Models Develop a Disturbance Near Florida (Is invest 90L)

[Tampa Bay Hurricane]

If the ridge builds strong enough...any mositure or low
would move west across the GOM after crossing FL...
it should bring moisture to NOLA and Texas in the 6-10 day
range...as for tropical it is too early to tell...but shear should
keep the winds at 45 mph or less IMO...
It is common early season to get a minimal TS or Minimal sub-TS...
Barry 2007 was tropical and strong in the SE Gulf but quickly became
extra-tropical as it moved further north into the GOM due to shear.
While the "low" may move west I still expect mid/upper level shear
to keep the intensity at a minimal TS/Subtropical Storm status at the MOST.
It may just remain a Tropical Depression though... (over
the next 4-10 day forecast)

[NDG]

Ed, a 1000mb low pressure as indicated by the euro in its 240h forecast is not depression. Is a moderate strength tropical or subtropical storm. Not to say that it will pan out.

[gatorcane]

I hate to burst bubbles but we've seen all of models predict something that never panned this far out on many occasions in the past and that was during the peak months of the season. We are not even in the "official" part of the season. Yeah I know anything is possible (like me winning the Texas lotto) but we know the odds are slim so lets put things into perspective here. We are talking about a phantom system 7-10 days out.

You have climatology on your side but note the ECMWF and UKMET show some kind of disturbance developing in the less than 7 day timeframe. I can tell you the UKMET is very conservative. If it is showing something, than my eyebrows will raise. Not only that but every model is showing something.

I doubt they will all be wrong. I'm not forecasting a hurricane in the GOM but some kind of consolidated area of disturbed weather, possibly subtropical or tropical developing is a decent possibility at this point with such excellent model consensus.

[NDG]

If the ridge builds strong enough...any mositure or low
would move west across the GOM after crossing FL...
it should bring moisture to NOLA and Texas in the 6-10 day
range...as for tropical it is too early to tell...but shear should
keep the winds at 45 mph or less IMO...
It is common early season to get a minimal TS or Minimal sub-TS...
Barry 2007 was tropical and strong in the SE Gulf but quickly became
extra-tropical as it moved further north into the GOM due to shear.
While the "low" may move west I still expect mid/upper level shear
to keep the intensity at a minimal TS/Subtropical Storm status.

May systems have most of their moisture well removed from their center to the N & E because of shear, this is the best case scenario for FL to get some much needed rain. If it eventually goes into the central gulfcoast, I doubt that TX will see much moisture out of it.

[Ed Mahmoud]

Ed, what makes you think that is subtropical? Looks very tropical to me.

Day 9 850 mb winds, which I'd assume are similar to surface winds, not concentrated near lowest pressure

[Tampa Bay Hurricane]

I agree it does appear likely that shear would push most of the
moisture NE of the center of the Low.

[cycloneye]

Tampa AFD

.LONG TERM (SUNDAY NIGHT - FRIDAY)...UNCERTAINTY REMAINS REGARDING
THE DEVELOPMENT AND FUTURE SOLUTION FOR THE LOW PRESSURE SYSTEM
THAT SEEMS TO FORM OVER NORTHERN CUBA ON WEDNESDAY. GFS HAS
SIGNIFICANTLY CHANGED ITS GENERAL SCENARIO WITH THE SURFACE
CIRCULATION LOOKING WEAKER AND WITH A TRACK FURTHER TO OUR WEST.
DGEX DEVELOPS A BETTER CLOSED LOW WITH M/L SUPPORT...BUT ACTUALLY
STEERS IT EVEN FURTHER TO OUR WEST BY THURSDAY. ECMWF REMAINS AS A
HAPPY MEDIUM BETWEEN THE PREVIOUS SOLUTIONS. THE INCREASINGLY
CONSISTENT SCENARIO IN ALL GUIDANCE IS THE ARRIVAL OF AN U/L
TROUGH ACROSS THE SOUTHEAST STATES ON MONDAY WHICH PUSHES A SFC
FRONTAL BOUNDARY INTO THE NE GULF. THIS FRONT SEEMS TO STALL JUST
TO OUR NW AND SHOULD HELP IN EXTENDING THE PATTERN OF UNSETTLED
WEATHER ACROSS THE AREA THROUGH THE LONG TERM. GUIDANCE POPS
CONTINUE TO INCREASE FOR MONDAY AND TUESDAY...AND DEPENDING ON THE
EVENTUAL SOLUTION FOR THE LOW FEATURE...THE AREA COULD EXPERIENCE
SOME VERY MUCH NEEDED LONG PERIODS OF RAIN. SINCE THIS WILL DEPEND
ON THE FINAL TRACK OF THE POTENTIAL LOW...WILL KEEP POPS IN THE
40-50 PERCENT RANGE FOR NOW. IF THE LOW DEVELOPS AND TRACKS TO OUR
WEST...A MORE FAVORABLE SCENARIO FOR SIGNIFICANT RAINFALL WILL
ESTABLISH AS S/SE FLOW NORMALLY BRINGS DEEP-LAYER MOISTURE INTO
THE SOUTHERN HALF OF THE STATE. STAY TUNED.

