3 am. There may be a brief period of very minor lake enhancement along the south shore of Lake Ontario late tonight when 925-850mb flow becomes northeast from Monroe to Niagara counties, but any enhancement to accumulations will be minimal. As we get later into the overnight period and into Monday morning profiles showing mid level moisture decreasing causing a marginal thermal profile which become less favorable in supporting mid level ice nucleation, therefore become increasingly susceptible to a possible mix or switch to supercooled droplets. This may introduce a window for the potential for some freezing drizzle as moisture quality only slowly diminishes with time below 5k feet. Any ice accretion potential likely minimized by the limited overall coverage and intensity, while also falling on top of freshly fallen snow. Later shifts will need to monitor how this unfolds. A break in the precipitation is expected for most of Monday as moisture in temporarily shunted south of the area as drier air around high pressure over western Quebec works into the area. This will allow for some clearing skies, especially for areas east of the Finger Lakes. Temperatures will be seasonable with highs in the 20s to lower 30s across southwestern New York. && .SHORT TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/... ...Winter Storm Warning Issued for the North Country... During the first 36 hours of this period...the 12z/10 guidance suite remains in good agreement on ejecting an increasingly negatively tilted upper level trough northeastward across the Plains States... Great Lakes...and into the Northeastern States. Meanwhile at the attendant initial cutter-type low will steadily deepen as it tracks from the south-central Plains to the central Great Lakes Monday night and Tuesday...with the low then passing by a little to our north and filling Tuesday night as it begins transferring its energy to a secondary surface cyclone developing off the New England coastline. This system will be accompanied by increasingly plentiful moisture and deep forcing for ascent as it approaches and passes through our region...resulting in light precipitation initially developing into portions of far western New York Monday night...before overspreading the remainder of the region and becoming steadier/heavier on Tuesday...then continuing right on through Tuesday night. With respect to precipitation type...our airmass will initially be cold enough for this to start off as some light snow Monday night and early Tuesday morning. As we move through Tuesday and Tuesday evening though...a surge of milder air...first aloft and then at the surface...will push into western New York out ahead of this system`s trailing cold/occluded front. This will result in the snow giving way to a wintry mix and eventually a cold rain for the bulk of the area south of Lake Ontario...where surface temperatures currently look to climb into the mid to upper 30s later Tuesday and Tuesday evening. Further to the northeast colder air will hang tough across the North Country...resulting in the precipitation primarily remaining in the form of snow through Tuesday evening. As we push through the second half of Tuesday night and Wednesday morning the surge of milder air will try to push further northeastward... but will become increasingly muted and pinched off on both sides as the cold/occluded front pushes across western New York...and as the developing secondary surface low off the New England coastline wraps colder air back into our region from the northeast. The end result of all this will be rain mixing with and then changing back to snow across western New York...while mixed precipitation MAY push into portions of the North Country for a short period (mainly south of Tug)...before also transitioning back to all snow. Lingering wraparound moisture...cold air advection...and upsloping behind the consolidating low will then lead to continued lighter snow through the second half of Wednesday. In terms of potential snowfall this still-early juncture it still appears that the best potential for a significant (i.e. warning- criteria) snowfall will lie across the far eastern Finger Lakes/Eastern Lake Ontario region and especially the North Country...where the potential for any mix will be lowest and the briefest...and consequently the precip should remain in the form of snow the longest...potentially leading to total snowfall accumulations of 12 to 18 inches over a rough 24 to 36 hour period. Have thus upgraded the Winter Storm Watch for Jefferson and Lewis counties to a Winter Storm Warning. Elsewhere... snowfall amounts should decrease with increasing southwestward extent owing to the progressively earlier arrival of the milder air and the attendant wintry mix/changeover to rain...though current projected snowfall amounts and the potential for a wintry mix of sleet/freezing rain will still likely eventually warrant Winter Weather Advisories. As has been pointed out goes without saying that all of this remains highly dependent upon the exact track/strength of the initial primary low and how quickly the transfer of energy to the secondary coastal system takes place. A more northwesterly track to the primary low...a stronger primary low...and/or a delayed transfer of energy to the coastal system would all point to a warmer overall scenario and less snow areawide...while the opposite conditions would favor a colder scenario and more snow overall. One other hazard this system could present may be a couple rounds of stronger gusty winds. The first of these could come in the form of strong southeasterly downslope winds along the Lake Erie shoreline during the day Tuesday...with the NAM/GFS (both of which have a stronger primary low following a more northwesterly