bubba hotep Posted January 15, 2015 Share Posted January 15, 2015 Another analog to consider is '36-37, strong +PDO, weak +AMO, weak +MEI, it had a cold November and warm December. January doesn't look like it is going to be a great match (looking colder in the east than in '37). Feb was pretty much avg with a cold March but it was way dry in Feb/March. I'm not sure any analogs are going to work at this point with off the charts +PDO and record MJO in December. I really hope we can get something out of the cold shot that looks to come towards the end of January b/c climo starts working against us pretty fast in Feb. I mentioned the winter of '36-37 above since the AMO and MEI appear to be somewhat of a decent match to the current situation but Weather5280.com went a step farther with all the strong +PDO Decembers: You can see the write up here. Link to comment Share on other sites More sharing options...
bubba hotep Posted January 15, 2015 Share Posted January 15, 2015 Link to comment Share on other sites More sharing options...
vwgrrc Posted January 15, 2015 Share Posted January 15, 2015 For what. Next Thursday? Link to comment Share on other sites More sharing options...
wxmx Posted January 15, 2015 Share Posted January 15, 2015 Someone looked and liked the 12z Euro Link to comment Share on other sites More sharing options...
Quixotic1 Posted January 15, 2015 Share Posted January 15, 2015 Someone looked and liked the 12z Euro Very impressive. Ironically, just as the deterministic picked it up, the 00z control lost it. Be interesting to see if it's back for the control's 12z run. I love storms barreling in from the north of west. Link to comment Share on other sites More sharing options...
Quixotic1 Posted January 15, 2015 Share Posted January 15, 2015 From FWD: A STRONG COLD FRONT...POSSIBLY OF ARCTIC ORIGIN IS FORECAST BY MEDIUM RANGE MODELS TO MOVE THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY. BOTH THE GFS AND EURO WANT TO DETACH STRONGER SHORTWAVE ENERGY ALOFT ACROSS THE SOUTHERN ROCKIES AND SOUTHWEST U.S...WITH THE NEW 12Z EUROPEAN MODEL STRONGER THAN THE GFS. INCREASING SOUTHWEST FLOW ALOFT SHOULD TAP INTO RICH TROPICAL PACIFIC MOISTURE IN THE MID LEVELS WITH MODIFIED GULF MOISTURE RIDING OVER THE FRONTAL INVERSION WED NIGHT THROUGH THURS NIGHT PERIOD. WE HAVE MAINTAINED ONLY A CHANCE FOR A COLD RAIN DURING THIS PERIOD DUE TO UNCERTAINTIES ON SYSTEM TIMING/STRENGTH AND MOISTURE/TEMP PROFILES THROUGH THE ATMOSPHERE. CONFIDENCE WILL LIKELY REMAIN LOW UNTIL THIS SYSTEM GETS BETTERS SAMPLED IN FUTURE UPPER AIR RUNS. OVERNIGHT THURSDAY AND FRIDAY LOOKS CHILLY. IN ADDITION...THE EURO LIFTS A MUCH STRONGER TROUGH ACROSS THE AREA VERSUS THE GFS WITH A HIGHER THREAT FOR POSSIBLE WINTER PRECIPITATION...LIKELY IN THE FORM OF SNOW. AGAIN...IT IS WAY TOO EARLY TO ACCURATELY ASSESS THIS SYSTEM AND WE WILL CONTINUE TO AWAIT CLEARER DETAILS TO PRESENT THEMSELVES AS WET GET CLOSER TO THE EVENT. UNTIL THEN...ENJOY THE MILD AND MOSTLY SUNNY WEATHER Link to comment Share on other sites More sharing options...
