2020 Atlantic Hurricane Season

[jaxjagman]

Global Tropics Hazards and Benefits Outlook Discussion

Last Updated: 05.26.20 Valid: 05.27.20 - 06.09.20

While an active intraseasonal signal is still present in the CPC velocity potential based MJO index as well as the RMM-based MJO index, the overall pattern has become increasingly incoherent over the past several days. The amplitude of the enhanced convective envelope in particular has decreased as a Kelvin wave propagated across the Pacific, well ahead of the rest of the signal. Despite the regime of enhanced trade winds across much of the Pacific basin, the Kelvin wave appears to be convectively coupled with the North Pacific ITCZ, and a zonally narrow band of anomalous westerlies is present south of Mexico. Dynamical model MJO index forecasts track this Kelvin wave better than any other coherent feature, with most model forecasts showing the signal returning to the Indian Ocean towards the end of Week-2 or weakening. Based on these recent observations and forecasts, a canonical MJO evolution from the Maritime Continent to the Pacific is not anticipated, but the Kelvin wave is likely to influence the tropical convective pattern, particularly across the Western Hemisphere. Cyclone Amphan made landfall over West Bengal on 20 May at Category-2 intensity on the Saffir-Simpson scale, causing considerable damage across northeastern India and Bangladesh. This single tropical cyclone generated more than double the climatological accumulated cyclone energy (ACE) observed over the North Indian Ocean basin during the entire Spring season. On 21 May, Tropical Storm Mangga formed over the South Indian Ocean. Following extratropical transition and merging with a cold front, the remnants of TS Mangga generated widespread wind damage across Western Australia. During Week-1, as the Kelvin wave crosses the East Pacific and with upper-level high pressure already in place, conditions will become increasingly favorable for tropical cyclone formation over the East Pacific basin. The NHC is monitoring an area just south of Mexico and Guatemala, and forecasts a 70-percent chance of a tropical depression forming in this region over the next 5 days. More GEFS ensemble members depict tropical cyclone activity at days 5-8 than days 1-4; therefore, there is high confidence for tropical cyclogenesis in this region during the Week-1 period. As the Kelvin wave progresses eastward, the favorable area is anticipated to expand to include the Gulf of Mexico and western Caribbean. Numerous GEFS ensemble members depict the formation of a tropical cyclone in this region, with a clustering of tracks bringing the potential cyclone towards the Florida peninsula, the northern Gulf Coast, or as far east as central Cuba and the Bahamas. There is a high degree of uncertainty regarding this forecast, and interests in the southeastern US, Mexico, and the western Caribbean should monitor the latest forecasts. A moderate potential for tropical cyclone formation is forecast for the Week-2 period extending from the East Pacific south of Mexico to the Bay of Campeche, southeastern Gulf of Mexico, and the far northwestern Caribbean. Elsewhere, dynamical models show a moderate potential for a disturbance west of India to become a tropical cyclone as it moves slowly northward across the Arabian Sea. Several GEFS ensemble members depict a second tropical cyclone formation near Oman; however, confidence is too low at this time to include a second Arabian Sea formation hazard on the outlook. Given the increasingly incoherent presentation of the intraseasonal signal, the forecasts for above- and below- normal precipitation are based on a consensus of bias-corrected CFS and ECMWF guidance, and potential tropical cyclone activity discussed above. Suppressed rainfall is favored across southeast Asia, the northwestern Pacific basin, and the equatorial central Atlantic during Week-1, while the central Maritime Continent and the East Pacific and western Atlantic basins are favored to be active. A disturbance near the US Southeast coastline may bring heavy rainfall to the Carolinas early in the period. A heat wave is ongoing across much of India, and is favored to continue early in the Week-1 period. Excessive heat is also likely across the US Southwest. During Week-2, suppressed rainfall is favored to continue over the northwestern Pacific region, while a moderate potential for enhanced rainfall shifts eastward across the Maritime Continent and the South Pacific, including American Samoa. An area of enhanced rainfall is possible over the western Indian Ocean north of Madagascar as the Kelvin wave returns to the Indian Ocean. While excessive heat is favored to diminish over India, a period of hot weather is possible across parts of Southeast Asia.

