Jump to content
  • Member Statistics

    17,609
    Total Members
    7,904
    Most Online
    NH8550
    Newest Member
    NH8550
    Joined

Atlantic Tropical Action 2013


Recommended Posts

  • Replies 2.2k
  • Created
  • Last Reply

Are you referring to the entire season? If so, the chances of us going without at least one major hurricane are incredibly slim. In fact, since 1851, it's only happened four times: the seasons of 1968, 1972, 1986, and 1994. In all four cases, there was an ongoing, strong El Niño. We're in a very La Niña-ish pattern.

 

 Excellent post. Not only that but a whopping ~55% of years since 1950 in the neutral negative to weak La Nina range have had an actual US major H hit! That's excluding 1974 (per Josh, Carmen's US hit will be downgraded from major) and 2005 (very close call and could have been counted as neutral negative depending on classification methodology.) This is vs. the only ~30% for other years (moderate to strong La Nina, neutral positive, and El Nino). The very cool first half of August, if anything, raises that chance even higher per analogs. I'm maintaining my prediction that the US will be hit by a major H sometimes this season. In reality, I think the chance is a solid 2 in 3.

Link to comment
Share on other sites

This should be an invest for sure not sure why the nhc hasnt yet either

 

The NHC does have it covered on their outlook. It probably will be invest worthy soon:

 

OTHER SYSTEMS WITH FORMATION POTENTIAL BEYOND 48 HOURS...

A TROPICAL WAVE LOCATED A FEW HUNDRED MILES SOUTHWEST OF THE CAPE

VERDE ISLANDS IS EXPECTED TO MOVE WESTWARD OVER THE TROPICAL

ATLANTIC AT ABOUT 15 MPH DURING THE NEXT SEVERAL DAYS.

ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR SOME DEVELOPMENT EAST

OF THE LESSER ANTILLES AROUND THE END OF THE WEEK. THIS SYSTEM HAS

A LOW CHANCE...NEAR 0 PERCENT...OF BECOMING A TROPICAL CYCLONE

DURING THE NEXT 48 HOURS...AND A MEDIUM CHANCE...30 PERCENT...OF

BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS.

Link to comment
Share on other sites

PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS

http://www.srh.noaa.gov/productview.php?pil=PMDMRD&max=61

Excerpt:

POTENTIAL TROPICAL ACTIVITY IN THE ATLANTIC ADDS ANOTHER LAYER OF UNCERTAINTY TO THE FORECAST FOR THIS PERIOD. THE CLIMATIC STATE IN THE ATLANTIC FAVORS ENHANCED TROPICAL CYCLONE ACTIVITY FOR THE NEXT ONE TO THREE WEEKS. BASED ON THE OFFICIAL HEIGHT BLEND, STORMS DEVELOPING IN THE MAIN DEVELOPMENT REGION OF THE ATLANTIC WOULD BE FAVORED TO RECURVE IN THE WESTERN ATLANTIC, ALTHOUGH THE EXTRATROPICAL/TROPICAL INTERACTION INVOLVED ALWAYS INCREASES UNCERTAINTY. TROPICAL DEVELOPMENT IS ALSO POSSIBLE JUST EAST OF THE LESSER ANTILLES; SUCH A SYSTEM IS FAVORED TO RECURVE, THOUGH IT IS TOO EARLY TO SAY WHAT THE IMPACT, IF ANY, MIGHT BE ON THE EASTERN CONUS.

Link to comment
Share on other sites

2001 had 8 hurricanes after the first cane didn't form until the 9th. Can't say I am that patient. These next few weeks are key to the season, before the MJO moves back into a less favorable phase. We better find a way get several hurricanes out of it or seasonal forecasts are in trouble.

Link to comment
Share on other sites

I. 10 Strongest MJO phase 1, 2 peaks during 8/21-9/20 since 1975: TC geneses when MJO 1.50+ in phase 1 or 2 that later became H’s

 

-3.08 peak 8/28/79: cat 5 David, cat. 4 Frederic, cat 2 Gloria

-2.21 peak 9/5/81: cat 1 Emily, cat 3 Floyd, cat 2 Gert

-2.07 peak 9/19/89: none

-2.01 peak 9/4/83: cat 1 Chantal

-2.01 peak 9/20/04: cat 1 Lisa

-1.98 peak 8/23/99: cat 2 Dennis

-1.92 peak 8/26/11: none

-1.90 peak 8/29/07: cat 5 Felix

-1.89 peak 8/30/88: cat 1 Debby

-1.88 peak 8/23/08: cat 4 Gustav

 

 

 

So, there were geneses of TC’s during these 10 strongest amplitude periods in phases 1 and 2 that later became 12 H’s (5 major) and these resulted in TC’s during  8 of the 10 periods that later became H’s.

Three hit the US as a H, two of them being major H hits.

