eyewall Posted January 9, 2011 Share Posted January 9, 2011 RAH holding back on warning upgrades: .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... -- Changed Discussion --AS OF 1035 AM... WINTER STORM WATCH REMAINS IN EFFECT FOR MONDAY MORNING THROUGH TUESDAY AFTERNOON. VERY PRELIMINARY THOUGHTS AS OF 1015 THIS MORNING... LIQUID AMOUNTS WILL DRIVE THE IMPACT OF THE FORECAST. GREATEST CHANCE FOR WARNING AMOUNT SNOW IN OUR SOUTHWEST. INCLINED TO HAVE ACCUMULATING SNOW INTO MONDAY EVENING HOURS IN THE SOUTH AND TO EARLY MORNING TUESDAY IN THE NORTH...BUT NO ADJUSTMENTS AT THIS TIME. IF LIQUID AMOUNTS FOR THE EVENT STAY BELOW ONE QUARTER INCH (EXCEPTION SOUTHWEST) THROUGH EARLY MONDAY NIGHT... WARNING FOR SNOW NOT LIKELY. PRECIPITATION AMOUNTS AFTER MIDNIGHT MONDAY NIGHT AND SOUNDINGS INDICATE A LITTLE ACCUMULATING SLEET MANY AREAS FOR A TIME THEN TRANSITIONING TO FREEZING RAIN. LIQUID PRECIPITATION AMOUNTS AT THIS TIME DO NOT INDICATE A WARNING FOR ICE... BUT AT LEAST A TENTH INCH ICE EXPECTED MOST LOCATIONS. STAYING ON THE CONSERVATIVE SIDE OF PRECIPITATION ESTIMATES AND WILL FULLY EVALUATE MORNING MODELS OVER THE NEXT FOUR HOURS. NOT TENDING TOWARD ISSUING A THIRD PERIOD ADVISORY ON THIS SHIFT... SO WATCH TO CONTINUE WITH A EYE ON THE SOUTHWEST... WHERE UPGRADE TO WARNING POSSIBLE THIS SHIFT IF ANALYSIS WARRANTS. Link to comment Share on other sites More sharing options...
burgertime Posted January 9, 2011 Share Posted January 9, 2011 8-10? Sorry for the weenie post but WOW! Link to comment Share on other sites More sharing options...
david30 Posted January 9, 2011 Share Posted January 9, 2011 Couldn't be happier with the latest RUC at 5h, the 700 moisture and UVV. It arrives in western SC and lower NC around 3 AM, perfect timing, by 6 am we should have a covered ground. The rates show good building in northern GA as the axis of deformation gets stretched and it looks like beyond this 18 hour frame that there will be a wall of moisture from Charleston to Memphis, so that tilting is looking like the NAM showed, classic comma head. I know at some point we'll switch over to sleet then ZR from south to north as the event wears on but the area where the snow may max out will probably be in much of the state of TENN, esp. the southern half and eastern third and stretching across the Carolina's border region, either side, and including northern GA, as for absolute final snow tallies and good lift, thats where I'd draw the map for totals. Great storm for everybody though in the Southeast with something for everyone, and the earlier start time will allow the snow to stretch east into the eastern piedmont esp. southeast piedmont. I haven't seen profiles yet but with southeast 850 and decent easterly surface into western SC I see a big snow local max there or around AVL to Marion. So has your thinking changed frm the maps drawn yesterday with NW MS being solidly in the 3-6 based on being north of the 5h or do you think based on the last run more warming gets involved. The last thing i want to go through is an ice storm. Link to comment Share on other sites More sharing options...
phil882 Posted January 9, 2011 Share Posted January 9, 2011 Couldn't be happier with the latest RUC at 5h, the 700 moisture and UVV. It arrives in western SC and lower NC around 3 AM, perfect timing, by 6 am we should have a covered ground. The rates show good building in northern GA as the axis of deformation gets stretched and it looks like beyond this 18 hour frame that there will be a wall of moisture from Charleston to Memphis, so that tilting is looking like the NAM showed, classic comma head. I know at some point we'll switch over to sleet then ZR from south to north as the event wears on but the area where the snow may max out will probably be in much of the state of TENN, esp. the southern half and eastern third and stretching across the Carolina's border region, either side, and including northern GA, as for absolute final snow tallies and good lift, thats where I'd draw the map for totals. Great storm for everybody though in the Southeast with something for everyone, and the earlier start time will allow the snow to stretch east into the eastern piedmont esp. southeast piedmont. I haven't seen profiles yet but with southeast 850 and decent easterly surface into western SC I see a big snow local max there or around AVL to Marion. I like how you talk I'm in general agreement with your thoughts, although I'd go just a touch further south and west with the highest amounts. I'm working on an updated map now and I hope to have that out within the hour. Link to comment Share on other sites More sharing options...
