2020 Atlantic Hurricane Season

[Windspeed]

The 40 days between Aug 20- Oct1 appears to be the main stretch in hurricane season.  Almost every active season has had above average ACE in that stretch.    
Really can't say much about the season by what happens before then.

Potential and modeling of all these variables are stacking up for it to really ramp up. I suppose you never know what will occur IRL until it happens, but it certainly looks concerning. Probably one of the biggest flashing exclamation points is the southerly prognosis of deep Caribbean runners with low shear. That has been modeled with consistency for several months. The large scale pattern supports that. Some of those could be big impacts for central America. But certainly having southerly tracking storms at that trajectory puts Florida and the GOM into play with any digging trough through the plains. Going to get interesting fo'sho.

[jaxjagman]

CFS shows a robust Rossby Wave moving into the Easten Pac,i can see why the gyre's dont show much of anything right now other than into the Eastern Pac.

[Windspeed]

Great discussion going on here... My take away, probably going to be plenty of lift across the basin regardless of the +IOD to make things go crazy from Aug. 20th into October.

 

[Rhino16]

I don’t see any of the strong lifting or sinking air over the atlantic in those if I’m reading them correctly, is that what they mean by “out of phase”? Do you want the rising air over the ocean, or a more neutral air movement somewhere in between as is shown in the images?

[Windspeed]

I don’t see any of the strong lifting or sinking air over the atlantic in those if I’m reading them correctly, is that what they mean by “out of phase”? Do you want the rising air over the ocean, or a more neutral air movement somewhere in between as is shown in the images?

You simply want to avoid sinking from height. This is counterintuitive to steeper lapse rates and CAPE needed to sustain convection for significant period of time to support TCG. However, it does not mean you cannot have a TC do well for itself if already developed. We have seen strong canes in an MJO suppressed phase, but typical when the TC had already gone through genesis. Strong upper vorticity helps TCG. But it is kind if meh as being proven to maintain intense hurricanes, which will have already superceded an atmospheric environment and SSTs, upper outflow pattern, wind shear and poleward velocities become of greater importance than MJO phase.

[Windspeed]

95L has been designated by TAFB. NHC has coded yellow and a 20% chance of development in 5 days. However, the environment is not necessarily unfavorable for development in the waves current location. It looks healthy, has a defined circulation, good convection and mid level vorticity, albeit still weak. I'd give this a better chance at TCG the next few days. It does not have the greatest model support atm, but the ECMWF ensembles do have it.

 

Edit: 95L, not 94L.

[Windspeed]

I think it’s 95L? Agree with the analysis though  
Guidance has been playing catch-up all season with TC genesis.

Yes, I meant 95L but typed 94L.

[Windspeed]

From 20% to...

Tropical Weather OutlookNWS National Hurricane Center Miami FL200 PM EDT Sun Aug 9 2020For the North Atlantic...Caribbean Sea and the Gulf of Mexico:Showers and thunderstorms associated with a tropical wave located a few hundred miles south-southwest of the Cabo Verde Islands continue to show signs of organization.  However, satellite-derived wind data from earlier this morning indicated that the circulation remains elongated.  Environmental conditions appear conducive enough to support additional development of this system, and a tropical depression could form during the next few days while it moves generally westward at 15 mph across the tropical Atlantic.  Conditions are likely to become less conducive for development late this week.* Formation chance through 48 hours...medium...40 percent.* Formation chance through 5 days...medium...50 percent.$$Forecaster Berg

[Windspeed]

Other models hate the wave. Go figure

Good thread on the lack of support. Right now it is in a moist bubble, but in a few days NW flow into a circulation could be quite a hindrance to continued intensification:

[Kevin Reilly]

95L. Has a vigorous mid level low but low level and mid level lows pretty far apart maybe it can get to the islands and pull an Isaias and relocate its centers.  
 You can clearly see the mid level circulation tuck under the thunderstorms at sun down out there. 

https://tropicaltidbits.com/sat/satlooper.php?region=95L&product=vis

[Orangeburgwx]

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[Prospero]

Waves off of Africa are the main focus, but what about storms that form in the Gulf of Mexico. Living on the Florida Gulf coast, seems like these are the ones that catch us off guard and throw us into a sudden preparation.

