John1122 Posted January 21, 2015 Share Posted January 21, 2015 Well, it's within 72 hours of beginning and modeling is looking more and more robust for potential snow somewhere in the Great Valley region. Right now 40 North and Plateau west look to be in the sweet spot with several runs in a row of the GFS really hammering those areas into Southern Kentucky. As of now, all major models are on board with the storm and are showing a near perfect track for widespread snow across our region. The main issue, as always, will be warm nosing causing boundary temp issues. This looks especially likely for the Eastern Valley, from Chattanooga to Knoxville. If the boundary temps work out, this looks like it could be a nice one. It's also somewhat shown that the new GFS has the same NW trend that the old GFS exhibited. Here are some clown maps from tonights runs. 00z GFS Through 90 hours on top, then the GGEM that Jags already posted in the pattern thread. Link to comment Share on other sites More sharing options...
John1122 Posted January 21, 2015 Author Share Posted January 21, 2015 MRX says a couple inches for the Plateau and Mountains on the back side of this system in the deformation band come Friday night into Saturday. Very bullish on the Clipper following in the wake of this system. Link to comment Share on other sites More sharing options...
John1122 Posted January 21, 2015 Author Share Posted January 21, 2015 06z NAM 12k out to 84. Less bullish than the 00z, which was epic for the Western Half of the Valley. This is still not too bad, widespread 1-3 inches it appears. Link to comment Share on other sites More sharing options...
Stovepipe Posted January 21, 2015 Share Posted January 21, 2015 A few meteograms: I'd like to see middle and west reel this one in. You folks are over due. Link to comment Share on other sites More sharing options...
tnweathernut Posted January 21, 2015 Share Posted January 21, 2015 A few meteograms: I'd like to see middle and west reel this one in. You folks are over due. Me too. I have a buddy just north of Nashville that has been giving me all kinds of grief about it not being able to snow in mid TN anymore (due to the snow dome), and saying "I thought you said we were going to get good snows this year"..........yada yada yada. He's really been blasting me. I'd like to see him get blasted this year, even if mby doesn't. Link to comment Share on other sites More sharing options...
tnweathernut Posted January 21, 2015 Share Posted January 21, 2015 12z NAM looks even colder through 42 in central and west TN. Should see precip start breaking out shortly after 42 on the NAM when looking at 500. Let's see if more of mid TN can get a paste job on this run. Link to comment Share on other sites More sharing options...
tnweathernut Posted January 21, 2015 Share Posted January 21, 2015 1005mb low just northeast of New Orleans and light precip in southern mid TN at hour 45. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 21, 2015 Share Posted January 21, 2015 Still sn.,not much change otherwise,my concern though still is the lower levels for Mid Tn,saw a slight warming that run,only a degree but not much wiggle room Link to comment Share on other sites More sharing options...
