REPORT by Roger Williams, Bermuda Weather Service
Table of Contents
1 Introduction 1
2 Staffing & Operations 3
3 Storm Surge 5
4 Communications and EMO Considerations 7
4.1 E-mail communications 7
4.2 100.1 FM 7
4.3 Causeway 7
4.4 Prepositioning 7
4.5 Media 7
5 Data 9
Introduction
All aspects of the storm’s approach, progress and departure went very well from the perspective of BWS. The NHC track forecast was sufficiently accurate from an early stage that we had adequate lead-time to prepare staffing levels, and even work out roughly when we would be issuing watches and warnings. The intensity forecast was fortuitous, in that we were able to justify the level of communications with the EMO, DAO and the public regarding the extent of preparation, from an early stage. This in turn meant that most people took this storm seriously and made the appropriate preparations. Preparations made in anticipation of a hurricane which was a full two categories weaker than forecast when it actually hit us meant that Bermuda was in a much more ready stance that had the forecast been for a Category 1. If the forecast had been as accurate in terms of intensity, would people & agencies have made the appropriate preparations? This is difficult to ascertain until and unless we have a Cat 1 which is accurately forecast as such.
[pic]
Source nhc. - Infrared satellite image of Igor south of Bermuda on Friday, 17 September, 2010
Staffing & Operations
We had the ideal level of staffing to be able to run the operation – some staff lived in St David’s and were able to go home Sunday night, returning Monday morning via car. Others stayed the entire weekend. We would usually only have 2 people per 12-hour day and night shifts, but we actually had 4 forecasters and 3 observers on hand, along with the Director (myself). We intentionally planned to have staff (including management) prepositioned on the other side of the Causeway for continuity reasons, and to ensure there was a ‘fresh’ crew to come in and relieve us all once the Causeway re-opened. The staffing roster was adjusted to allow those who had been here all weekend to have a rest period of at least 36 hours prior to their next shift.
Food and water was purchased early on, in anticipation of supporting the crew through the weekend who might have had no scope to leave. Power, phones and internet never went down during the storm (we have a generator and backups but never needed them), allowing us to continue to do our jobs unfettered by technological limitations. Our trainign room was set up as a sleeping area for those who were off shift, with cots, air mattresses, and blocked out windows to the other lit areas of the office. The storm shutters were all down from an early stage also. Vehicles were secured in the lee of the ATC Tower and the alternate balloon launch/generator building early on. Bikes were secured indoors.
Power, phones, internet never went out, allowing us to continue to do our job unfettered by technological limitations. Instruments which had not been safeguarded against the effects of surge (most needed to stay in place for measurements e.g. windbirds, barometers) all functioned remarkably well, with the exception of the GOES Satellite dish, which (as expected) swung on its axis with the wind. Once the winds abated, GES put it back into alignment for us. GES a technician and the manager on hand 24/7 to safeguard critical airport equipment and bring it back up once the storm had passed.
We launched 3 balloons during the storm itself, and only one was successful. This was due primarily to the trees bordering the balloon launch deck at Met, which ate 1 balloon and 2 sondes. Only when the winds became a bit more southerly were we able to successfully launch.
Storm Surge
[pic]
Source:
This is a photograph from King’s Square in St. George’s, showing surge and wave action above ground level. We must discover a means by which we can make accurate storm surge predictions and observations. Currently there are no models on which to base accurate surge predictions on a case by case basis, and the one verifying point (Esso Pier) is in a location which is only helpful for the north side of St. George’s (where there are few properties near the water). We did get some help from the NHC Storm surge unit, but the estimates provided are vague and all-encompassing, instead of specific to each storm and location. This is not a criticism of them (in fact they provided some guidance, when none was available from elsewhere). However, we are not part of their modeling effort, as is outlined in this figure:
[pic]
(Source: )
Things that would need to happen in order to get to a better level of storm surge forecasting and observation:
1) Accurate and high resolution bathymetry and coastal mapping – this is vital to the effective modeling of surge. Without this, any accurate surge estimates that can be made will be so broad-brushed as to not be useful.
2) A real-time storm surge model which is configurable by storm, as opposed to a generalized model. All storms have their own characteristics, so comparing Igor to Emily or Florence would be inappropriate in term of surge, even though they all made direct impacts and were Category 1 storms.
