Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/02/21

Area Forecast Discussion
National Weather Service Binghamton NY
918 PM EST Fri Jan 1 2021 .SYNOPSIS... A wintry mix of freezing rain, sleet, and some snow will change over to rain late tonight and early Saturday morning as warmer air works in. A few rain and snow showers will linger into Saturday. Dry weather briefly returns Saturday night, then another storm will bring more snow Sunday and Sunday night. && .NEAR TERM /THROUGH SATURDAY/... 900 PM Update... Used HRRR 2m temperatures for surface temperatures in grids which fit the observations better than NBM. Then used RAP13 with the top down tool from BTV for the precipitation type. We will see a warm wedge aloft at 850 mb come through between 06z and 09z and this should lead to warming in the surface layer above freezing most places. In the meantime, there will be a dry slot coming thru between 9 and 11 pm but the HRRR does have another batch of precipitation coming through 06z-09z. Many areas especially Finger lakes and a lot of valley locations west of I-81 will see mostly rain. East of I-81 and especially Poconos/Catskills to Upper Mohawk likely will see a round of freezing rain. This could bring planar or flat ice totals to .5" in a few higher terrain sites in the Poconos/Catskills. Farther north toward the Mohawk Valley, these areas should see a period of freezing rain overnight. Since these areas have had more snow and sleet at this time, total ice accumulations will be lower up there than in our northeast PA/Catskills higher terrain areas. We have received several reports of close to .2" of flat ice in northeast PA and the southern tier. So the additional ice puts many areas around .3" or so. Of course the valleys have less for the most part. A quick look at the power outage maps shows very little so this event looks to have mainly a travel impacts so far and we don`t expect enough additional radial ice to significantly impact power. Expanded the winter weather advisory for areas west of I-81 where we feel many higher terrain areas will still be close to freezing as next batch of light precipitation arrives. 600 PM Update... Looking at surface observations and radar mosaic imagery there was a large area of temperatures from the upper 20s to lower 30s from central NY/northeast PA south into the PA mountains and just east to northern VA and western MD. Widespread freezing rain was reported in much of northern and central PA into south central PA and down into the central Appalachians and points just to the east. Also there was widespread freezing rain in south central NY and the Finger Lakes. Some sleet and snow was developing in north central NY to Catskills initially, as expected with colder air aloft in place at the onset. The surface flow was easterly with dewpoints from the low to mid 20s in eastern NY to upper 20s to near 30 down into central and south central PA. RAP analysis data initialized at 23z shows a wedge of colder air down the Appalachian mountains in the typical cold air damming fashion. 850 mb temperatures range from 4-5C in northern WV to 1-3C farther north into south central/northeast PA. Temperatures at 850 mb drop below freezing across much of eastern and north central NY where we expect more snow initially. Based on the temperatures and still some drier air advecting into northeast PA and central NY at the surface we have increased ice accumulation (planar) a tad. Basically we have much of our forecast area between .1 and .25" with locally above .25" in our higher terrain of Catskills and Poconos. Our deeper valleys and along the Finger Lakes we have less than .1". As for impacts, we don`t expect any widespread power outages, especially since we are forecasting planar ice. Warmer air eventually will advect in aloft and mix down to the surface with the precipitation later this evening changing freezing rain to all rain. The hold outs will be from the upper Mohawk Valley to Catskills/Poconos where the cold air loves to hang tough. These areas will see more freezing rain. 330 PM Update... An upper level low is currently rotating over Missouri and southern IL, with strong southerly flow out ahead of it is advecting increasingly warm and moist air into the region. Precipitation associated with the warm front is already moving into our northeast PA zones at this time, but nailing down the precipitation type is proving difficult with very nearly everything being reported across northern PA so far. Surface temperatures hover in the lower to mid 30s with dewpoints in the 20s. With the onset of precipitation, sites more to our southwest have been able to wet bulb down below freezing. Given a fairly warm airmass aloft, the primary concern is for sleet and freezing rain. Indeed, many locations are already reporting freezing rain. However, even aloft, temperatures have been able to cool sufficiently in some spots to allow for more of a snow profile. A nearby NUCAPS sounding from earlier this afternoon showed a fairly cool, moist sounding that would indicate mainly snow or a rain/snow mix. So, with the onset, will keep in a chance for some flakes, but then a rapid change over to sleet and finally freezing rain is expected pretty much within an hour of the onset for most locations as precipitation continues to spread northward. This may result in some light snow/sleet totals below an inch over this evening. Into the night, most of the area should see a change over to