"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".

Saturday, November 5, 2011

Florida East Coast To Narrowly Miss a Major Gale Event Through Sunday

FORECAST PER the Rapid Update Cycle (RUC) Model for 2pm today. Shown is surface wind forecast to be 50kts (close to 55mph) offshore the Carolinas due to pressure gradient winds between High Pressure from the Mid-Atlantic to New England and a broad surface low east of South Carolina. 
EARLY SATURDAY MORNING: Strong winds are looming not too far away, but will never reach land to the magnitude at the coast of those offshore. Morning winds are NNW-NW and in the 5-12mph range to near calm. Latest radar shows very fast moving shower sprinkles not far offshore  awaiting for the surface low to move further to the ESE and the overnight inversion to break. Any clouds are limited to the immediate East Coast from Brevard and North and further inland toward NE Florida where the NE winds are starting to work in. These clouds will spread out with daytime heating after 11am or noon once the inversion starts to break.

7AM: Yellow shows morning cloud cover per infrared satellite image before the sun is fully risen. Current position of low and future first best guess track of this low through Wednesday afternoon. Rain chance impacts mostly from near DAB to Sebastian could spread South, especially on Wednesday with the only wind impacts (which will be minor) limited to north of Ft. pierce, and best chance/highest from Cape Canaveral to Playalinda Beach. (blue)

TODAY: The surface low will move ESE (East South East) through most of the day then begin to take a Southeast to South Curve tonight through Sunday. The morning inversion per forecast soundings will begin to break between 12pm -2pm andl lift from around 1200ft toward 7000 ft by 4pm. During this time, showers will work closer to shore and clouds will work SW into the interior as winds begin to pick up.

During this transition surface winds of 20-30kts per the RUC will swipe the east coast closet to Ormond Beach to Sebastian, with a big wind speed gradient between the A1A corridor and US1, sometime around 1-2pm. As of the latest RUC run of 6AM, winds of 30-34mph could impact the tip of the CAPE and very close to Port Canaveral from just east of due north. All models generally agree that rain showers will be possible after 2pm with a potential quick sprinkle before that time. The better overall chance of showers which could briefly make things 'wet' is  during a window between 3pm - 10pm, mainly along and east of I95 as far south as Ft. Pierce and north to St. August after which time the inversion lowers and the moisture depth becomes too shallow to support anything more than cloud cover.

Had things been set up with the low positioned another 200 miles further west this could have been a major east coast weather event. The other precluding factor reducing rainfall potential for this system is the cooling Atlantic Ocean waters since earlier in the month when the high rainfall totals occurred and waters were warmer and the fact that winds were unidirectional with height as opposed to veering

Overnight low at the Cape/PAFB was around 59-60F as anticipated but cooler all other locations. Today's high along the east coast will work through the lower toward mid 70Fs during the better cloud breaks prior to 2pm. Outside of the NE-and far Eastern South Central Portions other areas could get into the upper 70Fs toward lower 80Fs. More cloud cover could spread across a much larger portion of the state after 2pm until right around sunset.

TONIGHT: Winds decrease toward dark, especially inland as the inversion lowers and the stronger winds ride above the inversion. It still appears thus that winds at ground level will 'decouple' from the stronger winds at 2000 ft below the inversion,  and any sprinkles are restricted to just off the coast on the lee of the Gulf Stream after 10pm. By now, the air mass will have been modified due to flow off the ocean all day, with overnight lows near the coast in the upper 60Fs and cooler inland and west where winds will be more from the north under the decoupled atmosphere. Continued air mass modification through Wednesday with more onshore winds blowing across 70Fs ocean water temperatures each day from mid morning through sunset.

SUNDAY: So far, it looks like a replay with the inversion lowering at night and winds decoupling, then lifting toward 7500-8500ft feet from sunrise to noon allowing winds to work across the state. Winds on Sunday will not have the potential to be as strong as the low slowly tightens up a bit more, thus reducing the expanse of gradient winds. Low level flow becomes more diffluent as well, reducing rain chances. Coastal convergence with the land mass on the lee of the Gulf Stream as the low drops further south and opens up again toward afternoon should result in a more NE wind component up and down the east coast, with a chance of light fast moving sprinkles or showers and an expanding low level cloud deck across more of the state Sunday, and especially Monday as the low starts to retrograde more toward the W or WSW. At its furthest southern most latitude it should be offshore somewhere  east of Ft. Pierce to Sebastian inlet, but that position holds no bearing on sensible weather conditions (those that can be seen and experienced) for Floridians. Winds Sunday in the 15-22mph range, spreading inland during the day and lifting by late afternoon as the pressure gradient decreases.

MONDAY/TUESDAY: Low slowly fills and winds slowly lower to the 12-20mph range in the afternoon, spreading across the state during the day as the low drifts in a general west direction well offshore somewhere between Melbourne Beach to just north of West Palm Beach. By now, after 3-4 days of onshore flow the air mass will have been moistened and temperatures modified, with overnight lows inland in the 60Fs to upper 50Fs and lows at the coast in the upper 60Fs to lower 70Fs, cooler toward JAX/St. Augustine and perhaps by this time Ormond Beach as well due to  prolonged upwelling of deeper/cooler ocean waters from the offshore gale force winds.

WEDNESDAY: Frontal boundary will be on the approach while the surface and mid level low are at their closet position to Florida. The mid-upper level low will open into a trough and lift north as the approaching trough from the west is sensed and starst to become absorbed within the mean flow. Surface winds will back to the NNE-N or even NNW on Wednesday, by which time the fully modified air mass will warm into the upper 70Fs to lower 80Fs most anywhere. 

Wednesday has the potential (at this point) to be a very showery day across the entire East Half of the State from sunrise to just about sunset with NNW-N winds around 10-15mph during the afternoon with the closer proximity of the trough, but this will be watched in coming days to see if things can be a bit nicer in that regard.

THURSDAY: It is odd to have a N-NNW wind PRECEDING an approaching cold front, when normally they would be from the south. As the front approaches it encounters the narrowing wedge of high pressure between the' by now' filled low/trough which lifts north and regenerates toward the coast of the NE states. This wedge will likely squeeze out much of the rains and possible storms that could occur into the Panhandle region as winds back to westerly Thursday afternoon while the front approaches. 

West winds with a high in lower 80Fs depending on timing of the front. The front could go through nearly dry for most of the Peninsula, based on the evidence of the GFS with each consecutive model run going from wet, to less wet, to barely wet, and now dry. Northwest winds Thursday night with fropa and FALLING temperatures.

FRIDAY/SATURDAY: The GFS is taking back what it read yesterday, and is now calling for a "break out the parkas from storage" yuckcast, early winter like (by Central/South Florida standards) day with lows in the mid-upper 40Fs state wide. Highs on Friday might remain in the 50Fs. Another cold morning Saturday with highs in the mid 60Fs. But again, the GFS could be over playing the temperatures. Might not put that on the check list of 'honey dos' though, just in case.

The sun has now been up long enough, here is the VISIBLE satellite image of the SE states as seen from a camera from space:

BEYOND: Rejoice. Long range has been very consistent from run to model run with developing easterly winds becoming SE if not SOUTH for a good 5 days if not longer with highs in the lower 80Fs during peak heating and lows in the 70Fs (which looks a bit warm to me)..more than likely mid-upper 60Fs and highs lower to mid 80Fs (South Florida).

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