2020 Atlantic Hurricane Season

[Windspeed]

Seasonal forecasts are beginning to make their way out from respected scientists in the field to media and news outlets. The majority of specialists are predicting a hurricane season with above-normal activity. ENSO looks to be swinging neutral to perhaps even a La Niña by July-September. Western Atlantic subtropical and tropical SSTs are running above average overall with some particularly noticeable 2-3°+C deviations in the GOM and W. Caribbean. Could 2020 be hyperactive? AMO and NAO may present both favorable patterns for not only hurricanes in the MDR, but potential land threats to the W. Caribbean and GOM as well this season. Bermuda-Azores ridging may also dominate the SER/WAR steering pattern during Cape Verde season. This might be a year where we even see a few long-trackers reach Central America.

 

[Windspeed]

Latest ENSO NMME forecast courtesy of@jaxjagman

NMME into fall

[Windspeed]

[Windspeed]

[jaxjagman]

Latest JAMSTEC,into summer

[Windspeed]

The prediction is for 19.8 +/- 4.4 total named tropical cyclones, which corresponds to a range between 15 and 24 storms, with a best estimate of 20 named storms. This prediction was made using the statistical model of Kozar et al. (2012, see PDF here). This statistical model builds upon the past work of Sabbatelli and Mann (2007, see PDF here) by considering a larger number of climate predictors and including corrections for the historical undercount of events (see footnotes).

 

The assumptions behind this forecast are A., the persistence of current North Atlantic Main Development Region (MDR) sea surface temperature (SST) anomalies (+1.1 °C in early to mid-April 2020 from NOAA’s Coral Reef Watch) throughout the 2020 hurricane season, B., the development of mild El Niño-Southern Oscillation (ENSO)-negative conditions by boreal late summer and early fall 2020 (ENSO forecasts here; we used mid-April 2020), and C., climatological mean conditions for the North Atlantic Oscillation in boreal fall/winter 2020-2021.

 

 If no La Niña develops, then the prediction will be slightly lower: 18.3 +/- 4.3 storms (range of 14-23 storms, with a best guess of 19).

 

Using an alternative model that uses "relative" MDR SST (MDR SST with the average tropical mean SST subtracted) in place of MDR SST yields a considerably lower prediction (13.6 +/- 3.7 total named storms). This alternative model also includes mild ENSO-negative conditions.

http://www.essc.psu.edu/essc_web/research/Hurricane2020.html

[Windspeed]

What are you thinking right now in terms of activity/numbers?

I am still working out my numbers. Where most seasonal forecasts are out and dependent upon neutral versus La Nina ENSO conditions, I am waiting just to bit, perhaps early May. The three major ENSO models should have better projections as region 3 begins to decline. I'd really like to know if we're going full Nina. Additionally, I'd like to know if +NAO is going to kick in big time and much earlier in the coming late Spring / early Summer period, or if that is going to oscillate virtually neutral as well. It's more than just projections of active versus hyperactive, but higher track nodes for the W. Caribbean or CONUS versus MDR and susceptibility to recurve.

[cptcatz]

Today's 6z GFS shows a system in the gulf on May 9, not developing but maybe?

[Windspeed]

Today's 6z GFS shows a system in the gulf on May 9, not developing but maybe?

With a -NAO, deep ECONUS trough and strong subtropical jet in place, anything that would/could develop in the GOM is going to be a very asymmetric heavily sheared mess. Would probably resemble a system much like a running coastal low or nor'easter. However, that could bring severe storms across Florida and the coastal Carolinas if there were to be any phase. At any rate, something to watch in the long-range.

[jaxjagman]

On 4/29/2020 at 11:46 AM, Windspeed said:

On 4/29/2020 at 9:58 AM, cptcatz said:

Today's 6z GFS shows a system in the gulf on May 9, not developing but maybe?

With a -NAO, deep ECONUS trough and strong subtropical jet in place, anything that would/could develop in the GOM is going to be a very asymmetric heavily sheared mess. Would probably resemble a system much like a running coastal low or nor'easter. However, that could bring severe storms across Florida and the coastal Carolinas if there were to be any phase. At any rate, something to watch in the long-range.THE G

Agree.The Euro this afternoon is even hinting at a Rex Block into the Bafffin Bay/Greenland in the long range the same time it looks to be a possible Kelvin Wave moving into GOM during wk.2 of May

[cptcatz]

Now the Euro is on board with possible development next weekend?

[Windspeed]

[Windspeed]

Region 3 is starting to nosedive. Looks like the precursor ENSO modeling has done really well this Spring as a La Niña does look to be developing....

 

[Windspeed]

[Rtd208]

Updated.

https://www.accuweather.com/en/hurricane/accuweather-issues-2020-atlantic-hurricane-season-forecast-update/735844?utm_campaign=AccuWeather&utm_content=&utm_medium=social&utm_source=facebook&fbclid=IwAR0dWgFtA9q6HHxTGLEtGiocaPQ30HdLGMmv74mWvuXG9358XPOBLh5nWp8

[cptcatz]

The GFS has consistiently been showing a pretty strong hurricane forming in the Pacific and making landfall in Central America.  Now the last two runs (May 8 00z and 06z) have it reforming in the Caribbean.  It'll be interesting to see if the models keep that up.

