By John Galt
July 18, 2011
******* If it moves further out to see with no indication of moving towards the North, coverage will cease at 1700 tomorrow if it is no threat to the U.S. *******
Tropical Storm Bret, Public Advisory 5 1700 EDT:
000
WTNT32 KNHC 182056
TCPAT2
BULLETIN
TROPICAL STORM BRET ADVISORY NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL022011
500 PM EDT MON JUL 18 2011
…BRET STRENGTHENS AS IT HEADS AWAY FROM THE BAHAMAS…
SUMMARY OF 500 PM EDT…2100 UTC…INFORMATION
———————————————-
LOCATION…28.3N 77.0W
ABOUT 130 MI…210 KM N OF GREAT ABACO ISLAND
MAXIMUM SUSTAINED WINDS…65 MPH…100 KM/H
PRESENT MOVEMENT…NNE OR 30 DEGREES AT 7 MPH…11 KM/H
MINIMUM CENTRAL PRESSURE…996 MB…29.41 INCHES
WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY…
THE GOVERNMENT OF THE BAHAMAS HAS DISCONTINUED THE TROPICAL STORM
WARNINGS FOR GRAND BAHAMA ISLAND AND THE ABACO ISLANDS.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT…
NONE.
DISCUSSION AND 48-HOUR OUTLOOK
——————————
AT 500 PM EDT…2100 UTC…THE CENTER OF TROPICAL STORM BRET WAS
LOCATED NEAR LATITUDE 28.3 NORTH…LONGITUDE 77.0 WEST. BRET IS
MOVING TOWARD THE NORTH-NORTHEAST NEAR 7 MPH…11 KM/H…AND A TURN
TOWARD THE NORTHEAST WITH AN INCREASE IN FORWARD SPEED IS EXPECTED
OVER THE NEXT 48 HOURS.
OBSERVATIONS FROM AN AIR FORCE RESERVE UNIT HURRICANE HUNTER
AIRCRAFT INDICATE THAT THE MAXIMUM SUSTAINED WINDS HAVE INCREASED
TO NEAR 65 MPH…100 KM/H…WITH HIGHER GUSTS. SOME ADDITIONAL
STRENGTHENING IS POSSIBLE OVERNIGHT…AND BRET COULD APPROACH
HURRICANE STRENGTH BY EARLY TUESDAY.
TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 50 MILES…85 KM
FROM THE CENTER.
THE MINIMUM CENTRAL PRESSURE ESTIMATED FROM HURRICANE HUNTER DATA IS
996 MB…29.41 INCHES.
HAZARDS AFFECTING LAND
———————-
RAINFALL…BRET COULD PRODUCE TOTAL RAINFALL AMOUNTS OF 2 TO 4
INCHES OVER THE NORTHWEST BAHAMAS. THESE RAINS WILL DIMINISH
TONIGHT.
SURF…LOCALLY HIGH SURF CONDITIONS ALONG THE NORTHERN AND WESTERN
FACING BEACHES IN THE NORTHWEST BAHAMAS WILL DECREASE TONIGHT.
NEXT ADVISORY
————-
NEXT COMPLETE ADVISORY…1100 PM EDT.
$$
FORECASTER PASCH
TROPICAL STORM BRET FORECAST DISCUSSION#3:
000
WTNT42 KNHC 180853
TCDAT2
TROPICAL STORM BRET DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL022011
500 AM EDT MON JUL 18 2011
THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING BRET
OVERNIGHT FOUND THAT THE CYCLONE HAS CONTINUED TO SLOWLY STRENGTHEN
…WITH THE CENTRAL PRESSURE FALLING TO 1001 MB. THE INITIAL
INTENSITY IS RAISED TO 45 KT BASED ON A PEAK 850-MB FLIGHT-LEVEL
WIND OF 54 KT AND SOME BELIEVABLE 45 TO 50 KT SFMR WINDS OUTSIDE
AREAS OF HEAVY RAIN AND SHALLOW WATERS NEAR THE ABACOS ISLANDS.
