David Payne - "Winter storm update.. New data coming in continues to show Okla. nailed w heavy snow/blizzard. Arrives this Monday! Prepare this weekend!"

Also, remember to PANIC!!!

Gary England referred to this storm as being Life Threating. I was glad to hear him put it like that.

If you are caught out in it and away from a significant heated shelter it can be life threating.



Was he worried about it for northwestern Oklahoma, or for Oklahoma City?

Harper, Woods, Alfalfa, Grant, Kay, Ellis, Woodward, Major, Kingfisher, Logan, Payne and Beckham County under Winter Storm watch now.

So, far NOT Oklahoma County. It includes most of the NW quadrant of Oklahoma.

WINTER STORM WATCH:

Areas affected: Alfalfa; Beckham; Blaine; Custer; Dewey; Ellis; Garfield; Grant; Harper; Kay; Kingfisher; Logan; Major; Noble; Payne; Roger Mills; Wa****a; Woods; Woodward

Instructions: Keep up with the latest weather information...especially if you plan to travel.

Message summary: ...winter storm watch in effect from sunday evening until early tuesday...
* timing: late sunday evening until sunrise tuesday
* main impact: more than a foot of snow is possible in northwest oklahoma. More than four inches of snow is possible north of i-40 and west of i-35.
* other impacts: gusty northwest wind will cause blowing and drifting snow.

Sunny and 60 on Sunday should help with ground temps....Worst thing will be the blowing snow while driving around here unless the storm shifts

12Z NAM Discussion

3PM to 6PM Sun: First chance of precip arrives in the form of storms in SW OK. Instability will permit some of the storms to be strong, perhaps just barely into severe limits. No frozen precip outside of hail.

6PM to 9PM: Storms fire along boundary throughout western OK. Colder air is also wrapping in quickly so anything north of I-40 at this point will be mixing with or changing to snow/graupel/sleet. Some areas could see 0.1 to 0.5" of precip, highest amounts around Woodward down to north of ElK City.

9PM to 12AM Mon: Line of precip marches east to along the I-35 corridor and back to the west. Generally 0.1 amounts here, but higher back into NW OK where amounts could be 0.5 to 0.7" of precip. Looks like still generally a mix bag in NW OK, all rain here.

12AM to 3AM: Line pushes east of I-35, precip ends (for now) west of I-35. Light amounts...0.1 to 0.3" from Bartlesville to Ada. All liquid.

3AM to 6AM: Rain eastern OK, wrap around slowly moving into NW OK. Very light snow there, maybe an inch.

6AM to 9AM: Wrap around snow still in far NW OK, only around an additional inch at this point still.

9AM through rest of Monday... Very light wrap around in NW OK, dry elsewhere.

So with this run, it would eliminate the winter storm threat for much of OK. New GFS will be in in roughly an hour, so we can compare to that. Historically the NAM has been shifting the heavy snow to the NW in each of the last 3 runs. I'm not buying everything yet until we see the other models to the same. Just something to keep in the back of our heads.

Latest update from Norman...

...DANGEROUS WINTER STORM EXPECTED TO IMPACT OKLAHOMA SUNDAY NIGHT
THROUGH TUESDAY MORNING...


A POTENT WINTER STORM SYSTEM WILL MOVE INTO WESTERN OKLAHOMA
SUNDAY NIGHT...AND EXIT THE REGION BY TUESDAY MORNING. RAIN AND
THUNDERSTORMS ARE EXPECTED TO QUICKLY CHANGE TO SNOW ACROSS
NORTHWEST AND WESTERN OKLAHOMA SUNDAY NIGHT AND OVER CENTRAL
SECTIONS OF OKLAHOMA MID TO LATE MONDAY MORNING.


ACCUMULATING SNOW WILL BE LIKELY SUNDAY NIGHT THROUGH TUESDAY
MORNING... WITH THE BEST CHANCES ACROSS NORTHERN AND WESTERN
OKLAHOMA...WHERE 10 TO 12 INCHES OF SNOW WILL BE POSSIBLE. FURTHER
SOUTH...FROM WEST CENTRAL OKLAHOMA THROUGH THE OKLAHOMA CITY
METRO...3 TO 5 INCHES OF SNOW WILL BE POSSIBLE. STRONG WINDS WILL
ALSO CAUSE BLOWING AND DRIFTING OF SNOW...AND NEAR WHITEOUT
CONDITIONS...WHICH WILL REDUCE VISIBILITIES AND MAKE FOR VERY
DANGEROUS TRAVEL CONDITIONS.


SOME QUESTIONS REMAIN ON THE EXACT PATH OF THE STORM SYSTEM AND
ITS HEAVIEST SNOW. FOLLOW THE LATEST INFORMATION AT
WEATHER.GOV/NORMAN.

I wanted to bring in some more information when it comes to the 12Z NAM run which essentially takes this storm north and spares most of Oklahoma. Here is the HPC model discussion regarding this solution...


...UPPER-LEVEL TROUGH/FRONTAL BNDRY INITIALLY OVER THE WESTERN
STATES...
...SURFACE LOW PRESSURE SYSTEM DEVELOPING ACROSS THE SRN PLAINS ON
SUNDAY...


THE NAM SOLUTION LIES WITHIN THE MODEL CONSENSUS THROUGH EARLY
SUNDAY AS THE TROUGH CROSSES THE INTERMOUNTAIN WEST. BY LATE
SUNDAY AS THE SYSTEM BEGINS TO EXIT THE ROCKIES...DIFFERENCES
BEGIN TO EMERGE. THE TROUGH IS FORECAST BY ALL GUIDANCE TO CLOSE
OFF INTO AN UPR-LVL LOW BY SUNDAY AFTERNOON. THE NAM DOES NOT DIG
THE TROUGH AS FAR SOUTH AS IT CLOSES OFF...WHICH RESULTS IN THE
CLOSED UPR-LVL LOW TRACKING A COUPLE HUNDRED MILES FARTHER NORTH
ACROSS THE PLAINS RELATIVE TO OTHER GUIDANCE. THE NAM ALSO SHOWS
THE SURFACE LOW FARTHER NORTH THAN CONSENSUS. IT IS INTERESTING TO
NOTE THAT THE 00Z ECMWF ENSEMBLE MEAN DOES DEPICT A LARGER CLOSED
CONTOUR WHICH ENCLOSES THE CENTER OF THE NAM UPR-LVL LOW. THIS
INDICATES THAT A SUBSTANTIAL NUMBER OF THE ECMWF ENSEMBLE MEMBERS
SHOWED THIS MORE NORTHERN LOW...AND THE SOLUTION CANNOT YET BE
DISCOUNTED.


