Dangerous Caribbean disturbance 95L close to tropical storm strength
A tropical wave (Invest 95L), moving westward at 15 mph though the south-central Caribbean, will bring gusty winds and heavy rain squalls to the northern coasts of Colombia and Venezuela this morning, as well as the Netherlands Antilles Islands. This disturbance will bring dangerous flooding rains to the countries bordering the Western Caribbean this weekend, and may also be a threat to the U.S. Gulf of Mexico coast late next week. A hurricane hunter aircraft is in 95L, and found a large region of surface winds of 35 - 45 mph to the east of 95L's center. If they find a closed circulation, 95L will be upgraded to Tropical Storm Matthew today. Satellite loops show that heavy thunderstorm activity has increased markedly in recent hours, with a solid curved band of intense thunderstorms growing to the northeast of 95L's center. Low-level spiral bands are also developing to the southeast of the center, but a closed surface circulation is not yet obvious from satellite imagery.
Figure 1. Morning satellite image of 95L.
Forecast for 95L
An upper-level high pressure system lies to the west of 95L, near the coast of Nicaragua. The clockwise flow of air around this high will bring a moderate 10 - 15 knots of wind shear over 95L today. By Friday, 95L will move more underneath this upper-level high, causing the shear to decline. The SHIPS model forecasts that shear will fall to the low range, 5 - 10 knots, by Friday afternoon. This drop in shear may allow for rapid intensification of 95L as it approaches landfall near the Nicaragua/Honduras border on Friday night and early Saturday morning. NHC is giving the disturbance an 80% chance of developing into a tropical depression by Saturday.
Figure 2. Forecast track of 95L from an ensemble of runs of the GFS model done at 2am EDT this morning.
The future of 95L depends critically upon the storm's interaction with land over the coming days. If 95L misses making landfall in Nicaragua and Honduras, and instead skirts the north coast of Honduras, the storm is likely to intensify into a hurricane by Monday, as predicted by last night's 00Z (8pm EDT) run of the GFDL model. However, if 95L spends significant time over Honduras, as predicted by the latest 06Z (2am EDT) run of the GFDL model, the storm will likely stay below hurricane strength. 95L is being forced just north of due west by a strong ridge of high pressure. This ridge will keep the storm moving at 15 mph through Saturday. On Sunday, a trough of low pressure diving southwards over the Eastern U.S. will weaken the steering currents over the Western Caribbean and cause 95L to slow and turn more to the north. 95L will begin a period of slow and erratic movement on Sunday that may last many days, as the storm wanders in the Western Caribbean and over Belize, Honduras, and Mexico's Yucatan Peninsula. If the center of 95L spends significant time over water, the storm could easily develop into powerful and dangerous Hurricane Matthew. If the center remains mostly over land, 95L will still generate extremely heavy rains over Central America, but remain below hurricane strength. By late next week, the trough of low pressure over the Eastern U.S. may lift out, allowing a ridge of high pressure to build in and force 95L westwards across the Yucatan Peninsula and into the Gulf of Mexico's Bay of Campeche. Alternatively, the trough of low pressure over the Eastern U.S. may amplify, drawing 95L northwards across Western Cuba and into Florida. The uncertainties in the long-range fate of 95L are high, and depend strongly on slight variations in its track that determine how much time the storm spends over land. One measure of the uncertainty in 95L's future track can be gained by viewing the ensemble forecast from the GFS model. An ensemble forecast is generated by taking the initial conditions in the atmosphere and making slight variations in the temperature, pressure, and humidity fields. Twenty or so tweaks of the initial conditions are made, and the GFS model run twenty separate times for each new set of initial conditions. The resulting ensemble of model runs gives one an idea of how sensitive the future track of the storm might be to errors in characterizing the initial state of the atmosphere. As one can see from this morning's GFS ensemble run (Figure 2), there are a wide range of possibilities for where 95L might go. The main thing I am confident of at this point is that 95L will generate very heavy rains over Nicaragua, Honduras, Belize, and Mexico's Yucatan Peninsula Friday through Tuesday that will likely cause dangerous flooding rains and life-threatening mudslides.
Tropical Depression Lisa
Tropical Depression Lisa continues to churn the waters of the far Eastern Atlantic. By Saturday night, upper level winds out of the west are expected to increase, bringing high wind shear of 20 - 45 knots over Lisa. The high shear may be capable of destroying the storm by early next week. It appears unlikely that Lisa will affect any land areas.
Elsewhere in the tropics
The remnants of Hurricane Julia are still spinning over the far Eastern Atlantic, and are generating some sporadic heavy thunderstorm to the north of the center of circulation. Julia's remains are being given a 10% chance of re-developing by NHC. There are no other threat areas to discuss, and none of the models is calling for development (except for 95L) over the next seven days.
Hurricane Karl's moisture causing flooding in Minnesota, Wisconsin
A plume of very moist air associated with what was Hurricane Karl last week has surged northwards over the Central U.S. over the past two days. This moisture is now being lifted over a warm front draped over Minnesota and Wisconsin, and has generated flooding rains in excess of six inches in southern Minnesota this morning. Flood warnings and flood watches are posted for a wide swath of the upper Midwest today, including most of Minnesota, northern Wisconsin, and Michigan's Upper Peninsula. The latest forecast discussion from the NWS office in Minneapolis notes that the forecast amount of moisture in the air this afternoon is similar in magnitude to the all-time record for this time of year (set on September 2, 1953.) These kinds of rain events are called Predecessor Rain Events (PREs), because they typically precede the actual arrival of the rain shield of a tropical storm.