track...and consequently a stronger associated southeasterly low level jet) currently suggesting this possibility. The second would be a possible round of stronger west-southwesterlies/westerlies across western New York following the passage of the trailing cold/occluded front later Tuesday night and Wednesday has been consistently advertised by the GFS over the past several days. While the potential for both will greatly depend on the track/strength of the primary low and how quickly it transfers its energy to the secondary coastal this point at least some advisory-worthy winds appear a possibility during both of these time will add a mention of both to the HWO. Following the passage of this system...lingering scattered to numerous snow showers (most numerous downwind of Lake Ontario due to lake enhancement) will diminish from west to east Wednesday night as high pressure and drier air build across our region...and as warm air advection commences aloft. Otherwise drier and quieter conditions can be expected...with overnight lows settling into the upper teens to lower 20s. On Thursday the surface ridge axis will slide off to our east...while yet another notable southern-stream system pushes into the central Plains states...thereby placing our region within a broad southwesterly flow of milder air. This will allow high temperatures to recover back to above normal fairly quickly...with highs returning to the lower to mid 30s across the North Country and to around 40 south of Lake Ontario. Meanwhile the bulk of the day should be dry...with the overall warm air advection regime/development of a warm frontal boundary possibly leading to just a few spotty light rain or snow showers along and north of the I-90 corridor. Finally...during Thursday night the surface low will make its way further northeastward into the Upper Midwest. Continued broad warm air advection well out ahead of this system may support some additional scattered rain and snow showers across our region...along with milder (and mainly evening) lows ranging from the mid 20s across the North Country to the mid 30s across western New York. && .LONG TERM /FRIDAY THROUGH SUNDAY/... It will be quite unsettled over our forecast area for the bulk of this a very active southern stream within a split flow will pound the area with yet ANOTHER significant storm system. In fact...there could very well be another round of headlines. The active southern branch of the jet should come as no surprise to those familiar with ENSO Pacific based storms within moderate to strong El Nino`s often make their away across the southern half of the country before making the turn to the Great Lakes or Northeast. There is currently a moderately strong El Nino in place across the Equatorial Pacific. Now the day to day details. A deepening cyclone will track northeast across the mid western states on Friday...with its associated warm frontal boundary extending across the western counties of our forecast area. While there is high confidence in this general scenario...the subtlety as to whether the warm front can actually move past the south shore of Lake Ontario is still being debated by the various guidance packages. Why is this important? Temperatures Friday will approach 50 across the Southern Tier in the wake of said front...but there will be a tight thermal gradient to Lake Ontario...with temperatures near the south shore and also over the Eastern Lake Ontario region possibly having trouble climbing out of the 30s. Both the ECMWF and particularly the GFS operational runs suggest the colder solution for these areas. This will present the headache of mixed precipitation... which should be found across the bulk of the region for at least the early morning. The mix of rain or wet snow could also include some freezing rain...but from this range...will avoid complicating an already complex system. That all being said...mixed precipitation will spread northeast across our forecast area during the course of Friday. Fairly widespread rain should be found west of the Finger Lakes and also for the Thousand Islands region for the afternoon. The deep storm system will advance to western Lake Erie by Friday evening where it should begin the process of transferring its energy to the coast. As we have already seen several times in the past few weeks...ANOTHER Miller B cyclogenetic event. Watch for closed mid level storms with a negative tilt for keys to these they are often more telling than the actual MSLP output. For what its worth...the ECMWF seems to do very well with these patterns. In this particular case though...both the ECMWF and GFS based ensembles seem to be in solid agreement. In fact...the GFS has been locking in on this solution for the past 3 days. This only adds to the very confidence in the pops...which will be restrained to just 90 for better collaboration. Deep lift will be provided by plummeting heights...a divergent UL flow...and significant forcing from being under the RR entrance region of a 100kt jet over Quebec. This lift will be applied to a deep plume of sub tropical its possible that rainfall amounts could exceed a half inch. By Saturday morning...the transference of energy to the New England coast should be nearly complete. This will leave a general weakness in the pressure field over our forecast area where the primary low would be. While we will lose our deep forcing...there will still be enough lift from convergence within the mid level trough to support fairly widespread rain and snow showers that will change to all snow showers by the afternoon. Given the pressure gradient on the backside of the sub 980mb secondary should become rather windy over our area as well. Saturday night and Sunday...the secondary storm will chug across the open St Lawrence to eastern Quebec and eventually the Labrador Sea. A deep cyclonic flow of moist...increasingly cold air will keep the likelihood of snow showers in place for our forecast area...with lake enhancement expected southeast of both lakes...especially Lake Ontario. