EPAC: TROPICAL DEPRESSION BLAS - DISCUSSION

[KWT]

Pretty easy forecast really, strengthening probably going to slowly continue over the next 12-18hrs then probably levelling off as conditions start to become worse aloft.

[cycloneye]

TROPICAL STORM BLAS DISCUSSION NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
800 PM PDT THU JUN 17 2010

BLAS HAS CHANGED LITTLE IN ORGANIZATION OVER THE LAST SEVERAL HOURS
WITH BANDING FEATURES CONFINED TO THE WESTERN SEMICIRCLE OF THE
STORM...ALTHOUGH THERE HAS BEEN A RECENT BURST OF DEEP CONVECTION
NEAR THE CENTER. THE INITIAL INTENSITY IS HELD AT 40 KT...
CONSISTENT WITH A BLEND OF THE TAFB AND SAB DVORAK INTENSITY
ESTIMATES. ONLY A LITTLE STRENGTHENING OF BLAS IS FORECAST IN THE
SHORT-TERM AS MODERATE EASTERLY SHEAR IS EXPECTED TO CONTINUE TO
IMPACT THE SYSTEM DURING THE NEXT 24 HOURS. BEYOND THAT TIME...THE
CYCLONE IS EXPECTED TO MOVE OVER COOLER SEA SURFACE TEMPERATURES
AND INTO A MORE STABLE ENVIRONMENT...WHICH SHOULD CAUSE WEAKENING.
THE OFFICIAL INTENSITY FORECAST IS UNCHANGED FROM THE PREVIOUS ONE
AND REMAINS IN GOOD AGREEMENT WITH THE INTENSITY MODEL CONSENSUS.

BLAS APPEARS TO HAVE INCREASED SLIGHTLY IN FORWARD SPEED...BASED ON
GEOSTATIONARY SATELLITE FIXES AND VERY HELPFUL AMSR-E AND TRMM
PASSES...AND THE INITIAL MOTION ESTIMATE IS 300/4. GLOBAL MODELS
SHOW MID-LEVEL RIDGING OVER MEXICO BUILDING WESTWARD OVER THE NEXT
COUPLE OF DAYS...WHICH SHOULD ALLOW BLAS TO CONTINUE MOVING
WEST-NORTHWESTWARD DURING THE NEXT 48 HOURS OR SO. A TURN TOWARD
THE WEST IS FORECAST LATER IN THE PERIOD AS BLAS BECOMES A SHALLOW
SYSTEM AND IS STEERED MAINLY BY THE LOW-LEVEL FLOW. THE NEW NHC
TRACK FORECAST IS NUDGED ONLY SLIGHTLY TO THE NORTH...TRENDING
TOWARD THE VARIABLE TRACK MODEL CONSENSUS...TVCN.

FORECAST POSITIONS AND MAX WINDS

INITIAL 18/0300Z 15.5N 106.4W 40 KT
12HR VT 18/1200Z 15.8N 106.9W 45 KT
24HR VT 19/0000Z 16.0N 107.7W 45 KT
36HR VT 19/1200Z 16.3N 108.7W 40 KT
48HR VT 20/0000Z 16.7N 109.9W 40 KT
72HR VT 21/0000Z 17.0N 113.0W 35 KT
96HR VT 22/0000Z 17.0N 116.0W 25 KT
120HR VT 23/0000Z 16.5N 120.5W 20 KT...POST-TROP/REMNT LOW

$$
FORECASTER CANGIALOSI/PASCH

[cycloneye]

141
WTPZ43 KNHC 181433
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
800 AM PDT FRI JUN 18 2010

FIRST-LIGHT VISIBLE IMAGERY SHOWS BLAS HAS BECOME A LITTLE BETTER
ORGANIZED...WITH THE LOW-LEVEL CENTER NEAR OR EMBEDDED IN THE
NORTHERN SIDE OF THE CENTRAL CONVECTION. SATELLITE INTENSITY
ESTIMATES ARE 45 KT FROM TAFB AND 35 KT FROM SAB. BASED ON
THIS...THE INITIAL INTENSITY IS INCREASED TO 40 KT. THE STORM
CONTINUES TO EXPERIENCE MODERATE NORTHEASTERLY VERTICAL WIND
SHEAR...WITH POOR TO FAIR CIRRUS OUTFLOW IN THE SOUTHWESTERN
SEMICIRCLE AND NONE ELSEWHERE.

WHILE THE LARGE-SCALE MODELS FORECAST THE SHEAR TO DECREASE DURING
THE NEXT 48-72 HR...THE FORECAST TRACK TAKES BLAS OVER STEADILY
DECREASING SEA SURFACE TEMPERATURES. THIS SHOULD CAUSE THE STORM
TO SLOWLY WEAKEN...WITH THE INTENSITY FORECAST CALLING FOR IT TO
BECOME A TROPICAL DEPRESSION IN ABOUT 48 HR AND A REMNANT LOW IN
ABOUT 96 HR. THE NEW INTENSITY FORECAST IS IN BEST AGREEMENT WITH
THE INTENSITY CONSENSUS.

