Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 415

April 18, 20166 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2016, 10:08 PM CDT for 6 counties in Texas. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Apr 18, 2016, 10:08 PM CDT (03:08 UTC)
Expired
Apr 18, 2016, 11:15 PM CDT
In force
67 min
Issued by
the Storm Prediction Center

Counties Cameron County, TX, Hidalgo County, TX, Jim Hogg County, TX, Starr County, TX, Willacy County, TX, Zapata County, TX

The radar

The Brownsville radar (KBRO), 115 km from the middle of the area, began a volume at 03:09 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, 3.1 hours before the alert went out and 118 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.

Skew-T log-pSkew-T log-p diagram, Brownsville Intl, TX at 00:00Z on 2016-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1260 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brownsville Intl, TX at 00:00Z on 2016-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1260 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
947 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
308 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.3

Open this sounding in Storm Lab

The text

As transmitted.

380 
ACUS11 KWNS 190308
SWOMCD
SPC MCD 190308 
TXZ000-190415-

MESOSCALE DISCUSSION 0415
NWS STORM PREDICTION CENTER NORMAN OK
1008 PM CDT MON APR 18 2016

AREAS AFFECTED...PORTIONS DEEP S TX...LOWER RIO GRANDE VALLEY.

CONCERNING...SEVERE THUNDERSTORM WATCH 97...

VALID 190308Z - 190415Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 97
CONTINUES.

SUMMARY...REMAINDER WW MAY BE ALLOWED TO EXPIRE AS
SCHEDULED...EXCEPT WHERE CANCELED EARLY LOCALLY.

DISCUSSION...AGGREGATED COLD POOL FROM EARLIER CONVECTION FARTHER
N...REINFORCED BY PRIOR ACTIVITY OVER THIS REGION...HAS STABILIZED
LOW-LEVEL LAPSE RATES CONSIDERABLY.  THIS CONTRIBUTES TO MLCINH
100-250 J/KG IN MODIFIED RAOBS AND FCST SOUNDINGS...OVER MUCH OF
AREA N OF RIO GRANDE.  ELEVATED WAA MAY CONTINUE TO SUPPORT WIDELY
SCATTERED TSTMS N OF OUTFLOW BOUNDARY THAT HAS SURGED WELL SWWD INTO
MEX...AND ISOLATED/BRIEF HAIL NEAR SVR LIMITS CANNOT BE RULED OUT
DEFINITIVELY INVOF RIO GRANDE...ESPECIALLY NW MFE WHERE POCKETS OF
FAVORABLE MIDLEVEL LAPSE RATES MAY LINGER ABOVE COLD POOL. 
HOWEVER...PRIND ORGANIZED SVR THREAT HAS WANED SUFFICIENTLY THAT WW
IS NO LONGER NEEDED PAST NOMINAL 04Z EXPIRATION.

..EDWARDS.. 04/19/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CRP...BRO...

LAT...LON   25949710 25939732 25839735 25859753 26019763 26049778
            26069798 26059814 26229846 26229864 26369878 26419909
            26509910 26869928 26919938 26989937 27039944 27229943
            27329951 27569943 27459926 26989862 26759856 26549833
            26549784 26659746 26589726 26279717 25949710

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 19, 12:48 PM CDTMesoscale DiscussionSPCBaylor, Briscoe, Childress, Cottle, Crosby, Dickens and 14 more2 hr
Apr 19, 1:15 PM CDTMesoscale DiscussionSPCAndrews, Borden, Crane, Crockett, Dawson, Ector and 13 more3 hr
Apr 19, 3:48 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Cottle, Dickens, Foard and 7 more2 hr
Apr 19, 6:11 PM CDTMesoscale DiscussionSPCCallahan, Coke, Coleman, Concho, Crane, Crockett and 17 more94 min
Apr 19, 6:32 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Cooke, Denton, Dickens and 23 more2 hr

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.