rain as surface temperatures slowly warm through the 30s. However, the higher elevations of the Catskills and Poconos, as well as portions of Steuben county, may be able to hang on to freezing rain a bit longer. Additionally, northern Oneida county may be able to see snow and sleet well into the night before a change mainly over to freezing rain after midnight. This could yield higher snow totals there up to 2 to 3 inches overnight. Precipitation lifts northeast out of the area into Saturday as the low moves moves northeast towards southern Ontario/Quebec. Cooling temperatures aloft will allow for a change back over to rain or a rain/snow mix where precipitation can linger into Saturday morning. This would be mainly over northern Oneida county. Storm total QPF generally around a half to three quarters of an inch is expected. With much of the area turning over to freezing rain overnight, at least a light glaze of ice is expected area-wide, but heavier totals up to a quarter inch are not out of the question especially across the Catskills and Poconos. Temperatures rise up into the mid and upper 30s across central NY Saturday, and into the upper 30s and lower 40s in northeast PA. Winds shifting to the northwest will increase to around 10 to 15 mph, and gust as high as 20 mph particularly over the higher elevations. This may be something to keep an eye on, considering any lingering ice accumulations. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... 220 PM Update... High pressure filtering across the region from the Great Lakes will partially clear skies and allow for a cold overnight period with lows dipping well into the 20s on Saturday night. On Sunday, a moderately strong upper level low will transition from the Ohio Valley into Western New York by evening. This feature will transfer energy to a newly developing surface low off the Virgina capes. This system will track northeastward spreading snow into NY and PA from late morning through Sunday evening. The best forcing looks to be over NEPA closest to the track of the new low and along the base of the upper trof where accumulations should be highest. A marginal, near isothermal profile at times indicates a chance for some mixed precipitation for NEPA. Can`t totally rule out portions of the Southern Tier and Catskills for a little sleet, but overall, model soundings suggest this as a snow event along with some possible rain in the valleys as temperatures breech the mid 30s during the afternoon. Snow accumulations of two to four inches are expected over the higher terrain of NE Pennsylvania and the Catskills of NY. Expect one to three inches along the Southern Tier and lesser amounts to the north. Steady snow will pull out on Sunday evening and diminish to scattered snow showers through the night. Quieter weather expected by Monday morning. && .LONG TERM /MONDAY THROUGH FRIDAY/... Quiet weather will prevail between Monday and Wednesday as weak high pressure moves through the region. A few flurries or light snow showers are possible Monday near the lakes. Light rain or snow showers are possible Thursday as milder air streams into NY and PA. Afternoon temperatures will be mainly in the middle 30s through the middle of the week. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... 700 pm update... Precipitation has moved in and has largely started as FZRA and PL for all terminals but RME where enough cold air is in place for snow. As the LLJ increases aloft, warm air moves in and will transition all Ptypes to FZRA and eventually RA as the surface temperatures warm above freezing from S to N. LLWS has been put in at all terminals to account for the LLJ. Ceilings are expected to fall to IFR conditions for most of the night. As the low moves off to the NE, moist NW flow keeps low clouds around tomorrow but ceilings look to rise to MVFR and Fuel Alternate conditions. There is a chance that AVP will be able to get to VFR conditions late tomorrow as downsloping into the Wyoming Valley helps to dry out the airmass. Outlook... Saturday night..High pressure with some . Sunday...Occasional restrictions possible in rain and snow showers. Monday through Wednesday...Mainly VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Winter Weather Advisory until 7 AM EST Saturday for PAZ040-048- 072. Winter Weather Advisory until 5 AM EST Saturday for PAZ038-039- 043-044-047. NY...Winter Weather Advisory until 7 AM EST Saturday for NYZ018-036- 044>046-057-062. Winter Weather Advisory until 5 AM EST Saturday for NYZ015>017- 022>025-055-056. Winter Weather Advisory until 10 AM EST Saturday for NYZ009- 037. && $$ SYNOPSIS...HLC NEAR TERM...DJN/HLC SHORT TERM...JAB LONG TERM...DJP AVIATION...AJG/HLC
Area Forecast Discussion...Updated
National Weather Service Peachtree City GA
