Frances Advisories

[Matthew5]

Over the last hour convection on the western Quad has started to break. The same dry area as was shown last night about the same spot is starting to show tonight. The inner eye should fall apart, with in the next 12 hours being replaced with a new 35 to 40 nmi wide eye. I'm going to forecast by later this morning into the afternoon, it should be done. In we should see a larger eye. By Tomarrow night it should be clear again. This will likely weaken below 130 mph with an the next 6 hours. Then become a 140 mph hurricane again by the 11pm Advisory Wednesday. A track off the the west to west-northwest should be expected over the next 24 to 36 hours. Reasoning behind that is the large area of high pressure that has built all the way into the eastern Gulf of mexico. Some of the models forecast a weakness over the next 72 hours to develop. This "might" turn it more to around west-northwest maybe even northwest. The comptuer models have shifted back to the west so there is a fair chance that the weakness/trough should stay farther to the west over the rockie mountains. While that means that this high will remain strong. The water temperatures rise into the mid to upper 80s around 75 west. The laten heat should be able to support cat5 hurricane around 75 west to. I forecast a eye wall replacement around every 24 to 36 hours. I also think this will become a short lived cat5. Landfall should be from Miami to Palm Beach Florida late Friday night into Saturday morning.


Forecast winds
Now 140 mph...939 millibars(1am pst/4am est Wednesday)
3....130 mph...944 millibars(4am pst/7am est)
6....125 mph...948 millibars(7am pst/10am est)
9....130 mph...943 millibars(10am pst/1pm est)
12...135 mph...939 millibars(1pm pst/4pm est)
18...145 mph...935 millibars(4pm pst/7pm est) Moving near warmer laten heated water...
24...150 mph...928 millibars(7pm pst/10pm est)
27...160 mph...924 millibars(10pm pst/1am est Thursday)
30...160 mph...924 millibars(1am pst/4am est)
33...160 mph...924 millibars(4am pst/7am est)
36...150 mph...931 millibars(7am pst/10am est) Eye wall replacement two.
39...135 mph...938 millibars(10am pst/1pm est)
42...130 mph...940 millibars(1pm pst/4pm est)
45....140 mph..932 millibars(4pm pst/7pm est)
48....150 mph..928 millibars(7pm pst/10pm est)

On Friday this might be another eyewall replacement around the 3 to 6pm est. It may come in as a strong cat4 later Friday into early Saturday.


Matthew

[calidoug]

There is really no scientific basis for making intensity predictions with that degree of precision of wind speeds, pressures, and timing.

[Matthew5]

I thought I would take a shot at it

[TampaFl]

NOt looking good.

FXUS62 KMLB 010756
AFDMLB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
355 AM EDT WED SEP 1 2004

.DISCUSSION...CURRENTLY...ISOLD ATLC SHOWERS AND A FEW TSTMS MOVING
ONSHORE ALONG THE COAST EARLY THIS MORNING. CAPE WIND PROFILER SHOWS
LOW LVL FLOW STRENGTHENING FROM THE SE IN THE 1-3 KFT LYR.

TODAY...ONSHORE FLOW PROGD THROUGH A DEEP LAYER WITH MOISTURE VALUES
REMAINING HIGH WITH PWATS AROUND 1.9 INCHES. HAVE KEPT POPS CLOSE TO
THE 40 PERCENT RANGE WITH MORNING ACTIVITY MOVING ONSHORE ALONG THE
COAST AND MID TO LATE AFTN SHOWER AND THUNDERSTORM ACTIVITY
PROGRESSING INTO THE INTERIOR. LESS BOUNDARY INTERACTIONS THIS AFTN
WITH STRONGER ONSHORE FLOW SO WILL HIGHLIGHT THE ONLY A FEW STRONG
STORMS IN THE HWO THIS MORNING. HIGHS 89-90 AT THE COAST AND LWR 90S
INLAND.

