"But seeing they could not See; hearing they could not Hear"
“The views expressed herein are those of the author and do not necessarily represent those of the National Weather Service or affiliate/related organizations. Please consult .gov sites for official information”

"From its chamber comes the whirlwind, and cold from the scattering winds." - Job 37:9.

"The wind blows to the south and turns to the north; round and round it goes, ever returning on its course".

Saturday, August 6, 2011

Headlines Abound: Emily's Memory, Heat Indices, and Lightning

11:30AM Visible Satellite Image Courtesy of Yellow arrows show upper level outflow with the exception of the one in the NE Corner showing a thunderstorm Outflow Boundary. The orange line is the general location of the low to mid-level trough axis associated with what was Emily. This trough, in monitoring since 7AM, is drifting North and maybe even to the NNE.

TODAY: Very tricky transition day!! The transition consists of the remnants of Emily pulling out to the N-NNE and eventually NE-ENE through tonight. This system will NOT affect Florida directly, but the wind fields and dry-slots at various levels of the atmosphere (in different locations) will through today and tonight. 

In other words, the atmosphere over much of Florida is variegated. There is irrefragable proof as you will see in the images that follow.

 In NO LOCATION do values 'stack up' favoring rainfall...until possibly after or near dark tonight. Thus, the majority of the day will be spent readjusting, relaxing, waxing and waning...which leads to the first 3/4 of the day depending on Lake and Sea-breeze boundaries to interact to create thunder or showers.

It is easier to show the transformation and what is happening today via PICTURES...Please See captions:

Here shows the location of the low-level trough at 2000FT..the one at the surface is further west and very close to the East coast. It runs from the Upper Keys to Cape Canaveral. The dark green shows where the most low level moisture is located...SE Florida and North Florida. Enough for showers over SE Florida..BUT WHERE ARE THEY? All models show that by this time SE Florida should be covered in rain showers. Believe they will form over Interior Broward and Dade and Palm Beach Counties toward the Everglades shortly but high cirrus clouds might dampen their spirits to only showers..perhaps a thunderstorm where convergence is best. But high clouds are closing in...will they have an effect? To some degree I think they will.

Then we have the mid-levels of the atmosphere:
Moisture and wind at around 700mb (10,000ft) shows that South Florida is being dry slotted by the back side of the trough offshore, whereas the mid-level moisture is circled. This has changed almost zero since 7am...Overall, a part of North Florida has the best combination of moisture right now.  The greatest instability resides along  the mid-level moisture, mostly offshore. The area around the Cape and near Tampa has very high instability...perhaps to be tapped into with the sea breezes from early  afternoon through tonight.

FOR EARLIER TODAY: The Lake Breeze, Everglades "Affect" could generate some storms...but cirrus MIGHT put a damper on this activity. Hard to say for sure. The FURTHER the remnants of Emily move AWAY from Florida..the better the chances of rain and storms earlier... as time progresses, activity could get steered toward the SE coast, especially after 4pm. The dry air in the mid-levels over SE Florida seems to be preventing storms to form..but once they can...look out for lightning and wind gusts.  SEE CAPTIONS:

This is an example of where Earlier Afternoon activity COULD occur. Please read the captions. Note the affect of the Lake and Sea breezes could create some storms..but bear in mind, the mid-levels are pretty if one can get going..lightning FAR REMOVED from a storm is possible.!!  Same goes for North Florida. But do see those high clouds off the coast of SE Florida associated with storms over the Bahamas. Upper levels winds are projected to advect  (or carry/project) those clouds into South Florida heading into the afternoon...this might put the kabosh on the storms..but so far..the trough seems to be moving away...just enough to keep those cirrus clouds thin enough to allow development.

LATE AFTERNOON/MIDNIGHT: Believe the Trough (Sloth) of Emily's Memory (aka, Casper) will never develop into anything. However, as it pulls away, mid-level winds (as well as surface winds near dark)...will back toward  becoming from the NW-W rather than the NE as they are now, especially headed toward sunset and beyond. Activity from North Florida could send outflow boundaries East and South, whereas any activity over South and far South Central in Okeechobee and Martin Counties could send boundaries Northward.  Thus, those boundaries combined with increased low level moisture running from Osceola, Orange, Seminole, Western Volusia, Lake, Marion, and Flagler Counties could result in a 'string of pearls' along the St. Johns River Valley and into the Basin from JAX to near or East of Orlando. I'm also seeing a signal that with the high clouds having moved out (although after dark they have little impact)...A part of Palm Beach or Martin County could see some nocturnal activity.  If this activity can sustain itself in the middle of the COULD even reach the barrier islands or A1A corridor from Cape Canaveral to JAX between 10pm to 2am. 

Bear in mind, this is a big transition day. These days are very hard to predict in the summer, since there is no previous day to compare it to in regard to storm strength, motion, and how long they will last. However, last night's activity over the west side of the state lasted until perhaps we can take that as a sign.  FOR TONIGHT, below:
READ CAPTIONS. This is the current radar..note the lack of showers over SE Florida. This might have changed by the time I finished writing up this post, which takes about an hour.

SUNDAY/WEDNESDAY: Headlines should read: HOT along A1A from JAX to Miami. Some record highs possible. Humid, with threatening heat indices...esp. Monday and Tuesday along A1A. Some strong storms possible near the East Coast late day to early evening near SE Florida, Brevard, and North to JAX...mainly Sunday and Wednesday.  Monday and Tuesday might not see a sea breeze at chances of thunder might be limited. But, given the strong west to east steering aloft and moist air forecast, showers could evolve into storms from the west coast sea breeze as they progress toward A1A. Also note, there is a TUTT trough approaching the Florida Straits. It appears impacts from that will be limited to far South Florida and the Keys. If so, showers and storms might be limited to near zero on Monday or Tuesday...just have to see what happens with that entity in the next day or so.

THURSDAY/FRIDAY: Transition into more generic of days with the heat relaxing a small bit. By Friday...a tropical wave might be disrupting (or even Thursday) the cycle so fun -n-games forecasting will be in the cards....which leads to the TROPICS:

TROPICS: Many tropical waves are pooping far Pooping Up...popping up (typo)...over the Atlantic between Emily's Memory and Africa. It does appear that the period from August  12 through the 17th might be full of tropical discussions regarding this activity. Especially as we approach the 22nd. The one thing I want to point out is that all of these waves so far are projected to come off Africa at around 7-10 degrees north latitude. This is very far south..for an Atlantic entrance...and favors activity to threaten Puerto Rico time and time again...taking a track similar to Emily...Storms that can develop and pass north of Puerto Rico could threaten the U.S. East Coast from Florida to North Carolina...and those that pass south of Puerto Rico and the Dominican Republic could impact the Gulf side from Louisiana to NW Florida...and then there's those that go 'in between'. Just a heads up....NOW is the time to take casual preparations in one's spare time as the urge strikes...if in no other form than a mental or written checklist....

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