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sausiuswx.bsky.social @sausiuswx.bsky.social · 1h

Pressure has dropped bigly since last recon mission (almost 8 mbar). Now into the low 930s. Recon finding FL winds of 129 kts in the eatern Eyewall. Still suggesting winds of at least 115 kts but stronger winds are surely to be found elsewhere in the storm (like on the NE).

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sausiuswx.bsky.social @sausiuswx.bsky.social · 3h

The satellite presentation of Melissa is just inmpecable. Gravity waves eminating through the very symmetrical cold CDO surrounding the small highly circular 20°C eye. Very very nice banding on the eastern semicircle as well. Definetely sat presentation of a high-end hurricane.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 4h

The satellite presentation has also improved if anything since the last advisory. Of course none of the wind data suggested intensities up to 130 kts but always remember that those are always representing the floor of what is present within the storm, due to undersampling.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 4h

Interestingly the objective and subjective dvorak estimates all suggest that Melissa is a category 5. AiDT and D-PRINT also agree. Therefor NHC may go with 125-130 kts at the next advisory, esp. considering that the pressure has decreased again throughout the last mission. (1/2)

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sausiuswx.bsky.social @sausiuswx.bsky.social · 5h

The eye is now warmer (>18°C) and contracting slightly. The CDO also remains very cold and symmetrical, contracting ever so slightly as well. Neat banding continues on the eastern side. Under the hood merger EWRC may be occuring. Melissa continues on course for Cat5 intensity.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 5h

The pressure has started dropping again and is now in the low 940s but there is still no evidence from the wind side that the winds have increased beyond 120 kts. It does look however look like Melissa is done taking a break and is now strengthening once more.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 7h

Latest recon data further confirms the notion that the intensity of Melissa has levelled off for the time being. In fact NHC estimate remains slightly bullish compared to aircraft data. Wind measurements more in line with 110-115 kts. Pressure compatible with 115-120 kts.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 8h

For Folks in Jamaica, your time is up! It is now time to hunker down and hope for the best. Torrential rain capable of causing catastrophic and life-threatening flash flooding and numerous landslides begins today, followed by potentially devestatig winds beginning Monday night.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 8h

NHC doesn't however seem to see any direct evidence for imminent eyewall replacement and such evidence is certainly not known to me either. W Shear could actually work against this, in preventing concentric bands from fully wrapping around the core and enclosing the inner eyewall

sausiuswx.bsky.social @sausiuswx.bsky.social · 8h

The intensity of Melissa has seemingly levelled off today, according to recon data from this morning (tho a new mission is investigating rn). The effects of some W shear are still evident. NHC also reporting occasional breaks in the eyewall and some concentric banding.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 12h

The waters of the central carribean are like rocket fuel for tropical cyclones and have catapulted Melissa from a high end tropical storm to a category 4 monster. A stunning metamorphosis. Seems like only internal processes could slow her down. Jamaica is in big, huge trouble.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 1d

The satellite presentation of Melissa is now evolving very rapidly indeed. Needless to say that Melissa now has her foot firmly on the loud pedal and is in the midst of an impressive period of rapid infensification that will see her become a major hurricane in no time at all.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 1d

Tail mounted doppler radar data for Melissa supports a fairly symmetrical windfield actually and aligns very well with the NHC fix of 85 kts (92.5*0.9= 83,25). Data also shows the solid, closed eyewall. Structure poised for further rapid intensification for sure.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 1d

Preliminary recon data suggests that Melissa may already a category 2 on the SSHWS. At the very least she is on the cusp. The 97 kts FL winds come out to about 85-90 kts at the surface (87.3 to be precise). The XTRAP MSLP of 970.8 would also support that.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 1d

To expand on this, on thursday I already said that NHC key messages hardly come more strongly worded. Well, they have upped the anti even further. It is important to stress that NHC does not choose their words lightly. THIS IS A LIFE THREATENING SITUATION FOR JAMAICA & SW HAITI!