TONIGHT...WILL KEEP SLGT CHC FOR SHOWERS AND TSTMS ACROSS THE
INTERIOR IN THE EVENING AND ALSO KEEP A 20/30 PCT CHANCE FOR SHOWERS
ALONG THE COAST WITH ONSHORE FLOW INCREASING A BIT TWD MORNING
(SLIGHTLY HIGHER CHANCES FOR SRN CSTL SECTIONS). ANOTHER 'TROPICAL'
NIGHT WITH LOWS IN THE MID 70S...TO 77-80 DEGS FOR SRN CSTL BEACHES.

THU/THU NIGHT...NE/E GRADIENT FLOW GRADUALLY INCREASES WELL NORTHWEST
OF APPROACHING SEVERE HURRICANE FRANCES. GUSTY ONSHORE FLOW AND
SUFFICIENT MOISTURE SHOULD PROVIDE ENOUGH LOW LEVEL CONVERGENCE FOR
SCATTERED SHOWERS AND SOME STORMS...ALTHOUGH WITH SOME
DRYING/SUBSIDENCE NOTED IN ADVANCE OF FRANCES...WILL HOLD POPS NEAR
30 PERCENT.

FRI-SUN...IMPACT FROM HURRICANE FRANCES BECOMING MORE LIKELY...
ALTHOUGH MAGNITUDE STILL DICTATED BY EXACT FORECAST TRACK.
WITH AVERAGE FORECAST TRACK ERRORS AT TIME RANGE OF 3-4 DAYS OF 200-
250 MILES...IT IS STILL MUCH TO EARLY TO FOCUS UPON A SPECIFIC
LANDFALL LOCATION. MODEL GUIDANCE REMAINS DIVERSE WITH POSSIBILITIES
RANGING FROM MOVEMENT OFFSHORE PARALLEL TO THE EAST COAST TO LANDFALL
OVER THE PENINSULA. THE NHC FORECAST OBVIOUSLY IMPLIES A SERIOUS
THREAT TO EAST CENTRAL FLORIDA AND ALL RESIDENTS SHOULD REVIEW
PERSONAL HURRICANE PREPAREDNESS PLANS AND FOLLOW FORECASTS CLOSELY.
FRANCES IS A VERY LARGE HURRICANE AND ITS IMPACT WILL BE FELT FAR
FROM THE CENTER. WITH A GENERAL MOVEMENT TOWARD THE CWA...OUTER
RAINBANDS COULD APPROACH THE SE COAST BY FRIDAY MORNING. INCREASING
RAIN AND WINDS FORECAST TO SPREAD SE TO NW ACROSS CWA WITH GREATEST
IMPACT CURRENTLY EXPECTED SATURDAY. THE EXPECTED SLOW MOTION OF THE
HURRICANE MEANS CONDITIONS WILL BE SLOW TO IMPROVE SUNDAY.

THE POTENTIAL EXISTS FOR A PROLONGED PERIOD OF DAMAGING WINDS...
FLOODING RAINS...AND STORM SURGE. NHC ADVISORIES AND NWS MELBOURNE
FORECASTS WILL BEGIN TO BETTER DEFINE IMPACTS TO EAST CENTRAL FLORIDA
LATER TODAY AND THURSDAY.

NOTE THAT WIND FORECASTS ARE CAPPED AT 34 KNOTS IN THE 73 TO
120 HOUR PERIOD DUE TO FORECAST UNCERTAINTY AT EXTENDED RANGES. AS
THE HURRICANE IMPACTS MOVE TO WITHIN 72 HOURS...AND ESPECIALLY TO
WITHIN 36 HOURS...WIND SPEEDS WILL BE RAMPED UP SIGNIFICANTLY IF
NECESSARY.
MON-TUE...CONDITIONS WILL SLOWLY/GRADUALLY IMPROVE AS HURRICANE
DEPARTS. THE POTENTIAL EXISTS FOR TRAILING RAINBANDS TO LINGER
ACROSS THE REGION...AND HAVE BUMPED UP POPS TO ACCOUNT FOR
POSSIBILITY.

&&

.MARINE...WINDS BECOME EAST AND INCREASE TO 10 TO 15 KNOTS TONIGHT.
WILL GRADUALLY INCREASE SEAS TO 3 TO 5 FT RANGE AFTER MIDNIGHT WITH
HIGHER SEAS SRN LEG. WINDS WILL GRADUALLY INCREASE THURSDAY WITH
TROPICAL STORM FORCE WINDS AND SQUALLS POSSIBLY REACHING SOUTHERN
WATERS FRIDAY MORNING. SIGNIFICANTLY DETERIORATION EXPECTED LATER
FRIDAY THROUGH SATURDAY...LINGERING INTO SUNDAY AS WELL.

COORDINATED WITH MIA/TBW/JAX.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB 90 76 88 75 / 40 20 30 20
MCO 91 75 90 75 / 40 20 30 20
MLB 89 77 87 76 / 40 20 30 20
VRB 89 76 87 75 / 30 20 30 20

&&

.MLB WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...VOLKMER
LONG TERM...SPRATT



[James]

[James]

** WTNT41 KNHC 010832 ***
TCDAT1
HURRICANE FRANCES DISCUSSION NUMBER 30
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT WED SEP 01 2004

REPORTS FROM THE LATEST AIR FORCE RESERVE HURRICANE HUNTER
MONITORING FRANCES SHOW MAXIMUM FLIGHT-LEVEL WINDS AT 700 MB OF 123
KT...DOWN A LITTLE FROM THE EARLIER FLIGHT. HOWEVER...THE CENTRAL
PRESSURE HAS DROPPED TO 935 MB. BASED ON THIS...THE INITIAL
INTENSITY WILL REMAIN 120 KT FOR THIS ADVISORY. THE WSR-88D AT SAN
JUAN SHOWS THAT FRANCES HAS CONCENTRIC EYEWALLS...AND THE AIRCRAFT
DATA SHOWS THREE CONCENTRIC WIND MAXIMA. INDEED...ON THE LATEST
PASS THROUGH THE SOUTHEASTERN QUADRANT THE HIGHEST WIND WAS IN THE
MAXIMA ASSOCIATED WITH THE OUTER EYEWALL.

THE INITIAL MOTION IS A WOBBLY 285/15. FRANCES REMAINS ON THE SOUTH
SIDE OF A SUBTROPICAL RIDGE WHICH LARGE-SCALE MODELS FORECAST TO
WEAKEN SOMEWHAT OVER THE NEXT 72 HR. THIS SHOULD ALLOW THE
HURRICANE TO MOVE WEST-NORTHWESTWARD IN THE GENERAL DIRECTION OF
THE FLORIDA PENINSULA. DYNAMICAL MODEL GUIDANCE AGREES WITH THIS
SCENARIO...EXCEPT FOR THE GFDL WHICH CONTINUES TO CALL FOR A
UNREALISTIC LOOKING MOTION TOWARD THE NORTHWEST. THE OFFICIAL
FORECAST THROUGH 72 HR IS SHIFTED A LITTLE WEST OF THE PREVIOUS
TRACK BASED MAINLY ON THE INITIAL POSITION AND MOTION AND IS ON THE
LEFT SIDE OF THE DYNAMICAL GUIDANCE. AFTER 72 HR...THERE IS
DIVERGENCE IN THE GUIDANCE AS A SHORTWAVE RIDGE DEVELOPS NORTH OF
FRANCES OVER THE EASTERN UNITED STATES. THE OFFICIAL FORECAST
TRACK FOR THAT TIME IS SHIFTED TO THE SOUTHWEST OF THE PREVIOUS
TRACK...ALTHOUGH NOT AS FAR AS THE UKMET WHICH MARCHES FRANCES
WESTWARD ACROSS CENTRAL FLORIDA AND INTO THE GULF OF MEXICO.

