Post Tropical Cyclone Debby

[PSUBlizzicane2007]

I agree with your series of events, I just think the time frame will be longer. At least in the WPAC when dealing with monsoon depression-type disturbances, it takes a lot of latent heat release to reorganize the mass field and get the main LLC to tighten underneath the deepest convection. Granted, there is no convection over the current LLC right now, which may help, but I'm skeptical that this will be a process that takes <36 hours.

Right I've always been at roughly 36 hours for this type of stuff...assuming a good environment in which 96L is located. If the convection pulsates too much again, it may take even longer.

[Srain]

It don't see any development if any before Monday. The approaching trough across the Southern Plains does appear to be a bit ahead of schedule and 96L likely will remain an elongated broad circulation extending from the Bay of Campeche on NE to near Apalachicola Bay with several mid/upper vorts spinning E along the trough axis. Once the trough passes and the Central US Ridge builds, then I believe conditions may become a bit more conducive for development in Central Gulf. My hunch is we will be talking about this feature/slopgyre well into next week. Enjoy your vacation, Adam.

[turtlehurricane]

The measurements from this buoy are intriguing. http://www.ndbc.noaa.gov/show_plot.php?station=42056&meas=wdpr&uom=E&time_diff=-5&time_label=CDT

Looking better than yesterday, but it is a fairly similar situation.

[wxmx]

I disagree with the center relocation. The low is just simply huge, and it would take strong/unabated convection for a long time over the mid level energy to overhelm the broad low and form it's own, dominant low level low. Most global models keep the current low as the one that eventually develops.

[PSUBlizzicane2007]

I disagree with the center relocation. The low is just simply huge, and it would take strong/unabated convection for a long time over the mid level energy to overhelm the broad low and form it's own, dominant low level low. Most global models keep the current low as the one that eventually develops.

The reason for that is that they see the current low as the only one. Models aren't great predictors of reforming low level centres over short time frames.

[turtlehurricane]

Cloud tops on a warming trend today, I get the feeling it's going to fizzle just like yesterday. Classic pulsating blob.

[wxmx]

The reason for that is that they see the current low as the only one. Models aren't great predictors of reforming low level centres over short time frames.

Still, the previous reasoning stands. There's a huge closed low that covers most of the GOM, it's not going to fade away in a short period of time...also, the MLC's related convection is of a pulsing nature, and pressures are not lowering over there.

Only way I could see another low forming, is that a piece of energy splits away from the main low (GFS solution).

[Srain]

FWIW...the 12Z Canadian is W for the 5th cycle.

[wxmx]

12z CMC has landfall around Port LaVaca and 12z UKmet around Corpus...12z GFS gets a weak low hooked by the eastern trough.

[Scott747]

12z CMC has landfall around Port LaVaca and 12z UKmet around Corpus...12z GFS gets a weak low hooked by the eastern trough.

I'm going with Sargent Beach.

Sure is consistent so far....

[HurricaneJosh]

I'm going with Sargent Beach.

C'mon.

[DaculaWeather]

Key West Dual Pol Loops

http://www.daculaweather.com/grlevel4/4_any_br248.php

[Scott747]

C'mon.

I could go full homer and say Freeport/Surfside Beach, Texas.

Stay calm over there. 40 kt system isn't even worth a walk to the beach. Well, maybe a quick one.

[HurricaneJosh]

I could go full homer and say Freeport/Surfside Beach, Texas.

Stay calm over there. 40 kt system isn't even worth a walk to the beach. Well, maybe a quick one.

Dude, I'm sweatin' bullets over this one. And I ain't jokin'.

[Scott747]

12z HWRF takes borderline TS into Big Bend area.

[Mencken_Fan]

The USA hasn't had a June hurricane landfall since 1986-- so it's climatologically very unusual.

June landfalls in the USA since 1950:

1986 - Bonnie - TX

1972 - Agnes - FL (NW)

1966 - Alma - FL (NW)

1957 - Audrey - LA/TX

As you can see, all of them were on the Gulf Coast, and none of them were majors.

