andyhb Posted June 10, 2016 Author Share Posted June 10, 2016 That southern stream wave ejecting this upcoming Tuesday bears watching for the southern Plains and perhaps one last kick at the can for the chasers there. The last three runs of the Euro have shown a setup that looks conducive to tornadic supercells in KS and N OK with a moderate LLJ and a respectable, sub-1000 mb surface low along with 40-50 kt 500 mb flow (the latest run also increased the instability). I am really a fan of these kinds of lower amplitude waves that tend to not force major height rises to the east and create conditions favorable for VBV profiles. The GFS is faster and less favorable, although it appears to be a progressive outlier among the full suite and even its ensemble mean to some degree. Link to comment Share on other sites More sharing options...
brettjrob Posted June 10, 2016 Share Posted June 10, 2016 That southern stream wave ejecting this upcoming Tuesday bears watching for the southern Plains and perhaps one last kick at the can for the chasers there. The last three runs of the Euro have shown a setup that looks conducive to tornadic supercells in KS and N OK with a moderate LLJ and a respectable, sub-1000 mb surface low along with 40-50 kt 500 mb flow (the latest run also increased the instability). I am really a fan of these kinds of lower amplitude waves that tend to not force major height rises to the east and create conditions favorable for VBV profiles. The GFS is faster and less favorable, although it appears to be a progressive outlier among the full suite and even its ensemble mean to some degree. Last night's Euro looked awfully impressive for KS on Tuesday. Nice surprise that's popped up over the last couple days after it had become easy to assume we were done S of I-80 for the year. Given how well the late May setups performed aided by excellent ET/near surface moisture on the High Plains, I'm already excited about the possibilities for this one, even if some details are less than optimal. Link to comment Share on other sites More sharing options...
jojo762 Posted June 10, 2016 Share Posted June 10, 2016 That southern stream wave ejecting this upcoming Tuesday bears watching for the southern Plains and perhaps one last kick at the can for the chasers there. The last three runs of the Euro have shown a setup that looks conducive to tornadic supercells in KS and N OK with a moderate LLJ and a respectable, sub-1000 mb surface low along with 40-50 kt 500 mb flow (the latest run also increased the instability). I am really a fan of these kinds of lower amplitude waves that tend to not force major height rises to the east and create conditions favorable for VBV profiles. The GFS is faster and less favorable, although it appears to be a progressive outlier among the full suite and even its ensemble mean to some degree. 06Z GFS looks quite a bit better... And more comparable to the Euro, it also is a bit stronger with the S/W with winds at H5 at 50-60kt. VBV is more of an issue further north in Nebraska on the GFS than it is in KS/OK, but with southward extent the cap also gets stronger... Forecast soundings at hr 114 (00Z/ June 15) are very impressive along much of the dryline, with extreme instability, strong 0-6KM SHR of 40-55kt, and impressive 0-3KM SHR of ~30kt/0-3KM SRH of 200-300m2/s2....Euro has VBV, but it's only above 500mb, so maybe it is not as much of an issue...hopefully. Will be interesting to watch this evolve. Link to comment Share on other sites More sharing options...
brettjrob Posted June 12, 2016 Share Posted June 12, 2016 lol and right on cue, our last hope for the season S of I-80 has taken a dive since I last posted. Wave mistimed for good Plains action, and also flattening out more on recent guidance. Tomorrow is pretty marginal, and this morning's CAMs are not optimistic at all, but I'm still considering giving it a shot along the CO/KS border (if not farther W... sigh). Otherwise, my first chaseless June will be quite possible. Tuesday is similarly lukewarm for IA/MO. On the plus side, at least the medium range progs have stopped giving us false hope? That's about the best that can be said for the past 2 weeks. Link to comment Share on other sites More sharing options...