THE INITIAL MOTION IS 300/5. BLAS IS ON THE SOUTH SIDE OF A
MID-LEVEL RIDGE EXTENDING WESTWARD FROM MEXICO...AND THE
LARGE-SCALE MODELS FORECAST THIS FEATURE TO PERSIST WITH LITTLE
CHANGE IN STRENGTH THROUGH THE FORECAST PERIOD...WITH A LOW-LEVEL
RIDGE BUILDING NORTH AND WEST OF THE CYCLONE AFTER 72 HR. THE
TRACK GUIDANCE RESPONDS TO THIS BY SHOWING THE CURRENT WEST-
NORTHWESTWARD MOTION BECOMING WESTWARD DURING THE NEXT COUPLE OF
DAYS...AND WEST-SOUTHWESTWARD AFTER 72 HR. THE NEW FORECAST TRACK
IS A LITTLE SOUTH OF AND FASTER THAN THE PREVIOUS TRACK...AND IT
LIES A LITTLE TO THE NORTH OF THE MODEL CONSENSUS AND THE GLOBAL
MODEL FORECASTS.


FORECAST POSITIONS AND MAX WINDS

INITIAL 18/1500Z 16.0N 107.4W 40 KT
12HR VT 19/0000Z 16.3N 108.3W 40 KT
24HR VT 19/1200Z 16.6N 109.7W 35 KT
36HR VT 20/0000Z 16.8N 111.1W 35 KT
48HR VT 20/1200Z 16.9N 112.8W 30 KT
72HR VT 21/1200Z 17.0N 116.0W 25 KT
96HR VT 22/1200Z 16.5N 119.0W 25 KT...POST-TROP/REMNT LOW
120HR VT 23/1200Z 16.0N 122.0W 20 KT...POST-TROP/REMNT LOW

$$
FORECASTER BEVEN

[KWT]

So it looks like Blas has peaked out now then according to the NHC at 40kts.

[cycloneye]

WTPZ43 KNHC 182034
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
200 PM PDT FRI JUN 18 2010

VISIBLE IMAGERY SHOWS THAT THE LOW-LEVEL CENTER OF BLAS IS LOCATED
AT THE NORTHEASTERN EDGE OF THE MAIN CONVECTIVE REGION. A RECENT
ASCAT SCATTEROMETER OVERPASS SHOWS 35-40 KT WINDS SOUTH OF THE
CENTER...SO THE INITIAL INTENSITY REMAINS 40 KT. THE STORM
CONTINUES TO EXPERIENCE LIGHT/MODERATE NORTHEASTERLY VERTICAL WIND
SHEAR...WITH FAIR CIRRUS OUTFLOW IN THE SOUTHWESTERN SEMICIRCLE AND
POOR/NONE ELSEWHERE.

THE LARGE-SCALE MODELS STILL FORECAST THE SHEAR TO DECREASE DURING
THE NEXT 48-72 HR. HOWEVER...THE FORECAST TRACK TAKES BLAS OVER
STEADILY DECREASING SEA SURFACE TEMPERATURES. THE LATTER SHOULD
CAUSE THE STORM TO SLOWLY WEAKEN...WITH THE INTENSITY FORECAST
CALLING FOR BLAS TO BECOME A TROPICAL DEPRESSION IN ABOUT 48 HR AND
A REMNANT LOW IN ABOUT 96 HR. THE NEW INTENSITY FORECAST IS IN
BEST AGREEMENT WITH...ALTHOUGH A LITTLE BELOW...THE INTENSITY
CONSENSUS.

THE INITIAL MOTION IS NOW 290/5. BLAS REMAINS ON THE SOUTH SIDE OF
A MID-LEVEL RIDGE EXTENDING WESTWARD FROM MEXICO...AND THE
LARGE-SCALE MODELS FORECAST THIS FEATURE TO PERSIST WITH LITTLE
CHANGE IN STRENGTH THROUGH THE FORECAST PERIOD. A LOW-LEVEL RIDGE
IS FORECAST TO BUILD NORTH AND WEST OF THE CYCLONE AFTER 72 HR.
THE TRACK GUIDANCE RESPONDS TO THIS BY SHOWING THE CURRENT WEST-
NORTHWESTWARD MOTION BECOMING WESTWARD DURING THE NEXT COUPLE OF
DAYS...AND WEST-SOUTHWESTWARD AT ABOUT 72 HR. THE NEW FORECAST
TRACK IS SIMILAR TO THE PREVIOUS TRACK. HOWEVER...THE GUIDANCE
ENVELOPE HAS SHIFTED A LITTLE TO THE NORTH SINCE THE LAST
PACKAGE...AND THE FORECAST TRACK NOW LIES ALONG OR JUST SOUTH OF
THE MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 18/2100Z 16.1N 108.0W 40 KT
12HR VT 19/0600Z 16.3N 108.8W 40 KT
24HR VT 19/1800Z 16.6N 110.2W 35 KT
36HR VT 20/0600Z 16.8N 111.9W 35 KT
48HR VT 20/1800Z 16.9N 113.6W 30 KT
72HR VT 21/1800Z 17.0N 117.0W 25 KT
96HR VT 22/1800Z 16.5N 120.0W 25 KT...POST-TROP/REMNT LOW
120HR VT 23/1800Z 16.0N 123.5W 20 KT...POST-TROP/REMNT LOW