Buddy Posted January 9, 2011 Share Posted January 9, 2011 A bit of fun eye candy: Don't see that sort of map often at all! Link to comment Share on other sites More sharing options...
audioguy3107 Posted January 9, 2011 Share Posted January 9, 2011 Seeing returns as far east on the Birmingham GRLevel3 radar Nice radar pic to be sure....as long as that band holds together, we may be in the game a little earlier than midnight. I still can't believe that we're pretty much smack dab in the sweet spot for this storm, it's unreal....also, the low sure looks healthier on that water vapor loop!!! Link to comment Share on other sites More sharing options...
Cyrys Posted January 9, 2011 Share Posted January 9, 2011 For anybody that may know the Nashville airport well. I am supposed to be flying in early afternoon on Tues. How does snow affect that airport? Also I am then planning on driving towards Knoxville that afternoon. How does TN do at keeping I40 clear of snow and should I expect pretty slow going? Link to comment Share on other sites More sharing options...
eyespygawx Posted January 9, 2011 Share Posted January 9, 2011 For anybody that may know the Nashville airport well. I am supposed to be flying in early afternoon on Tues. How does snow affect that airport? Also I am then planning on driving towards Knoxville that afternoon. How does TN do at keeping I40 clear of snow and should I expect pretty slow going? http://www.flightsta...airportCode=BNA http://www.tdot.stat...s/tdotsmartway/ Link to comment Share on other sites More sharing options...
FoothillsNC Posted January 9, 2011 Share Posted January 9, 2011 Nice radar pic to be sure....as long as that band holds together, we may be in the game a little earlier than midnight. I still can't believe that we're pretty much smack dab in the sweet spot for this storm, it's unreal....also, the low sure looks healthier on that water vapor loop!!! that radar matches up with the initial overrunning band on RUC latest. Its pretty interesting to see the RUC diminish the Gulf convection with time and absorb it, bringing the moisture back into a comma head from northern/central Miss to the Florida panhandle on the last frames, so its essentially a WAA snow sweeping southwest to north east and stretching over time, again much like the NAM has, but I haven't studied the 850's closer on it yet due to time. I'm about to eat then will update the blog and put a finals map on the call thread. http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/ruc/hr4/index_700_l_loop.shtml Link to comment Share on other sites More sharing options...
NCWeSU Posted January 9, 2011 Share Posted January 9, 2011 The only thing thats a bit concerning is the MCV that has developed in the GOM. Looks to already be robbing some moisture per what I see on water vapor. I would be more concerned if it weren't for the reflectivity plots I saw on the 12z nam. Unbelievably, it seems that the nam has actually identified this feature and wants to pick it up and draw it back into the the moisture flow. No wonder the totals went way up this run! Now mesoscale feature are very hard to predict, but if this occurs like the nam is depicting... LOOKOUT! Current Radar... very discernible circulation. It's interesting to see the bowing segment straighten out and it appears that the N to S oriented line of convection is hanging back with the main boundary. In this case it may be possible that it would begin to increase moisture amounts from the Gulf as the LLJ strengthens out ahead of the convection. But it will be very interesting to follow that MCV feature, which is something I doubt the GFS has a good handle on. Link to comment Share on other sites More sharing options...
codgator Posted January 9, 2011 Share Posted January 9, 2011 For anybody that may know the Nashville airport well. I am supposed to be flying in early afternoon on Tues. How does snow affect that airport? Also I am then planning on driving towards Knoxville that afternoon. How does TN do at keeping I40 clear of snow and should I expect pretty slow going? Traveling east towards K-town will be difficult on TUESDAY. The area around COOKEVILLE and CROSSVILLE is high country and if we get the snow forecasted it could be closed. Link to comment Share on other sites More sharing options...
UNCCmetgrad Posted January 9, 2011 Share Posted January 9, 2011 BUFKIT profiles for 12Z NAM at CLT show all of the heavier precipitation as snow. No part of the profile goes above freezing until about 8pm Monday night. This is well after we have lost saturation in the snow growth layer. Link to comment Share on other sites More sharing options...