The main theme with this is that the NAM 12Z is outside of the current consensus of all the models put together. However, a good number of members of the Euro model ensemble are picking up on the more northern option and this solution. So the 12Z NAM isn't completely out to lunch on its own with this. The GFS is running now and that will give us an idea if this is a late trend developing or just something we need to watch.

Norman also mentioned a possible upgrade to blizzard watches for parts of the forecast area.

Norman also mentioned a possible upgrade to blizzard watches for parts of the forecast area.

At this point that is almost a given. Winds will meet the criteria (35mph sustained) over Western OK. Keep in mind Blizzard watches/warnings has little relation to actual snowfall amounts. It is going to come down to wind and visibilities if there is an upgrade. Right now it looks decent to do the upgrade. 12Z GFS discussion incoming...

Given the uncertainty in the models... the thermal profiles being right on the edge regarding precip type... the possibility of a strengthening system bringing in more cold air faster while also perhaps creating a more pronounced warm nose etc... I think that anyone within 100 miles north or south of whatever advisories are issued should stay aware of the situation. Anything could happen. IMO.

12Z GFS Discussion

Comparing this model to the 12Z NAM, they are pretty different. Up until Sunday AM they are with each other and then they diverge. NAM goes north, GFS digs the closed upper low in more and drags it through the body of Oklahoma. This storm really starts to get cranking while over Oklahoma so points to the East are going to see another significant storm it appears, but back to us.


6PM to 9PM Sun: Precip arrives in Western OK. Amounts very light at this time, maybe up to 0.1". Appears to be mainly liquid.

9PM to 12AM Mon: Precip increases a bit in NW OK, some light drizzle might be streaming in from the south into SW OK. Should start to see mixing and possible change over out in the Panhandle and extreme NW OK. Otherwise still mostly liquid. Amounts 0.1 to 0.4".

12AM to 3AM: Precip lightens up a bunch here with light areas of precip roughly I-35 and back west. All under 0.1". At this point all snow NW OK, rain elsewhere.

3AM to 6AM: Precip starts to increase a bit west of a Tulsa to Durant line, and then roughly east of Lawton to Guthrie to Perry line. Amounts around 0.1" in these areas. Another band forming out in the panhandles. Mostly all liquid precip still as temps will be pretty warm.

6AM to 12PM: Precip cranks up during this time block. West 1/3rd is 0.1 to 0.3", Central Third 0.3 to 0.8", Eastern Third 0.1" to 1"...the bullseye is roughly in an area east of Ponca to Norman to Ada, and then West from Ada to Tulsa to Bartlesville. All liquid except for the area north of a line from Frederick to El Reno to Perry to northern Osage County (can't think of a city up there LOL). Some areas out there could see a good 3-5" of snow during the time, 1-3" further South and East you get. Surface winds will be around 25-30 kts over West Central OK which would star to push up against blizzard criteria.

12PM to 6PM: First band is in Eastern OK, lighter precip/dryslotting over Central, and then 2nd band over Western third of OK. 0.1 to 0.4" west, around 0.1" central, and up to 1" east. Everything west of a Miami to Tulsa to Durant line should be snow at this point. Surface winds forecast around 20-25kts, so a bit lighter but still will cause decent blowing/drifting. Snowfall amounts look like less than an inch Central to 3-5" SW, and 6-8" NW by this point.

6PM to 12AM Tue: All snow statewide at this point. Winds generally around 20kts. Precip starts to exit pretty quickly. Dry west, less than 0.1" central, and around 0.1" out east...except far NE OK may still see some heavier precip. Storm total snow amounts by this point don't look much different than stated above. Generall...3-5" SW, 6-8" NW, 3-6" NC, ~1" Central, <1" SC, 0" NE, ~1" SE. Important to note far NE OK is the last to see change over, reducing their chance for accumulating snow.

Keep in mind ground temps in some areas will still be warm and surface temps may not be below freezing during this event, so melting plays in again of course. Another fun one to watch.

Given the uncertainty in the models... the thermal profiles being right on the edge regarding precip type... the possibility of a strengthening system bringing in more cold air faster while also perhaps creating a more pronounced warm nose etc... I think that anyone within 100 miles north or south of whatever advisories are issued should stay aware of the situation. Anything could happen. IMO.

This one is cake when you look at temperature profiles when compared to the last 2 systems. We aren't going to be riding the line nearly as closely as we were the last two systems. Biggest thing right now is going to be the track of the system.

Updated Model Discussion from HPC...

...UPPER-LEVEL TROUGH/FRONTAL BNDRY INITIALLY OVER THE WESTERN
STATES...
...SURFACE LOW PRESSURE SYSTEM DEVELOPING ACROSS THE SRN PLAINS ON
SUNDAY...

