Aloft, a shortwave trough is digging into the Gulf of Mexico and is expected to progress west today. At the surface, the SPC notes a low west-southwest of Tampa that is expected to move east-northesast. Infrared satellite imagery hints at a sharp boundary with cooler cloudtops. Level II state radar shows showers over central Florida with a few potent cells entering northern Brevard County and another entering northern Manatee County. In fact, NWS-MLB has issued a tornado warning for northern Brevard and southeastern Orange counties until 11:45 AM EST.
There are a few factors that could enhance the severe weather threat this afternoon in south Florida...
- Approaching shortwave trough could enhance wind shear to allow for rotating thunderstorms. 12Z soundings from Miami already indicates some shear and things could enhance later today.
- Satellite imagery shows some clearing north of Miami and south of Tampa Bay. Daytime heating could help destabilize the atmosphere later today.
However, the SPC notes that large-scale rising air will not be too great, but there is a shot of long-lived updrafts locally. The SPC has just issued a tornado watch for Broward, Miami-Dade, Palm Beach, Monroe counties, and adjacent coastal waters (out to 20 NM) until 7 PM EST. The highest severe risk are strong winds and tornadoes. Based on a couple of storms I've seen this morning, bow echoes seem to be the culprit and the SPC is hinting at that continuing.
Keep any eye to the sky in south Florida. I'll do best to keep tabs on my Twitter account as the day wears on.