10 January 2020 – Southern Plains Severe Weather event with Elevated Mixed Layer (EML)

CIRA ALPW for 10 January 2020

On 10 January 2020, SPC issued a moderate risk of severe thunderstorms for portions of Oklahoma, Texas, Louisiana, Arkansas, and Mississippi

One of the favorable ingredients for this severe weather setup was the presence of an Elevated Mixed Layer (EML) which is depicted in the 12z Fort Worth, MS, Norman OK and to a lesser extent the Little Rock, AR soundings:

At least in the Ft. Worth and Norman soundings the EML is bounded between the capping inversion around 800 mb and the higher RH around 650 and 350-375 mb. Within this layer, the relative humidity is quite low with a source region off the elevated plateau of northern Mexico
At times, the EML may show itself as a region of warming brightness temperatures in the GOES 7.3 micron imagery. In this particular case, the region of warming brightness temperatures may be traced back to diurnal heating from the previous day over the elevated Mexican plateau and advecting nor eastward across Texas, Oklahoma, and Arkansas

https://rammb-slider.cira.colostate.edu/?sat=goes-16&z=0&im=12&ts=1&st=20200110090117&et=20200110160617&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=conus&p%5B0%5D=band_10&x=5000&y=5000

Alternately, also available here:

http://rammb.cira.colostate.edu/templates/loop_directory.asp?data_folder=training/visit/loops/10jan20/band10&loop_speed_ms=60

 

ALPW is a product based on microwave instruments aboard polar satellites which can see through most clouds, The 700-500 MB layer is useful in that it depicts the source region(Mexican Plateau) of the dry air associated with the ELM and it can be tracked towards Texas, Oklahoma, Arkansas, Louisiana and NW Mississippi, This dry air exists underneath a moist air mass with origins from the Gulf of Mexico as seek in ALPW in the lower layers.

ALPW Loop:

http://rammb.cira.colostate.edu/templates/loop_directory.asp?data_folder=training/visit/loops/10jan20/alpw&loop_speed_ms=120