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Mid level clouds will continue to thicken and lower ahead of weak frontal boundary tonight. Light snow will track across western NY tonight reaching KIAG,KBUF, KROC and KART by 4z. This will cause some MVFR flight restrictions and spotty IFR vsbys. Snow will be spotty and may cause flight conditions to change frequently into Monday morning. Light snow may transition to freezing drizzle across western NY through Monday morning. This may also keep conditions sub- VFR. Low clouds will likely stick around through most of the afternoon resulting in MVFR conditions. Outlook... Monday night...Deteriorating to IFR late with snow developing. Tuesday...Areas of IFR with snow changing to wintry mix and then rain. Wednesday...Areas of IFR with snow likely. Thursday and Friday...Mainly VFR. && .MARINE... Northeast winds will increase late tonight and Monday as the pressure gradient tightens between high pressure over Quebec and low pressure moving into the Upper Midwest. This will bring another round of Small Craft Advisory conditions to the south shore of Lake Ontario. The easterly winds will continue to strengthen Monday night and Tuesday as the low approaches. This low will cross the eastern Great Lakes later Tuesday night, with winds becoming southwest Wednesday with Small Craft advisory conditions continuing. Gales force winds are possible on Lake Ontario. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Winter Storm Warning from 10 AM Tuesday to 10 PM EST Wednesday for NYZ007-008. Winter Storm Watch from Tuesday morning through Wednesday evening for NYZ005-006. MARINE...Small Craft Advisory from 6 AM Monday to 10 PM EST Tuesday for LOZ042-043. && $$ SYNOPSIS...TMA NEAR TERM...HSK/TMA SHORT TERM...JJR/RSH LONG TERM...RSH AVIATION...HSK/TMA MARINE...HSK/TMA
Area Forecast Discussion
National Weather Service Fort Worth TX
935 PM CST Sun Feb 10 2019 .UPDATE... /Tonight/ Only notable change with this update is the increasing of PoPs over parts of western North Texas, where another subtle shortwave impulse is yielding a band of generally light rain this evening. The expectation is for this band to slowly shift northeast, while a low-level warm conveyor gradually matures along/east of the I-35 corridor after midnight. Rain chances will accordingly increase here as well. Visibilities have been slow to fall with any consistency across the region, perhaps due to some veered low-level flow in the wake of a subtle mid/upper trough departing to our north over Oklahoma. As such, no plans to hoist a dense fog advisory anywhere at this time. However, in tandem with the aforementioned maturation of a warm-advection corridor, hi-res/probabilistic guidance still suggest visibilities may fall close to advisory criteria across parts of East Texas and perhaps near the Red River after midnight. These trends will be monitored accordingly. Picca && .AVIATION... /Issued 612 PM CST Sun Feb 10 2019/ /00Z TAFs/ Continued poor flying conditions expected through daybreak. Main challenge remains the timing of category changes for both CIGs and VSBYs. With one weak/low-amplitude impulse skirting portions of northwest Texas at present, some enhancement of warm-air advection across our region has kept CIGs generally around LIFR levels. Expect these ceilings to remain around 002-004 through 02-03Z. They may rise slightly to 004-008 around 03-06Z, but confidence in this scenario is not particularly high. Likewise, VSBYs may improve slightly by 02-03Z. This may occur perhaps even sooner but given nightfall and the likely presence of unresolved upstream impulses, think a TEMPO for IFR VSBY is still warranted through 03Z. Most guidance and observational evidence then suggest conditions should worsen further around 06-07Z, in response to another surge in low-level moistening/ascent. Maintained mention of occasional LIFR, and there is some possibility CIGs/VSBY could fall to near airport mins after 06Z. However, the worst conditions may remain just east of all TAF sites, and confidence in VLIFR is too low to include in TAFs. Drying above the surface will become more earnest around 12-15Z Monday. Therefore, continue to advertise a slow improvement trend through the morning. Do think it will be a gradual improvement (and not particularly fast) owing to persistent southwesterly flow aloft and remaining near-surface moisture. As surface flow increases and veers more southwesterly through the afternoon, though, conditions should rise to MVFR and eventually VFR. There is some potential for VFR CIGs to be delayed until after 12/00Z at KDFW, however. Picca && .SHORT TERM... /Issued 309 PM CST Sun Feb 10 2019/ /Tonight/ The main concerns through the overnight hours will be periods of drizzle, light rain and fog. Surface analysis revealed that southerly flow was beginning to envelop much of the area this afternoon in response to lee-side surface pressure falls to the north. Rich low level moisture remains confined to the upper TX coast at this time, but as surface flow continues to veer, some of this moisture should make a run northward into parts of North and Central Texas. The warm and moist advection should result in near steady or rising temperatures. With isentropic upglide expected to continue, there will be a a continued risk for light measurable rainfall along with drizzle and some fog. Increased surface moisture, per RAP soundings, into this airmass signals more of an advection fog type setup tonight. A consensus of hi-resolution guidance