nrgjeff

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.

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.

Nice work Quincy! Looking back at my Colorado post, I kind of brushed over the main outflow boundary buried south (in West Texas). Subtle other boundary lifted north for the Trinidad TOR. However it was the main OFB (farther south) from the Oklahoma MCS that lifted north through AMA. With enough upper air support, and a responding LLJ, enjoy Texas Panhandle magic.

The MCC in Oklahoma has created a train wreck this morning (Monday). Still a chance things recover in Colorado; note 12 hours of sunlight to go as I type. Temps/Dews should be adequate by late afternoon. LLJ looks just-in-time JIT but tries late afternoon. With the main outflow boundary buried to the south Palmer Divide topography may have to work on its own. Outflow lifting back north may be better aligned with Raton Mesa topography late this afternoon. Despite JIT recovery, I think it is at least a local set-up in Colorado.

GFS ensembles and CFS weeklies should be available at NCEP or many free models sites. Euro ensembles and Euro weeklies usually require a subscription somewhere. Euro op is starting to show up on a few free sites though.

Both weeklies and some of the 11-15 day ensembles are starting to hint at a new trough in the Rockies. Some have it unseasonably south. Others have things northern Plains and Upper Midwest which is June Nino-ish. Either way a chaser has to like about a third of the way into June. North would be nice with smaller crowds.

Next week looks like some good storm chasing. Note I do not call for a big outbreak, but I see 3-4 chase days out of a 7 day stretch. Rockies trough is forecast to send out shortwaves for several days. Yes, sounds like SPC is teeing up. Sunday starts with short-wave ridging early but some southern stream jet energy pokes out over the Panhandles late. LLJ responds too. If enough moisture can return in time Sunday evening could be an appetizer. Monday and/or Tuesday should have some better moisture and wind shear, plus some surface boundaries to locally enhance SRH. Upper level wind fields are not particularly strong, but likely will be plenty for late May. Quality LLJ is forecast away from contamination. Plus no VBV is forecast. One can be reasonably confident that holds with WSW flow upstairs and open waves. If a stronger wave ejects Monday, then Tuesday could be an in between day. Tough to discern this far out. Wednesday or Thursday could go again. New shortwave is shown coming out sometime the middle of next week. Timing is variable run-to-run but the broad pattern is consistent. Perhaps Friday or Saturday something else comes out. For now I like Sunday-midweek.

Don't forget to check winds upstairs. Look for southwest winds at 500 mb and 200 mb; west is even better at 200 mb. Look for nearly straight south at 850 mb, SSE is even better. I wrote a lot more in the May 7-9 severe thread page 26. At any rate the 12Z GFS in on board with winds, and with low press and fronts in the central Plains. Lots of rain shown before peak heating, but it is days away...

In addition to climo improving for severe after April 15, a couple other reasons to be optimistic are noted. Pacific upstream situation should favor a transition to warmer zonal flow in the US, at first. Some of the weekly models hint a West trough later in April. Need to avoid the tear drop trash and get some real open troughs. Time will tell.

I bet Frozen Head is great with fall color too. We have it on our list next year. Tough call because I figure it peaks the same time as some other favorites. Tie might go to visiting somewhere new. So many choices, we are blessed to live in Tennessee!

I agree with Andy. Models are probably too pessimistic due to clouds etc. However the system is very dynamic. It should over achieve. Look at the wind fields. SPC is right to go ENH for sure.

Ice storms are stressful at work so I voted no; otherwise, I would have voted light since it is pretty. On days you can get sunshine while ice is still on trees, it is a spectacular treat. Still, the day before was probably stressful at work, lol. Here is a detailed rank of weather for me: 1. Snow in the South - very special 2. Tornado chasing - never being chased 3. Hail, medium size - exciting but not damaging 4. Snow in the North - more routine 5. Sleet, with the hope of lightning 6. Straight line thunderstorm wind esp with good shelfie 7. Warm Sunshine 8. Dust storm - interesting but annoying 9. Heavy hoar frost or rime icing is pretty. 10. Freezing rain can be pretty. Worst weather: Flooding impacts too many lives too much. Low overcast is depressing with no precip.

Today could be a pleasant surprise in parts of Kansas, if one enjoys severe weather. Agree with SPC on the big hail threat, but a brief rope or two may spin up too. Small scale set-up, enhanced by an outflow boundary OFB, was not really apparent until this morning. Dewpoints of 60 degrees are forecast to make it back to the intersection of the OFB and sagging synoptic front in west-central Kansas before mixing back out slightly. Still better moisture may be found in north-central Kansas where it won't mix out as much. Upper level winds are seasonable, and enough. LLJ has a slight response to subtle short-wave coming out of the Rockies on water vapor images. Should at least start out discrete in Kansas this afternoon. I'd favor the one or two OFB storms.

Total Solar in 2017 requires booking a few motel rooms along the route, a hedge against weather. Make sure they have good cancel rules; then, cancel all but one when the forecast becomes clear. We get another long track total solar across the Continental US in 2024 and I plan on seeing both. I would recommend chaser mentality, even with the certain forecast. Plan ahead for obstacles, traffic, overzealous police, dueling banjos, or whatever else might come up. Cheers!

Also, some model agreement is noted in the 11-15 day for a trough West ridge Midwest pattern. I'm talking end of August and first few days of September. Hints of both upper and low level jets responding is shown in the Plains some of the days. Northern stream staying active through the summer helps the case.

That outflow boundary from KC to Omaha will provide great low level helicity. It should be a late show, as the atmo takes all afternoon to recover, but it'll go. Also note the southern most cell may not be the cell of interest today. Boundary intersection is northwest. It will be tough to know the right cell until after things start. Subtle setups favor the lucky. LOL at the morning story out of Leawood. Yeah, nobody there goes to shelter for severe warnings. Maybe for tornado warning, but even then too many people go outside for a look.