Re: Audrey... Yes, it's officially a Cat 4, but it hasn't been reanalyzed yet. Contemporary analysis done by reputable researchers (like Brian Jarvinen) suggests it was much, much weaker-- maybe even a strong Cat 1. Let's see what the Best Track Committee says. My guess is they compromise and settle on Cat 2 (like 85 or 90 kt).

Agnes...rain, rain, and more rain; a classic example of the potential inland damage from tropical cyclones. The Potomac River at Great Falls (just north of D.C.) rose 50 feet, destroying the Maryland side overlook and all the steel re-enforced concrete, gorge-crossing bridges leading to it. The C&O Canal was much obliterated.

Unfortunately it took 20 years for the National Park Service to restore this wonderful park area, a gorgeous respite from the city, and just a few miles from where I grew up.

Great Falls, Montgomery County, Maryland:

http://glenecho-cabinjohn.com/GF-01.html

Agnes killed 128 people; 19 of them in Maryland.

[turtlehurricane]

I talked about some of the the dynamics associated with pulsating tropical disturbances on my blog, along with an overall analysis/forecast of 96L. http://weather.schematical.com/

Rain from the disturbance is already overspreading South Florida, NWS saying 2-6" possible with more towards the west coast. Should increase as the disturbance drifts north.

[jrips27]

Looks like the 12z Euro is going to TX/MX border.

[wxmx]

Looks like the 12z Euro is going to TX/MX border.

Right smack in the border.

[HurricaneJosh]

Right smack in the border.

Beulah.

[tmagan]

18Z Observations

[PSUBlizzicane2007]

Beulah.

(Lite™)

[Minnesota Meso]

GFS ensembles are now over sw TX.

[Srain]

HPC through the Euro cycle:

MONSOON DEPRESSION IN THE GULF OF MEXICO...

PREFERENCE: 12Z GEFS MEAN/06Z HWRF COMPROMISE

CONFIDENCE: ABOVE AVERAGE FOR TRACK SHAPE/BELOW AVERAGE FOR

PROGRESSION/SPEED

THE 12Z GFS CONTINUES TO DRAG THIS CYCLONE TOWARDS TAMPA /THOUGH

SLOWER THAN ITS 06Z RUN/...USING A PAIR OF CONVECTIVE FEEDBACK

BULL'S EYES/QPF BOMBS TO LURE ITS CENTER NORTHEASTWARD...IMPLYING

SOUTHWESTERLY VERTICAL WIND SHEAR. IT HAS BEEN PERSISTENT IN

SHOWING THIS TYPE OF SOLUTION FOR AT LEAST THREE DAYS NOW. THE

GENERAL FLOW PATTERN FEATURES A BUILDING WARM CORE RIDGE ACROSS

CENTRAL PLAINS WITH A SECOND WEAKER RIDGE NORTH OF THE GREATER

ANTILLES...AND A NEGATIVELY TILTED UPPER TROUGH EXTENDING FROM THE

EAST COAST INTO THE WESTERN ATLANTIC WITH A SLIGHT BREAK AT

500/700 HPA ACROSS THE SOUTHEAST. THE GUIDANCE CONTINUES TO

INDICATE THAT THE COL POINT IN THE STEERING PATTERN IS NEAR

NORTHERN FLORIDA/SOUTHERN GEORGIA...WHICH WOULD FORCE A SYSTEM IN

THE GULF TO STEER INITIALLY NORTH AND ULTIMATELY WEST UNDER THE

PLAINS RIDGE DURING THE LATE SHORT RANGE/MEDIUM RANGE PERIOD.

THERE IS ABOVE AVERAGE CONFIDENCE IN THIS IDEA.

