Jack Wales

Hi SB, from looking at the CPC chart, the stratospheric temperature is currently fairly neutral. If anything it is just emerging from a cool phase between 2 - 10 hpa. Stratospheric Temp Anomaly What we need to see is intense warming from the upper level which then propogates down to the lower layers thus displacing the cold arctic air southward and possibly in our direction. With a six week lag for this effect to be realised at the surface, we need to see this before the end of December IMO. Here is the chart from 1987.. 1987 Chart

Yes, 93L has developed substantially over the last few hours. There is convection bursting all around the centre, the perviously open quadrant on the eastern flank has closed up nicely. With the good banding forming, I would not be surprised to see 93L go straight in as a Tropical Storm...

As I see it 97L is already a TD possibly a TS with strong convection/circulation, low shear and banding... However with shear affecting its path to the north or north-west unless the system follows a westward course it could be another Josephine. As for 98L, I agree with SS in that it has a bit of work to do yet, but with warm SST's and low shear forecast in the medium term prospects for significant strengthening are better than 97L.

Ike certainly has the pressure to bomb but is being inhibited by dry air IMO. If the eyewall can get itself sorted it could strenghthen a bit dut with the dry air making inroads I think it'll stay as a cat 2.

Yes we do get the tail end of hurricanes, so in a nutshell... Atlantic hurricanes form in the tropics and generally head east to west across the Atlantic towards the USA/Caribbean under the mid Atlantic ridge. As they reach the western side of the tropical Atlantic sometimes they curve northwards skimming or missing the US Eastern Seaboard. By this point the hurricanes are over coolers seas so are unable to maintain their energy levels plus they also tend to merge with frontal systems and get picked up by the Polar Jet stream sending them back on a westward course towards us. Although by this point the hurricanes have turned extra-tropical (lost their tropical characteristics i.e. eye-wall, warm core et al) they can still develop into potent low pressure systems. As for October 1987, this was not a hurricane in any way shape or form, the winds were not hurricane strength (sustained at 74mph for over a minute). In fact Britain is exposed to strong winds regularly during Autumn/Winter equal to the 1987 event however such synoptics normally hit the west/north where the landscape is more attuned to such conditions or it is deemed less newsworthy.

Josephine seems to have come back from the dead overnight with new convection bursting all over her, she is still being heavily sheared from the SW but with the additional convection she has a better chance of making it past 72 hours when conditions become more favourable.

Hi both, thanks for that info re those winters, it just shows the difference it can make when the polar air had less time to be moderated by the sea. As you say we never see ice-days in low lying parts from northerlies any more so I was surprised by -2.7 as a max in Lancaster. It does appear that last years minima is under threat although one subtle difference I've noticed is that the greater losses are being seen on the 'other side' of the arctic this year, with slightly better (although still below average) retention in the greenland sea and barents sea than in 2007.

I'm intrigued by this one, as SS says an eye already apears to be forming, so with good convection, 29C sst's and no shear, Jospehine could get up to Cat 2 in the short term. If so she will be better poised to resist the progged shear and lower SST's later in the timeframe.

Extremely unlikely as the ridge is keeping Ike on a westward track towards the Caribbean. NYC is not immune from hurricanes although they are rare and normally weaken somewhat before landfall due to lower SST's and in some cases becoming extratropical. Whilst a storm surge in these areas would not be welcomed it would not cause damage on the same scale as New Orleans due to higher ground elevations.

Took the words out of my mouth SS! Just been browsing the sat images and the eye appears to have formed already although it's still slightly open at the southern side.

The flat westward track is forecast due to the strong ridge progged to build across the W Atlantic thus blocking any poleward movement. Having said that Hannah has surprised everyone with her track in the immediate timeframe so IMO it's far to early to call a landfall for Ike on any particular country as yet. Interestingly the UK Met has forecast less ridging allowing a more nw'ward curve later in the timeframe, this has been dismissed by the NHC as an outlier but it's worth keeping an eye to see if any of the other models come on board in the next day or so. Whatever happens, there is very little shear for Ike to contend with at the moment so it's very likely he will be a hurricane come this time tomorrow.

We now have TS Josephine!

Look at this live loop, you can clearly see Ike, TD10 and the queue of tropical waves coming off africa, could be an interesting month!

Hannah looking very sheared now and although the LLC can just be detected over the bahamas, all the convection has been displaced well to the south and IMO she is now at risk of being sheared apart.