Chicago Storm Posted June 12, 2016 Share Posted June 12, 2016 lol and right on cue, our last hope for the season S of I-80 has taken a dive since I last posted. Wave mistimed for good Plains action, and also flattening out more on recent guidance. Tomorrow is pretty marginal, and this morning's CAMs are not optimistic at all, but I'm still considering giving it a shot along the CO/KS border (if not farther W... sigh). Otherwise, my first chaseless June will be quite possible. Tuesday is similarly lukewarm for IA/MO. On the plus side, at least the medium range progs have stopped giving us false hope? That's about the best that can be said for the past 2 weeks. It's not good for anyone who missed the good days during that active week in late-May, as that's the only time this season really produced. Looks like the traditional chase season will end as it started. We'll see if there's any surprise events between now and the fall season. Link to comment Share on other sites More sharing options...
brettjrob Posted June 12, 2016 Share Posted June 12, 2016 It's not good for anyone who missed the good days during that active week in late-May, as that's the only time this season really produced. Looks like the traditional chase season will end as it started. We'll see if there's any surprise events between now and the fall season. No doubt. Once again, as with every year after 2010 so far, a significantly flawed Plains chase season with a few nice bright spots. The good, well-rounded year with a few obvious big days and several more localized gems still eludes us. I will say, thanks to late May, that it was at least a decent chase season (for everyone who made it out that week). That's more than can be said for the overall severe weather season across the country. Link to comment Share on other sites More sharing options...
raindancewx Posted June 26, 2016 Share Posted June 26, 2016 Weathertrends 360 has the core of summer hot/dry for most of the USA. Link to comment Share on other sites More sharing options...
nrgjeff Posted July 5, 2016 Share Posted July 5, 2016 Today should mark the beginning of a 7-10 day stretch of surprisingly good storm chasing so late in the season. Thank the Nino to Nina transition, reaching neutral by late spring. Jet stream is active from the Pac NW across the US/Canada border. SPC already has the box out for western Minnesota today. Distinct boundary offers a focal point for severe, perhaps tornadoes on a dominant cell. Wednesday looks like a good upslope day, from the boundary in northwest Kansas north into the upslope flow. Thursday should be active on the warm front in Iowa, but maybe sloppy. Friday could be the day-before-the-day in MT/ND. Saturday should be active with a defined system approaching North Dakota. LLJ responds to upper jet and moisture returns quite well. I would use Thursday to reposition for Friday, after the Wednesday target. One could argue Friday is the repo day if going from Iowa Thursday to ND Saturday. If I were really chasing I would try upslope Wednesday, repo Thursday, and be in MT/ND Friday. Don't forget the passport Fri/Sat. Sun/Mon the Saturday system lumbers northeast into Canada probably becoming meridional. Later next week another system is possible across the far northern US and/or on the Canadian border. Link to comment Share on other sites More sharing options...
Thunder98 Posted July 6, 2016 Share Posted July 6, 2016 This is my 1st post here on Americanwx forums. Very boring bland weather forecast for Santa Maria, California Link to comment Share on other sites More sharing options...
Mercurial Posted July 6, 2016 Share Posted July 6, 2016 This is my 1st post here on Americanwx forums. Very boring bland weather forecast for Santa Maria, California smwxforcast5.PNG lol is the weather ever not bland down there? My father lives in Nipomo. Link to comment Share on other sites More sharing options...
mayjawintastawm Posted July 6, 2016 Share Posted July 6, 2016 This is my 1st post here on Americanwx forums. Very boring bland weather forecast for Santa Maria, California Welcome! I would like some fog, please. Getting drier and hotter each day. Any thoughts on the start of the SW monsoon? Last year it was a bit of a "nonsoon". Us in the big squarish states could use some more moisture, soon. Link to comment Share on other sites More sharing options...
Thunder98 Posted July 7, 2016 Share Posted July 7, 2016 Welcome! I would like some fog, please. Getting drier and hotter each day. Any thoughts on the start of the SW monsoon? Last year it was a bit of a "nonsoon". Us in the big squarish states could use some more moisture, soon. Looks very quiet! No monsoonal moisture coming back to the Central Coast yet. Link to comment Share on other sites More sharing options...