[jaxjagman]

Best chance of tropical genesis into the GOM would seemingly be more into June.Least today there could  be a Kelvin Wave moving into by some models along with the CFS across the Yucatan,this certainly would be a time frame to watch,BUT 3-4 weeks out is beyond trustworthy right now

[JakkelWx]

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1005 AM EDT Tue May 12 2020

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Special Tropical Weather Outlook issued to discuss the potential 
for subtropical development this weekend northeast of the Bahamas.

1. 1. An area of low pressure is expected to develop this weekend 
a couple hundred miles northeast of the Bahamas. Environmental 
conditions appear conducive for this system to acquire some 
subtropical characteristics as it moves northeastward through 
Sunday. The next Special Tropical Weather Outlook on this system 
will be issued by 9 PM EDT Tuesday, or earlier, if necessary.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...50 percent.

Forecaster Latto

[cptcatz]

Looks like Arthur should be here in the next couple days...

 

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
240 PM EDT Thu May 14 2020

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Special Tropical Weather Outlook issued to discuss the potential 
for tropical or subtropical development near the northwest Bahamas. 

1. A trough of low pressure over the Straits of Florida is producing a 
large area of cloudiness and thunderstorms. Environmental conditions 
are expected to become conducive for development, and this system 
is likely to become a tropical or subtropical storm by late Friday 
or Saturday when it is located near the northwestern Bahamas. The 
system is then forecast to move generally northeastward over the 
western Atlantic early next week. 

Regardless of development, the disturbance has the potential to 
bring heavy rainfall to portions of the Florida Keys, southeast 
Florida, and the Bahamas through Saturday. Tropical-storm-force wind 
gusts are also possible in the Florida Keys, southeast Florida, and 
the Bahamas during the next day or two. Hazardous marine conditions 
are also expected along the Florida east coast and in the Bahamas 
where Gale Warnings are in effect. See products from your local 
weather office and High Seas Forecasts for more details. An Air 
Force Reserve Hurricane Hunter aircraft is scheduled to investigate 
this system tomorrow, if necessary. The next Special Tropical 
Weather Outlook on this system will be issued by 9 PM EDT today, or 
earlier, if necessary.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 percent.

High Seas Forecasts issued by the National Weather Service can be 
found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and 
available on the Web at ocean.weather.gov/shtml/NFDHSFAT1.shtml.

Forecaster Brown

[jaxjagman]

4 hours ago, WxWatcher007 said:

Just did a post on it in the Mid-Atlantic thread. Looks like that wave is very strong. Maybe something in the southern GOM or Caribbean late May/early June? 

Tropical genesis is hard to predict without a storm,it's just a time frame to watch right now possibly

[jaxjagman]

 

[Windspeed]

No surprise here.

That is NOAA though. Though SSTs may lag on rapid warmth due to the late swings in pattern, negative to positive NAO and positive AMO, -ENSO, etc., June looks amplified for strong favorable environmental gains to support an active TC setup in the western ATL basin by July. Might even see some W Caribbean / Gulf development into early June. Looks like an active to hyperactive season.

[Windspeed]

It has been a while since I’ve seen such an emphatic signal for an active season. Even without a niña breaking during the peak, a cool neutral regime is plenty favorable for an active basin. I do agree that this early June period looks good too. It’s in fantasy range but you can see a weak signal from the guidance starting to show up. 

 

I hate to April 27th a meteorological topic for hyperbole, but many of the characteristics of 2005 are coming into play with the late pattern swings here. That year saw a strong -NAO flip postive with a favorable AMO and ENSO for a hyperactive Atlantic. There are other variables, of course, not excluding WAM (West African Monsoon) and ITCZ suppression/placement along the surface wave-breaking entrance into the MDR and SAL. But with a +AMO and +NAO, a late shift like we saw in June that year gave us some incredible early fireworks out of the MDR as well. This year is going to be incredibly interesting to watch unfold.

[jaxjagman]

18 hours ago, WxWatcher007 said:

It has been a while since I’ve seen such an emphatic signal for an active season. Even without a niña breaking during the peak, a cool neutral regime is plenty favorable for an active basin. I do agree that this early June period looks good too. It’s in fantasy range but you can see a weak signal from the guidance starting to show up. 

 

CFS has been consistent with a Kelvin Wave and the MJO with it slowing down into the NH with the CHI posted above.This KW could spawn up some TG along the western flank if it's to be right into the first week of June,i'd keep watching along the Yucatan still upcoming

[jaxjagman]

GFS would have some potential for some TG into the GOM with the GYRE,Euro not as promising

[jbenedet]

Tropical disturbance near Florida, on the Gulf side would appear Lemon worthy....

[cptcatz]

Euro getting on board with a Gulf storm first week of June...

[jaxjagman]

There were a couple ensemble members of the GEFS 18Z which could lead into some TG into the GOM into June,to early to tell right now tho

[jaxjagman]

Seemingly there also looks to be a trough going through East Asia towards the end of the month,maybe something to watch as it could bring a CF toward the end of wk 1 of June in the east and also more trough in the NE,this could dampen out any TG expectations into the GOM

[cptcatz]

We now have four straight GFS runs (yesterday 18Z, today 00Z, 06Z, and 12Z) showing a big tropical storm in the Gulf on June 7.