STATUS: IOP Watch
We are anticipating a possible IOP on Saturday and Saturday night.
A trough will deepen across the northern High Plains late Friday, causing an acceleration of the flow in the upper atmosphere across OK on Saturday. This trough will consolidate somewhat as it approaches MO/AR, and a surface low will deepen fairly rapidly somewhere in the region centered near Memphis.
The developing southerly flow should bring Gulf moisture back into the Arklatex region Friday night, although the confidence in the “quality” of this moisture is not high. A series of runs of the operational GFS show a subtle decrease with time in the forecasted dewpoints across the region on Saturday, and an associated decrease in CAPE. We expect that drier air will remain in place across GA, and perhaps parts of AL, because the pattern and fast-moving wave will not allow moisture to return to those areas. So any complex of storms that develop in the Arklatex region Saturday will eventually run out of juice as they race east.
Another question (seemingly always a major issue in VORTEX-SE) is the likelihood, timing, and effect of an MCS in the Gulf of Mexico. These systems are probably associated with subtle waves in the jet stream, and those waves may not be well forecast until within 24 hours of passage because prior to that time they are somewhere out over the Pacific.
The current best guess is that storms will form in far east Texas on Saturday, with at least some tornado potential, and roll east across Louisiana in the evening, and perhaps into MS/AL during the night. We expect that our most likely subdomain for combined airborne and surface radar observations will be the U. Louisiana-Monroe subdomain.
Bear in mind when reading these discussions that we are forecasting conditions required for successful research operations. We have a very high tolerance for erroneous forecasts of possible tornadoes; they are a rare phenomenon and it is a lot more painful to miss an observing opportunity than it is to be operating and nothing happens.
A final IOP decision will be made Thursday afternoon, 8 March.