Hurricane Irene A Potentially Historic Storm No.2

WTNT34 KNHC 260254
TCPAT4
BULLETIN
HURRICANE IRENE ADVISORY NUMBER 23
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 PM EDT THU AUG 25 2011

...HURRICANE IRENE AIMS ITS FURY TOWARD THE NORTH CAROLINA COAST...AT 1100 PM EDT...0300 UTC...THE CENTER OF HURRICANE IRENE WAS

LOCATED NEAR LATITUDE 28.3 NORTH...LONGITUDE 77.3 WEST. IRENE IS
MOVING TOWARD THE NORTH NEAR 14 MPH...22 KM/H...AND THIS MOTION IS
EXPECTED TO CONTINUE DURING THE NEXT 24 HOURS. A GRADUAL TURN TOWARD
THE NORTH-NORTHEAST SHOULD BEGIN THEREAFTER. ON THE FORECAST
TRACK...IRENE WILL CONTINUE TO MOVE AWAY FROM THE NORTHWESTERN
BAHAMAS...AND THE CORE OF THE HURRICANE WILL PASS WELL OFFSHORE OF
THE EAST COAST OF CENTRAL AND NORTHERN FLORIDA EARLY FRIDAY. THE
HURRICANE IS FORECAST TO APPROACH THE COAST OF NORTH CAROLINA ON
SATURDAY.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 115 MPH...185 KM/H...WITH HIGHER
GUSTS. IRENE IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME STRENGTHENING IS POSSIBLE ON FRIDAY.

IRENE IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND
OUTWARD UP TO 80 MILES...130 KM...FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 290 MILES...465 KM. NOAA
BUOY 41010 LOCATED ABOUT 140 MILES...220 KM EAST OF CAPE CANAVERAL
FLORIDA RECENTLY REPORTED A SUSTAINED WIND OF 49 MPH...79 KM/H...
AND A WIND GUST OF 65 MPH...104 KM/H.

THE MINIMUM CENTRAL PRESSURE RECENTLY REPORTED BY A NOAA HURRICANE
HUNTER AIRCRAFT WAS 942 MB...27.82 INCHES.

000

FXUS61 KCAR 260257
AFDCAR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
1057 PM EDT THU AUG 25 2011
.SYNOPSIS...

-- Changed Discussion --A COLD FRONT WILL CROSS THE REGION OVERNIGHT. HIGH PRESSURE WILL
BUILD ACROSS THE REGION FRIDAY. HURRICANE IRENE WILL MOVE
NORTHWARD ALONG THE EASTERN SEABOARD OVER THE WEEKEND.-- End Changed Discussion --
&&

.NEAR TERM /THROUGH FRIDAY/...

-- Changed Discussion --UPDATE...

A COLD FRONT WILL CROSS THE REGION OVERNIGHT. SHOWERS AND
THUNDERSTORMS WILL OCCUR IN ADVANCE OF THE FRONT.
SHOWERS/THUNDERSTORMS WILL END IN THE WAKE OF THE COLD FRONT WITH
DECREASING CLOUDS LATE. HAVE UPDATED THE FORECAST TO ADJUST FOR
CURRENT CONDITIONS...ALONG WITH EXPECTED OVERNIGHT
SHOWER/THUNDERSTORM CHANCES AND CLOUD COVER. OVERNIGHT LOW
TEMPERATURES ARE EXPECTED TO RANGE FROM THE MID TO UPPER 50S
NORTH...TO AROUND 60 TO THE LOWER 60S DOWNEAST.

PREVIOUS DISCUSSION...