Do the models for this year suggest anything out of the ordinary?

The SST Anomaly is above average right now in a large part of the Atlantic.

But what about other factors beyond my limited knowledge?

 

 

[Orangeburgwx]

Waves off of Africa are the main focus, but what about storms that form in the Gulf of Mexico. Living on the Florida Gulf coast, seems like these are the ones that catch us off guard and throw us into a sudden preparation.

Do the models for this year suggest anything out of the ordinary?
The SST Anomaly is above average right now in a large part of the Atlantic.

But what about other factors beyond my limited knowledge?
 
 

Shear, SAL, dry air... Lots of factors

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[WEATHER53]

The last one survived strong shear so maybe it’s the year of shear survivors. 

[cptcatz]

From what I read, shear has decreased significantly and the only limiting factor now is dry air.

[WinterWolf]

54 minutes ago, cptcatz said:

From what I read, shear has decreased significantly and the only limiting factor now is dry air.

Well, if it’s going to be as active and anomalous as it’s predicted to be...then the shear and the dry air better be going away pretty soon!? 

[Jackstraw]

31 minutes ago, WinterWolf said:

Well, if it’s going to be as active and anomalous as it’s predicted to be...then the shear and the dry air better be going away pretty soon!? 

An average season of 10-12 has 2-3 named storms by now with 75% occurring over the next 6-8 weeks. This anomalous beginning is accounting for almost half of the very active season being forecasted. Since we already have 9, even and average Aug - Oct  would put us upwards of 20.  So it doesn't necessarily mean the tropics have to "blow up" soon in order to meet the current forecast.  A moderate above average Aug - Oct, say 10-12, as opposed to the Aug - Oct 8-10 average  could hit the threshold of some of the forecasts.  I think that's an important perspective.  We've almost got a 3rd of a high end 25 storm forecast in the bank by the first week of August.  Even an average or slightly below average Aug- Oct portion  will still put the entire season as well above average.  

So the question is, has the anomalous above average season being forecasted already occured?

Edit:  Just trying to point out that moving forward could be an average season in the timeframe left.  Some people may be disappointed if storm after storm doesn't start cranking soon and think the forecasts are off.  I'm putting odds on a normal, maybe slightly above normal Aug - Oct storm count.

 

[Floydbuster]

That wave is up to 60%. Stewart says it's getting better organized, which it clearly is. 

[Windspeed]

[wdrag]

Did anyone notice a very recent tweet from Eric Blake?  I can't access this on trop tidbits, but credit goes to Eric Blake, also apparently just promoted to Senior Hurricane Forecaster there. 

After August 20 a big change in shear across the Atlantic Basin.  It's an excellent hint at changes to come around the normal time of basin increase. I can delete this post if you wish. Just caught my attention on trop tidbits.  I can't move the loop over to this forum  but credit Trop Tidbits-Levi and Eric Blake. 

Really nice illustration of before and after the Madden-Julian Oscillation passage in the Atlantic from the GEFS-parallel. Note the initial high shear (red) in the deep tropics, then the late Aug transition to lower shear (blue) through the first part of Sep @TropicalTidbits

 

@EricBlake12

·

40m

 

Really nice illustration of before and after the Madden-Julian Oscillation passage in the Atlantic from the GEFS-parallel. Note the initial 

GIF

[Rtd208]

8 minutes ago, wdrag said:

Did anyone notice a very recent tweet from Eric Blake?  I can't access this on trop tidbits, but credit goes to Eric Blake, also apparently just promoted to Senior Hurricane Forecaster there. 