tnweathernut Posted January 21, 2015 Share Posted January 21, 2015 12z NAM still shows potential snowfall in parts of western TN, northern middle TN, and certainly Kentucky, but has backed off amounts shown at 6z just a little. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 21, 2015 Share Posted January 21, 2015 PROBABILISTIC HEAVY SNOW AND ICING DISCUSSIONNWS WEATHER PREDICTION CENTER COLLEGE PARK MD403 AM EST WED JAN 21 2015 VALID 12Z WED JAN 21 2015 - 12Z SAT JAN 24 2015 ...DAY 1... ...GREAT LAKES/MIDDLE ATLANTIC/SOUTHERN NEW ENGLAND... A MODEST TROUGH OVER THE MIDWEST WILL MOVE EASTWARD WITH A REGIONOF UPPER LEVEL DIFFLUENCE DOWNWIND OF THE TROUGH AXIS ALONG THEMID ATLANTIC COAST AND A REGION OF UPPER CONFLUENCE OVER NEWENGLAND. AS THE TROUGH APPROACHES THE MID ATLANTIC COAST ONWEDNESDAY AFTERNOON...A WEAK SURFACE LOW OVER NORTH CAROLINA WILLBEGIN TO DEVELOP AND MOVE EAST OF THE VIRGINIA COAST BY THURSDAYEVENING. THE CONFLUENCE WILL KEEP THE QPF MOSTLY SOUTH OF SOUTHERNNEW ENGLAND EXCEPT FOR THE IMMEDIATE COASTLINE. WHILE LIGHT SNOWWILL CONTINUE TO CROSS THE UPPER OHIO VALLEY ON EARLY WEDNESDAYAND MOVE ACROSS PENNSYLVANIA BY MID WEDNESDAY...AN AREA OFRAIN/SNOW WILL DEVELOP FROM VIRGINIA NORTHEASTWARD ACROSSMARYLAND/DELAWARE AND NEW JERSEY. WHILE MOST ACCUMULATIONS WILLLIKELY RANGE FROM 1 TO 4 INCHES IN THIS AREA...THERE IS ACONSENSUS AMONG THE 00Z OPERATIONAL RUNS THAT A SWATH OF MORESIGNIFICANT QPF MAY DEVELOP FROM EASTERN VIRGINIA/DELMARVA INTOSOUTHERN NEW JERSEY. SOME OF THE QPF MAY BE A MIX OF RAIN/SNOW BUTTHERE IS A LOW PROBABILITY THAT 4 OR MORE INCHES OF SNOW MAY FALLFROM ACROSS SOUTHWEST PENNSYLVANIA AND THE APPALACHIANS FROM SW PAINTO EASTERN WEST VIRGINIA...AS WELL AS NORTHEASTMARYLAND/SOUTHEASTERN PENNSYLVANIA/DELAWARE INTO NEW JERSEY. INGENERAL...THE MODEL BLEND USED TO GENERATE THE FIRST GUESSINCLUDED THE 12Z ECMWF/18Z GFS/18Z GEFS MEAN AND THE BIASCORRECTED SUPER ENSEMBLE. ...DAYS 1 TO 3... ...SOUTHERN ROCKIES/SOUTHWEST/SOUTHERN HIGH PLAINS/TENNESSEEVALLEY/APPALACHIANS/MID ATLANTIC... A POTENTIALLY HIGH IMPACT STORM FIRST AFFECTING THE SOUTHERNROCKIES/SOUTHWEST AND SOUTHERN PLAINS ON DAYS 1 AND 2 BECOMES ASIGNIFICANT SNOW/ICE THREAT FOR THE TENNESSEEVALLEY/APPALACHIANS/MID ATLANTIC BEGINNING ON DAY 3. TWO TROUGHS...ONE OF THE THE DESERT SOUTHWEST AND THE OTHER DIVINGSOUTHWARD FROM THE NORTHERN ROCKIES WILL MERGE ON WEDNESDAY ANDTHURSDAY INTO A SIGNIFICANT UPPER TROUGH OVER THE SOUTHWEST. SNOWIS DEVELOPING THIS MORNING ALONG THE FRONT SLOPES OF THE COLORADOROCKIES AND WILL SPREAD SOUTHWARD ACROSS SOUTHERN COLORADO/MUCH OFCENTRAL/NORTHERN AND EASTERN NEW MEXICO/SOUTHWEST KANSAS/THEPANHANDLES OF OKLAHOMA AND TEXAS/WESTERN OKLAHOMA/WESTERN TEXASAND AN AREA ALONG THE RED RIVER VALLEY BETWEEN OKLAHOMA AND TEXAS.THE HEAVIEST SNOW IS EXPECTED TO DEVELOP ALONG THE FRONT SLOPESOF THE