KC area scores a classic northwest flow tornado. If you mentally rotate the upper air charts counter-clockwise 45 degrees, it looks like the ATMO 101 textbook setup. Frankly I'm a little disappointed in myself not going home during a holiday week. Oh well. At least my Facebook feed was very alive last night, with weather for a change!

12Z NAM (6/10) expands Thursday area of interest south to the KS/OK border. We'll see what SPC thinks in about an hour. Friday looks like SLGT not MRGL, but we'll see. GFS concurs on wind fields but not qpf; I tend to favor hi-res NAM for qpf. Thursday still looks ok in Iowa but storm mode and ongoing rain will be challenges. Shortwave timing is also an issue, but low level turning should remain near OFBs. Now appears new shortwave ejects into High Plains in time Thursday afternoon, with no midday rain. Cap may hold in the TX Panhandle. Hailers may develop but a hot 700 mb looks to kill them shortly after 00Z. Meanwhile DL and SF intersect in southwest Kansas, under slightly less of a cap. Synoptic front must act as stationary or warm; a CF surge would destroy that set-up. Low level shear is less than ideal, but looks like 50kt+ upstairs. Could a boundary intersection get the job done? Friday looks complicated. Upper shear relaxes a bit, but an upper low sits over CO/NM. One would expect downstream agitation in the Panhandles. CF surge remains a risk; however, low press appears to promote better low level wind backing. It is the Panhandle in June.

This week is well handled in the short-term thread. After perhaps a relatively quiet 6-10 day, always some little local events in June, things may become more active again the middle of June. MJO is forecast to perk up in Region 4-5 by some models. Others have the MJO going back to sleep. Region 4-5 is favorable for a Pac NW trough. Even the models that put the MJO back to sleep introduce the said trough late in the 11-15 day period. All 3 agree on the feature. Jet stream energy punches into the Pac NW. Downstream ridge is depicted over the Upper Midwest. All of the above is favorable for the northern High Plains. EDIT: June 4 probably needs to be added to the short-term thread dates. 12Z GFS/Euro both paint excellent chase days this Wednesday and Thursday. Moderate speed shear combines with high CAPE and quality low level turning. EML may finally limit junkvection and promote more chasable events.

Ian you are golden. GFS stands for curse words. Euro and Canadian keep warm sector in tact for next weekend. Both their ensemble products maintain the North American pattern into the 11-15. Euro weeklies and CFS maintain into early June. I think you get all that data, but just a reminder everything but a crappy op model is on your side. I'm reluctantly letting this weekend go based on long travel and odds. Tornadoes will verify today and tomorrow, but terrain issues are noted in NE/SD today. Tomorrow target is so diffuse I'm not betting a 700-800 mi drive on anywhere. However for those already out there, tomorrow will verify. Kansas sups may have issues with poor inflow and/or bad hodos. Eastern OK could go on the OFB with excellent shear but terrain could be an issue. Bust activity: Talimena Parkway is a gorgeous scenic drive. Lead up to Memorial Day could end up wet too. However I know this weekend is a mess. There is still hope for next. Much of next week a broad West trough is in place ejecting occasional short-waves. Each time a 250 mb jet comes out the LLJ at 850/925 mb responds. If a main target rainout, upslope would probably verify. It will work out one way or another. Late May climo favors tornadoes. Beyond that a recurving Pacific typhoon could have impacts. However Euro/Canadian ensembles do not echo GFS ens pattern change. Either the typhoon is not strong enough, or it just gets absorbed into a mid-latitude system within the already established buffet line of Pacific systems. Good to go!

Word of caution: Recurving Pacific typhoon, SOI drop, and increasing GLAAM could mix up the pattern. All that said the ensembles may be jumping the gun. Looks good through Memorial Day, even if more upslope than classic.

Yes all 3 ensemble suites hint at a less meridonal upper level jet ahead of Memorial Day. They also show LLJ responses. This coming weekend of May 15-16 will be great; but, if you can't make it the lead-up to Memorial Day looks good too. Why do I have faith in a 10 day forecast? It is late May in the Plains. If all else fails and/or the trough teardrops again, upslope would verify. This is not like forecasting snow in the South. This is peak tornado season in the Plains.

This weekend does have a better trough than last models verbatim; that said, last week was a respectable sequence. Memorial Day could repeat yet again after these. Why all the bickering? State of the season remains strong. First, if the EML fails and/or ATMO gets overturned by morning convection, May climo indeed still favors chasers. One would simply modify target and/or philosophy. Shift south if maintaining OFB/DL reasoning. Shift north for broad upslope flow. Saturday worked out great for both. Second, this sequence less midday rain is forecast. Keep in mind morning rain ending is good for OBFs. That could change, but so far it does not look as messy. If upper winds are straight south and/or veer/back no problem. Just target upslope where one would expect 850 winds to be screaming and quite backed. Finally, the ceiling remains high if the short-wave can come out at the right time and with some southwest (vs south) winds upstairs. Last time never looked high risk at any point, due to teardrop trough, but there it at least a path to another MDT for tornadoes on Saturday. Similar thoughts are valid for the trough leading up to Memorial Day. Don't worry, be happy!

Rest of this week has indeed perked up. Wednesday through Saturday look like a possible sequence. While there may be a less active day Thursday or Friday, not both, Wednesday and Saturday are looking pretty good. Next week may set up again starting around midweek. Currently looks like a little shorter wavelength trough but with a better straight westerly jet stream. Jury is out on strength and low levels. Finally the following week of May 18th all ensembles (GFS, Euro, Canadian) have a new big western trough. Southwest below normal heights signal is consistent. Also the East keeps verifying warmer, which is another plus in the US weather pattern.