In the storm, we can't remember the name, but the pressure dropped down and the wind blew insane"
Events over Florida of October 7-9, 2011, leading up to....
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| Storm 10-911 (10-9-11) ! |
Some of the events that led up to the final escapade that prompts the question, "Should this storm have been named?" when all was said and done.
The initial weather pattern leading up to the time in question was expected to be a wind/rain event as first noted by the Melbourne, Florida National Weather Service extended forecaster on Duty, Mr. T. Cristaldi (and followed up later the same morning here) was not a tropical or even sub-tropical one.
As noted, a blocking pattern was to set up with high pressure over the Mid-Atlantic that was to be reinforced from a secondary high pressure area from Canada. Meanwhile, low pressure was mounting in areal coverage from the Florida Straits and into the Caribbean along and south of the old cold front that brought the state the first hint of fall on October 1st.
It was posted here originally that I thought it looked like an OMEGA BLOCK was going to set up, but that quickly changed to resemble a REX BLOCK as noted by the NWS office. Technically,I'm not sure either case was absolutely true because for these blocks to form in 'text book fashion' both areas would be cut off from the main Northern Hemispheric circulation. It was quite close though, and even that could be up for debate.
In this case, the low pressure area was far enough south to not be part of the circulation, whereas the high pressure had nearly cut off with a large trough well to the east . Recall there was also a trough approaching from the west that nearly cut off in the upper levels toward the SW U.S. That would have made for an Omega Block. So, and only from the perspective of this writing for entertainment purposes, I'm thinking of it as a "Modified OMEGA/REX Block". This term does not exist to my knowledge technically ..but it harbored both aspects of an Omega and a REX Block, but not completely.
It was within this block that Florida found itself within a tightening pressure gradient portion of it that brought the high winds. On the other-hand, the weather over the Great Lakes and most of the NE states was gorgeous where it had been previously wet and cool for a long duration when a cut off Low had established in this area just 10 days earlier. In fact, it was not until that cut off low (a blocking pattern as well), moved well off the U.S. NE Coast that the newer pattern could establish over the SE States.
The deepening easterly flow from the surface to 700mb was discussed in depth early on, and was described in posts as "Phases I, II, and III) early in the week to midweek as they unfolded ..it was when the flow became deep enough (or higher up in the atmosphere) that heavier rains and squalls began in full, Phase III.
Despite all this wind and rain, it was not a case for 'naming' the events that were on going. Not until there is a closed low pressure area at the surface does the 'naming' come into consideration.
Such a low appeared to take shape toward the NW Bahamas on the evening of the 8th. The old frontal boundary (cold front of one week earlier) lifted north, pivoting from the west side and lifting north on the east side. As the boundary lifted north the pressure gradient (between high and low pressure) increased across Central Florida leading to the events of Sunday, as anyone who was in Florida can relate too. Unusually high tides, minor beach erosion, rising waters and waves on the intracoastal waterways, and squally weather continued. Along 528 between Cocoa Beach and Merritt Island it can still be seen where the river breached the banks and flooded over where no barricades had been previously put in place. Water is still over the banks in a few spots where the shore was eroded on this Wednesday, October 12, 2011.
OCTOBER 9 - The Day in Question: It was on this day toward early afternoon that a tightly confined and consistent cluster of strong thunderstorms moved north to NW off the Florida East Coast which developed offshore Vero Beach. Winds in this location increased in that area, and power outages began to filter in. It lofted NW- WNW to almost West toward Brevard County. The NWS in Melbourne issued high wind and Flood warnings especially for that point in time, and had been issuing lower key statements prior to the warnings in their Blog updates. TV news stations were put on alert and the NOAA Weather Radio was emitting the warnings as well.
It first appeared it would impact areas as far south as almost Ft. Pierce to north of Brevard, but as time went on the area of interest shown above lifted further north and parallel to the coast inching only closer westward with time as it reduced in size. The blue lines were drawn in at the time in order to point out that it was a coastal event, per the rain at the coast that was creeping west with time.