ROCKIES FROM CENTRAL AND SOUTHERN COLORADO ACROSS PARTS OFTHE SAN JUAN AND SANGRE DE CRISTO RANGES...WHERE THERE IS A HIGHPROBABILITY OF AT LEAST 8 TO 12 INCHES OF SNOW. AMOUNTS IN EXCESSOF A FOOT OF SNOW IS EXPECTED IN PORTIONS OF SOUTHERNCOLORADO/NORTHEAST NEW MEXICO AND THE WESTERN PANHANDLES OF TEXASAND OKLAHOMA. AS THE TROUGH MOVES EASTWARD AS A POSITIVELY TILTED TROUGH ONTHURSDAY INTO EARLY FRIDAY...SNOW WILL LINGER ACROSS SOUTHEASTERNNEW MEXICO AND WESTERN TEXAS AND BEGIN TO SPREAD EASTWARD ALONGTHE RED RIVER VALLEY BETWEEN OKLAHOMA AND TEXAS. THERE IS A LOW TOMODERATE PROBABILITY OF SNOWFALL EXCEEDING 4 INCHES ACROSSSOUTHEAST NEW MEXICO AND WESTERN TEXAS. THERE ARE SIGNIFICANTDIFFERENCES IN THE AMOUNT OF SNOW FORECAST FOR THE RED RIVERVALLEY...WITH ONLY LIGHT ACCUMULATIONS PREDICTED BY THE GFS/ECMWFAND ENSEMBLES WHILE THE LATEST 00Z NAM/21Z SREF MEMBERS FORECASTMUCH HIGHER AMOUNTS. AS A RESULT...THERE IS A LOW PROBABILITY OFGREATER THAN 4 INCHES OF SNOW ALONG THE WESTERN RED RIVERVALLEY...ALTHOUGH WPC FORECASTERS TENDED TO IGNORE THE NAM/SREF INFAVOR OF THE ECMWF/GFS SINCE THE QPF AMOUNTS SEEMED TO BE BETTERCORRELATED TO A WEAKER SYSTEM THAN FORECAST BY THE NAM. ON DAY 3/FRIDAY INTO EARLY SATURDAY...THE POSITIVELY TILTED TROUGHMOVES EASTWARD AND THEN BEGINS TO EVOLVE INTO AN INCREASINGLYNEUTRAL AND THEN NEGATIVELY TROUGH MOVING ALONG THE GULF COASTBEFORE STARTING TO HEAD NORTHEASTWARD ALONG THE ATLANTIC COAST.WHILE AN AREA OF CONFLUENCE OVER THE EASTERN US IS ASSOCIATED WITHRISING PRESSURES ALONG THE EASTERN US AHEAD OF THISSYSTEM...ALLOWING COLDER AIR TO PRECEDED THE STORM BEFORE MOVINGUP ALONG THE EAST COAST...THE CONFLUENCE SUBSIDES AND HIGHPRESSURE MOVES OFF THE EAST COAST. HOWEVER...THERE IS ENOUGH COLDAIR THAT A THREAT OF SNOW/SLEET AND FREEZING RAIN REDEVELOPS ALONGTHE NORTHERN FRINGE OF THE PRECIPITATION SHIELD ON FRIDAY INTOEARLY SATURDAY FROM THE TENNESSEE VALLEY INTO THE APPALACHIANS ANDALONG PORTIONS OF THE MID ATLANTIC STATES. BY SATURDAYMORNING...THERE IS A LOW TO MODERATE CHANCE OF GREATER THAN 4INCHES OF SNOW FROM NORTHEAST TENNESSEE/EASTERN KENTUCKY INTO THEMOUNTAINS OF NW NORTH CAROLINA/WESTERN VIRGINIA INTO EASTERN WESTVIRGINIA AND WESTERN MARYLAND. THE HIGHEST TOTALS ARE EXPECTED TOBE IN THE 4 TO 8 INCH RANGE OVER THE ELEVATED TERRAIN OF EASTERNWEST VIRGINIA AND WESTERN VIRGINIA BY SATURDAY MORNING...BUT THISIS ONLY THE START OF THIS STORMS TRACK ALONG THE EAST COAST. THEREIS ALSO A CHANCE THAT A STRIP OF FREEZING RAIN WILL DEVELOP ASWELL FROM EXTREME NORTHEAST GEORGIA UP ALONG THE SPINE OF THEAPPALACHIANS INTO PORTIONS OF THE MIDDLE ATLANTIC STATES...WHERETHERE IS A LOW PROBABILITY OF GREATER THAN .25 INCHES OF ICE FROMTHE MOUNTAINS OF WESTERN NORTH CAROLINA INTO WESTERN VIRGINIA.THE 00Z ECMWF/GFS/00Z GEFS MEAN AND THE 12Z ECMWF ENSEMBLE MEANWERE USED TO BASE THE FIRST GUESS OF THE SNOWFALL/ICE FORECAST. THE PROBABILITY OF 0.25 INCHES OF ICE IS LESS THAN 10 PERCENTACROSS THE CONTIGUOUS US ON DAYS 1 AND 2. KOCIN Link to comment Share on other sites More sharing options...
