Wednesday, August 24, 2011

Hurricane Irene A Potentially Historic Storm
















000

WTNT34 KNHC 250255
TCPAT4

BULLETIN HURRICANE IRENE ADVISORY NUMBER 19
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 PM EDT WED AUG 24 2011

...HURRICANE IRENE DANGEROUSLY APPROACHING THE NORTHWESTERN
BAHAMAS...AT 1100 PM EDT...0300 UTC...THE EYE OF HURRICANE IRENE WAS

.....LOCATED NEAR LATITUDE 23.8 NORTH...LONGITUDE 75.4 WEST. IRENE IS
MOVING TOWARD THE NORTHWEST NEAR 12 MPH...19 KM/H. A TURN TOWARD
THE NORTH-NORTHWEST AND THEN TOWARD THE NORTH ARE EXPECTED ON
THURSDAY. ON THE FORECAST TRACK...THE CORE OF IRENE WILL CONTINUE
TO MOVE ACROSS THE CENTRAL BAHAMAS DURING THE NEXT SEVERAL HOURS
AND MOVE OVER THE NORTHWESTERN BAHAMAS ON THURSDAY.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 120 MPH...195 KM/H...WITH HIGHER
GUSTS. IRENE IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME FLUCTUATIONS IN INTENSITY ARE LIKELY
DURING THE NEXT SEVERAL HOURS...BUT SOME STRENGTHENING IS FORECAST
DURING THE NEXT DAY OR SO. IRENE COULD BECOME A CATEGORY FOUR
HURRICANE ON THURSDAY.

IRENE IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND
OUTWARD UP TO 70 MILES...110 KM...FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 255 MILES...410 KM.

A RECONNAISSANCE PLANE ESTIMATED A MINIMUM CENTRAL PRESSURE OF 952
MB...28.11 INCHES.
000

FXUS61 KCAR 250250
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
1050 PM EDT WED AUG 24 2011.....LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...


PRIMARY CONCERN THIS FORECAST PERIOD IS HURRICANE IRENE. WIND
GRIDS MAIN FOCUS AT THIS POINT. AFTER TALKING WITH OFFICES TO
SOUTH HAVE DECIDED TO GENERATE THE WIND GRIDS WITH GFS40 THEN USE
THE GMOS FOR REMAINDER OF GRIDS. EXPECT HURRICANE IRENE TO MOVE TO
A POSITION OFF THE MID ATLANTIC STATES BY SUNDAY MORNING THEN MOVE
NORTHWARD TO MAINE COAST BY LATE SUNDAY EVENING. WITH WELL OVER
100 HOURS TO THE POSSIBLE ARRIVAL OF THE SYSTEM THERE IS STILL
PLENTY OF UNCERTAIN. HAVE MADE SOME MINOR ADJUSTMENTS TO GMOS POP
AND SKY GRIDS. FOR TIDAL ISSUES THE HIGH TIDE SUNDAY NIGHT IS JUST
PRIOR TO 11:00 PM IS OF MOST CONCERN FOR POSSIBLE COASTAL FLOODING
ISSUES. SO WILL ALSO MONITOR THE TIMING OF IRENE DURING THE NEXT
SEVERAL DAYS SINCE THIS WILL BE CRITICAL WITH LARGE TIDAL RANGE
ALONG EASTERN MAINE COAST.SHORT TERM: HAVE USED A BLEND OF THE NAM12 AND GFS40 FOR WINDS

.MARINE...



.........TRACK OF HURRICANE IRENE WILL BE CRITICAL TO FORECAST SUNDAY
AND SUNDAY NIGHT. FOR WAVES: LONG PERIOD WAVES FROM HURRICANE
IRENE WILL ALREADY BE ARRIVING ALONG THE MAINE COAST AT THE
BEGINNING OF THIS PERIOD AND WILL GRADUALLY INCREASE IN HEIGHT
SATURDAY NIGHT INTO THE DAY SUNDAY. WILL USE WNA/4 WHICH IS IN
LINE WITH HURRICANE VERSION OF WAVE MODEL TO GENERATE THE WAVE
GRIDS.


EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
313 PM EDT WED AUG 24 2011

VALID 12Z SAT AUG 27 2011 - 12Z WED AUG 31 2011

...DANGEROUS HURRICANE IRENE TO AFFECT THE NC OUTER BANKS INTO THE
NORTHEAST THIS WEEKEND...

IRENE CONTINUES TO STRENGTHEN AS A CATEGORY 3 HURRICANE OVER THE
BAHAMAS AND AS OF 18Z WAS PACKING SUSTAINED WINDS OF 120 MPH WITH
HIGHER GUSTS. IRENE COULD REACH CATEGORY 4 STATUS BY THURSDAY.
PLEASE REFER A UPDATES FROM THE NATIONAL HURRICANE CENTER AND
LOCAL WEATHER OFFICE/AGENCIES FOR ADDITIONAL INFORMATION ON IRENE.