PRELIMINARY PREFERENCE: GFS/00Z ECMWF/00Z ECMWF ENSEMBLE MEAN BLEND
CONFIDENCE: BELOW AVERAGE

THE NAM SOLUTION LIES WITHIN THE MODEL CONSENSUS THROUGH EARLY
SUNDAY AS THE TROUGH CROSSES THE INTERMOUNTAIN WEST. BY LATE
SUNDAY AS THE SYSTEM BEGINS TO EXIT THE ROCKIES...DIFFERENCES
BEGIN TO EMERGE. THE TROUGH IS FORECAST BY ALL GUIDANCE TO CLOSE
OFF INTO AN UPR-LVL LOW BY SUNDAY AFTERNOON. THE NAM DOES NOT DIG
THE TROUGH AS FAR SOUTH AS IT CLOSES OFF...WHICH RESULTS IN THE
CLOSED UPR-LVL LOW TRACKING A COUPLE HUNDRED MILES FARTHER NORTH
ACROSS THE PLAINS RELATIVE TO OTHER GUIDANCE. THE NAM ALSO SHOWS
THE SURFACE LOW FARTHER NORTH THAN CONSENSUS. THE GFS SOLUTION
LIES RELATIVELY CLOSE TO THE 00Z ECMWF/00Z UKMET. IT IS
INTERESTING TO NOTE THAT THE 00Z ECMWF ENSEMBLE MEAN DOES DEPICT A
LARGER CLOSED CONTOUR WHICH ENCLOSES THE CENTER OF THE NAM UPR-LVL
LOW. THIS INDICATES THAT A SUBSTANTIAL NUMBER OF THE ECMWF
ENSEMBLE MEMBERS SHOWED THIS MORE NORTHERN LOW...AND THE SOLUTION
CANNOT YET BE DISCOUNTED. AT THIS POINT...WILL RECOMMEND A BLEND
OF THE GFS/00Z ECMWF/00Z ECMWF ENSEMBLE MEAN. THIS REPRESENTS A
CONSENSUS SOLUTION WITH AN ALLOWANCE FOR THE POSSIBILITY OF A
SLIGHTLY FARTHER NORTH SOLUTION IN THE DIRECTION OF THE NAM.

This one is cake when you look at temperature profiles when compared to the last 2 systems. We aren't going to be riding the line nearly as closely as we were the last two systems. Biggest thing right now is going to be the track of the system.

That's good to hear. So you feel pretty good about the model's grasp of when/where the system will close off and intensify? It looks like it may begin to occlude and wrap warm air pretty far around the low. I'm still learning this stuff so feel free to set me straight whenever it's necessary. I'm learning a lot in these weather treads. :-)

Danielle Dozier gives her .02 cents:

Dangerous winter storm sets its eyes on Oklahoma - Oklahoma City - OKC - KOCO.com (http://www.koco.com/weather/Dangerous-winter-storm-sets-its-eyes-on-Oklahoma/-/9845544/19053100/-/70rc3rz/-/index.html)

Little surprise at the end of her article...

That's good to hear. So you feel pretty good about the model's grasp of when/where the system will close off and intensify? It looks like it may begin to occlude and wrap warm air pretty far around the low. I'm still learning this stuff so feel free to set me straight whenever it's necessary. I'm learning a lot in these weather treads. :-)

Honestly I think the models are still lost. LOL What can you do though. 12Z GFS seems to take the surface low south/along Red River. Which is usually good for us. The upper low is pretty much going to go in a straight line from Wichita Falls NE to Fayetteville, AR. I personally would like to see it better stacked with the surface low to give us a better shot at the heavier precip. We'll see how things work out. It is hard to commit to any particular model solution at this point. HPC is pretty much saying the 12Z runs are borderline worthless and sticking with the 00Z runs. I guess it is wait and see when the 18Z run comes out.

This is a tough forecast in terms of track. I have been calling for the closed-off low play since Thursday - and the GFS wants to make it happen. The NAM seems plausible at this point and I could see this dry-slotting OK, save the panhandle.

Tonight we should have a better idea if the NAM is legit or just trying to toss in a wrench. Trends this winter have been NAM shifts south at the last minute and GFS totally nailed the last storm.


As of right now I side with the GFS in terms of track - I still think it is getting a poor handle on temperatures. Ground temperatures will go up with the southerly flow of moist, warm air tomorrow - but we have had very hard freezes the last few days and the ground is chilled with moisture below the surface. I don't see nearly as much melting as the previous two storms mainly due to this reason alone. This storm is also different in that, it basically is a make or break type storm of either getting large accumulation of snow over a small area, or you see little to nothing. The last two storms have been considerably more broad. If this does indeed come out as closed off low, watch out [whoever it tracks over].

@ Venture: Lol! I agree. Whaddaya gonna do? That's interesting though that the latest runs are being pretty much discounted by the HPC... simply because the latest models have better RAOB sampling than the former. They're doing some weird things... like the NAM moving the snow field north while the low tracked a little further south... it's weird. You've been pretty dead on regarding the last couple systems though so I thought I'd ask what you thought. I'm a musician by trade and a weather junkie since I was 4 so... it's fascinating to me. Thanks again sir.

Anon - Pretty much agree with all you are saying. I've been liking how GFS actually has done well with the last couple of systems. I also hate last minute changes in models, but we'll see what happens.

Decious - Yeah you would think the 12Z models would be nailing it since they are getting the upper air data, but who knows. We'll see what 18Z and 00Z show and see if we can establish a trend. I really wouldn't be shocked to see Norman drag the WSW further south a couple more tiers of counties to account for the GFS and more southerly track. After all...it is a watch. :)

http://www.srh.noaa.gov/images/fxc/oun/graphicast/image_full6.jpg

Winter Storm Watch issued for the metro and surrounding areas:

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE NORMAN OK
312 PM CST SAT FEB 23 2013

OKZ023>031-033>036-038-TXZ083-240515-
/O.EXA.KOUN.WS.A.0002.130225T0000Z-130226T1200Z/
CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-CLEVELAND-
POTTAWATOMIE-SEMINOLE-HARMON-GREER-KIOWA-JACKSON-COMANCHE-
HARDEMAN-
INCLUDING THE CITIES OF...ANADARKO...YUKON...EL RENO...MUSTANG...
OKLAHOMA CITY...CHANDLER...CHICKASHA...PURCELL...NORMAN...M OORE...
SHAWNEE...SEMINOLE...HOLLIS...MANGUM...HOBART...AL TUS...LAWTON...
QUANAH...CHILLICOTHE
312 PM CST SAT FEB 23 2013

...WINTER STORM WATCH IN EFFECT MONDAY AND MONDAY NIGHT...

