OK / AR / KS / MO Winter 2013-2014

[JoMo]

While the details are obviously somewhat different between the major models, the consistency in the main players is pretty impressive so far out. Just for fun... since it is still so far out... here are some of Tulsa's maps to enjoy.

 

 

 

 

Here's the Tulsa snow/ice maps.

[Spot]

Well I think that Frz rain looks to be likely along the I-40 area in OK and parts of NWA at the start before going to a mix of sleet also...but it could be sleet at the onset just going to depend on the depth of the cold air. Mostly all snow in SO MO.

[ouamber]

So pretty much I-44 75-100 miles on either side of it...you should make out with some pretty good snows.  I'm ok with being in the 5 inch range on the south side of Tulsa.  Something tells me these totals are very conservative.  I think the cold air will firmly be in place so the sleet totals go down and therefore more on the snow side, but who knows.  Glad to just be right smack in the middle of it...for now at least.

[JoMo]

Springfield AFD is really long and really detailed:

 

 

 

Precipitation should begin fairly rapidly Thursday morning, though
precipitation type remains difficult to pin down at this juncture.
Current indications are that the surface freezing line should be
roughly along a line from Branson to Salem, thus anything falling
over the northern two-thirds of the forecast area would be frozen or
freezing, with a small area over south central Missouri where just
rain would be favored, at least for a short time before colder air
builds south. Along with the surface temperature, the temperature
profile aloft will obviously be key to the precipitation type.
For areas north of I-44, it appears likely that 850 MB temps will
remain cold enough to either result in no melting of hydrometeors,
or just partial melting. In the low levels over this area,
temperatures will be cold enough for anything that (partially)
melts to completely refreeze, thus snow or a mix of snow or sleet
would be expected. By Thursday evening, any sleet should change
over entirely to snow.

Further south, along and south of I-44, things are a bit more
complicated. Temperatures around 850 MB will get progressively
warmer as one goes south, suggesting that the potential for partial
or complete melting of hydrometeors will become more likely further
south. At the surface and very lowest levels of the atmosphere,
there should be an axis where the low level cold air is cold enough
to refreeze anything that melts aloft before it hits the surface,
resulting in a mix of snow and sleet. If any precipitation melts
aloft and makes it down to the surface, and surface temperatures are
at or below freezing, then freezing rain would result.

It is important to note that precipitation type and amounts will
depend entirely on differences in temperatures at the surface and
aloft of just a couple of degrees, differences that are extremely
difficult to resolve this far in advance. With that said, it is best to
not focus on specific precipitation types or amounts for a given
location at this time, but instead just be aware of the potential
for accumulating wintry precipitation later this week. As the storm
system of interest and associated air masses are better sampled by
the surface and upper air observation network, specific details will
become more clear in the coming days.

Thankfully, by Thursday evening, any remaining precipitation should
simply change over to all snow as the colder low level airmass
continues to build in from the north. By Friday morning, the upper
level jet will realign itself from roughly Dallas to Toronto, and
strengthen considerably. Ascent within the right entrance region of
the jet should help produce another round of precipitation over the
region, especially the southern half of the forecast area, Friday.
The atmosphere is expected to be cold enough across the entire area
to result in all snow, with the potential for at least a few inches
of accumulating snowfall across the area by Friday evening.

As we head into the weekend, the core of the very cold Canadian
airmass will move south into the area, resulting in very cold
temperatures Friday/Friday night through Sunday. Lows will be in
the teens and single digits, with wind chills approaching zero.
Readings may need to be adjusted down a few degrees.

Finally, it appears that by next Sunday, yet another round of wintry
precip will move through the area as a stronger but much more
progressive shortwave swings across the area. Along with the
potential for some additional snowfall, it should bring a
reinforcing shot of cold air to the region, with temps likely
staying below freezing heading into the next workweek.

[wildweatherman179]

So pretty much I-44 75-100 miles on either side of it...you should make out with some pretty good snows. I'm ok with being in the 5 inch range on the south side of Tulsa. Something tells me these totals are very conservative. I think the cold air will firmly be in place so the sleet totals go down and therefore more on the snow side, but who knows. Glad to just be right smack in the middle of it...for now at least.

