Probability Surge Guidance

[rdale]

EFFECTIVE JUNE 1 AND CONTINUING THROUGH NOVEMBER 30 2010...THE
NWS IS SEEKING USER FEEDBACK ON EXPERIMENTAL TROPICAL CYCLONE
PROBABILISTIC STORM SURGE EXCEEDANCE PRODUCTS. THE EXPERIMENTAL
PRODUCTS WILL BE GENERATED WHEN A HURRICANE WATCH OR WARNING IS
IN EFFECT FOR ANY PORTION OF THE GULF OR ATLANTIC COASTS OF THE
CONTINENTAL UNITED STATES.

THE 10 THROUGH 90 PERCENT EXCEEDANCE PRODUCT SUITE WAS PROVIDED
AT 10 PERCENT INCREMENTS ON AN EXPERIMENTAL BASIS DURING 2009.
IT WILL REMAIN EXPERIMENTAL FOR 2010.

THE EXCEEDANCE HEIGHT IS THE STORM SURGE HEIGHT IN FEET...ABOVE
NORMAL TIDE LEVELS...SUCH THAT THERE IS AN N...WHERE N EQUALS 10
THROUGH 90...PERCENT CHANCE OF EXCEEDING IT.

THE PRODUCTS WILL BE POSTED ONLINE AT /USE LOWERCASE/:

HTTP://WWW.WEATHER.GOV/mdl/psurge

A COMPREHENSIVE DESCRIPTION AND STATIC EXAMPLES OF THE
EXPERIMENTAL EXCEEDANCE PRODUCTS ARE POSTED AT THE ABOVE
WEBSITE. GRIB2 AND ESRI SHAPE FILES WILL ALSO BE AVAILABLE AT
THIS WEBSITE BY CLICKING ON THE DOWNLOAD TAB.

GRIB2 FILES WILL BE TRANSMITTED ON NOAAPORT WITH THE FOLLOWING
WMO HEADERS:

LGXP10 KNHC 10 PERCENT CHANCE OF EXCEEDANCE
LGXP20 KNHC 20 PERCENT CHANCE OF EXCEEDANCE
LGXP30 KNHC 30 PERCENT CHANCE OF EXCEEDANCE
LGXP40 KNHC 40 PERCENT CHANCE OF EXCEEDANCE
LGXP50 KNHC 50 PERCENT CHANCE OF EXCEEDANCE
LGXP60 KNHC 60 PERCENT CHANCE OF EXCEEDANCE
LGXP70 KNHC 70 PERCENT CHANCE OF EXCEEDANCE
LGXP80 KNHC 80 PERCENT CHANCE OF EXCEEDANCE
LGXP90 KNHC 90 PERCENT CHANCE OF EXCEEDANCE

THE PRODUCTS WILL ALSO BE AVAILABLE IN GRIB2 ON THE NATIONAL
DIGITAL GUIDANCE DATABASE /NDGD/ AT /USE LOWERCASE EXCEPT
SL...ST...DF...DC...GT...AR/:

HTTP://WEATHER.NOAA.GOV/PUB/SL.US008001/ST.EXPR/DF.GR2/DC.NDGD/
GT.SLOSH/AR.CONUS

WITH FILE NAMES OF DS.SURGEEXCDNN.BIN WHERE NN IS THE EXCEEDANCE
PROBABILITY 10 THROUGH 90 PERCENT IN INCREMENTS OF 10.

USERS ARE ENCOURAGED TO PROVIDE FEEDBACK ON THESE EXPERIMENTAL
PRODUCTS BY USING THE BRIEF SURVEY AND COMMENT FORM AVAILABLE ON
LINE AT /USE LOWERCASE/:

HTTP://WWW.WEATHER.GOV/survey/nws-survey.php?code=phss
​

 

[MClarkson]

Do they really need that many? Wouldnt 10/50/90 be more reasonable. Would you even look at 80 if you had allready looked at 90?

 

[IAN GIAMMANCO]

I wonder how this is based? Slosh in real-time? I'm still for adding the surge destructive potential rating presented by Powell et al. 2008 into official forecast products.

 

[rdale]

Would you even look at 80 if you had allready looked at 90?

I'd be shocked if "people" looked at these - I think it's more for computerized algorithms and applications.

 

[Mike Gibson]

Why don't they send out a single GRIB2 file with the actual probability from 0-100%? Users of the file could create their own threshold masks/graphics from it.

Mike