HOWEVER...ONCE THE RIDGE BUILDS...THE LOW COULD EASILY ACCELERATE

WEST/WEST-SOUTHWEST BEGINNING ON SUNDAY SIMILAR TO CLAUDETTE IN

2003 /AND AS ADVERTISED IN THE NON-GFS 12Z GUIDANCE/. THE 12Z

GUIDANCE HAS ALL TRENDED MORE WESTWARD LATE MONDAY SINCE THEIR

PRIOR RUNS. THE ONLY OTHER ANALOGS TO THIS TYPE OF TROPICAL

CYCLONE-TYPE TRACK WERE IN OCTOBER 1938 AND JUNE 1913. THE GLOBAL

ENSEMBLE SPREAD CONTINUES TO WAVER EACH DAY...WITH ABOVE AVERAGE

SPREAD SEEN TODAY AND WEDNESDAY WHILE LOWER THAN NORMAL SPREAD WAS

SEEN TUESDAY AND THURSDAY. WHEN THE ENSEMBLE GUIDANCE SHOWS SUCH

VARIABILITY...IT IS UNCLEAR HOW/WHEN TO START ITS WESTWARD

PROGRESSION. THE HURRICANE GUIDANCE BASED ON THE 06Z GFS

/INCLUDING THE 12Z WRF/ MIRRORS THE 06Z GFS...WHICH INCREASES THE

APPARENT MODEL SPREAD WITH THIS SYSTEM. THE PREFERENCE IS FOR A

12Z GEFS MEAN/06Z HWRF COMPROMISE TO SPLIT THE DIFFERENCE IN THE

LARGE SPREAD WITH BELOW AVERAGE CONFIDENCE IN ITS ULTIMATE

WESTWARD PROGRESSION/SPEED. THIS KEEPS GOOD CONTINUITY WITH

MEDIUM RANGE AND NHCS 17Z THINKING. CONSULT THE LATEST TROPICAL

WEATHER OUTLOOK FROM THE NATIONAL HURRICANE CENTER /NHC/ FOR ITS

CURRENT STATUS.

[Superstorm93]

Nice dramatic collapse

[PSUBlizzicane2007]

Nice dramatic collapse

Yup. Clearly this is never going to develop.

[Brent]

Nice dramatic collapse

Season cancel

[HurricaneJosh]

(Lite™)

Zero-Calorie Beulah. All the cyclone-- without the wind.™

[PSUBlizzicane2007]

Zero-Calorie Beulah. All the cyclone-- without the wind.™

Wouldn't a Don technically qualify as Zero-Calorie?

[Srain]

The chatter has increased mainly due to Marine issues after a Conference Call with various NWS and NHC officials:

New Orleans:

.MARINE...

AFTER A COASTAL OFFICE COORDINATION/COLLABORATION CALL FROM KBRO-

KTPA INCLUDING THE TAFB UNIT AND SR ROC...WFO CONCENSUS WAS TO

FOLLOW NHC/HPC COORDINATED LOW PRESSURE POSITIONS THROUGH DAY 5.

UNFORTUNATELY NOT MANY OF THE CONVENTIONAL MODELS DEPICTED A WIND

FIELD SIMILARLY EXCEPT THE NAM12 IN THE SHORT TERM. THE NAM WAS

USED TO INITIATE WIND FIELDS THROUGH DAY3...THEN BLENDING TOWARDS

ECMWF WIND FIELDS THEREAFTER. GULF WAVES WERE THEN GENERATED USING

A WIND/WAVE CONVERSION THEN APPLYING A NEAR COASTAL WAVE TOOL FOR

SHALLOW WAVE AREAS. THIS PRODUCED A MORE BELIEVABLE WIND/WAVE

COMBINATION WHEN COMPARED TO THE WAVEWATCH SOLELY DRIVEN OFF THE

GFS SOLUTION. EASTERLY WINDS SHOULD INCREASE STEADILY TO 20-25 KTS

DURING THE DAY SATURDAY WITH GUSTS APPROACHING 45 KTS AT TIMES

SUNDAY...PARTICULARLY IN THE OUTER COASTAL WATERS. A SLOW

IMPROVEMENT WILL BE INDICATED FOR EARLY NEXT WEEK ASSUMING A

WESTWARD DRIFT OF THE SYSTEM AS INDICATED ABOVE. THIS IS SUBJECT

TO CHANGE IF THE SYSTEM SHOULD REMAIN ON A MORE NORTHWARD TRACK

FOR LONGER THAN CURRENTLY INDICATED. SEAS ARE INDICATED TO

INCREASE TO 10-13 FEET IN TIME AS THE WINDS INCREASE SUNDAY.