supports reduced visibility down to 1/2 a mile and I wouldn`t be surprised to see some areas of dense fog...especially near and east of I-35. For now, we`ll hold off on any advisories, but one may be needed late tonight into early Monday. Otherwise, temperatures should remain in the 40s areawide. Bain && .LONG TERM... /Issued 309 PM CST Sun Feb 10 2019/ /Monday Onward/ Areas of fog are likely to continue into Monday morning as south winds usher ample moisture northward into a cooler airmass already in place. Some warming will occur throughout the day via warm advection as strong low-level southerly flow prevails. While one wave of precipitation will be exiting the area around daybreak, another will develop off to the west later in the day as an approaching shortwave trough swings through the Plains while becoming negatively tilted. This will cause mid-level lapse rates to steepen via cooling during the afternoon and evening hours, which may result in a few thunderstorms near or east of I-35. Instability is expected to be very limited, which should confine hazards to occasional lightning or at most some small hail across our eastern zones. As the upper trough`s associated surface low accompanies it eastward late Monday, a cold front will be pulled through the region, scouring moisture while bringing rain chances to an end from west to east. In wake of Monday`s front, cooler and dry conditions are expected to prevail through the middle portion of the week. Temperatures will generally be within a few degrees of seasonal normals as a slow warming trend occurs through Wednesday. Zonal flow aloft will prevail throughout the time period, and moisture will largely remain scoured from the forecast area. By Thursday, a dynamic storm system is expected to dive into the Plains, prompting strong lee cyclogenesis. A deep surface low will develop through southeastern Colorado and drift eastward through Kansas and Oklahoma. This surface pattern will result in veered low-level winds across our forecast area, which should make for a warm and breezy day as the pressure gradient tightens. With west winds and increased downsloping, 70s are likely area-wide and some of our western zones may flirt with 80 degrees. Moisture return will be fairly limited with this setup, so despite the dynamic storm system, precipitation may be confined to some warm advection showers east of I-35 Thursday afternoon. At this point, it appears most areas will remain rain-free. The strong and rather deep southwesterly flow should keep a stout lid on any surface- based convective attempts with what meager moisture will be available in the first place. Given the windy and warm conditions with low RH values along with limited rainfall in recent weeks, there may end up being some elevated fire conditions Thursday afternoon west of I-35. Thursday night and Friday morning, this system`s strong cold front will push through the forecast area turning winds abruptly to the north at 20-30 mph. At this stage, it appears moisture will be too meager to support any precipitation along the front. Strong cold advection and post-frontal stratus should keep temperatures 20 or more degrees cooler than Thursday with highs likely only in the 40s or lower 50s. The cool weather will continue heading into next weekend, with temperatures expected to be around 10 degrees below normal on Saturday. -Stalley && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 43 65 40 58 35 / 60 40 20 0 0 Waco 45 66 43 59 35 / 40 60 20 0 0 Paris 41 62 40 54 32 / 90 90 40 0 0 Denton 42 64 38 58 33 / 60 40 20 0 0 McKinney 43 64 40 56 33 / 70 60 20 0 0 Dallas 43 65 41 58 36 / 60 50 20 0 0 Terrell 43 64 40 57 33 / 80 70 30 0 0 Corsicana 43 65 42 57 34 / 70 60 30 5 0 Temple 45 66 43 60 35 / 40 60 20 0 0 Mineral Wells 43 65 36 58 33 / 60 30 10 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 11/30
Area Forecast Discussion
National Weather Service Hastings NE
552 PM CST Sun Feb 10 2019 .SHORT TERM...(This evening through Monday Night) Issued at 317 PM CST Sun Feb 10 2019 The main concern with this forecast issuance is the freezing drizzle that is expected late tonight through Monday. This evening into tonight, we will see winds gradually become easterly to southeasterly. This upslope flow accompanied with isentropic lift ahead of another approaching shortwave should be sufficient to produce widespread low stratus and light precipitation by Monday morning. Model soundings continue to be very indicative of freezing drizzle. The HRRR shows a fully saturated profile from the surface to nearly 750mb by 6am Monday, with absolutely no saturation in the dendritic layer. Most all models continue to output 0.05-0.10" of QPF with this activity as well. I think the 18Z HRRR solution looks very reasonable with regards to timing and coverage/impacts. The advisory has been expanded southward as it appears that the entire area will see at least light icing Monday morning. By Monday afternoon, things become a little more uncertain across southern areas though. Temperatures have trended colder, but afternoon highs may still rise above freezing...especially in north-central Kansas. As a result, we may just see drizzle and reduced impacts for several hours before temperatures fall back below freezing in the evening. Models continue to show a brief window for light snow during the afternoon and evening, but accumulation will be very minimal for most locations. Northeastern portions of the forecast area will be the heaviest, but still should be around one inch or less. Precipitation will wind down from west to east as the upper level trough axis moves through Monday evening. .LONG TERM...