Global Model Runs for W.Caribbean Early Season Development

[gatorcane]

Aric the low seems to be moving north slowly along the Nicaraguan coastline. Is that what you are seeing?

[Aric Dunn]

Aric the low seems to be moving north slowly along the Nicaraguan coastline. Is that what you are seeing?

it appears that way .. but i need more images.. but its going to meander around anyway they both are.. and if there is some interaction between the two lows there will be this exact type of motion .. 90E is moving ene and the other low is moving n or nnw .. we to watch it.. again we will probably see center consolidate somewhere ..

[micktooth]

Well I think you have got to hand it to the models. They were picking up on something days ago, before there were any cloud formations at all.

[Aric Dunn]

Well I think you have got to hand it to the models. They were picking up on something days ago, before there were any cloud formations at all.

yep especially the gfs

[Frank2]

But - will the convection still be there, 6 or 12 hours from now?

We'll see...

[ronjon]

Interesting TPC discussion about the two low centers.


East Pacific Tropical Weather Discussion
--------------------------------------------------------------------------------


000
AXPZ20 KNHC 281541
TWDEP

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAY 28 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1515 UTC.

...SPECIAL FEATURES...
SURFACE LOW PRES...POSSIBLE TRPCL CYCLONE WITHIN NEXT 36-48 HRS
...AT 10N88W 1006 MB GETTING MORE LOW LEVEL ORGANIZATION WHILE
SLOWLY IMPROVING UPPER LEVEL OUTFLOW. LITTLE MOVEMENT AT THIS
TIME BUT SYSTEM IS EXPECTED TO DRIFT NE AS SECOND LOW PRES OVER
SW CARIBBEAN INTERACTS WITH IT. ASSOCIATED STRONG CONVECTION
AFFECTS S NICARAGUA AND MOST OF COSTA RICA AND PANAMA.
CONDITIONS BECOMING MORE FAVORABLE FOR FURTHER STRENGTHENING
WITH PLENTY OF WARM MOIST TRPCL AIR MASS INFLUX FROM THE SW.
WIND INCREASING TO 25 KT AND GUSTY WITHIN 150 NM S AND SE
QUADRANTS. HEAVY RAINFALL POTENTIAL EXPECTED OVER MUCH OF
CENTRAL AMERICA S OF MEXICO TO PANAMA WITHIN NEXT 48 HOURS.

INTERACTION BETWEEN BOTH LOW PRES CENTERS ADDS UNCERTAINTY TO
DEVELOPMENT FORECAST AND THEIR TRACKS...BUT PROXIMITY TO LAND
AREAS COULD CURTAIL SIGNIFICANT DEVELOPMENT OF EITHER ONE FOR
THE TIME BEING. COMPOUNDING THE SCENARIO IS TRPCL WAVE ALONG
80W DISCUSSED BELOW WHICH IS LIKELY BOOST THE PROBABILITY OF
INTENSIFICATION AS MUCH AS TO THE UNCERTAINTY OF ANY FORECAST.

[Aric Dunn]

Interesting TPC discussion about the two low centers.


East Pacific Tropical Weather Discussion
--------------------------------------------------------------------------------


000
AXPZ20 KNHC 281541
TWDEP

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAY 28 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1515 UTC.

...SPECIAL FEATURES...
SURFACE LOW PRES...POSSIBLE TRPCL CYCLONE WITHIN NEXT 36-48 HRS
...AT 10N88W 1006 MB GETTING MORE LOW LEVEL ORGANIZATION WHILE
SLOWLY IMPROVING UPPER LEVEL OUTFLOW. LITTLE MOVEMENT AT THIS
TIME BUT SYSTEM IS EXPECTED TO DRIFT NE AS SECOND LOW PRES OVER
SW CARIBBEAN INTERACTS WITH IT. ASSOCIATED STRONG CONVECTION
AFFECTS S NICARAGUA AND MOST OF COSTA RICA AND PANAMA.
CONDITIONS BECOMING MORE FAVORABLE FOR FURTHER STRENGTHENING
WITH PLENTY OF WARM MOIST TRPCL AIR MASS INFLUX FROM THE SW.
WIND INCREASING TO 25 KT AND GUSTY WITHIN 150 NM S AND SE
QUADRANTS. HEAVY RAINFALL POTENTIAL EXPECTED OVER MUCH OF
CENTRAL AMERICA S OF MEXICO TO PANAMA WITHIN NEXT 48 HOURS.

INTERACTION BETWEEN BOTH LOW PRES CENTERS ADDS UNCERTAINTY TO
DEVELOPMENT FORECAST AND THEIR TRACKS...BUT PROXIMITY TO LAND
AREAS COULD CURTAIL SIGNIFICANT DEVELOPMENT OF EITHER ONE FOR
THE TIME BEING. COMPOUNDING THE SCENARIO IS TRPCL WAVE ALONG
80W DISCUSSED BELOW WHICH IS LIKELY BOOST THE PROBABILITY OF
INTENSIFICATION AS MUCH AS TO THE UNCERTAINTY OF ANY FORECAST.

lol that has the most uncertainties i have ever seen an a discussion ...

