ATL: ALEX - Post-Tropical

[MGC]

Alex looks as impressive as a mid season hurricane. First satellite pictures of a Atlantic hurricane in history!. There goes my 2016 seasonal prediction,,,,MGC

[CrazyC83]

If I recall correctly, the Nor'easters in January 1992 and at Christmas in 1994 may have had a similar structure and synoptic setup? Mother Nature sure can amaze.

[Exalt]

Everyone kept doubting this storm but I had an inclination from the start that Alex would fully transition.

[chaser1]

Could we get a minimal Cat.2 hurricane before all is said and done?

Who said the Atlantic would never out-produce the Pacific in tropical development during a major El Nino event In all seriousness though, I'm dumbfounded at how impressive Alex appears that far north and given the SST's. Upper dynamics aside, it just sounds bizarre to discuss Atlantic hurricane development and 20C SST in the same sentence. In one of the threads a couple months ago I had pondered that we might see an additional "out of season" storm develop, but was likely thinking a lower latitude T.S. rather than a hurricane that was closer to the North Pole than the equator.

[Alyono]

Could we get a minimal Cat.2 hurricane before all is said and done?

Who said the Atlantic would never out-produce the Pacific in tropical development during a major El Nino event In all seriousness though, I'm dumbfounded at how impressive Alex appears that far north and given the SST's. Upper dynamics aside, it just sounds bizarre to discuss Atlantic hurricane development and 20C SST in the same sentence. In one of the threads a couple months ago I had pondered that we might see an additional "out of season" storm develop, but was likely thinking a lower latitude T.S. rather than a hurricane that was closer to the North Pole than the equator.

The only real thing unusual about this is that it happened in the Atlantic this time of year. Last year in the winter (or maybe late fall), this occurred in the Mediterranean, which is where I would have expected any January development to occur

[WeatherGuesser]

Guess the pool for when the first will form is unnecessary, eh?

[terstorm1012]

If I recall correctly, the Nor'easters in January 1992 and at Christmas in 1994 may have had a similar structure and synoptic setup? Mother Nature sure can amaze.

yes, there was a weatherwise article about it years and years ago. I wish I could remember the year so I could find it again.

[1900hurricane]

Could we get a minimal Cat.2 hurricane before all is said and done?

Who said the Atlantic would never out-produce the Pacific in tropical development during a major El Nino event In all seriousness though, I'm dumbfounded at how impressive Alex appears that far north and given the SST's. Upper dynamics aside, it just sounds bizarre to discuss Atlantic hurricane development and 20C SST in the same sentence. In one of the threads a couple months ago I had pondered that we might see an additional "out of season" storm develop, but was likely thinking a lower latitude T.S. rather than a hurricane that was closer to the North Pole than the equator.

I know the point you're making, but when Alex first became a hurricane at 12Z, it was at 30.8*N, which is almost twice the distance to the pole (90*N) than it is to the equator (0*N).

Anyway, tops in Alex are starting to creep below -60*C in places. Very impressive.

[terstorm1012]

there's a thread on the 1994 Christmas Nor'easter actually! viewtopic.php?f=22&t=16850

[1900hurricane]

Looking at the structure I would say it is T5.0, but the cold boundary layer may prevent the strongest winds from reaching the surface. Still 80 kt seems reasonable with 85 kt possibly justifiable as well.

I don't think a cold boundary layer is an issue right now. While more shallow than in the tropics, Alex is very clearly generating convection the way any other tropical cyclone would, through the warm and moist air (relatively speaking in this case) from the ocean through the boundary layer. Compared to the cold air aloft, the boundary layer is plenty warm.

[cycloneye]

HURRICANE ALEX DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012016
500 PM AST THU JAN 14 2016

Alex has been maintaining a fairly impressive appearance on
satellite imagery, with a well-defined 15-20 n mi diameter eye
embedded within cold cloud tops. Recent images do suggest some
warming/erosion of the tops over the southwest quadrant. Dvorak
T-numbers remain near 4.5 so the current intensity is held at 75
kt. Sea surface temperatures are now below 20 deg C and should
continue to cool along the path of Alex. This, along with a little
increase in southwesterly shear, should result in gradual
weakening. However, Alex is expected to maintain hurricane strength
while passing near or over the Azores. In 24 hours or so, the
global models show a distinct warm front over the northeast portion
of the circulation. This suggests extratropical transition, and the
official forecast reflects this. Later in the forecast period, the
global models show the system merging with another extratropical
cyclone over the northern Atlantic.

The initial motion is slightly east of due northward or 015/19.
There is essentially no change to the track forecast reasoning.
Alex continues to be steered by the flow of a shortwave
mid-tropospheric trough that has been rotating around a broader
trough to its northwest. This evolution should cause the cyclone
to turn gradually to the left with increasing forward speed over
the next couple of days. The dynamical track guidance models are
in excellent agreement for the first 36 hours of the forecast, and
the official forecast is near the consensus of these models. This
is basically an update of the previous NHC track prediction.

Alex's wind field is likely to expand as it nears and makes the
extratropical transition. The wind radii forecasts are based
primarily on guidance from the NOAA Ocean Prediction Center.

FORECAST POSITIONS AND MAX WINDS

INIT 14/2100Z 33.6N 27.8W 75 KT 85 MPH
12H 15/0600Z 36.4N 27.5W 75 KT 85 MPH
24H 15/1800Z 41.8N 27.9W 70 KT 80 MPH...POST-TROP/EXTRATROP
36H 16/0600Z 49.5N 29.7W 65 KT 75 MPH...POST-TROP/EXTRATROP
48H 16/1800Z 56.5N 34.0W 60 KT 70 MPH...POST-TROP/EXTRATROP
72H 17/1800Z...MERGED WITH ANOTHER EXTRATROPICAL CYCLONE

$$
Forecaster Pasch

[EquusStorm]

Beginning to elongate a little into a classic comma shape with the southern corner of the core starting to disorganize in the last few frames. Safe to say Alex could intensify more under baroclinic processes but the structure is a bit more messy than it was earlier.

[Alyono]

its peaked as a tropical system. However, as it accelerates, the winds east of the center should increase somewhat

[CrazyC83]

I'm thinking it peaked at 1200Z at 85 kt personally.

[Exalt]

I'm thinking it peaked at 1200Z at 85 kt personally.

Was it officially a Cat. 2?

[TimeZone]

Wow this is incredible.

[CrazyC83]

I'm thinking it peaked at 1200Z at 85 kt personally.

Was it officially a Cat. 2?

No it wasn't. But maybe in post-analysis?

[Hammy]

I'm thinking it peaked at 1200Z at 85 kt personally.

I think given the location and time of year they'll be very hesitant to classify it as such, but upping it to 90 in post analysis (which may very well come out before the season even starts) seems like a reasonable expectation.

[Alyono]

This has slowed down unexpectedly

[wxman57]

Looks like it's rapidly losing tropical characteristics.