"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".

Sunday, July 31, 2011

Isolated, Becoming Scattered Lightning Storms Possible Today

A very, very large sea gull flies over the Atlantic Ocean Saturday Morning, July 30th. Can you see it? I'm standing barefoot in the warm Atlantic Ocean water. These warm waters are creating high dew point temperatures along the A1A corridor of North Brevard, with high heat indices as well, even though the temperature is only at or just below 90F in those areas (Such as Satellite Beach toward Canaveral)

TODAY: The suppressing affect of the mid-high level pressures that were over the Western Panhandle of Florida yesterday is relaxing. Florida was on the descending (sinking air) side of those highs, and thus as expected, rain fall was very very sparse. Since yesterday, the high pressure has retreated far to the west toward Eastern Texas and Mississippi, and is expected to retreat even more so during the day. With that in mind, although the wind aloft has not changed in direction all that much, it is much weaker, and air pressure aloft is lower. This allows for better mixing of the low level moisture with the mid-levels.  There is already much more moisture as evidenced by the increased PWAT as much as 1/2" over yesterday, ranging from 1.9 -2.1"..focused more toward the North Half of the state. I expect these values might get higher by late afternoon as moisture convergence at the low levels due to Lake/Sea breeze boundary interactions occurs and lifts low level moisture into the mid-levels.

Otherwise #1. Temperatures aloft are really not much different than yesterday, maybe one or two degrees cooler over the SOUTH HALF of the state in the mid-levels. Makes sense right? That area is further from the retreating mid-level high pressure region now located as shown in the image below well to the WNW of the state.  Latest SPC mesoscale analysis shows some pretty steep mid-level lapse rates lurking just off shore the Central and South Florida east coast, but whether those values will translate over the land mass cannot be determined., since when running a loop they simply seem to shift around in location, but remain off shore. Steeper lapse rates implies better lift due the thermal mechanisms, rather than 'forced' lift, such as created by wind boundary collisions.

Otherwise #2. Winds at 2000 ft this morning are from the W-WSW along the coast of Central and North Florida. This will delay the east coast sea breeze, which will remain light until around noon time, and not really let its presence by known until about 2-3pm north of Vero Beach. It will begin sooner over South Florida and interact with the Lake O breeze.

THUS: Expect we could see much greater coverage of showers and thunderstorms today. Cooler temperatures aloft (barely) over South Florida and sea/lake breeze boundary interactions could generate some very lightning prolific storms over Western Palm Beach, Broward, and Martin well as toward Collier County and over the Everglades.  Boundaries could force storms into Western Indian River County, maybe Extreme SW Brevard. Other storms very close to the coast will occur (more isolated) in Volusia.  

In general, most activity will be restricted to 3-5 miles away from any coast today..with the best chances of shoreline activity over SW to West Central Florida and perhaps in Volusia County.  The greatest concentration should be over the South 1/3 of the state. Outflows could generate further activity back toward the east in Central and South Florida in the interior...and perhaps even send an inactive boundary back to A1A after 9-10pm tonight anywhere along the East Central to South Florida Coast. There could be some lingering storms over the interior until 11pm - midnight.

MONDAY: Much the same as today. Increased activity Tuesday/Wednesday.
Zig Zag lines are Ridge (high pressure) Axis'. The low level one is over East Central Florida, while the others are for the mid-levels. The legend speaks for itself in what the color code is for. In short, best concentration of storms with frequent lightning near Lake Okeechobee, SW Florida, and West Central Florida just west of Orlando Metro into West Osceola Counties, Polk, and Lake Counties. Other more isolated storms elsewhere, with probably less lightning due to less Low Level Forcing. Although, Lake Harney, Kissimmee, and those in Lake County could play in late today.

TROPICS: Sticking with the GFS for now, since there is little else to go by other than the Tropical Forecast Track Plots from guidance such as the LBAR (and 20 others). Still, these tracks for the most part are taking a developing tropical system which will likely become a depression to tropical Storm Emily in the next 24-48 hours roughly toward Puerto Rico. When push comes to shove, the system is forecast to curve just east of the Bahamas or along its eastern most islands and head toward Bermuda.  The GFS has been very consistent with this scenario, so holding on to its depiction for that reason....consistency. So far, this has been the Worst Case Scenario (to bear in mind) as far as a significant tropically developed system is concerned.  As should be expected, if the storm takes that track, it will be at its strongest right before it makes its most due north curve in the track..which would be about 225 miles east of West Palm Beach to that far east of Melbourne. This should be occurring around Friday night through Saturday, and is a representation of the Coriollis Effect which accounts for the earth's rotation and that parameter coupled with latitude/directional storm motion. Kind of complex, but point is, there is a reason for that notwithstanding other parameters that could negate this.

However! At this point, this is all speculation...could call it pure speculation now hedging on what seems to be a  'possibly , maybe good guess'. Either way, we are going to be hearing about this storm A LOT(!) in the weather arena for the next 8 days...get used to it. It should look very impressive on satellite presentations if nothing else, again, under the preconceived .."better than 1/2 baked extrapolations" at this point.

BEYOND: Under the assumption the Hurricane Emily takes this track (at time, expect it to peak as a strong Catergory 2 , minimal Cat 3 so far)...rain chances will go down for 48 hours during its closest pass and just prior to that, of Florida. This would be Thursday night through Sunday. After that point, the GFS still insists on a long term trough in the mid levels down the U.S. East Coast placing the state in moist, W-SW Flow aloft. Some days could be quite warm along the east coast if this will be the case, maybe even absent of a sea breeze on a day or two. Mid-level temperatures should be cooler once the Storm is far removed for the region. There are no other tropical concerns beyond "Emily", but the troughiness near Florida will need to be monitored for any unforeseen developments heading toward August 10-13 time frame.

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