Forum:2019-20 South-West Indian Ocean cyclone season/Pre-season - December

96S.INVEST
Interesting. Tropical Tidbits is showing that there is a new invest in the SWIO. Not yet on JTWC's page though. Anonymous 2.0 (talk) 16:01, July 21, 2019 (UTC)
 * Gone from JTWC. Anonymous 2.0 (talk) 09:49, July 24, 2019 (UTC)
 * Actually, MFR did track this as Zone of Disturbed Weather 01. -- Java Hurricane  02:52, October 27, 2019 (UTC)

91S.INVEST
Up on Tropical Tidbits. Models take this into Madagascar as a C3/4. -- Java Hurricane  00:32, November 28, 2019 (UTC)
 * Code yellow on JTWC. Hopefully won't be bad for Madagascar if it hits, but I hope future Ambali would remain at sea, especially if it is expected to become a strong one. Would be a big season opener though if it becomes a Cat 3 or 4. Jas (Anonymous 2.0) (talk) 15:15, November 28, 2019 (UTC)
 * Also code orange, "moderate" chance according to TCWC Reunion. This could potentially be significant IMO. ~  Steve 🦃   Happy  Thanksgiving!  👪  17:23, November 28, 2019 (UTC)
 * No changes to the outlook since a few days ago. Still seems pretty likely to develop though, and might be "Ambali" by mid-week or so. ~  ☃ Steve ❄   Message Me  My Edits  📧  17:27, December 1, 2019 (UTC)
 * Now code orange on JTWC and code red on TCWC Reunion's outlook. ~  ☃ Steve ❄   Message Me  My Edits  📧  16:43, December 2, 2019 (UTC)

Zone of Disturbed Weather 02
Upgraded to a ZoDW per TCWC Reunion. Still code orange per JTWC. ~  ☃ Steve ❄   Message Me  My Edits  📧  16:55, December 3, 2019 (UTC)

Tropical Disturbance 02
Upgraded to a tropical disturbance and is now code red on JTWC, with a TCFA issued. Jas (Anonymous 2.0) (talk) 17:57, December 4, 2019 (UTC)
 * Currently 30 mph (25 knots)/1004 mbar per Reunion and expected to intensify to a 60 knot (70 mph) Severe Tropical Storm before hitting Madagascar. The race for Ambali is on between this and TD 03, the loser gets "Belna". ~  ☃ Steve ❄   Message Me  My Edits  📧  21:21, December 4, 2019 (UTC)

Tropical Depression 02
This is actually 02S, and is now upgraded to a tropical depression. Likely to become Belna later on and may strike Madagascar as a weakening system. Jas (Anonymous 2.0) (talk) 16:55, December 5, 2019 (UTC)

Now a JTWC TS. Forecast to reach 70 kt. -- Java Hurricane  00:47, December 5, 2019 (UTC)
 * Currently 35 mph (30 knots)/1000 mbar per TCWC Reunion and 45 mph (40 knots) per JTWC. I expect it to become Belna later today or tonight. ~  ☃ Steve ❄   Message Me  My Edits  📧  17:34, December 5, 2019 (UTC)

Moderate Tropical Storm Belna
Now a tropical storm, 65 mph (55 knots) per JTWC and 45 mph (40 knots)/998 mbar per Reunion. ~  ☃ Steve ❄   Message Me  My Edits  📧  00:26, December 6, 2019 (UTC)

Severe Tropical Storm Belna
Upgraded to a STS, 60 mph (50 knots)/992 mbar per MFR. ~  ☃ Steve ❄   Message Me  My Edits  📧  06:18, December 6, 2019 (UTC)
 * Nearing "Tropical Cyclone" intensity, 70 mph (60 knots)/985 mbar per MFR. Also 75 mph (65 knots) per JTWC. ~  ☃ Steve ❄   Message Me  My Edits  📧  17:25, December 6, 2019 (UTC)
 * Pressure down a bit to 982 mbar but still the same windspeed per MFR. ~  ☃ Steve ❄   Message Me  My Edits  📧  01:28, December 7, 2019 (UTC)

