


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
212 ACUS01 KWNS 130555 SWODY1 SPC AC 130553 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CDT Sun Jul 13 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL/EASTERN AND SOUTHWEST STATES... ...SUMMARY... Isolated severe thunderstorms are possible today through early tonight in the Upper Midwest, Mid-Atlantic/Northeast, Southwest, south-central Texas to the Lower Ohio Valley, and Florida. ...Upper Midwest... In the wake of a 500-mb trough passage this morning, a strong 500-mb jetlet will shift across the southern Prairie Provinces. Guidance consensus indicates a low-amplitude 700-mb trough should shift southeast ahead of the aforementioned jetlet in the eastern Dakotas to western MN by late afternoon. This should aid in strengthening convergence along a progressive surface trough approaching northeast MN to the Mid-MO Valley. The northwest flow setup will yield favorable hodograph structure for potential discrete supercells and large hail production. But modest mid-level lapse rates and a confined weak to moderate buoyancy plume, largely driven by evapotranspiration ahead of the front, should modulate overall intensity/coverage. Isolated large hail/severe gusts from a few widely spaced supercells seem plausible from late afternoon to dusk. ...Mid-Atlantic/Northeast... Scattered to numerous storms are expected this afternoon within a persistent high PW airmass across the East. Convection from PA southward will remain disorganized amid weak to minimal shear with southern extent into VA/NC. Modest mid-level southwesterlies across NY, owing to peripheral influence of the ON/Upper Great Lakes trough, may aid in weak multicell clustering here. Erratic, mainly pulse convection is anticipated with locally strong gusts. ...Southwest... As a mid-level anticyclone becomes centered over the southern Great Basin, modest northerlies will dominate across northern NM turning to easterlies over southeast AZ. Widespread storms are expected to develop off the higher terrain and slowly progress south to west from mid-afternoon to mid-evening. With a gradient in buoyancy from northwest to southeast, larger over the southern High Plains, isolated severe hail will be possible over NM. Otherwise, isolated severe gusts should be the primary threat into southeast AZ. ...South-central TX to the Lower OH Valley... A nearly-stationary MCS is expected to be ongoing at 12Z across a portion of south-central TX with a primary threat of flash flooding (see WPC EROs/MPDs for details). Scattered convection should also be ongoing north-northeast into parts of MO. Multiple MCVs within both regimes will likely drift east within a low-amplitude mid-level trough. A belt of enhanced 700-mb southwesterlies ahead of these features may overlap various large-scale outflows. This could support an uptick in isolated damaging winds surrounding peak boundary-layer heating, mainly from midday to dusk. ...FL... With the mid-level anticyclone becoming centered along the central Gulf Coast, weak northerly flow will dominate much of the state. 00Z HREF indicates a pronounced signal for scattered storms along the north FL/south GA border through the central/eastern FL Peninsula. Amid 2000-3000 J/kg MLCAPE and high PW values yielding melting small hail, localized marginal severe gusts in wet microbursts will be possible from mid-afternoon to early evening. ..Grams/Thornton.. 07/13/2025 $$