Even Mike Morgan had to give up on winter precip for OKC...There will be more storms to come Mike...More to come

Damn it. Maybe the clipper storm/new years apocalypse will happen. This is already on track to be the worst Christmas ever and the absence of winter weather pretty much is the last lump of coal in the stocking.

Even Mike Morgan had to give up on winter precip for OKC...There will be more storms to come Mike...More to comeMike Morgan also indicated the other day that water is incompressible, which is not entirly true.
Although difficult water can be compressed by a small % factor.

http://hyperphysics.phy-astr.gsu.edu/hbase/permot3.html

Special Weather Statement
Updated: Wed Dec-18-13 05:00pm CST
Effective: Wed Dec-18-13 05:00pm CST
Expires: Thu Dec-19-13 05:00am CST

Severity: Minor
Urgency: Expected
Certainty: Observed

Status: Actual
Type: Alert
Category: Met
Areas affected: Alfalfa; Atoka; Beckham; Blaine; Bryan; Caddo; Canadian; Carter; Cleveland; Coal; Comanche; Cotton; Custer; Dewey; Ellis; Garfield; Garvin; Grady; Grant; Greer; Harmon; Harper; Hughes; Jackson; Jefferson; Johnston; Kay; Kingfisher; Kiowa; Lincoln; Logan; Love; Major; Marshall; McClain; Murray; Noble; Oklahoma; Payne; Pontotoc; Pottawatomie; Roger Mills; Seminole; Stephens; Tillman; Wash ita; Woods; Woodward

Message summary: ...a winter storm expected to impact oklahoma and western north texas friday through sunday...
After a period of very warm weather...colder air will return to oklahoma and north texas thursday night into friday morning. Rain is expected to develop across western north texas and southwest oklahoma friday evening...as a strong storm system approaches. Rain is expected to spread north and east friday night into early saturday morning. Some of the rain across the northern third of oklahoma may freeze on elevated surfaces as temperatures will be in the upper 20s to lower 30s. On saturday...temperatures will be above freezing and any ice accumulation across northern oklahoma will melt. Another shot of cold air is expected saturday night and sunday. Therefore...snow and some freezing rain will be possible across the northern half of oklahoma. The best chance for winter weather will be across the northern third of oklahoma...where some locations may receive several inches of snow. The snowfall could affect travel conditions in some locations saturday night into monday. In addition to the winter precipitation... Heavy rainfall will be possible across south central and southeast oklahoma. After the storm...temperatures are expected to rise above freezing by monday...allowing for melting of any snow or ice accumulation. Please remain weather aware by listening to noaa weather radio...visiting our website and following us on facebook and twitter.

00Z Euro is almost completely in now, but it is in for the majority of this run. Some differences showing up, and I really expect today to be the day if we see any major changes to the model output. Let's be honest...the consistence and confidence in the forecast of this system has been in the toilet so far. Yes we've seen it go warmer recently with mostly all rain. That is the more likely scenario considering nearly all the models are showing some form of solution that revolves on it. With that said, I still exercise a bit of caution when dealing with a system like this that has been hard to handle. We've seen it many times where we have a couple situations take place.

1) Cold air positioning is completely miscalculated and the air gets in to place faster than expected.
2) What is forecast as a significant snow storm 3 days out by the models is quickly turned into a much weaker setup, or completely displaced somewhere else, on model runs only 12-24 hours out.

So now for some pictures. The image below is the air temp at the surface (well a couple meters up). The purple line is the 00Z Euro from yesterday, the pink is from 12Z yesterday afternoon, and the white is the one on the 00Z run tonight. This is the freezing line as predicted by the model. As we can see in just the time span of 24 hours it has move the cold air significantly further south especially on the west edge of this image. On the east side over in SE KS, it hasn't really moved at all. So this is showing some issues with handling of the cold air arrival over SW KS, the Panhandles, and W OK.

http://www.weatherspotlight.com/screencap/dec13/winstormdisc-4.png

Why is this significant?

Here is the QPF (precip) forecast for the same time around daybreak Saturday...the white line is a crude freezing line.

http://www.weatherspotlight.com/screencap/dec13/winstormdisc-4a.png

So what that signals is the risk of icing along/north of that freezing line. What about snow? Yes there very well could still be snow in the metro area. Right now it keeps it very low.