Lake Charles:

THE REAL CHALLENGE AT THIS POINT DURING THE FORECAST IS WHAT TO DO

ABOUT THE LOW PRESSURE SYSTEM NEAR THE YUCATAN PENINSULA. NHC IS

STILL GOING WITH A 70 PERCENT CHANCE SO IT IS LIKELY TO FORM PER

THEIR FORECAST. THEREFORE APPROACHED THE FORECAST ASSUMING IT WILL

FORM AND COLLABORATED WITH SURROUNDING OFFICES CONCERNING WINDS AND

WAVES. MOST OF THE GUIDANCE MODELS ALL AGREE ON NORTHWARD MOVEMENT

TOWARDS THE BIG BEND REGION OF FLORIDA THROUGH SUNDAY AROUND 00Z.

THEN THE GFS TAKES THE SYSTEM EASTWARD ACROSS FLORIDA AND INTO THE

ATLANTIC. ALL OF THE OTHER GLOBAL MODELS DRIFT THE SYSTEM BACK TO

THE WEST AND GIVEN THAT... WENT WITH A COMPROMISE OF THAT SOLUTION.

ONE VERY INTERESTING VERSION IS THE CANADIAN MODEL WHICH DEVELOPS AN

INTENSE TROPICAL CYCLONE AND AS OF THE LATEST MODEL RUN IT HAS THE

STORM MAKING LANDFALL IN THE TEXAS COAST ALBEIT IS WAY TO EARLY TO

MAKE JUDGMENTS BASED ON JUST ONE MODEL GIVEN THAT NHC HAS YET TO

NAME THE SYSTEM. WINDS AND WAVE HEIGHTS WILL PICK UP ESPECIALLY OVER

THE COASTAL WATERS BEGINNING MONDAY AS THIS STORM BEGINS TO MOVE

TOWARDS THE WEST. RIGHT NOW HAVE SMALL CRAFT EXERCISE CAUTION

THROUGH TOMORROW AT 00Z BUT THAT WILL HAVE TO BE EXAMINED FOR A

POTENTIAL SMALL CRAFT ADVISORY AS WINDS AND WAVES BEGIN TO INCREASE.

WILL CONTINUE TO MONITOR AND COLLABORATE WITH SURROUNDING WFOS AND

NHC REGARDING THIS SYSTEM AND FURTHER DEVELOPMENT.NEED TO STRESS

THAT THIS SYSTEM HAS NOT YET BEEN NAMED NOR HAVE ANY ADVISORIES BEEN

ISSUED THEREFORE MUCH OF THE GULF COAST SHOULD MONITOR PRODUCTS AND

INFORMATION COMING FROM NHC REGARDING ANY AND ALL FUTURE DEVELOPMENT

WITH THIS SYSTEM.