(Tuesday through Sunday) Issued at 317 PM CST Sun Feb 10 2019 Dry conditions prevail Tuesday and Wednesday as the trough deepens over the Great Lakes and we see rising heights aloft. Temperatures are also expected to make a nice recovery by Wednesday, with forecast highs now ranging from the low 40s to mid 50s. Winds will be relatively light, so this appears be the nicest day of the week. The next disturbance is expected to move through on Thursday afternoon into Friday morning. This appears to be a quick-moving wave, but models are still showing that it could produce a swath of significant snow for portions of the area. Details on this system will hopefully come into better focus over the next few days. This system will also usher in another shot of cold air, which, when coupled with the gusty north winds on the back side of the low, may push wind chills down into the -10 to -20 range across portions of Nebraska. Cold weather will continue Saturday and Sunday. While not completely dry, the the overall threat for significant snow appears relatively low as we head into next weekend. && .AVIATION...(For the 18Z KGRI/KEAR TAFS through 18Z Monday) Issued at 1126 AM CST Sun Feb 10 2019 Generally poor conditions are expected at both terminals through the period as MVFR/IFR conditions this afternoon are only expected to worsen and become LIFR overnight as fog is expected to develop over the next couple of hours as CIGS lower...and freezing drizzle is expected to become widespread before daybreak. While this drizzle may transition to snow...especially at KEAR late in the day...kept freezing drizzle in both TAFS from 11/10Z through the end of the period...with a slight improvement in CIGS late in the day. Winds overall will be less than 12 KTS through most of the period and generally out of the east...and shifting from the north late in the day. && .GID WATCHES/WARNINGS/ADVISORIES... NE...Winter Weather Advisory from 3 AM Monday to midnight CST Monday night for NEZ039>041-046>049-060>064-072>077-082>087. KS...Winter Weather Advisory from 3 AM Monday to midnight CST Monday night for KSZ005>007-017>019. && $$ SHORT TERM...Mangels LONG TERM...Mangels AVIATION...Mangels
Area Forecast Discussion
National Weather Service Green Bay WI
545 PM CST Sun Feb 10 2019 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Monday Issued at 519 PM CST Sun Feb 10 2019 The latest RAP analysis and satellite/radar imagery show low pressure centered over western Kansas and a surface trough extending northeast from just south of La Crosse to around Manitowoc. Meanwhile, an elongated shortwave trough is moving into western WI early this afternoon. In the warm advection regime ahead of the shortwave, snowfall expanded across northeast WI by early in the afternoon, after mid-level fgen contributed to a snow band that produced 1-3 inches across the Highway 29 corridor during the morning. The shortwave will continue to move northeast from southwest MN across northern WI this afternoon, and should see an uptick of snowfall intensity at locations which were not positioned under the snow band earlier today. Forecast concerns generally revolve around additional accumulations with the ongoing system. Tonight...The shortwave will move across northern WI this evening. Mid-level drying will be occurring behind the shortwave, so should see the snowfall diminish from southwest to northeast during the evening. Highest additional amounts around 1" should therefore reside over far northeast WI, which would place total accumulations in the 2-4 inch range at most locations, lowest across the far north and from Wautoma to Manitowoc. A few locations around the Highway 29 corridor, which saw more intense snowfall in the morning, may see 5-6 inches by the time the snow ends. No additional changes to the advisory at this time. Wouldnt be surprise to see scattered flurries persist overnight due to some moisture lingering above the inversion. However, will just leave a chance along the Lake Michigan shoreline where onshore flow will continue through the night. Under cloudy skies, temps should not fall very much and range from around 10 degrees across the north to 20 degrees near Lake Michigan. Monday...The region will be between weather systems. Weak descending motion will be occurring in the 850mb-500mb layer. However, progged soundings indicated moisture will be trapped beneath the inversion which should result in cloudy conditions persisting. Wouldnt be surprised to see some flurries, or patchy freezing drizzle occur, particularly near Lake Michigan where easterly flow will continue. Will just leave a flurry chance near the Lake in the morning, but will pass concerns on to the next shift. Temps will be warmer, and range from the mid 20s in the north to the upper 20s southeast. .LONG TERM...Monday Night Through Sunday Issued at 519 PM CST Sun Feb 10 2019 Main forecast concerns are the winter storm and associated headlines Monday night into Tuesday evening, and the next system Thursday into Friday. Low pressure near the TX/OK panhandles on Monday evening is expected to lift northeast and reach southeast Lower Michigan by Tuesday evening. Developing isentropic lift ahead of the approaching low will cause precipitation to develop Monday night. Initially, moisture will be quite shallow, and the presence of ice is questionable, so would expect a mix of light snow and freezing drizzle to break out during the mid to late evening. Deeper saturation and strong lift will likely not occur until late Monday night or very early Tuesday (far northeast WI), and that is when heavy snow is expected to overspread the region. A negatively- tilted upper trof is expected to move into the region and form a cut-off low by evening. This feature will continue the threat of heavy snow into the afternoon, and cause at least light snow to linger into the evening. Total snow accumulations should be in