Severe Weather Discussion for November 14 – 20, 2011.
– Showers and a few thunderstorms are possible on Monday, primarily in southeast Oklahoma.
– Severe thunderstorms are possible in western Oklahoma on Sunday.
– Temperatures will be in the low 70s Monday, near 70F Tuesday, mid 50s Wednesday, near 60F Thursday, mid 60s Friday, near 70F Saturday, low 70s Sunday.
– Severe Thunderstorms in Oklahoma: 25%
– Storm Chase: 10%
– Winter Precip; < 5%
After a very active start last week, this week will be much more quiet. Northern stream medium-wavelength trof will translate into the central U.S. on Monday as it picks up a closed southern stream low in Mexico. The latter system will move across Texas on Monday, allowing for much needed rain. For the most part, Oklahoma will miss out on this system, but southeast sections are likely to see some rain from it.
A cold front will follow the northern stream system late Tuesday, ending several days of warm temperatures across the state. Wednesday and Thursday will be cool with a warm-up into the weekend. ECMWF/GFS are in decent agreement regarding the development and progression of a southwest U.S. medium wavelength trof by next week. The main question will be how fast this system moves east towards Oklahoma. GFS was too progressive with the system last week and could be again this week. Although the GFS’s solution is certainly favorable for severe weather. The last frame of the ECMWF seemed to indicate the upper system would continue to dig southward will the GFS had already turned it east. Either way, moisture return and upper flow will be sufficient for severe thunderstorms whether it be Sunday or Monday. Question would be heating as that isn’t a given this time of year. I went ahead and put in severe for western Oklahoma on Sunday, so we’ll see how it all develops. GFS has a dryline on the TX/OK border at 6pm Sunday with at least low 60s dewpoints across the state. Wind speed and shear are both more than adequate for severe thunderstorms. Again, this is one model and seven days out, so the story may indeed change.
MOS numbers look acceptable this week with minimal tweaking.by