However , the area offshore lifted north more and more, then started to take a hard left (toward the west)
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| At this point, I was listening to Led Zeppelin's Song, "When The Levee Breaks" |
It started taking on more striking features on radar during this time, almost like banding around a tropical storm, but there was no center of circulation visible on radar or satellite imagery. It also increased in strength for a 'blob' with almost no lightning to abudant lightning after 4pm -9pm. The HRRR model was showing what looked like a "SuperCell Thunderstorm" at one point to cross exactly where the 'center of circulation' eventually crossed many hours later. That was about the 15Z run of that model, but cannot say for certain. It becomes available on line several hours after the fact. At this point, the system was being more regarded as a potential low end tornado threat rather than a tropical one, as SPC also had this area under a "See Text" for a 2% Tornado Risk and strong wind risk . A second blog post was issued on this day as the new and evolving events began to unfold. Both the early and mid-afternoon posts are available (the image (below) included in the later post):
http://highspeeddirt-steve.blogspot.com/2011_10_09_archive.html
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| The Green Area Shows Where the Storm Prediction Center (SPC) based in Norman, Oklahoma had issued the small tornado and wind threat. In blue was the modified version, unofficial for purposes of the blog posts, posted in the morning of the 9th. The SPC version was published earlier in the day, whereas the blog post was not issued until several hours later when the sun had been up a while and conditions to the south were improving conditions |
It was near 11pm the lightning activity began to cease..as the remaining convection moved ashore on the north end of Port Canaveral, toward the Kennedy Space Center, to along SR 3 in North Brevard near the Haulover Canal. At this point the boundary I've referred to as a warm front (not completely technically correct) was near or just south of Melbourne , Florida...and the pressure gradient was very tight along a narrow passage just north of that boundary where it met the strong high pressure to the north. But.....
The lightning ceased, and surface air temperature around Cape Canaveral at my place fell to nearly 68F degrees, almost the coolest it had been since early spring and one degree shy of the coolest morning yet this fall season. Then after approximately 10 minutes of uneventful weather, an interesting thing occurred in Cape Canaveral as I observed. The wind began to pick up again, from almost due north this time. I big change from the ENE-NE wind of the past two days. It seemed like more a fluke, perhaps outflow from the remaining storms to the north (?), but it increased steadily. A closer look at radar, and an interesting feature became visible within radar range of MLB's WSR-88D Doppler Radar.
An "eye like feature" to the ENE of Melbourne clearly was showing what looked like counterclockwise circulation as if around a central core of low pressure when viewed in animation mode (using weathertap.com) similar to that of a tropical cyclone's eye. If there was a circulation , just like the HRRR model implied for a supercell (a rotating thunderstorm,) it was now just offshore but not as a rotating thunderstorm. Realize the supercell thunderstorms do not have an 'eye', the entire storm rotates.
Something else was apparently rotating as it lifted NW then turned WNW and into North Cocoa Beach toward Cape Canaveral. A look at the Radial Velocity revealed:
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| The strongest inbound winds are shown in the darkest blue just off the tip of the Cape and heading toward the north end of Port Canaveral. The red is outbound winds relative to the radar's location. |
Rhe air pressure on my home weather station (but who knows how well it can be trusted) indicating a RAPID fall in pressure from 29.82" to 29.70" in less than an hour.
Also note the 00Z Forecast from the North American Model (NAM) for this time frame for 2AM. It is 'slow', but does show the closed low roughly east of Sebastian Inlet:
Actual data that appeared from the Local Data Integration System (LDIS), a conglomerate Space Flight Group/NWS effort. Compare the image above and below, and note they both picked up a 'low', but it does not look like a Tropical Storm at all. But, it is a low, with tropical storm force winds on the north side.
As this apparent circulation approached the temperature rose from 68-69F to 74-75F degrees on my porch , even while it was raining. This should have been a cold, outflow like wind from storms to the north, but it was not. It was warm wind.
