Severe Storm Risk - Orlando International Airport, FL

There is a Marginal Severe Storm Risk for your location. Continue reading for today's outlook from the National Weather Service's Storm Prediction Center. -------------------- National Severe Storm Outlook THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF THE MID SOUTH INTO LOWER OHIO VALLEY AND ACROSS PARTS OF THE EASTERN GULF COAST STATES SUMMARY Widespread strong to severe wind gusts may accompany a developing squall line across and east of the middle into lower Mississippi Valley late this afternoon into this evening. A couple of strong tornadoes are also possible within and just ahead of this line across parts of the lower Ohio Valley into Mid South, with a couple of strong tornadic supercells also possible across parts of the Florida Panhandle and southeastern Alabama into adjacent Georgia late tonight. Discussion To the north of an expanding blocking mid-level high, centered off the southern California coast, models indicate that large-scale ridging will continue to build inland of the British Columbia/U.S. Pacific coast, through the Canadian Rockies and U.S. Intermountain West during this period. Downstream, a significant short wave trough is forecast to continue amplifying southeastward across the Great Plains and Mississippi Valley, preceded by building ridging near and east of the Atlantic Seaboard. Downstream of the digging short wave trough, a broad and deep cyclone has already formed to the east of the Colorado Rockies, with a plume of warm elevated mixed-layer air overspreading the central and southern Great Plains toward the lower Mississippi Valley. The center of the cyclone is forecast to redevelop east-northeast into the St. Joseph MO vicinity by daybreak, before continuing to deepen while migrating northeastward toward lower Michigan today through tonight. It appears that the northeastern periphery of the elevated mixed-layer plume will spread across the lower Missouri Valley before becoming suppressed southeastward. In the wake of a preceding surface cyclone and associated cold frontal passage, Gulf boundary-layer moistening and inland return flow remain limited at this time. Although it should improve some, aside from a narrow corridor of better boundary-layer moisture return across the southeastern Great Plains toward the lower Ohio Valley, and broader corridors across the southern through middle Atlantic Seaboard, as well as across the eastern Gulf Coast vicinity by late tonight, warm sector dew points may not exceed lower/mid 50s F. This may prove a limiting factor to the overall severe threat. Nevertheless, guidance continues to indicate the development of a fairly extensive squall line along much of the length of a cold front advancing across and east of the Mississippi Valley toward the Appalachians late this afternoon through tonight. Lower Mississippi Valley into Great Lakes Latest model output suggests that the stronger 850 mb jet core may tend to shift ahead of the deepening surface cyclone, north of the Ohio Valley into and through the lower Great Lakes region during the afternoon. However, 40-50+ kt southerly flow may tend to trail back ahead of the cold front to the southwest, at least as far as the Mid South vicinity through late afternoon, as a narrow corridor of better boundary-layer moisture return (characterized by lower 60s F surface dew points) surges across northeastern Arkansas and southeastern Missouri into southern Illinois, western Kentucky and Tennessee. North-northeast and east of this vicinity, toward the Great Lakes and upper Ohio Valley, the narrow corridor of better pre-frontal moisture is likely to be more modest and supportive of rather modest to weak CAPE. And there is concern that deeper boundary-layer warming and mixing in the drier pre-convective environment may actually be more efficient at mixing down stronger momentum to the surface than the thunderstorm activity. However, based on the latest forecast soundings, there does still appear potential for widespread potentially damaging wind gusts at least approaching or exceeding 50 kts, with an evolving pre-frontal squall line as it spreads across and east of the middle to lower Mississippi Valley vicinity. Gusts exceeding 65 kts, and potential for tornadoes, may tend to be confined to meso-vortices evolving along the leading edge of the convective outflow, particularly within the more moist environment across the lower Ohio Valley into Mid South. There may also be a late afternoon into early evening window of opportunity, across this same corridor, for either initially discrete supercell development or discrete supercell development just ahead of the evolving eastward advancing line. If this occurs, there will probably be at least somewhat greater potential for strong tornadoes. However, this remains unclear, particularly given the limited breadth of the moist sector, and the tendency for it to be rather quickly overtaken by the cold front. Eastern Gulf Coast States Models continue to indicate a separate area of better low-level moisture return across the eastern Gulf coast, which may include surface dew points increasing through the lower/mid 60s across the western Florida Panhandle, southeastern Alabama and adjacent Georgia by late tonight. It appears that this will support a corridor of boundary-layer destabilization characterized by CAPE in excess of 1000 J/kg. Coincident with enlarging, clockwise curved low-level hodographs beneath 40-45 kt southwesterly 850 mb flow overspreading the region, and in the presence of sufficient deep-layer shear, there appears potential for the evolution of longer-lived supercells which could become capable of producing strong tornadoes.