1. Jamaica: A multi-day period of damaging winds and heavy
rainfall is expected to begin tonight, causing catastrophic and
life-threatening flash flooding and numerous landslides. Extensive
infrastructural damage, long-duration power and communication
outages, and potentially prolonged isolation of communities is
likely. A life-threatening storm surge is also likely along
portions of the southern coast early next week. All preparations
should be completed today.

2. Haiti: Catastrophic and life-threatening flash flooding and
landslides are expected across southwestern Haiti into early next
week, likely causing extensive infrastructural damage and
potentially prolonged isolation of communities. Strong winds could
also potentially last for a day or more over the Tiburon peninsula.

3. Dominican Republic: Heavy rainfall could produce catastrophic
flash flooding and numerous landslides in southern portions of the
country.

4. Eastern Cuba, Southeast Bahamas, and the Turks and Caicos:
Monitor Melissa closely. There is an increasing risk of a
significant storm surge, damaging winds, and heavy rainfall by the
middle of next week. In eastern Cuba, the risk of life-threatening
flash flooding and landslides is increasing. A Hurricane Watch is
now in effect for portions of eastern Cuba.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 1d

The newest rainfall forecast for Melissa is just horrific frankly. WPC now forecast more then 30 in of rain in parts of E Jamaica over the next 4 days. Possibly up to 40 in, that would be 1000 l/m2 (mm)! Just wow! The results of this in Jamaica and SW Haiti won't be pretty at all

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sausiuswx.bsky.social @sausiuswx.bsky.social · 1d

Melissa has now finally been made a hurricane by the NHC. Rapid intensification into a high-end tropical cyclone and a catastrophic near cat5 landfall in Jamaica are expected. The threat of life-threatening flooding will already precede this over the weekend there and in SW Haiti

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sausiuswx.bsky.social @sausiuswx.bsky.social · 1d

Looks like Melissa is ready to hit the loud pedal. Satellite presentation has improved markedly since yesterday. Hurricane Hunters reporting measurements supporting (near) hurricane strength and an (almost) closed eyewall. Mw images from this morning already showed that nascent core.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 2d

Hurricane hunters have found the pressure of Melissa to have been at least 4-5 mbar lower then at the end of their last mission 6 hours ago. 993.7 dropsonde vs. 997. The center continues to be on the western side of the cloud mass tho. So far no stronger winds then last misison.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 2d

"...LIFE-THREATENING AND CATASTROPHIC FLASH FLOODING AND LANDSLIDES
EXPECTED IN PORTIONS OF SOUTHERN HISPANIOLA AND JAMAICA THROUGH THE
WEEKEND..."
NHC advisories hardly come more strongly worded then this and they do not choose their words lightly. Extremely serious situation!

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sausiuswx.bsky.social @sausiuswx.bsky.social · 2d

It is important to remind folks in Jamaica that rapid if not extremely rapid intensification is expected. The NHC has made one of their most bullish forecasts in history, calling for a hurricane in 12, major in 36 and near Cat5 in 60 hours. Things gonna escalate extremely fast.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 2d

The forecast scenarior for Melissa remains complex. Rn tho the most likely scenario appears to be a direct hit or landfall for Jamaica and then E Cuba as an extremely dangerous major hurricane. Torrential rain capable of causing life-threatening flooding is expected in Jamaica & SW Haiti.

sausiuswx.bsky.social @sausiuswx.bsky.social · 2d

There has been some improvement in the satellite presentation lately, with convection curling towards the low-level circulation center. This supports a decrease in shear suggested by guidance. Shear still is unfavourable tho and as a result Melissa remains vertically tilted.

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sausiuswx.bsky.social @sausiuswx.bsky.social · 3d

I would imagine that a major cause for the downtrend is increased land interaction. Tho in both cases I cannot access many of the individual members to confirm this. Another reason is that a more northerly track seems to expose Melissa to slightly higher shear.

sausiuswx.bsky.social @sausiuswx.bsky.social · 3d

We are lately seen a bit of a downtrend in the modelling. You can see that in both the IVCN and the HCCA cosnensus aid. Consensus aids also show the general north(east)ward trend in the guidance. Flooding remains a huge concern either way. Graphics courtesy of Brian Tang.

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