DUE IN PART TO MORE FREQUENT SAMPLING OF THE ENVIRONMENTAL
CONDITIONS SURROUNDING HURRICANE IRENE BY MULTIPLE AIRPLANE
PLATFORMS ALONG WITH CONTINUATION OF SUPPLEMENTAL UPPER AIR RAOBS
ACROSS PARTS OF THE EASTERN CONUS EVERY 6 HOURS...THE MODEL
SOLUTION SPREAD FOR THE TRACK OF IRENE FOR MOST GUIDANCE OVER THE
NEXT 4-5 DAYS OVERALL SEEMS REDUCED FOR THE LONGER RANGES. THAT
SAID...EVEN RELATIVELY SMALL DIFFERENCES CAN MAKE A SIGNIFICANT
DIFFERENCE ON THE EXTENT OF SYSTEM EFFECT LOCALLY AS TRACKS VARY
FROM RUN TO RUN WITH RESPECT TO HOW FAR TO THE WEST/INLAND IRENE
MAY GO.

IN ADDITION TO IRENE INTENSITY IN GUIDANCE...ONE OF THE LARGEST
REMAINING UNCERTAINTIES IN THE MEDIUM RANGE PERIOD HOWEVER IS THE
EXACT SPEED AND STRENGTH OF A STRONG SHORTWAVE TROUGH CURRENTLY
ENTERING WESTERN CANADA. THIS TROUGH IS EXPECTED TO AMPLIFY DOWN
FROM ONTARIO/QUEBEC BY DAY 3/SAT AND PICK UP IRENE. THE GFS/ECMWF
HAVE NEARLY CONVERGED WITH THE DETAILS OF THIS TROUGH...WITH THE
GFS ONLY SLIGHTLY FASTER AND SUPPORTED BY THE CANADIAN...THUS
ACCELERATING IRENE NORTHWARD INTO THE NORTHEAST/NEW ENGLAND AND
BEYOND MORE QUICKLY THAN THE ECMWF. HOWEVER...RUN-TO-RUN
VARIABILITY WITH THE MORE UNCERTAIN HIGHER LATITUDE FLOW IS TO BE
EXPECTED...WITH RECENT GFS/ECMWF 4-CYCLE LAGGED AVERAGE FORECASTS
SHOWING 500 MB HEIGHT VARIABILITIES AVERAGING 50 TO 70 DECAMETERS
ACROSS THE UPPER GREAT LAKES...ENOUGH TO SUPPORT DIFFERING
INFLUENCES ON IRENE.

GFS/ECMWF AGREEMENT ELSEWHERE SEEMED SUFFICIENT TO USE NEARLY
EQUALLY FOR THE PRELIMINARY AND NOW FINAL PRESSURES/FRONTS OVERALL
ACROSS MUCH OF THE CONUS. THIS APPROACH WORKS WELL FOR THE WESTERN
AND CENTRAL CONUS IN PARTICULAR AS THE STRONG FLOW ACROSS THE
NORTHERN PACIFIC IS EXPECTED TO SUPPORT CONTINUED STRENGTH AND
TIMING DIFFERENCES OF INDIVIDUAL SHORTWAVE TROUGHS WHICH ARE BEST
RESOLVED WITH AN INTERMEDIATE APPROACH. ONE DIFFERENCE SEEN IN THE
LATEST GUIDANCE IS FOR GREATER AMPLIFICATION OF A SIGNIFICANT
SHORTWAVE TROUGH ACROSS THE PACIFIC NORTHWEST DAYS 6/7...WITH THE
ECMWF FASTER IN EJECTING THE LEADING EDGE OF THE TROUGH OUT OF THE
NORTHWEST COMPARED TO THE GFS...WHICH THEN LEADS TO GROWING
DIFFERENCES DOWNSTREAM. THE 00Z CANADIAN AND THE GLOBAL ENSEMBLE
MEANS PROVIDE GOOD SUPPORT FOR A SOLUTION CLOSEST TO THE
GFS...LEANING AWAY FROM THE 00/12 UTC ECMWF THERE STARTING DAY
6/TUE...AND INSTEAD BLEND THE GFS/GEFS MEAN SOLUTIONS FOR DAYS
6/7.

