SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sun Apr 23 2023 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY ACROSS PARTS OF THE FLORIDA PENINSULA... ...SUMMARY... Strong thunderstorms may impact interior and Atlantic coastal areas of the Florida Peninsula Monday, and pose at least some risk for severe weather. ...Synopsis... Within a persistent split flow across the mid-latitude eastern Pacific into Atlantic, one blocking high, centered near Newfoundland and Labrador, appears likely to remain prominent through this period and beyond. This high will be flanked to its southeast by a low over the mid-latitude Atlantic, and to its southwest by a low which is forecast to begin redeveloping southeast of the Upper Midwest through the lower Great Lakes region. Upstream, within one increasingly amplified branch of westerlies, models suggest that mid-level ridging will build across southern portions of the eastern mid-latitude Pacific, toward U.S. Pacific coastal areas, while a downstream short wave perturbation digs into the Great Basin with a developing embedded mid-level low. In advance of the latter feature, a moistening southerly return flow likely will commence across the lower Rio Grande Valley into the southern Great Plains. However, relatively cool surface-based air, associated surface high pressure encompassing most areas east of the high plains, likely will be maintained, while inhibition increases aloft, associated with the northward and eastward advection of elevated mixed-layer air. Across the Gulf Coast/Gulf of Mexico vicinity, models indicate considerable strengthening of westerly mid/upper flow through the period. As this occurs, it appears that a perturbation emerging from the lower Rio Grande Valley today will overspread the Florida Peninsula during the day Monday. ...Florida... To the south of a reinforcing, but stalling and weakening surface front, models indicate that low-level moisture will be maintained or begin to increase across much of the southern and central peninsula during the day Monday. It appears that this will include mid/upper 60s surface dew points on easterly near-surface flow, particularly across central and southern Atlantic coastal into interior areas, beneath relatively cool mid-level temperatures. With insolation, this may contribute to moderate mixed-layer CAPE on the order of 1000-2000+ J/kg, prior to the approach of the mid-level short wave trough Monday afternoon. Aided by the strengthening large-scale forcing for ascent, it appears that this destabilization may yield increasingly widespread thunderstorm development across interior into Atlantic coastal areas through late afternoon. Beneath the moderate to strong mid/upper flow, deep-layer shear may become conducive for some of this convection to organize, with supercell structures also possible, which may pose a risk for severe wind and hail before convection weakens by Monday evening. ..Kerr.. 04/23/2023