THE OTHER FORECAST CHALLENGE THAT IS IMPORTANT FOR THE AREA IS THE

IMPENDING HEAT WAVE. BOTH THE ECMWF AND THE SREF ARE SHOWING QUITE A

BIT OF HEAT TO MOVE IN DURING THE SUN MON TUES TIME FRAME. WITH THE

HIGH PRESSURE SITTING DIRECTLY ON TOP OF THE REGION EXPECT TEMPS TO

JUMP UP TO TOUCHING THE TRIPLE DIGITS PLATEAU ESPECIALLY TOWARDS THE

NORTHERN PORTION OF THE CWA. THIS WILL BE CAUSE FOR CONCERN FOR THE

AREA BECAUSE MODELS ARE FORECASTING THERE TO BE ENOUGH MOISTURE IN

THE LOW LEVELS TO KEEP DEW POINTS IN THE 70S. WITH TEMPS

APPROACHING TRIPLE DIGITS AND DEW POINTS THAT HIGH WE COULD BE IN

FOR A HEAT ADVISORY WITH APPARENT TEMPS APPROACHING THE CRITERIA OF

ABOVE 107. WILL NEED TO WAIT FOR BETTER CONSISTENCY WITH FORECASTED

MODELED TEMPS BUT EITHER WAY EXPECT THE BEGINNING OF NEXT WEEK TO BE

HOT AND APPROPRIATE SAFETY GUIDELINES NEED TO BE FOLLOWED.

WITH THE HIGH PRESSURE DOMINANT EXPECT TO BE MOSTLY PRECIP FREE. IF

THE LOW PRESSURE SYSTEM MOVES INTO THE AREA...AND MOST OF THE

GUIDANCE SUGGEST AS OF THE LATEST MODEL RUNS IT WILL PASS TO THE

SOUTH... THEN EXPECT THERE TO BE A BOOST IN POP DURING THE MIDDLE OF

NEXT WEEK.

&&

.MARINE...

HIGH PRESSURE FROM OFF THE ATLANTIC WILL MAINTAIN EASTERLY TO

NORTHEASTERLY FLOW OVER THE COASTAL WATERS THROUGH THE WEEKEND.

AN AREA OF DISTURBED WEATHER ASSOCIATED WITH A BROAD AREA OF LOW

PRESSURE OVER THE SOUTHERN GULF OF MEXICO COULD POTENTIALLY ORGANIZE

AND BEGIN DRIFTING NORTHWARD OVER THE WEEKEND...THEN EVENTUALLY

TURN TO THE WEST AND CROSS THE NORTHERN GULF DURING THE COMING

WEEK. THIS SOLUTION WOULD LEAD TO INCREASING WINDS AND WAVE HEIGHTS

REACHING AT LEAST SMALL CRAFT ADVISORY CRITERIA...SEAS AND TIDES

FOR THE COASTAL WATERS WILL BE ELEVATED IF THIS FORECASTED SOLUTION

IS CORRECT..THEREFORE MARINE INTERESTS SHOULD MONITOR PRODUCTS ISSUED

BY THE NATIONAL HURRICANE CENTER FOR FURTHER INFORMATION AND DETAILS

ON ANY POTENTIAL TROPICAL DEVELOPMENT.

Houston/Galveston:

.MARINE...

TIDE LEVELS ARE STILL RUNNING 1-1.5 FEET ABOVE NORMAL AND WILL BE

MONITORED FOR THE NEXT SEVERAL DAYS AND INTO NEXT WEEK WITH A

CONTINUED LONG FETCH OF MODERATE ENE WINDS ACROSS THE NRN GULF.

NOT EXPECTING MANY SIGNIFICANT CHANGES OVER THE WEEKEND THAT WOULD

CAUSE MAJOR CHANGES TO THE LEVELS. ASTRONOMICAL HIGH TIDES ALONG

THE BEACHES SHOULD BE RUNNING 1.8-2.0 FEET. SO WE`LL BE JUST BELOW

THE TOTAL 3.7 FEET CRITERIA (ASTRONOMICAL + METEOROLOGICAL) WHEN

WE TYPICALLY SEE SOME MINOR COASTAL FLOOD ISSUES AT THE LOWEST

LOCATIONS. MAY NEED A COASTAL FLOOD WATCH EARLY NEXT WEEK

DEPENDING ON WHAT EVENTUALLY EVOLVES IN THE GULF.

