VORTEX-SE In the Field

We are approaching the end of ops for today.  The richer air didn’t surge north ahead of the convective system as strongly as forecast.  Earlier, there was a fairly intense low-level vortex west of Columbus MS, near where the warm front intersected the QLCS.  But the cold pool eventually overtook this part of the system.  In the main part of the domain, the convective system has been fairly benign.

Next update likely to be tomorrow.

STATUS: Ops in progress

Initial soundings have begun, and all mobile observing crews are now being deployed toward the west.  There is a fairly vigorous QLCS moving through MS, and should enter AL about 21-22Z.  A warm front is lifting slowly N, and might enter the SW part of the domain before the QLCS arrives.  Just along and north of the warm front, low-level shear should be enhanced, increasing the likelihood of low-level rotation.  The QLCS structure and evolution will be influenced by the large gradient in CAPE and low-level evaporation potential across the domain.

Ops are possible tomorrow, with the current expectation being potentially severe activity somewhere in the domain.

There will be other updates today (hopefully).  There will be a 1 PM briefing/planning meeting on Saturday.

STATUS: IOP

It now appears that a QLCS will cross the domain during the afternoon and early evening.  There is some potential for vortices associated with this system.  All participants are invited to report to SWIRLL as soon as possible to begin working on today’s science plan.

STATUS: IOP continues

No significant activity is expected on Thursday.

Another briefing and science planning meeting will be held Friday at 1 PM.  We anticipate the possibility of late-day activity on Friday.  There should be some storms to observe on Saturday, and perhaps on Sunday as well.

STATUS: IOP

We are in our last IOP for the Spring 2016 campaign.  Scientists will meet today at 1 PM at SWIRLL for a brief discussion of the prospects for the next few days.  The meeting will be available via GoToMeeting.

The weather is tranquil across northern AL this morning, so operations are not currently expected today.  More information about Fri-Sun will be in an afternoon status update.

STATUS: IOP

The evolution of today’s weather is very uncertain.  There is a squall line to the west of the area that could advance through the study area this afternoon.  Or it could weaken/dissipate, and be followed by new activity late this evening/tonight.  Or… name your scenario.

Because of the uncertainty, the sounding systems will be deployed near TTU Stesonet fixed surface observing sites, and study the evolution of CAPE.  It should be noted that at least on set of numerical guidance suggests that CAPE will remain small, and then go to zero for the remainder of the day as the cold pool from convection to the west advects across the area, or is renewed if the convection persists.

The in situ observing platforms will remain close to Huntsville until the evolution becomes more clear, and a target storm can be identified.  The MAX mobile Doppler radar will be deployed to Courtland AL airport, and the Purdue X-POL likely will go to the Tanner site later this afternoon.

STATUS: IOP

We are still expecting convection tomorrow (Wed) evening.  Observing is expected to begin midday to monitor the evolution of the boundary layer and mesoscale features.  There will be a PI science planning meeting to design the day’s observing strategies at 10 AM at UAH SWIRLL.

Another episode or two of convection may occur as the week goes on and into the weekend, so the current plan is for this IOP to continue until the weather settles down, or project resources/participants are exhausted.

STATUS: IOP

The final VORTEX-SE IOP for the Spring 2016 campaign will begin Wed 27 April.  Current guidance suggests the possibility for HP supercells and/or a QLCS system Wednesday evening or night.  We will have a science planning meeting at UAH on Wed morning or midday.  The time of this meeting will be decided in the usual 1 PM conference call on Tue 26 April and will be posted on this blog as well.

There should be a continuing period of occasionally sufficient mid- and upper-tropospheric flow for supercells, and occasionally augmented low-level flow and shear, as well as CAPE, between the Wednesday event and ~ Sunday 1 May.  Thereafter, it looks like general ridging in the central US and a deepening trough to the east will bring cooler, drier continental air into the VORTEX-SE domain.  So this IOP will probably involved 2-3 observing periods.

(Dates corrected… thanks to the observant VORTEX-SE fan in Kansas.)

STATUS: IOP Watch

We continue to watch the weather expected between about Thur 28 April and 2 May.  A decision is expected tomorrow on a possible deployment to N AL for observations beginning Thursday.  At this time, it appears that the first system will likely be very marginal for tornado potential, but a stronger system at the start of May has larger potential.

STATUS: IOP watch

We are watching two systems.  The first is the major wave that will move into the Plains on Tuesday, and then begin filling and moving northeast on Wednesday.  It’s possible that the southern end of this strong forcing will be in ~ eastern AR, in a region where roads and terrain do permit mobile operations.  We would not have 100% of the platforms participating because of conflicts with academic schedules.  Another wave follows this first one, and right now it appears that this one will take a more eastward track and possibly move through northern AL with an attendant week surface boundary around May 1.  If the investigators decide to operate in the MS Valley mid-week, they would retreat toward N AL for the weekend.

Right now, neither scenario looks particularly promising for tornadoes.

A decision on the mid-week MS Valley deployment will be made tomorrow 24 April.