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A WINTER STORM
WATCH...WHICH IS IN EFFECT MONDAY AND MONDAY NIGHT.

* MAIN IMPACT: WIDESPREAD SNOW ACCUMULATIONS OF 4 TO 6 INCHES AND
ISOLATED HIGHER AMOUNTS ARE POSSIBLE ACROSS PORTIONS OF WESTERN
NORTH TEXAS AND SOUTHWEST OKLAHOMA...UP THROUGH CENTRAL PORTIONS
OF OKLAHOMA.

* TIMING: HEAVIEST SNOW FROM WESTERN NORTH TEXAS UP THE I-44
CORRIDOR IS EXPECTED MONDAY AFTERNOON THROUGH MONDAY NIGHT.

* OTHER IMPACTS: STRONG NORTHWEST WIND WILL CAUSE BLOWING AND
DRIFTING SNOW...WHICH WILL SIGNIFICANTLY RESTRICT VISIBILITIES
AND MAKE TRAVEL VERY DANGEROUS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

KEEP UP WITH THE LATEST WEATHER INFORMATION...ESPECIALLY IF YOU
PLAN TO TRAVEL.

Im guessing the NWS is thinking it will go a little bit further south since the last update.

Special Weather Statement from NWS Tulsa:


...A SIGNIFICANT WINTER STORM WILL IMPACT MUCH OF EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS LATE MONDAY INTO EARLY TUESDAY...

AN UPPER LEVEL SYSTEM WILL EJECT OUT OF THE DESERT SOUTHWEST
SUNDAY...AND MOVE EAST NEAR THE RED RIVER AND EVENTUALLY INTO
ARKANSAS MONDAY INTO MONDAY NIGHT. RAIN WILL INCREASE ACROSS MOST OF
THE AREA LATE SUNDAY NIGHT INTO MONDAY...WITH A MIX OR CHANGEOVER TO
SNOW POSSIBLE NORTHWEST OF INTERSTATE 44 BY LATE MONDAY AFTERNOON
OR EARLY EVENING.
ACCUMULATING SNOW WILL BE POSSIBLE ACROSS NORTHEAST OKLAHOMA AND
NORTHWEST ARKANSAS MAINLY MONDAY NIGHT INTO EARLY TUESDAY AS
COLDER AIR WRAPS INTO THE AREA BEHIND THE EXITING UPPER SYSTEM.
STRONG NORTHWESTERLY WINDS DEVELOPING MONDAY NIGHT WILL ALSO
RESULT IN AREAS OF BLOWING SNOW AND REDUCED VISIBILITIES. AT THIS
TIME...UP TO 4 INCHES OF SNOW WITH LOCALLY HIGHER AMOUNTS APPEAR
POSSIBLE MAINLY ACROSS PARTS OF NORTHEAST OKLAHOMA.
PAWNEE...OSAGE AND WASHINGTON COUNTIES IN NORTHEAST OKLAHOMA HAVE
BEEN INCLUDED IN A WINTER STORM WATCH BEGINNING MONDAY AFTERNOON.
THERE REMAINS UNCERTAINTY CONCERNING THE TRACK OF THE SYSTEM
AND RESULTANT SNOWFALL...ALTHOUGH IT IS LIKELY THAT WINTER WEATHER
HEADLINES WILL EVENTUALLY BE EXPANDED FARTHER EAST AND SOUTH WITH
LATER FORECASTS.
STAY TUNED TO THE LATEST FORECASTS AND STATEMENTS FROM THE
NATIONAL WEATHER SERVICE IN TULSA...AS THIS FORECAST WILL CONTINUE
TO BE REFINED AS NEW DATA COMES IN.
Instructions:
Target Area:
Adair
Cherokee
Choctaw
Craig
Creek
Delaware
Haskell
Latimer
Le Flore
Mayes
McIntosh
Muskogee
Nowata
Okfuskee
Okmulgee
Ottawa
Pittsburg
Pushmataha
Rogers
Sequoyah
Tulsa
Wagoner

Mmk...18Z Model discussion...

NAM first

6PM Sun - 9PM: Precip moves in through Western OK. Mostly like 0.1 to 0.2" of precip over most areas. North of I-40 Snow/Sleet/Graupel Mix, South of I-40 rain.

9PM - 12AM Mon: Two areas of light precip, one from SC to SW OK and the other in the OK PH. Mostly the same with precip type, still a mix or rain in most areas. Maybe another 0.1" to 0.2" of precip in spots.

12AM - 3AM: Band weakens some as it moves east, most over much of Western OK west of I-35. Heaviest precip (heavy being relative of 0.1 to 0.2" amounts) in NC OK, mainly less than 0.1" elsewhere. Still looking at mostly rain with a mix here and there.

3AM - 6AM: Scattered light precip across the state. Heaviest amounts in NC OK still from near the OKC area to the North along I-35 and west of 0.1 to 0.3". Lot of warm air still, so mostly all rain still except for far W OK and far N OK.

6AM - 9AM: Change over should start kicking in over NW, NC, and SW OK as cold air works in. Precip amounts look heaviest from Central OK arching north and then northwest. Dry slot pushing through much of SW OK approaching Central areas. Amounts look 0.1 to 0.4"...heavier the further north you get.

9AM - 12PM: Cold air mixes in a bit more. Elk City to Clinton to Enid to Ponca should be all snow at this point. SW OK a mix (where precip falls). Central mix to mostly rain. Heaviest precip pretty much just in the Northern half of OK which areas around OKC and back to the SW dryslotted.