SATELLITE AND RADAR IMAGERY SHOW THAT DEEP CONVECTION HAS INCREASED
NEAR THE CENTER AND IN A PROMINENT BAND IN THE EASTERN SEMICIRCLE
OVER THE PAST FEW HOURS…HOWEVER DRY AIR IS STILL IMPINGING ON THE
WESTERN HALF OF THE CIRCULATION. ALSO…AN UPPER-LEVEL SHEAR AXIS
SITUATED JUST NORTHWEST OF BRET APPEARS TO BE HINDERING OUTFLOW IN
THE WESTERN SEMICIRCLE AND THE AIRCRAFT NOTED A 3 TO 5 NM
SOUTHEASTWARD TILT BETWEEN THE SURFACE AND 850-MB CENTERS. THE
INTENSITY GUIDANCE IS CONSISTENT WITH THIS MARGINAL ENVIRONMENT AND
SUGGESTS THAT BRET HAS A PERIOD OF 24 TO 36 HOURS TO STEADILY
STRENGTHEN BEFORE THE SHEAR INCREASES MARKEDLY AND THE CYCLONE
BEGINS TO MOVE OVER COOLER WATERS. THE OFFICIAL FORECAST HAS BEEN
NUDGED UPWARD IN AGREEMENT WITH THE SHIPS MODEL THROUGH 48 HOURS
AND A BLEND OF THE SHIPS AND LGEM BEYOND THAT TIME.
BRET JOGGED SOUTH-SOUTHEASTWARD OVERNIGHT…ALTHOUGH THE LATEST
AIRCRAFT FIXES AND DOPPLER RADAR IMAGERY FROM MIAMI SUGGEST THAT THE
CYCLONE HAS TURNED TOWARD THE EAST IN THE PAST COUPLE OF HOURS…
POSSIBLY COMPLETING A CYCLONIC LOOP. THE LATEST AIRCRAFT FIXES
YIELD AN INITIAL MOTION ESTIMATE OF 090/03 KT. ALL OF THE GUIDANCE
INSISTS THAT BRET WILL BEGIN TO MOVE SLOWLY NORTH-NORTHEASTWARD BY
TONIGHT AS THE CYCLONE COMES UNDER THE INFLUENCE OF A BUILDING
MID-LEVEL RIDGE TO ITS SOUTHEAST. BY 48 HOURS AND BEYOND THE
GLOBAL MODELS SUGGEST THAT A BROAD MID-LEVEL TROUGH OFFSHORE OF THE
NORTHEASTERN U.S. WILL DEEPEN ENOUGH TO CAPTURE BRET AND ACCELERATE
THE CYCLONE INTO THE WESTERLIES BY THE END OF THE PERIOD. GIVEN
THE EASTWARD MOVEMENT OF THE CYCLONE OVERNIGHT AND A GENERAL
WESTWARD TREND IN THE GUIDANCE ENVELOPE…THE NEW OFFICIAL FORECAST
IS SIMILAR TO THE PREVIOUS ONE THROUGH 48 HOURS AND LIES CLOSE TO A
BLEND OF THE ECMWF…UKMET…GFS…GFDL…AND HWRF MODELS. AFTER
THAT TIME…THE NHC FORECAST IS ADJUSTED TOWARD THIS MODEL BLEND
AND IS LEFT OF AND A LITTLE SLOWER THAN THE PREVIOUS PACKAGE.
FURTHER ADJUSTMENTS IN THIS DIRECTION MAY BE NECESSARY NEAR THE END
OF THE PERIOD IF THIS TREND IN THE GUIDANCE CONTINUES.
FORECAST POSITIONS AND MAX WINDS
INIT 18/0900Z 27.2N 77.7W 45 KT 50 MPH
12H 18/1800Z 27.6N 77.7W 50 KT 60 MPH
24H 19/0600Z 28.6N 77.2W 55 KT 65 MPH
36H 19/1800Z 29.7N 76.5W 55 KT 65 MPH
48H 20/0600Z 30.7N 75.4W 50 KT 60 MPH
72H 21/0600Z 32.5N 71.5W 45 KT 50 MPH
96H 22/0600Z 35.0N 67.0W 35 KT 40 MPH
120H 23/0600Z 38.0N 59.0W 30 KT 35 MPH
$$
FORECASTER BRENNAN
TROPICAL STORM BRET FORECAST TRACK
Images Refresh automatically from the NHC:
INVEST 98L
INVEST 98L
Stay tuned for further updates....
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