Chase Target for Monday, March 8
Chase target:
Roll, OK (30 miles northwest of Elk City).
Timing and storm mode:
Non-severe storms will be ongoing over the area through the early afternoon hours. Partial clearing will then take place over western OK after 3 PM, and a few discrete storms should fire in the target area between 4 and 5 PM, CST. Most storms should remain below severe limits; however, a brief, weak tornado or two cannot be ruled out. Storm motion will be towards the northeast at 35 mph.
Synopsis:
UA analysis indicated a closed H5 low over SRN CA/AZ; with 12hr height falls concentrated over SERN AZ. A second, weakening circulation was located over IA. An axis of 55F SFC dewpoints had worked into the TX panhandle in a region of SERLY SFC flow. Further W in ERN NM, clusters of mainly elevated storms were ongoing in a zone of WAA and large-scale assent.
Discussion:
Elevated convection will be widespread during the morning hours, with partial clearing taking place from southwest to northeast through late morning. Storms should redevelop near the triple point of an advancing DL/Pacific CF and the retreating WF, southeast of the SFC low over the OK panhandle. Significant SFC-3km SRH in excess of 300m2/s2 will exist well NE of the WF, with the largest hodographs remaining well E of the axis of modest instability. SFC-6km shear will also decrease throughout the afternoon with the approach of the ULVL system, however SFC-1km hodographs will increase after 00Z as the BL decouples and a southwesterly LLJ increases to 40-45 kts.
Instability remains the primary limiting factor for storm intensity, with MUCAPE’s AOB 700 J/kG. Mid-level lapse rates will increase later in the afternoon to 8-9 C/km in the H7-H5 layer as the cold core low approaches from the W; however, the steepest lapse rates will remain well NW of the retreating moisture axis.
- Bill
KD0DJG
www.twistertoursusa.com
9:57 PM CDT, 03/07/09