950 PM EST Fri Jan 1 2021 .Update... No big changes. Rain continues to move into east central GA. Rain has ended for the night over northwest and the north half of the area should be dry until rain moves back Saturday afternoon. 41 .Previous... .SHORT TERM /Tonight through Saturday Night/... A prefrontal line of showers and a few embedded isolated thunderstorms continues to push eastward across the forecast area this afternoon. The approaching cold front extends southward across central Alabama from a surface low currently over the mid- Mississippi Valley. Meanwhile, the last vestiges of a surface wedge are slowly being scoured out of far northeast Georgia as the surface front lifts northward. As far as the severe threat is concerned, the limiting factor continues to be low surface instability despite plentiful shear. With that said, through the reminder of the afternoon, a marginal severe risk will remain given a strong low- level jet and increasing low-level warm advection along the warm front. Any thunderstorms that continue to be able to strengthen in this zone would bring an isolated damaging wind gust or brief spin- up tornado threat. Otherwise, while PWs are elevated, quick storm motion has served to limit overall precipitation accumulations. However, areas where precipitation has had more of an opportunity to train from this morning through this afternoon have received higher totals, particularly across northeast Georgia. Localized minor hydrological issues remain possible in these locations through this evening by which time the rain tapers off. By Saturday morning, the cold front will have made progress into eastern/central portions of the CWA where it will stall. The morning will bring a brief respite of drier conditions across much of the area, with the exception of perhaps the far southeastern CWA. Dry weather will be short-lived, though, as a shortwave lifts northeast out of Texas into the ArkLaTex. This will induce the development of a low along the front, and moisture will quickly surge back northward into the area. Thus, PoPs will be on a quick increase from tomorrow afternoon into tomorrow night, particularly across the southeastern half of the area. No strong or severe thunderstorms are expected given very weak instability. However, heavy rainfall totals are possible in southeastern portions of the CWA, particularly overnight tomorrow night where totals could approach 2". These totals could be sufficient for localized minor hydro concerns, though significant flooding issues are not expected. RW .LONG TERM /Sunday through Friday/... The long term period will be much quieter than the short term as the forecast area returns to mostly clear and dry, diurnal conditions following a cold front that will drop PWATS below 0.5 inches through at least Wednesday night. In the meantime, surface high pressure will take hold with upper-level ridging aloft allowing afternoon high temps to climb into the 50s and low 60s each day for the first half of the week. Afterwards, another synoptic trough will once again set up over the eastern CONUS with a storm system expected sometime between Thursday and Friday night. Models are beginning to come into alignment but there are still major discrepancies as to the timing of this frontal system, up to 18 hours in some cases, but improving from timing differences during the previous shift. There will also be an chance for some light snow showers for North Georgia with some rap around moisture Thursday night into Friday morning, but we`ll have to see if colder temperatures continue to hang around with the precip as the week progresses. Thiem && .AVIATION... 00Z Update... Showers have moved east of the taf sites...except KMCN will have showers until around 02z. IFR ceilings should remain largely the rule overnight...though some brief...patchy improvement to MVFR or even VFR remain possible at times. More persistent improvement to VFR is more likely by 10-12z Saturday. Winds will remain SSW 4 to 7 kts overnight...becoming west by 10z 8 to 10kts. //ATL Confidence...00Z Update... Low to medium confidence on cigs through tonight. Medium to High confidence on winds and precip timing. 41 && .PRELIMINARY POINT TEMPS/POPS... Athens 52 66 45 55 / 60 50 90 5 Atlanta 50 63 42 51 / 30 40 70 5 Blairsville 45 62 39 46 / 50 10 60 10 Cartersville 46 62 40 51 / 30 20 50 5 Columbus 53 66 43 55 / 30 70 70 5 Gainesville 49 63 44 51 / 50 30 80 5 Macon 58 67 46 59 / 60 80 90 5 Rome 46 62 40 51 / 20 10 40 5 Peachtree City 49 66 41 54 / 30 50 60 5 Vidalia 65 70 54 62 / 70 90 90 5 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...41 LONG TERM....Thiem AVIATION...41
Area Forecast Discussion
National Weather Service Jacksonville FL
936 PM EST Fri Jan 1 2021 ...WAVES OF HEAVY DOWNPOURS TO IMPACT PORTIONS OF INLAND SOUTHEAST GA THROUGH SATURDAY NIGHT... .UPDATE... Late evening surface analysis depicts complex low pressure (1007 millibars) over the Ohio and Tennessee Valleys, with a decelerating cold front stretching southward from this storm system to the FL panhandle and extending into the central Gulf of Mexico. Strong high pressure (1031 millibars) over New England was keeping a wedge of cool air over the Carolinas and the southern Appalachians, with southerly low level flow to the south of this wedge over our area. Aloft...deep-layered ridging was centered over the Bahamas, while a potent shortwave trough was accelerating east-northeastward across the lower Great Lakes region, with another potent shortwave trough emerging from the Desert Southwest into west Texas. A ribbon of deep moisture remains in place ahead of the upstream cold front over inland southeast GA, with latest RAP analysis indicating PWAT values of 1.7-1.9 inches for locations west and northwest of Waycross. Within this corridor of deep moisture, heavy downpours streamed over the Ocmulgee and western Altamaha Rivers earlier this evening, and another wave of downpours currently moving onshore along the FL Big Bend coast was poised to race northeastward towards these areas after midnight. Mid and high altitude cloud cover otherwise blankets our region, with some low stratus hugging the coast