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Super Typhoon Rammasun Makes Landfall – Next Up Tropical Storm Matmo

By: Dr. Jeff Masters, 5:49 PM GMT on July 18, 2014

(By Steve Gregory - Substituting for Dr. Masters who is on Vacation.)



Figure 1: NEXSAT image showing both Rammasun and newly formed T.S. Matmo just a couple hours before Rammasun made landfall.

Super Typhoon Rammasun has made landfall on the Luichow Peninsula just north of Hainan most likely as a low end CAT 4 Typhoon. (Officially, JTWC has carried it as a borderline CAT 5). Haikou on the north coast of Hainan, about 50NM SSE of the storm center, reported a sustained wind of 68Kts with gusts to 88Kts (100mph) as the storm passed just to their north, and a minimum pressure of 955mb. Winds continue to gust to tropical storm strength as of the writing of this report.

Rammasun intensified rapidly during the past 12-18 hrs as a strong outflow channel developed equatorward of the storm, and wind shear decreased to about 15kts. With an east-west ridge line just north of the storm, Rammasun should develop a more westward track during the next few hours and is expected to make its final landfall in northern Vietnam by around 03Z Saturday.



Figure 2: One final WV image clearly showing Rammasun’s eye and very large circulation field.

UP NEXT: MATMO

Since yesterday, TD 10W has become slightly better organized and is now being carried as Tropical Storm Matmo. The slowly developing cyclone is about 235 NM north of Koror, Palau, and is drifting WNW at about 3-5 kts. Dvorak estimates and imagery loops suggest Matmo remains a borderline storm, but the marginally conducive environment is expected to become more favorable for intensification during the next 72 hours as the storm begins to track northwestward at a somewhat faster forward motion.

All of the specialized hurricane forecast models are in generally good agreement that Matmo will intensify to CAT 2 as it approaches Taiwan by the middle of next week. A couple models are calling for a much stronger storm – though these appear to be outliers at this point (as are some of the Japanese models that show a more northerly track towards Japan). It is worth noting that after 6 model runs forecasting only minor development, the GFS has come back into excellent agreement with the Hurricane models in forecasting a vigorous cyclone, tracking it towards northern Taiwan.



Figure 3: The above product depicts satellite derived winds, with strong outflow channels to the south of Rammasun. However, only a weak outflow exists to the northwest of MATMO, and poor outflow in all other quadrants around the cyclone..



Figure 4: The 06Z HWRF model run shows a somewhat more eastward track projection for Matmo compared to the GFS, but other models (not shown) show a track closer to that of the GFS.



Figure 5: Interpreting the Intensity forecast models is somewhat more problematic – with the typically more reliable models calling for Matmo to eventually become a CAT 1 or CAT 2, but a couple models are calling for a far more intense storm. Considering the EURO and GFS global model solutions, I tend to believe a low end CAT 2 to be the most likely outcome.



Figure 6: The official JTWC forecast calls for Matmo to be a CAT 2 Typhoon as it approaches northern Taiwan on Wednesday.

TROPICAL STORM WALI

An unusual (but certainly not rare) Tropical Depression formed yesterday in the central Pacific, about 1,100 NM ESE of the Hawaiian Islands. By early today, better organization of the small cyclone prompted NOAA forecasters to officially designate the system Tropical Storm ‘Wali with 40Mph winds. The storm is currently located about 950 NM ESE of Hilo.

The storm is moving slowly W-NW, and while it may intensify a bit more, cooler SST’s and most notably, stronger wind shear and drier air should significantly weaken the system prior to it reaching the Big Island on Tuesday.



Figure 7: Enhanced IR imagery of Tropical Storm WALI. It’s relatively deep convection and symmetrical signature prompted NOAA forecasters to upgrade the storm early today, but the storm remains quite small and is heading towards a more hostile environment.



Figure 8: Wali is currently located in a relatively low wind shear environment, but a deep TROF NW of the Hawaiian Islands is generating strong, southwesterly wind shear over the eastern Islands and will impact Wali as it heads towards the Big Island in a couple days.