the 7 to 10 inch range, so a watch will be issued this afternoon. Start time of the watch is problematic, as the heavy snow is not expected until later in the night. However, offices to the west and south are starting up between 00z-03z/Tues and the threat of freezing drizzle will ramp up during the mid to late evening, so have tiered our start time from 03z-06z/Tue. Continued light snow and some blowing and drifting can be expected Tuesday evening, so will not end the watch until 06z/Wednesday. Another system is expected to arrive Thursday afternoon or evening, and could bring advisory criteria snow to roughly the southern two-thirds of the forecast area through Friday. Some lake-enhancement could occur along Lake Michigan, resulting in the highest amounts toward Two Rivers and Manitowoc. Next weekend is setting up to be much quieter, with high pressure in place. && .AVIATION...for 00Z TAF Issuance Issued at 545 PM CST Sun Feb 10 2019 Light to moderate snow will continue to impact the region this evening before steadily diminishing overnight. IFR/MVFR visibilities can be expected through much of this time; however, intermittent LIFR conditions are possible under the heavier snow showers, especially for the southern TAF sites. IFR ceilings will likely linger through much of the rest of the TAF period as low-level moisture remains in place. There could be some flurries or light freezing drizzle through the day Monday, but confidence in that happening is low. Otherwise, attention will then turn to the potential for moderate to heavy snow overnight Monday night through much of the day Tuesday. Significant snowfall accumulations are expected for that time period. && .GRB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until midnight CST tonight for WIZ010- 011-013-019>022-031-037>040-045-048>050-073-074. Winter Storm Watch from Monday evening through Tuesday evening for WIZ030-031-035>040-045-048>050. Winter Weather Advisory until 9 PM CST this evening for WIZ018- 030-035-036. Winter Storm Watch from late Monday night through Tuesday evening for WIZ005-010>013-018>022-073-074. && $$ SHORT TERM.....MPC LONG TERM......Kieckbusch AVIATION.......Cooley
Area Forecast Discussion
National Weather Service Indianapolis IN
624 PM EST Sun Feb 10 2019 .UPDATE... The Aviation section has been updated below. && .SYNOPSIS... Issued at 255 PM EST Sun Feb 10 2019 A warm front will approach and settle near Central Indiana tonight and Monday. This will bring snow this afternoon and evening and rain...possibly resulting in flooding...on Monday to Central Indiana. A FLOOD WATCH is in effect for much of Central Indiana late tonight through early Tuesday morning. A strong cold front will bring more rain to Central Indiana on Tuesday along with windy conditions. Dry weather is expected for Wednesday as High pressure arrives in the wake of the cold front. More precipitation is expected to arrive on Thursday and Friday as another weather system arrives in the region. && .NEAR TERM /Tonight/... Issued at 255 PM EST Sun Feb 10 2019 Surface analysis early this afternoon shows a warm front in place across Central Indiana. Low pressure was found across the western Missouri. Radar shows area of snow showers across Central Indiana...and rain showers south of the warm front across Kentucky. GOES16 shows a stream of tropical moisture set up once again...stretching across Mexico and Texas then northeast to the Ohio Valley. THE GFS And NAM continue to keeps the plume of tropical moisture streaming into the Ohio Valley tonight and into Monday. Embedded short waves within the flow are indicated to pass through the region. Forecast soundings and time heights both suggest a mostly saturated column tonight...but best forcing is exiting the area late this afternoon and arriving again toward 12Z monday. HRRR suggests some dry air arriving from the west...limiting the northward propagation of the precipitation this evening...leaving the focus farther south. GFS mid levels suggest the next best surge of moisture arriving from the southwest after 09Z. The 290K Isentropic surface shows waning up glide this evening with specific humidities over 4 g/kg. Given the weak warm air advection in place...forecast soundings also show a slow warming trend through the night...with areas along I-70 rising above freezing at or shortly after 12Z. Thus forecast builder willing...precip type will be snow north...mix central and Rain south tonight. Will focus best pops through the night across the southern parts of Central Indiana and trend toward lower pops farther north where moisture appears to be less focused. Overnight as the next mid level surge of moisture arrives...will trend pops upward across the board. Given the expected warm air advection will trend highs at or above the forecast builder blends. && .SHORT TERM /Monday through Wednesday/... Issued at 255 PM EST Sun Feb 10 2019 Active and wet weather is expected this period. The tropical plume of moisture streaming into the Ohio Valley is expected to persist through Monday and Monday Night. Again...Several short waves with the moist flow will continue to provide forcing for rainfall. Forecast soundings Monday and Monday night remain saturated with excellent lift available. meanwhile at the surface a warm front is expected to linger across Kentucky...putting Central Indiana in an ideal spot for overruning precipitation. Forecast soundings show deep moisture available with a lower level warm air advection inversion present. Pwats again lingering near 1 inch...quite high for this time of year. Furthermore tropical moisture arriving aloft always seems to enhance precip amounts. Thus will again trend pops toward 100 for Monday and monday night. Given our recent rains and ongoing flooding...the ongoing flood