End of Hurricane Season - 2007

[dtel's wife]

GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO AS WELL...EXCEPT FOR THE GFDL. IT IS STALLING A MIDDLE-LEVEL LOW...CURRENTLY OVER THE BAHAMAS...IN THE EASTERN GULF OF MEXICO. THIS SOLUTION ALLOWS THE HURRICANE TO MOVE MORE TO THE NORTHWEST INTO THE CENTRAL GULF OF MEXICO. THIS SOLUTION IS CONSIDERED AN OUTLIER AT THIS TIME. HOWEVER...THE OFFICIAL FORECAST IS NUDGED A LITTLE TO THE NORTH AT 120 HR IN DEFERENCE TO THE GFDL FORECAST

While I realize all forecast models are considered when tracking/forecasting hurricanes, I am a little concerned about the GFDL model forecast track. It is usually one of the more reliable forecast models.

The GFDL "solution is considered an outlier at this time. However, the official forecast is nudged a little to the North...."

[CECAA850]

More than 300 forecasts were made for the Atlantic during the 2004 season, and the GFDL model proved to be either the best or next best in providing track guidance for forecasts from one to five days. In addition, more than 175 forecasts were made for the 2004 season in the Eastern Pacific, and the GFDL model proved to be the best track forecast model for periods from one to four days.

Not me, copy and pasted. It appears they're pretty good.

[Groomlakearea51]

CCAA and Dtel's "Minister of Finance"[]

That's the thing that woooories me about the GFDL super-ensemble. It is accurate (very much so...) for Day -4 through Day -0 (the moment of truth...). Hopefully, the GFDL track path past day four is not in agreement with everyone else. We'll have a very good idea on this by Sunday. Hopefully, it will be south of, rather than on top of Jamaica.

On that note, we're getting the "reverse" rain bands from the interaction from the high pressure trough boundary barreling down (to protect us from an early Dean right hand turn...). South Louisiana will be seeing some of the outlying south-north bands during the next 24-48 hours.

Here's a "simplified" surface analysis graphic (current)

[Groomlakearea51]

Surface analysis for 12 hours out:

[Groomlakearea51]

24 hours out:

[Groomlakearea51]

36 hours out:

[Groomlakearea51]

Dtel's wife:

You need to hope that high pressure ridge sits on top of you.......

[Groomlakearea51]

And 48 hours out:

[Groomlakearea51]

Unfortunately, if that high pressure area keeps moving, it allows the potential for the "wrap around"........

[Groomlakearea51]

Here's an interesting NHC graphic.... It's in the "For Really Stupid People Who Might Go There" category...... Note the statement on the right side....

[CECAA850]

Going back to the first graph, it looks like the CONU projection has been closest to being true so far.

[Groomlakearea51]

CONU is a compilation. It's a "consensus" ensemble computed when track forecasts from at least two of the five models (the NCEP GFS and GFDL models, the Navy's version of the GFDL model and NOGAPS, and the UK Met office model) are available. The CONU tries to take advantage of the ensemble forecasts even if one or a few of the members is not available. It was developed by James Goerss of the Naval Research Laboratory in Monterey, California.

Here ya' go... "Below is the track skill comparison" You are gonna love this!!! because the greatest error is the 24 to 48 hour level. Makes us all feel real confident!!!!!

[Groomlakearea51]

Now for a look at intensity (an important thing for those of us on the coast or with non-combat hardened bunker roofs)

[Groomlakearea51]

And for our friends and neighbors on the coasts..... Here's the SLOSH chart (I'm not kidding, this is what it's called...) Maximum surge possibilities....

[Groomlakearea51]

On the whole "accuracy thing" and the GFDL, some explanation of what that "super computer" ensemble is actually doing could be of some help.

GFDL - GHM Multiply-Nested Moveable Mesh Hurricane Model

The GHM is a dynamical baroclinic track prediction model. The model also produces experimental forecasts of hurricane intensity, precipitation, and wind swath maps that show the distribution of predicted maximum surface and boundary layer winds. The GHM was developed by NOAA's Geophysical Fluid Dynamics Laboratory (GFDL [8-|]) at Princeton University. .

The configuration of the GHM was most recently modified prior to the 2005 Atlantic hurricane season and the track skill improved substantially for all verification times. The new, coupled version of the model allows the sea surface temperature to evolve throughout a forecast integration. The evolution of the sea surface temperature can have a strong impact on the intensity of a storm. Previous uncoupled versions of the hurricane model essentially left the sea surface temperature constant throughout the duration of a forecast. Results have indicated that the ocean coupling has a positive influence on the skill of intensity forecasts .

[Groomlakearea51]

On the "Cone of Death", ever wonder why they always say "errors can be 250 nautical mileS by day 5"? Here's why:

James Goerss of the Naval Research Laboratory in Monterey, California, demonstrated that a simple consensus of the GFDL, UKMET and NOGAPS models was about 20% more accurate at 24, 48 and 72 hrs than the best of individual models. The National Hurricane Center confirmed his results and dubbed the ensemble "GUNS," using the initials of the three models.

[dtel's wife]

Groom,

Is this SLOSH chart updated for each hurricane? In other words is this the current SLOSH for Dean???????????

[dtel's wife]

The SLOSH chart sort of resembles the probability strike charts, but with storm surge forecast instead??????

[Groomlakearea51]

Meanwhile.... here's an extract from the latest.... Notes....: Finally, the French have decided that there really is a hurricane, rather than some weird American colonial panic propaganda program... If your French... Sorry, not picking on your ethnic heritage...... But IMHO it's a little late to make " Le Grand Announcement" when the beast is bearing down on you and it's been sorta' public knowledge for a couple days.....

AT 500 PM AST...2100 UTC...THE GOVERNMENT OF FRANCE HAS ISSUED A
HURRICANE WARNING FOR MARTINIQUE...GUADELOUPE AND ITS DEPENDENCIES.....

HURRICANE CENTER LOCATED NEAR 14.0N 56.5W AT 16/2100Z
POSITION ACCURATE WITHIN 20 NM

PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 20 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 979 MB
EYE DIAMETER 10 NM
MAX SUSTAINED WINDS 85 KT WITH GUSTS TO 100 KT.
64 KT....... 15NE 10SE 10SW 15NW.
50 KT....... 50NE 15SE 20SW 50NW.
34 KT.......120NE 75SE 60SW 130NW.
12 FT SEAS..300NE 90SE 60SW 150NW - (WATCH THIS!!!!)
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

[dtel's wife]

Dtel's wife:

You need to hope that high pressure ridge sits on top of you.......

Marshall,

We may be in trouble.....that high pressure has been "parked here for awhile now" odds are it's not going to hang around for another week?????

CCEA, are you paying close attention to these graphics??