wxmx Posted January 15, 2015 Share Posted January 15, 2015 It all depends where the west coast ridging sets up shop, and how it evolves from that. The op GFS has been showing for most of it's runs a classic W Canada coast to W US coast ridge. That setup would favor Canadian polar air to build south. It also favors a positive tilted trough from Hudson Bay/Great Lakes southwestward to N MX. This setup is usually very progressive, cold and allows for mid/upper level disturbances to travel near/along the base of the trough. Since the source of cold air wouldn't be that cold, as it's after a period of milder temps along S Canada and most of the CONUS, this would probably benefit the very Nern portion of our region to the central plains. Because of the progressive nature of this setup, it would probably evolve into an eastern CONUS trough, with coolish, but not quite frigid conditions for the Sern Plains...a classic +PNA setup. The GFS ensembles mostly support the op GFS, but they have the mean ridge a bit farther north the W Canada coast. GGEM and it's ensembles are somewhat similar to the GFS ensembles. The Euro, OTOH, has this strong ridging even further north the coast in the means, closer to the Canada/AK border. The source of air mass is colder in this setup (arctic air), and longer lasting. The 0z Euro is even further north, fully into Alaska, lowering significantly into negative territory for the EPO. The 12z Euro is midway it's older run and the GFS ensembles, but with stronger ridging. Also, it shows a positive trough, with a storm in it's base, and a more persistent pattern, with the trough not progressing east as fast as the GFS. The Euro ensembles are more in lock with the -EPO setup, and then evolving into a west coast ridge. That last setup (persistent -EPO, evolving into a West Coast/western third ridge, with a positive tilted trough) is usually the coldest setup for the southern portions of our region...the extreme version of this setup is called the McFarland signature (just a few evolve into McFarland's). Usually we get some very interesting events from this setup. It usually needs time to simmer (establish cross polar flow, and then establish a pattern that would shepherd that cold south effectively), and usually there are several bouts of arctic air masses intrusions, each one colder than the prior, before the pattern changes. So, to recapitulate: The GFS has near neutral EPO, with Canadian cold seeping down, and then migrating the trough position east in a +PNA pattern. It's ensembles have a more negative EPO, but not a well established cross polar flow. Also, these ensembles are colder, with a more negative EPO prior to the 12z run. The Euro is more much aggressive with the negative EPO, effectively establishing cross polar flow, with a more stable central CONUS trough, which favors more arctic air intrusions. Also, it features very strong W Coast ridging, so it features a very healthy positive trough that would affect the Sern Plains to Nern MX with wintry precipitation. It's ensembles mostly support the op run, although the ridging is further NW, over AK. The op GGEM is similar to the GFS, while the ensembles are more closely related to the Euro and it's ensembles. Interesting times after day 7. Link to comment Share on other sites More sharing options...
Srain Posted January 16, 2015 Share Posted January 16, 2015 Good evening from Taos Ski Valley. It was a warm 10F here this morning, but 'warmed' to 35F this afternoon at 9500 feet. I had an awesome day of sightseeing and drove the ‘Enchanted Circle’. My 90 mile road trip began in Taos Ski Valley with the first stop being the Rio Grande Gorge Bridge. The skies were perfectly clear offering a fantastic view of Wheeler Peak and Kachina Peak off to the East. Next I drove North on NM 522 to Questa and turned East on NM 38 to Red River. The base of the Red River Ski area is almost into the center of the town of Red River. I continued East on NM 38 to Eagles Nest before heading South on US 64. It was a beautiful day to see Wheeler and Kachina Peaks from the other side of the Sangre de Christo Mountains. I made a stop at the Vietnam War Memorial just outside of Angle Fire. It was a simple, but moving Memorial. Next I ventured to angle Fire. It had been over 30 years since I last visited the area and my, had it changed. I skied Angle Fire first back in the late 70’s when I was a young man and returned in the early 80’s. Needless to say the Resort had expanded and grown since the last visit I made. The drive back to Taos on US 64 was just as I had remembered. This winding…curving two lane road with hairpin turns along the way. It was a great day circling Carson National Forest which Ski Taos, Ski Red River and Ski Angle Fire are in close proximity of. Carson National Forest was established with a merger of Taos National Forest and Jemez National Forest in 1908. Link to comment Share on other sites More sharing options...
