Severe Weather Discussion for July 18 – 24, 2011.
– A few thunderstorms are possible most any day this week, although better chances appear Friday-Sunday. Severe chances are low, but not zero.
– Temperatures will be in the 102-105F range Monday-Sunday.
– Severe Thunderstorms in Oklahoma: 5%
– Storm Chase: < 5%
– Tropical Development: 15%
Little change to the going forecast this week. Despite 500mb heights of 596dm, temperatures in OKC have struggled to reach 100F. Upper ridge is forecast to weaken some and shift northeast later in the week as a medium wavelength trof develops to the west. This trof will do little for the region with the main influence southerly flow on the west side of the ridge. A few easterly waves look to move near the region with the best potential later in the week for rainfall. However, even that is low but POPs are still warranted.
Climatological temperature max occurs today through August 13th, so the heat will remain and this is also a given per very dry ground. Latest drought monitor shows much of western OK in a D4 and all of Oklahoma in a drought, the majority D1 – D4. OKC has reached or exceeded 100F 27 times this year, now 23 away from the record set in 1980. The current consecutive days is 5, with the record 22. GFS still hasn’t gotten a clue and is ignored. The ensembles seem to be catching on but the operational GFS is still out to lunch. NAM/ECMWF have performed well and will stay with them on temperatures. I didn’t get too fancy this week, as I don’t see much of a spread during the week. Potential for thunderstorms Saturday-Sunday may be enough to shave a few degrees off like last Tuesday/Wednesday.
Tropics got active as we have TS Bret. I went with 15% as it will be around this week but is not a threat to the U.S. at this point.by