Finnally better weather in Puerto Rico (Edited)

[cycloneye]

CARIBBEAN SEA...
A RATHER WET REGIME APPEARS TO BE SETTING UP FOR THE NE
CARIBBEAN AS THE REMAINS OF A FRONT SETTLE INTO THE HISPANIOLA
AREA IN THE NEXT COUPLE OF DAYS. UPPER JET ENERGY WILL BE IN
THE VICINITY AND COMBINED WITH THE DEEP MOISTURE VALUES COULD
PRODUCE VERY HEAVY RAINS FOR THE GREATER ANTILLES E OF CUBA THRU
PUERTO RICO AND THE LEEWARD ISLANDS N OF 17N. HEAVY RAINS...
FLASH FLOODING AND MUDSLIDES COULD OCCUR THIS WEEK IN THE HIGH
TERRAIN OF HISPANIOLA AND PUERTO RICO... DEPENDING ON THE EXACT
TRACK OF A WEAK NON-TROPICAL LOW PRESSURE AREA THAT COULD
DEVELOP NEAR THE DOMINICAN REPUBLIC BY MID-WEEK.[b]



[b]LOOKING AHEAD...MODEL GUIDANCES ARE SHOWING A SIGNIFICANT INCREASE
IN THE MOISTURE FIELD TOWARD MID WEEK. RAINFALL AMOUNTS BETWEEN 1
AND 3 INCHES OF RAIN MAY BE LIKELY ON LOCALIZED AREAS...BUT MAINLY
ACROSS THE U.S. VIRGIN ISLANDS AND THE EASTERN HALF OF PUERTO RICO.
WILL WAIT AND SEE HOW THIS PANS OUT.

The above is an excerpt of discussion from NWS in San Juan.
Models are showing a rather wet scenario for the Caribbean area including the formation of a low pressure.

http://met.psu.edu/tropical/tcgengifs/

Link above to models,GFS,CMC,Nogaps which show at latest runs this.

In summary let's watch the Caribbean in the comming days to see what evolves from this.Will there be more than rain with this? Stay tuned

[Anonymous]

Didn't this happen around one year ago?

[cycloneye]

Didn't this happen around one year ago?

Yes the Haiti strong low pressure which caused many deaths there.That is why I say let's watch what will occur with this.

[cycloneye]

...TROPICAL WAVES...

TROPICAL WAVE INTRODUCED ALONG 31W S OF 15N MOVING W 10-15 KT.
TIMESECTIONS FROM DAKAR SHOWED A DISTINCT MID-LEVEL WAVE PASSAGE
TWO DAYS AGO WHILE EVEN THE SAL OBSERVATION DISPLAYED A SIMILAR
PATTERN. THE GFS SEEMS TO HAVE A GOOD HANDLE ON THE WAVE IN
ADDITION TO A SLIGHT KINK IN THE ITCZ MARKING THE WAVE'S
LOCATION. CONVECTION IS LIMITED TO THE ITCZ.

This new wave will reach the Caribbean and interact with what will be already in the Caribbean and make things more wetter for the Islands.

[Yankeegirl]

You can send all that wet weather to HOuston if you dont want it... lol...

[cycloneye]

LONG TERM....GFS MODEL GUIDANCE AND FORECAST SOUNDINGS CONTINUE TO
SUGGEST A SIGNIFICANT INCREASE IN THE MOISTURE FIELD AT ALL LEVELS
WITH SUPPORTING UPPER LEVEL DYNAMICS COMMENCING MID WEEK AND
CONTINUING INTO THE UPCOMING WEEKEND. THIS WILL THEREFORE INCREASE
THE LIKELIHOOD OF SHOWERS AND THUNDERSTORM ACTIVITY ALONG WITH THE
CHANCE OF URBAN AND RIVER FLOODING. WILL HAVE TO CLOSELY MONITOR
THIS SITUATION OVER THE NEXT FEW DAYS AND SEE HOW THIS WEATHER
PATTERN UNFOLDS. ALL IN ALL IT LOOKS LIKE AN OVERALL WET WEATHER
PATTERN IS IN STORE FOR THE LATTER PART OF THE WEEK.

