|INSTABILITY INDEX: Convective Available Potential Energy and the surface based Lifted Index.|
Note the high CAPE values and low LIs over Volusia and North Brevard County at Noon
Theoretically this would mean big thunder today...but...?
TODAY: A weakening frontal boundary is moving down the Florida peninsula early this afternoon from the NNW. Ahead of the front the air mass over Eastern Portions of North Central Florida is growing increasingly unstable as noted in the image above. Also note the dry pocket over KSC which was previously the most moist area.
RECAP OF THE MORNING: During the mid morning hours the air mass over Florida was very moist at the low levels; however, during the course of the past 2 hours the dewpoints have been steadily dropping off from near 70F to the mid-60Fs if not less, This line is currently moving into the unstable environment as I write...but the air is also drier, mostly WEST of Volusia and thus limiting both the intensity and coverage of rainfall. This is not expected to change during the course of the afternoon. However, some 70F dew points still reside over Volusia and into North Brevard. There is a dry pocket very close to Port Canaveral, but that seems to be on the eroding trend as the boundary approaches and moisture convergence is increased.
FORECAST PRELUDE: In the absence of any low level upward forcing mechanisms or stronger upper level energy streaks other than what is supporting the line at this time...believe the best location for lightning today will be over Volusia County and south toward Port Canaveral as a last gasp tail end charlie of non-descript worthiness nature.
There is an odd moisture divergence circulation
Other than the frontal boundary, and in the absence of a sea breeze boundary..what we have is what we got. At least as of this hour.
FORECAST: The front is forecast to gradually slow in its southward progression today and eventually reach my house...that's what the RUC and NAM models told me. Beyond Melbourne the front is non-existent losing all identity at the surface level...thus..the upward forcing mechanism is shut down..and likewise, the rain other than lingering pockets where ever operation 'breakdown' commences. This could happen over Central Brevard.
Showers and very isolated thunder will continue south while pusing east through Volusia today. Watch out for renegade lightning strikes! Precipitation will not be excessive no matter how one slices the pie...but lightning could still occur from a select storm cell or two as the boundary proceeds to South of the Border (of Volusia/Brevard).
However, it is highly uncertain in regards to the activity in Volusia. I seem to see a few ingredients at play that could bring a respectable lightning generator into Volusia..which would be in the 2:30-4:00pm time frame. An additional enhanced area could from as well further south from Titusville to the Port. Believe these will be at their strongest once they reach the higher dew point air along the West Border of Volusia as the move east...as well as with N. Brevard after 5-6pm time frame.
Strong wind gusts in the 40-50mph range seem possible..given the winds and cold air aloft, but they will first have to reach great heights of which I have yet to see on radar imagery. The afternoon is still young though...so be advised...watch the western horizon for towering clouds of convective nature.
IN SHORT: The best chances for lightning today are all of North Central Florida ...including a part of the Orlando area to Cocoa Beach, but the strongest of activity will be anywhere over Volusia and possibly as an outlier South of the Border toward Titusville/Cape Canaveral at the North Central/South Central line...The Great Divide I have referred to how many times now in the past few months?! My goodness.
The most likely areas to receive a potentially stronger storm are near Daytona Beach and Titusville/Cape Canaveral as an outlier considering a secondary impulse is implied by model guidance to cross that area sometime later in the afternoon as it rides along the near stationary frontal boundary by that time. It would be interesting if this were to occur, because that might allow the sea breeze to develop. I am also interested to see what will happen when the more southern impulse reaches the coast of Brevard where that seeming circulation is residing and helicities right at the coast have been forecast to increase. Could be nothing at all..might, not even rain for that matter..but it seems set in stone that it will at least rain near the Port as well based on the past 3 model runs of 3 separate models. Remembering my post of yesterday where I questioned that area. However, none of the high values are portrayed as they were yesterday..sort of a weaker version of possibly nothing anyway. Maybe you can tell that I WANT A STORM! Near DAB seems a given.
NEXT RAIN CHANCE: Perhaps Friday and / or Saturday. The GFS is all over the place with these two days. But note...today's system is an introduction to a new season for all of North Central to South Florida with more systems to either directly impact or graze the region through the end of the month..PERHAPS.
Either that, or we'll be entering the dreaded dry spell before Thunderstorm season begins. That too, has varied on a 12 hourly basis. But I'm opting that the last GFS run was a fluke' bustcast'.
The front is expect to stationarialize (new word)...over or near the 520 Cswy and wash out. with rains not expected much further south than that location on the east coast or anywhere else over the state to the south where mid level warming is capping the region.