|May 22, 2017 1630 UTC Day 1 Convective Outlook|
|Updated: Mon May 22 16:25:26 UTC 2017 ( | )|
|Probabilistic to Categorical Outlook Conversion Table|
|Probabilistic Tornado Graphic|
|Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
|Probabilistic Damaging Wind Graphic|
|Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
|Probabilistic Large Hail Graphic|
|Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
SPC AC 221625 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 1125 AM CDT Mon May 22 2017 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NM AND WEST/WEST-CENTRAL TX... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL/SOUTHERN HIGH PLAINS TO THE UPPER MIDWEST... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE GULF COAST TO SOUTHEAST VA... ...SUMMARY... Severe thunderstorms will be possible this afternoon and evening from parts of eastern New Mexico into west Texas. Other strong to briefly severe storms may occur across the western/central Gulf Coast region extending Northeastward into Southeastern Virginia, as well as the central Plains and Upper Midwest. ...Synopsis... A longwave trough will continue to evolve over the CONUS to the east of the Rockies, with multiple embedded low-amplitude disturbances crossing the Plains and Gulf Coast into the Southeast States through tonight. ...Southern High Plains... Beneath a plume of steep mid-level lapse rates noted in 12Z observed soundings, weak low-level upslope trajectories will maintain modest boundary layer moisture across west TX into eastern NM today. This scenario should result in as much as 1000-1500 J/kg of MLCAPE by peak heating especially across east-central/southeast NM into west/southern TX including the TX south Plains and Permian Basin vicinities. Storms are likely to initially develop and intensify through early/mid-afternoon across eastern NM. In the presence of strengthening west-northwesterly mid/high-level winds, more than adequate buoyancy and vertical shear will exist for supercells capable of large hail. These storms are likely to spread east/southeastward into west/southwest TX by late afternoon, with a continued large hail risk and an increasing potential for severe-caliber wind gusts as storm mergers occur. These storms may reach parts of the Edwards Plateau and Low Rolling Plains by late evening. ...Western/central Gulf Coast region to Southeast VA... A cluster of persistent eastward-moving thunderstorms exist along and off the middle TX coast to coastal LA early this morning, with other showers and a few thunderstorms noted across other parts of east TX to the lower MS River Valley. Focused generally near a west/southwest to east/northeast-oriented frontal boundary (modulated by outflow), this convection appears to be aided by a weak southern-stream disturbance. While deep-layer/low-level winds are forecast to gradually strengthen through the afternoon and evening atop the frontal corridor, the widespread nature of near-coastal convection contributes to uncertainty regarding the degree of destabilization in inland areas. Even so, some potential for locally damaging winds, marginally severe hail and possibly a brief tornado (near-coastal areas) will exist today. Should greater inland destabilization become more apparent, areas such as southern LA/far southern MS could warrant a Slight Risk upgrade. Farther east, other more isolated strong to locally severe thunderstorms could occur this afternoon and evening across other parts of the Southeast States into the Carolinas. A few isolated severe storms may develop in North Carolina through Southeastern Virginia associated with a slow moving MCV. ...Central Plains and Upper Midwest... Low-level moisture will be limited in advance of a pre-frontal trough and weak southeastward-moving front today, although diurnally steepening lapse rates and modest moisture will yield weak buoyancy mainly across far southeast SD and east-central NE into IA/southern MN. Isolated to widely scattered thunderstorm development is expected this afternoon. While updraft intensities will be tempered by weak overall buoyancy, strong mid-level winds across the area could contribute to a few stronger storms capable of strong gusty winds and possibly some marginally severe hail this afternoon into evening. Farther west, other southeastward-moving high-based storms are expected across the central High Plains this afternoon/evening with some potential for severe-caliber winds and perhaps some hail. ..15_ows.. 05/22/2017 NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z