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
680 ACUS01 KWNS 071630 SWODY1 SPC AC 071629 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Jun 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected across the central Plains especially from mid/late afternoon through evening. Damaging winds and large hail are the primary threats. ...Central Plains including Nebraska/Kansas to western Missouri... Scattered elevated thunderstorms are ongoing across southern South Dakota, and in a more isolated sense across central Nebraska. A mid-level speed max/subtle shortwave trough over Wyoming and the nearby north-central High Plains this morning will continue east-southeastward, overspreading a warm sector later today that will narrow northward across north-central Nebraska near a deepening surface low and evolving triple point. This is where surface-based thunderstorm development will become increasingly likely by mid-afternoon (circa 20z across north-central Nebraska). As surface dewpoints climb through the lower 60s F, upwards of 2000-2500 J/kg MLCAPE will reside in this corridor by peak heating. Intense storm development including supercells can initially be expected in the presence of 50+ kt effective shear, highlighted by 50-80 kt mid/high-level west-northwesterly flow. Instances of very large hail (baseball size plausible) may occur, potentially also with some tornado risk, although low-level winds/SRH will not be overly strong diurnally (roughly pre-00z). Storms are expected to merge/congeal through early evening as they progress southeastward, likely growing upscale into a well-organized MCS that will evolve across south-central/southeast Nebraska and northern Kansas, and into western/northern Missouri and southwest Iowa by late evening/overnight. Scenario will be aided by a nocturnally strengthening southwesterly low-level jet and increasingly robust warm/moist advection. A corridor of potentially widespread damaging winds and wind-driven hail is expected. ...Southwest Kansas and Texas/Oklahoma Panhandles... High-based thunderstorms are expected to develop through mid/late afternoon near a south-central High Plains surface low and adjacent surface trough/diffuse dryline. This development will be associated with a hot/deeply mixed boundary layer with temperatures in the 90s/lower 100s F. These storms will progress into a region of somewhat greater moisture and instability through early evening, with storm organization potentially aided in proximity to moderately strong northwesterly flow aloft. At least isolated severe storms can be expected, with severe-caliber wind gusts and bouts of large hail possible. ...Great Basin... A shortwave trough is readily evident in water vapor imagery near the western Nevada/California border vicinity at late morning. Ample insolation and PW values between 0.50-1.00 inch may potentially support upwards of 750-1000 J/kg MLCAPE this afternoon, especially across a broad portion of northern/central Nevada into southern Idaho and northern Utah. As thunderstorms diurnally increase in coverage and intensity, and low-level lapse rates steepen, effective shear generally 30-35 kt may allow for some sustained/organized multicells, with severe-caliber wind gusts possible with the strongest storms. ..Guyer/Gleason.. 06/07/2024 $$