Jeff- I have a question for you

[ticka1]

In your hurricane prepardeness packet - you have a chart that represents the storm surge -why is it greater in the bays instead of along the coastline - can you explain why? I am sure its a simple explanation but I was just curious.

Category

Winds

(MPH)

Storm Surge Coast (ft) Bays

Damage

1

74-95

4-5 4-7

Minimal

2

96-110

6-8 8-12

Moderate

3

111-130

9-12 13-18

Extensive

4

131-155

13-18 19-24

Extreme

5

155+

18+ 24+

Catastrophic

[jeffl]

When a hurricane makes landfall, the surge is "funneled" into inland bays and inlets. The water is forced to rise as it is squeezed into a smaller more confined area where the sea level is not as deep.

For example, a surge of 12 feet on Galveston Island from the Gulf may be as high as 15-17 feet at the mouth of Clear Lake where water from Galveston Bay will be forced up the mouth of the creek. Surge values are also typically higher at the heads of bays and inlets and near the mouths of rivers and creeks where the surge is funneled.

[ticka1]

Thanks for your answer Jeff - I live approximately 4-5 miles from Trinity Bay here off FM3180 and FM565- since we are alot further inland - would the storm surge be realized in Trinity Bay or just Galveston Bay?

[jeffl]

Trinity Bay would have a significant storm surge. I need to know your elevation to know if you are above the surge zone. My suggestion would be to leave if a storm threatens to be on the safe side.

Emily should not create a significant storm surge along the upper Texas coast. Building wave action and Ekman transport will likely casue tides to run 1-2 feet above normal early next week. This may cause minor problems int he Kemah and Seabrook areas and along the western end of Galveston Island. Surge problems may be higher in and around Matagorda Bay where wave action will be at right angles to the coast. Significant surge is probable based on the latest NHC track over S TX including S Padre Island around the Port Isabel and Brownsville areas.

[BaytownWeatherWatcher]

I noticed the 11pm has us out of the cone. Is there any possibility at all that this storm will track higher up the coast or are we out of danger now and can relax? Thanks.

[Richblue2]

Speaking of which, do storm surges cause the same trouble with rivers as they do in bays?

Being originally from LA, there was always a lot of talk about New Orleans flooding, being below sea level and all.

Is this danger from the surge moving up the Mississippi, or actually washing that far inland?

I bet that would be an interesting thing, to observe a storm surge hitting the outbound water of a river. Might get quite choppy (as opposed to the wonderfully calm waters of a hurricane :s: )

[jeffl]

Speaking of which, do storm surges cause the same trouble with rivers as they do in bays?

Being originally from LA, there was always a lot of talk about New Orleans flooding, being below sea level and all.

Is this danger from the surge moving up the Mississippi, or actually washing that far inland?

I bet that would be an interesting thing, to observe a storm surge hitting the outbound water of a river. Might get quite choppy (as opposed to the wonderfully calm waters of a hurricane :s: )

It is a combination of both. For a landfalling hurricane passing to the SW and W of New Orleans, ESE winds will force the storm surge up the MS River and into Lake Pontchartrain. Both will overflow their banks and flood large sections of SE LA. Protection levees built around New Orleans will offer some protection to a certain point. If I am not mistaken I think anything above a Minimal cat 3 could overtop the levees.

So yes, storm surges cana nd and run up rivers. The land near the river is usually low (floodplain) and will be severely flooded by the surge.