For nearly the rest of the day is going to be a carbon copy of what I posted above, going by the NAM so I'm going to stop here. NAM really doesn't show much change over in OKC until 9PM, and at that point majority of the precip is already moving away.


GFS next...
Not going to get into a long discussion here. Not really all that different than previous runs. It increase snowfall in NW OK, decreases it pretty much everywhere else. A lot of this is coming down to timing of cold air and the precip. For us it keeps showing precip starts to wind down once it gets cold enough to ensure 100% snow. Surface temps never really get below freezing, so icing isn't a major concern.

Neither of these models are really the favorites right now, and their run to run consistency hasn't been established yet. Pretty much sticking with my earlier thinking with Norman seems to be as well when it comes to their advisories.

I'll double back tonight when the next runs come out to really go over things.

Norman's AFD...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
327 PM CST SAT FEB 23 2013


.DISCUSSION...
STRONG WINTER STORM WILL IMPACT THE REGION LATE SUNDAY THROUGH
LATE MONDAY NIGHT. FORECAST WILL BE TAILORED TO A GFS/ECM BLEND
WITH THE WRF/NAM DISREGARDED. ALTHOUGH THERE ARE SOME SLIGHT
VARIATIONS WITH RUN TO RUN CONSISTENCY OF GFS/ECM...THE WRF/NAM
HAS BEEN SIGNIFICANT OUTLIER. TRENDED SNOW TOTALS FARTHER SOUTH
AND EAST WHICH WILL ALLOW US TO EXPAND THE WINTER STORM WATCH
THROUGH THE OKC AND LAW AREAS. CONFIDENCE IS NOT ALL THAT HIGH ON
SNOW TOTALS FOR THE I-44 CORRIDOR AS SNOW WILL INITIALLY BE IN
WARM LOWER LEVEL ENVIRONMENT...SIMILAR TO THE PAST FEW EVENTS.
BEST ACCUMULATIONS WILL BE WHERE WE CAN GET CONVECTIVE/ENHANCED
BANDING NORTH AND WEST OF MID-LEVEL CYCLONE...WHICH TRENDS SUGGEST
COULD BE NEAR THE I-44 CORRIDOR. OF GREATEST IMPACT MAY BE THE
POTENTIAL FOR BLIZZARD- LIKE CONDITIONS WITH STRONG WINDS MONDAY
AND MONDAY NIGHT. FAIRLY HIGH PROBABILITY THAT A BLIZZARD WARNING
WILL BE NEEDED OVER AT LEAST WESTERN AND NORTHERN PORTIONS OF
OKLAHOMA...PERHAPS INTO CENTRAL OKLAHOMA. WE DECIDED TO LEAVE
CURRENT WINTER STORM WATCH GOING AND TRANSITION TO WINTER STORM
AND/OR BLIZZARD WARNINGS AS OPPOSED TO GOING WINTER STORM
WARNING...WHICH ALREADY MENTIONS THE POSSIBILITY OF BLIZZARD
CONDITIONS...TO BLIZZARD WATCH...THEN THE WARNINGS.


FOR THE MOST PART...KEPT FORECAST TRANQUIL AFTER EXIT OF THIS
STORM SYSTEM AND IT LOOKS BELOW AVERAGE FOR TEMPS INTO NEXT
WEEKEND WITH REINFORCING COLD FRONTS INDUCED BY EASTERN LONG-WAVE
TROF DEVELOPMENT.

Are the ground temps in the 40's already and set to go up even more with tomorrow's weather?...I'm wondering if we are looking at a mostly grass impact aside from the blowing snow

Assuming the bullseye doesn't shift south of course

Are the ground temps in the 40's already and set to go up even more with tomorrow's weather?...I'm wondering if we are looking at a mostly grass impact aside from the blowing snow

Assuming the bullseye doesn't shift south of course

Mesonet has us at 42-45 over much of the metro area. It'll cause some initial melting yes, but it doesn't take much to cool those down. Even with a foot of snow on the ground, temps in NW OK are still in the mid to upper 30s.

So new NAM just keeps with the same. Heavy rain/storms through early Monday and then dry slots us. Some wrap around overnight Tuesday with some light snow.

HPC seems to be tossing the last few NAM runs out still, preferring GFS/ECMWF for this. New GFS will be out later this evening.

As we all wait for the new update, NWS Norman has put out these graphics...

http://www.srh.noaa.gov/images/fxc/oun/graphicast/image4.jpg

6AM Monday - 6PM Monday: This graphic isn't loading the small size, but can be seen here: http://www.srh.noaa.gov/images/fxc/oun/graphicast/image_full1.jpg

http://www.srh.noaa.gov/images/fxc/oun/graphicast/image3.jpg

National Weather Service Text Product Display (http://forecast.weather.gov/product.php?site=OUN&issuedby=OUN&product=AFD&format=CI&version=1&glossary=1)
NATIONAL WEATHER SERVICE NORMAN OK
947 PM CST SAT FEB 23 2013

...DANGEROUS WINTER STORM WILL AFFECT THE AREA SUNDAY NIGHT
THROUGH MONDAY NIGHT...

.UPDATE...
WILL INCREASE LOWS TONIGHT A FEW DEGREES ACROSS PARTS
OF WESTERN AND NORTHERN OKLAHOMA.

WINTER STORM WATCH IS IN GREAT SHAPE.

&&

.DISCUSSION...
CLEAR AND QUIET WEATHER WILL PREVAIL TONIGHT. A MAJOR
WINTER STORM WILL AFFECT THE AREA SUNDAY NIGHT THROUGH
MONDAY NIGHT.

WILL INCREASE LOWS NEAR THE ALTUS...CLINTON...WOODWARD...
AND STILLWATER AREAS TONIGHT AS INCREASING LOW LEVEL WINDS
SHOULD KEEP TEMPERATURES FROM FALLING AS MUCH AS PREVIOUSLY
FORECAST.

