Strong Storms Possible Port St. John to Vero/Ft. Pierce Late Today

See Colored Captions For Details Regarding rainfall today and types of rainfall. Showers vs. Storms, some strong due to wind gusts and frequent to excessive lightning. Big rainfall totals possible along and west of US1 toward the eastern interior of Central (Eastern Orange/Osceola Counties) as storms decay and slow in forward motion after 7:30pm

Sunset Last Night

TODAY: After what felt like a prelude to fall last night and early this morning over North Central and North Florida (Crestview got down to 62F this morning)....summer should retrograde back in to Central by early afternoon from the South and West.


Very warm to near record highs possible from Melbourne to Daytona before 3pm with highs in the mid-90Fs..although an upper 90F isn't out of the question toward the DAB airport.


FACTORS TODAY: 
1)Energy is approaching the state from the NNW out of Western GA and Eastern AL this morning. It is not forecast to quite reach Central, but could brush Daytona. Either way, it will provide lift as it approaches in the upper levels.  

2) Moisture will increase slowly in the mid levels from the south now down by Southern Brevard..it is in the process of doing so as of 11AM.  The surface front over N. Florida is washing out today so that mid level steering from the SW will be dictated more by high pressure over the SE Atlantic (which would bring Gulf moisture in from the SW) rather than from the continent. This should advect (bring in) more mid level moisture to roughly south of I-4. Instability is greatest over Central Florida running from Tampa to Cape Canaveral right now...and has been since sunrise, but covers a swath..mostly to the south..toward Vero Beach. This will mount during the day, since rain is expected later on the east side (mid-afternoon or a bit sooner).  


Interesting that, for 3 hours, latest ACTUALS are showing a band of good VGP ...in the low to mid levels..Vorticity Generation Potential. Vorticity will aid to stir things up...and then consider..in the upper levels as mentioned above some energy (vorticity) is coming down from the Deep South. Those factors, combined with coastal helicity (spin in a different plane / direction working with the vortictiy (spin) on a three dimensional cube...could add punch to thunderstorms right at the sea breeze collision as the west coast sea breeze works east during the early afternoon hours.

SEE TEXT

3) Jet stream winds are showing a bit of divergence after 7pm tonight over the North Half of the state reaching almost  toward Melbourne. This is in question though.

4) Delayed sea breeze expected north of Sebastian and should only make inland penetration to about as far west as I-95 or eastern Orange/Osceola Counties...or, only little sea breeze inland penetration until after 4pm...it could strengthen 'upriver' at that time through 6pm in Indian River and Brevard counties.


5) Lake Shadow  (mainly on the north side) and sea breeze conflicting with a gentle SW flow aloft could generate strong storms from Ft. Pierce to Vero..and possibly along the North side of Lake Okeechobee since this area is on the cusp of higher instability to the north.


These factors above should result in Eastward moving storms at 10mph; however, like always, any outflow boundary projected outward in any direction from a storm will aid in storm strength or growth elsewhere, accelerate the west coast seabreeze to the east...as well as completely scour out other areas from receiving rain. It's all in the additive timing factors and location of where these conjoin to make the strongest storms. 


I'd think at least one storm will cross to the barrier islands and out to sea by Daytona if they can get one up there..maybe a bit south of there...and off South Brevard/Ft Pierce area.  


SOUTHEAST FLORIDA: Do not believe SE Florida will see as much activity today. With an earlier sea breeze and still very unfavorable for storm formation as of 11AM. Even if it does recover quickly it might be too late for sea breeze/land breeze mergers to perform up to par, especially since the air is dry air behind the sea breeze. I was thinking SW Florida might get a good storm, but early activity over the keys and near that coast has resulted in a cirrus cap of clouds..so that chance may very well go to zero.


TUESDAY/WEDNESDAY: Active days for Storms, mostly Near and North of Lake Okeechobee. Upper level temperatures, namely at 500mb (20,000ft) are forecast to be the coldest they have been since spring time..with readings around -7.5 to -9C  as opposed to -5 or -6C as it has been all summer.  However, with mid level temperatures also cool, storms could have an early onset as soon as the earlier sea breeze develops.  With that 'theory' showers might form along the east coast sea breeze east of I-95...and drift westward...then, as the west coast sea breeze works east..collisions could produce stronger storms in areas that haven't already been worked over. This activity should be able to press back to the east. 


This scenario seemed most likely early today to occur south of Daytona On Tuesday...but on Wednesday it is up and down the entire East Coast.  Far SE Florida (South of Boynton Beach) could have an early day storm..but the remainder of the day would be worked over for further storms as the east coast sea breeze progresses further from the coast in that location..and steering will be too weak to press activity back to the coast. But honestly, I haven't waited for morning model runs to come out that extend beyond 12 hours...so these two days will have to be reassessed in the morning, based on the trends over the course of two more runs between now and then (make that 3 more). This determination was made based on two consecutive runs of the NAM and GFS.


THURSDAY/FRIDAY: Thursday looks similar to Wednesday, but the cold air aloft starts to pull out by mid-afternoon...and greater inland east coast sea breeze is anticipated. But moisture over South Central to North Florida continues to increase...and steering becomes weaker. Friday is up for grabs as of this morning, but last I saw rain chances lowered most everywhere as drier air comes across from the Western Caribbean.


TROPICS: No worries for another 10 days...but one or more storms might be in the making during this time frame that will bear very close scrutiny considering we will be entering the peak of the hurricane season...as well as the fact that storms look  to form (if they do)...at a latitude far enough south that they would either go into Mexico/Yucatan..or threaten the US SE Coastal area or Eastern Gulf Coast region.
High Pressure over Texas...has been there all spring and summer so far, so peristence says..no hurricanes to make it north of far SW Texas or west of Baton Rouge.