I would agree but I'm thinking more of an in between US 412 and I44 path. I think 10 inch through Monday totals could be likely in and around this area. Depends on the strength of the Sunday storm.

[JoMo]

Well I think that Frz rain looks to be likely along the I-40 area in OK and parts of NWA at the start before going to a mix of sleet also...but it could be sleet at the onset just going to depend on the depth of the cold air. Mostly all snow in SO MO.

Howdy, Spot... It's good to see you early this year, buddy!

 

Looking better for southern areas as time goes on. Ft. Smith area might be a mess of freezing rain though. All depends on the temps.

[JoMo]

Tulsa AFD for this afternoon is out now:

 

 

 

MEANWHILE...SFC OBS OVER THE NORTHERN ROCKIES SHOW THE ARCTIC
FRONT PLUNGING DOWN THE FRONT RANGE OF MONTANA AND HAS ALREADY
JUMPED THE CONTINENTAL DIVIDE. 1058MB CENTRAL PRESSURE ANALYZED
OVER YUKON TERR INDICATES THIS IS A SERIOUS ARCTIC AIRMASS HEADING
SOUTH...AND WILL START OUR DOWNHILL SLIDE ON WEDNESDAY. FOR NOW
HAVE TRENDED THE FORECAST TO A SLIGHTLY FASTER FROPA EARLY
WED...BUT SUSPECT IT WILL INITIALLY STRUGGLE TO CLEAR THE TERRAIN
OVER SE OK/NW AR BEFORE FINALLY ENVELOPING THE ENTIRE AREA BY
THURSDAY.

ABOVE MENTIONED UPPER SYSTEM WILL CONTINUE TO DIVE SOUTH AND
EVENTUALLY SET UP A FAVORABLE PATTERN OF WARM ADVECTION ABOVE THE
DEEPENING COLD DOME AND LEADING TO AT LEAST A COUPLE OF ROUNDS OF
WINTER WEATHER. THE INITIAL WAVE COULD BEGIN AS EARLY AS WED NIGHT
AND CONTINUING THROUGH A GOOD PART OF THURSDAY. SOME POTENTIAL
EXISTS FOR SIGNIFICANT ICING IN AREAS SOUTHEAST OF I-44 WITH
MAINLY SNOW AND SLEET TO THE NORTH. ANOTHER ROUND THU NIGHT AND
EARLY FRIDAY WILL LIKELY FOCUS A BIT FARTHER SOUTH WITH FROZEN
PRECIP FOR ALL BUT FAR SE OKLAHOMA BY THEN. AT THIS POINT THE
PRECIP AMOUNTS DO NOT LOOK ALL THAT HEAVY...BUT MORE THAN ENOUGH
FOR SIGNIFICANT TRAVEL IMPACTS OVER A LARGE PART OF THE AREA.

DRIER AIR WILL MOVE IN BY FRIDAY AFTERNOON BUT A PERIOD OF
FREEZING DRIZZLE MAY PERSIST AS MOISTURE REMAINS TRAPPED UNDER
COLD DOME. SOME CLEARING POSSIBLE BY SAT MORNING BEFORE ANOTHER
SURGE OF MOISTURE MOVES NORTH SAT NIGHT. MOSTLY SNOW WITH THIS
WAVE BUT TRANSITION TO FREEZING RAIN POSSIBLE IN THE SOUTH.
FORTUNATELY AMOUNTS LOOK LIGHT AT THIS TIME. COLD WEATHER WILL
CONTINUE FOR THE FORESEEABLE FUTURE.

[Spot]

Howdy, Spot... It's good to see you early this year, buddy!

 

Looking better for southern areas as time goes on. Ft. Smith area might be a mess of freezing rain though. All depends on the temps.

Heya!  Yea me to. Yea this system caught my interest enough to pop up early. Yea Fort Smith might be in for frz rain. I think up here its still looking like more Sleet then snow..bah.  If this cold air is deeper then we could all be in for more snow.. I sure hope so.