THE INTENSITY FORECAST IS MODIFIED ONLY SLIGHTLY FROM THE PREVIOUS
PACKAGE. UPPER-LEVEL WINDS ARE FAVORABLE THROUGH AT LEAST 36-48
HR...SO FRANCES SHOULD REMAIN STRONG. A SLIGHT WEAKENING IS
INDICATED AT 72 HR BASED ON LAND INTERACTION AND SOME POSSIBLE
WESTERLY SHEAR. THE MAIN CONTROLLING FACTOR ON INTENSITY WILL BE
THE STRUCTURE OF FRANCES AND CONCENTRIC EYEWALL CYCLES...BOTH OF
WHICH ARE DIFFICULT AT BEST TO TIME. GIVEN THE CURRENT STRUCTURE
OF THE HURRICANE...CHANGES IN INTENSITY WILL LIKELY BE RELATIVELY
SLOW TO OCCUR.

FORECASTER BEVEN

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/0900Z 21.2N 68.5W 120 KT
12HR VT 01/1800Z 22.0N 70.6W 125 KT
24HR VT 02/0600Z 23.2N 72.9W 125 KT
36HR VT 02/1800Z 24.3N 74.8W 130 KT
48HR VT 03/0600Z 25.5N 76.6W 130 KT
72HR VT 04/0600Z 27.0N 79.5W 125 KT
96HR VT 05/0600Z 28.5N 81.5W 85 KT...INLAND
120HR VT 06/0600Z 31.0N 84.0W 35 KT...INLAND


$$

[ColinD]

Hurricane Frances Discussion Number 30

Statement as of 5:00 am EDT on September 01, 2004


reports from the latest Air Force Reserve hurricane hunter
monitoring Frances show maximum flight-level winds at 700 mb of 123
kt...down a little from the earlier flight. However...the central
pressure has dropped to 935 mb. Based on this...the initial
intensity will remain 120 kt for this advisory. The WSR-88D at San
Juan shows that Frances has concentric eyewalls...and the aircraft
data shows three concentric wind maxima. Indeed...on the latest
pass through the southeastern quadrant the highest wind was in the
maxima associated with the outer eyewall.

The initial motion is a wobbly 285/15. Frances remains on the south
side of a subtropical ridge which large-scale models forecast to
weaken somewhat over the next 72 hr. This should allow the
hurricane to move west-northwestward in the general direction of
the Florida Peninsula. Dynamical model guidance agrees with this
scenario...except for the GFDL which continues to call for a
unrealistic looking motion toward the northwest. The official
forecast through 72 hr is shifted a little west of the previous
track based mainly on the initial position and motion and is on the
left side of the dynamical guidance. After 72 hr...there is
divergence in the guidance as a shortwave ridge develops north of
Frances over the eastern United States. The official forecast
track for that time is shifted to the southwest of the previous
track...although not as far as the UKMET which marches Frances
westward across central Florida and into the Gulf of Mexico.


The intensity forecast is modified only slightly from the previous
package. Upper-level winds are favorable through at least 36-48
hr...so Frances should remain strong. A slight weakening is
indicated at 72 hr based on land interaction and some possible
westerly shear. The main controlling factor on intensity will be
the structure of Frances and concentric eyewall cycles...both of
which are difficult at best to time. Given the current structure
of the hurricane...changes in intensity will likely be relatively
slow to occur.


Forecaster Beven


forecast positions and Max winds


initial 01/0900z 21.2n 68.5w 120 kt
12hr VT 01/1800z 22.0n 70.6w 125 kt
24hr VT 02/0600z 23.2n 72.9w 125 kt
36hr VT 02/1800z 24.3n 74.8w 130 kt
48hr VT 03/0600z 25.5n 76.6w 130 kt
72hr VT 04/0600z 27.0n 79.5w 125 kt
96hr VT 05/0600z 28.5n 81.5w 85 kt...inland
120hr VT 06/0600z 31.0n 84.0w 35 kt...inland

[Derek Ortt]

http://www.nwhhc.com/atl062004forecast.html


not seeing anything that makes me change the landfall location yet, though an ever so slight adjustment to the path there

[ColinD]

You've been spot on so far, man. I read your abstract the other day on water vapor and tropical system intensity changes. Do you include those findings in your intensity estimates?