Wind shifted in MLB to westerly while my location in Cape Canaveral just south of the Port had due North Winds estimated at 35G67mph (tops) in one quick squall. The prevailing mode was more closer to an estimated 30G48mph at my location...which lasted 50 minutes. Rainfall of 2.67" was received in only 50 minutes and the storm total was 2.75" for the 90 minute period, although with how strong the wind was at this time I can't be certain that total rainfall was not even more. Rain was over-flowing the rain eaves above, which I've only witnessed on 3 previous events in 5 years. Radar estimated rainfall did not catch the high rainfall in Canaveral from what I could see on Weathertap at all, and I'm not sure if Melbourne's radar picked it up either. It is possible it was below the radar beam, since it all appeared to be very low level activity for the majority of the time. In fact, at times we could see the Full Harvest Moon in brief cloud breaks.
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| On Shore Centered Close to Port Canaveral shortly after midnight |
And the latest LDIS Plot at the same time as this radar image above is below. Note how tight the isobars are shown here AROUND THE CENTER, and not depicted as a tight pressure gradient between two opposing much larger non-tropical systems. It was during this time the weather station outside registered a barometric pressure of 29.47".
It is only for this odd mesoscale feature that I'd think the system would have a potential to be named.54ft towers near the north end of the Cape measured a few gusts from 75-81mph as well.
It is important to note that most of the strongest winds worthy of rating this as a named storm occurred only in gusts, but might have been sustained toward the Port and further north toward the Haulover Canal or off the east coast. A cruise ship leaving harbor (I saw it going out to sea later in the afternoon as the system was approaching) relayed they encountered 'great difficulty', more so than expected.
Despite these winds measured on land, we'll never know how strong the winds were offshore as well due to lack of denser buoy data. The items of interest in my mind that would give this final 'obscurity of meteorology' the potential to be name worthy are:
1) The rapid drop in surface pressure (not related to pressure gradient winds)
2) The abatement of lightning as the system could have become warm core to higher altitudes which is not favorable for lightning activity, but denotes a tropical system;
3) The rise in temperature at ground level despite the fact the wind was coming from the north in my location, and from the direction that cooling outflow from earlier thunderstorms would have come from ;
4) Even as the moon appeared in full, the wind continued sustained est'd around 30mph with gusts to 45mph with horizontal rain.
5) It might be that the strongest measured winds at 54 ft were a result of both a tight, low level circulation and pressure gradient winds combined.
If this were to be named, perhaps it would be the first "hybrid sub-tropical storm gone near extra-tropical" all within the course of 4-6 hours.
From the perspective of a Storm not to be forgotten in the annuls of meteorological research and history, perhaps it should be named for historical purposes. Would naming the storm affect those looking for recovery from insurance companies (for better or worse)?
Names are not dealt out solely for the purpose but other factors both pro and con abound for why or why not it could be named. Post-event naming has occurred in the past.
The series of bizarre events leading up to the night of '10-911!' are not truly defined well enough to argue either way, nor is the availability of data surrounding the system during this time in-depth enough. It is within the hands of our scientists at the National Hurricane Center in collaboration with NWS Employees to decide (if they are even giving this storm event a second look).
Will we, the witnesses, be forgotten like salt spray in the wind once the storm's flood waters absorb back into the ground and vaporize into the air as the beaches recover?
For a personal video now posted on YouTube, See:
http://www.youtube.com/watch?v=uZX74NxHBZw
Meteorologist, Stu Ostro, from The Weather Channel, has posted a discussion regarding this event (link below):
http://www.weather.com/blog/weather/8_25746.html
Crown Weather Services, Rob Lightbown, was also concerned about the potential for an event to unfold, and his daily weather update for this day reflected that fact early in the morning. His feature/main page is located below, and is updated most every morning as tropical weather season is in progress, as need be:
http://www.crownweather.com/
The National Weather Service out of Melbourne issued prompt and due warnings, in any event. So there is no argument either way that people were not warned for tropical storm like conditions in the areas that were impacted on this day.
And Thanks to Weathertap.com, whose services have been always necessary and reliable
and to Twisterdata.com, where the weather model data provided at this site proves beneficial innumerable times .
STORM: 10-911
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