bubba hotep Posted January 16, 2015 Share Posted January 16, 2015 Good evening from Taos Ski Valley. It was a warm 10F here this morning, but 'warmed' to 35F this afternoon at 9500 feet. I had an awesome day of sightseeing and drove the ‘Enchanted Circle’. My 90 mile road trip began in Taos Ski Valley with the first stop being the Rio Grande Gorge Bridge. The skies were perfectly clear offering a fantastic view of Wheeler Peak and Kachina Peak off to the East. Next I drove North on NM 522 to Questa and turned East on NM 38 to Red River. The base of the Red River Ski area is almost into the center of the town of Red River. I continued East on NM 38 to Eagles Nest before heading South on US 64. It was a beautiful day to see Wheeler and Kachina Peaks from the other side of the Sangre de Christo Mountains. I made a stop at the Vietnam War Memorial just outside of Angle Fire. It was a simple, but moving Memorial. Next I ventured to angle Fire. It had been over 30 years since I last visited the area and my, had it changed. I skied Angle Fire first back in the late 70’s when I was a young man and returned in the early 80’s. Needless to say the Resort had expanded and grown since the last visit I made. The drive back to Taos on US 64 was just as I had remembered. This winding…curving two lane road with hairpin turns along the way. It was a great day circling Carson National Forest which Ski Taos, Ski Red River and Ski Angle Fire are in close proximity of. Carson National Forest was established with a merger of Taos National Forest and Jemez National Forest in 1908. Nice! I'm a die hard Colorado fan but those are some awesome pics. We are going to do a 3 week tour of the west this summer with the only locked in visit being the Grand Canyon, so we will for sure hit up some New Mexico landmarks. Link to comment Share on other sites More sharing options...
bubba hotep Posted January 16, 2015 Share Posted January 16, 2015 It all depends where the west coast ridging sets up shop, and how it evolves from that. The op GFS has been showing for most of it's runs a classic W Canada coast to W US coast ridge. That setup would favor Canadian polar air to build south. It also favors a positive tilted trough from Hudson Bay/Great Lakes southwestward to N MX. This setup is usually very progressive, cold and allows for mid/upper level disturbances to travel near/along the base of the trough. Since the source of cold air wouldn't be that cold, as it's after a period of milder temps along S Canada and most of the CONUS, this would probably benefit the very Nern portion of our region to the central plains. Because of the progressive nature of this setup, it would probably evolve into an eastern CONUS trough, with coolish, but not quite frigid conditions for the Sern Plains...a classic +PNA setup. The GFS ensembles mostly support the op GFS, but they have the mean ridge a bit farther north the W Canada coast. GGEM and it's ensembles are somewhat similar to the GFS ensembles. The Euro, OTOH, has this strong ridging even further north the coast in the means, closer to the Canada/AK border. The source of air mass is colder in this setup (arctic air), and longer lasting. The 0z Euro is even further north, fully into Alaska, lowering significantly into negative territory for the EPO. The 12z Euro is midway it's older run and the GFS ensembles, but with stronger ridging. Also, it shows a positive trough, with a storm in it's base, and a more persistent pattern, with the trough not progressing east as fast as the GFS. The Euro ensembles are more in lock with the -EPO setup, and then evolving into a west coast ridge. That last setup (persistent -EPO, evolving into a West Coast/western third ridge, with a positive tilted trough) is usually the coldest setup for the southern portions of our region...the extreme version of this setup is called the McFarland signature (just a few evolve into McFarland's). Usually we get some very interesting events from this setup. It usually needs time to simmer (establish cross polar flow, and then establish a pattern that would shepherd that cold south effectively), and usually there are several bouts of arctic air masses intrusions, each one colder than the prior, before the pattern changes. So, to recapitulate: The GFS has near neutral EPO, with Canadian cold seeping down, and then migrating the trough position east in a +PNA pattern. It's ensembles have a more negative EPO, but not a well established cross polar flow. Also, these ensembles are colder, with a more negative EPO prior to the 12z run. The Euro is more much aggressive with the negative EPO, effectively establishing cross polar flow, with a more stable central CONUS trough, which favors more arctic air intrusions. Also, it features very strong W Coast ridging, so it features a very healthy positive trough that would affect the Sern Plains to Nern MX with wintry precipitation. It's ensembles mostly support the op run, although the ridging is further NW, over AK. The op GGEM is similar to the GFS, while the ensembles are more closely related to the Euro and it's ensembles. Interesting times after day 7. The -EPO has been money the last couple of years, so it is hard to bet against it. It is encouraging that both models are similar through about 120 hours, but then the differences really start to show up. This is what I took away from the 12z runs, the tea leaves that we have been reading the last week or so are finally starting to bare fruit and a favorable pattern is emerging. I'll probably try to avoid the models this weekend since we will see all kinds of variations of this system, and of course, we will see the run that totally looses it! Link to comment Share on other sites More sharing options...
