Hurricane Gustav…Which Way Will It Go? And What About Tropical Storm Hanna?


for a more recent update on Hurricane Gustav, CLICK HERE

Hurricane Gustav NHC Forecast Track 0829 5 pm

Hurricane Gustav NHC Forecast Track 0829 5 pm

I don’t have a lot to add to what I have said in the past. I still think that Hurricane Gustav has a good shot at perhaps being stronger than anticipated and doing so pretty quickly.

Hurricane Gustav Spaghetti Intensity Model Graph 0829 18Z

Hurricane Gustav Spaghetti Intensity Model Graph 0829 18Z

Its got a great looking outflow, has very warm water to work with and the western tip of Cuba won’t prove too disruptive. The National Hurricane Center forecast track is to the right of the general consensus of the modeling as indicated by the 18Z Hurricane Gustav Spaghetti Model. My suspicion of a stronger storm than anticipated is not supported by the Gustav Spaghetti Intensity Model graph. So, I’m a bit on a limb. It is unusual for the NHC to wander too far from the

Hurricane Gustav Spaghetti Model 0829 18Z

Hurricane Gustav Spaghetti Model 0829 18Z

consensus track. But, the fact that they have specifically said that and also outlined the other variables involved in the other forecast tracks which go farther west, then that indicates some uncertainty and, as they point out, this track should not be taken as Gospel and further review will be needed. The storm surge from this guy may be problematic depending on where it actually makes landfall and there are a number of indications that this guy gets stuck inland and could pose a major flooding threat well after landfall.

Don’t forget about Hanna. For days I had been pooh-poohing the storm as it developed. It appears that I was too quick because it didn’t move. Because it was so pokey, the environment has changed. Numerous models, as seen on the Hanna Spaghetti Model, indicate that this guy goes northwest and then gets forced down by ridging to the southwest. It is not out of the question that this storm, as indicated by the Hanna Spaghetti Intensity Model graph, becomes a formidable hurricane, moves across Florida and into the Gulf. Developing conditions make this scenario a very distinct possibility. So, we may be looking at two weeks of Hurricane action and all interests from Cape Fear to Corpus Christi need to keep up with tropical developments for the foreseeable future. Here is the Gustav Discussion followed by the Hanna Discussion and Hanna tracks and spaghetti models:

HURRICANE GUSTAV DISCUSSION NUMBER 20 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072008 500 PM EDT FRI AUG 29 2008 VISIBLE IMAGERY HAS OCCASIONALLY REVEALED AN EYE TRYING TO FORM…BUT THAT FEATURE HAS NOT BEEN PERSISTENT. NEVERTHELESS…THE CYCLONE CONTINUES TO INCREASE IN ORGANIZATION…WITH SOLID CONVECTIVE BANDS AND UPPER-LEVEL OUTFLOW THAT IS WELL-DEVELOPED IN ALL QUADRANTS. THE UNDERLYING WATERS OF THE NORTHWESTERN CARIBBEAN SEA ARE QUITE WARM…AND TO SOME DEPTH BENEATH THE SURFACE…SO THERE ARE NO APPARENT IMPEDIMENTS TO ADDITIONAL STRENGTHENING BEFORE GUSTAV REACHES WESTERN CUBA. EVEN RAPID INTENSIFICATION IS POSSIBLE…AS SUPPORTED BY THE LATEST SHIPS-BASED RAPID INTENSIFICATION INDEX THAT SHOWS A 35 PERCENT CHANCE OF AN INTENSITY INCREASE OF 30 KT OR MORE DURING THE NEXT 24 HOURS…SO IT IS POSSIBLE THAT GUSTAV COULD REACH MAJOR HURRICANE STATUS PRIOR TO CROSSING WESTERN CUBA. PASSAGE OVER CUBA WILL NOT LIKELY HAVE MUCH IMPACT ON THE STORM’S STRENGTH…AND ALL GUIDANCE FORECASTS A STRENGTHENING TREND OVER THE SOUTHERN GULF…WITH SLIGHT WEAKENING POSSIBLE IN THE NORTHERN GULF. THE OFFICIAL FORECAST AGAIN CALLS FOR A MAJOR HURRICANE OVER THE GULF…AND DESPITE THE WEAKENING IMPLIED BY THE LESSER INTENSITY OVER LAND AT 96 HOURS…GUSTAV COULD MAKE FINAL LANDFALL ALONG SOME PORTION OF THE NORTHERN GULF COAST AS A MAJOR HURRICANE. GUSTAV HAS TURNED MORE TO THE RIGHT AND SPED UP A LITTLE…NOW MOVING AT ABOUT 305/10…AS IT HEADS FOR A BREAK IN THE SUBTROPICAL RIDGE OVER THE EASTERN GULF OF MEXICO. THE PORTION OF THAT RIDGE THAT IS INTACT OVER THE SOUTHERN PLAINS OF THE UNITED STATES IS FORECAST BY ALL MODELS TO EVOLVE INTO A DEEP-LAYER HIGH THAT WILL REACH THE NORTHEASTERN U.S. IN A FEW DAYS. THERE ARE IMPORTANT DIFFERENCES AMONG THE MODELS…HOWEVER…IN HOW MUCH RIDGING WILL EXTEND SOUTHWESTWARD FROM THAT HIGH TOWARD TEXAS…AND IN HOW STRONG THE UPPER-LEVEL TROUGH CURRENTLY OVER THE CENTRAL GULF WILL BE OVER THE WESTERN GULF IN A FEW DAYS. THESE VARYING SOLUTIONS LEAD TO DIFFERENT TRACKS FOR GUSTAV OVER THE NORTHERN GULF. MODELS WITH THE RIDGE EXTENSION AND A STRONGER UPPER-LEVEL TROUGH WEST OF GUSTAV…SUCH AS THE NOGAPS AND UKMET…FORECAST GUSTAV TO TURN WESTWARD TOWARD TEXAS. OTHERS INCLUDING THE GFS…GFDL…AND HWRF…DO NOT SHOW THE RIDGE EXTENSION NOR A STRONG UPPER-LEVEL TROUGH…AND FORECAST GUSTAV TO BE PULLED INTO THE NORTHERN GULF COAST FARTHER EAST. THE NEW OFFICIAL FORECAST LEANS TOWARD THE LATTER SOLUTIONS AND IS EAST OF THE CONSENSUS…AND REPRESENTS NO SIGNIFICANT CHANGE TO THE PREVIOUS ADVISORY. DUE TO THE NOTABLE MODEL SPREAD LATE IN THE FORECAST PERIOD…IT IS ONCE AGAIN IMPORTANT TO RESTATE THAT IT IS SIMPLY NOT YET POSSIBLE TO DETERMINE EXACTLY WHERE AND WHEN GUSTAV WILL MAKE FINAL LANDFALL. FORECAST POSITIONS AND MAX WINDS INITIAL 29/2100Z 19.2N 79.7W 65 KT 12HR VT 30/0600Z 20.1N 80.9W 75 KT 24HR VT 30/1800Z 21.7N 82.8W 90 KT…OVER ISLE OF YOUTH 36HR VT 31/0600Z 23.4N 84.8W 100 KT 48HR VT 31/1800Z 25.2N 86.8W 110 KT 72HR VT 01/1800Z 28.0N 90.0W 105 KT 96HR VT 02/1800Z 30.5N 92.5W 85 KT…INLAND 120HR VT 03/1800Z 32.0N 94.0W 55 KT…INLAND $$ FORECASTER KNABB

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Tropical Storm Hanna Forecast Track 0829 5 PM

Tropical Storm Hanna Forecast Track 0829 5 PM

TROPICAL STORM HANNA DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082008 500 PM EDT FRI AUG 29 2008 THE CENTER OF HANNA REMAINS NEAR THE WESTERN EDGE OF THE RATHER SHAPELESS AREA OF DEEP CONVECTION SEEN IN SATELLITE IMAGERY. A 1412 UTC ASCAT PASS FOUND WINDS OF 40 KT OVER THE NORTHEASTERN SEMICIRCLE. GIVEN THE LOW BIAS TYPICAL OF ASCAT WINDS IN THIS RANGE…IT SUPPORTS MAINTAINING THE INITIAL INTENSITY AT 45 KT. THIS INTENSITY IS ALSO SUPPORTED BY SATELLITE ESTIMATES FROM TAFB AND SAB WHICH REMAIN T3.0 OR 45 KT. WATER VAPOR IMAGERY SHOWS THAT THE