[OhioWX]

That looks like a tropical storm on KCLX. Observations from buoy 41004 are pretty compelling as well.

[thunderman]

Looks promising to me.  Would not be surprised as all to see advisories on TS Bertha initiated this morning.

 

[NorthHillsWx]

5 minutes ago, thunderman said:

Looks promising to me.  Would not be surprised as all to see advisories on TS Bertha initiated this morning.

 

Just named Bertha 

[Eskimo Joe]

 

[NorthHillsWx]

10 minutes ago, Eskimo Joe said:

 

With those years, how many had 2 purely tropical named systems (not sub-tropical storms as we frequently see in early season) before Hurricane season?

[Eskimo Joe]

 

[cptcatz]

I know this is hour 384 of the GFS (which means nothing), but this is quite a screenshot!

[JakkelWx]

ANOTHER AOI and it's only May 28th. Third one. 30/30. Chances are pretty low for development, and if development occurs, it will likely be subtropical in nature. Can you imagine if Cristobal formed right before June 1st, making it the third named pre-season storm? Either way, possibly a grim sign of what's to come during peak hurricane season.

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
725 PM EDT Thu May 28 2020

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

Special Tropical Weather Outlook issued to discuss the area of low 
pressure over the central Atlantic.

1. A surface trough and associated upper-level disturbance are 
producing disorganized shower activity and gusty winds over the 
central Atlantic Ocean several hundred miles east-southeast of 
Bermuda.  Gradual development of this system is possible, and it 
could acquire some subtropical characteristics on Friday and 
Saturday as it moves generally northward.  Development is not 
expected after that time due to unfavorable environmental 
conditions.  For additional information, see High Seas Forecasts 
issued by the National Weather Service. The next Special Tropical 
Weather Outlook on this system will be issued by 9 AM EDT Friday, 
or earlier if necessary.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...low...30 percent.

[thunderman]

NHC has bumped this newest AOI up to 50% now.

Quote

 

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
900 AM EDT Fri May 29 2020

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

Special Tropical Weather Outlook issued to discuss the area of low 
pressure over the central Atlantic.

1. A broad area of low pressure appears to be developing over the 
central Atlantic Ocean several hundred miles east-southeast of 
Bermuda.  This disturbance is producing a large area of showers and 
thunderstorms and gusty winds.  Additional development of this 
system is possible, and a subtropical depression could form tonight 
or on Saturday as it moves generally northward.  Development is not 
expected after that time due to unfavorable environmental 
conditions.  The next Special Tropical Weather Outlook will be 
issued by 9 PM EDT today, or earlier if necessary.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.

Forecaster Latto/Cangialosi

 

 

[jaxjagman]

23 hours ago, WxWatcher007 said:

Although the signal is still muddled, I think it is increasingly likely that we see tropical cyclone genesis in the western Caribbean or Bay of Campeche in the next ten days. Seems really important how this CAG manifests itself over the next few days. 
 

Seems like the best bet right now for TG would be towards the Gulf Shores to Texas next weekend.Today the Euro shows Ridging into the Northern Sea of Japan and then by tomorrow more into the Kuril Islands,so chances are you'd have troughing in the NE and another system heading in from the NW with heights pumping up from the Plains into the Lakes.most of the models show something similar right now anyways.

[jaxjagman]

Who knows right now.The control basically cuts it off but would be hitting some shear,big rain maker in parts of Texas either way if it were to be anywhere right.

[jaxjagman]

5 minutes ago, WxWatcher007 said:

The eps look more robust and ominous with stronger lows in the Gulf. Definitely perked up here with the growing potential. 

Need a banter thread because this is where it belongs.But look at the max QPFS into Texas, bottom right from where the system  gets cut off. by the EPS.Would be insane  rain

[thunderman]

Getting really interested in what the next 7 days may hold in the Gulf.

