Plaincast

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Warm and humid conditions will continue through the week as a WSW wind flow prevails. Overnight lows will continue to be warm, in excess of 80 degrees along the coast.

Scattered to numerous thunderstorms will continue each day. Heavy rainfall is the primary concern, particularly in urbanized areas.

Update

Quieter evening underway following active day with periods of showers and storms affecting much of the area. The Tampa Bay area down through the Bradenton area and western Manatee County, along with areas north of I-4 across the Nature Coast were the primary beneficiaries of today's rainfall. Half-inch plus totals were common across those areas, however many locations received 1-2 inches, with localized totals of 3-5 inches across parts of Hernando, Sumter, Citrus and Levy counties. Activity has since diminished, and conditions are likely to remain mostly quiet until redevelopment across the nearshore waters and coastal locations later tonight through Tuesday morning. Given that the general pattern remains the same, with abundant moisture remaining over the area, Tuesday is likely to play out similar to today, with showers and storms gradually expanding in coverage from coastal toward interior areas through the afternoon. However, hi-res expected rainfall PMM output indicate that highest totals over the next 24 hrs are likely to remain in closer proximity to the coast than interior locations, and generally across WC/SWFL areas. Moist and humid conditions will translate to overnight lows only falling into the mid 70s to around 80 degrees, while afternoon highs range from the upper 80s along the immediate coast to the mid 90s inland. Nature Coast locations away from the more widespread convection and cloud cover, at least earlier in the day, may once again require heat advisory products.

Discussion

The subtropical ridge axis remains suppressed to the SE of the Florida peninsula as a weak frontal boundary and surface low slowly meanders southward off the SE coast. This is due to an upper-level ridge over the WEST CONUS and an upper-level trough over the E CONUS. In response, a westerly flow prevails across Florida, with deep tropical moisture streaming into the region. The 12Z sounding showed a precipitable water of 2.04 inches this morning. Climatologically, this comes in near the 75th percentile for the day, suggesting there is more moisture present than a "typical" day.

Indeed, this has played out, with a multicellular cluster continuing to slowly drift southward along the Florida west coast. Additional shower and thunderstorm activity has popped up across the interior. New thunderstorms have also redeveloped across the Nature Coast in areas that already saw thunderstorms this morning, thanks to daytime heating and an opportunity to clear out for awhile. New thunderstorms are expected to continue developing through sunset tonight.

Over the course of the next week, the pattern remains very static. An upper-level ridge remains dominant in the west, while a trough remains situated over the E CONUS. Really, the only element of note is that the winds shift more to WSW and increase later in the week. This is due to slight shift in the trough axis, and thus a slight southward shift for the ridge, allowing the surface front to slowly meander farther south later this week. High precipitable water remain through the period, leading to scattered to numerous showers and thunderstorms each day.

The compounding influence of multiple days of heavy rainfall favor a greater potential for localized flooding as the week progresses. However, antecedent conditions still allow for quite a bit of rain to fall before major problems occur. Thus, the primary threat - for this week at least - will remain in more urban areas.

With this flow in place, it will remain very warm and humid. Overnight lows along the coast are not expected to dip below 80 degrees. For these areas, the lowest temperatures for the day may in fact occur during daytime hours as thunderstorms develop and move through. In areas that don't see rain, this combo will favor heat indices approaching 108 degrees by the afternoon. This is especially true across the northern Nature Coast, where heat advisories may continue to be needed for days to come.

The next chance for this pattern to break is next week as ridging slowly builds back in. In response to this change, a more southerly then perhaps ESE flow returns. This favors a more typical summertime pattern returning early next week with mostly sunny mornings and afternoon and evening showers and thunderstorms.