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"Lots of torrential showers coming tonight."
After looking at what appears to be upstream of us in the satellite imagery this morning, I am making a few preperations for the possibility of heavy duty torrential rains over the next couple of days.
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"What's your point, terracore?"
I'll try a bigger font this time so that you can see it:
Most of the spaghetti models show the storm veering south of the island very similar to the SHIPS NWS model. All of the models now predict slightly higher winds to reflect the actual wind speeds of 55 knots at 1100 HST.
Intensity / Wind Speed Projections for NIALA
06 CP spaghetti models
Highest predicted winds
Median: 55.0 knots
Average: 55.25 knots
Highest predicted winds of all models
OCD5: 57 knots
SHF5: 57 knots
SHFR: 56 knots
LBAR: 55 knots
OFCI: 55 knots
SHIP: 55 knots
NGXI: 55 knots
NAMI: 55 knots
MRCL: 55 knots
LGEM: 55 knots
OFCL: 55 knots
IVCN: 55 knots
ICON: 55 knots
HWFI: 55 knots
GHMI: 55 knots
GFTI: 55 knots
GFDI: 55 knots
DSHP: 55 knots
DRCL: 55 knots
AVNI: 55 knots
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Thanks Terracore for the no glasses needed post
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eTRap is a great way to measure tropical rainfall potential;
http://www.ssd.noaa.gov/PS/TROP/etrap.html?storm=NIALA
Used to really rely on TRMM but it was turned off and burned up over the Indian Ocean on June 15th 2015;
GPM has helped some and I can hardly wait until GOES-R is launched next year.
http://pmm.nasa.gov/TRMM/realtime-3hr-7day-rainfall
Lucky for us the subtropical jet is very strong and lies right over the state;
http://www.stormsurfing.com/cgi/display_...a=npac_250
Ideally you don't want to be on the North side of a tropical cyclone and that's where it looks like we'll be tomorrow. There is still a spot of intense uplift occurring. We could be subject to an intense convective cell. With the high level shear from the subtropical jet so strong, it looks like sometime soon Niala's top will be sheared off. It looks like only the low level center will be able to move West against the strong jet. We could still get alot of rain especially if the freezing level continues to lower-it was 17k 2 days ago now it's 14.6k; Rains can be incessant when the freezing level is low!
http://forecast.weather.gov/product.php?site=NWS&product=FZL&issuedby=ITO&format=TXT&version=1&glossary=0
First 2 numbers are relative humidity and the last 3 are elevation in 100s of feet.
Another place to monitor stroms is here, Just click on your storm of interest and they have great info about intensity and guidance;
http://www.ral.ucar.edu/hurricanes/realtime/current/
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Excellent - mahalos again, Ino. Bracing for a possible deluge of pocket bible -ish proportions.
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Thank you once again, Ino. Just a quick question as you raised something I wasn't aware of:
"Rains can be incessant when the freezing level is low!"
Could you explain why that's the case? I can think of one or two possibilities, but not an expert. My immediate thought is when freezing levels are low in a warm tropical area, then the large temperature gradient plays a part, but don't really know. Thanks.
PS. Quick afterthought. Perhaps all the potential energy held by the ice particles at much lower altitudes than normal plays a big part as well. It wouldn't require much to release all that energy.
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"Rains can be incessant when the freezing level is low!"
"Could you explain why that's the case? I can think of one or two possibilities, but not an expert. My immediate thought is when freezing levels are low in a warm tropical area, then the large temperature gradient plays a part, but don't really know. Thanks."
I'm oversimplifying here and it's weather so there are always exceptions but generally an answer to your question is that when low freezing levels are present in a warm tropical area this allows the clouds to grow much taller, getting into that cold air to condense and release their latent heat to start that feedback loop is much easier than when the cold air is higher or access is blocked. This allows raindrops to achieve a much larger size that is not possible if they can't reach that cold layer.
When strong capping inversions are in place the raindrop's size are limited and convection is suppressed. Under inversions the raindrop's size often are just misty or very small drops at the most. In fact for raindrops to get big they need access to gather together in the cold air. When it really pours and the raindrops are big, they are coming from above the freezing level here.
An interesting local effect is observed here quite frequently starting about now and lasting thru Spring. Cold parcels of air in the upper atmosphere move South here to the Central Pacific Cold Front graveyard where they quite commonly leave pockets of cold air aloft on our local mountains. The mountains seem to protect these cold air parcels from modification from the warm Sea Surface Temperatures, not forever but for what can seem like forever. Kinda of like a giant ice cube sitting on a steaming warm air mass = copious rainfall amounts.
When this happens, "We wonder when will the rain end? Usually only when the FL goes back up or the inversions return or the air mass modifies.
We will see some of this tomorrow as we have cold air in place above us and it is much lower than what the season would normally allow, then we have a warm core cyclone moving underneath it. This is what the shear is all about. Cold air aloft moving East with warm surface air moving West. Without this shear we would be facing a much stronger storm. You can see who's winning - the subtropical jet is,it is literally stripping away the warm air. We'll get lots of rain with big drops and this fits the definition of unstable weather.
To sum up the lower the FL (Freezing Level) the colder the air on the top is making the atmosphere more unstable (cold air on top of warm air) and there seems to be an never ending plume of warm moist air available here for uplift to begin mixing it up with all that cold air.
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Thank you, Ino. Suspected latent heat would come into this. Lots of energy that has to go somewhere.
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WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...
THE TROPICAL STORM WATCH FOR THE BIG ISLAND HAS BEEN DISCONTINUED.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
NONE.
INTERESTS IN THE MAIN HAWAIIAN ISLANDS SHOULD CONTINUE TO MONITOR
THE PROGRESS OF TROPICAL STORM NIALA THIS WEEK.