from Amelia Island / Fernandina Beach northward. Temperatures at 02Z were generally in the 65-70 degree range, with unseasonably high dewpoints in the mid to upper 60s prevailing area-wide. Potent shortwave troughing accelerating northeastward through the lower Great Lakes states will continue to move away from our region overnight, resulting in the frontal boundary to the west of our region stalling overnight. Another wave of heavy downpours will quickly move northeastward across inland southeast GA after midnight, providing another 0.25 to 0.5 inches of rainfall for areas west and northwest of Waycross that received up to an inch of rain this evening. Meanwhile, the large trough aloft entering west Texas this evening will pivot northeastward across the Ozarks by Saturday afternoon and will then accelerate across the Tennessee Valley on Saturday night. This feature will create a highly diffluent flow pattern aloft over the Gulf of Mexico, resulting in a wave of low pressure developing along the stalled frontal boundary towards noon on Saturday. The increasingly diffluent flow aloft will continue to send waves of convection and downpours from the Gulf of Mexico northeastward across the FL Big Bend region and into inland portions of southeast GA through Saturday night, with only a few showers possible elsewhere as ridging aloft only slowly slides eastward by late Saturday. Lows tonight will only fall to the low and mid 60s area-wide, with highs on Saturday remaining in the low to mid 70s for inland southeast GA and the upper 70s to lower 80s elsewhere. && .MARINE... Areas of dense sea fog will remain possible tonight through early Sunday afternoon over the near shore waters adjacent to southeast GA and possibly the waters surrounding Amelia Island. Small Craft should continue to Exercise Caution if venturing to the offshore waters, where southerly winds will be sustained at 15-20 knots through at least midnight and 4-6 foot seas will prevail through Sunday. Otherwise, a cold front stretching from the Tennessee Valley southward to the central Gulf of Mexico will stall to the west of the Georgia waters on Saturday as low pressure develops along the front over the Gulf of Mexico and lifts northward. This low pressure center will then accelerate northeastward while slowly strengthening on Saturday night, propelling the frontal boundary eastward across our local waters during the predawn and early morning hours on Sunday, accompanied by showers. High pressure will then build along the northern Gulf coast region early next week, with prevailing offshore and gradually diminishing seas expected through Tuesday. Rip Currents: A moderate risk of rip currents will continue at area beaches on Saturday, with low risks expected Sunday and early next week. && .HYDROLOGY... Some of the 00Z Sat guidance is indicating the potential for 2-4 inches of additional rainfall for locations west and northwest of Waycross, where a Flood Watch or even a Flash Flood Watch may be considered for Saturday and Saturday night as downpours continue to train over increasingly saturated soils, particularly for locations along the Ocmulgee and Altamaha Rivers. Rises along these rivers are likely later this weekend and into next week. && .PREV DISCUSSION [704 PM EST]... .NEAR TERM [Through Tonight]... Flow aloft will continue to veer as shortwave energy shoves the front and associated moisture into the region late today and tonight. Current POPs look good with minor adjustments, with scattered showers moving into southeast GA this afternoon and better rain chances into the evening and overnight hours. A few pop-up showers possible this aftn over northeast FL near convergent lines. Enough instability with MUCAPEs near 300-700 will support a slight chance of thunderstorms late today and tonight over inland southeast GA. A risk of an isolated strong to severe storm remains possible this evening and overnight over inland southeast GA northwest of a line from Baxley to Pearson where bulk shear values of 40 kt are noted. Highs today well above normal in the upper 70s to lower 80s, with near record highs over northeast FL and probably only 2-3 deg shy. Sfc winds breezy at times from the south near 15 mph and gusty. .SHORT TERM [Saturday Through Sunday Night]... The slow moving cold front to our west is expected to become reinvigorated Saturday afternoon as an upper level +PV anomaly digs into the Southern Plains and develops a surface low along the front in the north-central Gulf waters. The upper level low will then lift into the OH Valley Saturday night, dragging the front eastward across the southeastern US. Scattered showers and isolated thunderstorms will continue Saturday with the highest chances/coverage over inland SE GA, but the majority of the precipitation is expected to fall Saturday night. Heavy rain is possible Saturday and Saturday night, mostly across southeast Georgia. Rainfall amounts of 1-2.5 inches are forecast, and locally higher amounts of 3-4 inches are possible which could lead to localized ponding and street flooding. WPC has a slight risk of excessive rainfall for tomorrow over a portion of Jeff Davis, Coffee, and Atkinson counties in SE GA. In addition to the heavy rainfall threat, a portion of the low level jet may still line up over our inland GA counties and deep layer shear of around 50 knots suggests some of the storms that develop Sat/Sat night could produce some strong to severe wind gusts (40-60 mph). Even