(Image: Circumscribed Arc photo'd this morning with bird on perch. These form when the sun is approximately 29 degrees above the horizon with columnar ice crystals present and all oriented in the same way.)
SYNOPSIS: Ridge of high pressure extends generally from East Texas and across the Northern Gulf...in the mid levels it is located directly over the Space Center where 11am sounding showed winds at 850mb to be 0, that's ZERO as in dead calm. Winds at all other levels are around 5 kts or less up to almost 20,000ft. Moisture wise, PWAT has risen a bit since 6am to 1.81". There is a bit of an inversion near 2500ft...with no moisture consolidation noted other than right at this level. Just enough to form showers which as they grow in height encounter drier air. A little more moisture resides south of Lake Okeechobee across South Florida where winds are more defined by shower motion from East to West. Further north from Vero north through Central Florida shower motion is essentially non-existent as one would expect with the winds described above. Temperatures aloft have warmed to those reminiscent of most of the second 1/2 of the summer, with 700mb at 10C and 500 at -4C.
PENINSULA WIDE: In satellite animation and radar trends, appears an axis of greater mid level moisture as noted by a greater cumulus field extending roughly from Ormond Beach on the east coast to must north of Brooksville toward the West Coast about 40 miles wide either side of this axis. This axis seems to be moving little. Showers are going up along I-95 near MLB (where they reported a shower last hour as can be seen from my porch), . Probably of greater meteorological interest is an east coast sea breeze boundary from near Ft Lauderdale to just south to west of Miami. It made a good forward surge toward the NW initially but seems to have slowed down over the Everglades. The heaviest showers, one of which is producing lightning, is located NW of Miami over the Everglades in no-man's land. Aloft, cirrus clouds are streaming over the the Gulf Coast Ridge and washing across North and Central Florida but have thinned significantly since earlier this morning. These clouds helped in forming the circumscribed arc shown in this post which last over an hour.
TODAY: Warmer temperatures aloft, moist air, and light winds aloft and at the surface with no triggers make for a generic forecast on my part which will lean on the dry side on the broad brush. Almost all shower and storm development will rely initially on sea and lake breeze boundaries, after which other showers can initiate as a result of outflow from collapsing ones. With such widely scattered shower amounts anticipated due to warmer air aloft it might be hard for boundary interactions between adjacent showers to develop. East and West coast sea breezes will begin (other than the one over SE Florida) by 2pm but move very little from either coast. Thus, we might not even see a sea breeze collision today over the interior. If there is one, it would most likely be around Lake Okeechobee on the west side. Toward Central Florida is would occur around sunset after heating begins to be lost. Expect greatest shower coverage overall to be during the 6-8pm hours, with the strongest of which to be along the W-SW Florida Coast between that and Lake Okeechobee. Another hot spot could be over Polk County and perhaps western Osceola County as expecting the West Coast sea breeze to be a bit more active over the South Half of the state. If this proves to be so, this area would be wet for quite a while as activity lingers.
TOMORROW: Very similar to today. Not expecting cirrus over head tomorrow morning, so day time heating might get things started roughly an hour earlier. Winds aloft should become somewhat more determined by the ridge axis consolidating into more of a well defined circulation near N. Louisiana, as such winds aloft would become measurable from the NW. Trough moving off the mid-Atlantic today with a surface boundary across Central Georgia -Alabama will get no further south due to the ridge across the N. Gulf which will hold fast. However, as the trough exits the U.S. East Coast and gets further from the continental ridge it could make a little bit of a dig to allow a light land breeze to form by morning...as was mentioned in yesterday's post from near West Palm to Jax. Mid level winds may also become W-NW around the ridge across Central Florida..but all these winds will be only 10mph aloft or less and have little overall affect on storm motions other than to keep activity more focused to the east side of the state but west of the sea breeze boundary which will develop around 1-2pm. Perhaps a better chance of activity over N. Brevard tomorrow over the Cape toward Titusville and Port St John early afternoon, but also development possible along the intracoastal for a brief time before and during the initial phases of the sea breeze. Speaking of which, it should make less inland progress tomorrow than today and not expecting a collision of west meets east once again.
Further south. An entirely different ball of wax. Generally the region from Ft Lauderdale to Sarasota is under a different flow regime entirely with activity focused more toward the West side of the state during the afternoon and evenings...and on the east side early morning to early afternoon.
SATURDAY: Little change in the overall pattern with a greater influence of mid-level winds to mount moisture up in the late afternoon through mid-evening hours along the SW FL Coast from Bradenton to Naples and west of Lake Okeechobee. Other areas will receive a wide scattering of showers and perhaps an isolated thunder, more likely over South Florida but not discounting Central Florida.
TROPICS: Igor the EyeSore. Won't do much for a while as it is currently being sheered by upper level winds. But don't be fooled. This system could still end up as a large and strong Hurricane, but as mentioned yesterday is most likely going to remain a thrill for only the satellite imagery lover. Point blank though, despite what models currently depict, it's way too early to now with any degree of confidence whatsoever at this point that it will definitely be a fish storm. If it circumvents the next trough coming off the U.S. East Coast next week it would mean shear panic for somewhere on the U.S. East Coast. Eyes might do better to focus toward the Caribbean where development of an area of disturbed weather appears to have the upper development hand. This area should track toward the Yucatan and into the Bay of Campeche...but bears watching. Where ever this thing goes, somebody is going to be affected. Can't say that about Eyesore as it stands now until next week...but first it needs to get organized...for now, it's just that.