Jed33 Posted January 21, 2015 Share Posted January 21, 2015 Hmmm thanks for the read Jax. If Paul Kocin is at least talking about the potential in the TN Valley, then I'm interested. There are not many out there that have his knowledge and skill at predicting Eastern US snowstorms. Link to comment Share on other sites More sharing options...
tnweathernut Posted January 21, 2015 Share Posted January 21, 2015 Hmmm thanks for the read Jax. If Paul Kocin is at least talking about the potential in the TN Valley, then I'm interested. There are not many out there that have his knowledge and skill at predicting Eastern US snowstorms. Ditto, I agree. Will be interesting to see what happens. I hope there are GOOD surprises along the way. Link to comment Share on other sites More sharing options...
Stovepipe Posted January 21, 2015 Share Posted January 21, 2015 The GGEM has an unfortunate waffle of the freezing line during peak QPF that greatly lowers snow totals. 1) I'll be interested to see what the higher resolution RGEM shows soon as we are almost in range and 2) just a little change in arrival time could make or break snow if the temps are right on the margin. Regardless, I'd feel pretty good right now if I lived in northwest TN. Link to comment Share on other sites More sharing options...
Stovepipe Posted January 21, 2015 Share Posted January 21, 2015 12z Euro shows the cold air retreating as precip begins Friday and returning in time to make a snowy stripe of 2 to 4 inches extending from Jackson TN to northeast KY. The stripe isn't even wide enough to get Nashville into the mix on that run. Link to comment Share on other sites More sharing options...
Stovepipe Posted January 21, 2015 Share Posted January 21, 2015 It also depicts the clipper as a non-event. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 21, 2015 Share Posted January 21, 2015 Link to comment Share on other sites More sharing options...
tnweathernut Posted January 21, 2015 Share Posted January 21, 2015 Just use this forecast and you will be right 90% of the time.....lol Link to comment Share on other sites More sharing options...
jaxjagman Posted January 21, 2015 Share Posted January 21, 2015 12z Euro shows the cold air retreating as precip begins Friday and returning in time to make a snowy stripe of 2 to 4 inches extending from Jackson TN to northeast KY. The stripe isn't even wide enough to get Nashville into the mix on that run. Started to wonder the GEFS went S this afternoon,the Euro followed Link to comment Share on other sites More sharing options...
jaxjagman Posted January 21, 2015 Share Posted January 21, 2015 Just use this forecast and you will be right 90% of the time.....lol image.jpg lol..we are use to let downs here,least i am. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 21, 2015 Share Posted January 21, 2015 Edit:Thought it was gonna be worse..lol Link to comment Share on other sites More sharing options...
tnweathernut Posted January 21, 2015 Share Posted January 21, 2015 [url="http://www.americanwx.com/bb/index.php?app=core&module=attach§ion=attach&attach_rel_moduleurl] Edit:Thought it was gonna be worse..lol Definitely close enough to watch like a hawk. Would be awesome if you guys could get hit with a 1-3, 2-4 type deal, then crushed at the end of the month/beginning of Feb..... Link to comment Share on other sites More sharing options...
Stovepipe Posted January 21, 2015 Share Posted January 21, 2015 The 12z Euro ensemble mean looks very similar to the operational run for the Friday system in terms of snow. The control is also pretty similar but a bit more generous with snow throughout west TN including Memphis. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 21, 2015 Share Posted January 21, 2015 The 12z Euro ensemble mean looks very similar to the operational run for the Friday system in terms of snow. The control is also pretty similar but a bit more generous with snow throughout west TN including Memphis. 18Z NAM is N through h45 Link to comment Share on other sites More sharing options...
