Alastair Thompson Profile picture
Climate, Conflict, Politics, Africa. Editor https://t.co/b6HbxvlPDn (NZ) Reporting from France. https://t.co/LNVK0y9b2z #nzpol #DesertRain

Sep 30, 2022, 12 tweets

The NHC's forecasting for #HurricaneIAN remains tricky. Inching closer to the North/South Carolina border. And from satellite data, it looks possible that the center of #HurricaneIan is east of the current line.

The specialist HRRR model, which proved more accurate than the main models in predicting the path across Florida is now in agreement with ECMWF, GFS and NAM-CONUS on the location of landfall, but there is a broad range of intensity from 973-984 mb.

There is also a 6 hour range in arrival time among the four models from 1pm to 7pm. Due to the size of the storm, the impacts of #HurricaneIAN on the Carolinas & beyond are already well and truly underway over night local time.

So lets look at the satellite imagery. For this I am using the CMISS tool suite - an open source suite that utilises the live satellite floater data feeds - and highlights the important features - location and strength of convection and rotation.

Whilst #Hurricane Ian has strengthened a little the extent of the shear it is experiencing is very very high - which you can see as the center of circulation is only has convection to the north. Remarkably though it is still comitted to turning to the North West regardless.

From what I can discern the actual center of circulation is now considerably south of the the pointy cloud element on the LHS.

CONCLUSION: On that basis of this I think #HurricaneIAN is moving slower than expected - and East of where forecast therefore not on the current track. Landfall may therefore be further East of forecast in the direction of to Myrtle Beach/Wilmington.

Given this, I think it is important for the NHC to provide media with a live stream of accurate positioning data, as the graphics which have been broadcast throughout this storm since landfall in Florida, have often been wrong.

In this - latest live satellite image - it is clar that the storm is continuing to move north eastwards (the land is moving South West) and by now according to the track #HurricaneIAN is supposed to be moving North.

The Radar imagery here is a tell. #HurricaneIAN mayhave even stalled - which would explain its ability to develop rain bands in a circle - their appearance on sunrise also makes sense.

This is not good news as the longer the storm spends over water the stronger it is able to become. Its ability to do so whilst experiencing 50knots of shear is extraordinary.

The sun has not yet risen on #HurricaneIAN.

The first image shows the circulation location and size as indicated (approximately) by radar (4th image) .

2nd image shows the direction Ian is supposed to be going.

3rd shows position it is supposed to be in per the NHC forecast.

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