GOES-14 will be in Super Rapid Scan Operations for GOES-R (SRSOR) mode between 18 May – 12 June, 2015. This special mode allows for 1-minute temporal imagery for GOES, similar to what will be available when GOES-R becomes available in 2016.
We will discuss the 1-minute imagery over Texas on 19 May, 2015.
First, we will look at the early period between 1730 to 1940 UTC:
Regions of convection at this time include:
1) southeast Texas (moving southeast), which leaves behind a stable air mass (clear area to its northwest)
2) central Oklahoma
3) eastern Texas panhandle moving into western Oklahoma
Next, we turn our attention on southwest Texas. We see indications of developing cumulus along a dryline (clear to the west). The northern portion of the developing cumulus has multiple failed attempts at convective initiation since the anvils get detached (commonly called orphan anvils) from the main updraft base. By the end of the loop we begin to see more robust looking cumulus slightly further south down the dryline.
Next, we’ll look a the period between 1941 to 2136 UTC:
We keep our attention in southwest Texas along the dryline and note that convective initiation occurs in two areas (a northern area and southern area), along the dryline. The northern area continues to show the earlier trend, which is soon after development the storms dissipate (perhaps moving into more stable air?) then another storm develops and follows the same fate. Meanwhile the storm to the south quickly expands and intensifies with multiple reports of tornadoes associated with it. We see cumulus streets just southeast of this storm indicating an unstable air mass that is feeding into this storm. We also see a nearly east-west oriented line of cumulus on the western flank of the storm. This appears to be a pre-existing convergence line that is augmented by the flanking line of the storm itself. Note the northern storm eventually dies off by the end of this loop, storms had struggled to persist in this region earlier, and now with the larger storm to the south it may have completely cutoff the inflow into the northern storm.
Look at convection developing in other parts of Texas and Oklahoma, notice how much more clear features appear in 1-minute imagery relative to what you are used to analyzing. A cold front exists in the northern Texas panhandle extending northwest into northeast New Mexico, stratus clouds and/or stable wave clouds exist behind the cold front. Any convection that crosses the cold front briefly are enhanced along the cold front but quickly dissipate as they move to the cold side of the front where CAPE goes away. The convection in western Oklahoma leaves behind an outflow boundary that may play a role later in the day.
Now we will consider our final loop between 2137 to 2349 UTC:
Our storm in southwest Texas continues to exhibit numerous characteristics of a severe storm – overshooting top, back-sheared anvil, crisp edge to the anvil cirrus, flanking line with enhanced cumulus and unstable air (cumulus streets) feeding into the storm. Note the weaker storm that developed near the Mexican border and moved north, the pulsing updraft with that storm can be followed underneath the anvil cirrus of the dominant storm for a while. It looks like it moves just east of the main updraft of the more intense storm.
In the Texas panhandle, we see an MCS outflow boundary that originated from the MCS in western Oklahoma oriented ESE to WNW with an area of convection riding along that boundary that seems to enhance the intensity of the convection. Further north and west, we see the cold front with its stratus clouds behind it, and any convection that crosses it towards the cold air quickly dissipates.
Further east, just west of the Dallas metroplex and south of the Oklahoma-Texas border we see a number of new thunderstorms developing. A number of these were severe including tornadoes. Note the anvil orientation is towards the southeast, different than some of the other anvil orientations we were looking at for other storms. Remember that anvil orientation is a function of the vector difference between the mid-level steering flow (in this case west-southwest) and storm motion. The storm motion varies across Texas, accounting for the different anvil cirrus orientations that we observe.
Real-time 1-minute imagery may be viewed here:
Also, be sure to check out the CIMSS Satellite blog entry on this same event: