Weather Info/Links From Greg Whitworth

I'm short on time to write a forecast discussion since I too was one of the people out getting groceries last night. I want to make you aware of some weather links you can check yourself to get snow forecasts and maps; the same information I look at.

I'm quite concerned about a major event. The ECMWF model has been saying this system will track across slower than projected. The NAM and GFS models are slowly catching onto this and with each version, are increasing the total amount of moisture in the forecast. It's now well over 2" in OKC and in one case, the NAM was dumping out 3" of moisture over OKC. I'm less concerned about the panhandle, I don't think the impacts will be quite as high as what the models have been saying.

This system looks to take a trek very close to the December 24th storm. That means heavy snow in central and southern Oklahoma. Unfortunately, the cold air doesn't look as deep as it did with the December 24th storm, which means there may be some significant icing especially central and southern OK before the change over to snow.

I think the ice will begin around sunrise on Thursday and change to snow near mid-afternoon to sunset in central OK, and sooner in northwest OK. I haven't looked at too many detains for the northwest part of the state, but that's why I'm providing links to the maps so you can look for yourself.

We're talking about a significant, possibly historical event; one that will likely require another disaster declaration for some parts of the state. The models are dumping out over 10" of snow in the main band with anywhere from 1/4 an inch of ice to nearly an inch. They are very persistant with the high totals for the most part. See the maps to know if your area is going to be one of the high impact areas. I will try to write a forecast discussion up sometime this evening.

Here's a timeline chart forecast for Norman, OK produced by a computer at WLNS TV in Lansing, Michigan. It takes all the model information, reprocesses it, and dumps out snow and ice total forecasts. Keep in mind this forecast is ONLY for Norman, OK and the computer does not do any other cities.around here other than Amarillo and Wichita.
It has the date and time in GMT, the wind, Here's what the categories mean:
SfcT = surface temperature
Ptype = preciptation type
SRat = snow ratio, 1 inch of rain equals this many inches of snow (for instance 15 inches of snow to 1 inch of rain)
TotSN = total snow
TotQPF = if you melted the frozen stuff, how much rain it would be (the liquid equivalent of the event)
TotPL = total sleet
TotZR = Total Freezing Rain

http://66.70.209.226/weather/snow/oun.txt


Here's another site I use a lot. Earl Barker's modeling site. It has total snowfall and total ice on a map. The site is somewhat complex, so let me explain what you should look at and give some shortcuts.

http://www.wxcaster.com/models_main.htm

The links like this are the ones you'll want:

NAM Radar Site Snowfall Overlays: NAM Snowfall - fixed 12/08/2009 0630Z
http://wxcaster.com/gis-snow-overlays.htm
Click on the dot on the map.
Total snow from the NAM model for it's versions that come out around 10 pm and 10 am.

GFS Radar Site Snowfall Overlays: GFS Snowfall
http://wxcaster.com/gis-gfs-snow-overlays.htm
Click on the dot on the map.
Total snowfall from the GFS model for it's versions that come out around 10 pm and 10 am.

More regional maps and ice charts:
Region Snowfall: Regional Snowfall
NAM snow (the version that comes out around 10 am and 10 pm):
http://wxcaster4.com/nam/CONUS1_ETA212_SFC_ACCUMSNOWFALL-KUCHERA_84HR.gif
NAM sleet accumulation:
http://wxcaster4.com/nam/CONUS1_NAM212_SFC_ACCUM-SLEET_84HR.gif
NAM freezing rain accumulation:
http://wxcaster4.com/nam/CONUS1_NAM212_SFC_ACCUM-FZRN_84HR.gif

NAM model (the version that comes out around 4 am and 4 pm):
Total snow:
http://wxcaster4.com/nam/CONUS1_MESO-ETA212_SFC_ACCUMSNOWFALL-KUCHERA_84HR.gif

GFS snowfall (10 am and 10 pm version):
http://grib2.com/gfs/CONUS_GFS0P5_SFC_ACCUM-SNOW_84HR.gif
GFS freezing rain:
http://grib2.com/gfs/WINTER_GFS0P5_SFC_ACCUM-FZRN_84HR.gif
GFS sleet:
http://grib2.com/gfs/WINTER_GFS0P5_SFC_ACCUM-SLEET_84HR.gif

GFS snowfall (4 am and 4 pm version):
http://wxcaster4.com/gfs/CONUS2_GFS0P5_SFC_ACCUM-SNOW_84HR.gif
GFS sleet:
http://wxcaster4.com/gfs/CONUS2_GFS0P5_SFC_ACCUM-SLEET_84HR.gif
GFS freezing rain:
http://wxcaster4.com/gfs/CONUS2_GFS0P5_SFC_ACCUM-FZRN_84HR.gif

Greg Whitworth