ATL: EX-Tropical Depression FIVE - Discussion

[cycloneye]

60% Code Red

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT MON AUG 16 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

AN AREA OF LOW PRESSURE...THE REMNANT OF TROPICAL DEPRESSION
FIVE...IS LOCATED OVER THE NORTHEASTERN GULF OF MEXICO ABOUT 60
MILES SOUTHWEST OF PANAMA CITY FLORIDA. ENVIRONMENTAL CONDITIONS
ARE FORECAST TO BE CONDUCIVE FOR SOME DEVELOPMENT OF THIS SYSTEM AS
IT MOVES GENERALLY WESTWARD AND THEN WEST-NORTHWESTWARD OVER THE
NORTHERN GULF OF MEXICO DURING THE NEXT DAY OR SO. THERE IS A HIGH
CHANCE...60 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
AGAIN DURING THE NEXT 48 HOURS. REGARDLESS OF DEVELOPMENT...
LOCALLY HEAVY RAINFALL AND GUSTY WINDS ARE POSSIBLE ALONG PORTIONS
OF THE NORTH CENTRAL GULF OF MEXICO COAST THROUGH TUESDAY. SEE
STATEMENTS FROM LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICES FOR
ADDITIONAL INFORMATION.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER KIMBERLAIN/PASCH

[Aric Dunn]

Not much in the way of divergence aloft currently.

love the equation you have by the way ...... well the cimss map does not seem to showing much at the moment but there should be plenty of upper support to see this become a TD

[cycloneye]

12z Best Track

AL, 05, 2010081612, , BEST, 0, 294N, 861W, 20, 1009, LO

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

[Aric Dunn]

Still no tight LLC ... broad is still the name of the game..

[srainhoutx]

Also the Best track is a bit further S and W.

[Aric Dunn]

Also the Best track is a bit further S and W.

my position last night 3am ...

Pressures are starting to fall now ( about 1 MB in the last hour) and convection is becoming better organized. aprox center of developing LLC is 29.3N 86.2W.. accept a system nearing TD status but 11am ... if all goes well ...

its been nearly stationary for the last 6 hours..

12z Best Track

AL, 05, 2010081612, , BEST, 0, 294N, 861W, 20, 1009, LO

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

[Aric Dunn]

well It seems the position of the upper high is just not in the right spot and is imparting too much shear... could still make it to TD but TS is looking less likely..

[Stormcenter]

I believe conditions may improve and leave a window of opportunity for strenghthening
to a TS before landfall. IMO

well It seems the position of the upper high is just not in the right spot and is imparting too much shear... could still make it to TD but TS is looking less likely..

[bayoubebe]

Good read from the NWS out of New Orleans.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
527 AM CDT MON AUG 16 2010

.SYNOPSIS...
SURFACE ANALYSIS SHOWS A BROAD AREA OF 1010 MB LOW PRESSURE OVER
THE EXTREME NORTHERN GULF OF MEXICO SOUTH OF THE WESTERN FLORIDA
PANHANDLE. SUSTAINED WINDS APPEARED TO BE AVERAGING AROUND 15
KNOTS WITH SOME HIGHER GUSTS OBSERVED IN AND NEAR CONVECTION ON
THE SOUTHWEST SIDE OF THE LOW. SHOWER AND THUNDERSTORM ACTIVITY
HAS BEEN VERY DISORGANIZED NEAR THE CENTER OF THE LOW...BUT
APPEARED TO BE SLOWLY INCREASING THE LAST HOUR OR TWO.

A BROAD CYCLONE EXTENDS FROM THE SURFACE UP TO AROUND 500
MB...THEN THERE IS ABOUT 20 TO 30 KNOTS OF NORTHEAST SHEAR IN THE
UPPER LEVELS AROUND 300-200 MB. LOOKING AT SATELLITE...ESPECIALLY
WATER VAPOR LOOPS...ALL THE UPPER LEVEL FEATURES FROM THE BAJA
MEXICO AREA TO THE NORTHERN GULF COAST ARE MOVING WEST IN THE WEAK
TROPICAL EASTERLIES.