watch appear very warranted. We will not be surprised to see flood warnings needed on Monday and Monday Night. Given the expected precipitation will trend highs lower than the blends and lows warmer. On Tuesday the tropical flow will still be in place...but the models suggest a stronger and more organized upper level wave pushing through the plains states toward Indiana. A strong cold front and low pressure system will accompany this wave...and again ample moisture and plenty of forcing will be present. Thus will again trend pops near 100. Given the expected precip will trend temps at or below the builder blends. the wake of the front on Tuesday afternoon...strong winds will be expected given the strong pressure gradient in place. Gusts in the 30mph range will be attained. Strong cold air advection remains in play in the wake of the front on Tuesday night as the upper wave departs east and diverts the tropical flow aloft southeast. Forecast soundings show dry air within the column arriving ...along with some trapped cold air advection stratocu. Thus will trend toward mostly cloudy sky here and stick close to the blend on temperatures. High pressure an ridging is expected to build across the region on Wednesday. However the day will begin with the mid level ridge axis well west of Indiana and cyclonic flow still in place across the state. This is suggested to become more anticyclonic as the day progresses and cloud lead to decreasing cloudiness. Thus a dry day with decreasing clouds will be expected. && .LONG TERM /Wednesday night through Sunday/... Issued at 221 PM EST Sun Feb 10 2019 The long term starts out with dry weather and upper ridging moving across the area. By Thursday afternoon, though, a low pressure system swings out of the plains toward central Indiana, bringing a warm front across the area and possibly setting it up north of here. This will bring rain again to central Indiana, starting by Thursday night and remaining until the cold front moves through Friday afternoon/Friday night. After cold frontal passage, precipitation could change over to snow before dry air moves in to bring the precip to an end. Models are in better agreement on timing/placement with this late week system today so confidence is back to normal level for the long range. Expect above normal temperatures Thursday through Friday, with back to below normal on Saturday behind the front. && .AVIATION /Discussion for the 11/00z TAFs/... Issued at 624 PM EST Sun Feb 10 2019 Extremely poor flying conditions will persist throughout the TAF period, with LIFR or worse conditions dominating. Guidance is very insistent on widespread 1/2SM or less visibilities tonight in dense fog, along with widespread ceilings around 200 feet. There is a decent chance that airfields will drop below minima occasionally, and may stay there for extended periods. Winds will be less than 10KT through the period and frequently variable. Precipitation will be possible overnight but will likely be in the form of rain or drizzle...potentially freezing depending on temperatures. Any freezing precipitation will change over to liquid during the morning hours Monday. && .IND WATCHES/WARNINGS/ADVISORIES... Flood Watch from 1 AM EST Monday through Tuesday morning for INZ037-039-045>049-051>057-060>065-067>072. && $$ SYNOPSIS...Puma NEAR TERM...Puma SHORT TERM...Puma LONG TERM...TDUD AVIATION...Nield
Area Forecast Discussion
National Weather Service Marquette MI
549 PM EST Sun Feb 10 2019 .SHORT TERM...(This evening through Monday) Issued at 403 PM EST SUN FEB 10 2019 WV imagery and RAP analysis indicated a shortwave trough into the upper Mississippi Valley that supported an area of snow from eastern MN through WI and much of Upper Michigan. At the surface, light east winds prevailed between high pressure over northern Ontario and a trough from Kansas toward the southern Great Lakes. Tonight, Models and radar/satellite trends suggest that the snow will continue increase over Upper Michigan late this afternoon into this evening supported by deep layer 280k-295k isentropic lift and 850-600 fgen. As the supporting dynamics weaken and lift off to the northeast the snow should diminish by late this evening. Models consensus QPF values to around 0.10 inch along with snow/water ratios in the 15-20/1 support additional snowfall amounts of an inch or two. This is also consistent with the 1-1.5 g/Kg available in layer of max isentropic ascent. 850 mb temps around -15C with ese low level winds could bring some LES or lake enhanced snow into far north central Upper Michigan near Big Bay into the Keweenaw from KCMX northward. However, any additional snow amounts should be minimal, an inch or less. Monday, mid level ridging and subsidence building over the area should bring mainly dry weather. However, persistent east to ese low level winds could still generate some light LES over the north into the Keweenaw. Temps will recover toward seasonal averages with highs in the lower 20s. .LONG TERM...(Monday night through Sunday) Issued at 403 PM EST SUN FEB 10 2019 A shortwave will bring a deepening system into the region Mon night and Tue, keeping the surface to 850mb low on a track from southern Lake Michigan through Lake Huron. Models are in good agreement overall, but the latest CMC-NH run is an outlier as stronger and farther NW. This results in moderate to heavy snowfall moving in from the S late Mon night into Tue afternoon. Lighter snow will linger through the evening, and will then transition to NW wind LES Tue night into Wed. E to NE winds will enhance snowfall some over the N-central U.P. and also lead to blowing snow in areas exposed to those wind directions on Lake Superior and Lake Michigan. Total snowfall through Tue evening is currently expected to be 6-8" over all but the Keweenaw Peninsula which has 4-6". Much of that will fall in around 6 hours or possibly less late Mon night into Tue afternoon. Amounts may still change some as models have had some variability over the last couple of runs. Otherwise not looking at anything significantly impactful in the rest of the long term. Models are showing a significant winter storm in the region late in the week, but all are in agreement in keeping associated precip SE of the CWA. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 549 PM EST SUN FEB 10 2019 Snow spreading northward into Upper Michigan will bring IFR conditions into this evening at all sites. Conditions will improve to MVFR later as the light snow moves out. Will go briefly VFR at IWD at times late tonight and again Mon afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 403 PM EST SUN FEB 10 2019 A low pres system lifting from the southern Plains to the Great Lakes region next week may bring a period of east winds of 30 to 35 knots on Tue. Northerly winds into the 30-35 knot range are also expected Friday. Otherwise, periods of heavy freezing spray are expected into next week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Heavy Freezing Spray Warning until 7 PM EST /6 PM CST/ Monday for LSZ240>242-263. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Titus AVIATION...07 MARINE...JLB
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Monday Evening) Issued at 340 PM CST Sun Feb 10 2019 A broad swath of mid level moisture continues to lift northeast over the southern and central plains this afternoon. Associated with stout low level moisture in the form of thick stratus, temps have managed to stay a few degrees cooler, especially over east central areas where cloud cover has been dense with readings in the upper 30s. The initial cooler temps in the afternoon has translated into the evening with the trend from MOS guidance to be colder for lows than previous forecasts with readings in the upper 20s along the Interstate 70 corridor and northward. Meanwhile the latest runs of the HRRR and RAP are at or just above freezing, lending to some concern for precip type to start off as freezing drizzle initially after midnight. Expect the low level lift to increase over east central areas as the sfc low deepens eastward, lifting the warm front north. Initial drizzle may quickly switch to a mix of freezing drizzle, sleet, and snow towards sunrise and the morning rush hour. Given the timing of the precip and impact to the morning commute, have opted to issue a Winter Weather Advisory for the light freezing drizzle along the Interstate 70 corridor in east central Kansas through 15Z. Low visibilities are also a concern with the drizzle keeping readings between 1 and 3 miles. If the drizzle onset is slower however, dense fog may become more likely in east central Kansas underneath light winds and saturated sfc conditions. As the precip along and behind the front lifts into far northern Kansas, temps are progged to warm above freezing with light rain showers and drizzle expected for much of the CWA. Therefore, the Advisory plans to expire at 15Z. Further north towards the Nebraska border, the onset of frozen precip is closer to 12Z. Winter Weather Advisory goes into effect at this time and continues through Monday evening. Areas along and north of the highway 36 border are most likely to see periods of freezing drizzle mixed with light snow in the afternoon. Current position of the front and sfc temps near the Nebraska border may allow the wintry mix to linger longer into the afternoon. As the wave lifts out Monday evening, mid levels begin to saturate with optimal forcing for a mix of snow and/or freezing rain. As you head further south, qpf becomes lighter towards east central areas with snow and/or freezing drizzle possible through sunrise Tuesday. Winter Weather Advisory across far northern Kansas was kept Monday evening with forecast ice accumulations less than two tenths of an inch. For much of the CWA, a light glaze of ice is possible by Tuesday morning. .LONG TERM...(Tuesday through Sunday) Issued at 340 PM CST Sun Feb 10 2019 Upper ridging builds into the area Tuesday through Thursday with a quick warmup underneath gusty southerly winds. Warm downslope flow towards western Kansas with 925 mb temps increasing to around 10C is a decent signal for mild temps over northeast Kansas with both the GFS and NAM guidance hinting at upper 50s for highs Wednesday and Thursday. The next, progressive upper trough moves in Thursday evening, becoming closed off over southern Nebraska. Models are in better agreement on the timing and track of the system with there being a similar consensus of precip starting as rain before transitioning to snow towards Friday morning. Light accumulations may be possible, but this will likely change several days out. A few extended models are hinting at a much weaker short wave trough coming through over the weekend, otherwise temps are once again plummeting down into the single digits by Saturday morning with highs around 30 degrees. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 541 PM CST Sun Feb 10 2019 IFR to MVFR cigs are expected through 05Z with a transition to all IFR or LIFR for the rest of the period. Main concern will be the onset of drizzle and fog with ifr vsbys, then a transition to fzdz as temperatures cool around 10Z, temperatures should warm above freezing again by 14Z with drizzle and rain expected through the end of the forecast period. && .TOP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 3 AM to 9 AM CST Monday for KSZ021>024-026-036-038>040. Winter Weather Advisory from 6 AM Monday to midnight CST Monday night for KSZ008>012-020. && $$ SHORT TERM...Prieto LONG TERM...Prieto AVIATION...53