Chase target for Monday, January 16
Chase Target:
Lufkin, TX.
Timing:
This will be a late morning event. Rain and embedded storms should initiate near the Nacogdoches and Henderson, TX areas around 10 AM CDT. Within a few hours, a large expanse of storms and rain should fill into the region in an area in TX bounded to the N by I-20 and to the W by I-35.
Storm type and intensity:
Given the overall lack of instability coupled with fairly strong dynamical forcing, storms will quickly evolve into a number of fast-moving lines. The largest threat for any marginal severe WX will be wind gusts to 50 mph.
Discussion:
00Z UA analysis indicates a highly amplified, full latitude, and positively-tilted trough in the WRN CONUS. A 150kt H3 streak extends from NWRN Mexico into CNTRL OK, while another piece of energy is diving S through NRN CA. At the surface, meager SFC moisture was lifting NWRD into SERN TX, with Td’s AOA 50F S and E of a GRK/CRS/TYR line. A moderate SWRLY LLJ has developed in this area, and this feature will only back slightly by mid-day tomorrow; which should serve to keep any Gulf moisture return confined to a very shallow layer in all but the very SERN part of TX. Better moisture return is underway further to the E, as indicated by a nearly 150mb-deep moist layer on both the 00Z SHV and LCH soundings.
Tomorrow, a highly divergent right-entrance region of a 170kt H3 streak will be positioned over ERN TX, while a number of mesoscale disturbances will approach the area. Buy mid-day, a “Lead†vorticity ribbon is advertised to be aligned along a LBR to GRK line, while a more significant disturbance will be oriented along an SPS to SJT line. Throughout this period, UVV’s will rapidly increase and precipitation should initiate in ECNTRL TX where the CAP will erode first, well S and E of significant SFC boundaries. Despite SFC Td’s into the low 60’s, the shallow nature of the nature of the moisture along with widespread cloud cover will contribute to very low mixed-parcel CAPE’s. This alone should minimize severe potential, despite impressive shear parameters (SFC-6 km shear to 70 kts).
- bill