As I said yesterday or the day before, Thursday looks like the day when the models will make their big adjustments and get a good handle on things. The 06Z NAM is running now, 06Z GFS in a couple hours (I'm not staying up for them - sorry LOL)...so it will be interesting to see how they adjust compared to the Euro.

So Okc is at 51.75 inches of rainfall for the year. With this next storm it will move into the 2nd wettest year ever. But looks like we will end up short of the record which I believe is 56.95.

Leading edge of the cold air is already entering Nebraska this morning.

The model's snowfall placement is horridly inconsistent right now. Some in western KS, some in N OK, some in E KS.

GEM is also putting an icestorm over the northern 2/3 of OK right now.

It seems like the models have been more inconsistent than normal.... Is this true, and if so why?
Thanks

It seems like the models have been more inconsistent than normal.... Is this true, and if so why?
Thanks

I wouldn't say more so than normal. The previous snow event here was more the anomaly than what we see right now. Everything was locked in and agreeing 5+ days out...that normally doesn't happen.

The biggest issue with the models have been the handling of the closed low off the west coast, which those always give models fits. There just hasn't been anything definitive in push the low east for while now, but it'll start its march today. The models also have fairly limited upper air data to work with since the storm has been hugging the coast.

This forecast is a classic Oklahoma winter storm forecast.

We have potential for an extremely shallow cold air mass at the surface.
We have the battle of dryslot/wrap around.

Oh and we have no idea what will happen until it's occurring.

anonymous.... So your saying there is still a chance of us having a pretty decent winter storm here? What about in Tulsa?

This forecast is a classic Oklahoma winter storm forecast.

We have potential for an extremely shallow cold air mass at the surface.
We have the battle of dryslot/wrap around.

Oh and we have no idea what will happen until it's occurring.

We know what that means...

http://i34.tinypic.com/1g2g5k.png

This forecast is a classic Oklahoma winter storm forecast.

We have potential for an extremely shallow cold air mass at the surface.
We have the battle of dryslot/wrap around.

Oh and we have no idea what will happen until it's occurring.

No idea??? I think it's fairly clear there will not be a major winter storm in okc.

I'm going to make a bold prediction. It will be cold this weekend. We will either have rain, freezing rain, snow or nothing. You can take that to the bank.

No idea??? I think it's fairly clear there will not be a major winter storm in okc.

Honestly he's right. It is a pretty classic setup to allow for a fast moving layer of shallow cold air to screw the forecast up at the last minute. We've seen it many times before.

Some of the biggest storms we get aren't known a week ahead of time. Not saying it is likely for a significant winter storm for much of Oklahoma, but we've seen this setup before become a major ice/sleet situation. This is why climatology also needs to be part of forecasting.

I got the freezing rain section of the model compare page done - mostly. Helps to show the various solutions between them. Weather Spotlight - Model Comparisons - Freezing Rain (http://www.weatherspotlight.com/modelfrzrain.html)

The extreme is the GEM...
http://grib2.com/gem/WINTER_GEM_SFC_ACCUM-FZRN_84HR.gif

12Z Euro is in now...it is really cutting back on the amount of warm air (at the surface) being pulled north into the system. Moderate precip kicks in around here by 12:01AM Saturday...a couple things that I would find concerning.

Surface analysis... White line is the approx. location of where the freezing line *should* be for the duration of the heaviest precip. For the metro area that freezing line is running near Kingfisher down to El Reno. The red line that you see the surface dewpoint of 32°F. So that raises some concerns that any additional cooling with falling precip could actually push the surface temp to or below freezing across a good chunk of the metro area. So when we are trying to make a call on a rain/icing area...please keep in mind we are talking about a 28 mile distance from downtown OKC to El Reno. If you think forecast models can accurate predict the weather down to that small of a scale, I want what you smoke. :)

Even during the storm season the HRRR model which is one of my favorite always has great accuracy but still typically has a 50-75 mile margin of error with placements. So when Anon says this has the makings of a last minute call, he isn't joking around. This is why the model runs today and from here on out are going to need to be nit picked to see how they handle the cold air. Precip is going to fall - we go that. It comes down to a shallow layer of cold air rushing in.

http://www.weatherspotlight.com/screencap/dec13/winstormdisc-5.png

Precip Forecast...

http://www.weatherspotlight.com/screencap/dec13/winstormdisc-5a.png

NWS offices beginning to issue their advisories.