[gatorcane]

well the Nicaraguan low does appear to gradually becoming better organized IMHO as it drifts N or NNW. It does apear it is trying to "wrap" in moisture from the extreme SW Caribbean and 90E.

I don't know about you all, but I don't want this Nicaraguan low to take over because it would have alot of real estate in front of it with plenty of moisture and an environment that is becoming increasingly favorable.

[Evil Jeremy]

After a long and confusing GFS run, the end result is still a strike at SFL

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_228l.gif

[Frank2]

But, if the model is currently targeting extreme SFL, then that means a more likely chance that'll move NE across Cuba - the models always initialize with a further west track at this time of year...

[gatorcane]

After a long and confusing GFS run, the end result is still a strike at SFL

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_228l.gif

The GFS has been pretty consistent about that. Over the past day or so, it seems to have become less certain but one thing about the GFS that I have noticed is that it can deviate for a couple of days only to return to a solution it made previously.

BTW there is a weakness expected to develop early next week, it's probably what the GFS is picking up on:

NWS Miami discussion snippet:

LONG TERM (SATURDAY THROUGH TUESDAY)...RIDGE HOLDS IN PLACE OVER
NORTHEAST GULF ON SATURDAY WITH A DAY SIMILAR TO FRIDAY EXPECTED.
TROUGH OVER EASTERN UNITED STATES WILL BEGIN TO ERODE EASTERN
PORTION OF RIDGE ON SUNDAY...WHICH WILL HELP TO SLIGHTLY INCREASE
MOISTURE AND INSTABILITY FOR THE REMAINDER OF THE FORECAST PERIOD
AS WINDS BECOME MORE SOUTHEAST.

[Ed Mahmoud]

After a long and confusing GFS run, the end result is still a strike at SFL

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_228l.gif

Go out a bit that is a Panhandle/Alabama landfall of a fairly weak system that brings beneficial rain to all of Florida, nearly eliminating the chance of wildfires for any major sporting events in East-Central Florida early in July.

[gatorcane]

Latest IR image shows the 90E cloud tops warming pretty significantly well there is a noticeable "bend" to the cloud tops around the Nicaraguan low.....I wonder if this is a trend? The 90E convection seems to be elongating in the direction of the Nicaraguan low....hmm interesting?

[Thunder44]

This is from Jeff Masters' discussion today on 90E and Carribean development:


Major flooding likely in Central America from 90E
An area of low pressure (90E) in the Eastern Pacific off the coast of Costa Rica, near 10N 88W, is steadily organizing and appears likely to develop into a tropical depression later today or tomorrow. The National Hurricane Center is currently assigning a "High" probability (>50% chance) that this will be a tropical depression, in its new experimental Tropical Weather Outlook. Satellite loops show that the low has developed a very large and expanding circulation. This circulation is likely to expand across Central America into the Western Caribbean, allowing the storm to tap moisture from the Atlantic and Pacific. Storms that are able to tap the moisture sources of both oceans can be extremely dangerous rainmakers, even if they are weak tropical depressions. Already, 90E is generating very heavy rains in excess of six inches per day near its center. The storm is expected to move northeastward over Costa Rica or Nicaragua by Thursday or Friday, and should being dangerous flooding rains of 5-10 inches to those nations and Panama. Most of the computer model guidance suggests that the storm will then track to the north, spreading very heavy rains across Guatemala, El Salvador, Honduras, Belize, and southern Mexico by Saturday. These heavy rains will cause life-threatening flash flooding, particularly in mountainous regions.

Since 90E is beginning to dominate the circulation pattern of the region, it appears unlikely that a tropical depression will form in the Western Caribbean in the coming week, as some computer models have been predicting. It is possible that 90E could cross Central America and pop out in the Western Caribbean near the Yucatan Peninsula, or in the Gulf of Mexico's Bay of Campeche. However, the crossing of Central America will severely disrupt the storm, and the odds of 90E becoming a depression in the Atlantic basin are low.

[Frank2]

You all do realize that this is just one large system, not the two many are following...

[KWT]

Yeah gatorcane something curious is going on in that region. 90E still looks good but the convective burst that has now stayed in place for the last 36hrs and drifted northward does look interesting, esp with a weak low estimated to be present just to the west of that area.

I'm still wondering whether we will see one center try and absorb the other one or not?

Frank, yep its all one large broad circulation but there are several center present with it.

[Frank2]

Yes, that's what I just mentioned - it looks more like one large disturbance...

P.S. Say a prayer for Jim, our old NHEML/HRD Program Assistant, who passed away in his sleep yesterday morning...

[gatorcane]

One thing is for sure, the Caribbean energy is making a good push to the North this afternoon.....I would say its surging north pretty rapidly.

[gatorcane]

It looks like 90E's "center" is jumping ENE, I see a vorticity trying to move ashore looking at this visible loop. I think 90E has not organized any better today and think the Nicaraguan low is influencing 90E more than we think....

http://www.ssd.noaa.gov/goes/flt/t6/loop-vis.html

[KWT]

Yep the energy is certainly heading northwards at a decent clip, I'm pretty sure this is the area the GFS was developing over the last 7 days or so, timing seems about right as well.

As for the EPAC system, hard to tell if the center has moved that much to the ENE though the current track would move it into that region.