Lookout Posted January 9, 2011 Share Posted January 9, 2011 My soil temp has only cooled a few degrees over night to 39.6. I'll be interested in what the early sticking rates will be. Still not used to it coming into cold air for a change. T Last night's cold temps really dropped the ground temps. I was a bit surprised at how cold it was this morning here, the low was 14.9. This is several degrees cooler than I thought it would be. Currently many areas ground temps are in the low to mid 30s. This is some 15 to 20 degrees colder than with the last system. I expect them to warm a little over the eastern sections but clouds should keep them in check over the western half. Although ground temps won't be freezing per se, it's much improved over the last system and should really help out accumulations. Link to comment Share on other sites More sharing options...
strongwxnc Posted January 9, 2011 Share Posted January 9, 2011 Can u post the gsp overlay? On bb here. Delete after please. Link to comment Share on other sites More sharing options...
burgertime Posted January 9, 2011 Share Posted January 9, 2011 BUFKIT profiles for 12Z NAM at CLT show all of the heavier precipitation as snow. No part of the profile goes above freezing until about 8pm Monday night. This is well after we have lost saturation in the snow growth layer. Amazing how perfect this is all coming together, though somewhere in the back of my head I'm waiting for the other shoe to drop...which keeping my fingers crossed is not in the form of moisture robbing convection. Link to comment Share on other sites More sharing options...
FoothillsNC Posted January 9, 2011 Share Posted January 9, 2011 Amazing how perfect this is all coming together, though somewhere in the back of my head I'm waiting for the other shoe to drop...which keeping my fingers crossed is not in the form of moisture robbing convection. always nervous here. But I'm not worried on our temps. The RUC has our temps in the damming region dropping even more, probably good rates and a little upslope cooling going on right at the time we're getting into the good moisture, speaking of CLT to GSP and AVL region...your triangle of doom. I imagine the ratios would be pretty good here at -6 or so. Link to comment Share on other sites More sharing options...
eyewall Posted January 9, 2011 Share Posted January 9, 2011 34.5 F soil temp here in the Sandhills as per the climate office ECONet. Trust me they are not a major issue in this event. Link to comment Share on other sites More sharing options...
weathertree4u Posted January 9, 2011 Share Posted January 9, 2011 I work at an great nationally known Educational Instituition off I-40 and across from the airport; I have seen BNA open during tornado warnings; there have only been a hand full of times maybe three over 7 years that I have seen a ground stop at the air port; TDOT is spraying brim and there is alot of rock salt; it has been several years, I believe since the January storm of 1988 that Nashville has had over 8;" I believe it has been that long since I have seen TDOT actually using plows, which will be necessary this time around; I would obviously check with your carrier Tuesday but this is a situation that Nashville and the Southeast in general does not deal with often! http://www.flightsta...airportCode=BNA http://www.tdot.stat...s/tdotsmartway/ Link to comment Share on other sites More sharing options...
burgertime Posted January 9, 2011 Share Posted January 9, 2011 always nervous here. But I'm not worried on our temps. The RUC has our temps in the damming region dropping even more, probably good rates and a little upslope cooling going on right at the time we're getting into the good moisture, speaking of CLT to GSP and AVL region...your triangle of doom. I imagine the ratios would be pretty good here at -6 or so. Yea if the NAM is even somewhat close I can see someone right around us really hitting big. If we can get 8 inches here that will be huge and will practically gridlock the city! Which according to my GF's Mom they have plenty of shovels and window scrapers since Wal-Mart is all out. Link to comment Share on other sites More sharing options...
phil882 Posted January 9, 2011 Share Posted January 9, 2011 GSP is going to have a period of very heavy snowfall early tomorrow morning if this verifies. Link to comment Share on other sites More sharing options...
GaWx Posted January 9, 2011 Share Posted January 9, 2011 Per the 15Z RUC init., the 1004 sfc low is centered at 27N, 95W: 1) How accurate are RUC initializations? 2) If accurate, this seems to be a fair bit further south than what the model consensus has been suggesting..say 75-100 miles. Do others agree? If so, would this mean that the low will likely track further south than the model consensus? Link to comment Share on other sites More sharing options...
Lookout Posted January 9, 2011 Share Posted January 9, 2011 12z canadian has increased amounts over al/ga/sc. I'm happy to see it trend toward the gfs/nam finally Link to comment Share on other sites More sharing options...
BullCityWx Posted January 9, 2011 Share Posted January 9, 2011 Canadian continues to be insistent that whatever falls here is 100% snow. Link to comment Share on other sites More sharing options...
BullCityWx Posted January 9, 2011 Share Posted January 9, 2011 Also of note on the 12z NAM, there is ONE single layer above freezing at hour 42 so theoretically, if the heavier precip rates continue until 42, you could see us holding onto a colder profile. Link to comment Share on other sites More sharing options...
