Amazing Ana: Uncharted Waters

Figure 1: Where exactly is the Central Pacific Basin? 

Figure 1: Where exactly is the Central Pacific Basin? 

As Ana continues to trudge north through the Central Pacific Hurricane Basin (Right: Black Circle), I wanted to dig up some past storms to use as some analogs to help predict what may happen over the next week.

Only one somewhat similar analog appeared after searching the historical storm database by NOAA and it revealed that destructive hurricane Iniki in 1992 is one of the only hurricanes that is remotely close to what Ana is attempting to accomplish during this week. It's also probable that Ana will be trekking over areas that have seen very little tropical activity since records have been kept. 

I find it quite comical and informative to contrast two hurricane basins, and the differences in activity  be warned, it's quite jaw-dropping:

Figure 2: Central Pacific Basin Historical tracks. There's no excellent analog for Tropical Storm Ana, which has traveled south of Hawaii as a hurricane and now is in the process of travelling due north, west of Hawaii.

Figure 2: Central Pacific Basin Historical tracks. There's no excellent analog for Tropical Storm Ana, which has traveled south of Hawaii as a hurricane and now is in the process of travelling due north, west of Hawaii.

Figure 3: Atlantic Basin Historical Tracks. Can you spot Florida? 

Figure 3: Atlantic Basin Historical Tracks. Can you spot Florida? 

To get a better idea where Ana is anticipated to end up, let's consult the experts at the National Hurricane Center:

Figure 4: Current tracks picked by the forecaster(s) shows Tropical Storm Ana sustaining tropical characteristics for the next 5 days before interacting with an approaching frontal system at around latitude 35N. This interaction will likely increase the amount of wind shear around the storm, making it quite a hostile environment to support a tropical storm

Figure 4: Current tracks picked by the forecaster(s) shows Tropical Storm Ana sustaining tropical characteristics for the next 5 days before interacting with an approaching frontal system at around latitude 35N. This interaction will likely increase the amount of wind shear around the storm, making it quite a hostile environment to support a tropical storm

Another common forecasting technique employs using individual ensemble members to help come up with a consensus; consequently, they indicate there's a very real possibility that the coast of BC will be affected by the remnants of Ana as early as next Monday.

But, as you can see below, there's a lot of uncertainty with regards to an exact track. One similarity worth noting: All models favor a specific re-curve (see figure 5) that may threaten the BC coast by hour 168. It's possible Ana will strengthen and regain hurricane status over the next 72 hours, which is being hinted at by the various hurricane models below:

Figure 5: GEFS Ensemble Guidance for ANA. GEFS Ensemble mean in Black, while GFS operational in Bue

Figure 5: GEFS Ensemble Guidance for ANA. GEFS Ensemble mean in Black, while GFS operational in Bue

Along with a track map forecast produced by the hurricane models, there's also a product that conveys the forecasted intensity which is also to be interpreted by expert forecasters to come up with an intensity official intensity forecast, as graphed in figure 6.  

Figure 6: Note the range of all the hurricane models. It's possible that Tropical Storm Ana will re-intensify into a hurricane for a 2nd time within the next 72 hours 

Figure 6: Note the range of all the hurricane models. It's possible that Tropical Storm Ana will re-intensify into a hurricane for a 2nd time within the next 72 hours 

Figure 7: Note the increase in forward speed after hour 120, as the cyclone undergoes transition to a typical northern latitude storm before crossing 40N. Cooler water temperatures and increasing wind shear with the approaching system from the NW will be the biggest factors in the weakening and the eventual demise of tropical storm status

Figure 7: Note the increase in forward speed after hour 120, as the cyclone undergoes transition to a typical northern latitude storm before crossing 40N. Cooler water temperatures and increasing wind shear with the approaching system from the NW will be the biggest factors in the weakening and the eventual demise of tropical storm status

Lastly, checkout out the super-ensemble the signal of Ex-Ana is alive and well. The deterministic European global model is currently an outlier tracking the cyclone into the Gulf of Alaska by day 7.  

Figure 8: NAEF plots for Tofino, BC hinting at Ex-Ana's presence 

Figure 8: NAEF plots for Tofino, BC hinting at Ex-Ana's presence