THERE IS A LOW CHANCE FOR PATCHY LIGHT FOG OR FREEZING
FOG LATE TONIGHT INTO SUNDAY MORNING WITH THE BEST CHANCES
OVER THE SNOWPACK IN FAR NORTHERN OKLAHOMA...BUT WILL
NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
VISIBILITIES SHOULD MAINLY STAY ABOVE 3 MILES IF THE
FOG DEVELOPS.

WINTER STORM WATCH IS IN GOOD SHAPE. BLIZZARD CONDITIONS
ARE LIKELY ACROSS NORTHWEST OKLAHOMA MONDAY AND MONDAY
NIGHT. WILL ALLOW 00Z MODEL RUNS TO COME IN AND DEFER TO
THE MIDNIGHT SHIFT FOR ANY POSSIBLE UPGRADE TO WARNINGS.
ROUTINE FORECAST PRODUCTS WILL UPDATED SHORTLY.

The GFS and NAM are in near perfect agreement over the track. As it looks now it seems as though Tulsa will be left out on the snow part of the storm, but OKC will be riding the line a little closer. Tight snow gradient with this storm.

Wherever this storm tracks the people beneath it will get dumped on.

The Wichita NWS has 5-10" predicted for the Tulsa metro and north of the OKC metro. I don't really see that happening but I wouldn't complain if it did...

Finally got a chance to look at the models tonight.


First off... Wow this storm is great to see. Two large systems back to back like this is a great sign for a lot the plains.

Now onto the track - some better agreement coming together, NW OK is obvious to get pounded. I am starting to think OKC could get dry-slotted at this point. I know the NAM is going to shift SE [please!], it has every storm. But for some reason, I can see this epic opportunity of getting snow being a huge bust for OKC. I really want to be wrong, but just going off the current runs. I won't hold my breath.

I still like the GFS as it did a great job with the similar setup last week, but it needs to stay as a closed-off low and really anchor down S of the Red River, that will crank out ungodly amounts of snow over 2/3 of the state. Kansas had their fun last week, it is our turn.


Will chime in with more serious posts after tomorrow morning's runs. Everyone think SNOW!

Finally got a chance to look at the models tonight.


First off... Wow this storm is great to see. Two large systems back to back like this is a great sign for a lot the plains.

Now onto the track - some better agreement coming together, NW OK is obvious to get pounded. I am starting to think OKC could get dry-slotted at this point. I know the NAM is going to shift SE [please!], it has every storm. But for some reason, I can see this epic opportunity of getting snow being a huge bust for OKC. I really want to be wrong, but just going off the current runs. I won't hold my breath.

I still like the GFS as it did a great job with the similar setup last week, but it needs to stay as a closed-off low and really anchor down S of the Red River, that will crank out ungodly amounts of snow over 2/3 of the state. Kansas had their fun last week, it is our turn.


Will chime in with more serious posts after tomorrow morning's runs. Everyone think SNOW!

One of the meteorologists that I follow on twitter (who has been very accurate lately) said that he thinks the models are underestimating the strength of the storm and believes more snow will fall in eastern Oklahoma than the models have forecasted. Not sure how that would play out for you all, though.

WINTER STORM WARNING OUT FOR OKLAHOMA CITY

Updated: Sun Feb-24-13 01:36am CST
Effective: Sun Feb-24-13 01:36am CST
Expires: Tue Feb-26-13 06:00am CST

Severity: Moderate
Urgency: Expected
Certainty: Likely

Status: Actual
Type: Alert
Category: Met

Areas affected: Canadian; Cleveland; Comanche; Garfield; Grady; Grant; Kay; Kingfisher; Lincoln; Logan; McClain; Noble; Oklahoma; Payne; Pottawatomie; Seminole

Instructions: Avoid travel. Be sure you can take care of yourself and your family if you lose electrical power. Monitor weather forecasts and information.

Message summary: ...blizzard conditions likely monday and monday night across parts of western and northern oklahoma...
...winter storm warning in effect from midnight monday to 6 am cst tuesday...

The national weather service in norman has issued a winter storm warning for snow and blowing snow...which is in effect from midnight monday to 6 am cst tuesday. The winter storm watch is no longer in effect.

* timing: snow will begin in the oklahoma city and lawton areas monday morning and be heavier monday evening. The snow will end west to east early tuesday.
* other impacts: strong and gusty northwest wind will cause blowing and drifting snow. At times near blizzard conditions will be possible. Travel will be very dangerous monday until at least tuesday morning.

Meanwhile, there is a blizzard warning out for most of the western 1/3 of Oklahoma:


BLIZZARD WARNING ALERT


...BLIZZARD CONDITIONS LIKELY MONDAY AND MONDAY NIGHT ACROSS
PARTS OF WESTERN AND NORTHERN OKLAHOMA...

...BLIZZARD WARNING IN EFFECT FROM 6 PM THIS EVENING TO 6 AM CST
TUESDAY...

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A BLIZZARD
WARNING...WHICH IS IN EFFECT FROM 6 PM THIS EVENING TO 6 AM CST
TUESDAY. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

* TIMING: SNOW...HEAVY AT TIMES...IS EXPECTED TO BEGIN OVER
WESTERN OKLAHOMA SUNDAY EVENING AND INTENSIFY AND PROGRESS EAST
DURING MONDAY. THE SNOW WILL END WEST TO EAST EARLY TUESDAY.

* OTHER IMPACTS: STRONG NORTHWEST WIND WILL CAUSE BLIZZARD
CONDITIONS ACROSS PARTS OF WESTERN AND NORTHERN OKLAHOMA MONDAY
AND MONDAY NIGHT WITH NEAR ZERO VISIBILITY AND CONSIDERABLE
BLOWING AND DRIFTING SNOW. TRAVEL WILL BE VERY DANGEROUS MONDAY
AND TUESDAY MORNING.