SW KS under WSWatch for 3-6" of snow (this is where models are putting snow axis).

E KS into NW MO WSWatch for 3-6" of snow.


No advisories for OK at this time, despite NWS in Norman changing their forecast to incorporate a slightly colder scenario, thus far.


EDIT:

And just a few minutes after posting this. OK has its first advisories:


NATIONAL WEATHER SERVICE NORMAN OK
316 PM CST THU DEC 19 2013

OKZ004>020-200530-
/O.NEW.KOUN.WS.A.0004.131221T0000Z-131222T1200Z/
HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-
NOBLE-ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-
INCLUDING THE CITIES OF...BUFFALO...ALVA...CHEROKEE...MEDFORD...
PONCA CITY...ARNETT...WOODWARD...FAIRVIEW...ENID...PERRY ...
CHEYENNE...TALOGA...WEATHERFORD...CLINTON...WATONG A...
KINGFISHER...GUTHRIE...STILLWATER
316 PM CST THU DEC 19 2013

...WINTER STORM WATCH IN EFFECT FROM FRIDAY EVENING THROUGH LATE
SATURDAY NIGHT...

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A WINTER STORM
WATCH...WHICH IS IN EFFECT FROM FRIDAY EVENING THROUGH LATE
SATURDAY NIGHT.


* TIMING: AREAS OF FREEZING RAIN ARE EXPECTED TO DEVELOP FRIDAY
EVENING THROUGH EARLY SATURDAY MORNING. ALTHOUGH SOME WARMING IS
POSSIBLE SATURDAY...BRIEFLY CHANGING FREEZING RAIN BACK TO
RAIN...A TRANSITION TO ALL SNOW IS EXPECTED LATE SATURDAY
AFTERNOON THROUGH LATE SATURDAY NIGHT.

* MAIN IMPACT: ICE ACCUMULATIONS ON TREES AND POWERLINES FRIDAY
NIGHT AND SATURDAY. DEVELOPMENT OF SLICK BRIDGES...OVERPASSES
AND WALKWAYS.

* OTHER IMPACTS: SLICK AND DANGEROUS ROAD CONDITIONS POSSIBLE
SATURDAY EVENING INTO SUNDAY...MAINLY OVER FAR NORTHERN
OKLAHOMA. HIGHEST SNOW TOTALS ARE EXPECTED OVER FAR NORTHWEST
OKLAHOMA WHERE UP TO 4 INCHES POSSIBLE BY DAYBREAK SUNDAY.


This is basically all of NW OK and NC OK (Norman viewing area).

Logan and Kingfisher counties in the metro area are the one two in it, but I just refer back the 12Z Euro discussion and how things can keep evolving. We aren't 100% out of it here in the Central and Southern Metro area.

http://www.mesonet.org/data/public/noaa/wwa/maps/realtime/latest.oklahoma.winter.gif

Honestly he's right. It is a pretty classic setup to allow for a fast moving layer of shallow cold air to screw the forecast up at the last minute. We've seen it many times before.

Some of the biggest storms we get aren't known a week ahead of time. Not saying it is likely for a significant winter storm for much of Oklahoma, but we've seen this setup before become a major ice/sleet situation. This is why climatology also needs to be part of forecasting.

Ok. But when it comes to freezing rain shouldn't the temp be around 28 or 29 to cause problems? 31 or even 30 is not that big of deal right?

Ok. But when it comes to freezing rain shouldn't the temp be around 28 or 29 to cause problems? 31 or even 30 is not that big of deal right?

It depends. For ground ice accumulation once you get to 30 it tends to kick into high gear...but I've seen plenty of road icing at 31 and 32. Also at 30 or 31 accumulation on vegetation is in full swing. When we are talking about some areas seeing 2 inches of rain with this...that is a ton of ice to take a bunch down and cause significant power outages and damage to the network.

New NAM pulling snow significantly further east. Per NAM, storm track looks to be further east. Tonight's model runs will be telling of any new trending.

Also the cold air has now entered northern KS and is still spilling south.

