January '10 Weather Discussion

[OKCMallen]

I trust Venture more than those guys anywya.

[venture]

Text of the warning, will toss out my thoughts here in a few.

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE NORMAN OK
350 AM CST WED JAN 27 2010

OKZ004>031-033>038-TXZ083>085-272200-
/O.UPG.KOUN.WS.A.0001.100128T1200Z-100129T1200Z/
/O.NEW.KOUN.WS.W.0001.100128T1200Z-100129T1200Z/
HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-
NOBLE-ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-
BECKHAM-WA****A-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-
CLEVELAND-POTTAWATOMIE-SEMINOLE-HARMON-GREER-KIOWA-JACKSON-
TILLMAN-COMANCHE-HARDEMAN-FOARD-WILBARGER-
INCLUDING THE CITIES OF...BUFFALO...ALVA...CHEROKEE...MEDFORD...
PONCA CITY...ARNETT...WOODWARD...FAIRVIEW...ENID...PERRY ...
CHEYENNE...TALOGA...WEATHERFORD...CLINTON...WATONG A...
KINGFISHER...GUTHRIE...STILLWATER...ELK CITY...SAYRE...CORDELL...
ANADARKO...YUKON...EL RENO...MUSTANG...OKLAHOMA CITY...CHANDLER...
CHICKASHA...PURCELL...NORMAN...MOORE...SHAWNEE...S EMINOLE...
HOLLIS...MANGUM...HOBART...ALTUS...FREDERICK...LAW TON...QUANAH...
CHILLICOTHE...CROWELL...VERNON
350 AM CST WED JAN 27 2010

...WINTER STORM WARNING IN EFFECT FROM 6 AM THURSDAY TO 6 AM CST
FRIDAY...

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A WINTER STORM
WARNING FOR ICE... SLEET... AND SNOW... WHICH IS IN EFFECT FROM 6
AM THURSDAY TO 6 AM CST FRIDAY.

* TIMING: THE MOST LIKELY TIME FOR HAZARDOUS WINTER WEATHER WILL
BE FROM EARLY THURSDAY MORNING THROUGH EARLY FRIDAY MORNING.

* MAIN IMPACTS: FREEZING RAIN WILL BEGIN TO ACCUMULATE ON POWER
LINES AND ELEVATED SURFACES DURING THE DAY THURSDAY. THE MOST
LIKELY AREA FOR SIGNIFICANT ICE ACCUMULATION IS SOUTH OF
STILLWATER... EL RENO...HOBART...ALTUS...AND QUANAH WHERE 1/4 TO
1/2 INCH OF ICE ACCUMULATION IS LIKELY. SLEET AND SNOW WILL ALSO
OCCUR. FARTHER NORTH... GREATER SLEET AND SNOW ACCUMULATION ARE
LIKELY FROM WEST CENTRAL TO NORTH CENTRAL OKLAHOMA WHERE 6 TO
12 INCHES OF SNOW IS EXPECTED.

* OTHER IMPACTS: GUSTY NORTH AND NORTHEAST WINDS OF 25 TO 30 MPH
WILL ADD ADDITIONAL STRESS TO POWER LINES THAT MAY HAVE ICE
ACCUMULATIONS. BLOWING AND DRIFTING OF SNOW WILL ALSO BE
POSSIBLE.

* PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING MEANS SIGNIFICANT AMOUNTS OF SNOW...
SLEET...AND ICE ARE EXPECTED. STRONG WINDS ARE ALSO POSSIBLE.
THIS WILL MAKE TRAVEL VERY HAZARDOUS OR IMPOSSIBLE.

[Thunder]

Okay, guys, you know the drill. PANIC! Go str8 to Crest (the small one) and I'll service you! Just ask for Jesse. :-)

[oknacreous]

The 12Z NAM model came in warmer and with a stronger dry slot. Too early to say if this is an important trend (we'll know more late this afternoon). But if so, the band of significant freezing rain would be farther north, more along a Hobart-Norman-Shawnee line and the heavier snow band would be well NW of the OKC metro area with no more than 1 or 2" in OKC but still a lot of sleet. More later.

[venture]

In the same note, I'm struggling with how to really forecast how this will work. Norman surface temps are expected to be around 32-33 during the event as well now. So there is that possibility of limiting ice accumulation.

[kevinpate]

.... Norman surface temps are expected to be around 32-33 during the event as well now. So there is that possibility of limiting ice accumulation.

Hope springs eternal on my end. I have things I'd like to get done if doing so safely is possible.

[venture]

GFS is backing up NAM so far...so yeah. If you were hoping for snow, doesn't look like its going to happen this time around. Looks like change over to sleet won't occur on the far NW side of the Metro until about 9PM-ish Thursday.

Quick note: The live blog chat requires everyone to be moderated until I approve them. I'm trying to get people approved for unmoderated chat once they post something. The chat will remain up through Friday at this point. Link: http://www.anvilcrawlers.com/livechat.html

[FritterGirl]

GFS is backing up NAM so far...so yeah. If you were hoping for snow, doesn't look like its going to happen this time around. Looks like change over to sleet won't occur on the far NW side of the Metro until about 9PM-ish Thursday.

