


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
093 ACUS11 KWNS 070456 SWOMCD SPC MCD 070456 TXZ000-070700- Mesoscale Discussion 0732 NWS Storm Prediction Center Norman OK 1156 PM CDT Tue May 06 2025 Areas affected...parts of the lower Rio Grande Valley Concerning...Severe potential...Watch possible Valid 070456Z - 070700Z Probability of Watch Issuance...40 percent SUMMARY...An isolated intense supercell, or perhaps small organizing cluster of storms, may continue to evolve west of the lower Rio Grande Valley during the next few hours, before beginning to move across the Red River toward 3-4 AM CDT. DISCUSSION...Moist upslope flow west of the Rio Grande River has contributed to the initiation of thunderstorm development along the higher terrain, around 75-80 miles southwest of Laredo. This may be aided by forcing associated with a weak a mid-level short wave trough embedded within southwesterly deep-layer mean flow on the order of 30-40 kt. At mid/upper levels this flow is strong and conducive to supercell development, particularly given inflow of seasonably moist air characterized by large CAPE, beneath steep lower/mid-tropospheric lapse rates. Although substantive near-surface drying has occurred across the Cotulla vicinity into the areas south of Laredo, with continued veering of near-surface flow from northerly to easterly, westward advection of mid 70s+ surface dew points up the lower Rio Grande Valley is likely to continue overnight. Various model output suggests that this may become supportive of at least isolated thunderstorm development propagating off the higher terrain, and across the Rio Grande River by 08-09Z. Given the environment, this could include a supercell capable of producing large hail and strong surface gusts. ..Kerr/Smith.. 05/07/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CRP...BRO... LAT...LON 28119960 27409854 26699874 26330030 26960088 28119960 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN