Modellers discussing weak storm to come in US Gulf
General overview Monday 21st September 2015
Whilst conditions are continuing to prevent any incursion into the Gulf of Mexico from the east, there remains the slim possibility of a home grown system seizing an opportunity. Two respected modellers have been hinting at something developing in the Bay of Campeche, albeit over a week ahead. I struggle with giving long term forecasts any credence where frontal system are concerned as such forecasts tend to turn out to be a bit of a pig's ear, but barometric charts are starting to shape up. The hypothesis is based on the expectation that a broad area of low pressure is likely to form next weekend in the southern Gulf of Mexico. Anything that does develop is going to be subject to upper- level shear from the outset. Nonetheless, both the American and European modellers are discussing a week tropical storm making a brief appearance in the Gulf of Mexico in the middle of next week. The European modeller has this reaching weak tropical storm force before making landfall around the Mississippi, while the American modeller is being a little rasher and has this reaching storm force as it approaches the west coast of Florida, before making landfall in the panhandle area. Upper level shear will be the deciding factor on which, if either, of these forecasters brings home the bacon.
The remnants of tropical depression nine are centred around 800 miles north-nor'west of the Amazon delta and is fading as it moves away from the convergence zone, north-west at 8 knots. There are no signs of organisation and no further development is expected. This does appear as if it might be absorbed by IDA as both of them are hogging the Atlantic centreline.
IDA is centred around 200 miles slightly south of east of tropical depression nine, well clear of anywhere, really. This has become a little better organised, though most of the associated showers and thunderstorms are displaced to the east of the centre indicating the effect of upper level shear. Sustained winds remain around 45 knots. Little change in intensity is forecasted at the moment, however this is barely moving and environmental conditions are still quite favourable for this to ham up someone's day at sea. In the end, IDA will track north before accelerating and squealing off to the north-east.