LARGE ELONGATED...AND POORLY ORGANIZED...DISTURBANCE EXTENDING

FROM THE CNTL GULF SOUTHWARD INTO THE YUCATAN AND CARIBBEAN STILL

EXPECTED TO DRIFT NWD OVER THE WEEKEND (MAYBE POSITIONED A COUPLE

OF HUNDRED MILES SOUTH OF LA SUNDAY). SLOW DEVELOPMENT IS

POSSIBLE...BUT THAT AND EVENTUAL TRACK IS STILL UNCLEAR AND

PROBABLY REMAIN THAT WAY UNTIL A GOOD LLVL CIRCULATION IS

IDENTIFIED. SPECIAL THANKS TO NWS SLIDELL WHO ORGANIZED A

CONFERENCE CALL WITH GULF COAST OFFICES AND TAFB TO COORDINATE THE

OVERALL MARINE FCST. WE WILL GENERALLY TREND WITH AN EVENTUAL WWD

TRACK DURING THE EARLY AND MID WEEK PERIODS WHICH WILL INCREASE

WINDS/SEAS OFFSHORE - WHICH RUNS COUNTER TO THE WAVEWATCH III

GUIDANCE (WHICH TAKES THE SYSTEM EWD). WE UNDERSTAND A LOT OF

FOLKS SEE AND USE THIS MODEL ONLINE AND USE AS GUIDANCE SO BE

ADVISED...AND EXPECT SEVERAL CHANGES IN THE FCST BETWEEN NOW AND

MID-LATE NEXT WEEK.

Corpus Christi:

LONG TERM (SUNDAY THROUGH FRIDAY)...OBVIOUSLY MOST OF THIS FCST PD

WL DEPEND LARGELY UPON THE EVENTUAL TRACK OF WHAT WL LKLY BECOME THE

FOURTH-NAMED STORM OF THE SEASON ORIGINATING FROM THE SOUTHERN

GULF. THERE REMAINS TWO DISTINCT POSSIBLE TRACKS AS OUTLINED BY THE

GUIDANCE THE PAST FEW DAYS. THE GFS SOLN IS STILL HOLDING ON TO A

MORE NORTHEASTERLY TRACK WHICH WOULD AFFECT FLORIDA. HOWEVER WITH

MOST OF THE GLOBAL MODELS (ECMWF...CANADIAN...NAM...UKMET...NOGAPS)

NOW INDICATING A MORE WESTERLY TRACK WITH THIS SYSTEM...IT WAS TIME

TO NUDGE THE FCST IN THIS DIRECTION. ALSO THIS WL BETTER MATCH UP

WITH NHC/HPC/TAFB/SURROUNDING WFOS AS WELL. SO DECIDED TO BUMP UP

THE SEAS AND WINDS THROUGH MIDWEEK. FOR NOW...WL ONLY GO AS HIGH AS

8 FT SEAS ARRIVING BY WED WITH A GRADUAL INCREASE BETWEEN SUN AND

TUE AS THE SYSTEM APPROACHES FROM THE EAST. WL BE MORE TEMPERED ON

THE WIND FCST GIVEN THAT THESE ARE DAYS 4-6 OF THE FCST AND DUE TO

LARGE TRACK UNCERTAINTY EVEN WITH THESE WESTERLY-SHIFTING GLOBAL

MODELS. WITH TIDES ALREADY RUNNING JUST OVER 1 FT ABV PREDICTED

LVLS AND DUE TO INCOMING LARGE SWELLS...MINOR COASTAL FLOODING AND

HIGH SURF WL LKLY BE AN ISSUE BEGINNING BY SUN AND MON. TOO EARLY

AND NOT VERY CONFIDENT AT GOING WITH TOO HIGH OF A POP FOR THE

LATTER PART OF THE FCST. WL PUNT AND MAINTAIN JUST SLIGHT CHC POPS

BUT THESE MAY NEED TO BE SIGNIFICANTLY INCREASED BY LATER SHIFTS. A

SUBSIDENT AND DRY SYNOPTIC PATTERN WL PREVAIL EITHER WAY THROUGH THE

FIRST PART OF THE FCST AS A STRONG MID/UPR RDG AXIS REMAINS ANCHORED

ACROSS THE SRN PLAINS. WL KEEP HIGHS ON THE WARM SIDE OF GUIDANCE

THROUGH AT LEAST TUE GIVEN THIS PATTERN.