Tropical Storm Isaac at 11 PM.. a list of questions..

11 PM

Still moving West. Still weak, though in the last half an hour he looks a bit better.

LOCATION...15.6N 55.6W
ABOUT 390 MI...625 KM E OF GUADELOUPE
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES

There are so many things to consider while watching Isaac try to pull himself together... still.

Though he is a Tropical Storm now, he is still weak and not showing a lot of color aka convection.

1. Hurricane Hunters are going in later tonight, so expect the 5am advisory and discussion to be more revealing.

2. Ironically, he carries a long band out in front of him that looks a lot like an elephant's trunk... hmmm.

3. Note the large frontal boundary draped across Florida and the SE extending into the Gulf.  That combined with the large high in the Atlantic is what will steer Issac towards Florida. Towards does not mean it hits any one city in Florida directly... towards Florida. The picture I posted last night remains the same set up... compare it with the satellite image above and the beeline models for Florida make more sense, don't they?

4. There is an ULL that is not visible on the IR but only on the WV loop. What that does and where that goes will also affect Issac down the road. ULLs are a love/hate thing... they provide shear, they also help steer the storm. Why I have read so little in discussion on Isaac on this ULL I don't know but it has my attention. It's digging down from the Bahamas over Cuba.



5. The story is not where Isaac is today but where he is in a few days. Does he hit Haiti? Does he miss Haiti? Which part of Cuba does he traverse? Some areas have more mountains, some are wider, thicker. Worst case scenario would be to clip the SE corner of Haiti and curve up across Gitmo or further to the West where Cuba is very narrow.



6.  San Juan, PR is just to the north of the track of Isaac. If there is any variation of this track they will deal with this storm more directly. Keep watching the discussion out of PR: NOTE at 11pm a Hurricane Watch was posted for PR...so wondering if confidence is low on the forecast for it to stay to the south or PR.

http://forecast.weather.gov/product.php?site=NWS&issuedby=SJU&product=AFD&format=CI&version=1&glossary=1

7. Model discussion and the NHC translation of the models.  The 11 PM discussion that just came out does mention the Upper Level Low that has been bothering me. It also mentions the topographical intangibles that cannot be answered just yet. Also, it is worth noting they are going with the HWRF and I suppose waiting to see what the planes find and what the next run of the GFS shows. They like consistency.

"VAPOR IMAGERY SUGGESTS THAT EAST-NORTHEASTERLY SHEAR IS

CURRENTLY AFFECTING ISAAC...BUT THE DYNAMICAL GUIDANCE PREDICTS A
DECREASE IN SHEAR WITH UPPER-LEVEL ANTICYCLONIC FLOW OVER THE
TROPICAL CYCLONE DURING THE NEXT SEVERAL DAYS.  THEREFORE
STRENGTHENING IS ANTICIPATED...AND ISAAC COULD BECOME A HURRICANE
WITHIN THE NEXT COUPLE OF DAYS.  LATER ON...THE INTENSITY FORECAST
IS COMPLICATED BY HOW MUCH THE CORE OF THE SYSTEM INTERACTS WITH
THE MOUNTAINOUS LAND MASSES OF HISPANIOLA AND EASTERN CUBA.  THE
OFFICIAL WIND SPEED FORECAST IS FAIRLY CLOSE TO THE STATISTICAL-
DYNAMICAL GUIDANCE FOR THE FIRST 48 HOURS AND THEN TRIES TO TAKE
INTO ACCOUNT THE LAND INTERACTION."

and...

"ALTHOUGH THE GFS HAS SHIFTED JUST A BIT TO THE

NORTH OF ITS PREVIOUS FORECAST...OVERALL THE TRACK GUIDANCE HAS NOT
CHANGED MUCH SINCE THE PREVIOUS CYCLE.  THE OFFICIAL FORECAST IS
VERY CLOSE TO THE LATEST HWRF TRACK AND NOT FAR FROM THE DYNAMICAL
CONSENSUS."

 8. I cannot stress how each storm is different from the previous year's storms. It's nice for Cantore to talk on Irene but the set up was different last year from this year. And, as much as I wax poetic about Cleo... this year is different, although it was a similar set up. So... wait and see what Isaac to look like tomorrow. It is may I add almost chilling that the models continue to track this storm right up to South Florida's front door.  Cantore thinks it will go to the west/south. My son who is studying Computer Engineering at Iowa State keeps pointing out the very hot water in the Gulf and worries on Isaac missing the Florida scenario. Then again, Garrett Bastardi makes a very good case for a miss to the right and a track off shore and up into the Wilmington NC area.. or south. My best friend Sharon also wants to know how it gets west of 78 W but she is also going with climo and history. This storm keeps going west and until it bends a little.. models will pull west.

http://firsthandweather.com/blog/all-posts/tropical-storm-isaac-approaching-lesser-antilles

9.  Timing is intricately linked to intensity. Everything is timing in life from who you end  up with or don't end up with, whether you get that hot pair of heels in your size or someone else does, whether it rains on your wedding day or is sunny and bright. Everything is timing. And, it's a matter of whether the front comes down fast or slow. Whether the high holds tight or begins to nudge away. Whether it hovers over Tampa on Monday at 9PM the way the GFS model is currently predicting. It's all a matter of timing.  The GOP has been extremely quiet on what it's Plan B is ... inquiring minds want to know.

10.  Where does Jim Cantore go?  He claims not to know ;) People do look at the oddest things.

For now... my favorite map of choice is the Navy map from the NRL. Note that map updates faster than the NHC map... I always go with the NRL and what it hints at on each revision.

So that's my thoughts on Isaac at 11 PM on Tuesday. There will be better info tomorrow and we will see on radar as he passes though the islands what he really looks like.

Lastly......................where is he going AFTER Florida??

Though the short term has not changed much, earlier in the day most of these tracks were offshore in the Atlantic through the Carolinas.. up towards the Mid Atlantic.. now the long term tracks seem more inland over various parts of the US. That may be a telling sign..

Keep watching...


Sweet Tropical Dreams