&&

.SHORT TERM...
THE EAST TO WEST STEERING CURRENTS DESCRIBED IN THE SYNOPSIS
SECTION ARE LIKELY TO NUDGE THE SURFACE LOW WEST FROM SOUTH OF THE
FLORIDA PANHANDLE TOWARDS THE SOUTHEAST LOUISIANA COAST LATE
TONIGHT AND EARLY TUESDAY MORNING. THE LARGER SCALE...CONVENTIONAL
MODELS ALONG WITH AND TROPICAL CYCLONE MODEL TRACK GUIDANCE ARE IN
PRETTY GOOD AGREEMENT AND FIT THE OVERALL PATTERN VERY WELL. OF
COURSE...THE BIGGER PROBLEM AS ALWAYS IS INTENSITY...AND THIS HAS
BEEN A PROBLEM ALL YEAR WITH WEAKER TROPICAL LOWS AND DEPRESSIONS.
THE RUC MODEL APPEARS TO HANDLE THE 250 MB WIND FIELD BETTER
ACROSS THE LOW PRESSURE AREA AROUND 12Z THIS MORNING...SHOWING
VALUES CLOSER TO REALITY AT 15 TO 20 KNOTS VERSUS THE NAM AND GFS
WHICH ONLY SHOW 5 TO 10 KNOTS. EVENTUALLY...THE LOW PRESSURE AREA
WILL COME UNDER LESS NORTHEASTERLY SHEAR IN THE UPPER LEVELS AS IT
MOVES CLOSER TO THE UPPER HIGH TO THE NORTHWEST.

GIVEN THE CURRENT OBSERVATIONS AND RADAR PRESENTATION...I AM NOT
EXPECTING RAPID DEVELOPMENT OF THE LOW INTO A TROPICAL
CYCLONE...BUT THAT COULD HAPPEN LATER TODAY OR TONIGHT IF
DEEPER...MORE SUSTAINED AND CONCENTRATED CONVECTION DEVELOPS NEAR
THE LOW CENTER.

REGARDLESS OF THE AMOUNT OF DEVELOPMENT...THE SCENARIO REMAINS THE
SAME WITH REGARDS TO THE MAJOR THREAT WHICH WILL BE HEAVY RAIN AND
FLOODING. THE SLOW MOVEMENT OF THE SYSTEM WILL LIKELY PRODUCE A
FAIRLY LARGE AREA OF 3 TO 5 INCHES OF RAINFALL WITH LOCALIZED
AMOUNTS AROUND 8 INCHES POSSIBLE...ESPECIALLY NEAR THE SOUTHEAST
LOUISIANA COAST. NOTE...IF THIS LOW TAKES ON MORE TROPICAL
CHARACTERISTICS AND MOVES A BIT SLOWER THAN EXPECTED...THESE
FORECAST RAINFALL AMOUNTS MAY HAVE TO BE INCREASED BY SEVERAL
INCHES.

A possibility of 8 inches, that's alot around here, especially given some places just had flooding last week.

[srainhoutx]

Sunrise...

[StormClouds63]

from the Lake Charles NWS discussion Monday morning. The 50% chance for development discussed below is now 60% (high).

NATIONAL WEATHER SERVICE LAKE CHARLES LA
434 AM CDT MON AUG 16 2010

.SHORT TERM...

