Area of disturbed weather in the Caribbean

[Ed Mahmoud]

I don't know if I trust the NAM near the edge of its territory, since IIRC boundary conditions are supplied from the previous GFS run, so near thr edge of the domain the NAM might lean towards the GFS.



I could be wrong however, and Derek's point that the watchdog that barks at mice and monsters alike, the Canadian, is silent.

[ronjon]

I don't know if I trust the NAM near the edge of its territory, since IIRC boundary conditions are supplied from the previous GFS run, so near thr edge of the domain the NAM might lean towards the GFS.



I could be wrong however, and Derek's point that the watchdog that barks at mice and monsters alike, the Canadian, is silent.

Ed, I see Derek's point about the CMC and HPC mentioned it today in their discussion. The NAM has a rather poor track record for tropical systems but seemed to do well with that extratropical low that dropped buckets of rain on FL a few weeks ago which eventually tracked into S Miss. I don't know if they did any tweaks to the code over the off season but we'll see this year.

General support from the Euro and NOGAPs in addition to these two models, plus a weak circulation/deep convection in the sw caribbean, and climotology is increasing my confidence that something may form in the next 3 to 5 days.

From HPC this afternoon:

SOUTHWARD GFS/DGEX/ECMWF STILL INSIST UPON TROPICAL DEVELOPMENT
MID PERIOD IN THE WESTERN CARRIBEAN OFF NICARAGUA/HONDURAS WITH A
GENERAL NWD TRACK TOWARDS WRN CUBA. THIS MODEL DEVELOPMENT HAS
BEEN SEEN FOR SEVERAL DAYS AND MORE. EARLIER THIS SEASON LONGER
RANGE GFS/ECMWF DID WELL IDENTIFYING LOW LATITUDE POTENTIAL
TROPICAL DEVELOPENT BUT IN THOSE CASES THE ORIGINAL SYSTEM WAS
MORE BAROCLINIC INTIALLY. THIS WOULD BE COMPLETELY TROPICAL AND
THIS TYPE OF CYCLOGENESIS IS NOT HANDLED WELL BY THESE MODELS. THE
CMC NORMALLY A BULLISH TROPICAL AND MARITIME EXTRATROPICAL MODEL
WITH A HIGH FALSE ALARM RATIO IS NOT GENERATING MUCH OF A SYSTEM
AND CONTS TO WEAKEN CHANCES OF DEVELOPMENT. THIS WOULD LEAD US
INTO EVEN LOWER CONFIDENCE IN THIS GENERATION. IF WE HAVE SOME
DEVELOPMENT IT MAY INCREASE THE CHANCE OF RAIN LATE WEEKEND OVER
CUBA AND SOUTHERN FLORIDA. TPC/HPC COORDINATION PREFERENCE IS TO
LEAVE THIS AS A VERY SLOWLY DEVELOPING SYSTEM IN THE WRN CARRIBEAN
INITIALLY AS TROF THEN A SPOT LOW.

[senorpepr]

Canadian remains less than impressed.

[cycloneye]

Weaker than GFS but EURO has low in Caribbean.

12z ECMWF

Edit=I am sandwitched

[artist]

Canadian remains less than impressed.

so when should we have a better idea if this might transpire? How far out oare the models on this right now?

[tailgater]

Someone correct me if I'm wrong because I don't follow the models that much, I thought some changes were made to improve the CMC last year, were there any changes made to any of the Major models(ie GFS,CMC,EURO,UKMET and NOGAPS).
Thanks in advance.

[NDG]

Weaker than GFS but EURO has low in Caribbean.

12z ECMWF

Edit=I am sandwitched

Don't be, Luis.

Like I mentioned before, the euro has been persistent in lowering surface pressures and lowering UL shear starting the middle of next week through next weekend, sometimes that is more than enough indications from the euro that we could see development in that area.

[cycloneye]

Marine Discussion from TPC

000
AGXX40 KNHC 061945
MIMATS

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
345 PM EDT SAT JUN 06 2009


CARIBBEAN AND TROPICAL ATLC W OF 55W...
COMPUTER MODELS HAVE COME INTO MUCH BETTER AGREEMENT REGARDING
THE DEVELOPMENT OF A BROAD AREA OF LOW PRES OVER THE SW
CARIBBEAN. CONVECTION HAS STARTED TO INCREASE OVER THE AREA...
AND A QSCAT PASS FROM AROUND 1030 UTC THIS MORNING...ALTHOUGH
NEAR THE EDGE OF THE SWATH...SHOWED THAT WINDS ARE BEGINNING TO
VEER TO THE SE BETWEEN 70W AND 76W. FOR THIS FORECAST
PACKAGE...WILL CONTINUE WITH THE TREND OF BROAD LOW PRESSURE
FORMING OVER THE W CARIBBEAN LATE MON THROUGH THU WITH WINDS IN
THE 20 KT RANGE AND MAX SEAS OF UP TO 9 FT OVER THE NW
CARIBBEAN. WILL CLOSELY MONITOR FUTURE MODEL GUIDANCE TO SEE IF
THERE APPEARS TO A MORE DEFINITIVE CONSENSUS AS TO ANY POSSIBLE
UPCOMING POSSIBLE DEVELOPMENT WITH THIS FEATURE AS WELL AS ITS
FUTURE TRACK...PARTICULARLY SINCE THIS IS A FAVORABLE AREA FOR
TROPICAL CYCLONE FORMATION DURING THIS EARLY PORTION OF THE
SEASON.

http://www.nhc.noaa.gov/text/MIAMIMATS.shtml


HPC Discussion


SOUTHWARD GFS/DGEX/ECMWF STILL INSIST UPON TROPICAL DEVELOPMENT
MID PERIOD IN THE WESTERN CARRIBEAN OFF NICARAGUA/HONDURAS WITH A
GENERAL NWD TRACK TOWARDS WRN CUBA. THIS MODEL DEVELOPMENT HAS
BEEN SEEN FOR SEVERAL DAYS AND MORE. EARLIER THIS SEASON LONGER
RANGE GFS/ECMWF DID WELL IDENTIFYING LOW LATITUDE POTENTIAL
TROPICAL DEVELOPENT BUT IN THOSE CASES THE ORIGINAL SYSTEM WAS
MORE BAROCLINIC INTIALLY. THIS WOULD BE COMPLETELY TROPICAL AND
THIS TYPE OF CYCLOGENESIS IS NOT HANDLED WELL BY THESE MODELS. THE
CMC NORMALLY A BULLISH TROPICAL AND MARITIME EXTRATROPICAL MODEL
WITH A HIGH FALSE ALARM RATIO IS NOT GENERATING MUCH OF A SYSTEM
AND CONTS TO WEAKEN CHANCES OF DEVELOPMENT. THIS WOULD LEAD US
INTO EVEN LOWER CONFIDENCE IN THIS GENERATION. IF WE HAVE SOME
DEVELOPMENT IT MAY INCREASE THE CHANCE OF RAIN LATE WEEKEND OVER
CUBA AND SOUTHERN FLORIDA. TPC/HPC COORDINATION PREFERENCE IS TO
LEAVE THIS AS A VERY SLOWLY DEVELOPING SYSTEM IN THE WRN CARRIBEAN
INITIALLY AS TROF THEN A SPOT LOW.

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

[MiamiensisWx]

For what it's worth, the 18Z NAM brings the system over the Yucatan Peninsula:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/nam/18/images/nam_slp_066l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/nam/18/images/nam_500_084l.gif

[RL3AO]

One thing to watch is the tropical wave entering the Eastern Caribbean. It might help get something started when it gets there in a few days.

[ronjon]

NWS Miami AFD:

THE LONG RANGE MODELS ARE STILL SHOWING A WEAK LOW PRESSURE SYSTEM DEVELOPING IN THE WESTERN CARIBBEAN SEA LATE THIS WEEK AND MOVING NORTH SLOWLY TOWARDS THE SOUTHEAST GULF OF MEXICO OR THE FLORIDA STRAITS THIS WEEKEND. THIS WILL KEEP THE WINDS IN A EASTERLY WIND FLOW AND ALLOW FOR THE WINDS TO INCREASE TO BREEZY CONDITIONS...DUE
TO THE TIGHTENING OF THE PRESSURE GRADIENT. AT THE SAME TIME...SOME MORE MOISTURE WILL WORK INTO THE CWA AREA BY THIS WEEKEND. SO HAVE INCREASED THE POPS A LITTLE BIT OVER THE CWA FOR THIS WEEKEND.

[Derek Ortt]

the EC wave is not what is developing. It is the mess by Panama

[senorpepr]

06/21Z observations and satellite. Looks like the pressure is sub-1010 hPa.

Puerto Cabezas, Nicaragua, is reporting 1010.0 hPa (with 5km in light drizzle). Based on that, I'd estimate the pressure is probably around 1009 hPa.

[Vortex]

18Z GFS has quite a well organized system south of cuba..Several of the medium range models have been very consistent in formation of a TC over the western carribean. We now have lowering pressures, deeper convection over or near where the models depict initial development. From this point forward it should be quite interesting following the evoloution of this developing system. I think with warm enough SST's, climatologcally favored area, an improving environmental upper air pattern, model support, and now an area of deep convection with an associated low this all leads me to feel confident we have a decent shot at ana this upcoming week.

H+162 18Z GFS

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_162l.gif

[Vortex]

GFS 18Z GFS At H+174 continues well organized and moving north across central cuba and into the florida straits.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_174l.gif

H+192 well organized strong TS/Hurricane landfalling in southern florida
http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_192l.gif

H+228 continues well organized and moving north along the Florida central east coast.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_228l.gif

[brunota2003]

Talk about a strange way to hit Florida...as if it has not been hit from enough directions the past few years!

[cycloneye]

18 UTC Surface Analysis



http://www.opc.ncep.noaa.gov/UA.shtml

[wxman57]

Talk about a strange way to hit Florida...as if it has not been hit from enough directions the past few years!

Yeah, I'd go with that 18Z GFS track, for sure! First impulse is moving inland into Nicaragua now, taking the convection with it.

What really catches my eye is the low developing off the Carolinas along that front. I don't think it'll develop into anything tropical, but it sure is spinning up.

[cpdaman]

18Z GFS has quite a well organized system south of cuba..Several of the medium range models have been very consistent in formation of a TC over the western carribean. We now have lowering pressures, deeper convection over or near where the models depict initial development. From this point forward it should be quite interesting following the evoloution of this developing system. I think with warm enough SST's, climatologcally favored area, an improving environmental upper air pattern, model support, and now an area of deep convection with an associated low this all leads me to feel confident we have a decent shot at ana this upcoming week.

H+162 18Z GFS

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_162l.gif

yes and that is why even though there is legitamicy to say "well the CMC doesn't show anything yet".......that thought IMO should be extended to say BUT ......even though it gives alot of false alarms ....it may just be getting a late start on catching this system....given the other models and relatively low pressure in the area.....no?

also i'm ignornat on this....how much danger can a storm crossing cuba (south to north) pose to S.FL wind damage wise?......seems hits from the straight E or ESE are the worst.....followed by the SW (wilma) but from the south.....doesn't cuba usually knock these storms don't like 40%......anyone recall any bad storm to hit florida from close to DUE south?

[Extremeweatherguy]

also i'm ignornat on this....how much danger can a storm crossing cuba (south to north) pose to S.FL wind damage wise?......seems hits from the straight E or ESE are the worst.....followed by the SW (wilma) but from the south.....doesn't cuba usually knock these storms don't like 40%......anyone recall any bad storm to hit florida from close to DUE south?

Hurricane King (1950) - http://en.wikipedia.org/wiki/Hurricane_King



The storm crossed over Cuba and still managed to hit Miami as a Category 3 Hurricane with a pressure of 955mb. Miami reported wind gusts up to 150mph during the storm.

Hurricane Cleo (1964) - http://en.wikipedia.org/wiki/Hurricane_Cleo



This storm brought sustained winds of over 100mph and gusts to 130mph+ to the city of Miami.