nrgjeff Posted January 21, 2015 Share Posted January 21, 2015 Canadian is a hockey puck to the mouth and the European is a currency devaluation. American models had fewer changes at 12Z, just the usual wobbles run to tun. Last 24 hours situation has perhaps perked up a bit west. First, southeast Tennessee is really going to struggle with warm air. 850 mb temps stay up due to downslope off the Apps. Plus 700 mb warm tongue works in Friday afternoon. Looks like a cold rain from Chattanooga to Knoxville, with flurries maybe snow showers Friday night in Knoxvegas. Perhaps Chatty ends as flurries Friday night. HSV to northwest GA may be all rain too far south. Tri Cities still looks okay for light snow Friday night but will also have to work through the warm nose first. Ditto Upper Plateau. TRI is my pick. Nashville faces weak downslope off the Plateau. Though it is much less of an influence than the Apps, the Plateau can disappoint in Nashville too. Still I think Nashville should end as snow showers at least flurries. Memphis is interesting to watch today. Most guidance keeps 850 mb below freezing for the event, which would bring light snow, but surface temps stay above freezing. If not MEM northwest Tennessee into Middle Kentucky should get sticking snow. Cheers. Link to comment Share on other sites More sharing options...
Stovepipe Posted January 21, 2015 Share Posted January 21, 2015 Canadian is a hockey puck to the mouth and the European is a currency devaluation. American models had fewer changes at 12Z, just the usual wobbles run to tun. Last 24 hours situation has perhaps perked up a bit west. First, southeast Tennessee is really going to struggle with warm air. 850 mb temps stay up due to downslope off the Apps. Plus 700 mb warm tongue works in Friday afternoon. Looks like a cold rain from Chattanooga to Knoxville, with flurries maybe snow showers Friday night in Knoxvegas. Perhaps Chatty ends as flurries Friday night. HSV to northwest GA may be all rain too far south. Tri Cities still looks okay for light snow Friday night but will also have to work through the warm nose first. Ditto Upper Plateau. TRI is my pick. Nashville faces weak downslope off the Plateau. Though it is much less of an influence than the Apps, the Plateau can disappoint in Nashville too. Still I think Nashville should end as snow showers at least flurries. Memphis is interesting to watch today. Most guidance keeps 850 mb below freezing for the event, which would bring light snow, but surface temps stay above freezing. If not MEM northwest Tennessee into Middle Kentucky should get sticking snow. Cheers. As always, thanks for sharing your thoughts Jeff. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 22, 2015 Share Posted January 22, 2015 0Z NAM more over running out west,not sure what this is gonna do Link to comment Share on other sites More sharing options...
jaxjagman Posted January 22, 2015 Share Posted January 22, 2015 slowed down by the looks Link to comment Share on other sites More sharing options...
Stovepipe Posted January 22, 2015 Share Posted January 22, 2015 slowed down by the looks The radar reflectivity with p-type actually looks kind of decent early Saturday morning from middle TN, across the highland rim, to the plateau. But unfortunately the 12k resolution snow accumulation maps only show a dusting from it. Edit: So basically that suggests some periods of decent flakage across a good part of the state late Friday night early Saturday with next to nothing to show for it. Never even changes over in the central and southern valley. But at least the clipper looks wet unlike the Euro. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 22, 2015 Share Posted January 22, 2015 The radar reflectivity with p-type actually looks kind of decent early Saturday morning from middle TN, across the highland rim, to the plateau. But unfortunately the 12k resolution snow accumulation maps only show a dusting from it. Edit: So basically that suggests some periods of decent flakage across a good part of the state late Friday night early Saturday with next to nothing to show for it. Never even changes over in the central and southern valley. But at least the clipper looks wet unlike the Euro. Who knows if the NAM is right,it popped a secondary that stole all the energy by the looks,first time i seen this Edit:who know,i just noticed the 18z did thing same thing on the NAM Link to comment Share on other sites More sharing options...
John1122 Posted January 22, 2015 Author Share Posted January 22, 2015 MRX says a couple of inches Plateau and Mountains with the deformation band, 1 inch or less central/northern valley, dusting southern valley. My forecast is now rain before 9 Friday night, then snow, with light accumulations possible, low 32. I really hope the deformation band gives some vigorous rates and everyone gets at least an inch or two. Especially the Nashville area folks. Link to comment Share on other sites More sharing options...
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