[Wx 24/7]

JoMO... you say that the SGF discussion is long and detailed as if it surprises you. I'm curious about precip type. That seems to be the trickiest part of this forecast.

[brettjrob]

I'd be careful along the I-44 corridor in OK of getting your hopes up on this one. I really think the current data supports a large swath of mainly sleet, with icing on the southern fringes and snow on the northern fringes. This is particularly true for the first wave on Thursday, for which I have almost no hope for anything but sleet in the OKC area. By Friday, assuming a second wave emerges with significant precip, we might at least have some shot at picking up a few inches toward the end. Tulsa is a little better off for snow prospects, but not much. Right now, I'd want to be about 50-100 mi. NW of I-44 from SE KS into MO as a snow lover... but of course many twists and turns are yet to come before Thursday.

[ouamber]

18Z GFS is REALLY trying to dump almost a foot on a pretty good swath of OK to NW AR/SW MO. Lawton, OKC, Tulsa, Bentonville, Joplin could all be looking at at least 6+ inches. CRAZY...

[wildweatherman179]

Lol. The models have reasonable agreement, but nobody else does. I love it. That's what makes this so much fun. I bet at least one of us is right. :-)

[David Reimer]

I'd be careful along the I-44 corridor in OK of getting your hopes up on this one. I really think the current data supports a large swath of mainly sleet, with icing on the southern fringes and snow on the northern fringes. This is particularly true for the first wave on Thursday, for which I have almost no hope for anything but sleet in the OKC area. By Friday, assuming a second wave emerges with significant precip, we might at least have some shot at picking up a few inches toward the end. Tulsa is a little better off for snow prospects, but not much. Right now, I'd want to be about 50-100 mi. NW of I-44 from SE KS into MO as a snow lover... but of course many twists and turns are yet to come before Thursday.

 

If I learned anything from the event two weeks ago in Texas (besides the hatred of thousands of snow lovers who get nothing) its that until we're within about 48 hours, everything is pretty much a guessing game. We'll see what happens, but I wouldn't be surprised to see the heaviest band of precipitation to shift about 150-200 miles over the next few days. 

[rockchalk83]

If I learned anything from the event two weeks ago in Texas (besides the hatred of thousands of snow lovers who get nothing) its that until we're within about 48 hours, everything is pretty much a guessing game. We'll see what happens, but I wouldn't be surprised to see the heaviest band of precipitation to shift about 150-200 miles over the next few days. 

 

With the last cold blast, the front ran 6-12 hours ahead of schedule...so don't be shocked if that happens again. That would tend to move the baroclinic zone and greatest forcing south like David alluded to.

 

As for me in Wichita, just looking like plain cold and a chance of light snow here for both systems.

 

Getting concerned that drought conditions may revisit the area if we don't get meaningful moisture soon. Been since early October since there has been appreciable moisture around here.

[JoMo]

Yeah, I'm also concerned the greater threat may shift farther south as we get closer to the event due to the cold air likely being quicker and farther south than the models think. 

[brettjrob]

If I learned anything from the event two weeks ago in Texas (besides the hatred of thousands of snow lovers who get nothing) its that until we're within about 48 hours, everything is pretty much a guessing game. We'll see what happens, but I wouldn't be surprised to see the heaviest band of precipitation to shift about 150-200 miles over the next few days. 

 

No doubt that more model mayhem is on the horizon. I just don't think in a broad sense that these clown maps and TwisterData snow maps are properly accounting for the warm nose by a long shot, so they need to be interpreted with extreme skepticism -- even after accounting for the possibility of spatial shifts. Sleet will probably be the rule over a large proportion of the precipitation shield, particularly the farther SW you go.

[wildweatherman179]

No doubt that more model mayhem is on the horizon. I just don't think in a broad sense that these clown maps and TwisterData snow maps are properly accounting for the warm nose by a long shot, so they need to be interpreted with extreme skepticism -- even after accounting for the possibility of spatial shifts. Sleet will probably be the rule over a large proportion of the precipitation shield, particularly the farther SW you go.

