Simon Brewer
EF3
Possible cold-core tornado event for Monday December 19th anywhere between SE NM and SW OK: mid-level closed low ejecting out of the Southwest and over the southern Plains. There are many parameters, which have to fall into place to get a cold-core tornado event (much like any tornado event). My biggest concerns for the setup are timing of the mid-level closed low, cloud cover, and, almost always, low-level moisture. If the timing of the mid-level low is good and the moisture is there (only mid 40's to low 50's dewpoints) this event might happen. I've had my eye on this wave most of the week; the models don't handle closed-lows very well, but they've been relatively consistent with the forecast.
12Z NAM December 16th Forecast for 18Z on December 19th:
Nose of upper 40's-low 50's dewpoints into NW TX
Sfc temperature axis going through Childress, TX
-5 deg C 700mb temps advecting over NW TX
-20 deg C 500mb temps adevecting over NW TX
intense PVA over NW TX
12Z GFS forecast is very similar to the NAM, but slower with all the same parameters over SE NM/W. TX border.
Also, there is the possibility of a snow storm between Beaver, OK and Greensburg, KS that night, so that could be a double tornado/snow chase. There are still random aftershocks near Prague, OK, so an earthquake chase is possible if this setup doesn't occur.
Simon
12Z NAM December 16th Forecast for 18Z on December 19th:
Nose of upper 40's-low 50's dewpoints into NW TX
Sfc temperature axis going through Childress, TX
-5 deg C 700mb temps advecting over NW TX
-20 deg C 500mb temps adevecting over NW TX
intense PVA over NW TX
12Z GFS forecast is very similar to the NAM, but slower with all the same parameters over SE NM/W. TX border.
Also, there is the possibility of a snow storm between Beaver, OK and Greensburg, KS that night, so that could be a double tornado/snow chase. There are still random aftershocks near Prague, OK, so an earthquake chase is possible if this setup doesn't occur.
Simon