Figure 9: Official Track forecast for Wali

TROPICAL ATLANTIC

The Tropical Atlantic remains fairly quiet – but continues to trend towards a more seasonal pattern as wind shear continues to ease off, and more distinctly, the environment has continued to 'moisten' up.

The Tropical Wave that first emerged off the African coast early yesterday has moved westward, loosing most of its deep convection. However, the wave has brought a strong moisture surge to the eastern Atlantic, though the warm Saharan air has stifled convection.

The more significant wave approaching the Windward Islands and is bringing showers and some heavier convection to the Islands, which will continue westward over the weekend. While wind shear as fallen off considerably compared to last week, it remains relatively high across the southern CARIB, especially in the SW CARIB, and this fact alone will prevent the Tropical wave near the Windward Islands from developing.

While none of the global models are forecasting any cyclone development during the next 10-14 days, the environment is expected to become a bit more conducive to cyclone formation during the last week of the month.



Figure 10: Todays 'big picture' shows the wave bringing significant rainfall to the Windward Islands, with the eastern Atlantic wave representing the leading edge of a significant moisture surge. (While not clearly shown, another large wave over west Africa should reach the coast by tomorrow.



Figure 11: The above enhanced water vapor image highlights the moisture surge over the eastern Atlantic that has accompanied the large tropical wave that came off the coast early yesterday.



Figure 12: The wide view water vapor imagery shows the continuing ‘moistening’ across the Tropical Atlantic Basin – a dramatic change compared to the first 10 days of July.



Figure 13: Wind shear continues to decline across the basin, but remains relatively strong across the southern CARIB which will inhibit any development of the wave near the Windward islands.

Next update will be Saturday afternoon.

Steve Gregory

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

NHC is doing the normal process, no surprise here. Not all of the requirements met just yet.
Quoting Gearsts:
Maybe if we post more pics of the wave and the gfs run, it will develop.


RI for sure if we do that.
Quoting 502. Sfloridacat5:



RI for sure if we do that.

Quoting 499. Climate175:

Go look at Far East Africa.
Quoting 496. beell:



If it was me, (which it ain't) I'd wait until it clears the western end of the monsooon trough (40-45W?) and see how much low level curvature it can retain.
Or moisture, even. It did bring a big surge of moist air with it, but the air across that part of the MDR is still pretty darned dry.... I'm still giving equal chances at best.
Quoting Gearsts:



It's worth a try. At least there's something to watch on our side of the world.
Partly Cloudy

89°F

32°C

Humidity70%
Wind SpeedE 7 mph
Barometer30.07 in (1018.3 mb)
Dewpoint78°F (26°C)
Visibility10.00 mi
Heat Index103°F (39°C)

Last Update on 19 Jul 12:53 pm EDT

Current conditions at

St. Petersburg / Clea (KPIE)

Lat: 27.91°N Lon: 82.69°W Elev: 10ft.

More Local Wx | 3 Day History | Mobile Weather

It's nasty here today.
Quoting 504. redwagon:

Quoting 499. Climate175:

Go look at Far East Africa.
That will be the next area to watch.
Avila.
Quoting 418. HurricaneHunterJoe:

The " storm " is still sprinkling upon me here in Soo Cal!




Not made it down to the lower coast so far. Just overcast in San Diego.
I think a small undetected T.D. went over my house. The winds came from the N.E. then it got calm(the eye). Then the winds came from S.W. This all happened in a 10 minute time frame. No damage ,so I'm happy 'bout that!LOL
Just had a very intense thunderstorm here, lasted about 30 mins , torrential rain and lots of thunder and lightning.

UK rain radar
514. JRRP
Quoting Gearsts:
Maybe if we post more pics of the wave and the gfs run, it will develop.

jajajajajaja
Quoting 426. HurricaneHunterJoe:



I am starting to forget what it looks like! But, the street is almost wet!