outside of storms, breezy winds occasionally gusting to around 20-30 mph will be possible as we`ve seen today. The upper low driving this system will continue to lift northeastward into the Great Lakes Sunday and with the main energy driving the system lifting so far away, the front will lose much of its steam as it continues to exit our area of responsibility Sunday morning. Behind the front, cooler, drier air will begin to filter into the region. After several days with highs in the upper 70s-low 80s, Sunday will see highs struggling to reach 60 over inland SE GA and 70 in NE FL. Lows Sunday night will dip into the mid-upper 30s in the Suwannee Valley and frost is possible early Monday morning. .LONG TERM [Monday Through Friday]... Low level ridging will build in over the southeast early next week in the wake of the cold front. Around mid-week another upper low will move into the Plains and develop the next cold front to approach the region. As this developing system pushes the low level ridge offshore around Wed/Thu, onshore flow will begin to return some moisture and low end rain chances ahead of the next front could return Thursday, with the front crossing through the area around Friday. Temperatures next week should be near normal for this time of year- peaking in the 60s in the afternoons and dipping to the upper 30s/low 40s in the mornings. .AVIATION... [Through 00Z Sunday] VFR conditions will prevail through at least 06Z at the regional terminals. Brief light showers will be possible at SSI and JAX through around 04Z, potentially producing ceilings around 4,000 feet. Otherwise, sea fog will possibly set in at SSI after 06Z, with higher probabilities for IFR conditions occurring after 09Z, followed by the potential for a brief period of LIFR ceilings around 300-400 feet towards 12Z. IFR ceilings will likely prevail at SSI through around 18Z, with ceilings then lifting to MVFR around 1,500 feet. Elsewhere, MVFR ceilings of 1,200-2,500 feet will likely develop shortly after 12Z, with brief periods of IFR to MVFR ceilings at GNV after 09Z. Confidence was too low to include IFR conditions at GNV at this time. Showers may begin to impact SSI after 16Z. Southerly low level winds will increase overnight, with speeds around 30-35 knots expected at the regional terminals towards 09Z, possibly reaching marginal low level wind shear criteria at the regional terminals during the predawn and early morning hours on Saturday as surface winds remain sustained at or below 5 knots. Sustained southerly surface winds will then increase to near 10 knots after 15Z. && .PRELIMINARY POINT TEMPS/POPS... AMG 66 72 54 62 38 / 80 90 80 0 0 SSI 61 71 59 67 42 / 20 30 60 20 0 JAX 64 80 61 70 41 / 20 20 50 20 0 SGJ 65 79 63 71 44 / 10 20 30 30 0 GNV 63 80 62 69 39 / 10 20 60 20 0 OCF 63 81 62 72 41 / 10 10 50 20 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. &&
Area Forecast Discussion
National Weather Service North Platte NE
525 PM CST Fri Jan 1 2021 .SHORT TERM...(This evening through Saturday night) Issued at 331 PM CST Fri Jan 1 2021 The RAP model shows dry air moving in tonight and precipitable water will fall to around 0.20 inches across western Nebraska by morning. This should set the stage for fairly strong radiational cooling. Winds aloft at h850mb are 15kts supporting light sfc winds. The cooler NAM and ECM guidance is in place for lows in the teens and single digits. The SREF suggests the potential for valley fog tonight and patchy fog is in place across parts of ncntl and swrn Nebraska. Temperatures aloft warm a few degrees Saturday. The bias corrected guidance blend suggested highs in the mid and upper 40s. The temperature forecast uses this blend but marks down temperatures a couple of degrees for existing snow cover. The models suggest full sun conditions. A weak cold front will work through western and north central Nebraska Saturday night. This should produce a period of cloudiness according to the model consensus but still potentially mostly clear throughout the night. The frontal boundary should disrupt the nighttime cooling cycle and the bias corrected guidance blend suggested lows in the upper teens to lower 20s. .LONG TERM...(Sunday through Friday) Issued at 331 PM CST Fri Jan 1 2021 The models are in good agreement projecting a warming trend Sunday through Tuesday followed by a strong cold front Wednesday with cold weather continuing Thursday. The ECM is the strongest and produces about a 1/4 inches of liquid which would be rain changing to snow. The ECM ensemble is more relaxed with around 1/10 of an inch or less liquid which is similar to the GFS and it`s ensemble. The origin of the disturbance is currently across the Aleutians so there are many days and miles before this system will affect Nebraska. For this forecast, just slight chance POPs are in place. Otherwise, temperatures around 5C at h850mb until Wednesday should easily support highs in the 40s to around 50. The cold front will send the h850mb temperatures to around -5C which would support highs around freezing. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 519 PM CST Fri Jan 1 2021 VFR conditions expected to prevail for the next 24 hours. Clear skies and light west/southwest winds are expected, with no impacts to aviation anticipated. && .HYDROLOGY... Issued at 331 PM CST Fri Jan 1 2021 Time-lapse camera shots from the NDOR clearly show floodwater deepening on accretion ground in the primary flood plain of the North Platte river near Lewellen. A flood advisory continues in place for the foreseeable future. Overnight lows in the single digits appear to have been sufficient to create the necessary ice for ice-jamming. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Brown HYDROLOGY...CDC