You're correct Kold, downgraded to TS at the moment but should regain hurricane status within 24 hrs as shear levels drop... NHC Hannah From NHC... 000 WTNT33 KNHC 021156 TCPAT3 BULLETIN TROPICAL STORM HANNA INTERMEDIATE ADVISORY NUMBER 22A NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082008 800 AM AST TUE SEP 02 2008 ...HANNA WEAKENS TO A TROPICAL STORM... ...HEAVY RAINFALL AFFECTING THE SOUTHEASTERN BAHAMAS...TURKS AND CAICOS ISLANDS...AND HAITI... A HURRICANE WARNING REMAINS IN EFFECT FOR THE CENTRAL BAHAMAS...THE SOUTHEASTERN BAHAMAS...AND THE TURKS AND CAICOS ISLANDS. INTERESTS ALONG THE NORTH COAST OF HAITI...EASTERN CUBA...THE NORTHWEST BAHAMAS...AND THE FLORIDA PENINSULA SHOULD MONITOR THE PROGRESS OF HANNA. FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL WEATHER OFFICE. AT 800 AM AST...1200Z...THE CENTER OF TROPICAL STORM HANNA WAS LOCATED NEAR LATITUDE 21.2 NORTH...LONGITUDE 73.1 WEST OR VERY NEAR GREAT INAGUA ISLAND AND ABOUT 385 MILES...615 KM...SOUTHEAST OF NASSAU. HANNA IS DRIFTING TOWARD THE WEST NEAR 2 MPH...4 KM/HR. SLOW AND ERRATIC MOTION IS EXPECTED TODAY. HOWEVER...HANNA IS EXPECTED TO BEGIN MOVING NORTHWESTWARD TONIGHT AND WEDNESDAY. ON THE FORECAST TRACK...HANNA WILL MOVE OVER THE SOUTHEASTERN BAHAMAS TODAY AND INTO THE CENTRAL BAHAMAS TONIGHT AND WEDNESDAY. MAXIMUM SUSTAINED WINDS HAVE DECREASED TO 70 MPH...110 KM/HR...WITH HIGHER GUSTS. ALTHOUGH LITTLE CHANGE IN STRENGTH IS EXPECTED DURING THE NEXT 24 HOURS...HANNA COULD REGAIN HURRICANE STRENGTH LATER TODAY OR TOMORROW. TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES...280 KM. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB...29.15 INCHES. HANNA IS EXPECTED TO PRODUCE RAINFALL AMOUNTS OF 8 TO 12 INCHES... WITH ISOLATED AMOUNTS OF 20 INCHES...OVER THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS. AMOUNTS OF 4 TO 8 INCHES...WITH ISOLATED MAXIMUM AMOUNTS OF UP TO 12 INCHES...ARE EXPECTED IN THE CENTRAL BAHAMAS. RAINFALL AMOUNTS OF 2 TO 4 INCHES WITH MAXIMUM AMOUNTS OF UP TO 8 INCHES ARE EXPECTED OVER THE MOUNTAINOUS TERRAIN OF EASTERN CUBA AND NORTHERN PORTIONS OF HISPANIOLA...WHERE THESE RAINS COULD CAUSE LIFE-THREATENING MUDSLIDES AND FLASH FLOODING. COASTAL STORM SURGE FLOODING OF 3 TO 5 FEET ABOVE NORMAL TIDE LEVELS...ALONG WITH LARGE AND DANGEROUS BATTERING WAVES...CAN BE EXPECTED IN AREAS OF ONSHORE FLOW WITHIN THE HURRICANE WARNING AREA. SWELLS FROM HANNA ARE EXPECTED TO INCREASE THE RISK OF DANGEROUS RIP CURRENTS ALONG PORTIONS OF THE SOUTHEASTERN UNITED STATES COAST DURING THE NEXT COUPLE OF DAYS. REPEATING THE 800 AM AST POSITION...21.2 N...73.1 W. MOVEMENT TOWARD...WEST NEAR 2 MPH. MAXIMUM SUSTAINED WINDS...70 MPH. MINIMUM CENTRAL PRESSURE...987 MB. THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT 1100 AM AST. $$ FORECASTER RHOME/FRANKLIN

Intriguing to see how far south the ice extended in 1968 with the entire north of Iceland locked in with ice, I bet that made any northwesterlies quite potent in Iceland during this time. Sadly it will take something special to bring about a repeat of such events any time soon, especially now that we appear to be heading towards last years minima...

The centre is still about 150 miles away from the Dominican as is the deepest convection so your mum should be ok. Hannah seems to be static at the moment but an upper low to the west should turn her back northwards again tomorrow.

I think Hannah is just far enough away to avoid being affected by the outflow from Gustav, she's still experiencing northerly shear but hanging in there. Latest from NHC...

I wouldn't say better organised plus with very strong northerly shear progged over the region, Hannah's future is very much in the balance at the moment. If she can get through the next two days or so without being sheared apart then conditions should be favourable for rapid strengthening.

Ironically this could help inhibit any further strengthening, with a fast nothwestward motion coming up against northerly shear, I think it could end up making landfall as a Cat 2. Although as Kold says, it's not so much the wind speed but the size of the hurricane that will do the damage.

To me the system looks to be stalling a bit at the moment, if so the land interaction with Cuba could weaken Gustav more than the NHC predict. However when it emerges over the GOM, I still fancy it to reach C5 with sst's of over 31C in places.

I doubt it as we are already approx 1/2m sq km from the 2007 minima. It looks as we are now approaching the 2008 minima from the graph on CT... Cryosphere Today NH Sea Ice Any further losses should be offset by gains in the high arctic although IMO it's still too early to completely rule out surpassing the 2007 minima.

Fay has definitely tightened up after stalling over the Atlantic, an eye appears to have formed although this has not totally cleared which to me indicates that the storm is very nearly at hurricane strength (probably 65 - 70mph)

Yes, I've rarely seen such a large track envelope for a tropical cyclone... 5 day track

Here are the models from the 15th... Models 15/8/08 Hi SB, I don't see how, I can't see a defined eye on that image.