3) Verification by way of measurement equipment – wave buoys and sea level gauges are necessary to give us some data on which to verify the output, allowing us to tweak the model appropriately.
Communications and EMO Considerations
1 E-mail communications
We’re not entirely confident in the Gov.bm e-mail system for communicating between government and ‘external’ partners (one of which BWS/BAS-Serco is, in terms of e-mail domains). That is why I set up an e-mail address on gmail, for the EMO, as a redundant backup. Not sure if it was used, or if it has been seriously considered. If gov.bm goes down, there are alternatives, and we should use them. Case in point – I received 50+ e-mails on the way back across the causeway, after the event was over. Had EMO/DCI used the backup e-mail that was set up, we would have received these e-mails when they were sent. Granted, it was unknown that the gov.bm domain was experiencing problems, but in the same way that the EMO website now stands separate from the gov.bm portal (), the email system redundancies need to be put in place in this fashion also.
2 100.1 FM
We at BWS need to work with DCI to feed them weather information on a regular basis. I think the public would appreciate at least regular weather updates in a standard format, with a prescribed (and publicized) programming schedule
3 Causeway
Had questions directly from agencies who were supposedly in the loop (COMOPS, Bda Regt, Fire Service personnel) about the status of the Causeway. I took great pains to advise them that no decision had been made by the Minister, however, I did explain that the wind conditions normally associated with closure were forecast for whatever time it was, and that they should plan accordingly. Communication prior to closing was better this time around, in that people had a heads-up about a) what wind conditions were associated with closure for this event, and b) a forecast of when those winds were likely; if members of the public continued to keep abreast of how the forecast was evolving, they had an informed set of information around which to base their preparation and actions.
4 Prepositioning
Going forward, and in light of unpredictability of the winds in these situations, I would advise that prepositioning of manpower assets not be cut so close. The Regiment was trying to get assets across the bridge before it closed – from what I hear it was very close, and if the winds had started up an hour earlier they might not have made it.
5 Media
Generally speaking the media reacted very well to this storm, treating with the highest priority, and accommodating our need to get the message of early preparation out there in the public eye.
However, there were some issues with overseas providers giving information which was at odds with what BWS and EMO were saying
– Accuweather (report from Gary) – one report talked about the potential for the lack of availability of refrigeration for drinking water for days after the storm passes.
– Tuesday morning after Igor had passed, Hott 107.5 had repeats of old broadcasts, including outdated weather soundbites from Johnny Storm, which referred to a ‘hurricane on the weekend’. This could have been avoided by the use of dates and valid times.
As a general rule, we cannot control what these overseas media outlets say about Bermuda, but the fact is that with so few providers here, and deviation from the main message can reach a large section of the public and cause confusion. I had one set of emails from someone in Texas suggesting that we should ‘evacuate the hospitals’. The scare-mongering on the part of the international media is something we should be aware of and take into consideration.
Data
Post Storm Country Report
Country: Bermuda
Tropical Cyclone: Hurricane Igor
Dates of data: 19-20 September 2010 Date of issue:
| |Maximum Sustained Wind |Maximum Wind Gust |Calm |Total |Minimum Sea |
|Station | | | |Rainfall |Level Pressure|
|Direction ° True |Velocity
Knots |UTC Date/Time |Direction
° True |Velocity
Knots |UTC Date/Time | |mm |hPa | |Bermuda Airport TXKF (10 min avg) |150 |59 |20/0223 | |81 |20/0218 | |81 |964 | |Bermuda Maritime Operations Centre[1] (formerly Harbour Radio) | | | | | | | | | | |Fort Prospect[2] |127 |51.5 |20/0350 |166 |90 |20/0530 | | | | |St. David’s[3] |166 |79 |20/0550 |166 |102 |20/0550 | | | | |Commisioner’s Point[4] |133 |70 |20/0340 |133 |101 |20/0340 | | | | |
[pic][pic]
Source: Hinson’s Island automated weather station (privately owned)
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[1] 32° 22' 49.5582"N, 64° 40' 56.769"W Elevation 255ft AMSL – 1- minute average
[2] 32° 17' 57.6882"N, 64° 45' 53.4774"W Elevation 230ft AMSL - 10-minute average
[3] 32°21.825’ N 64°39.368’W, Elevation 159ft AMSL - 10-minute average
[4] 32° 19' 44.5584"N, 64° 49' 55.9596"W Elevation 262ft AMSL - 10-minute average
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