JTWC forecasts a 115 kt/130 mph cat 4 from Belna, but weakens it to a category 3 before making a landfall on western Madagascar southwest of Mahajanga. Ryan1000 13:35, December 7, 2019 (UTC)

Tropical Cyclone Belna
Now a TC, up to 90 mph (80 knots)/970 mbar per MFR and 115 mph (100 knots) per JTWC. Madagascar better be preparing for this potentially devastating storm. ~  ☃ Steve ❄   Message Me  My Edits  📧  06:28, December 8, 2019 (UTC)

It has apparently weakened a bit to 85 mph (75 knots)/970 mbar per MFR and 105 mph (90 knots) per JTWC. Still expected to intensify before landfall on Madagascar's western coast. ~  ☃ Steve ❄   Message Me  My Edits  📧  17:04, December 8, 2019 (UTC)

This went down to 75 mph (65 knots) yesterday per MFR, but is now back up to 80 mph (70 knots)/976 mbar. At least it didn't get too strong due to it threatening Madagascar and now it's about to make landfall. Per JTWC, it's currently 90 mph (80 knots). ~  ☃ Steve ❄   Message Me  My Edits  📧  16:59, December 9, 2019 (UTC)

Overland Depression Belna
Now an overland depression per MFR - currently only 30 mph (25 knots)/1004 mbar according to them and should die out completely within the next day. Hopefully it wasn't too bad. ~  ☃ Steve ❄   Message Me  My Edits  📧  16:51, December 10, 2019 (UTC)

Remnants of Belna
Final advisory issued by JTWC and MFR as it dies over Madagascar. ~  ☃ Steve ❄   Message Me  My Edits  📧  16:44, December 11, 2019 (UTC)

92S.INVEST
Another invest, this is to the east of the ZoDW. Currently code orange on TCWC Reunion's outlook. ~  ☃ Steve ❄   Message Me  My Edits  📧  16:55, December 3, 2019 (UTC)
 * Now code yellow per JTWC. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  01:00, December 4, 2019 (UTC)

Tropical Depression 03
Upgraded to a tropical depression by TCWC Reunion. Like 91S, this is also code red on JTWC now, another TCFA has been issued too. Jas (Anonymous 2.0) (talk) 17:57, December 4, 2019 (UTC)
 * If it continues intensifying at this pace, it looks more likely to be "Ambali". Currently 35 mph (30 knots)/999 mbar per Reunion and expected to quickly intensify to a Severe Tropical Storm before weakening as it poses no threat to land. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  21:24, December 4, 2019 (UTC)
 * Now a JTWC storm. -- Java Hurricane  00:46, December 5, 2019 (UTC)

Severe Tropical Storm Ambali
And this one became Ambali. Now an STS and already a C1 on the SSHWS. Currently 60 mph (95 kph)/990 mbars. By the way, this is actually 03S, not 02S. Jas (Anonymous 2.0) (talk) 16:54, December 5, 2019 (UTC)
 * Wow this is intensifying quickly. Now 60 mph (50 knots)/990 mbar per Reunion and 80 mph (70 knots) per JTWC. The latter expects this to become a 115 mph (100 knot) beast very soon before weakening begins. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  17:37, December 5, 2019 (UTC)

Intense Tropical Cyclone Ambali
This is BOMBING OUT! A well-defined eye is now visible and it's now 115 mph (100 knots) per JTWC and 105 mph (90 knots)/962 mbar per Reunion. JTWC now forecasts a powerful 150 mph (130 knot) beast. I can't believe how quickly this has been intensifying... 😮 ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  00:23, December 6, 2019 (UTC)

Very Intense Tropical Cyclone Ambali
Soon after I wrote that, it has intensified even more. Now a VITC, the first since Fantala in 2016, with winds of 140 mph (120 knots) and a pressure of 930 mbar according to TCWC Reunion. Even the record-active year last year couldn't produce a storm as powerful as this. I have no words anymore... 😮 ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  01:13, December 6, 2019 (UTC)
 * Now 155 mph (135 knots) per JTWC. Hopefully this will be Ambali's peak intensity. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  06:16, December 6, 2019 (UTC)