vwgrrc Posted January 16, 2015 Share Posted January 16, 2015 The -EPO has been money the last couple of years, so it is hard to bet against it. It is encouraging that both models are similar through about 120 hours, but then the differences really start to show up. This is what I took away from the 12z runs, the tea leaves that we have been reading the last week or so are finally starting to bare fruit and a favorable pattern is emerging. I'll probably try to avoid the models this weekend since we will see all kinds of variations of this system, and of course, we will see the run that totally looses it! All in all, just hope we got colder next Thur than currently forecasted. It certainly looks like another 33-degree-rain event now! Link to comment Share on other sites More sharing options...
wxmx Posted January 16, 2015 Share Posted January 16, 2015 Big changes in the 0z guidance. The Euro appears to have been owned by the GFS big time. No more -EPO...in fact, there's almost no arctic air involved, just Canadian and Pacific polar air...which means that the southern half of our region can forget about wintry precipitation, with the northern half struggling with temps...garden variety cold. The STJ is still pretty active in model world, but the prospects of sustained cold appear to be significantly diminished. Even the GFS is a bit warmer than prior runs. Currently, the Euro and GGEM ensembles appear to have some ridging over AK, but even that has weakened in the 0z run. There appears no other source of arctic air, as the AO looks to stay mostly neutral to positive (very positive in the GFS). Link to comment Share on other sites More sharing options...
DFWWeather Posted January 16, 2015 Share Posted January 16, 2015 Big changes in the 0z guidance. The Euro appears to have been owned by the GFS big time. No more -EPO...in fact, there's almost no arctic air involved, just Canadian and Pacific polar air...which means that the southern half of our region can forget about wintry precipitation, with the northern half struggling with temps...garden variety cold. The STJ is still pretty active in model world, but the prospects of sustained cold appear to be significantly diminished. Even the GFS is a bit warmer than prior runs. Currently, the Euro and GGEM ensembles appear to have some ridging over AK, but even that has weakened in the 0z run. There appears no other source of arctic air, as the AO looks to stay mostly neutral to positive (very positive in the GFS). Not biting off on this solution quite yet. The 51 member ECMWF ensemble suite all favor Arctic cold in the 5 to 10 day spreads unanimously. If anything, run-to-run op ECMWF has been anything but consistent this year. Would expect future op runs to trend back toward the colder solution, whether it will be in time for this storm system next week or not. Likely not as this winter has shown practically no phasing at all between southern stream systems and Arctic cold. Bottom line, cold is coming back by end of the month into early Feb. Link to comment Share on other sites More sharing options...
bubba hotep Posted January 16, 2015 Share Posted January 16, 2015 Big changes in the 0z guidance. The Euro appears to have been owned by the GFS big time. No more -EPO...in fact, there's almost no arctic air involved, just Canadian and Pacific polar air...which means that the southern half of our region can forget about wintry precipitation, with the northern half struggling with temps...garden variety cold. The STJ is still pretty active in model world, but the prospects of sustained cold appear to be significantly diminished. Even the GFS is a bit warmer than prior runs. Currently, the Euro and GGEM ensembles appear to have some ridging over AK, but even that has weakened in the 0z run. There appears no other source of arctic air, as the AO looks to stay mostly neutral to positive (very positive in the GFS). The 00z runs were not encouraging but model thrashing is to be expected at that range. The thing that worries me is the AO and the raging +PDO. I would lean towards neutral AO and -EPO until something starts to strongly signal otherwise. Link to comment Share on other sites More sharing options...
aggiegeog Posted January 16, 2015 Share Posted January 16, 2015 I am liking what I am seeing from the models as far as potential winter weather starting late next week and continuing for a few weeks. I am seeing a SW upper low and a Mississippi River center trough as the general idea for the end of Jan into Feb. That is a cool, moist set-up for Texas. Still hoping for a -AO at some point or we could be looking at more of what we saw to start this month with multiple rounds of cold rain/freezing rain. Hate to waste one of the coldest winters by not getting any accumulating snow; we already did that last year here. Link to comment Share on other sites More sharing options...