Snow map has little to do with some of my current thinking. There are many parts over each run that I consider. Not really thinking there will be as much of a warm nose in this.

[David Reimer]

No doubt that more model mayhem is on the horizon. I just don't think in a broad sense that these clown maps and TwisterData snow maps are properly accounting for the warm nose by a long shot, so they need to be interpreted with extreme skepticism -- even after accounting for the possibility of spatial shifts. Sleet will probably be the rule over a large proportion of the precipitation shield, particularly the farther SW you go.

 

True! If you want a better sense of the precipitation types and accumulations go to http://coolwx.com/ptype/. That's what I use for diagnosing accumulation types of FZ/Sleet/Snow. 

[wildweatherman179]

I'm not very good at this sometimes either. Lol. Still learning.

[JoMo]

Joe Bastardi blogged about the ECMWF model snow maps from WeatherBell. He says the maps are based on what the model itself is forecasting.

 

Of course the model could be and probably is wrong when it comes to specific amounts but it's good to see where the heaviest is supposed to fall based on where the model thinks it will be.

 

Other map sites like the "clown" map uses a different algorithm (Based on Kuchera) to calculate snow, which is why it looks different or has different amounts.

[The Waterboy]

Joe Bastardi blogged about the ECMWF model snow maps from WeatherBell. He says the maps are based on what the model itself is forecasting.

Of course the model could be and probably is wrong when it comes to specific amounts but it's good to see where the heaviest is supposed to fall based on where the model thinks it will be.

Other map sites like the "clown" map uses a different algorithm (Based on Kuchera) to calculate snow, which is why it looks different or has different amounts.

What did the 12z Euro show? I know maps can't be posted but do you have a recap of snowfall totals?

[JoMo]

What did the 12z Euro show? I know maps can't be posted but do you have a recap of snowfall totals?

 

For just the first system (both waves) through hour 108.. Accumulated snowfall on the 12z Euro was:

 

0.9" around Bartlesville, OK

1.6-2.0" around Tulsa

2.0" for Joplin

3.8" for Monett

4.2" for Springfield

NW Arkansas is a big jumble of numbers.. looks like between 4.5" (Bentonville/Rogers) to 6.1" (Fayetteville) in that area with areas farther east and southeast with the higher amounts.

Eureka Springs is probably around 4-6"

Ft. Smith around 4.6"

Just west of Ft. Smith in OK has between 5-5.6"

[JoMo]

Let's find the cold front on the NAM Thursday afternoon....

 

 

Well, that was easy....  The area of colder temps from SW OK up through NE OK into SW and Central MO is due to snow and ice accumulation from round 1.  Bullseye of higher totals for me on the 60+ hour NAM.... wait...that's probably not good.

[famartin]

I have placed a topic in the general forum regarding the revised NWS snow measurement guide...

http://www.americanwx.com/bb/index.php/topic/41853-new-nws-snow-measurement-guide/

[Wx 24/7]

Gotta love the NAM!!! LOL... it is always so juiced.

[David Reimer]

Another item to consider with the Friday morning event is that temperatures across Oklahoma will likely be in the low 20s. This could cause a slightly higher liquid-snow ratio. 

[MoWeatherguy]

Gotta luv that 12+' inch area at h84 on the NAM lol.

[Wx 24/7]

Gotta luv that 12+' inch area at h84 on the NAM lol.

Lock it in. Ha! Ha!

 

It has been consistently colder than the GFS. Hmm... something to consider.

[JoMo]

This is the 66 hour NAM 850 MB temps. This is at the height of round 1 of precip over the area. It's in C so 0 degrees is freezing. The light green is 0 to -2 and the light yellow is 0-2 degrees. Pretty tight gradient and that will probably mark the line between sleet to the southeast of the 0 degree line and snow to the northwest assuming there aren't any other pockets of warm air at different levels that don't have maps.

 

[JoMo]

00z GFS total frozen stuff for the upcoming system.... Curious how close that band is to the 850 MB front.