The above from the NWS in San Juan.



A broad but not a strong low pressure forms in the caribbean according to the GFS model.

[cycloneye]

ALL THE ATTENTION THIS FORECAST PACKAGE IS ON THE POTENTIAL
FOR HEAVY RAINFALL WEDNESDAY THROUGH FRIDAY. MODEL GUIDANCES ARE
SHOWING A SIGNIFICANT INCREASE IN THE MOISTURE VALUES BY MID WEEK AS
A FRONTAL BOUNDARY OR SURFACE TROUGH SETTLES NEAR OR ACROSS
DOMINICAN REPUBLIC...PUERTO RICO AND THE U.S. VIRGIN ISLANDS. SMALL
LOW PRESSURE VORTICES MAY DEVELOP ALONG THIS BOUNDARY...ENHANCING
THE SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE LOCAL REGION.
PERIODS OF HEAVY RAINFALL CAUSING SOME LOCALIZED FLOODING WILL BE
POSSIBLE. AS THE SOIL BECOMES MORE SATURATED...FLASH FLOODING AND
MUD SLIDES WILL ALSO BECOME LIKELY IN AREAS WITH THE HEAVIEST
AFTERNOON RAINFALL...ESPECIALLY THURSDAY AND FRIDAY. THIS TYPE OF
WEATHER EVENT SHOULD BE MONITORED CLOSELY.




18 UTC GFS shows broad low pressure in the Caribbean Sea but nothing that looks to be of anything tropical at this time only a good deal of rain for the Caribbean.By the way at grafic a low shows up off western Africa.

[cycloneye]

THE MOST IMPORTANT FEATURE ON OUR FORECAST IS THE WELL DEFINED LOW
PRESSURE LOCATED AT AROUND 39.6N AND 65.3W. THE SYSTEM IS NOT ONLY
THE SWELL SOURCE THAT IS AFFECTING OUR LOCAL ATLANTIC WATERS IS ALSO
HELPING PULL MOISTURE FROM THE EQUATOR TO OUR REGION. ALL MODELS ARE
SUGGESTING THIS MOIST PATTERN WILL PERSIST THROUGH THE WEEKEND. THIS
WILL ENHANCE SIGNIFICANTLY THE SHOWER AND THUNDERSTORMS ACTIVITY
OVER LAND DURING THE AFTERNOON HOURS AND OVER WATERDURING THE NIGHT
HOURS.

[Anonymous]

18 UTC GFS shows broad low pressure in the Caribbean Sea but nothing that looks to be of anything tropical at this time only a good deal of rain for the Caribbean.By the way at grafic a low shows up off western Africa.

Could this low off africa be the first tropical wave of the season?

[cyclonaut]

Not much happening as of now.

[cycloneye]

18 UTC GFS shows broad low pressure in the Caribbean Sea but nothing that looks to be of anything tropical at this time only a good deal of rain for the Caribbean.By the way at grafic a low shows up off western Africa.

Could this low off africa be the first tropical wave of the season?

At grafic above is the tropical wave parade and there haved been 3 waves so far in 2005 as the numbers show as 02 for the Caribbean Wave at the blue line and 03 for the Atlantic one with the blue line.There is a 04 meaning that a new wave will be introduced this evening.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
340 PM AST MON MAY 9 2005