Figure 3. Radar estimated rainfall over Minnesota.
Next post
I'll have an update on 95L later today. The timing will depend upon what the Hurricane Hunters find.
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 — Blog Index
I don't think so.
However, what about this?
I wonder. You look at the 12z GFS at around 72 hours out. There's a 1004mb low around the East Pacific.
Trace that energy really closely and it comes out on the Atlantic side. That somehow ends up becoming the GFS' storm.
I don't know whether it's just eyes screwing up or it does something with the heat low, I don't know. Or just some phantom storm it wants to spin up (because models never do that...)
Anyone else spot it?
Given that ECMWF is also in the same boat as GFS we can safely state that multiple vortices will embedded within 95L circulation in which a piece of energy will go W into C America while another piece will be left behind.
I guess you almost see it now by the current presentation of 95L and the current HH observations.
The center appears to have jumped, we'll have to way until they come from the SW to see where the center is now... IMO.
to paraphrase: poop hits the fan.
LOL... I guess so.
Discount the intensity for now.
You can seen the cloud tops warming on the north half of the circulation. This will be a disruption of strenghthening at the very least.
It's well organized now, with strong 850 vorticity and may get upgraded to a TD/TS, but won't strengthen much in the next 24 hours at least.
AVN LOOP
A decent track. I like the jam into central America and then the abrupt but slow turn north.
15 is high tailing it to the W.
This is going to be a real interesting situation to follow over the next few weeks. Thanks for the update Levi.
I see similar. If you "rock" the GFS 850mb vorticity you can see it origonates in the Costa Rica/Panama area.
Center Fix Coordinates: 13°48'N 75°56'W (13.8N 75.9333W
95L sure is fun to track... this one keeps you guessing.
I sure agree with you there. That was just me being un-specific @ 360hrs.
Link
A jammed track into central America that doesn't get out is always possible, but as the GFS shows you would likely just get new low pressure to form to the northeast over the western Caribbean, because again, the pattern can't avoid getting this heat out of there. Somehow, some way, we are going to get a tropical cyclone to come north out of the Caribbean. I still think Matthew is mostly likely to get drawn north by the trough and the central gulf coast eastward is the area threatened. Again though I will say that given the fragility of the situation nobody should let their guard down in case something changes, which could very easily happen.
It's not .. mentioned it before.. 95L goes into Belieze most likely and leave a broad area of low pressure north of honduras
Or the center fixes are to determine the direction of travel ?
IRLOOPLink
In addition to this, any cooling in the caribbean is temporary, as the prevailing currents keep bringing in hot water from the east caribbean and west atlantic hottub.
FULL IMAGE***
That would be because of the trough running down to get it before it loses it to central America lol.
At least that vortex message showed a temperature difference outside/inside the "eye", although only 1C. The previous vortex showed no difference.
I got to handed to NOGAPS... it has been one of the cleanest run consistency it has showed in quite sometime and it might actually have a good handle on 95L... interestingly is not too far off from the OFCL.
The Euro from the 00z run also has a closed isobar just off Costa Rica in about 72 hours. Of course, as it only does it in 12-24 hour segments, it's much more difficult to tell whether the energy crosses over or not.
If it did, it's hardly impossible considering how ex-TD11-E played a part in Hermine.
We're getting somewhere...
Also, with all this talk about Matthew possibly dissipating over Central America, I assume that track could rapidly change if Matthew intensifies? Meaning, he could move north or north of due west, catch the trough then head into the warm waters of the EGOM?
Two more things. First, there is talk of a possible upper level low (sorry if I sound dumb) next to Matthew if he makes it into the GOM, that it could impart high wind shear. Do you see this possible? Second, once Matthew catches the trough (which looks to be quite strong), would he take a turn due north or NE or NNE?
Thanks Levi and sorry for the long post.
I'm at work, so I have to be sneaky quick. So are y'all thinking we could end up with 2 separate cyclones? Forgive me I'm reading into it all wrong. I haven't looked at models or satellite yet this am
We're waiting for that to happen here. Flood watches all over the place. After that, gusts of 60mph when the front goes by. Love the big lake.
The track is again impossible to nail down right now as the models always have a hard time dealing with cut-off upper lows, and since the main steering influence on Matthew is likely to be a cut-off upper low, we are going to see a lot of different things show up on the models.
Yes an upper trough digging down may cause some wind shear and dry air which would be moderating factors in the Gulf of Mexico.
I think no matter what the trough does something is going to get drawn north out of the Caribbean next week, somehow. We'll see how it goes. Given the monsoonal nature of Matthew's development it wouldn't be a stretch to imagine new low centers forming while he is dealing with central America, but we'll see.
Not really "cyclones" but more like 2 entities (vortices) within one larger mass (95L). Now, the end result is that one of these could take over at one point or the other and therefore become a TD/TS, but we'll need to see as the days goes through.
I don't think we've had the wind gusts, except for when the front first entered the area early Tuesday morning - had some good thunderstorms and ping-pong ball sized hail in parts of St. Paul that morning. I'm just happy that it isn't cold enough to be snowing - we'd have about 10 feet by now! Yuck.
That's what a model or two is starting to show. I'll believe it when I see it, but this forecast looks plausible to me.
IF the 2 vortices scenario is valid. Is it possible for one to out run the other and leave both intact? I think there was something like that in a few of the GFS runs.
Viewing: 551 - 601
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 — Blog Index