Breaking News:
this just in from Channel 4 (c/o MM): "We are on the positive side of the peach fuzz of possible weather events in the next couple of days."

Since this follows right behind the sad saga of the missing Chihuahua in south OKC you know it just has to be rite.

Go ahead with your graphs and radars and whatnots.
Please. Do.

Well we've seen models do a 180 a day out taking a big snow storm away...NAM is really wanting to go colder it seems earlier. It has the entire metro dancing around 32 by tomorrow evening. This reversal though is only on these last two consecutive runs, but they tend to match up the Euro trend really well.

GFS still has us in the mid 30s for the most part, so it isn't clear cut how this is going to break yet.

Having zero snow cover should buy us a few degrees on Saturday right?

Having zero snow cover should buy us a few degrees on Saturday right?

Not for trees or elevated surfaces.

Not for trees or elevated surfaces.

You reckon all of those severely leaning/listing power poles, on the south side of 122nd, between The Hefner Parkway and May, will finally tip over and have to be replaced with Underground Utilities?

Mike Morgan said peach fuzz, lol.

NWS Norman keeps tweeting that confidence is very low in current watch areas and not everyone in watch will see winter precip.

Also posting good information about how this storm's complexity is making the forecast nearly impossible.

I wouldn't be shocked to see pockets of locations with below freezing conditions and then others not that far away be a degree or two warmer. Which makes this almost impossible to do a blanket forecast and get it right.

It is almost a situation of a CYA headline because Guthrie could see icing but then Crescent doesn't see any. We are going to be so close to the freezing point in so many areas this is turning into a no win situation for any forecaster.

00Z NAM = look out OKC. (Possible ice)

I wouldn't be shocked to see pockets of locations with below freezing conditions and then others not that far away be a degree or two warmer. Which makes this almost impossible to do a blanket forecast and get it right.

It is almost a situation of a CYA headline because Guthrie could see icing but then Crescent doesn't see any. We are going to be so close to the freezing point in so many areas this is turning into a no win situation for any forecaster.


OK,enough of this nonsense. Are we getting snow or rain or anything at all? Most likely it just gets cold as a well diggers azz and no rain snow or anything. If it's going to get cold then lets have some snow! Order it up Venture,you have those magical powers so lets see them in action..


Sorry one too many crownncokes

But please keep the ice away. My generator hasn't been started in a couple of years.

00Z NAM = look out OKC. (Possible ice)

You beat me by 2 seconds. LOL

Wow oh wow. How much further south can it drag this? LOL

OK,enough of this nonsense. Are we getting snow or rain or anything at all? Most likely it just gets cold as a well diggers azz and no rain snow or anything. If it's going to get cold then lets have some snow! Order it up Venture,you have those magical powers so lets see them in action..

Sorry one too many crownncokes

But please keep the ice away. My generator hasn't been started in a couple of years.

I'm regretting making that comment on how we've seen models do a 180 at the last minute and change the forecast. I'm holding back on saying that one thing until the new Euro comes out tonight (few hours away).

And what about those major, already leaning in the direction of innocent vehicular traffic, eastbound on 122nd?
Will the Ice Armageddon (possible) cause them to finally topple?
I don't want to be right there when they do.

That might have made more sense if I had put "old, wood, power poles/above ground" in there somewhere.

Geez . . . The Traffic Lawsuit/Insurance Issues involved would be nearly as incalculable as the weather. =)

So the 00Z NAM has OKC metro below freezing until 6AM Saturday, then just above until 9AM and then back below...essentially bobbing around the freezing mark. By Noon should be into the mid 30s until late that evening.

Precip starts south Metro around 4-6PM tomorrow. mostly SE of I-44. Precip < 0.1 through 6PM. All freezing rain/sleet.

Freezing drizzle/sleet, especially southeast of I-44 through Midnight.

Midnight to 3AM Light/Moderate freezing rain/sleet up to a 0.25" in Norman to 0.1" in Edmond.

By 6AM, heaviest rain/sleet mix will be in the area...up to 0.35" east of I-35 (in the metro only, Eastern OK past Shawnee will see heavy rain too) and around or just over a half inch west of I-35. *SHOULD* be above freezing. Hopefully.

Through 9AM we could be back below freezing again around 0.15 to 0.25" of rain/sleet mix metro wide.