nrgjeff Posted July 7, 2016 Share Posted July 7, 2016 Welcome to the Forum and Central/West. This is my 1st post here on Americanwx forums. Very boring bland weather forecast for Santa Maria, California Actually I find temperature forecasting quite interesting during the summer in California. One has to look at the marine layer from the coast into the valleys and the sea breeze later in the day. I find Southern California more forgiving. Some days a marine layer or sea-breeze forecast error can negate the other, saving a daily temperature forecast but the hourly may be a mess for a few hours. Northern California coastal valleys can be particularly unforgiving if one blows the marine layer and/or wind direction. Monsoon pattern also offers good forecast challenges. While temperatures do not make for good drama on a forecast forum, it is still interesting to follow. Otherwise, live vicariously in the Plains for some real weather action. Again welcome to the board and region. Link to comment Share on other sites More sharing options...
Thunder98 Posted July 7, 2016 Share Posted July 7, 2016 Welcome! I would like some fog, please. Getting drier and hotter each day. Any thoughts on the start of the SW monsoon? Last year it was a bit of a "nonsoon". Us in the big squarish states could use some more moisture, soon. Welcome to the Forum and Central/West. Actually I find temperature forecasting quite interesting during the summer in California. One has to look at the marine layer from the coast into the valleys and the sea breeze later in the day. I find Southern California more forgiving. Some days a marine layer or sea-breeze forecast error can negate the other, saving a daily temperature forecast but the hourly may be a mess for a few hours. Northern California coastal valleys can be particularly unforgiving if one blows the marine layer and/or wind direction. Monsoon pattern also offers good forecast challenges. While temperatures do not make for good drama on a forecast forum, it is still interesting to follow. Otherwise, live vicariously in the Plains for some real weather action. Again welcome to the board and region. Thank you! The temperature gradient in late spring, summer and through early autumn is quite interesting though. Link to comment Share on other sites More sharing options...
raindancewx Posted July 11, 2016 Share Posted July 11, 2016 The AMO (ESRL/Kaplan) came in at 0.423 for June 2016 - highest June value since 2010. Likely high enough to all but assure it remains positive in the cold season. Not many winters with a PDO+, AMO+, cold Neutral to strong La Nina. Link to comment Share on other sites More sharing options...
nrgjeff Posted August 24, 2016 Share Posted August 24, 2016 If the current weather pattern holds, troughs Central and Southeast ridge, the Midwest fall/encore severe season could be at least somewhat interesting. PDO and ENSO analogs favor at least semi-persistence. Weeklies keep ridging East or Southeast with occasional troughs Central. Naturally Rockies troughs would be ideal for the Plains but most seem to be forming Central. Corn Belt can and occasionally does deliver in fall. I prefer September with the longer days but the above PDO/ENSO analogs have some trough west ridge east in October. My other reason for a September focus, is something other than the heat dragging on locally here in the Tennessee Valley. Living vicariously in the Midwest... Link to comment Share on other sites More sharing options...
raindancewx Posted August 27, 2016 Share Posted August 27, 2016 I was running some figures for the SW, and it seems like in most locations, September is always colder than August in terms of mean highs. That favors September being either near average or cold out here. From 1931-2015, every September in Albuquerque was 1F to 12F colder than August. "Cold" Augusts in La Nina and Neutral years seem to drop off by ~1-8F over the past 85 years. If you blend it all together, the best bet would be a drop of 5F, with September ending up ~1.5F below normal, after August ends up ~2.5 to ~3.5 below normal. The years I'm looking at are 1933, 1935, 1961, 1967, 1971, 1974, 1988, 1989, 1990, 1999 for August in the SW. My somewhat rigorous odds imply ~5% chance of a warm September in the SW (>=+2F v. mean highs) and maybe a 55% chance of near normal (+/-2F) and a ~40% chance of cooler than normal (-2F or less v. mean highs). Link to comment Share on other sites More sharing options...
andyhb Posted August 30, 2016 Author Share Posted August 30, 2016 Seems to be a suggestion of severe potential increasing across the central Plains towards the beginning of next week. Broad cyclonic flow looks to become anchored across the western half of the country at 500 mb with periodic shortwaves passing through the flow leading to amplification of the LLJ. Should be sufficient instability for severe wx and perhaps supercells given the lack of linear forcing. Link to comment Share on other sites More sharing options...
