"But seeing they could not See; hearing they could not Hear"
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"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".

Thursday, July 15, 2010

"Back in the Saddle-Point" Today

(Image: Latest image courtesy of the NWS and LDIS shows a pond of low lapse rates / Theta-E in the mid levels over Brevard)
RECAP: Rain activity materialized yesterday as forecast both in timing and locations was later in the day that the coverage of shower/storm activity was a total "fail". There was a strong storm or two far away...but they were very few and far between. The only cause I could come up with as to why this occurred was the warm mid-level temperature of 10C at 700mb.

SYNOPSIS: As was the case yesterday, this morning most of East Central Florida remains between high pressure to the east and high pressure to the west. Additionally, we have a tropical inverted low pressure trough passing to the south with another trough digging down the U.S. east coast which ends to the north. In other words, we are positioned in East Central Florida in what is known in meteorology as a col, or neutral position (the saddle point)... we're neither here nor there.

LOCAL ANALYSIS: The included image shows an area of very low 950-700mb Theta-E over Brevard County. Such an area was over North Central Florida yesterday which I believed would greatly inhibit rainfall chances for at least the first half of the day for that area (which indeed was the case). The area isn't quite as strong though today, but it is over this area now. Otherwise, morning rawinsonde data shows a continued moist air mass with a PWAT at 1.97 inches -- just a neglible tick lower than yesterday. This is definitely ample moisture for shower/storm generation. 700mb temperatures remain nearly constant from yesterday at +10C though, but 500mb temperatures have dropped about 2-3 degrees. A light easterly wind component is becoming apparent just above the surface all the way up.

TODAY: Partly cloudy to occasionally cloudy to start the day. Early sea breeze and no rain along the immediate coast, but some widely scattered showers are possible between the US-1 to I-95 corridor between 11am - 1pm anywhere from Vero-Daytona. High pressure from the east will eventually build in during the course of the day exerting a SSE toward the NNW push of any activity that does happen to form to the inland counties west of Brevard and Indian River County. Further south little if any activity is expected. The most sincere efforts will be made for storm generation inland where Lake Breezes meet the East Coast sea breeze. Activity could be more widespread and stronger today due to the cooler than yesterday temperatures cited at 500mb. Do not believe the west coast sea breeze will have much of an influence except well west and north of Orlando
TOMORROW THRU MONDAY: Timing of rainfall nearly impossible to predict with a reasonable amount of accuracy. Suffice it say that we will be placed right along the western periphery of the Atlantic high pressure system for quite some time (well into next week). This will make the East Central peninsula open to both totally dry lapses as well as potentially wet periods lasting anywhere from 6 hours to 2 days contingent upon what comes out of the the tropical Atlantic.

For instance...currently, a TUTT low is approaching the eastern Bahamas with a tremendous amount of mid-upper level atmospheric subsidence and a dry Saharan Air Layer (SAL) air slot wrapping around its west side. The dry, dusty air already impinging on the Bahamian Chain is clearly evident on satellite imagery time lapse, so it's not that far away. The jury is out as to whether this area will actually reach our coast during the next 24 hours. If it does that would mean no rain for that time frame until the TUTT passes on...which would take about 18 hours. Latest animation suggests that the 'severely' dry area is thinning though and slowing in forward progression as the TUTT heads this way. Beyond this feature, there are no other immediate items of note looming on the horizon, and I don't anticipate there will be any for a few days.

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