NHC Public Advisory #21 (next update at 7:00 p.m. CDT)

[Penndems]

Link: http://www.nhc.noaa.gov/
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000
WTNT33 KNHC 222049
TCPAT3
BULLETIN
HURRICANE RITA ADVISORY NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
4 PM CDT THU SEP 22 2005

...DANGEROUS HURRICANE RITA GRADUALLY HEADING TOWARD THE SOUTHWEST
LOUISIANA AND UPPER TEXAS COASTS...

A HURRICANE WARNING IS IN EFFECT FROM PORT O'CONNOR TEXAS TO MORGAN
CITY LOUISIANA. A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS
ARE EXPECTED WITHIN THE WARNING AREA WITHIN THE NEXT 24 HOURS.
PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO
COMPLETION.

AT 4 PM CDT...2100Z...A TROPICAL STORM WARNING HAS BEEN ISSUED FOR
NORTH OF THE MOUTH OF THE MISSISSIPPI RIVER TO THE MOUTH OF THE
PEARL RIVER INCLUDING METROPOLITAN NEW ORLEANS AND LAKE
PONTCHARTRAIN. A TROPICAL STORM WARNING IS NOW IN EFFECT FOR THE
SOUTHEASTERN COAST OF LOUISIANA EAST OF MORGAN CITY TO THE MOUTH OF
THE MOUTH OF THE PEARL RIVER INCLUDING METROPOLITAN NEW ORLEANS AND
LAKE PONTCHARTRAIN....AND FROM SOUTH OF PORT O'CONNOR TO PORT
MANSFIELD TEXAS. A TROPICAL STORM WARNING MEANS THAT TROPICAL
STORM CONDITIONS ARE EXPECTED WITHIN THE WARNING AREA WITHIN THE
NEXT 24 HOURS.

A TROPICAL STROM WATCH REMAINS IN EFFECT FROM SOUTH OF PORT
MANSFIELD TO BROWNSVILLE TEXAS...AND FOR THE NORTHEASTERN COAST OF
MEXICO FROM RIO SAN FERNANDO NORTHWARD TO THE RIO GRANDE.
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 36 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 4 PM CDT...2100Z...THE CENTER OF HURRICANE RITA WAS LOCATED NEAR
LATITUDE 25.8 NORTH...LONGITUDE 89.5 WEST OR ABOUT 405 MILES...
650 KM...SOUTHEAST OF GALVESTON TEXAS AND ABOUT 390 MILES... 630
KM...SOUTHEAST OF PORT ARTHUR TEXAS.

RITA IS MOVING TOWARD THE WEST-NORTHWEST NEAR 9 MPH...15 KM/HR. A
GRADUAL TURN TOWARD THE NORTHWEST IS EXPECTED DURING THE NEXT 24
HOURS. ON THIS TRACK...THE CORE OF RITA WILL BE APPROACHING THE
SOUTHWEST LOUISIANA AND THE UPPER TEXAS COAST LATE FRIDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 145 MPH...230 KM/HR...WITH HIGHER
GUSTS. RITA IS A EXTREMELY DANGEROUS CATEGORY FOUR HURRICANE ON THE
SAFFIR-SIMPSON SCALE. SOME FLUCTUATIONS IN INTENSITY ARE LIKELY
DURING THE NEXT 24 HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 60 MILES... 95 KM...
FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP
TO 205 MILES...335 KM. ANYTROPICAL STROM FORCE WINDS IN THE NEW
ORLEANS AREA ARE EXPECTED TO BE CONFINED TO A FEW SQUALLS
ASSOCIATED WITH QUICKLY MOVING RAINBANDS. AT 3 PM CDT...A NOAA BUOY
REPORTED A 10-MINUTE AVERAGE WIND OF 89 MPH...143 KM/HR WITH A GUST
TO 112 MPH...180 KM/HR.

LATEST MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE PLANE WAS
913 MB...26.96 INCHES.

COASTAL STORM SURGE FLOODING OF 15 TO 20 FEET ABOVE NORMAL TIDE
LEVELS...ALONG WITH LARGE AND DANGEROUS BATTERING WAVES...CAN BE
EXPECTED NEAR AND TO THE EAST OF WHERE THE CENTER MAKES LANDFALL.
TIDES ARE CURRENTLY RUNNING ABOUT 2 FEET ABOVE NORMAL ALONG THE
LOUISIANA...MISSISSIPPI AND ALABAMA COASTS IN THE AREAS AFFECTED BY
KATRINA. TIDES IN THOSE AREAS WILL INCREASE TO 3 TO 5 FEET AND BE
ACCOMPANIED BY LARGE WAVES...AND RESIDENTS THERE COULD EXPERIENCE
COASTAL FLOODING.