Apparently so, and thankfully it's well away from land at this intensity, though it might eventually end up in Mauritius or Reunion as a tropical storm. Also, according to the JTWC, Ambali's winds increased a whopping 115 mph in 24 hours, which is the fastest intensification by windspeed in a 24 hour time period in the southern hemisphere since 1980. For comparison, the almighty Patricia in the EPac had a 120 mph increase in that same time period from October 22-23 in 2015. Ryan1000 07:28, December 6, 2019 (UTC)
 * The JTWC botched the intensity up. It was a Category 5 at 0Z, but they held their estimate at 135 kt. -- Java Hurricane  07:29, December 6, 2019 (UTC)

Tropical Cyclone Ambali
It's now weakening quite rapidly as well. Down to 90 mph (80 knots)/968 mbar per MFR and 105 mph (90 knots) per JTWC. It was fun while it lasted though. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  17:23, December 6, 2019 (UTC)

Severe Tropical Storm Ambali (2nd time)
Back down to STS intensity according to MFR - 70 mph (60 knots)/980 mbar. Expected to die out by Monday. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  01:25, December 7, 2019 (UTC)

Remnants of Ambali
Died out over the open sea. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  06:26, December 8, 2019 (UTC)

AOI: Northeast of Mauritius
Up on MFR's outlook with code yellow. No invest designation yet. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  16:47, December 11, 2019 (UTC)

96S.INVEST
Invested. Maybe Calvinia could come from this. ~ <font face="Verdana"> ☃ Steve ❄   Message Me  My Edits  📧  19:20, December 12, 2019 (UTC)

Now code yellow on JTWC, although MFR has dropped it from their outlook. Honestly I doubt much will come out of this. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  18:18, December 16, 2019 (UTC)
 * Now code red, TCFA issued. Will Calvinia come out of this one? I hope so, especially now that it looks organized in the most recent JTWC satellite images. Jas (Anonymous 2.0) (talk) 04:45, December 19, 2019 (UTC)
 * MFR is being strange. They don't even have the system on their outlook. -- Java Hurricane  13:58, December 19, 2019 (UTC)
 * Back down to code yellow (TCFA cancelled). I've lost hope for this becoming Calvinia. I've also noticed the MFR's lack of mention in the past couple days, although their latest daily outlook (the first since the 16th) gives this a "low" chance for just the next 36 hours. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  18:47, December 19, 2019 (UTC)

When I thought 96S was moving into the Mozambique Channel, I believed this was a separate system but it appears that wasn't the case.

MFR is monitoring another area for development for the weekend, this is code yellow (low chance) on their outlook. This seems unrelated to 96S which is expected to move over Madagascar and develop in the channel. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  21:11, December 23, 2019 (UTC)

Now code orange per MFR. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  17:00, December 25, 2019 (UTC)

Up to code red on MFR, still code yellow on JTWC. However, JTWC hints at possible development due to favorable conditions. After a couple weeks of lingering, I guess it might finally decide to develop? ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  20:15, December 26, 2019 (UTC)

Now code orange per JTWC. Might be declared a Zone of Disturbed Weather anytime in the next day or two. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  05:52, December 27, 2019 (UTC)

Code red per JTWC, TCFA issued. I expect a tropical cyclone to form over the weekend. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  20:47, December 27, 2019 (UTC)

Zone of Disturbed Weather 04
Declared a ZoDW last night at 0600 UTC... ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  22:49, December 28, 2019 (UTC)

Tropical Disturbance 04
...and became a Tropical Disturbance very soon afterwards, the third of the year to reach this classification. Current intensity per MFR is 25 knots (30 mph)/1001 mbar and it is expected to intensify to a 45 knot (50 mph) Moderate TS. I won't rule out a brief Severe TS though out of to-be Calvinia. Still code red per JTWC but they should initiate advisories pretty soon. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  22:49, December 28, 2019 (UTC)