.DISCUSSION...SINCE THE LATE MORNING AND EARLY AFTERNOON
HOURS...CLOUDINESS DEVELOPED ACROSS MOST OF THE AREA OF PUERTO
RICO...VIEQUES AND CULEBRA WITH LESS ACTIVE WEATHER NOTED OVER THE
U.S. VIRGIN ISLANDS. A PRE-FRONTAL TROUGH OVER PUERTO RICO
ASSOCIATED TO THE STATIONARY FRONTAL BOUNDARY OVER EASTERN
HISPANIOLA IS ENHANCING THE SHOWER ACTIVITY. THIS FRONTAL BOUNDARY
IS TIED TO A LOW PRESSURE CENTER...ESTIMATED NEAR 39 DEGREES
NORTH...AND 65 DEGREES WEST. UNDER THIS SCENARIO...MOISTURE IS BEING
PULLED FROM THE LOWER TO THE HIGHER LATITUDES ALONG THE BOUNDARY
WHICH LIES OVER THE LOCAL ISLANDS. GUIDANCE SUGGEST THAT ABUNDANT
MOISTURE WILL CONTINUE TO FLOW OVER THE AREA WITH A TREND IN THE
LOCAL AIRMASS TO BECOME MORE SATURATED. THIS SHOULD BE MORE
NOTICEABLE BY MID TO END OF THE WEEK. BESIDE THIS...GUIDANCE SUGGEST
A SERIES OF PULSES OR SHORT WAVES MOVING ALONG THE BOUNDARY...OVER
THE LOCAL AREA. THIS SCENARIO IS ONE IN WHICH SIGNIFICANT RAINFALL
AND FLASH FLOODING ARE VERY POSSIBLE.

ALTHOUGH THERE CAN BE CHANGES BETWEEN ACTUAL AND FUTURE MODEL
GUIDANCE THE SEVERITY OF THE EVENT SHOULD KEEP ALL THE PEOPLE IN THE
AREA MONITORING THE PROGRESS OF THIS SITUATION.

Well it looks like a done deal the rain event as above afternoon discussion from the NWS in San Juan says.And the model guidance supports this scenario but nothing that may turn into a tropical entity from this as this time however let's keep an eye just in case something decides to form from this mess.



12z GFS at 96 hours




12z GFS at 120 hours.Broad low pressure continues over the Caribbean Sea but nothing tropical.

[cycloneye]

MODEL GUIDANCE CONTINUES TO SHOW A SIGNIFICANT INCREASE IN THE
MOISTURE FIELD TO OCCUR AFTER WEDNESDAY AS WEAK LOW PRESSURE CENTERS
FORM NEAR THE AREA. THIS WILL ENHANCE SHOWER AND THUNDERSTORMS
DEVELOPMENT THROUGH THE WEEKEND.

REST OF THE WEEK...WE WILL CONTINUE TO BE UNDER THE INFLUENCE OF A
QUASI STATIONARY BOUNDARY THROUGH AT LEAST THE BEGINNING OF NEXT
WEEK. GUIDANCE ALSO SUGGEST A SERIES OF PULSES OR SHORT WAVES MOVING
ALONG THE BOUNDARY. THESE FEATURE WILL HELP THE SOUTHWEST MOISTURE
INFLUX TO OCCUR ENHANCING THE SHOWER AND THUNDERSTORM DEVELOPMENT
ACROSS THE CARIBBEAN BASIN.

[cycloneye]

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

A very interesting loop of the 12z GFS model which shows a low pressure moving from the Caribbean into the Atlantic and deepening.The only thing to do is watch how all of this evolves in the next couple of weeks.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
315 PM AST TUE MAY 10 2005

.DISCUSSION...MODEL GUIDANCE CONTINUE TO SUGGEST THE WET PATTERN
TREND BEING MENTIONED SINCE SEVERAL DAYS AGO. SOME VARIATIONS
HOWEVER...ARE POSSIBLE MAINLY RESPECT WHERE AND WHEN OVER THE AREA
THE HEAVIEST RAINFALL IS GOING TO DEVELOP.

A STRONG LOW PRESSURE SYSTEM LOCATED NEAR 37 DEGREES NORTH AND 65
DEGREES WEST...WILL CONTINUE TO PULL MOISTURE FROM THE LOWER TO THE
HIGHER LATITUDES. ALONG THE FRONTAL BOUNDARY EXTENDING FROM THE
EASTERN PORTION OF HISPANIOLA NORTHEAST INTO THE ATLANTIC AND TIED
TO THE AFOREMENTIONED LOW. SINCE THIS BOUNDARY HAS BECAME STATIONARY
A MOISTURE FLOW WILL CONTINUE ACROSS THE LOCAL ISLANDS AND WATERS.
THE ABUNDANT MOISTURE ASSOCIATED TO THESE FEATURES ALONG WITH A
STRONG UPPER LEVEL JET...UPPER LEVEL DIFFLUENCE AND DIVERGENCE IS
EXPECTED TO RESULT IN VERY UNSTABLE ATMOSPHERIC CONDITIONS. THIS
WILL LEAD TO SCATTERED TO NUMEROUS SHOWERS...POSSIBLY HEAVY AND HIGH
CHANCES FOR URBAN AND/OR FLASH FLOODING.

[x-y-no]

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/index_slp_s_loop.shtml

A very interesting loop of the 12z GFS model which shows a low pressure moving from the Caribbean into the Atlantic and deepening.The only thing to do is watch how all of this evolves in the next couple of weeks.

Wheeee!

Take a look at the upper and mid level at 162 hours, when this thing is supposed to be deepening:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/fp0_162.shtml

I'll tell you - sometimes I just can't figure out what the GFS is doing ...

Not that I'm one of those "bash the GFS all the time" guys - I think it's a valuable tool. But you gotta do a reality check on it now and then.

Jan

[cycloneye]

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/index_slp_s_loop.shtml

A very interesting loop of the 12z GFS model which shows a low pressure moving from the Caribbean into the Atlantic and deepening.The only thing to do is watch how all of this evolves in the next couple of weeks.

Wheeee!

Take a look at the upper and mid level at 162 hours, when this thing is supposed to be deepening:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/fp0_162.shtml

I'll tell you - sometimes I just can't figure out what the GFS is doing ...

Not that I'm one of those "bash the GFS all the time" guys - I think it's a valuable tool. But you gotta do a reality check on it now and then.

Jan

Dont worrie about it Jan as I not look only at the GFS. Other models show almost the same scenario.

http://www.meteo.psu.edu/~arnottj/cgi-b ... =Animation

CMC model for 72 hours shows broad low pressure in the Caribbean with the wet pattern setting up.

[x-y-no]

Dont worrie about it Jan as I not look only at the GFS. Other models show almost the same scenario.

http://www.meteo.psu.edu/~arnottj/cgi-b ... =Animation

CMC model for 72 hours shows broad low pressure in the Caribbean with the wet pattern setting up.

I'm not worried - just having a little chuckle.

Oh ... and I wasn't questioning the broad low and the wet pattern setting up in the Carribean - I'm fairly sure that'll happen. I was referring specifically to the deepening of the low which the GFS does in the long range. That looks kind of unlikely given the upper and mid-level setup the model predicts at that time.

Obviously, looking 162 hours out is a chancy business with any of the models - but at this time of year I always start looking at them to get a feel for what the biases may be this year (since they tweak the models each year, one can't count on the biases being tha same as in prior years).

Jan

[cycloneye]

Dont worrie about it Jan as I not look only at the GFS. Other models show almost the same scenario.

http://www.meteo.psu.edu/~arnottj/cgi-b ... =Animation

CMC model for 72 hours shows broad low pressure in the Caribbean with the wet pattern setting up.

I'm not worried - just having a little chuckle.

Oh ... and I wasn't questioning the broad low and the wet pattern setting up in the Carribean - I'm fairly sure that'll happen. I was referring specifically to the deepening of the low which the GFS does in the long range. That looks kind of unlikely given the upper and mid-level setup the model predicts at that time.

Obviously, looking 162 hours out is a chancy business with any of the models - but at this time of year I always start looking at them to get a feel for what the biases may be this year (since they tweak the models each year, one can't count on the biases being tha same as in prior years).

Jan

Yeah I know what you mean.The famous Phanthom Lows that they create many times.

[weatherwindow]

just a little jab at the GFS... one of the senior forecasters at key west used to call it the "disney" model....persistent convective feedback problem, i dont think it was ever really solved....however, in this case, it is being backed up by nogaps. 1007/8 mb low sw of jamaica by sunday then moving over hispaniola mon/tues. as mentioned in an earlier post...this could be repetiition of late may 2004 for haiti...what they wouldnt give for a few more trees on those hillsides. instead of funding another retirement home in france for another haitian president, the world bank should fund the planting of those trees and an effective rural communications system for getting people out of harms way.......rich