MAIN ISSUES IN THE SHORT TERM INVOLVE THE FUTURE OF WHAT WAS ONCE TROPICAL DEPRESSION 5. LATEST SURFACE AND BUOY OBS INDICATE THE REMNANT LOW PRESSURE OF TD5 HAS MOVED SOUTHWARD INTO THE NORTHERN GULF OF MEXICO JUST SOUTH OF PANAMA CITY. 00Z MODEL GUIDANCE CONTINUES TO SUGGEST THIS REMNANT LOW MAY REORGANIZE INTO A TROPICAL DEPRESSION LATER TODAY INTO TOMORROW AS IT TURNS WESTWARD TOWARDS THE SOUTHEAST LOUISIANA COAST...WITH NHC GIVING THE SYSTEM A 50 PERCENT CHANCE OF REDEVELOPMENT. LATEST 00Z MODEL GUIDANCE HAS TRENDED NORTHWARD BUT REMAINS VERY TIGHTLY CLUSTERED WITH THE TRACK OF THE LOW...TAKING THE SYSTEM INLAND ACROSS SOUTHEAST LOUISIANA ON TUESDAY...THEN TURNING IT MORE NORTHWESTWARD AS IT
MOVES ACROSS OUR FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY. SUCH A TRACK WILL GIVE FORMER TD5 LITTLE TIME TO REORGANIZE INTO A TROPICAL CYCLONE BEFORE MOVING BACK OVER LAND...AND ANY SIGNIFICANT STRENGTHENING SEEMS UNLIKELY AT THIS TIME.

HAVE GENERALLY SIDED WITH THE 00Z EMCWF IN DAY 1-3 TIMEFRAME AS IT SEEMS MORE REASONABLE IN ITS DEPICTION OF A WEAKER AREA OF LOW PRESSURE. THUS THE MAIN IMPACT FROM THIS SYSTEM WILL BE HEAVY RAINFALL AND THE POTENTIAL FOR FLOODING AS THE CENTER OF THE LOW SLOWLY MAKES ITS WAY ACROSS OUR CWA. LATEST HPC GUIDANCE INDICATES 3 DAY AREAL RAINFALL TOTALS FROM TODAY THROUGH WEDNESDAY OF 4 TO 7
INCHES ACROSS ACADIANA...WHICH WOULD CERTAINLY WARRANT A FLASH FLOOD WATCH. WITH THE BULK OF THE HEAVY RAINFALL NOT EXPECTED TO BEGIN UNTIL AFTER 12Z TUESDAY...WILL HOLD OFF ON ISSUING A WATCH THIS FAR OUT IN TIME BUT ONE WILL LIKELY BE NEEDED FOR THE LAFAYETTE/NEW IBERIA/MORGAN CITY REGION LATER TODAY. HAVE RAISED POPS AREAWIDE FOR TUESDAY AND WEDNESDAY WITH HIGHEST CHANCES IN SOUTHEAST ZONES.

[tigergirl]

I'm hoping that I get another rain free day to dry up before it heads west.

[N2Storms]

[quote="tigergirl"]I'm hoping that I get another rain free day to dry up before it heads west.[/quote]



It's very nice right now here in Panama City. Not much rain expected here at all. Whatever ex-TD5 becomes it is expected to a non-event here according to the TLH NWS. Just some scattered pop-up showers here and there today and tomorrow looks to be even better.

[StormClouds63]

Last several days the indication was that upper environmental conditions would be favorable for development ... but this morning, here comes mention of the old "shear monster" who has been king so far in this tropical season. Perhaps less shear as it moves south and then west?

[tailgater]

Still no tight LLC ... broad is still the name of the game..

Looks like it is starting to tighten up South of Destin. Not there just yet but definitely closing up tighter, which was and is one of the major reason this system hasn't really strengthened.IMHO

[Stormcenter]

I believe ex-TD5 is starting wrap up.

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html


http://www.rap.ucar.edu/weather/satelli ... uration=12

[LSU2001]

Well it does not appear that dry are will be any problem this time around. Shear may be but if the anti-cyclone moves over the disturbance or the disturbance moves under it we could see some fairly rapid intensification;
Tim

[TheBurn]

[Cyclone1]

That visible loop this morning looks promising.

[Aric Dunn]

Still no tight LLC ... broad is still the name of the game..

Looks like it is starting to tighten up South of Destin. Not there just yet but definitely closing up tighter, which was and is one of the major reason this system hasn't really strengthened.IMHO

its slowly getting there...but the shear is still a little too high atm ... will see what happens with the placement of high..