Instructions: DO NOT TRAVEL! STAY INSIDE! STRONG WINDS AND BLINDING SNOW WILL MAKE TRAVEL NEARLY IMPOSSIBLE. THIS IS A LIFE THREATENING STORM.
Target Area:
Alfalfa
Beckham
Blaine
Caddo
Custer
Dewey
Ellis
Greer
Harmon
Harper
Jackson
Kiowa
Major
Roger Mills
Was hita
Woods
Woodward

Venture its looking like most believe this thing will affect OKC midday tomorrow. Are we talking a normal if soggy morning, but nightmare drive Home? Thinking about how the schools might be handling this...normal AM, poss blizzard late day but before school lets out? Sure looks like timing is a headache!

In all honesty this morning, I am really torn on what is going to happen with this one. So the preference right now by HPC is a mix of the 00Z GFS and 00Z UKMET, but I will say the 06Z NAM and GFS line up pretty well now and continue the trends. Also considering the success the GFS has been having lately, that helps with confidence.

6PM Sunday - 12 AM Monday
GFS: Precip moves in through western 1/3 of state. Line of storms from SW OK into TX. There is a Slight Risk of severe weather for this area today marked by SPC. Amounts roughly 0.1 to 0.4 (highest in Woods County).
NAM: Precip layout identical to the GFS for the most part, but a little lighter in amounts. It keeps the heaviest precip back in the panhandles at this point so around 0.1" for NW OK only.

12 AM Monday - 6 AM
UKMET: Significant precip is over the Western 1/3rd to 1/2 of the state with precip amounts of 0.5 to 0.75", with slightly higher amounts around Lawton to Frederick of 0.75 to 1.0".
GFS: Pretty good alignment with UK. Low is SW of Wichita Falls at this point with heaviest precip band from Elk City up to Ponca of amounts 0.4 to 0.75". Elsewhere 0.1 to 0.4" from just west of a Tulsa to McAlester line.
NAM: Solid line of heavy precip from I-35 to the west. up to 1-1.5" north of I-40 and up to 0.8" south of I-40. Surface low matched up with others.

6 AM to 12 PM
UKMET: Low tracks south of Red near Gainsville TX. Heaviest precip will be over the main body of the state at this point. Upper air temps would suggestion all snow roughly from the I-44 area back to the west.
GFS: Low is right along the Red River just west of Marietta. Significant precip is generally north of I-40 with two main areas. NW OK over 1 to 1.5" and NE OK near TUL of around 1". Otherwise generally 0.5 to 0.8". SW quarter of OK south of I-40 and west of I-35 is dryslotted at this point.
NAM: Surface over Frederick, so west of the other guidance by a bit. Heavy band of precip from Seminole to Lake Eufaula up to TUL and west. Amounts up to 1" in these areas. Up to 0.75" south of this area. Lighter in NE and SE OK.

12 PM to 6 AM
UKMET: Surface low tracks along the Red River into extreme SE OK. Heaviest wrap around is back through Central and Eastern OK. Western 1/3rd will see another 0.1 to 0.4", Central 0.4 to 0.75", and Eastern 0.4 to 0.75" as well.
GFS: Heaviest precip is now over NE OK of 1 to 1.5". Still moderate to heavy precip in NC and NW OK of 0.5 to 0.8". Lighter elsewhere. Dryslot appears to try to fill in some, but precip only gets up to 0.1".
NAM: Low is over just past Durant at this point. SC OK is the only one dry slotted at this point. From Altua to Norman to McAlester looks like at least 0.5 to 0.75" of precip, then around 1 to 1.5" north of I-40 with highest targets near TUL and NW OK.

6PM to 12 AM
GFS: Much of the precip is out of SW OK. Looks like everyone is dryslotted except for parts of NW and NC OK where 0.1 to 0.4" could fall, and SE OK where around 0.1" could fall.
NAM: Dryslot says hello and shuts down most of Eastern OK from TUL and south. Wrap around just near I-35 and west. < 0.2" south of I-40, up to 0.5" north of I-40...around 0.4" NW OKC to 0.1" in Norman. Low is out over NC AR.

12 AM Tuesday to 6 AM
UKMET: Surface low is all the way to STL at this time. Wrap around continues over much of the state. 0.1" or less West, 0.1 to 0.4" over Central, and 0.1 to 1" over Eastern (higher NE, lowest SE).
GFS: Most of the state is dry but may have some lingering flurries will be around.
NAM: Some wrap around still from OKC back to the NE, but only around 0.1" more precip if that. Low up near SC MO.

So general thoughts with all this is that the models are decently well aligned. NAM is a bit slower. UKMET is wetter. GFS is kinda in the middle and the one that pushes the dryslot the most. Upper air temps come into play for us then. GFS keeps it above freezing up through almost 2000' until Monday evening. NAM is above freezing to that level up until Noon Monday. So it becomes a battle of who is right. At this point my thinking is that we'll get a good bit of rain through the first part of Monday, but as precip falls it will continue to cool the air column overhead and get us over to snow. This trick is doing it before we get dryslotted. I would love to say we won't, but experience down here shows it happens nearly every time. It also seems once the dryslot works in, the wrap around usually fails to fill in and replace it.

So while I think the advisories are done pretty well with this one, the time when we change over is going to be key in this. Also if we get dryslotted too early that will be all she wrote. Now if this goes to snow sooner than expected, and UKMET is right, then looks like we are all going to get a day or two off work this week simply because no one can get through that much snow. LOL

Accuweather has it rain thru mid-day turning to snow with little to no accumulation...Then snow in the evening with a total accumulation of 1-3...I like that one

The Weather Channel seems to be using the same model as their graphic shows green for rain in OKC at 5:00 PM tomorrow

Accuweather has it rain thru mid-day turning to snow with little to no accumulation...Then snow in the evening with a total accumulation of 1-3...I like that one

The Weather Channel seems to be using the same model as their graphic shows green for rain in OKC at 5:00 PM tomorrow

I won't send the lynch mob after you for even visiting those sites. :-P

Venture, I apologize for asking you to repeat something I am sure you've said before, but when you use the term dryslot/dryslotted, what happens/what does that mean? Do the temps fall and turn things to ice or is it just dry, or what? We hear the term "dryline" in spring patterns but I don't read this as being related to that. Sorry to be dense.

