General Weather Discussion - April 2015

[venture]

Today

Marginal Risk today over Northern OK and Western OK. Early morning convection will likely cause today to be a mess, if it develops. Currently some showers/storms moving through from Central back to SW OK. Looks like another late night complex of storms will form in the Northern Panhandle and move over OK through the overnight, reaching the metro around 3AM on Wednesday. Moisture return today is looking to be pretty meh. CAPE during peak heating looks to only get up to 1500 to 1800 j/kg.

Wednesday

Enhanced Risk expanded to cover SW OK and also the southern part of the metro, back to the south and east along the Red River. Slight Risk surrounds it, with a marginal risk north of that. GFS appears to be favored model from SPC that develops storms early over Central OK along the warm front. By afternoon it continues these storms and increases them, but also gets a complex fired over in SW OK. Early convection is going to impact how the afternoon plays out so right now it is going to be a sloppy forecast with high bust potential. It should be noted that looking at GFS's forecast sounding over OKC at 4PM highlights a very favorable wind profile for rotating storms. If we get more heating to get higher instability, supercells with large hail and tornadoes would be very plausible.

Thursday

Not much, except maybe some storms along the Red River.

Friday

A lot of uncertainty still. Neg tilt trough will move through, but Euro has sped up slightly getting it through by early afternoon. GFS still very fast in getting Central OK cleared out. At this point SPC has not outline dit yet, but is closely monitoring.

[s00nr1]

Keep an eye on late next week and weekend....

[Bobby821]

Keep an eye on late next week and weekend....

Are you referring to next week and weekend as the week of the 27th?

Also any new info about tomorrows storms for the metro and the storms for Friday?

[venture]

Are you referring to next week and weekend as the week of the 27th?

Also any new info about tomorrows storms for the metro and the storms for Friday?

Time wise for Friday is still a little iffy. 12Z Euro slowed the dryline down some and has storms firing right over the I-35 corridor (or just west) by 5-7PM.

[Dessert Fox]

I'm no meteorologist, so excuse me if this sounds dumb but..I've noticed everybody talking about the Euro(which I've never really seen play a big part in anything). I've heard nothing about the NAM. What are the GFS and NAM saying?

[venture]

I'm no meteorologist, so excuse me if this sounds dumb but..I've noticed everybody talking about the Euro(which I've never really seen play a big part in anything). I've heard nothing about the NAM. What are the GFS and NAM saying?

Euro was ruled the favorite by the forecasting heads by having the least initialization issues when the run was starting. Essentially it was grasping what was happening at its start time better than the others.

Euro is the slowest out of the 3 we are talking about here. GFS is the fastest with the dryline already at or just past Shawnee at 4PM. On NAM the dryline should be right over I-35 at 4PM.

NAM hasn't got a lot of talk because it only goes out 84 hours...so it just started covering Friday. With two runs under its belt, it has slowed the dryline about 30 miles for the 4PM forecast window.

[Ginkasa]

It needs to be done in time for H&8th or be well after. I plan on going this Friday and I don't often get a chance.

[Anonymous.]

Should see storms develop over the next couple hours from NW OK into C OK and slide ESE. Should be garden variety and not severe.

[venture]

Gray hair inducing forecast coming up...let's see how badly I fubar this one.

Wednesday

Severe risk is there for today, but it is all dependent on overnight activity through the morning hours. Storms should start to form around 1AM, which there are some signs of this happening in the Northern TX PH. These should ride eastward and then southeast to near OKC during the morning hours. These should put out an outflow boundary and also help the front drop further south. Wherever this front ends up will determine the northern extent of severe weather for today. 00Z NAM pushes it south early and then back north as a warm front in the afternoon. Storms forecast to initiate (on NAM) between Chickasha and Lawton. Movement will then be southeast. 03Z HRRR shows the same movement with the boundaries but also keeps instability low through late morning and afternoon due to on going/early convection.

Thursday

Small area of Southwest or South Central Oklahoma will be fairly unstable and have the chance for a storm or two to go up. Severe weather possible. 00Z NAM has storms possible after 7PM in that area, so might see one or two grumpy storms go up.

Friday

Everything is completely dependent on position of the dryline in the afternoon. If it gets to your east, you are good. If it is still to your west, watch out. 00Z NAM has the dryline over Western OK at 4PM, but nothing extremely sharp. The 55 degree dewpoint line is around US 183. The 60 degree line around US 81. Some hint of a dryline budget near Lawton at this time. The dryline then stalls and sharpens over I-35 around 10PM. It then slowly begins moving east again through the overnight hours, reaching eastern OK by daybreak. 00Z GFS has the dryline bulging through OKC by 4PM to where it is just east of the Metro area. It slows it down around the same time as NAM, but closer to a Tulsa to Ada line. 00Z Euro isn't in yet, so will need to update after that run.

The whole setup Friday is fairly primed for a high end event. However there are variables which will hopefully clear up with these upcoming model runs. Ahead of the dryline wind profiles will be favorable and as the LLJ increase, the tornado threat will increase to favor even strong tornadoes. At night. Which isn't good. So we will be watching the dryline position like a hawk as if it is running slower than expected, it could put OKC into play. As May 2013 proved, it doesn't take a long time with the right conditions for a storm to pop up and tornado and produce a strong tornado.