Srain Posted January 16, 2015 Share Posted January 16, 2015 The January thaw is underway and should continue into early next week. The pattern does attempt to change later next week, but this colder regime will not be like the last. Temperatures across Eurasia and NW Canada are currently much warmer than the late December/early January period when temperatures were running in the -35 to -45 range in our source Regions. The extended period may offer a return to a much colder pattern and the 500mb pattern looks promising. Next week looks to be just a chilly, dreary period with temperatures warmer by about 7-10 degrees ~vs~ the events of the past 10 days. The Pacific is not cooperating for those looking for a wintry pattern except for the higher elevations of W Texas and New Mexico in the Medium Range. Link to comment Share on other sites More sharing options...
vwgrrc Posted January 17, 2015 Share Posted January 17, 2015 The desirable is always far away, and disappear when we get close Link to comment Share on other sites More sharing options...
Quixotic1 Posted January 18, 2015 Share Posted January 18, 2015 And then.....depression set in.... So far, this has to be one of the most disappointing winters. Not necessarily the results because we have certainly had worse, but as far as expectations versus results. Hype mongers like you-know-who should lose their livelihood over this. 2009 - 10 had no red flags. This one certainly did. The IO, QBO and solar states all should have given pause. Don't get me wrong, we could see something in February but my faith is dwindling even in that small condolence. No matter what happens next, the comparisons to 76-77 and 77-78 look foolish now. Ok. Last rant of the winter. Realism vs optimism and pessimism from here on out. Link to comment Share on other sites More sharing options...
aggiegeog Posted January 18, 2015 Share Posted January 18, 2015 And then.....depression set in.... So far, this has to be one of the most disappointing winters. Not necessarily the results because we have certainly had worse, but as far as expectations versus results. Hype mongers like you-know-who should lose their livelihood over this. 2009 - 10 had no red flags. This one certainly did. The IO, QBO and solar states all should have given pause. Don't get me wrong, we could see something in February but my faith is dwindling even in that small condolence. No matter what happens next, the comparisons to 76-77 and 77-78 look foolish now. Ok. Last rant of the winter. Realism vs optimism and pessimism from here on out. We are lacking in winter storms, but this is going to be one of the coolest months we have seen in agood while. Many years February is the best month for winter storms. Link to comment Share on other sites More sharing options...
bubba hotep Posted January 18, 2015 Share Posted January 18, 2015 I would take this all day any day: We have just been stuck in such a crappy pattern as far as precipitation goes for N. Texas. Everything has been positive tilt and in the process of shearing out as it moves across Texas. You can find a number of things that point towards us staying colder than normal well into Spring but will we get any drought relief? Transient cold with NW flow alfot... Link to comment Share on other sites More sharing options...
bubba hotep Posted January 18, 2015 Share Posted January 18, 2015 We are lacking in winter storms, but this is going to be one of the coolest months we have seen in agood while. Many years February is the best month for winter storms. If you are buying the +PDO as a main driver of the pattern then February is what I would place my bets on. It looks cold and wetter (than January or March) so that could give us our best chances. I arbitrarily picked +1.75 or greater as the cutoff for the December PDO (this is super scientific!) and this is what you get for February: Link to comment Share on other sites More sharing options...
Quixotic1 Posted January 18, 2015 Share Posted January 18, 2015 ...........Nov.....dec.....jan.....Feb.....mar..... 14-15..-5.1.....+3.0...-8.2....???.....???.... 13-14..-3.1.....-4.0....-0.6....-3.0.....-2.5 77-78..+0.6....-0.3....-11.0..-12.0...-0.9 76-77..-6.3.....-2.9....-10.1..+0.7...+2.2 Snowfall in chronological order: 10.4....17.6....2.9....T All numbers for DFW. Granted it was cold in November and so far in January. The chances of it being close to climb for the rest of January is pretty good, so the current departure might not look quite as impressive. December was a torch. WRT wintry precip, last year at least there were opportunities. This year other than some IP and light SN in NOV we're getting nothing. To bubba hoteps point, we're stuck in NW flow. Normally this isn't a bad thing if we can get some type of overrunning or STJ action. If we want to change it we have to develop some type of negative AO or NAO to buckle the jet differently. With all the poor placement of the recently awakened MJO, continued active sun and a cratered QBO, I don't see it changing soon enough to benefit us much this winter. The QBO isn't changing, the sun won't quiet quickly. Our only hope is the MJO. It seems to hit a brick wall with every pulse. Granted its a little bit further east each time, but we're running low on chances. Anywho, I will probably be back on board the next time the euro shows something within 7 days. Link to comment Share on other sites More sharing options...
bubba hotep Posted January 18, 2015 Share Posted January 18, 2015 So, I wouldn't give up totally on next Thursday/Friday... I mean, I probably should but I haven't Link to comment Share on other sites More sharing options...
ams30721us Posted January 18, 2015 Share Posted January 18, 2015 So, I wouldn't give up totally on next Thursday/Friday... I mean, I probably should but I haven't Nope, great point. In fact all 12z Guidance has come in with plenty of QPF and 850's plenty cold enough for snow during the Wednesday night and first half of Thursday. The caveat right now, seems to be surface temps during the period. Interesting developments to say the least. Link to comment Share on other sites More sharing options...
deltadog03 Posted January 19, 2015 Share Posted January 19, 2015 Hot off the presses folks! Sorry that it is a long video, just a ton of stuff to go over. My latest thoughts on the models, and the trends of them. Its a long shot Friday, but there are some positive trends IMHO today. Check out the video for more please, and Thank you!! -Chris https://www.facebook.com/ChriswxmanSimmons Link to comment Share on other sites More sharing options...
bubba hotep Posted January 19, 2015 Share Posted January 19, 2015 Nope, great point. In fact all 12z Guidance has come in with plenty of QPF and 850's plenty cold enough for snow during the Wednesday night and first half of Thursday. The caveat right now, seems to be surface temps during the period. Interesting developments to say the least. I tried to stay away from the models this weekend and focus my free time on some new years resolutions - revisiting some of my grad school stuff and reading at least one AMS journal article each week. I've been working my way through the Synoptic textbook and an AMS journal on modeling errors associated with the Sandy forecast. Anyway, looking at a few things this evening and I am somewhat encouraged but nothing like last Thursday after the 12z Euro run... The trends have certainly been in our favor and we really don't need a whole lot to change before we are easing up on the "wet snow" category. I don't have access to Euro soundings but it looks like we are 0 @ 925, -3 @ 850, -6 @ 700 when the heaviest precipitation moves through but are torching at the surface. I would think we would see some snow with heavier rates but we could really be in business with a cooling trend at the surface. Link to comment Share on other sites More sharing options...
vwgrrc Posted January 19, 2015 Share Posted January 19, 2015 I tried to stay away from the models this weekend and focus my free time on some new years resolutions - revisiting some of my grad school stuff and reading at least one AMS journal article each week. I've been working my way through the Synoptic textbook and an AMS journal on modeling errors associated with the Sandy forecast. Anyway, looking at a few things this evening and I am somewhat encouraged but nothing like last Thursday after the 12z Euro run... The trends have certainly been in our favor and we really don't need a whole lot to change before we are easing up on the "wet snow" category. I don't have access to Euro soundings but it looks like we are 0 @ 925, -3 @ 850, -6 @ 700 when the heaviest precipitation moves through but are torching at the surface. I would think we would see some snow with heavier rates but we could really be in business with a cooling trend at the surface. Is there any cooling sign at surface? Link to comment Share on other sites More sharing options...