Area Forecast Discussion
National Weather Service Louisville KY
836 PM EST Fri Jan 1 2021 .Forecast Update... Issued at 835 PM EST Fri Jan 1 2021 Winds still are gusting in the 25-35 mph range now, below threshold for a wind allowed that product to expire earlier this hour. Surface low pressure now is analyzed to our north and east, and measurable precip has shifted into eastern KY. It still looks like we`ll get some patches of drizzle overnight and into Saturday morning. Have updated the forecast to remove the headline and trend toward latest temperature/wind guidance. && .Short Term...(This evening through Saturday) Issued at 311 PM EST Fri Jan 1 2021 ...Gusty Winds & A Few Strong Showers or Storms Possible... The warm sector has quickly become established over most of our region at this hour as KY Mesonet obs show low 70s readings across the southern half of central KY at this hour. The 60 degree line has almost made it to the Ohio River, and will continue advecting northward on the aid of good heating, and with some advection ahead of a surface low currently over west central KY. We`ve seen some deeper mixing where clouds have cleared out in the this dry slot, and even a couple of gusts just over 40 mph. Will go ahead with a short Wind Advisory in anticipation of a few more 40+ gusts popping up. We do have another couple/few hours of the 40-50 knot low level jet core over our warm sector, and sounding show low level thermal profiles capable of tapping into that higher momentum air aloft, so can`t rule out the stronger gusts developing. Speaking of stronger gusts, we also have the threat of some low topped convection for the afternoon and early evening. Have started to see a broken line of showers develop across our NW CWA, just ahead of a convergent surface feature that will push into our north central CWA over the next 1 to 2 hours. As this occurs, there should be better alignment of enough low level convergence and the instability axis that is now ranging around 500-750 J/KG of near surface based CAPE across south central KY. The HRRR has suggested now for a couple of consistent runs (along with the 12z NAM 12 solution) that scattered to numerous low topped showers or storms will develop across north central KY and then move toward the Bluegrass region into the early evening hours. If these storms do get a bit better organized, then isolated instances of stronger gusty winds will be on the table. At this point, think the threat for any tornadic activity would be a bit lower right ahead of the front as low level hodographs are a little less favorable, but still a few rotating storms would be possible in this shear environment. Again, all of this is conditional upon the convection getting going better as the HRRR would suggest. A look at soundings does show a limiting factor to the depth of the convective potential around 700mb, which will likely be a limiting factor for deeper convection and the ultimate reason why there isn`t more of a severe risk depicted by SPC. Nevertheless, higher momentum air aloft could be brought down with any more robust updrafts. .Long Term...(Saturday night through Friday) Issued at 201 PM EST Fri Jan 1 2021 Widespread precipitation will move into the region tomorrow night as a negatively tilted shortwave trough swings into the lower Ohio Valley. Temperature profiles generally support an all liquid scenario across most of central KY, but some diagnostic and ensemble model members highlight temperatures getting cold enough to support snow across southern IN. In the colder model scenarios, the vast majority of snowfall accumulations are minor (<1"). The trough should lift northeast of the region by Sunday morning, though lingering low level moisture could result in periods of drizzle and clouds through a good portion of the day. Most of early next week will feature dry weather as an upper level ridge advances from the west and keeps the region confined to dry NW flow aloft. It`s not until late Wednesday into Thursday that the next chance of precipitation arrives ahead of an upper level low. Long range guidance varies on the timing and evolution of this low over our region, which isn`t too surprising considering it`s +150 hours out. Given the variability, will keep the PoP chances low, but think at some point in the late-week period several locations will have a decent shot at observing precipitation. && .Aviation...(00Z TAF Issuance) Issued at 630 PM EST Fri Jan 1 2021 Still have a few wind gusts at the terminals this evening, as a complex low pressure system crosses the area. One lobe of that surface low is roughly north of FFT now and continuing northeastward. Low clouds will fill in overnight, as winds start to die down and become variable. Subsidence moving overhead likely will force some drizzle to develop withing the LIFR to IFR cigs expected by daybreak in the I-64 terminals. BWG could get some as well around daybreak, but at the least they should have less than 2 kft MVFR by then. Conditions will be slow to improve Saturday. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...RJS Short Term...BJS Long Term...DM Aviation...RJS
Updated for 00Z Aviation Forecast Discussion below.

