This is going to be a big one. Particularly West and North of KTGX.
The Big Picture: It appears nearly certain that some nice convective bands will set up somewhere in SC/SE Nebraska (into North Central KS?), spelling double-digit snowfall totals for much of the area, and even more importantly, some isolated 20-25″ totals. That will be the headline of this event. Widespread interstate and airport closures seem likely for tomorrow through Tuesday. I currently tend toward the GFS solution: to place the bull’s eye for snowfall totals in South Central NE and extending into North Central KS.
The 48 hr GFS:
While the 48 hr NAM seems to be favoring a snowfall maxima slightly farther East into SE NE (note: this is a snowfall product only) which would be great for KTGX:
Locally: I don’t think I could pick a tougher location to forecast for relative to this system owing to the incredibly tight gradient of snowfall totals likely to be stretched across this region. Here in Northeast KS, today’s warm air is a bit of a concern, with a current SFC temp of 44ยบ. While some light rain showers moved through the area this AM and tried to moisten it up a bit, the warmer, drier air is winning out. While the GFS and NAM are in agreement through about 18Z MON, they begin to diverge thereafter. The GFS is more bullish, pushing the colder air in place to force a switch over from rain to snow prior to 00z Tuesday, while the NAM is a bit more conservative, lagging behind by a couple of hours. The later is the trend I tend to favor. It is currently holding a small nose of warm surface temps along the KS/MO border that have verified through this afternoon. I don’t believe the GFS is accounting for this warmth accurately. I doubt sub-freezing sfc temps will verify until the mid-afternoon hours at the earliest, putting our best snow accumulation window at ~00z - 06z Tuesday. That said, the snowfall is already piling up ahead of forecast in CO and NE; the changeover occuring earlier than the NAM or the GFS had for those areas, leading me to hope that we can exact the same fate for our area from this system. I had been wondering a bit about the dry slot affecting our area…as of this morning’s model runs, I’m less inclined to think it would be a problem.
The Bottom Line: Considering the continued slowdown of the system, I’m going adjust yesterday’s numbers a bit. I see a changeover from rain to snow occuring later; around 00z Tuesday (6pm Monday) and an increase in the forecast snowfall total to 5-7″ for KTGX.
Note: The KTGX Discussion Forums appear to be down at the moment, but posts can be made at the bottom of this post with the “Comments” button.
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Some links that will be handy over the next 48 hours or so:
NOAA Interactive Snow Maps
Snow Depth: USAF Analysis Wunderground
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March 19, 2006 at 6:49 pm
Anonymous
Been too busy with work and the OK scene, but just ran Bufkit for TOP and Snow total would be near 14″, GRI about 30″ and about 25″ for Coffeyville. If you want to believe that.
March 19, 2006 at 6:53 pm
Jake
WOW!
I’m not ready to discount the GRI number, although the TOP number I’d be shocked by. This damn warm/dry air that is in place is driving me nuts! Just last hour, KCI was at 44/20! OUCH! That’s going to take a while to saturate, not to mention cool.
I think the NAM and GFS both have a great handle on the moisture, just not the warmth that is in the area. I’m crossing my fingers we can get the cooling machine cranked up over the next 24 hours or so.
It just began raining here again this hour, but it is still 44 and the sun has set.
March 20, 2006 at 1:30 am
Anonymous
Hey, does this mean you’ve come around to my guess of 6 or 7? Haven’t been liking the NAM much recently (or all winter), but earlier today it and the GFS were a bit closer; would say something about the GEM, but this is too far south for it to be reliable. There were some crazy numbers for the formulas we use w/ the GRADS stuff @ work, ~ 30″ bullseyed over Lincoln in the 12z NAM. This afternoon I had 8-10″ for DDC through 00z Tues.
For me, the biggest problem was that a changeover in the models was relying on a shallow layer of -1C to -3C air to hold all day and based on the sfc obs that didn’t happen.
March 20, 2006 at 4:53 am
Jake
I don’t think those GRADS numbers are all that unreasonable for portions of SC and SE NE. With convective bands setting up, totals in excess of two feet are certainly likely.
Here in KTGX, sleet has been singing on the N and E windows for the past couple of hours, with about a quarter inch of liquid falling so far. We’re still at 36, although that’s cooler than I thought we’d be at this time. I wrote more about it on the message board and will try to get a couple more hours of sleep before checking out the 12z model runs.