May 11, 2016: Mesoscale Analysis

The focus will be on the Dallas-Fort Worth (FWD) forecast area once again today.  This will be the 3rd day FWD will be focused on for convective initation and severe weather.

The Water Vapor Imagery at 1900 UTC shows west/southwest flow over TX/OK with a subtle mid-level short-wave approaching from thr 4-corners region and west TX.  At the surface, a weak boundary is approaching central and eastern TX.  This likely is the dry-line and a weak surface front.  The surface winds are N to NE over the pan handle of TX towards the Red River Valley in southwest OK, and southerly over the bulk of the FWD CWA.

 

The 1900 UTC RAP SBCAPE, Effective Bulk Shear (see below), and PWAT Analysis indicates another large instability, and weak to modest shear environment is in place similar to yesterday.  SBCAPE/MUCAPE values are in the 2000-4500 J/kg range (not shown) with Effective Bulk Shear values in the 20-25 kt range.  Multi-cells are likely with some supercells due to the abundant instability values.  PWAT values are generally in the 0.80-1.1" range.  Any super cells will likely be LP. 

The latest Metop satellite NUCAPS (IASI AMSU MHS+AVHRR) sounding (see below) for a point near KABI upstream of the Dallas Fort-Worth area futher exemplified the unstable environment.  Modified for a T=86F and a Td=66F, the SBCAPE/MUCAPE was 3521 J/kg, and the PWAT value was 0.82".  The mid-level lapse rates are extremely steep in the 7.8-8.0C/km range.  The Wet-Bulb Zero Heights are right around 9.0 kft AGL, and the Freezing Level Height is 12.0 kft AGL. -20C heights remain low at 20.8 kft AGL due to the steep lapse rates and the presence of the elevated mixed layer (EML).  The primary threats look like large hail and damaging winds again. The question will be whether the dry line and weak sfc trough or cold front will focus the convection quickly in the mid afternoon.

The focus will continue to be the west/northwest portion of the FWD area along the large instability gradient with the boundary approaching (see below). The latest visible satellite with Severe CI is below.  A cumulus field is approaching from the west/northwest portion of the FWD CWA.  Convective temps are right around 91F, so cells should begin to fire in the next hour or two.

-Yodamaster777