Hurricane Irene A Potential Long Range Threat To The Region No. 2

000

WTNT34 KNHC 240258
TCPAT4

BULLETIN
HURRICANE IRENE ADVISORY NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 PM EDT TUE AUG 23 2011

...WEATHER RAPIDLY DETERIORATING IN THE SOUTHEASTERN BAHAMAS AS
HURRICANE IRENE APPROACHES...AT 1100 PM EDT...0300 UTC...THE CENTER OF HURRICANE IRENE WAS

LOCATED NEAR LATITUDE 21.3 NORTH...LONGITUDE 72.4 WEST. IRENE IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 9 MPH...15 KM/H. A GRADUAL
TURN TOWARD THE NORTHWEST IS EXPECTED ON WEDNESDAY. ON THE
FORECAST TRACK...THE CORE OF IRENE WILL MOVE ACROSS THE
SOUTHEASTERN AND CENTRAL BAHAMAS ON WEDNESDAY AND THE NORTHWESTERN BAHAMAS ON THURSDAY.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 90 MPH...150 KM/H...WITH HIGHER
GUSTS. IRENE IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. STRENGTHENING IS FORECAST AND IRENE COULD BECOME A
MAJOR HURRICANE DURING THE NEXT DAY OR SO.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 40 MILES...65 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205
MILES...335 KM.

LATEST MINIMUM CENTRAL PRESSURE REPORTED BY BOTH AIR FORCE AND NOAA
HURRICANE HUNTER PLANES WAS 969 MB...28.61 INCHES.00

FXUS61 KCAR 240300

AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
1100 PM EDT TUE AUG 23 2011

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

THE MAIN CONCERN DURING THIS PERIOD WILL OF COURSE BE WITH REGARD
TO TROPICAL SYSTEM IRENE AND IT EVENTUAL IMPACTS. HIGH PRESSURE
WILL REMAIN ACROSS THE REGION FRIDAY NIGHT BEFORE MOVING EAST
DURING SATURDAY. ATTENTION THEN TURNS TO IRENE AS IT BEGINS TO
MOVE NORTH ALONG OR JUST TO THE EAST OF THE EASTERN SEABOARD LATER
SATURDAY THROUGH SUNDAY...BEFORE TRACKING NEAR THE MAINE COAST
SUNDAY NIGHT INTO MONDAY. STILL PLENTY OF UNCERTAINTY WITH REGARD
TO THE EXACT TRACK OF THE SYSTEM SO PLEASE CONTINUE TO MONITOR
THE LATEST INFORMATION FROM THE NATIONAL HURRICANE CENTER. THIS
SYSTEM WILL POTENTIALLY BRING WIND AND RAIN TO THE REGION LATER
SUNDAY AND INTO MONDAY. WILL CONTINUE TO REFERENCE IN THE HWO
PRODUCT. CONDITIONS SHOULD IMPROVE BEHIND THE SYSTEM MONDAY NIGHT
AND TUESDAY.
EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
336 PM EDT TUE AUG 23 2011

VALID 12Z FRI AUG 26 2011 - 12Z TUE AUG 30 2011

...HURRICANE IRENE TO STRONGLY AFFECT MUCH OF THE EASTERN SEABOARD
THIS WEEKEND...

PRELIMINARY UPDATE:

ON A LARGER SCALE MODELS SHOW GOOD AGREEMENT THROUGH THE MEDIUM
RANGE PERIOD WITH MAINTAINING AN UPPER VORTEX NEAR HUDSON BAY AND
AN UPPER HIGH OVER THE S. PLAINS...WITH VERY PROGRESSIVE FLOW
BETWEEN THAT HELPS TO SUSTAIN A MEAN EAST COAST TROUGH ONCE
INDIVIDUAL DISTURBANCES EXIT CENTRAL CANADA. ASIDE FROM HURRICANE
IRENE...DAY-TO-DAY SOLUTION DIFFERENCES ARE RELATIVELY SMALL AS
WELL AT LEAST UNTIL LATE IN THE PERIOD. THE LATEST NHC FORECAST IS
BETWEEN THE 00Z UKMET/ECMWF SOLUTIONS...WITH THE 00Z GFS SLIGHTLY
FASTER UNTIL ABOUT DAY 6/MON WHEN THE GFS IS CLOSET. THUS...DUE TO
THE SIGNIFICANCE OF IRENE WILL LIKELY USE THESE 3 MODELS THE MOST
IN CONSTRUCTING THE PRELIMINARY PRESSURES/FRONTS FOR THE MEDIUM
RANGE PERIOD. EVEN WITH RELATIVELY CLOSE DYNAMICAL TRACK GUIDANCE
TO IMPLEMENT IN THE UPCOMING PROGS...NO SOLUTION OTHER THAN THE
00Z ECMWF IS EVEN REMOTELY CLOSE TO THE HURRICANE MODEL GUIDANCE
CENTRAL PRESSURES SUCH AS THE GHM/HWRF WHICH HAVE IRENE BOTTOMING
OUT AROUND 930 MB AND SHIFTING TO THE LEFT OF THE OFFICIAL NHC
TRACK ALONG THE SOUTH CAROLINA COAST. HOWEVER...WHEN CONSIDERING
THE ENTIRE SOLUTION SPREAD JUST BY DAY 4/SAT...TRACK DIFFERENCES
SPAN ABOUT 300 NM...SO THERE REMAINS MUCH TO RESOLVE FOR THE
SENSIBLE WEATHER DETAILS OF IRENE. FOR NOW...WILL INTERPOLATE
BETWEEN THE LATEST NHC POINTS FOR DAYS 3 AND 4 WHICH HAS IRENE
MAKING LANDFALL BETWEEN MYRTLE BEACH SC AND WILMINGTON NC LATE
SATURDAY. REFER TO THE NHC FOR THE OFFICIAL TRACK AND INTENSITY

FORECAST.

ELSEWHERE...THE 00Z GFS AND ECMWF ARE QUITE CLOSE WITH THE TIMING
AND STRENGTH OF A SIGNIFICANT SHORTWAVE TROUGH AMPLIFYING IN THE
LEE OF THE CANADIAN ROCKIES ON DAY 5/SUN WITH AN ACCOMPANYING COLD
FRONTAL PASSAGE...AND ON DAY 6/MON WITH A SECONDARY SHORTWAVE
TROUGH BEGINNING TO INFLUENCE THE PACIFIC NORTHWEST.

WILL GREATLY REFINE THE INTERACTION BETWEEN IRENE AND THE MAIN
BAND OF WESTERLIES WITH THE ADVENT OF THE 15Z/23 NHC FORECAST AND
THE 17Z/23 COORDINATION CALL FOR THE FINAL ISSUANCE THIS

AFTERNOON.

...AFTERNOON FINALS...

PROG PRODUCTION AND PMDEPD INTERUPTED BY EAST COAST EARTHQUAKE AND
BUILDING EVACUATION.IRENE TRACK ADJUSTED TO LATEST NHC GUIDANCE/FORECAST. LATEST AFTN GLOBAL MODEL BEGINNING TO CONVERGE ON SOLUTION TRACK WITH RIGHT MODELS CMC/GFS COMING LEFT AND ECMWF/UKMET COMING RIGHT. NHC TRACK SHIFTED EASTWARD. AT THIS TIME THIS HAS ALL THE LOOK OF A VERY DEEP DANGEROUS HURRICANE WITH TRACK AND POSSIBLE INTENSITY TO THAT OF THE GREAT HURRICANE OF 1944. SEE NHC
FORECAST/WATCHS/WARNINGS ALONG WITH NWS LOCAL OFFICE

WARNINGS/STATEMENTS.

K JAMES/J CISCO/ F ROSENSTEIN