By noon precip should be pretty light as the main first wave moves off. Wave 2 gets going by 2-3PM with up to a tenth of an inch of rain/sleet mix.

3PM to 6PM...Rain/Sleet mix continues with up to another 0.25" of liquid.

So an additional comment to the above. Vertical air profile is showing a good layer of freezing temps from 900 mb down to just above the surface through the entire event. So it is very possible that while surface temps could be above freeezing - sleet will be falling that might screw the roads up a bit. Also don't be shocked in heavier showers/storms (yes storms) tomorrow that you could see a downpour of sleet and even hail mixed in.

With that, we might have to be watching how that has an effect on air temps with frozen precip falling and mixing in with liquid...let alone the liquid already being cooled.

Venture pretty much nailed the NAM. I am going to go out on a huge limb (sarcasm) and predict the 00Z GFS will come in warmer as it notoriously underestimates the strength of these shallow cold airmasses.

Thundersleet/Thunder FZRA is a distinct possibility.

I have a headache.

Depending on what we see from the 00Z GFS and the Euro, I would not be surprised to see OUN extend the Winter Storm Watch another row of counties south.

So do I get to take my wife out Saturday night? (takes lid off bottle, pours out a tylenol) Or will greater OKC be an ice rink? (washes down tylenol with ice tea) Or should I pack some suntan lotion and extra hail insurance (gives up on tylenol, goes straight to morphine) And what about an earthquake (to heck with the morphine, go straight to Slim Whitman records and just give up).

I'm hopeful with the Euro run tonight we'll have a clear idea of what is going to happen. Hopeful.

Depending on what we see from the 00Z GFS and the Euro, I would not be surprised to see OUN extend the Winter Storm Watch another row of counties south.

Wouldn't shock me to see that, or at least a winter weather advisory for the next 2 rows of counties.

I'm hopeful with the Euro run tonight we'll have a clear idea of what is going to happen. Hopeful.

Suuuuure you are :) Sometimes, V, I have this sneaking mental picture of you poring through all these maps and runs, sitting in a simulated leather office chair, spinning from one too many cups of coffee, cackling malevolently, saying "okay, how can I REALLY mess with these guys this time?? " :cool:

5514

LOL! Granted I don't wear ties. ;)

And without fail the 00Z GFS is coming in about 5* warmer than the NAM.

I'd be careful using the snowfall output from the EURO. The EURO turns ice accumulations into snow, which would lead to higher snowfall output. That may be one of the few pitfalls of the EURO. Downsize the snowfall output by a few inches (and don't give me any "That's what she said" remarks) :)

And without fail the 00Z GFS is coming in about 5* warmer than the NAM.

LOL naturally. Now watch...12Z or 18Z run tomorrow it'll magically snap into place colder than the others.

And I'm finding out why you don't sign into twitter on your phone. Rick Smith just retweeted me and holy crap.


I'd be careful using the snowfall output from the EURO. The EURO turns ice accumulations into snow, which would lead to higher snowfall output. That may be one of the few pitfalls of the EURO. Downsize the snowfall output by a few inches (and don't give me any "That's what she said" remarks) :)

But but...big numbers are fun! Ooo...that probably wasn't good to say either.

Yeah, I saw Rick MT you and figured your phone was about to blow up.

Aaron Tuttle and Jeff Piotrowski have gone full-on social media hypefesst in regards to an ice storm for OKC/Tulsa tomorrow-sat.

I saw Jeff P ask about the watch areas if they were expanding (Rick said he didn't believe so)...but I am not shocked that either of those are going in ultra hype mode.

Wouldn't shock me to see that, or at least a winter weather advisory for the next 2 rows of counties.

David Payne on TV9 extended his ice line further south, and said he thinks an ice storm warning may have to be issued for north of I-44.

OUN just updated their graphicast for tomorrow, pushing the rain/frz rain threat area further south:

http://www.srh.noaa.gov/images/fxc/oun/graphicast/image_full2.jpg

Seems to be a lot of chatter tonight of people buying into 1 model run that has doom & gloom. While not out of the question... this is one of those events that a 2 degree shift in the freezing line will be huge in who sees what....