After August 20 a big change in shear across the Atlantic Basin.  It's an excellent hint at changes to come around the normal time of basin increase. I can delete this post if you wish. Just caught my attention on trop tidbits.  I can't move the loop over to this forum  but credit Trop Tidbits-Levi and Eric Blake. 

Really nice illustration of before and after the Madden-Julian Oscillation passage in the Atlantic from the GEFS-parallel. Note the initial high shear (red) in the deep tropics, then the late Aug transition to lower shear (blue) through the first part of Sep @TropicalTidbits

 

@EricBlake12

·

40m

 

Really nice illustration of before and after the Madden-Julian Oscillation passage in the Atlantic from the GEFS-parallel. Note the initial 

GIF

 

[Windspeed]

 

[SnoSki14]

15 hours ago, WinterWolf said:

Well, if it’s going to be as active and anomalous as it’s predicted to be...then the shear and the dry air better be going away pretty soon!? 

The tropics will likely flip like a switch. Even now despite unfavorable conditions we're still seeing invests try to spin up. 

I think we'll get our next storm shortly after the 20th (21-26 most likely). It's possible we get a rogue subtropical or brief MDR storm before then but our first big time storm won't come till late August.

We could see simultaneous storms in the 25th through September 15 time frame. A couple of them could be majors.

After the 15th there could be another lull but another active period in late September through October is very likely.

[Floydbuster]

I actually think we might well hit the Greek alphabet. That's something usually reserved for true weather weenies...but Dr. Klotzbach's forecast would bring us to Gamma, I believe. 

[Windspeed]

If Josephine forms in the next few days out of 95L, it's probably not going to survive much beyond the Lesser Antilles, regardless of short-term intensity changes. The outbreak of tropical activity and convection in the EPAC is going to really ramp up westerly upper level flow across the Caribbean and WATL as TUTTs form and retrograde. In fact, whatever might develop in the Atlantic over the next 10-12 days may struggle with shear. However, that being said, the MJO phases favorably over the basin the last week of August while coinciding with a sharp decrease in shear as the EPAC goes quiet. Perhaps a little sooner. But for now we seem to have some ammo against long-trackers over the next week. We still have to watch though in case some poor struggling sheared disturbance happens to find itself NE of the Antilles and an upper ridge builds.

[Maestrobjwa]

36 minutes ago, Windspeed said:

If Josephine forms in the next few days out of 95L, it's probably not going to survive much beyond the Lesser Antilles, regardless of short-term intensity changes. The outbreak of tropical activity and convection in the EPAC is going to really ramp up westerly upper level flow across the Caribbean and WATL as TUTTs form and retrograde. In fact, whatever might develop in the Atlantic over the next 10-12 days may struggle with shear. However, that being said, the MJO phases favorably over the basin the last week of August while coinciding with a sharp decrease in shear as the EPAC goes quiet. Perhaps a little sooner. But for now we seem to have some ammo against long-trackers over the next week. We still have to watch though in case some poor struggling sheared disturbance happens to find itself NE of the Antilles and an upper ridge builds.

Since apparently it's mandatory to always factor in the fact that it's 2020...bet on this happening at least once between now and late August, lol

[Baltimorewx]

Good chance we have Josephine today...fortunately, it appears likely it curves north of the islands and is of little threat to land. 

[Windspeed]

[Floydbuster]

It's gonna pop. People on different message boards are saying "things look quiet". Trust me, just wait.

This is one of the most favorable patterns of shear, sea surface temperatures, and MJO I've ever seen for late August through September. It's gonna blow.

[WinterWolf]

11 minutes ago, Floydbuster said:

It's gonna pop. People on different message boards are saying "things look quiet". Trust me, just wait.

This is one of the most favorable patterns of shear, sea surface temperatures, and MJO I've ever seen for late August through September. It's gonna blow.

You are stoked Floydbuster...we will see.