Day 1 Convective Outlook
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Issued: · Valid: –
Summary
Isolated severe thunderstorms capable of producing damaging winds and hail are expected this afternoon and evening across parts of the Mid-Atlantic, New England, southeast Texas, the central High Plains, and central Oregon. While damaging winds are the primary concern for much of these areas, some locations may also experience isolated large hail or a brief tornado.
Product Text
000 ACUS01 KWNS 222002 SWODY1 SPC AC 222000 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Wed Jul 22 2026 Valid 222000Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID ATLANTIC AND NEW ENGLAND...SOUTHEAST TEXAS...THE CENTRAL HIGH PLAINS AND CENTRAL OREGON.... ...SUMMARY... Isolated to widely scattered storms remain possible across the Carolinas and southern Mid-Atlantic, as well as New England this afternoon and early evening, with damaging winds as the primary concern. Isolated strong to severe wind gusts are also possible in the central High Plains, southeast Texas and central Oregon, where isolated large hail will also be possible. ...20z Update New England... A broken band of strong to occasionally severe convection remains ongoing ahead of a progressive cold front over northern and eastern New England this afternoon. Weak buoyancy, but fairly strong deep-layer shear (35-45 kt) should support isolated hail, and damaging winds with stronger clusters or supercell structures this afternoon. A brief tornado also remains possible across northern ME where low-level shear is locally stronger. The primary change this outlook cycle was to lower overall severe probabilities and remove them behind the front where the air mass has stabilized. ...Mid Atlantic and Carolinas... Farther south, the cold front has become increasingly zonally oriented and slowed as the upper trough has lifted away to the northeast. A warm and very moist environment remains in place across southeastern VA into northern NC. However, poor mid-level lapse rates and decreasing vertical shear have limited convective organization and intensity. Some renewed intensity is possible along the convectively modified boundary/differential heating axis along the NC/VA border this afternoon and evening. However, the severe threat (predominately damaging gusts) is expected to remain isolated into this evening. Severe probabilities have been lowered and adjusted to better match the main focal area for severe storms near the VA/NC border through this evening. Elsewhere, isolated severe gusts/hail remain possible over parts of the central High Plains and the southeast TX. Isolated hail is also possible over parts of central OR. Scattered storms are expected late this afternoon through the evening. No changes were made to theses areas, see the previous discussion for more information. ..Lyons.. 07/22/2026 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Jul 22 2026/ ...Northern New England this afternoon... Per water vapor imagery and morning upper air observations, a pronounced midlevel trough will progress east-northeastward from PA/NY/Saint Lawrence Valley toward New England through this afternoon. An associated surface cold front will likewise move eastward and provide a focus for thunderstorm development by early afternoon into Maine. A few cloud breaks developing from west-to-east through the afternoon will allow surface temperatures to warm into the 70s with boundary-layer dewpoints in the mid 60s, resulting in MLCAPE in the 1000-1500 J/kg range. Deep-layer, south-southwesterly shear will be sufficient for a mix of clusters and supercells with a primary threat for occasional wind damage. ...Mid-Atlantic this afternoon/evening... A pre-frontal band of convection is ongoing across southern VA, with a narrow zone of stronger surface heating/destabilization to the north of the thicker clouds from northern VA into MD/DE in advance of a cold front moving across PA. The southern fringe of the stronger (35-50 kt) midlevel flow extends to near the VA/NC border on the south side of the thicker cloud band. The ongoing convection is likely persist through the afternoon while spreading slowly southward. Midlevel lapse rates will remain poor, but deep-layer vertical shear will be sufficient for embedded/organized storms with occasional wind damage. Low-level shear will be marginally favorable for rotating storms and perhaps an isolated tornado. ...Southeast TX late this afternoon through late evening... Strong surface heating is underway with a general confluence zone near the TX/LA border well to the west of highly-sheared Tropical Storm Bertha. As Bertha continues westward, this confluence zone should support thunderstorm development into southeast TX late this afternoon. Steering flow from the northeast at ~35 kt will favor storm clusters moving southwestward into a hot, deeply mixed boundary layer where buoyancy will be sufficient to maintain the storm clusters into late evening. A few strong-severe outflow gusts will be the main threats. ...Northeast CO and vicinity this afternoon/evening... Low-level upslope flow on the cool side of a surface front, combined with weak perturbations rotating around the northwest periphery of the southern Plains midlevel high, will support afternoon thunderstorm development over the foothills. The storms will spread east-southeastward onto the plains, with a tendency for clustering with the potential for isolated severe outflow gusts. ...OR this afternoon/evening... Along the northwest edge of the monsoonal moisture plume, a midlevel shortwave trough will move northward from northern CA into OR. Weak forcing for ascent combined with daytime heating over the higher terrain will support scattered thunderstorms later this afternoon/evening from the Cascades into central OR. An environment with MLCAPE of 500-1000 J/kg, steepening low-level lapse rates and effective bulk shear near 25 kt will support isolated strong outflow gusts and marginally severe hail. $$