raindancewx Posted September 19, 2016 Share Posted September 19, 2016 I have done a bunch of research for this winter and I generally have the following observations: - Cold shots tend to migrate from west to east to west to east in PDO neutral years. This favors Midwest cold. - NYC, Philly, DC, Richmond - they've all had three winters in a row of above average snowfall. It's hard to get four historically (should occur 2-3 times a century statistically, 0.40^4). - Places like Flagstaff and others west of the Continental Divide have had two to four bad years in a row for snow. Unlikely to continue. - Hasn't been cold in the East in December in several years, hasn't been warm in December in the West for several years. All in all, I like the Central third of the US, particularly north of Chicago and Cheyenne for cold/lots of snow this winter. Link to comment Share on other sites More sharing options...
bjc0303 Posted February 10, 2017 Share Posted February 10, 2017 Seems like some increased severe potential could exist late next weekend into early next week. Both euro and GFS ensemble systems suggest some degree of troughing, with the euro being particularly strong/paced for a plains severe threat. Will certainly be worth monitoring as we go forward. Strong pacific jet extending towards western US coast should allow for western US troughing to begin to take place. Key feature to watch will inevitably be east coast troughing for moisture scouring. Current EPS solution suggests slow moving system allowing for ~72 hours of moisture return. Link to comment Share on other sites More sharing options...
raindancewx Posted February 15, 2017 Share Posted February 15, 2017 JAMSTEC has increased it's forecast strength - and imminence of the coming El Nino. Says it is here in April. Last year, its forecast for La Nina peak strength did well - had it getting to -0.7C around this time last year. Link to comment Share on other sites More sharing options...
bjc0303 Posted February 15, 2017 Share Posted February 15, 2017 That time of year where interesting looking baroclinic waves/tracks and strong dynamics have absolutely no moisture to work with due to frontal intrusions into the GOMEX. This upcoming system will bring plentiful rain into the southern plains (needed - see drought monitor). The next system of interest is longwave troughing with both GEFS/EPS exhibiting some agreement (there will be troughing) however timing is different, and details unclear/not even worth discussing so far out. Given yet another frontal intrusion with the upcoming system, looks like the next system, unless significant slowing occurs (possible - models have trended substantially slower with the upcoming wave), what could be a strong surface system could go with nothing but light precipitation in the southern plains. Other than that, looks like a quiet period per most recent run of EPS weeklies, with EC troughing dominant again. Interestingly, the 12z GFS shows something that might have potential. Secondary cyclo. near the RR OK/TX border along dryline/cold front, with some interesting soundings. Link to comment Share on other sites More sharing options...
jojo762 Posted February 16, 2017 Share Posted February 16, 2017 The system late next week (thurs/Friday?) looks to be interesting if we can get some decent moisture return after the Sunday/Monday system... Link to comment Share on other sites More sharing options...
bjc0303 Posted February 16, 2017 Share Posted February 16, 2017 If the system can slow ~24 hours, maybe. The dynamics of the system look really impressive on both 06z deterministic GFS and 00z Euro. Large area of backed surface winds in the warm sector, along the dry line, etc. Transport of EML supporting steep lapse rates. Everything will be in place - except perhaps moisture. Gonna be interesting to watch. Don't get strong dynamics like that in S plains too often per year. Link to comment Share on other sites More sharing options...
jojo762 Posted February 16, 2017 Share Posted February 16, 2017 57 minutes ago, bjc0303 said: If the system can slow ~24 hours, maybe. The dynamics of the system look really impressive on both 06z deterministic GFS and 00z Euro. Large area of backed surface winds in the warm sector, along the dry line, etc. Transport of EML supporting steep lapse rates. Everything will be in place - except perhaps moisture. Gonna be interesting to watch. Don't get strong dynamics like that in S plains too often per year. Sure don't, at a glance it's a pretty incredible system for this time of year... If we get DPs around 60, somewhere, along with a slower system, things could really start popping with the current progged wind field. Something to watch, at least. Link to comment Share on other sites More sharing options...