&& .PREV DISCUSSION... /issued 336 PM CST Fri Jan 1 2021/ DISCUSSION... A blustery New Year`s Day across the Mid-South. Latest surface analysis places two areas of low pressure north of the Mid-South. One is just east of Saint Louis, Missouri and another low near Fort Knox, Kentucky. This has kept a stout pressure gradient over the region, with gusts to 30 mph throughout the day. Both areas of low pressure are expected to lift north away from the Mid-South over the next several hours, with winds relaxing by this evening. A cold front currently extends southward through Centerville, Tennessee from the latter low pressure system. Temperatures have generally fallen throughout the day as cold air has filtered in behind the front. The exception was near the Tennessee River, where temperatures rose into the upper 60s under mostly sunny skies in the dry slot. The rest of the area is in the mid to upper 40s under overcast skies. Expect stratus to remain over the region overnight, keeping air temperatures from falling too much. Lows will bottom out in the mid to upper 30s due to moderate CAA. A clipper type system will push through the region tomorrow afternoon. This will keep abundant cloud cover over the region along with the chance for light rain along and north of I-40 Saturday afternoon and early evening. QPF totals look to remain light, less than a tenth of an inch, as temperatures fall into the upper 30s tomorrow evening. Soundings suggest that a light rain snow mix could occur in the Missouri Bootheel as the system lifts north tomorrow night. No impacts are expected due to warm surface temps. Clear skies will finally return to the Mid-South on Sunday as surface high pressure builds in from the west. Expect seasonal highs with readings in the upper 40s. Dry and sunny conditions will persist across the region through Wednesday as high pressure remains over the region. Highs will creep into the mid to upper 50s each day. Rain will return to the Mid-South Wednesday night into Thursday as a low pressure system moves across the Lower Mississippi Valley through late week. AC3 && .AVIATION... 00Z TAFs A challenging ceiling forecast, with a moist, relatively well- mixed layer below FL030, as depicted on the RAP and NAM Bufr soundings. An upstream upper low will lift out of the southern plains into the Ozarks late tonight and Saturday. Scattered -RA and patchy -DZ ahead of the low will drive a marginal IFR potential, mainly after 12Z. SREF depicts IFR potential at MEM peaking at 30% 15Z, decreasing to around 10 percent at 21Z. 00Z TAF didn`t depart much from this scenario. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service New York NY
943 PM EST Fri Jan 1 2021 .SYNOPSIS... A warm front will approach from the south and enter the area late tonight, followed quickly by a cold front from the west. The low will move into New England on Saturday, followed by high pressure building from the west Saturday into Saturday night. Another low will develop to the south Sunday and pass to the east on Monday, followed by high pressure building from the west through the end of next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Parent low pressure tracking towards Lake Erie with secondary development occurring along warm front to our south across the Delmarva. The steadiest precipitation has been generally across the southern half of the region. There is a bit of a dry slow between precip across upstate NY and the precip closer to the warm front. HRRR and the latest NAM show this should fill in a bit over the next few hours. Freezing rain has been observed across the NW interior with several locations in Orange county measuring under a tenth of an inch of ice accretion. Early sleet reports were brief and at the onset. Precip has struggled to make into across eastern CT due to earlier surface ridging, but there could be some sleet at the onset as well. Have left the Winter Weather Advisory alone for now, although it is possible portions of eastern CT can be removed earlier as temperatures have been running a bit warmer. If steadier precip can develop here, then some wet bulbing may occur allowing for more widespread freezing rain. Closer to the coast, plain rain, moderate at times continues. The overall precip shield should advance eastward early Saturday morning with drying conditions from west to east just before day break. The secondary low may track along the warm front across Long Island around day break. This will allow temps at the coast to rise, and may reach the lower 50s across eastern Long Island by daybreak. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... Gusty west winds (25 to 35 mph) will develop behind the system on Saturday as a secondary low deepens off the New England coast. Skies will also clear in the afternoon as high pressure builds in from the west. Deep mixing, weak CAA, and downslope flow will result in temps above seasonable (upper 40s to mid 50s). High pressure builds across the area Saturday night with lows 30-35 invof NYC and in the 20s elsewhere. && .LONG TERM /SUNDAY THROUGH FRIDAY/... The main fcst challenge is the Sun/Mon sys. Low pres is progged to deepen off the Delmarva on Sun, then track e of Cape Cod by 00z Tue. The low is not progged to be very deep, around 995 mb in the GFS at 00Z Tue, so the storm may not get wrapped up until it is past the area. The track is somewhere invof the benchmark, with the ECMWF e of the GFS. If there was an arctic airmass in place, it would be a widespread snowfall event, but that is not the case. The challenge will therefore once again be where the rain/snow line sets up and snowfall intensity, which will lead to eventual accums. Best spots for all snow across the interior, and this is reflected in the storm total snowfall. If this sys maintains an ern track however, the heaviest pcpn may fall closer to the coast, mainly in the form of rain. If the low intensifies a little quicker, there could be better chances for snow closer to the coast. A model consensus was used for the fcst attm, with thicknesses derived from the NAM and GFS. Please see the storm total graphic for fcst accums. Fair wx is then fcst Tue thru Fri with the area wedged between high pres to the west, and low pres to the east. The models show a hint of sct-isold shsn/shra late Tue into Wed with the passage of an h5 low, but the NBM pops were dry so did not include in the fcst this far out. There is a low pres sys modeled to pass south of the region during the end of the week. Both the ECMWF and GFS have it. The fcst has been kept dry consistent with the current progs, but it will be something to watch. Temps on Sun and Mon close to a raw model consensus for the passing low, then close to the NBM thereafter. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Low pressure and its associated frontal system approach from the south tonight. The low pressure system moves across the region Saturday morning, moving off the New England coast Saturday afternoon. High pressure builds from the west Saturday evening. NE-E winds generally 10 kt or less tonight. Winds will shift to the W-SW and increase Saturday morning with gusts 25-30 kt likely late morning into the afternoon. Winds then become NW and slowly weaken in the evening. Conditions continue to deteriorate in mainly light rain, but moderate rain is possible at times. At SWF, -FZRAPL is likely, becoming plain rain 05-07z. A glaze of FZRA is likely at SWF tonight before becoming plain rain. Flight categories will continue to lower to IFR through 05z. Widespread LIFR is forecast after midnight through around daybreak Saturday before lifting to MVFR then VFR through the morning. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments likely for flight categories through early Saturday morning. Timing of wind shift and gusts Saturday morning may be off 1-3 hours. .OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY... .Saturday Night...VFR. NW Winds diminish. .Sunday-Sunday Night...IFR or lower developing in rain for city/coastal terminals and snow inland. NE wind gusts 20-25kt near coast late Sunday into Sunday night. .Monday...Becoming VFR. NW gusts 15-20 kt possible. .Tuesday-Wednesday...VFR. NW gusts 20-25kt possible. && .MARINE... SCA conds should develop on the ocean E of Moriches tonight in SE flow between departing high pressure and an approaching warm front/weak low. A cold front should quickly follow by daybreak Sat, with minimal 35-kt gales on the ocean E of Fire Island Inlet by late morning or afternoon, and SCA conds on all other waters as winds gust to 25-30 kt. SCA conds with W winds gusting 25-30 kt should continue on the ocean/bays/ern Sound into Sat evening, then ramp down briefly overnight Sat night. A SCA will likely be needed Sun and Mon on the ocean. Low prob for gale force gusts. A SCA is possible for the remaining waters. Winds and seas look to remain at mrgnl SCA lvls on the ocean Tue thru Thu, with the protected waters blw criteria. && .HYDROLOGY... No hydrologic impacts are expected with one half to three quarters of inch of liquid equivalent through Saturday morning. Potential for another 1/2 to 1 inch of rain Sunday into Sunday Night. Hydrologic impacts look minor at worst at this time. && .TIDES/COASTAL FLOODING... Potential for minor coastal flood impacts during the Sun morning/aft and night high tides with E/NE winds associated with a coastal low passing to the south and east. As little as 1 1/2 to 2 ft of surge needed to reach minor flood levels during the Sunday daytime high tides. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Winter Weather Advisory until 4 AM EST Saturday for CTZ005>008. NY...Winter Weather Advisory until 4 AM EST Saturday for NYZ068>070. Winter Weather Advisory until 7 AM EST Saturday for NYZ067. NJ...Winter Weather Advisory until 4 AM EST Saturday for NJZ002. MARINE...Small Craft Advisory from 9 AM to 7 PM EST Saturday for ANZ335- 338. Small Craft Advisory from 9 AM Saturday to midnight EST Saturday night for ANZ330-340-345. Small Craft Advisory from 6 AM to noon EST Saturday for ANZ353. Gale Warning from noon to 7 PM EST Saturday for ANZ353. Small Craft Advisory from 6 AM Saturday to midnight EST Saturday night for ANZ355. Small Craft Advisory until 6 AM EST Saturday for ANZ350. Gale Warning from 6 AM to 7 PM EST Saturday for ANZ350. && $$ SYNOPSIS...JMC/BG NEAR TERM...BG/DS SHORT TERM...BG LONG TERM...JMC AVIATION...DS MARINE...JMC/BG HYDROLOGY...JMC/BG TIDES/COASTAL FLOODING...