Severe Weather Discussion for January 30 – February 5, 2012.
– Showers and a few thunderstorms are possible in eastern Oklahoma Tuesday afternoon and evening. And again, Friday, although central Oklahoma may see some showers. Snow maybe possible next weekend, but low confidence right now.
– Temperatures will be in the mid 60s on Monday, upper 60s Tuesday, upper 50s Wednesday, mid 50s Thursday, low 50s Friday, near 40F Saturday, and low 40s Sunday.
– Severe Thunderstorms in Oklahoma: 5%
– Storm Chase: < 5%
– Winter Precip: 15%
Zonal flow will continue for a few days before the CONUS pattern significantly amplifies. Models are in decent agreement through 72 hours and then exhibit unusual disparity beyond that point. Seemingly this is due to the forthcoming pattern change, which the models rarely handle well. To that end, the forecast beyond Thursday is low confidence and high bust potential.
Shortwave trof will translate across the region on Tuesday in progressive zonal flow. Said trof will induce a surface low, which is progged to drag at least low 50s dewpoints into the state by Tuesday afternoon. Degree of heating and moisture return will provide at least a small opportunity for thunderstorms. In general, showers are the more likely type. Location of moisture return points to eastern Oklahoma being the primary area for any rain. After Tuesday a weak Pacific cold front moves through, knocking highs down a little. 18z GFS is more robust with cooling for Wednesday, so this is reflected in my temps.
Upper system then forms near or just west of the region by Friday. Models differ greatly on the development of this system along with subsequent movement and impacts. Moisture availability remains high in the Gulf through much of the week, such that any system that can tap it will provide precipitation. Persistence would argue for all rain no mater what, but climatology argues for snow chances. So, that is the difficulty of forecasting this week. The ECMWF’s pattern would seemingly favor snow next Saturday, to which I’ll just have to wait and see. Special discussions may be required if a snow threat develops, hence the 15% chance. It is a gamble, but we’ll see.
Went above MOS Monday/Tuesday, then with Wednesday/Thursday and below the remainder of the week. As noted above, potential for colder temperatures Saturday and Sunday but I think the going numbers are cold enough for now.by