RAINFALL ACCUMULATIONS OF 8 TO 12 INCHES WITH ISOLATED MAXIMUM 15
INCH TOTALS ARE POSSIBLE ALONG THE PATH OF RITA OVER SOUTHEAST TEXAS
AND SOUTHWESTERN LOUISIANA AS IT MOVES INLAND. BASED ON THE
FORECAST TRACK...TOTALS ACCUMULATIONS IN EXCESS OF 25 INCHES ARE
POSSIBLE OVER THE NEXT SEVERAL DAYS AS THE SYSTEM SLOWS DOWN. IN
ADDITION...RAINFALL AMOUNTS OF 3 TO 5 INCHES ARE POSSIBLE OVER
SOUTHEASTERN LOUISIANA INCLUDING NEW ORLEANS.

REPEATING THE 4 PM CDT POSITION...25.8 N... 89.5 W. MOVEMENT
TOWARD...WEST-NORTHWEST NEAR 9 MPH. MAXIMUM SUSTAINED WINDS...145
MPH. MINIMUM CENTRAL PRESSURE... 913 MB.

AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE
CENTER AT 7 PM CDT FOLLOWED BY THE NEXT COMPLETE ADVISORY AT 10 PM
CDT.

FORECASTER AVILA

$$
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000
WTNT43 KNHC 222049
TCDAT3
HURRICANE RITA DISCUSSION NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT THU SEP 22 2005

RITA IS GOING TROUGH THE WEAKENING PHASE OF AN EYEWALL REPLACEMENT
CYCLE AND DATA FROM THE NOAA RECONNAISSANCE PLANE INDICATE THAT
WINDS HAVE DECREASED TO 125 KNOTS...AND THIS MAY BE GENEROUS.
HOWEVER...THE MINIMUM CENTRAL PRESSURE HAS REMAINED AROUND 913
MB...WHICH IS A VERY LOW PRESSURE TO HAVE ONLY 125 KNOTS. IN
ADDITION TO THE EYEWALL REPLACEMENT CYCLE...RITA IS CURRENTLY
MOVING OVER THE EDGE OF A COLD SST EDDY. THIS COULD HAVE ENHANCED
THE WEAKENING TODAY. THE HURRICANE IS FORECAST TO MOVE OVER ANOTHER
WARM EDDY DURING THE NEXT 12 TO 24 HOURS AND THERE IS SOME CHANCE
THAT RITA COULD REGAIN SOME INTENSITY. BECAUSE THE SHEAR IS
FORECAST TO INCREASE...THIS MAY COMPENSATE FOR THE STRENGTHENING
THAT MAY BE CAUSED BY THE EFFECTS OF THE HIGH HEAT CONTENT. THE
BEST OPTION AT THIS TIME IS TO KEEP RITA AS A 125 KT HURRICANE WITH
A SLIGHT WEAKENING BEFORE LANDFALL. THE BOTTOM LINE IS THAT RITA
IS EXPECTED TO MAKE LANDFALL AS A DANGEROUS HURRICANE OF AT LEAST A
CATEGORY THREE INTENSITY.

RITA IS MOVING TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 8 KNOTS.
THE FORECAST TRACK HAS NOT CHANGED AND RITA IS EXPECTED TO BE
STEERED TOWARD THE WEST-NORTHWEST AND NORTHWEST TOWARD THE
UPPER-TEXAS OR THE WESTERN LOUISIANA COASTS AS THE HIGH SHIFTS
EASTWARD. AFTER LANDFALL...STEERING CURRENTS ARE EXPECTED TO WEAKEN
AND THE CYCLONE COULD MEANDER FOR A COUPLE OF DAYS IN THE VICINITY
OF NORTHEASTERN TEXAS...PRODUCING HEAVY RAINS.

BASED ON THE FORECAST TRACK AND WIND RADII...THE TROPICAL STORM
WARNING HAS BEEN EXTENDED EASTWARD AND NORTHWARD ALONG THE
LOUISIANA COAST. ANY TROPICAL STORM FORCE WINDS IN THE NEW ORLEANS
AREA ARE EXPECTED TO BE CONFINED TO A FEW SQUALLS ASSOCIATED WITH
QUICKLY MOVING RAINBANDS.

FORECASTER AVILA


FORECAST POSITIONS AND MAX WINDS

INITIAL 22/2100Z 25.8N 89.5W 125 KT
12HR VT 23/0600Z 26.5N 90.7W 125 KT
24HR VT 23/1800Z 27.8N 92.4W 125 KT
36HR VT 24/0600Z 29.2N 93.8W 120 KT
48HR VT 24/1800Z 30.5N 94.5W 75 KT...INLAND
72HR VT 25/1800Z 33.0N 95.0W 40 KT...INLAND
96HR VT 26/1800Z 33.0N 95.0W 25 KT...INLAND
120HR VT 27/1800Z 33.0N 95.0W 25 KT...INLAND


$$
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[Zynx]

1. That pressure is very low for that strength of wind.

I don't know what that means, but it seems strange that 913 mb = 145 mph winds when not much lower equals 165 or 175 mph.

[Penndems]

2. 913/145 sounds about right to me

Rita's a CAT 4 with wind speeds between 131-155 mph. If the barometric pressure drops again to a CAT 5 level (low 900-high 800), the winds will pick up to 155 mph and over.

I could be wrong, but the wind speed certainly seems to be in keeping with the BP.