SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Jun 09 2025 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST NEW MEXICO AND FAR WEST/SOUTHWEST TEXAS... ...SUMMARY... The most likely corridor for severe storms on Tuesday, primarily in the form of large hail, is across far southeast New Mexico and the Texas Trans-Pecos during the late afternoon through early evening. Isolated severe thunderstorms are also possible on Tuesday into Tuesday evening along parts of the East Coast, from southeast New Mexico to south Louisiana, and in parts of the Northwest. ...Southeast NM and Far West/Southwest TX... Strong heating is anticipated over the region Tuesday along the western periphery of seasonably rich low-level moisture in vicinity of a front and weak surface wave. Combined with steep mid-level lapse rates, large buoyancy with MLCAPE of 2500-3000 J/kg is expected. An upstream low-amplitude shortwave trough near/north of the International Border will approach the region during the afternoon. In combination with diurnal orographic ascent, scattered to eventually widespread thunderstorm development is anticipated. A narrow belt of moderate mid-level westerlies, centered on the Trans-Pecos, should support a few supercells in the late afternoon. Large hail will likely be the primary hazard. Some degree of upscale growth may occur by evening toward the Rio Grande vicinity, with at least some severe hail/wind persisting east-southeastward. ...South-central TX to south LA... It still seems that a loosely-organized MCS may be ongoing in central TX at 12Z Tuesday. Within a weakly forced and nebulous large-scale pattern, guidance has a fair amount of spread with subsequent evolution through the day Tuesday. It is plausible that intensification may occur by midday along the residual outflow, along with downstream development towards a quasi-stationary front into LA. Deep-layer shear will be modest, especially outside of any localized enhancement near the remnant MCV. Confidence remains too low to warrant greater than level 1-MRGL risk probabilities at this time, but isolated severe wind/hail remains possible. ...Mid/South Atlantic Coast... A broad mid/upper trough will extend from eastern Ontario to the OH/TN Valleys at 12Z Tuesday. The southern extent of this trough will gradually dampen through the period with slowly rising mid-level heights. A broad rain swath with embedded thunderstorms is expected to be ongoing from the Mid-Atlantic northward, where stronger deep-layer flow will exist. Diurnal destabilization appears quite limited and locally strong gusts might occur along the southern periphery of this morning activity. Isolated thunderstorms are possible into the afternoon along parts of the South Atlantic Coastal Plain. Despite ample boundary-layer moisture/heating, poor mid-level lapse rates will limit updraft intensity and overall convective coverage. Locally strong gusts capable of wind damage will be possible with any sustained storms. Coverage is likely to be less compared to recent days. ...Northwest and Northern Rockies... Low-amplitude mid/upper ridging will break down as a shortwave trough progresses into northern CA/southwest OR by 12Z Wednesday. As this occurs, mid to upper-level flow will become more westerly with moderate speed shear across the northern Rockies. Despite weak buoyancy, scattered high-based thunderstorms are expected. The strongest of these may attain low-end supercell structure from western to south-central MT during the late afternoon to early evening. Across southern OR, strengthening large-scale ascent with approach of the shortwave trough should support scattered late afternoon to evening storms. High-based multicells to a couple brief supercells are possible. Isolated, marginally severe wind/hail events may occur in both regimes. ..Guyer.. 06/09/2025