aggiegeog Posted January 19, 2015 Share Posted January 19, 2015 I will definitely take the model trend as surface temps are typically modeled warm. I am happy that we are looking at a rain/snow storm and not ice. Link to comment Share on other sites More sharing options...
ams30721us Posted January 19, 2015 Share Posted January 19, 2015 00z Ovnt. models continue the trend of increasing moisture and allowing for the 850/925mb levels to be below freezing. As Bubba stated, if we could cool the lowest levels of the atmosphere, this could be a nice wet snow event across N. TX. Right now, rain snow mix would not be impossible. AM AFD from SHV: AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE SHREVEPORT LA251 AM CST MON JAN 19 2015.DISCUSSION...CONDITIONS TODAY APPEAR SIMILAR TO YESTERDAY WITH SOUTHERLY WINDS5 TO 10 MPH...AND MOSTLY SUNNY SKIES EXCEPT FOR A FEW CIRRUS CLOUDS.AS AFTN TEMPS ROSE TO THE UPPER 60S TO LOWER 70S...EXPECTING SIMILARDAYTIME TEMPS BOTH TODAY AND TUESDAY...WITH A WEAK COLD FRONTWASHING OUT OVER SOUTHERN PLAINS PROVIDING LITTLE IMPACT ON WX. HOWEVER...A STRONGER BACKDOOR FRONT ARRIVING MID WEEK...WILL COMBINE WITHTHE BASE OF A DEEPENING UPPER TROUGH OVER CENTRAL TX...TO BRINGOVERRUNNING RAINS INTO AREA...WITH NE LOW LVL FLOW BENEATH A DEEPENINGSW FLOW ALOFT. ALTHOUGH THE BULK OF HEAVY RAINFALL WILL REMAINJUST SOUTH OF AREA...WHERE BACKDOOR FRONT STALLS OUT.HOWEVER...MODELS NOW TRENDING NORTHWARD WITH SOME OF THEPRECIP...SO HAVE SLIGHTLY INCREASED POPS OVERALL WITH THIS SYSTEM...BEGINNINGWEDNESDAY NIGHT...AND MOVING SOUTH AND EAST OF AREA ON FRIDAY. NORTHERNPORTIONS OF THE AREA COULD SEE A RAIN AND SNOW MIX...ACCORDING TODEEP MOISTURE EXTENDING WELL INTO THE SNOW CRYSTAL GROWTHREGION. HOWEVER...DETAILS IN LOW LVL PROFILE WILL DICTATE THISPOTENTIAL...AND TOO FAR OUT IN FORECAST TO DEVIATE FROMOVERRUNNING RAIN ONLY EVENT./VII/. Link to comment Share on other sites More sharing options...
ams30721us Posted January 19, 2015 Share Posted January 19, 2015 AM AFD FWD: Also noting the fact that while surface temps are pretty warm across most of N. TX during this event...most of the column will be well below freezing. An indication while, not modeled as a complete snow setup....conditions are right on the border to see some areas of snow mixing in across the region. THE MOST RECENT COLLECTION OF MODEL SOUNDING DATA INDICATES THAT AMIX OF RAIN AND SNOW WILL BE A POSSIBILITY FOR THE NORTHWESTERN-MOST COUNTIES /ROUGHLY ALONG AND NORTH OF A BRECKENRIDGE-DECATUR-SHERMAN LINE/. ALL INDICATIONS ARE THAT SURFACETEMPERATURES HERE WILL REMAIN ABOVE FREEZING...BUT SUB-FREEZINGTEMPERATURES ARE BEING ADVERTISED BY ESSENTIALLY ALL MODELS AT 850MB AND ABOVE. WITH SATURATION ALSO BEING ADVERTISED IN THE -10 TO-20 DEG C DENDRITIC GROWTH ZONE...SOME SNOW WILL LIKELY REACH THEGROUND BEFORE MELTING. THAT BEING SAID...AT THIS TIME WE DO NOTBELIEVE THAT ANY SIGNIFICANT ACCUMULATIONS WILL OCCUR. Link to comment Share on other sites More sharing options...
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