JAMES/SCHICHTEL

Hurricane Irene Update Five


000

WTNT34 KNHC 242354
TCPAT4

BULLETIN
HURRICANE IRENE INTERMEDIATE ADVISORY NUMBER 18A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
800 PM EDT WED AUG 24 2011

...EYE OF DANGEROUS HURRICANE IRENE MOVING BETWEEN RUM CAY AND LONG
ISLAND IN THE BAHAMAS...THE EYE OF HURRICANE IRENE IS MOVING BETWEEN LONG ISLAND AND RUM CAY

IN THE BAHAMAS...AND AT 800 PM EDT...0000 UTC...IT WAS LOCATED NEAR
LATITUDE 23.5 NORTH...LONGITUDE 75.0 WEST. IRENE IS MOVING TOWARD
THE NORTHWEST NEAR 12 MPH...19 KM/H...AND THIS GENERAL MOTION IS
EXPECTED TO CONTINUE THROUGH TONIGHT. A TURN TOWARD THE
NORTH-NORTHWEST AND THEN TOWARD THE NORTH ARE EXPECTED THURSDAY AND

THURSDAY NIGHT. ON THE FORECAST TRACK...THE CORE OF IRENE WILL
MOVE ACROSS THE CENTRAL BAHAMAS TONIGHT AND OVER THE NORTHWESTERN
BAHAMAS ON THURSDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 120 MPH...195 KM/H...WITH HIGHER
GUSTS. IRENE IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME ADDITIONAL STRENGTHENING IS FORECAST
DURING THE NEXT DAY OR SO...AND IRENE COULD BECOME A CATEGORY FOUR
HURRICANE BY THURSDAY. AN AIR FORCE PLANE IS CURRENTLY APPROACHING
IRENE.

IRENE IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND
OUTWARD UP TO 60 MILES...95 KM...FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 230 MILES...370 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 954 MB...28.17 INCHES. AN
AUTOMATIC WEATHER STATION ON LONG ISLAND IN THE BAHAMAS REPORTED A
MINIMUM PRESSURE OF 969.1 MB...28.62 INCHES AT 700 PM EDT...2300
UTC...AS THE EYE PASSED NEAR THE STATION.

Hurricane Irene Update Four

WOCN31 CWHX 241745

Tropical cyclone information statement issued by the Canadian
Hurricane Centre of Environment Canada at 3:29 PM ADT Wednesday
24 August 2011.
---------------------------------------------------------------------

Tropical cyclone information statement for:
=new= Atlantic provinces
=new= Southern Quebec.

For hurricane Irene.

The next statement will be issued by 9:00 AM ADT.

This is a preliminary information statement to discuss the
Timing of potential impact of hurricane Irene in Canada.

An updated statement is planned for 9 AM ADT Thursday.
---------------------------------------------------------------------

==discussion==

Hurricane Irene is a major hurricane moving through the Bahamas with
winds near 200 km/h. The hurricane is forecast to track toward the
northwest then north very near or just off the east coast of the
United States. It is quite likely that Irene will impact eastern
Canadian territory late this coming weekend and/or early next week.
The track and intensity will, as always, depend on many changing
factors over a period of several days. Thus, it is too early to
meaningfully state how the storm will affect particular areas.
At this point in time we encourage checking the forecasts at least
twice a day through the rest of this week and the weekend.

Visit weatheroffice.Gc.Ca/hurricane (all in lower case) for the
latest hurricane track information map.

Please also refer to the public and marine forecasts and warnings
issued by Environment Canada for your area.

END/FOGARTY

Hurricane Irene Update Three


000

WTNT34 KNHC 241742
TCPAT4

BULLETIN
HURRICANE IRENE INTERMEDIATE ADVISORY NUMBER 17A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
200 PM EDT WED AUG 24 2011

...IRENE A LITTLE STRONGER...EYE OVER CROOKED ISLAND...AT 200 PM EDT...1800 UTC...THE CENTER OF HURRICANE IRENE WAS

LOCATED NEAR LATITUDE 22.7 NORTH...LONGITUDE 74.3 WEST. IRENE IS
MOVING TOWARD THE NORTHWEST NEAR 12 MPH...19 KM/H...AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE THROUGH TONIGHT. A TURN
TOWARD THE NORTH-NORTHWEST AND THEN NORTH ARE EXPECTED THURSDAY
AND THURSDAY NIGHT. ON THE FORECAST TRACK...THE CORE OF IRENE
WILL MOVE ACROSS THE SOUTHEASTERN AND CENTRAL BAHAMAS THROUGH
TONIGHT AND OVER THE NORTHWESTERN BAHAMAS ON THURSDAY.

DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE
THAT THE MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 120 MPH...
195 KM/H...WITH HIGHER GUSTS. IRENE IS A CATEGORY THREE HURRICANE
ON THE SAFFIR-SIMPSON HURRICANE WIND SCALE. SOME ADDITIONAL
STRENGTHENING IS FORECAST DURING THE NEXT DAY OR SO AND IRENE COULD
BECOME A CATEGORY FOUR HURRICANE BY THURSDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 50 MILES...85 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205
MILES...335 KM.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY RECONNAISSANCE
AIRCRAFT WAS 954 MB...28.17 INCHES.