Aaron Tuttle Meteorologist (weatherman)
26 minutes ago
Brace yourself for Epic Ice Storm Impact....tonight's hi-res model has brought in even colder temperatures and lower dewpoints during this entire winter storm and much farther south and east than before. That's good news for me because it means my forecast from Monday remains unchanged. It also means you're about to see everyone else change their forecast at the last minute to follow suite. Either that or they'll wait one more run (the morning one or wait to see other models come around to the same solution) before going all out balls to the wall. Lets just say everyone better hope tonight's run is wrong or this will be an epic event roughly along the I-44 corridor.

Freezing drizzle starts around 4am tomorrow morning along the I-44 corridor and should end by mid morning. Light freezing rain will develop a little earlier than planned, so instead of by 6pm, could be as early as 3pm for areas NW of a line from Ft. Smith to Pauls Valley to Lawton. Just rain south of this line. More freezing rain Friday night, heavy at times and changing over to a little sleet by late Saturday afternoon and a burst of snow Saturday evening/night as the upper low moves overhead for C OK. An earlier mix of sleet and snow for NW OK. A little later for NE. SE OK will be just rain for this event and so will N TX. The highest ice accumulations will be up to an inch along/near I-44 which is devastating for trees and power lines and in the major cities of OKC and Tulsa. If temps can stay below 30 during the event then roadways will be impassible. Otherwise bridges and overpasses are the primary concern at 30-32 degrees. Snow amounts likely highest across far W/NW/N/NE OK where as much as 6" may fall in the harder hit areas. Depends on track of upper low and the 700mb low and if it bombs out vertically stacked or not. Maybe a couple inches in OKC/Tulsa. My focus is less on that anyway right now and more on the important ice impact.

So what if I and the evening model are both wrong and the slightly warmer solutions are correct? What would change? The freezing line would shift a bit back to the NW which means the critical 32 degree line would be along/W of I-44 corridor which places the coldest air out of synch with the heaviest precip, so while there will still be ice in NW OK just not as much, say more like a quarter to half inch which is still a dangerous storm and will still cause problems. So either way someone is going to pay come Friday/Saturday. Please share this post and don't everyone run out to the grocery store all at once!!! Remember things could still change a hair. I'll update again tomorrow morning.

Seems to be a lot of chatter tonight of people buying into 1 model run that has doom & gloom. While not out of the question... this is one of those events that a 2 degree shift in the freezing line will be huge in who sees what....

It is a no win forecast. It is almost a CYA situation where you have to advise of the possibilities, probably put out a low confidence winter weather advisory or freezing rain advisory, and let it play out.

Yup. This is one of those events of you are better to bust with cold rain than to bust with ice storm.

The back pedaling has already begun, this is what happens when you call the event as rain and no big deal when the actual event cannot be predicted. Instead of trying to dilute the situation, take the weathercast time to educate your viewers on why this is difficult. This is one thing I have never understood about the local mets, why not use the 10 minutes allotted for weather cast, to educate viewers on why exactly this system is a matter of a handful of degrees away from ruining someones weekend?


Watch tomorrow evening it very well could end up being warmer and the back pedaling was all for nothing.

I think tonight's model runs are blowing the low out too much from the main stream of precip. This is actually giving a false sense of where the snow axis will setup. Right now models push it over panhandle area into SW KS. I think the comma head will be more tightly held with the main stream of rain/freezing rain.

If the main system ejects any further east, it will begin to move the heaviest precip out east and it may actually dry slot SW and C OK.

This is why I fear this entire storm, not only do we have the actual battle of 32F, we have the possibility of a massive dry slot dragging across the state if this thing unwraps and does not remain more of the closed-low types.

Yea I am going to be that guy and triple post.

Cold air update. SW KS already in the 20s and the OK panhandle is at and below freezing. Right now dewpoints behind the front are in the upper 20s. This is significant to us here in C parts of the state because the dewpoint and wet bulb will help us determine if we will fall below freezing. We have mentioned this many times before, but I will reiterate. Falling precip into cold air causes the air to cool further through evaporation. This will most definitely be a now-cast type storm.

In other words, we'll see everyone in the chat room tomorrow. LOL

Meanwhile, the largest weather advisory area in the country is for a flood watch that extends from eastern Oklahoma to northwest New York. It will be interesting to see how serious that develops.