"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".

Tuesday, August 23, 2011

Unique Day For Florida Weather - Pristine Irene Not So Serene

BLUE LINES: Weak Sea Breezes (and none) at 11AM and an Outflow Boundary From Large Thunderstorms off the NE Florida Coast (also in blue) is progressing toward the State

TODAY: A tough forecast today for the region North of Ft. Pierce to Sarasota mainly. Moisture is ample at all levels for the most part, but what is currently shown could change. The biggest "?" in this area is along the east coast east of I95 as well as how the moisture levels at various components of the atmosphere (levels) will change during the late morning through mid-afternoon in what appears to be a mostly unchanging atmosphere other than normal sea breeze development. It is possible the east coast sea breeze will move little from the coast until the outflow boundary gets into closer proximity of the coast north of Vero Beach.

SOUTH FLORIDA: Most diurnal type mechanisms seem to be in place in South Florida today with ample moisture, only very light sea breezes, and no prohibitive factors for rain and thunderstorm development at play. Once initial activity sets outflow boundaries into the area, those combined with the lake breezes and subsequent additional outflows could fill this area in with precipitation fairly well. It is after 3pm that the most lightning type activity should develop as boundaries meet just away from the coast and/or along the depth of the inland penetration of either coasts/s sea-breeze. There could be some odd ball strong storms created by the washing-machine circulation created over the Everglades that might produce a 'surprise event' along the South East of Southwest coast. 

TOWARD CENTRAL/NORTH CENTRAL: Having a hard time envisioning the sea breezes actually meeting today, unless until very late. Winds aloft are quite light,, and just at or near the top of what might be the normal vertical depth of the sea breeze winds are light from the WSW. This could greatly delay the east coast sea breeze from Brevard and north..or at least make for little inland penetration beyond I95..OR..leave the sea breeze to develop but leave it quite which case. storms might not be able to form along it...but if the can..could be quite lightning filled. 

The other perplexing factor today involves the outflow boundary visible on satellite imagery late this morning. It appears to be approaching the state with arrival around 3pm or during peak heating hours. It might even be sensed by the atmosphere PRIOR to its arrival due to mass convergence ahead of its push.

Should this boundary arrive either before or shortly after the east coast sea breeze develops, some stronger thunderstorms could occur both along, behind, and just ahead of where ever the sea breeze is located at that particular time. Thus, the Big "Huh"?  

Two Scenarios: The front never makes it to the coast, at which point more sparsely dispersed shower/storm coverage would follow with generally cloudiness in other locations...with better chances late today away from either coast as outflows from the activity over South Florida propogate.s northward along the leading edge of outflows from along and north of Lake Okeechobee.

The other scenario is that this large frontal outflow drawn above does make it to the coast. If that is to occur, storms could be much stronger along the sea breezes where it has developed, or perhaps, the sea breeze will not even be required.  Likewise, the outflow with the cool air behind it might only create general cloudiness and less coverage. I'm not weighing or depending on that side of the coin today. Thus, storms developing along, near, or just west of the immediate sea shore with those resulting in propogating outflows WSW-SW ward. Coverage in this case would be quite generous. Some of the early activity (which would be in the early to mid afternoon could contain quite a bit of lightning...) and some stronger wind gusts over South Central Florida (South of the BeachLine).

More activity could be ongoing over South Florida and further inland and toward the west coast until nearly midnight...per Scenario number two.

WEDNESDAY: Another tough call. The latest NAM run indicates plentiful moisture but no rain as winds at most all levels become more umiformly ENE with time ahead of Hurricane Irene while it is on more of a NW course.  Perhaps this will equate to more of a showery regime, but if much? There are no definities tomorrow in the morning we will have to see just exactly how much moisture we have to work with, where in the atmosphere it is located, and how strong (not strong mind you)..the wind will be. Normally, I'd think near uniform flow from the ENE would equate to wide spread small rain showers and maybe some thunder as storms progress toward the west coast (at this time of year). But given we also have a hurricane in our midst and its surrounding envelope (macro climate within)...the exact impact..if a bit hard to determine. With those winds, the temperatures especially near the coast should not be quite as warm tomorrow..but far from 'cool'.

THURSDAY: The forecast for Thursday and Friday is solely dependant/contingent upon what influences Irene (if any) will have.  Surely there will be marine impacts of high seas and rough surf..with rain offshore in squalls. Model guidance is coming into alignment so closely in regard to the cyclones track that it is almost scary.  There is only one 'fly'.

Per the official discussion and as I'm observing, the storm was expected to become a MAJOR hurricane...however, despite the fact that it will be entering very warm will also be entering a shearing deformation zone produced by the decaying presence of a 700mb trough (the one responsible for the storms off NE Florida at this time). With that, no intensification beyond what it has at the time it gets east of Cape Canaveral is expected.  Pristine Irene , of so serene, could have only minor impacts to those locations mostly east of I-95. 

And, if the official forecast holds true, we will hardly know it is out there.  However, any further west ward track closer to the coast will make the difference between night and day in regard to wind and rain. Therefore, consult local forecasts issued by the NWS in MIA, MLB, JAX, and TPA for the official outlook...after the morning post is made these  days .  Chances are, we will already know the scoop at 'blog post time' because by then we will know where the storm is and which way it is least with respect to Florida.

PRISTINE IRENE (The Younger Sister of Serene Irene by 5 Years): As stated above, other than marine concerns, impacts are not looking bad at all for Florida. Even as late as yesterday afternoon one model had it headed toward Vero Beach. Therefore, it is advised to closely monitor the storm until it gets north of Cape Canaveral. It is at about that point it should be its strongest .

If any changes occur other than 'the expected' before that time, we will surely know about it through a variety of outlets. The NAM has even come into agreement with all other models as of 8AM..which previously was an outlier along with the GFDL. I will say though that if the storm takes the present forecast track, impacts for Florida will be minimal to zero other than the rough seas...seas near shore are not expected to be substantially large enough to create beach erosion.

In lieu of posting my ideas or thoughts of what I think might happen, I leave that to the NHC (The Hurricane Center) and the Weather Service to release only official information. Otherwise, one man's word becomes another man's gospel. ..which is passed on to another person (and altered a bit)..and before you know it ..the rumor mill as mulled up a witches brew of down right lies by those so inclined to generate fear and apprehension amongst the meek and mild mannered.

BEYOND: Showers and thunderstorms will be once again  be possible later in the weekend as Irene is well away..with very warm to hot coastal afternoons due to the lack of a sea breeze until Irene is 2 days out of the picture, at least.  The storm could end up not striking land at all..but if it does..the saving grace is that since it might even weaken from the already now forecast reasons stated above...where it does strike will not be nearly as great of an impact as previously envisioned (But, it would still have a major impact to coastal communities if it does meet or get very close to any coastal area).  

Keep attuned at times during the next 48 hours regarding Irene though. If it does gain more momentum as was thought up until just a few hours ago..a very strong storm would or could change the forecast track as much as in a drastic fashion...and we don't want to be caught off guard by some sudden NW motion as what has happened in other locations in past when Major Hurricanes are in the midst of near approach..additionally, if its forward motion for some reason slows down for any length of time..that could also change the expected storm track down the line.

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