Venture, I apologize for asking you to repeat something I am sure you've said before, but when you use the term dryslot/dryslotted, what happens/what does that mean? Do the temps fall and turn things to ice or is it just dry, or what? We hear the term "dryline" in spring patterns but I don't read this as being related to that. Sorry to be dense.

Dry slot is simply an area of dry air that gets pulled into the system, usually from the Southwest, and cuts off precip mostly. In winter storms this tends to end the accumulating precip but can lead to freezing drizzle in many cases.

KFOR has the rain change to snow around 3:00 PM for OKC

Thanks to Venture and the others for once again giving us the best info possible without all the hype of the news stations. I'm going to gas up the jeep today in hopes of a bunch of snow :)

Mike Collier, the meteorologist I referred to last night, is predicting 2-6" for the Tulsa area tomorrow evening through Tuesday morning.

Thanks to Venture and the others for once again giving us the best info possible without all the hype of the news stations. I'm going to gas up the jeep today in hopes of a bunch of snow :)

The hype is why I also like to look at the national sites since they aren't necessarily pushing for ratings...But I do pay way more attention to our weather advisors on here

Looks like Norman is preparing to revise snowfall amounts downward...Yay

NOAA
weather.gov
National Weather Service National Headquarters

Area Forecast Discussion
Issued by NWS Oklahoma City, OK


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
1052 AM CST SUN FEB 24 2013

.UPDATE...
NO SIGNIFICANT CHANGES TO GOING FORECAST THIS MORNING. 12Z MODEL
SUITE INDICATING WINTER STORM ON TRACK WITH PREVIOUS RUNS. VERY
HIGH MODEL DERIVED SNOW TOTALS OVER NORTHWEST OKLAHOMA...STILL
APPEAR TO BE OVERDONE...AS WELL AS SOME OF THE SOUTH/SOUTHEAST
FRINGE AMOUNTS WHERE SIGNIFICANT MELTING ISSUES WILL TAKE AWAY
FROM ACCUM POTENTIAL. WILL LIKELY TWEAK SNOW AMOUNT FORECAST FOR
AFTERNOON PACKAGE BUT DO NOT EXPECT MUCH CHANGE /IF ANY/ TO
HEADLINES. IN ADDITION TO WARNINGS THAT WE HAVE GOING... THERE
WILL LIKELY BE WIND ADVISORY AND/OR WINTER WEATHER ADVISORIES
FARTHER SOUTH AND EAST LATE TOMORROW AND TOMORROW NIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 56 36 36 30 / 10 80 90 60
HOBART OK 56 33 36 25 / 10 70 80 30
WICHITA FALLS TX 67 38 39 31 / 10 60 60 30
GAGE OK 47 26 32 23 / 30 100 90 20
PONCA CITY OK 48 34 35 29 / 10 90 90 70
DURANT OK 65 41 48 32 / 10 50 70 40

Don't read much into that for nw ok, they haven't gone with some of the crazy high numbers up there. Models for around here have never gone above an inch or two, so they are probably going to pull back on the numbers they came up with since model guidance never caught on.

Don't read much into that for nw ok, they haven't gone with some of the crazy high numbers up there. Models for around here have never gone above an inch or two, so they are probably going to pull back on the numbers they came up with since model guidance never caught on.

Translation: No work/school cancelling snow event, bidness as usual?

Translation: No work/school cancelling snow event, bidness as usual?

well crap.... I want snow and lots of it

well crap.... I want snow and lots of it

It was a question for V, I'm not quite ready to call it off just yet, just starting to get that old familiar feeling.

Here we go, moisture is here. Snowing in CO now.

Models are in really good agreement, I can see why all the forecasts are pretty similar right now.

Keep in mind, any slight shifting south in the track, basically turns OKC from a trace to no accumulation, to upwards of 8+. This is yet again another tedious forecast for C OK. My gut wants to say OKC gets dry-slotted when it comes to the snow, and we see cold rain and some wet snow showers - but part of me is banking on a last minute shifting south. I have noticed with the last couple of systems, the models run the storm NNE too soon. The low anchors down and turns almost due east for a little longer as it ejects. If this type of scenario happens, it moves OKC and even Tulsa into the mix.

I still think the system is calling for too warm of temperatures, the strong NNW winds coming through with the intense wrap around is going to be bringing frigid air directly off of an existing snowpack. I have a feeling some of this air will infiltrate into the system earlier than anticipated. However, this does not exclude the possibility of the dry slot eroding a massive precip. hole directly over SW,S, and C OK.

I agree Anonymous. I could see the storm shifting but I just have a feeling (nothing scientific) that it won't.

I also have a feeling that nothing much will happen in Central OK. It seems like every time they try to warn us in advance, nothing happens. Then when they give the "all clear", we get a bunch of snow.

I still did a grocery run yesterday just in case. :P

well crap.... I want snow and lots of it

My daughter and her family can help you find a place in Cheyenne WY. They tend to get way more than she would prefer.

I also have a feeling that nothing much will happen in Central OK. It seems like every time they try to warn us in advance, nothing happens. Then when they give the "all clear", we get a bunch of snow.

I still did a grocery run yesterday just in case. :P

Already highs are around 5 degrees higher than forecasted. It will be interesting to see if that works out for more rain and less snow.

Looking at the rapid refresh models..it seems to be digging the storm in over nw texas and doesn't move it much. This would be further south than the nam has been showing and somewhat close to gfs.

Starting to get cloudy in Amarillo.

Looking at the rapid refresh models..it seems to be digging the storm in over nw texas and doesn't move it much. This would be further south thahe nam has been showing and somewhat close to gfs.

Now , if I'm following things correctly, a slower, more southerly
route bodes *worse* for OKC (more snow), right?