STATUS: IOP on 12-14 March
We will commence the first IOP of VORTEX-SE Saturday, 12 March. Observations will ramp up during the day, with boundary layer evolution observations underway by evening. We are anticipating the passage of two marginal systems during the weekend and Monday, the first on early Sunday morning associated with the remnants of the current deep system over Texas, and the second associated with a sharp mid-level wave on Monday morning. Potentially, we may stay through Wednesday to observe convection associated with a cold front passage. Thereafter, long-range guidance is hinting at a quieter pattern through the end of the month.
STATUS: IOP watch for 13 March and beyond (IOP has been cancelled for 12 March)
The consensus decision today is to not attempt to observe on 12 March because it the forecasted low-level shear is at the low end of the tornado climatology. Forecasted MUCAPE spans a range from 0 to ~1000, depending on the forecast model.
Another strong vorticity maximum approaches the region on Sunday, and we are now beginning to watch this feature, and watching how the overall pattern evolves beyond Sunday.
STATUS: IOP Watch
We continue to watch the forecast evolution of the lifting/weakening cutoff that will become a negative tilt shortwave late this week in the south, crossing AL early in the weekend. At this time, the forecast is for negligible chances for tornadoes with this system, primarily because of muddled and weak low-level wind profiles. We are monitoring to determine if there might be a short window of somewhat more favorable conditions. If so, studying the evolution of CAPE and shear in this scenario might be scientifically valuable.
Following the Friday/Saturday event, another fairly strong shortwave should pass near or north of AL on the 14th; the development of adequate CAPE remains uncertain.
A final IOP decision will be made in briefing tomorrow, Tue 8 March.
We continue to watch for a short window of opportunity sometime toward next weekend, when an upper low weakens and lifts northeast from TX. There is a chance that a weak warm front will exist near the observing area, with light east-southeast winds beneath strong southerly flow aloft, leading to sufficient low-level shear for tornadoes. An IOP decision is anticipated around Tuesday.
The remainder of March appears to offer additional deployment chances, but the forecast uncertainty continues to be very large.
We are still watching the system that is about to dig into Mexico (with thickness < 540 dm well south in Mexico on the operational GFS this morning!). It should lift northeast and weaken rapidly toward the end of the week. At this time, it appears unlikely that this will allow for tornado-favoring wind profiles, but it’s too early to dismiss the threat completely.
Mid-month still looks more interesting.
We are continuing to watch the system that will cut off in south Texas early in the week. It appears it will weaken and lift northeast as a negatively-tilted wave, with possible favorable shear in the Thur-Fri time frame. Right now, the flow is forecast to be unidirectional, but details may change in the coming days.
We anticipate an IOP decision around Monday.
There may be two back-to-back IOPs in mid-March… one for the lifting trough, and a second one for a more promising looking system a few days later.
NOAA has published a Federal Funding Opportunity announcement for VORTEX-SE in grants.gov. To find the text of the announcement, follow these steps:
1. At grants.gov, use the search feature to locate the announcement NOAA-OAR-OWAQ-2016-2004838
2. Select the announcement package
3. Click the “Package” tab, do the registration and press “Submit”
4. On the resulting page, in the lower left, click the “Download instructions” button.
Status: IOP watch
We are monitoring the evolution of the forecast for a strong system coming onshore and progged to become a cutoff low in the vicinity of south TX. An IOP decision will likely be made late this weekend.