 

[jaxjagman]

Yeah it seems to be dependant how the upper pattern evolves,certainly a chance

[jaxjagman]

[NavarreDon]

Up to 40% 48hrs & 50% 5 day


https://www.nhc.noaa.gov/xgtwo/two_atl_5d0.png


.

[Windspeed]

053112z ECMWF ensemble...

[Windspeed]

SSTs along the NW GOM are still relatively minimal 26-27°C to support an intense TC. However, if Amanda or newly named system's location is timed just right, a more favorable divergent upper pattern could be in place as it approaches landfall. Also SSTs may warm to 28°C by next weekend if cloud coverage/storminess clears out for the most part. We'll have to wait a few more days to see how the forecast ahead of any potential TC will be influenced by the synoptic and oceanic environment.

[jaxjagman]

1 hour ago, Windspeed said:

053112z ECMWF ensemble...

A few members are showing a stronger system compared to yesterday

[jaxjagman]

EPS Control breaks down the Mid level ridge faster today and the storm is more progressive as it gets into Texas.But still aims towards East Texas.It's just some guidance at this point

[NavarreDon]

.

[jaxjagman]

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
750 PM EDT Sun May 31 2020

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

Special Tropical Weather Outlook issued to discuss the potential for 
tropical cyclone formation over the southwestern Gulf of Mexico.

1. The remnants of Eastern Pacific Tropical Storm Amanda are currently 
located over northern Guatemala.  This system is forecast to move 
northwestward to northward within a broader area of disturbed 
weather, and it could emerge over the southeastern Bay of Campeche 
on Monday. If the remnants move back over water, environmental 
conditions appear conducive to support some development, and a new 
tropical depression could form while the system moves little through 
the middle of this week. Regardless of tropical cyclone formation, 
heavy rainfall is likely to continue over portions of southern 
Mexico, Guatemala, El Salvador, Belize, and western Honduras during 
the next few days. For additional information on the rainfall 
threat, see products from your national meteorological service.  The 
next update on this system will be in the first regularly scheduled 
Tropical Weather Outlook of the 2020 Atlantic Hurricane season, 
which will be issued by 2 AM EDT Monday morning.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...60 percent.

Forecaster Beven

[jaxjagman]

The Upper Level ridge made it to the Kuril Islands today,The track into next weekend should be dependant on how strong a Mid level ridge is and how fast it possibly could get broke down or not,least that's my thinking right now

[NavarreDon]

We have a cherry.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Mon Jun 1 2020

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

1. The remnants of Eastern Pacific Tropical Storm Amanda are currently 
located inland near the Guatemala-Yucatan Border.  This large 
disturbance is forecast to move slowly northward this morning, 
followed by a northwestward motion later today, and the center of 
the low pressure system could emerge over the southeastern Bay 
of Campeche by this evening. If the remnants move back over water, 
environmental conditions appear conducive to support some 
development, and a new tropical depression could form while the 
system moves little through the middle of this week. Regardless of 
tropical cyclone formation, heavy rainfall is likely to continue 
over portions of southern Mexico, Guatemala, El Salvador, Belize, 
and western Honduras during the next few days. For additional 
information on the rainfall threat, see products from your national 
meteorological service.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...70 percent.

[jbenedet]

11 hours ago, NavarreDon said:

.

We have a -NAO/ -AO pattern developing in the eastern CONUS—synoptic scale troughing will predominate. I’m thinking sell the tracks into Texas, and look from central LA coast to panhandle Fla as biggest risk. Also hedge on the faster/more progressive side of guidance...6z GEFS really picking this up...

[LansingWeather]

Looks like the broad circulation center (as best I can tell) is just now hitting the BOC. Will be interesting to see how fast convection fires up and the circulation tightens back down.

[Windspeed]

Might the African wavetrain get an early start this year?

[LansingWeather]

We officially have Tropical Depression 3. :lkely to be TS in 24hrs

 

https://www.nhc.noaa.gov/

[cptcatz]

I know it's way down the line but the GFS has consistently shown on multiple runs another storm forming in the western Caribbean around June 17.  The GFS did a great job forecasting Cristobal from about the same time out, so it could be another one to watch.