General Weather Discussion - April 2016

[jn1780]

I never thought I'd actually say much if anything positive about AT's style, but I must admit that's a pretty balanced, reasonable, detailed explanation of what's up. Very much non-hyped as well.

I wonder if the Euro models that are starting to suggest the possibility of the dry-air mixdown are causing ALL the local TV mets to hedge their bets at least a bit. Anon, care to comment? Would love to hear Venture's thoughts as well...DARN him for moving away.

They are probably thinking that they can't out doom Morgan so why try? He has the fear market cornered.

[Bobby821]

This was posted at 11:00am 4/22/2016 on channel 5's website.

Severe weather outbreak looks more likely next week | Oklahoma City - OKC - KOCO.com

[SoonerDave]

I like this KWTV graphic a lot….. It shows some rather serious and ominous information but because it was presented with calming words it didn’t upset the people who are prone to being upset about WX…. But if you knew something about what this information might mean for our future weather potential and were prone to Lilapsophobia it might be upsetting?

I thought this graphic was great as well. It had actual meteorological information - instability/shear/jetstream/lift - presented in what I'd call an "audience-conscious" context. No fake jargon, no hype. I think it was very well thought out *and* presented. You could *easily* turn this kind of graphic into a doomer/gloomer presentation, but they didn't. As I said before, major props to KWTV. This is good stuff.

[tfvc.org]

And this morning's forecast with Lacey Swope/Jed Castles actually talked about the kinds of ingredients that have to be present - VERY informative, great balance of real met terminology with really no hype *at all*. No "TORCON INDEX" and no "Red Maps of Death." Swope was *very* cautious in saying, effectively "these are the kinds of ingredients, they're going to be present, but it's still several days out. Just keep this in the back of your mind as you plan for next Tuesday."

I don't think you could ask for a better-delivered severe forecast than that. Provide the information. Qualify the information. Encourage people to be informed.

Five-star props to KWTV in my book.

That is why I really liked Mike Armstrong. I liked his "geeky" explanations of things. I honestly think that he should have been chief, but I think David had seniority over him.

[Anonymous.]

NAM is popping 3 supercells tomorrow in W OK. Large hail looks likely with any development.

[Dessert Fox]

Any update on Tuesday?

[Bobby821]

Any update on Tuesday?

From NWS Today:

TUESDAY STILL HAS THE POTENTIAL TO BE A SIGNIFICANT SEVERE
WEATHER DAY. CURRENTLY...CONSENSUS INDICATES THE
DRYLINE/CONVECTIVE INITIATION WOULD BE JUST WEST OF I-35 TUESDAY
AFTERNOON. FORECAST INSTABILITY AND EFFECTIVE BULK SHEAR WILL BE
MORE THAN SUFFICIENT FOR SUPERCELLS. MODERATE TO HIGH INSTABILITY
AND VERY STEEP MID- LEVEL LAPSE RATES INDICATE THE POTENTIAL FOR
SIGNIFICANT TO GIANT HAIL. LOW-LEVEL MOISTURE PROFILES SUGGEST THE
TORNADO RISK MAY INCREASE AS THE STORMS PROGRESS EASTWARD INTO
LOWER LCL HEIGHTS.

THE GREATEST FORECAST UNCERTAINTIES ARE THE TIMING OF THE TROUGH
AND THE LOCATION OF THE DRYLINE. CURRENT FORECAST LEANS TOWARD THE
GFS AND ECMWF SOLUTIONS. THE LATEST NAM IS SLOWER THAN BOTH THE
OPERATIONAL GFS AND ECMWF WITH THE APPROACHING TROUGH...WITH A
SLIGHT DISPLACEMENT IN SURFACE/UPPER LEVEL FEATURES. THE TIMING OF
THE TROUGH WILL DEPEND ON THE AMPLITUDE OF THE DOWNSTREAM
SHORTWAVE RIDGE. THEREFORE...THERE MIGHT SOME VARIATIONS/SHIFTS IN
THE FORECAST...BUT BOTTOM LINE...BE PREPARED FOR POTENTIALLY
SIGNIFICANT SEVERE WEATHER ACROSS PARTS OF OKLAHOMA AND WESTERN
NORTH TEXAS TUESDAY.

BEYOND TUESDAY...AN UNSETTLED PATTERN WILL CONTINUE ACROSS THE
REGION. SEVERE WEATHER POTENTIAL WILL CONTINUE ACROSS SOUTHEAST
OKLAHOMA ON WEDNESDAY..ESPECIALLY EARLY IN THE DAY.

A BRIEF BREAK APPEARS POSSIBLE LATER WEDNESDAY INTO THURSDAY WITH
SOME SHORTWAVE RIDGING.

ISENTROPIC ASCENT LATE THURSDAY INTO FRIDAY MAY RESULT IN
WIDESPREAD/HEAVY RAINFALL ACROSS THE REGION. FLOODING/FLASH
FLOODING COULD BECOME AN INCREASING CONCERN IN THIS PERIOD. SEVERE
WEATHER WILL REMAIN POSSIBLE...HOWEVER...WIDESPREAD CONVECTION
SHOULD MITIGATE THE OVERALL SEVERE THREAT.

THE NEXT POTENTIALLY SIGNIFICANT DAY FOR SEVERE WEATHER MIGHT BE
SATURDAY AS ANOTHER SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW
APPROACHES THE REGION. IT IS TOO EARLY FOR SPECIFICS THIS FAR
OUT....BUT AN ACTIVE PATTERN WILL CONTINUE INTO THE END OF THE
WEEK.

[LocoAko]

NAM is popping 3 supercells tomorrow in W OK. Large hail looks likely with any development.