Additional severe weather possible on Sunday over Central and Eastern OK, but most on that later this week as we get closer.

[venture]

SPC DAY 1 Outlook is updated to finally fall in line with how models have been handling today.

ENHANCED risk along the Red River counties in Southern OK.
SLIGHT risk from Sayre to Chickasha to Ada to McAlester.
MARGINAL risk from Arnett to Guthrie to Muskogee.

SPC DAY 2 Outlook updated as well and falls in line with what I was mentioning earlier.

SLIGHT risk over parts of Southwest, Central, and South Central OK - as far north of Chickasha over to Pauls Valley.
MARGINAL risk further north over the rest of SW, Central, and Southeast OK.

[jn1780]

Looks like so far for Friday SPC has West Central all the way to east Oklahoma under a slight risk. There is a enhanced risk up in Kansas.

[BoulderSooner]

Some great rain so far today

[Pete]

Love the thunder and lightening! Oh how I've missed it.

[Dessert Fox]

9 is saying there's a possibility of the storm system coming out in the morning instead of the afternoon. Thoughts?

[venture]

9 is saying there's a possibility of the storm system coming out in the morning instead of the afternoon. Thoughts?

For what day? That is pretty vague when we have multiple days we are talking about here.

[Dessert Fox]

For what day? That is pretty vague when we have multiple days we are talking about here.

Oh, I apologize. I meant Friday.

[SoonerDave]

Oh, I apologize. I meant Friday.

That's part of the uncertainty Venture and even the TV guys have been discussing because the models don't quite agree.

One way or the other, the potential storm severity is highest east of the dryline. The worst of the heating is typically in the afternoon, so if the dryline passes the OKC area in the morning, the storm potential drops fairly substantially. On the other hand, if it slows down, and the air gets sufficiently destabilized, you'll have ingredients for a possibly significant storm setup Friday afternoon.

There's just no way to say which model will prove "least wrong" at this point. An earlier pass for the storm would be the best to mitigate severe weather.

[venture]

So here are my thoughts for today. Pictures first...



Current radar image is upper left showing existing boundaries. I also drew them on the satellite image which is below the radar. On going showers and a few storms along the cold front in Central and Eastern OK. The front right now (as far as the Metro area is concerned) is from Cogar to Minco to Tuttle to Moore to Tecumseh. It is slowly moving south. The big question today is how far south does the front go. HRRR takes it just south of Norman but then brings wind back from the Southeast later this afternoon and early evening - which tends to suggest the boundary is back to our north. This also could be in response to more localized / mesoscale activity that will be impacting wind patterns and such.

Center part of the image above has the latest SPC outlook for today, Dewpoints, and then solar radiation showing where the sun is out and baking. Over to the right are images from the HRRR for 4PM today. First is CAPE showing moderate to high instability south of the front. It also shows developings storms in Western OK and the TX PH. By 7PM we are looking at the following...



A few isolated supercells moving through the area, including one going through the very southern sections of the Metro area. If these develop...



HRRR is showing they will likely be rotating storms which would be risks of large hail and tornadoes with them. I'm a little leery about the chances of a storm surviving in Central OK due to the morning storms and of course some what uncertain as to how far south the front will get. I've outlined in red on the satellite image above the area I feel is most likely to see severe weather in the state today.

[adaniel]

I can tell you the hype machine is in full force in DFW today. Our first enhanced/moderate day at least since I've been here, so that is to be expected.

What are the weather conditions looking like down here, venture or anon? It seems like most of the storms are going to stay in OK based on those maps.

[bchris02]

Damon Lane is really starting to hype up Friday.

[LocoAko]

Damon Lane is really starting to hype up Friday.

From what I've looked at for Friday, it could be quite a day but as of now (and this could easily change) the dryline looks to sharpen up and set up just east of the metro (say, a N-S line going through Shawnee). Northeast Oklahoma around Tulsa and up into Southeast KS look particularly dangerous as of now, though it should be emphasized there are still remaining uncertainties to clear up that could easily mess up an 'outbreak'.

[bchris02]

From what I've looked at for Friday, it could be quite a day but as of now (and this could easily change) the dryline looks to sharpen up and set up just east of the metro (say, a N-S line going through Shawnee). Northeast Oklahoma around Tulsa and up into Southeast KS look particularly dangerous as of now, though it should be emphasized there are still remaining uncertainties to clear up that could easily mess up an 'outbreak'.

I remember when Reed Timmer said last year it was looking to be the outbreak of the century, but it ended up being a bust.

[venture]

I remember when Reed Timmer said last year it was looking to be the outbreak of the century, but it ended up being a bust.

That's why you don't pay attention to people that make a living getting people hyped up.

[Romulack]

Could this have any effect on storms that move from southwest Oklahoma into the OKC metro?
Lawton cleared to begin cloud seeding | The Lawton Constitution

[SOONER8693]

That's why you don't pay attention to people that make a living getting people hyped up.

I've reached the point that I believe most all of the tv weather people are "fear mongers". They want to keep people afraid, so they can keep themselves as the center of everyones attention. Basically everyone in this state will now be hanging on every word Morgasm, David "tornado on the ground" boy, and others have to say at least until Friday. Then they will start it all again. It almost seems criminal what they do, and no one calls them on it.