 

 

 

II. 10 longest 1.50+ amplitude phase 1, 2 that peak 8/21-9/20 since 1975: TC geneses that later became H’s

 

-18 days 8/22-9/8/79: cat 5 David, cat. 4 Frederic, cat 2 Gloria

-11 days 8/29-9/8/81: cat 1 Emily, cat 3 Floyd, cat 2 Gert

-10 days 9/17-26/89: none

-9 days 9/2-10/83: cat 1 Chantal

-6 days 9/18-23/04: cat 1 Lisa

-6 days 8/28-9/2/07: cat 5 Felix

-5 days 8/27-31/88: cat 1 Debby

-5 days 9/12-16/04: cat 3 Jeanne, cat 4 Karl

-5 days 8/21-25/08: cat 4 Gustav

-4 days 8/22-25/99: cat 2 Dennis

 

 So, there were geneses of TC’s during these 10 longest periods in phases 1 and2 that later became 14 H’s (7 major) and these resulted in TC’s during  9 of the 10 periods that later became H’s. Four hit the US as a H, three of them being major H hits.

 

 

 

Conclusion:

 The upcoming phase 1 (and perhaps 2) MJO  is projected to be 2nd strongest (~2.40 per Euro) and tied for the 2nd longest at 1.50+ (8/28-9/7 or 11 days per Euro) of any phase 1 and 2 near the peak of the hurricane season since 1975. When considering strength and length, 1989 is the only analog that didn’t result in a genesis that later become a hurricane. However, it peaked at only 2.07 and that was on 9/19, which is a climatologically slightly less active period for genesis than the upcoming one. In addition, Hugo was already in existence and dominating the western Atlantic. Also, the 8/26/11 peak was 1.50+ for only 3 days long and peaked at only 1.92. In addition, H Irene was already in existence and was dominating the western Atlantic.  So, I’m predicting with high confidence (~95%) that there will at the very least one TC that forms (i.e., TD+) during 8/28-9/7/13 that later becomes a hurricane in the Atlantic basin.

Link to comment
Share on other sites

 Excellent post. Not only that but a whopping ~55% of years since 1950 in the neutral negative to weak La Nina range have had an actual US major H hit! That's excluding 1974 (per Josh, Carmen's US hit will be downgraded from major) and 2005 (very close call and could have been counted as neutral negative depending on classification methodology.) This is vs. the only ~30% for other years (moderate to strong La Nina, neutral positive, and El Nino). The very cool first half of August, if anything, raises that chance even higher per analogs. I'm maintaining my prediction that the US will be hit by a major H sometimes this season. In reality, I think the chance is a solid 2 in 3.

We'll see. For the next two weeks the USA seems to be pretty well protected, with a classic Omega Block across the country.

Link to comment
Share on other sites

We'll see. For the next two weeks the USA seems to be pretty well protected, with a classic Omega Block across the country.

 

Rose colored glasses, but even the deadest season can have a non-tropical system. 

Thinking of the last major to landfall in the HGX CWA, back in 1983.  So I'll watch the Florida blob, although I don't see any model support.  Not to mention the vorticity the Euro moves down from Mississippi tomorrow and offshore, even though I see nothing on satellite or radar, and the Euro shows no appreciable surface reflection.

 

Not every 12Z GEFS member misses ECUSA.  Sub 984 mb hurricane heading for NY in 2 weeks.

 

The heights on the Euro and Euro ensembles suggests a late developer could get through to Central America.

 

But yeah, even with my natural sunny optimism, the boring season is getting annoying.

Link to comment
Share on other sites

While many of us are focused on the wave in the Central Atlantic (and rightfully so given it has the highest probability of genesis in the next 5 days), the system over the Florida Straits does deserve some mention. While its clear most of the circulation is in the mid-upper levels, there is a surface reflection that is showing up on radar. Convection is starting to re-fire near the vortmax

 

2ij1awm.gif

Link to comment
Share on other sites

We'll see. For the next two weeks the USA seems to be pretty well protected, with a classic Omega Block across the country.

 

For cool Augusts and neutral negative to weak Nina ENSO, these were the 10 MH hit dates since 1950:

 

8/24, 8/26, 9/2, 9/5, 9/8, 9/20, 9/21, 10/3, 10/14, 10/17

 

 So, there are still five of these past the next two weeks. Of course, we don't know for sure that there won't be one even during the next two weeks.

Link to comment
Share on other sites

Yea the only way something makes it to North America given this pattern is if it stays week till it reaches the W Caribbean. The mid-level ridge simply isn't very strong over the Atlantic basin and unfortunately it looks more likely that the strong ridge over the midwest currently will just retrograde to the southwest in the long range. Thats why we have seen the ECWMF and GFS alternate between taking the system in the Caribbean (weaker solution) vs. north of the Lesser Antilles into the Atlantic (stronger solution). Anything TS strength or stronger will have enough of a mid-level reflection to cut through the feeble ridge.

 

If the wave is already trying to get its act together now, it might already be a goner. 

Link to comment
Share on other sites

I'm liking the homegrower down in the keys.. low shear, storm top divergence on radar is great. Marathon and the shoal stations are 15-20 kts from the NW though there are no buoys to the S.

Yeah that radar loop that Phil posted above certainly shows that in the last few hours it has come together some.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...