Tropical Depression 04
Upped to a tropical depression yesterday evening (PST time)... ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  21:13, December 29, 2019 (UTC)

Moderate Tropical Storm Calvinia
...and was upgraded to a named storm this morning, currently 35 knots (40 mph) according to MFR and JTWC and 992 mbar. MFR still expects it to peak at 45 knot (50 mph) while JTWC forecasts a 50 knot (60 mph) peak as it moves south after passing near and affecting the Mascarenes Islands. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  21:13, December 29, 2019 (UTC)

Severe Tropical Storm Calvinia
Upped to a STS per MFR, currently 55 knots (65 mph)/980 mbar according to them. Now expected to intensify to "Tropical Cyclone" status. According to the JTWC, it's 50 knots (60 mph). Looks like this exceeded the initial intensity forecasts. It's also been moving very slowly and stalling near Mauritius, causing torrential rainfall and flooding on the island. ~ <font face="Verdana"> Steve   Goodbye  2019!  ⚰️  02:15, December 31, 2019 (UTC)

Tropical Cyclone Calvinia
Now at "TC" intensity and officially a year-crossing storm, and even better, a decade-crossing storm (if you count the decade as 2010-19, not 2011-20 due to no year zero). According to MFR, it's currently 65 knots (75 mph)/973 mbar. JTWC has it at 70 knots (80 mph). It has peaked and is now expected to weaken from here on out as it moves quickly southeast away from Mauritius. ~ <font face="Verdana"> Steve   Goodbye  2019!  ⚰️  06:59, January 1, 2020 (UTC)

Post-Tropical Depression Calvinia
You have been very lonely on this forum page, Steve! (P.S. I left you a comment on your latest blog post. I hope you consider some of my suggestions.) Regarding Calvinia, RSMC La Réunion has declared the system post-tropical. Their latest bulletin stated Calvinia's ten-minute winds are at 60 knots (70 mph), with a pressure of 976 mbar (hPa). Because of heavy wind shear and dry air, Calvinia should dissipate within the next couple of days. Although year-crossing storms are not that uncommon in the Southern Hemisphere, it is not every day a tropical cyclone exists in two decades! Andrew Talk To Me  Contribs  Mail Me  00:12, January 2, 2020 (UTC)
 * Yeah, nobody else seems to care about the southern hemisphere... I'm a bit surprised Calvinia degenerated so quickly after its peak. A storm crossing two decades is really an amazing feat. But what was even more amazing was Severe Tropical Storm Astride back in 1999-2000, which crossed two millennia! (One can also consider Intense Tropical Cyclone Ando a year later as being the true millennia-crosser) ~ <font face="Verdana"> Steve 🎉   Happy  2020!  🎆  01:21, January 2, 2020 (UTC)


 * RSMC La Réunion has issued their final advisory on Post-Tropical Depression Calvinia. It may already be extratropical. Andrew  Talk To Me  Contribs  Mail Me  18:06, January 2, 2020 (UTC)

AOI: Mozambique Channel
Archived posts from when I thought this was 96S (the real invest is above)

The invest is still lingering... still code yellow for both agencies, although MFR's area of interest is now over northern Madagascar. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  04:10, December 22, 2019 (UTC)

The area of interest has shifted to the northern Mozambique Channel. I guess after all these days of lingering, the invest might finally decide to develop there. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  21:10, December 22, 2019 (UTC)

Now code orange (moderate chance) per MFR for development in the northern Mozambique Channel. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  21:11, December 23, 2019 (UTC)

Down to code yellow per MFR, but might still have a chance to briefly develop in the Mozambique Channel. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  17:00, December 25, 2019 (UTC)

No longer on the outlook. Because JTWC is still monitoring 96S with code yellow east of Madagascar, I guess 96S stayed east the whole time and this was a separate system. ~ <font face="Verdana"> Steve 🎄   Happy  Holidays!  🎅🕯  20:15, December 26, 2019 (UTC)