April is normally one of the top three severe weather months (behind May and June), but it has been extraordinarily quiet this year.
In fact, a scant 17 tornadoes have taken place from April 1-21, a period during which more than 100 twisters take place in an average year.
The numbers year-to-date for 2010 are equally telling. There have been 83 tornadoes in the entire United States since January 1; this is only 31% of the 55-year average of 265 tornadoes. This sets a new record low of tornadoes year to date, beating the previous record by more than 30 twisters.
UPDATE: Thu 22 April 2010 / 3:50pm
Little change in my forecast, but now it appears the storm threat will come in two waves: One Friday morning for all of Texoma, and a second event late Friday/early Saturday for the eastern half of the area. Stay tuned; this type of situation will require fine tuning as the event draws closer.
Primary threats will be damaging wind and hail, but an isolated tornado is always possible in any severe storm environment.
==========================MONDAY'S ORIGINAL DISCUSSION==================
Now, we face the potential for a significant severe weather outbreak Friday as an intense upper level low slowly moves our way from the west. We’ll need to keep an eye on this one because there will be plentiful moisture in place, along with considerable wind shear and warm temperatures.
The system may pass through overnight, or cloud cover could limit daytime heating (and surface based energy). Either of these situations would lower the potential for severe weather.
On the other hand, if these elements line up during peak heating of the day Friday then portions of the southern Plains could get some very rough weather indeed.