I agree. We should get more than spitting in the street. Nothing here yet, but the skies look darker than usual.
the eastern atlantic for the last couple of seasons has really appeared dead. really miss the CV storms that would develop...
Quoting 501. Climate175:

NHC is doing the normal process, no surprise here. Not all of the requirements met just yet.
Speaking of which, anybody remember which website it was that had the checklist of requirements for cyclogenesis on it?

[aka I Have Too Many Links] .... lol...
Quoting 510. Sfloridacat5:



If nothing else this big guy (if he makes the splash) will plow through that SAL, clearing a path.
Quoting 510. Sfloridacat5:


Notice also the system over UK / W Europe, and the dry air NW of the Caspian Sea...

Quoting 513. ZacWeatherKidUK:

Just had a very intense thunderstorm here, lasted about 30 mins , torrential rain and lots of thunder and lightning.

UK rain radar
Currently just overcast and sullen here. At least it's not as hot as it was yesterday p.m. - so far.
There is anything at 2 PM TWD about wave that open eyes.

A TROPICAL WAVE EXTENDING FROM 16N29W THROUGH A 1014 MB LOW NEAR
09N31W TO 07N31W IS MOVING W 10-15 KT. SCATTERED SHOWERS AND
TSTMS ARE IN THE VICINITY OF THE LOW WITH NO CONVECTION
ELSEWHERE.
521. flsky
Off topic - but this should make you feel great!
Link

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT JUL 19 2014

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE EXTENDING FROM 16N29W THROUGH A 1014 MB LOW NEAR
09N31W TO 07N31W IS MOVING W 10-15 KT. SCATTERED SHOWERS AND
TSTMS ARE IN THE VICINITY OF THE LOW WITH NO CONVECTION
ELSEWHERE.
Quoting 480. Grothar:

Matmo


Matmo is growing feathers, which means he is filling his lungs.
527. Mikla
Quoting 517. BahaHurican:

Speaking of which, anybody remember which website it was that had the checklist of requirements for cyclogenesis on it?

[aka I Have Too Many Links] .... lol...

This?
JeffMasters has created a new entry.
IVAN
09/04/2004 12 GMT 8.9 36.5 60 997 Tropical Storm

It is possible to get a TS that far south, though IIRC Ivan is the recordholder in that regard. Consider that not only was Ivan a more vigorous system than this current Twave from the get-go, but also that Ivan formed at the apogee of the season, when conditions are traditionally at their most propitious.

So, could this Twave become "another Ivan"? Well, it's not impossible, but the likelihood is pretty low. I find it's better in these situations to be realistic / pragmatic. That way if the unexpected happens, well, one can enjoy a genuine surprise. :o)

Realistically, [and hopefully] we can expect this Twave to give us at best a TD / weak TS going into the Lesser Antilles, hopefully retaining enough of its moisture to provide some drought relief in the area. And development even to invest status is unlikely to occur before it crosses 40W, and probably closer to 50W....

Let's see what happens.....

Quoting HurricaneHunterJoe:
Pottery...........It looks like the winds chewed up that nice wave that went over you yesterday. And looks like another coming through today. Glad they holding together til they get to you.

True that !

Should start getting some heavy showers again tonight.
I can live with that, for sure !
Quoting JRRP:

jajajajajaja
fingers cross
Good Luck to those folks in Washington state and Canada who are fleeing that awful fire over there...hope you get out safely.
Will be watching this with interest as it's getting that time of year for the Cape Verde season to kick off. Although the cooler than average SST's in that part of the world will hinder development I'd assume. All the warm waters are from the Windward islands westward. So I would tend to think that the models may have a hard time with this but I do expect to see some rapid intensifiers this year when they get into those really warm SST's between the U.S. and Windward Island. Some high ACE levels building too. Given the placement of the Subtropical high over the Atlantic will be interesting to see how the storms recurve. One may think they would steer right into the Eastern Seaboard. That said some powerful mid latitude troughs are dropping down and traversing the country and the steer them away. Going to be interesting to watch when things start to really fire up.