OK - so are we saying more ice and sleet?

If that's the case, for those of us who may be in need of cancelling Thursday events, would this still be advisable, or do you think this is one of those things that will just peter out? All talk, no action?

[venture]

The storm is still going to happen. This will be more ice and sleet - in other words, this is probably the worst solution. Heavy snow is always going to be better than ice. GFS right now is really siding with, as far as the metro goes, don't expect any snow accumulation south of I-40.

[Thunder]

Are you saying the dry slot only affect the snow portion? This doesn't make sense. We had a dry slot that appeared for the last blizzard and it didn't really affect the storm's potential. We saw what happened. I'll just pretend the dry slot isn't there this time and hope we get lots of snow.

So... Uhh... Venture, how advance is the dry slot turning out to be? If it is that much, then we shouldn't expect much from all 3; ice, sleet, and snow.

[westsidesooner]

I trust Venture more than those guys anywya.

Ditto dat!!

[venture]

Okay this is the new best guess for how this will work out. GFS is coming in much dried than NAM and is ending precip pretty quickly early Friday. NAM maintains some wrap around that could drop 1-2" of snow in most of Central OK. This is a blend of the two, but drying things out on the schedule of the GFS with not much if any snow accumulation for OKC. The Ice forecast (first one) is a bit tricky due to warm up working into places, but not in others. Central OK...at least the majority of the Metro area, does appear that this will be primarily an ice event with some some sleet at the end.

[Thunder]

WOW! We really need to get rid of the dry slot.

[rod4soonrs]

no, we need the dry slot to cut down on the freezing rain.

[westsidesooner]

Thanks for going to the jpg format V.

[Thunder]

Okay, I don't understand this. I'm still waiting for Venture to answer this. The dry slot is there, it is making the storm have less snow potential, so shouldn't it affect the ice potential? Moisture is moisture, doesn't matter what form, the dry slot choke the storm. How can the snow go way down while the ice stay way high?

And the models is saying some sort of warmer air aloft, longer time to cool down up there, but the storm is slowing down, so that would give that warmer air aloft to cool down while the storm come crawling in. Right? I'm missing something here. :-(

And how can the models now say the storm will get out of here earlier than predicted previously when the storm is slowing down the movement?

[venture]

Okay, I don't understand this. I'm still waiting for Venture to answer this. The dry slot is there, it is making the storm have less snow potential, so shouldn't it affect the ice potential? Moisture is moisture, doesn't matter what form, the dry slot choke the storm. How can the snow go way down while the ice stay way high?

Dry slot just impacts moisture in the storm. The snow is way down because more warm air is being pulled up into the storm at the mid levels.

And the models is saying some sort of warmer air aloft, longer time to cool down up there, but the storm is slowing down, so that would give that warmer air aloft to cool down while the storm come crawling in. Right? I'm missing something here. :-(

And how can the models now say the storm will get out of here earlier than predicted previously when the storm is slowing down the movement?

This is the first model run to where weather balloons have actually be able to go into the storm and get readings. So you are seeing adjustments in the models based on what is actually going on upstairs. The warmer air aloft is being pulled in by the upper level storm system, so there really isn't any cooling to take place. It is pulling in the air that is over Texas/LA right now.

So to summarize. The dry slot is coming in from the SW and will cut off the precip pretty quickly in the morning on Friday. The colder air aloft will not work in until very late Thursday or early Friday. Timing just isn't right with this one for a major snow event. Classic Oklahoma ice storm.

[Bunty]

Okay, guys, you know the drill. PANIC! Go str8 to Crest (the small one) and I'll service you! Just ask for Jesse. :-)

Congratulations go to you with that fine attitude. Lesser people than you would be bitching about what days like this are gonna mean at work.

[Thunder]

Congratulations go to you with that fine attitude. Lesser people than you would be bitching about what days like this are gonna mean at work.

You need to rephrase that to be more readable.

[Bunty]

Anyway, it's just before noon and already the temperatures as they go over 60 are at or just over predicted highs. I hope that's a good sign for less snow and ice, but I'm not counting on it.

[Bunty]

You need to rephrase that to be more readable.

Sorry, but it's just a sincere compliment. If I were your boss I'd be very happy with ya.

[westsidesooner]

Tulsa weather service is going with much more ice.

DSP ICE Hazard

http://www.srh.noaa.gov/images/rtima...rmIceAccum.png

http://www.srh.noaa.gov/images/rtima...adIce24hr2.png

[MadMonk]

What's the over/under on snow accumulation at Will Rogers?

[Bunty]

Meanwhile, as excitement over the prospect for a lot of frozen precipt. builds, has anyone heard that the NWS has raised the criteria on size of hail to define a severe thunderstorm? It's now at 1" raised from 3/4 in. Story at: National Weather Service - Warning Decision Training Branch

[venture]

What's the over/under on snow accumulation at Will Rogers?

This is an ice storm through and through now, snow accumulation is going to be a minor blessing to give some traction.