Tropical Storm Hanna Spaghetti Intensity Model Graph 0829 18Z

Tropical Storm Hanna Spaghetti Intensity Model Graph 0829 18Z

UPPER-LEVEL LOW LOCATED A COUPLE HUNDRED MILES WEST-NORTHWEST OF HANNA HAS NOT BUDGED TODAY AND IT CONTINUES TO IMPART SOUTHWESTERLY SHEAR ON THE TROPICAL CYCLONE. THE DYNAMICAL MODELS REMAIN EMPHATIC SUGGESTING THAT THE UPPER-LOW WILL MOVE WEST OR WEST- SOUTHWESTWARD AND WEAKEN…ALLOWING HANNA TO

Tropical Storm Hanna Spaghetti Model 0829 18Z

Tropical Storm Hanna Spaghetti Model 0829 18Z

GRADUALLY STRENGTHEN. THE NEW NHC INTENSITY FORECAST CONTINUES TO ALLOW FOR SOME STRENGTHENING DURING THE NEXT COUPLE DAYS BUT SHOWS A LOWER PEAK INTENSITY THAN WAS FORECAST IN THE PREVIOUS ADVISORY. IN ABOUT 3 DAYS…THE MODELS CONTINUE TO FORECAST STRONG NORTHWEST TO NORTH UPPER-LEVEL WINDS OVER THE WESTERN ATLANTIC. THESE WINDS ARE PARTIALLY THE RESULT OF OUTFLOW FROM GUSTAV. DESPITE THE HOSTILE UPPER-LEVEL WIND FORECAST…THE INTENSITY GUIDANCE DOES NOT PREDICT WEAKENING. OUR INTENSITY FORECAST REMAINS ON THE LOW SIDE OF THE GUIDANCE AND STILL ASSUMES THAT THE NORTHERLY SHEAR WILL HAVE A NEGATIVE IMPACT ON HANNA’S INTENSITY. HANNA CONTINUES MOVING WEST-NORTHWESTWARD OR 295/9. IN GENERAL…THE FORECAST GUIDANCE HAS COME INTO A LITTLE BETTER AGREEMENT ON THE FUTURE TRACK OF HANNA. THE TROPICAL STORM IS FORECAST TO CONTINUE WEST-NORTHWESTWARD DURING THE NEXT 2 DAYS…FOLLOWED BY A TURN TOWARD THE WEST-SOUTHWEST. THE HWRF CONTINUES TO BE AN OUTLIER SHOWING A CYCLONIC LOOP NORTH OF THE SOUTHEASTERN BAHAMAS. THE NEW TRACK FORECAST IS VERY SIMILAR TO THE PREVIOUS FORECAST THROUGH 48 HOURS…BUT IS A LITTLE FASTER AND FARTHER WEST THEREAFTER. FORECAST POSITIONS AND MAX WINDS INITIAL 29/2100Z 21.8N 63.8W 45 KT 12HR VT 30/0600Z 22.8N 65.4W 50 KT 24HR VT 30/1800Z 24.0N 67.7W 55 KT 36HR VT 31/0600Z 24.8N 69.8W 60 KT 48HR VT 31/1800Z 25.0N 71.1W 65 KT 72HR VT 01/1800Z 24.5N 72.5W 65 KT 96HR VT 02/1800Z 23.7N 73.7W 60 KT 120HR VT 03/1800Z 23.0N 75.0W 60 KT $$ FORECASTER BROWN

4 Responses

  1. Pretty intense you guys..good job keeping us informed.

  2. Thanx, Jennifer. But unfortunately, the “you guys” is just me and my cats Nit and Wit…Snow White is not too amused at times when she wants to go sculling but I’m here pecking away. I must say though I have support from my colleagues at WLKY and have access to the WLKY weather center which is great. We’ve got all sorts of stuff there. I just got contacted by someone in Cutoff, LA and I have folks in a newsletter that I put out that live all along the Gulf Coast…so I’m staying pretty much on top of this as best I can. I’ve lived everywhere from Houston to Tallahassee so I have particular interest in the area. I can assure you that me and my “staff” will continue to do the best we can.

  3. Thank you for your in-depth and current updates and analysis. You are the level head that I’ve been looking for. I live in New Orleans and am leaving tomorrow to points northeast. Thanks again!

  4. Thanx Phil. I’ve got family in New Orleans…the place of my birth! And I”ve got lots of friends all over Cajun Country. Be careful, the track is not set in stone and I don’t think will really show itself for a couple of days. But better safe than sorry.

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