UNCCmetgrad Posted January 9, 2011 Share Posted January 9, 2011 [quote name=burgertime' timestamp='1294590203' = Amazing how perfect this is all coming together, though somewhere in the back of my head I'm waiting for the other shoe to drop...which keeping my fingers crossed is not in the form of moisture robbing convection. There is an excellent powerpoint presentation titled The Effects of Upstream Convection on Downstream Precipitation by Kelly Mahoney and Gary Lackmann. It explains how convection in different orientations can either increase or decrease downstream precipitation. It is a long power point but is you kind of skim over the main points it can help you know what to look for. Here is the link below. Effect of Upstream Convection on Downstream QPF - Slide 1 Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 9, 2011 Share Posted January 9, 2011 Here's what I don't understand, from FFC, new update FXUS62 KFFC 091633AFDFFCAREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PEACHTREE CITY GA 1133 AM EST SUN JAN 9 2011 .UPDATE... PRIMARY CHANGE TO THE FORECAST HAS BEEN THE TOTAL SNOW AND ICE ACCUMULATIONS AMOUNTS EXPECTED FOR SUNDAY NIGHT THROUGH MONDAY. THE LATEST NAM AND GFS MODEL RUNS SUPPORT TWEAKING THE SNOW AMOUNTS DOWN A BIT AND RAISING THE ICE SOME. FOR EXAMPLE THE TOTAL SNOWFALL AMOUNTS EXPECTED IN THE ATLANTA AND ATHENS METRO AREAS ARE EXPECTED TO BE IN THE 2 TO 4 INCH RANGE NOW. WHEN THE SNOW AND SLEET CHANGES OVER TO FREEZING RAIN ON MONDAY THEN EXPECT UP TO ONE QUARTER INCH OF ICE DURING THE DAY. NO OTHER CHANGES NEEDED AT THIS TIME. Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 9, 2011 Share Posted January 9, 2011 The latest RUC run continues w/ a big snowfall for the southern 2/3 of TN. Impressive. Link to comment Share on other sites More sharing options...
wolfpackmet Posted January 9, 2011 Share Posted January 9, 2011 Can u post the gsp overlay? On bb here. Delete after please. Again look at the comparisons of the 1988 storm. Link to comment Share on other sites More sharing options...
ams30721us Posted January 9, 2011 Share Posted January 9, 2011 Tennessee Valley Residents--A Must Read from WAFF 48: Heavy Snow, Thundersnow possible overnight tonight If there is one thing you remember from this post please let this be it. (Shoveling heavy snow can lead to a heart attack please use caution and don't overexert yourself with this winter storm. Always keep safety in mind) We continue to track a developing winter storm. It is possible we could still see a few changes with the exact track and the location of the heaviest band of snow. With previous winter storms in the Tennessee Valley, at this stage in the game, we begin to downplay the event and talk about why it won't snow, that is not the case with this winter storm. Morning data on Pinpoint Predictor is now indicating the possibility of convective snowfall. This is also known as "Thundersnow". Convective snowfall occurs with very dynamic snow storms when the updraft of the snow is more diagonal than vertical. This is mainly due to the fact that the atmosphere becomes thinner in the winter time. If we get this convective snowfall you will see very heavy snowfall rates and there will be lightning and thunder along with snowflakes the size of silver dollars. The morning data in the WAFF 48 Storm Tracking center is now producing a 12-16 inch band of heavy snow in a line from Russellville to Athens to Fayetteville, TN. It looks like it will be about 20 miles either side of that line. When it's all said and done it's possible the exact track of this heavy snow band will end up in another area, the fact that the guidance is putting down these numbers is rather alarming. Confidence is growing that some communities in our viewing area could recieve a 12 inch plus snowfall. IF this becomes the case, in addition to road problems, these areas might also encounter power outages, sinking boat docks, and flat roofs that fail. Flat roofs are the most likely to fail during a 14-18 inch wet snowfall. They fail because the load on the roof is too much. It all depends on how well your roof is constructed. The most vulnerable roofs are those of old businesses with poor drainage. Boat docks begin to sink due to the snow load on the roof as well. If you have a power outage it is best to turn off all power, including the heater, and leave one light on so that you know when the power comes back on. By doing this you will decrease the power load when they try to turn the power back on. Link to comment Share on other sites More sharing options...
Lookout Posted January 9, 2011 Share Posted January 9, 2011 Also of note on the 12z NAM, there is ONE single layer above freezing at hour 42 so theoretically, if the heavier precip rates continue until 42, you could see us holding onto a colder profile. I don't expect a changeover here until around noon tomorrow...in the form of sleet most likely as the boundary layer is ridiculously cold...950mb temps around -6c. By that time, most of the heavy stuff is moving out anyway. The same holds true for much of north georgia. However, atlanta looks like it could pick up more sleet than some. Gfs/nam have the changeover there around 12z tomorrow. But it depends on the intensity of the precip. Regardless, atlanta still recieves a good 4 or 5 inches. The problem is the models always have a hard time handling mid level temps in situations like this. Sometimes the warm nose is stronger and faster than predicted which does worry me somewhat. However, heavy precip and strong dynamics can overcome the waa. For areas like atlanta to south of athens, it will be a battle between these forces. Then it spreads north and honestly we won't know for sure when until it happens. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.