Alert archive / Texas / Mesoscale Discussions in 2016
Mesoscale Discussion 528
The Storm Prediction Center issued this mesoscale discussion at May 2, 2016, 12:38 AM CDT for Starr County, Zapata County, Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 2, 2016, 12:38 AM CDT (05:38 UTC)
- Expired
- May 2, 2016, 2:45 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Starr County, TX, Zapata County, TX
The radar
The Brownsville radar (KBRO), 177 km from the middle of the area, began a volume at 05:39 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Brownsville Intl, TX (KBRO), launched 00:00Z, 5.6 hours before the alert went out and 179 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1767 J/kg
- Mixed-layer CIN
- -153 J/kg
- Mixed-layer LCL
- 826 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- -7 m²/s²
- 0-3 km storm-relative helicity
- 46 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.2
The text
As transmitted.
548
ACUS11 KWNS 020538
SWOMCD
SPC MCD 020538
TXZ000-020745-
MESOSCALE DISCUSSION 0528
NWS STORM PREDICTION CENTER NORMAN OK
1238 AM CDT MON MAY 02 2016
AREAS AFFECTED...LOWER RIO GRANDE VALLEY
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 020538Z - 020745Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...SUPERCELL ALONG THE NUEVO LEON AND TAMAULIPAS BORDER
SHOULD AFFECT PARTS OF THE LOWER RIO GRANDE VALLEY ON ITS CURRENT
SOUTHEASTWARD TRACK. LARGE HAIL /INCLUDING HAIL ABOVE 2 INCHES IN
DIAMETER/...SEVERE WIND GUSTS AND A BRIEF TORNADO ARE ALL POSSIBLE.
LIMITED SPATIAL EXTENT OF THE THREAT MAY PRECLUDE WW ISSUANCE.
DISCUSSION...SUPERCELL DUE WEST OF ZAPATA COUNTY IS CURRENTLY MOVING
SOUTHEAST AROUND 25 KT. EXTRAPOLATION RESULTS IN THE HAIL CORE
REACHING THE RIO GRANDE BETWEEN 0630-0700Z. WITH MODEST EASTERLY
LOW-LEVEL WINDS PER CORPUS CHRISTI/BROWNSVILLE VWP
DATA...SUBSTANTIAL VEERING OF THE WIND PROFILE WITH HEIGHT WILL BE
FAVORABLE FOR MAINTENANCE OF UPDRAFT ROTATION. GREATEST UNCERTAINTY
IS IN THE DEGREE OF MLCIN AND ITS SUBSEQUENT EFFECT ON THE LONGEVITY
OF THIS SUPERCELL. BUT GIVEN ITS WELL-DEVELOPED NATURE AT BASE RADAR
SCANS /WHICH ARE STILL AROUND 20000 FT AGL AT THIS TIME/...IT SEEMS
PLAUSIBLE THAT THIS SUPERCELL WILL AFFECT AT LEAST A COUPLE COUNTIES
IN DEEP SOUTH TX.
..GRAMS/GOSS.. 05/02/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BRO...
LAT...LON 27069944 27019898 26819854 26469828 26179840 26279890
26519927 26819947 27069944SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 2, 1:07 AM CDT | Mesoscale Discussion | SPC | Angelina, Austin, Bastrop, Brazos, Burleson, Chambers and 30 more | 113 min |
| May 2, 2:43 AM CDT | Mesoscale Discussion | SPC | Anderson, Angelina, Chambers, Cherokee, Grimes, Hardin and 22 more | 2 hr |
| May 2, 3:17 AM CDT | Severe Thunderstorm Watch | SPC | Angelina, Cherokee, Grimes, Hardin, Harrison, Houston and 17 more | 5 hr |
| May 2, 5:48 AM CDT | Mesoscale Discussion | SPC | Angelina, Hardin, Houston, Jasper, Liberty, Montgomery and 10 more | 87 min |
Nearby
Mesoscale Discussions in Texas, 2016Every mesoscale discussion in 2016
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.