http://forecast.weather.gov/product.php ... glossary=1

Tallahhassee AFD

.LONG TERM (MONDAY THROUGH FRIDAY)...UPPER RIDGE AXIS OFF THE ERN
SEABOARD WILL BE REPLACED BY A RATHER SIGNIFICANT TROUGH EARLY IN
THE PERIOD. THIS WILL PUSH A SURFACE COLD FRONT SEWD THROUGH THE CWA
SUNDAY NIGHT...STALLING OVER THE CNTRL FL PENINSULA MONDAY NIGHT AND
TUESDAY. THEN THE FCST BECOMES COMPLICATED WITH THE GFS` DEVELOPMENT
OF A CUTOFF UPPER LOW INVOF SRN FL/FL STRAITS DURING THE TUESDAY
NIGHT/WEDNESDAY PERIOD. THIS SYSTEM HAS THE POTENTIAL FOR
SUB-TROPICAL DEVELOPMENT AS IT TRACKS WWD INTO THE ERN GOMEX
WEDNESDAY NIGHT AND THURSDAY...THEN NWWD TOWARD THE CNTRL GULF COAST
BY FRIDAY. OBVIOUSLY THIS SCENARIO WOULD KEEP CONDITIONS UNSETTLED
WITH A DEEP MOIST SELY FLOW. CONVERSELY...THE 12Z RUN OF THE ECMWF
GENERATED THE CUTOFF LOW E OF FL...WITH THE SYSTEM MEANDERING N OF
THE BAHAMAS. THIS SCENARIO WOULD GENERATE A DRIER NELY FLOW INTO THE
CWA. DUE TO THE LOW CONFIDENCE BEYOND DAY 4...IT SEEMS PRUDENT TO
LEAN CLOSER TO CLIMATOLOGY WITH REGARDS TO POP AND TEMPS. WINDS WILL
BE DEPENDENT ON THE FUTURE DEVELOPMENT/TRACK OF THE SURFACE LOW. FOR
NOW...WILL LEAN CLOSER TO THE ECMWF SOLUTION.

http://www.srh.noaa.gov/productview.php ... TAE&max=61

[ronjon]

From HPC this afternoon:

TODAY WE ARE MORE CONFIDENT THAT THERE WILL BE ENOUGH RIDGE ALOFT OVER THE SERN STATES TO RETARD THE NWD SPREAD OF SUBTROPICAL MOISTURE OFF THE GEORGIA AND CAROLINA COASTS NEXT WEEK. 12Z/15
MODEL CONSENSUS AND ENSEMBLES STILL SHOWS CYCLONIC VORTICITY ALOFT DEVELOPING SOMEWHERE SW OF FL BY WED DAY 5. THIS IS STILL IN A FAVORABLE POSITION TO EXCITE CONSIDERABLE SHRA/TSRA OVER THE FL
PENINSULA THE LATTER HALF OF THE MEDIUM RANGE. ANY SURFACE LOW THAT DEVELOPS IN RESPONSE TO THE UPPER VORTICITY WILL BE MONITORED FOR TROPICAL CHARACTERISTICS AS IT DRIFTS WWD INTO THE GULF OF
MEXICO THE LATTER PART OF NEXT WEEK.

[Tampa Bay Hurricane]

So the potential tropical low is a
second low, not the current Upper Level Low over Cuba?

[gatorcane]

Ed, what makes you think that is subtropical? Looks very tropical to me.

Day 9 850 mb winds, which I'd assume are similar to surface winds, not concentrated near lowest pressure

OK I see what you mean, NOLA AFD agrees with you:

LONG TERM...
COLD FRONT PASSES AND WE WILL SEE TEMPS FALL BACK A LITTLE WHICH
WILL BE NICE FOR THIS TIME OF YEAR. THIS OCCURS MONDAY THROUGH
WED. THURSDAY IS ANOTHER STORY. A VIGOROUS BAROCLINIC MID/UPPER
CUT OFF LOW FORMS FROM THE VERY TROUGH THAT ACCOMPANIES THE COLD
FRONT THROUGH THE AREA. A REFLECTIVE SFC LOW FORMS FROM THE
STACKED LOW AND BEGINS TO MOVE BACK TO THE NW. MODELS ARE
INDICATING THAT THE SFC LOW IS MOSTLY BAROCLINIC ATTM. ONE WAY OF
FINDING THIS OUT EASILY IS LOOKING AT THE WIND STRUCTURE AROUND
THE SYSTEM. WIND SPEEDS WEAKEN AS ONE MOVES TOWARD THE CENTER OF
THE CIRCULATION AND STRENGTHEN WELL AWAY FROM THE CENTER. NEEDLESS
TO SAY...WE SHOULD SEE WIND SPEEDS AND RAIN CHANCES INCREASE
TOWARD THE END OF THE WEEK ONCE AGAIN

http://www.srh.noaa.gov/lix/cgi-bin/get ... n=1&max=11

[Ed Mahmoud]

Ed, a 1000mb low pressure as indicated by the euro in its 240h forecast is not depression. Is a moderate strength tropical or subtropical storm. Not to say that it will pan out.

Although the Euro has the best grid scale resolution of any of the globals, they don't make too much available for free. And the display resolution is weak.


I can look at the GFS Hour 180, and see 250 mb winds and heights, and know a weakening upper low is over the forecast system, thus it isn't fully tropical.



I think our pro-met friends can see much more detailed Euro, at smaller than 24 hour time steps, and make a better answer.


Anyhoo, as we saw w/ the warm core, maybe, maybe not frontal Carolina storm of last year, there seems to be enough slack in the definition of tropical and sub-tropical storms that this system, even with gales over the Gulf, may or may not be designated by NHC.

[gatorcane]

Low along the Western tip of Cuba now depicted by TAFB in 72 hours:

[tina25]

I'm pretty much a lurker here but I wanted to jump in and point out.. for what it's worth, the Farmer's Almanac long-range forecast predicts that a tropical storm may threaten Florida towards the end of May. I found that kind of interesting.

http://www.almanac.com/weatherforecast/us/5

[cycloneye]

Ramsdis has a floater over the NW Caribbean,Western Atlantic,EGOM.

[Rainband]

let the games begin

[Ivanhater]

Gulf temps as of May 13

[gatorcane]

plenty warm enough to support a hurricane if the wind shear and other env. conditions are favorable which they are likely not going to be.

and by late next week they will be a few degrees warmer

Here is the Reynold's SST analysis, plenty warm enough in the GOM:

[Bailey1777]

TAFB posted by Gator is spot on with where GFS has potential low in 72hrs. Of course maybe that's what they use when they make that graphic, I don't know.

[Stormcenter]

A hurricane in the GOM in May? I really have to see that to believe it.

[srainhoutx]

Key West AFD snipet...not impressed...

.LONG TERM (SUNDAY THROUGH FRIDAY)...
A WEAK SURFACE LOW DEVELOPS IN THE GFS AND ECMWF LATE MONDAY KEEPING
THE SERVICE AREA IN A MORE SOUTHERLY FLOW THROUGH THE END OF THE
WEEK. THE MAIN DIFFERENCE BETWEEN THE TWO FAVORED MODELS IS THAT THE
ECMWF WILL COVER A BROADER AREA HENCE HAVE A WEAKER PRESSURE
GRADIENT. HAVE GONE WITH THE GFS WIND FIELDS THROUGH THE END OF THE
WEEK BUT MAY HAVE TO ADJUST THE WINDS FOR LATER PERIODS. THE MID
RANGE UNCERTAINTY STILL EXISTS IN THE MODELS AT THIS TIME. I EXPECT
TO SEE MORE CONSISTENT RUN TO RUN PARITY BEFORE GIVING INTO THE MID
RANGE COMPLETELY.

http://www.srh.noaa.gov/productview.php ... KEY&max=51