[Thunder44]

TPC mentions land interaction (I'm assuming the Bahamas) and westerly shear affect Frances before making landfall in Florida. So the weaken it a bit in the official forecast. How realistic is this? If there is weakening, how significant could this be?

[Stormsfury]

Bahama land interaction won't be significant at all, wind shear might be a different story should this materialize later in the period ... to maintain a hurricane of this intensity, conditions have to be nearly perfect, and minor disruptions to the outflow can sometimes play significant in the (de)organization of a major hurricane ...

More likely, though, the intensity will dictated by inner core structure and eyewall replacement cycles (ERC's) ...

SF

[Derek Ortt]

yes I do include those findings, including some others that I have not yet released regarding shear

[StrongWind]

Mr. Ortt's link shows that Frances is expected to be near 27.0N 80.0W 120KT at 72Hrs. This is around Port St. Lucie (by my guesstimate) - south of prev. landfalls.

But, the Sun-Sentinel says:

"By Ken Kaye
Sun-Sentinel
Posted September 1 2004, 3:28 AM EDT

Forecasters on Tuesday shifted the track for Hurricane Frances farther north, with a possible landfall near Daytona Beach on Saturday afternoon. That reduces but far from eliminates the threat to this region. "

There is of course a lot of if's, or's and but's, but the above is what most people will pick out of the article.

SW

[ColinD]

Mr. Ortt's link shows that Frances is expected to be near 27.0N 80.0W 120KT at 72Hrs. This is around Port St. Lucie (by my guesstimate) - south of prev. landfalls.

But, the Sun-Sentinel says:

"By Ken Kaye
Sun-Sentinel
Posted September 1 2004, 3:28 AM EDT

Forecasters on Tuesday shifted the track for Hurricane Frances farther north, with a possible landfall near Daytona Beach on Saturday afternoon. That reduces but far from eliminates the threat to this region. "

There is of course a lot of if's, or's and but's, but the above is what most people will pick out of the article.

SW

Right, and in the past hour the NHC shifted back further South to South Central/South Florida-ish. Somewhere a little North of West Palm.

Shifted South some last night too.

Newspaper articles are going to be quickly outdated in such a rapidly changing situation.

[Matthew5]

A eye wall replacement is happening right now! I think by this afternoon we should be looking down a 25 to 30 mile wide eye again.

[Bammer89]

Local Ft. Lauderdale mets pretty low key, even though suggesting a late Friday or early Saturtday strike between West Palm and Melbourne. I think its sooner and further south.

[ColinD]

Local Ft. Lauderdale mets pretty low key, even though suggesting a late Friday or early Saturtday strike between West Palm and Melbourne. I think its sooner and further south.

3 days to go. Wherever and whenever the watches go up the runs on the stores are going to insane. I'm getting my final supplies today. Food, ice, batteries, full tank of gas and lots of cash.

[StrongWind]

By Ken Kaye
Sun-Sentinel
Posted September 1 2004, 5:21 AM EDT


As of now, that's his story and he's sticking to it.

[jlauderdal]

TPC mentions land interaction (I'm assuming the Bahamas) and westerly shear affect Frances before making landfall in Florida. So the weaken it a bit in the official forecast. How realistic is this? If there is weakening, how significant could this be?

bahamas are flat as pancake and small...no effect..nhs discussion mentions their modeling shows some due to land interaction but that is just noise in the model. they ehan say that changes would be slow and the hurricane itself has more effect on intensity than the land it would be going over.

[ColinD]

By Ken Kaye
Sun-Sentinel
Posted September 1 2004, 5:21 AM EDT


As of now, that's his story and he's sticking to it.

He should. What he said was true. On Tuesday the official forecast track was shifted Northward. Today is Wednesday and it has been shifted Southward.

The National Hurricane Center 5 am discussion stated

"The official forecast through 72 hr is shifted a little west of the previous
track based mainly on the initial position and motion and is on the
left side of the dynamical guidance. After 72 hr...there is divergence in the guidance as a shortwave ridge develops north of
Frances over the eastern United States. The official forecast
track for that time is shifted to the southwest of the previous
track "