LOOKS LIKE WE WILL SEE PLENTY OF SUNSHINE ON FRIDAY WITH HIGH
PRESSURE RIDGING ACROSS THE REGION. HIGH TEMPERATURES FRIDAY ARE
EXPECTED TO RANGE FROM THE MID TO UPPER 70S NORTH...TO THE UPPER
70S TO AROUND 80 INTERIOR DOWNEAST WITH MID TO UPPER 70S ALONG
THE DOWNEAST COAST.-- End Changed Discussion --
&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
STRONG HIGH PRESSURE CENTER OFF THE EAST COAST AT THE BEGINNING
OF THIS FORECAST PERIOD. AT THE SAME TIME HURRICANE IRENE WILL BE
APPROACHING THE CAROLINA COAST. IN ADDITION A COLD FRONT AND UPPER
TROUGH WILL BE MOVING INTO THE GREAT LAKES. HURRICANE IRENE WILL
MOVE TO A POSITION NEAR THE NORTH CAROLINA COAST SATURDAY MORNING
THEN MOVE NORTHWARD ALONG THE MID ATLANTIC COAST LATE SATURDAY AND
DURING THE DAY SUNDAY. AT THIS TIME IT IS UNCERTAIN IF IRENE WILL
MOVE NORTHWARD ON THE MID ATLANTIC COAST OR MOVE SOME DISTANCE
OFF-SHORE. THIS WILL HAVE AN EFFECT ON THE INTENSITY OF THE
HURRICANE WHEN IT REACHES NEW ENGLAND WITH THE LATER OPTION
RESULTING IN THE GREATEST INTENSITY. THE SYSTEM IS THEN EXPECTED
TO MOVE EITHER ALONG THE MAINE COAST OR ACROSS INLAND MAINE LATER
SUNDAY NIGHT. IRENE WILL THEN MOVE NORTHWARD INTO CANADA BY MID
MORNING MONDAY. HAVE INITIALIZED THE WIND GRIDS WITH A BLEND OF
THE NAM12 AND GMOS THROUGH 1000Z SUNDAY THEN TRANSITION TO THE TCM
WIND GRIDS OVERLAID ON THE GFS40. WILL HAND EDIT THE TCM WIND
GRIDS TO BETTER MESS WITH THE GFS40. FOR POP GRIDS HAVE USED THE
GFS40. FOR TEMPERATURE AND DEW POINT WILL USE THE GMOS. THE QPF
GRIDS GENERATED WITH A BLEND OF THE NAM12 AND GFS40.
&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
ANY LINGERING RAIN AND WIND FROM IRENE WILL QUICKLY DIMINISH MONDAY
EVENING AS THE STORM PULLS AWAY. FOLLOWING THE PASSAGE OF THE
STORM HIGH PRESSURE WILL BUILD IN MONDAY NIGHT BRINGING FAIR
WEATHER WITH DIMINISHING WINDS. TUESDAY WILL BEGIN MAINLY SUNNY
HOWEVER A WEAK DISTURBANCE WILL APPROACH IN THE AFTERNOON AND
COULD TOUCH OFF A FEW ISOLATED SHOWERS, MAINLY OVER NORTHERN AND
WESTERN AREAS. BEYOND THIS TIME HIGH PRESSURE WILL REESTABLISH
ITSELF OVER THE FORECAST AREA BRINGING MAINLY SUNNY SKIES ALONG
WITH SEASONAL TEMPERATURES FOR THE MIDDLE TO LATTER PART OF NEXT
WEEK.
&&

EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
235 PM EDT THU AUG 25 2011
VALID 12Z SUN AUG 28 2011 - 12Z THU SEP 01 2011

...MAJOR HURRICANE IRENE TO STRONGLY AFFECT THE EAST COAST FROM NC
INTO THE NEW ENGLAND THIS WEEKEND...

THE LATEST NUMERICAL GUIDANCE CONTINUES TO ADJUST WESTWARD AS HAS
THE LAST SEVERAL NHC TRACK FORECASTS WHICH NOW HAVE EYE OF IRENE
COMING THRU THE NORTH CAROLINA LOWER OUTER BANKS LATE SATURDAY
BEFORE GRAZING THE DELMARVA AND NEW JERSEY THEN MOVING INTO THE
NORTHEAST ON SUNDAY. THIS POTENTIALLY COULD BE EXTREMELY
DESTRUCTIVE WITH MASSIVE DISRUPTIONS TO SOCIETY AND COMMERCE ALONG
ITS ENTIRE TRACK WITH VERY HIGH WINDS/STORM SURGE/OCEAN
OVERWASH/BEACH EROSION/SOUND AND BAY SIDE COASTAL FLOODING AND
EXTREME TIDE POTENTIAL. WIDESPREAD HEAVY RAINS IN THE 6-10 INCH
RANGE WILL BE COMMON WITH GREATLY INCREASED INLAND FLOOD
POTENTIAL. REFER TO THE NHC FOR THE LATEST FORECAST OF IRENE ALONG
WITH LOCAL NWS WARNINGS/STATEMENTS AND ADVISORIES FROM NC INTO NEW
ENGLAND.

ON A LARGER SCALE...SUBTLE RUN-TO-RUN VARIANCES IN THE TIMING AND
STRENGTH OF A COMPLICATED SHORTWAVE TROUGH CURRENTLY EVOLVING OFF
THE PACIFIC NORTHWEST APPEARS TO PLAY A PIVOTAL ROLE IN THE PATH
OF IRENE DURING THE EARLY STAGES OF THE MEDIUM RANGE PERIOD. THE
00Z GFS IS NOTICEABLY FASTER AND LESS AMPLIFIED WITH THIS TROUGH
AS IT REACHES THE MIDWEST ON DAY 3 WHILE THE 00Z ECMWF IS SLOWER
AND MORE AMPLIFIED AS IS ITS ENSEMBLE MEAN THE 00Z UKMET/CANADIAN
OFFER INTERMEDIATE SOLUTIONS...WHICH IS A PRUDENT PLACE TO LIE
UNTIL THE TROUGH MOVES INLAND AND CAN BECOME BETTER SAMPLED BY THE
MORE DENSE OBSERVATIONAL NETWORK FOR ASSIMILATION INTO THE MODELS.
UNTIL THEN...SUBTLE RUN-TO-RUN DIFFERENCES ARE LIKELY TO CONTINUE.
THIS DIGGING TROF SEEMS TO BE THE MAIN REASON FOR THE ECMWFS MORE
WESTWARD TRACK OVER THE PAST 2 CYCLES OF HURRICANE IRENE AND NEEDS
TO BE CLOSELY WATCHED AS WE GO INTO THE SHORTER RANGE.
AGAIN...REFER TO THE NHC FOR THE LATEST FORECAST OF IRENE.....

....JAMES/ROSENSTEIN