I was surprised to see the 12Z SPC WRF develop supercells all the way down into SW OK tracking ENE by tomorrow evening when most of the threat has been expected to be in northern OK. Just one piece of guidance, but like the discussion from the NWS notes, there's still disagreement about the southward extent of the threat.

[John1744]

Surely things aren't looking that bad are they?

[jn1780]

Surely things aren't looking that bad are they?

I haven't seen this strongly worden language he is referring to. The last for cast discussen from Norman actually has a whole paragraph talking about uncertainties with the timing.

It wouldnt surprise me if they go with just a slight risk on the day 3 outlook tomorrow based on uncertainly.

[LocoAko]

I haven't seen this strongly worden language he is referring to. The last for cast discussen from Norman actually has a whole paragraph talking about uncertainties with the timing.

It wouldnt surprise me if they go with just a slight risk on the day 3 outlook tomorrow based on uncertainly.

It's technically the first time SPC has used the word "outbreak" on a Day 6 outlook, so that does imply a very serious situation, though I personally think Sowder's description is slightly hyperbolic. It is a very high end setup, but there are still some things that need to come together to make it worst ever, etc.

[bchris02]

It's technically the first time SPC has used the word "outbreak" on a Day 6 outlook, so that does imply a very serious situation, though I personally think Sowder's description is slightly hyperbolic. It is a very high end setup, but there are still some things that need to come together to make it worst ever, etc.

What's your opinion on dryline placement? In terms of OKC impact, that is going to be key. Worst-case scenario would be for it to set up somewhere around El Reno. Better would be in far western Oklahoma, giving storms that develop time to merge into a squall line before reaching the metro or along I-35, in which greatest impact would be east of the metro. I don't want anybody to be hit, but if tornadoes have to happen, its best they stay away from densely populated areas.

[Anonymous.]

I was surprised to see the 12Z SPC WRF develop supercells all the way down into SW OK tracking ENE by tomorrow evening when most of the threat has been expected to be in northern OK. Just one piece of guidance, but like the discussion from the NWS notes, there's still disagreement about the southward extent of the threat.

HRRR isn't buying anything south of C KS today. That WRF run showing those monster hailers in W OK seems outlying, but we will see what the CU fields say this afternoon.

[Anonymous.]

[bchris02]

Aaron Tuttle has mentioned the possibility of dry air filtering into western Oklahoma on Tuesday, pushing the prime tornado threat east of I-35. I really hope that's the case. I don't want to see anybody get hit but its Oklahoma and its springtime so there has to be tornadoes. With that in mind, it's best if they happen in primarily rural areas rather than in OKC.

[ou48A]

As conditions continue to trend toward a very serious threat on Tuesday afternoon and as the forecast become more into focus it would be prudent IMO to make the decision on Monday evening to cancel activity’s and send as many people home from work / school as possible Tuesday before the expected threat time period.

We don’t need clogged interstates / streets and people in places with poor shelters when the storms hit.

[Dessert Fox]

Aaron Tuttle has mentioned the possibility of dry air filtering into western Oklahoma on Tuesday, pushing the prime tornado threat east of I-35. I really hope that's the case. I don't want to see anybody get hit but its Oklahoma and its springtime so there has to be tornadoes. With that in mind, it's best if they happen in primarily rural areas rather than in OKC.

Severe Storm Forecasting - Tornadoes Tuesday? - ATs Weather

An update.

[Dessert Fox]

Very surprised the SPC upgraded to a MDT and mentioned a high risk with all of the problems this set up has or, could have.

I'm thinking it could possibly be more because of hail, excluding the triple point.

I'd love your input Anon.

[SoonerDave]

If I'm reading the SPC"s summary for tomorrow correctly, there are several variables that are in play for this development tomorrow - dryline timing/placement (which, I guess, is always the case), but also the possible development of two regions of storm - one in mid/N Central OK, and then another in N/NW Texas, both regions moving NNE very rapidly. They also talk about giant hail, as Dessert noted, and that may well be why they upgraded to a moderate....The 70's dewpoints are a big deal to me - mid/high 60's are normally fuel enough, but mid 70's are pretty stout fuel.

[LakeEffect]

Solid points on the reasoning for the upgrade to moderate. I think too many people equate higher risk w/ tornadoes, even though it's simply a stated risk of severe storms, which could mean hail, wind, or tornadoes... or a combination thereof.

[Anonymous.]

So the way tomorrow is looking, is the chance of a bust scenario for central OK is decently present. The timing of the low ejecting may result in a lack of adequate lift to get storms going until maybe east of I-35. Models are hinting at this scenario and exploding storms basically right after the main dryline push east of I-35. However this is almost impossible to forecast because we have to see where the dryline sets up tomorrow and the exact timing of the low across KS/NEB.

There is also the possibility of the opposite scenario in which the dryline forcing is lagged behind and results in a more tilted dryline somewhere in WC OK. This scenario would obviously be more threatening to the populated areas in C OK, as storms would have time to mature before traversing ENE across the state.

At this time, I would not be surprised to see the MODERATE risk expanded south and east into N/NE TX. Also I think a HIGH risk will be placed somewhere in C KS.

[John1744]

They expanded the moderate area it seems.

[Anonymous.]

May have a stray storm or two that develops on a slight bulge I see on the dryline out in W OK this afternoon. North of Clinton area. Chance of development is extremely low, but if development occurs, severe is likely.

[SoonerDave]

Reading a few bits here and there that lots of concern being focused in the Wichita area and immed. east. I-35 corridor the real hotspot, making that dryline timing even more important.

[Anonymous.]

Latest NAM is in. Fires dryline west of I-35, suggesting a possible refire heading into nighttime.