bjc0303 Posted February 17, 2017 Share Posted February 17, 2017 Disappointing to see such a potent system will likely pass through with no favorable moisture. Given a respectable return flow scenario, this is a possible tornado outbreak from OK into KS. GFS and ECMWF trend drier, but trend upward with shear. Oh well. Link to comment Share on other sites More sharing options...
bjc0303 Posted February 21, 2017 Share Posted February 21, 2017 Seems like with recent rains, and more importantly, the early greening on the large scale, and GOMEX conditions, that the potential will exist for a somewhat earlier start to the severe weather season, or at least a brief period early next week where active weather takes place. Current GFS forecasts low 60s dewpoints to reach southern/central OK by next Monday. Some ensemble members become more unstable. The Euro is a little less progressive than the GFS and has low-mid 60s dewpoints in OK by Tuesday. Both depict similar setups, with a NE-SW oriented dry line owing to an SW-NE oriented jet streak aloft/SW flow aloft, but shear profiles look impressive nonetheless. Deterministic Euro is currently significantly more unstable than the deterministic GFS. Interesting to see how things unfold... Even a mix of the two models would yield bulk shear ranging in the 50s-60s, 0-1 km SRH 200+, and SBCAPE 1000-1500 j/kg. Link to comment Share on other sites More sharing options...
jojo762 Posted February 22, 2017 Share Posted February 22, 2017 Tulsa sure seems interested in the time period discussed above... " Our area will remain in the jet stream flow at the base of broad cyclonic flow over the western 2/3rds of the nation going into next week. A pair of fast moving waves embedded in this flow will bring thunderstorm potential to our area. The first wave will affect the region mainly Sunday night. What is different this morning compared to yesterday is the expected northward expansion of the warm sector in the wake of the weekend cold. The latest ECMWF suggests the warm front will lift north to around the Red River, leaving our area in the favorable warm advection/elevated storm region. Our area should be in the warm sector for the second wave Tuesday. The best chances for storms will be with the front late Tuesday/Tuesday night, though some potential exists during the day ahead of the boundary. The setup will be favorable for all modes of severe weather. The forecast could change, considering this is still 6 days out. Stay tuned to the latest updates as we get closer to the event." Link to comment Share on other sites More sharing options...
bjc0303 Posted February 22, 2017 Share Posted February 22, 2017 00z and 12z Euro advect 60s dewpoints into central/eastern OK ahead of an eastward mixing dry line. winds back to S/SE towards 00z. I'm not even going to address the GFS because it is so 1) inconsistent and 2) crappy, so it's a very low confidence forecast (hence predictability too low). However, playing around with a GFS sounding on sharpPy to incorporate what I would anticipate given the ECMWF thermodynamic and kinematic progged profiles, almost verbatim, would yield 1000-1500 MLCAPE, maybe higher, juxtaposed with strong deep layer shear, strong low level shear, etc... with initiation likely occurring just to the west of I-35. Plenty could and probably will change, but the Euro suggests a pretty intriguing event. I definitely have my eyes on it. Unlike past few systems this one looks to have substantial moisture return aided by an ejecting wave/speed max ahead of the main system that, while producing some overnight convection, doesn't obliterate or mess up the warm sector and helps accelerate low level flow in anticipation of the main wave. Probably too much in terms of details this far out, but I think there will be a severe weather event next week. Moisture return and timing of upper level/associated low level response will be key. Link to comment Share on other sites More sharing options...
andyhb Posted February 23, 2017 Author Share Posted February 23, 2017 Really going to come down to the strength/amplification of that polar shortwave dropping out of the Pacific NW and the incorporation of the ULL that is currently driving a rex block over AK and the Aleutians. This will largely determine whether the thing ejects in pieces and gets sheared out by the confluence resulting from the SE ridge (or the fact that the northern and southern streams are out of phase). Euro has definitely been raising my eyebrows for the past few runs though although the extent of the effective warm sector shrank a bit along with the strength of the LLJ with the 12z run. Chiclet chart earlier was hitting next week hard, with the strongest hit being Tuesday unsurprisingly. Link to comment Share on other sites More sharing options...
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