Giving Sandy A Little KC Perspective
Once again the focus for the blog will be on this potentially historic storm affecting the eastern part of the country. Since yesterday there have been many developments, some of which I’ll write about this afternoon. As I do so however; I thought I’d put a little bit of a different perspective onto the storms size and some of it’s effects so far.
It’s believed that in terms of SIZE…not strength…that this may be the 2nd largest tropical system to have developed in terms of wind generation. It’s more than 850 miles across, from side to side as far as it’s ability to generate winds of tropical storm force or greater (39 MPH+). To put that into perspective, if you got in a car and drove from Kansas City to Pittsburgh, PA(!) that’s the size of the wind field of 39+ MPH winds. In the weather world that’s incredible. Those are steady winds, obviously the closer you get to the heart of Sandy the stronger the wind fields become and if anything the core of the stronger winds may get a bit stronger over the next 24 hours as the storm starts ingesting the dynamics of the cold air lurking to the west of the storm.
Take a look at the immensity of the storm from NASA’s point of view.
This morning the mayor of NYC (who should’ve done this yesterday in my opinion) ordered an evacuation of almost 375K people from some of the low lying areas around the city that are prone to flooding or what they refer to as zone A. They break the region down into 3 zones for flooding purposes from tropical systems/Nor’easters. Zone A as shown blow in the darkest of REDS are the people who are being told to evacuate NOW. Click on the following image to make it larger. (Courtesy of http://project.wnyc.org)
Now if you’re wondering HOW MANY people that covers…it’s close to about 375K. So let’s put a little local perspective on that. That would be roughly the populations of Olathe, KS (128K)…Overland Park, KS (176K)…Spring Hill, KS (5K)…Blue Springs, MO (53K)…and Pleasant Hill, MO (8K) and then some. Now imagine telling all these people that you need to get out in the next 12-18 hours. Pretty impressive numbers!
There really has been no change in the data today. The storm is holding it’s own and may be trying to tighten up a little this afternoon. The eye of the storm looks a little more impressive this afternoon as you can see by looking at the satellite pictures.
As mentioned the modelling data continues to point to a landfall close to central NJ. Here is the latest NAM model.
While the persistent wind will be an huge issue for power outages, one of the bigger issues may be flooding. From rain coming from the sky south of the NYC area towards Washington DC for example…and from the sea itself. Here is a look at the latest rainfall estimates…showing a large area of 5-10″ rains possible south of where the center comes ashore.
The other, perhaps bigger issue is the potential for the coastal flooding. That’s why all these people are being evacuated. The storm surge for this is going to be much bigger than what a “typical” category 1 hurricane will generate, in terms of the amount of surge and the expanse of the surge because the system is so large and taking an optimal track for the biggest surge to be generated.
Remember that the sea-wall in the NYC area is only some 5 feet above mean sea level. Tomorrow night is a full moon so typically you’ll have tides that are running high. Add in the fact that you have this massive storm (already producing water levels 2+ feet above normal in the NYC area). When Irene came ashore last year it came to within 1 foot of topping the sea wall. Here is a look at how things are going in Battery Park, NY.
Notice the green line in the 7 foot territory per the modelling data. That’s trouble with a capital T. IF water gets into the subway system there then there are tremendous issues since some 8 million people ride the subway each day. As a result of the storm, it’s being closed down at 5PM this evening. The schools are closed for tomorrow but yet the financial district is supposed to be open for business. According to the website Climate Central, a 5 foot rise in the water levels would impact over 230K people and put almost 101K homes/residences in jeopardy. Should the water levels reach 7 feet, some 750K people are threatened along with some 200K homes/residences. There may be some overstatement of the numbers I think, but you can see this would clearly affect tens of thousands of people. As a matter of fact the NWS in NYC just sent out this tweet. “Predicted water level of 11.7 ft at Battery, NYC at 8:13PM MON would break record of 10.5 ft on 9/15/60 w/ Hurr. Donna.”
There are some important differences between barely Hurricane Irene and Hurricane Sandy, even though technically there winds will be similar in strength the most important I think is the size of the storm and the angle it’s taking to maximize the storm surge into the NYC area.
As far as flying goes according to Flight aware, some 1700 flights have been cancelled already today with more that 3700 already cancelled tomorrow.
Finally a few words from the NWS offices themselves…note the language being used to describe what may be coming so there is NO mistaking the severity of the situation. This from the NWS in NYC.
“IN TERMS OF WINDS…WINDS GRADUALLY INCREASING TO TROPICAL STORM STRENGTH SUNDAY NIGHT INTO MONDAY MORNING. THE STRONGEST WINDS WILL BE COINCIDENT WITH THE CLOSEST APPROACH AND LANDFALL OF SANDY…MONDAY AFTERNOON INTO MONDAY NIGHT…WITH POTENTIAL FOR SPEEDS OF 40-55 MPH AND GUSTS 70-80 MPH. THESE WINDS COULD BE 10 TO 15 MPH HIGHER IN ELEVATED LOCATIONS. IF THESE WINDS ARE REALIZED…THE COMBINATION OF EVENT DURATION…SATURATED GROUNDS…AND PARTIAL TO FULL FOLIAGE TREES…WOULD CAUSE WIDESPREAD DOWNING OF TREES AND POWER LINES…CAUSING DISRUPTION TO POWER AND POSSIBLY TRANSIT FOR SEVERAL DAYS. THESE WINDS WILL ALSO RESULT IN SIGNIFICANT COASTAL IMPACTS…DETAILED IN THE TIDES AND COASTAL FLOODING SECTIONS.”
Now from the NWS in Philadelphia (Mt Holly, NJ)…
“VERY LONG DURATION AND LIFE THREATENING FLOOD EVENT IN NNJ. FCST BASED ON COMBO OF ETSS… ESTOFS AND NHC PSURGE. FLOOD OF RECORD LOOKS LIKELY AT SHOOK N OF SANDYS TRACK IN THE POUNDING NE FLOW. AM EXPECTING A 10.5 TO 12.0 MLLW EVENT THERE. THAT IS A 6 TO 7 FOOT SURGE…WELL OVER PRIOR FLOOD OF RECORD /DONNA 10.1 SEPT 12 1960/ AND WILL PROBABLY COINCIDE WITH THE HIGH TIDE. THIS WOULD PROBABLY BE DEVASTATING FOR PARTS OF NNJ REGION. IN ANY CASE WILL CALL IT A LIKELY FLOOD OF RECORD IN THE STATEMENT UNLESS OTHER TRACK GUIDANCE CHALLENGES THIS EXPECTATION. TO ESCAPE THE SEVERITY AT SANDY HOOK…SANDY EITHER NEEDS TO GO NORTH OF SANDY HOOK…ACCELERATE INLAND PRIOR TO 6 PM OR BE WEAKER BY 10 TO 20 MB.”
Obviously this will be the focus for my weathercasts again tonight.
Our next chance of rain will not be till next weekend with moderating temperatures this week, eventually back into the 70s.
Joe