$$
FORECASTER BEVEN

[clfenwi]

Nice convective bursts in the past few hours caused intensity to be nudged up.

EP, 03, 2010061900, , BEST, 0, 162N, 1082W, 45, 997, TS

[clfenwi]

WTPZ43 KNHC 190233
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
800 PM PDT FRI JUN 18 2010

SATELLITE IMAGERY INDICATES THAT DEEP CONVECTION ASSOCIATED WITH
BLAS HAS INCREASED IN COVERAGE AND INTENSITY IN THE LAST FEW HOURS.
DVORAK INTENSITY ESTIMATES HAVE INCREASED TO 3.0/45 KT FROM BOTH
TAFB AND SAB AND ON THIS BASIS...THE INITIAL INTENSITY IS RAISED TO
45 KT. THE LOW-LEVEL CENTER REMAINS NEAR THE NORTHEASTERN EDGE OF
THE CONVECTIVE MASS...INDICATIVE OF CONTINUED NORTHEASTERLY
VERTICAL WIND SHEAR AS ANALYZED BY THE SHIPS MODEL AND UW-CIMSS.
WHILE THE SHIPS MODEL SHOWS THE SHEAR DECREASING DURING THE NEXT
COUPLE OF DAYS...BLAS IS EXPECTED TO MOVE OVER COOLER WATER AND
INTO A MORE STABLE ATMOSPHERE...AND THE LESS FAVORABLE
THERMODYNAMIC ENVIRONMENT SHOULD RESULT IN WEAKENING. THE NEW
INTENSITY FORECAST IS NUDGED UPWARD THROUGH 48 HOURS TO ACCOUNT FOR
THE CURRENT STRENGTHENING...AND BEYOND THAT TIME IS NEAR THE
PREVIOUS ADVISORY...IN BEST AGREEMENT WITH THE LGEM MODEL.

GEOSTATIONARY AND MICROWAVE SATELLITE FIXES YIELD AN INITIAL MOTION
ESTIMATE OF 285/6. THE GLOBAL MODELS SHOW MID-LEVEL RIDGING
REMAINING NORTH OF THE CYCLONE FOR THE NEXT SEVERAL DAYS. THIS
PATTERN SHOULD KEEP BLAS ON A WEST TO WEST-NORTHWESTWARD PATH OVER
THE NEXT 36-48 HOURS. BEYOND THAT TIME...BLAS IS EXPECTED TO BECOME
A SHALLOW SYSTEM AND TURN TOWARD THE WEST-SOUTHWEST UNDER THE
INFLUENCE OF THE LOW-LEVEL FLOW. THE NEW TRACK FORECAST IS
BASICALLY AN UPDATE OF THE PREVIOUS ONE AND IS NEAR THE MULTI-MODEL
TVCN CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 19/0300Z 16.3N 108.5W 45 KT
12HR VT 19/1200Z 16.5N 109.5W 45 KT
24HR VT 20/0000Z 16.8N 111.2W 40 KT
36HR VT 20/1200Z 17.0N 112.8W 40 KT
48HR VT 21/0000Z 17.0N 114.6W 35 KT
72HR VT 22/0000Z 17.0N 118.0W 30 KT
96HR VT 23/0000Z 16.5N 121.0W 25 KT...POST-TROP/REMNT LOW
120HR VT 24/0000Z 16.0N 124.5W 20 KT...POST-TROP/REMNT LOW

[cycloneye]

TROPICAL STORM BLAS DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
200 AM PDT SAT JUN 19 2010

INFRARED SATELLITE IMAGERY INDICATES THAT BLAS HAS MAINTAINED A
LARGE AREA OF COLD CONVECTIVE TOPS DURING THE PAST SEVERAL HOURS.
HOWEVER...THE CONVECTIVE PATTERN...WITH A SHARP EASTERN EDGE...
APPEARS SOMEWHAT AMORPHOUS AND RESEMBLES THAT OF A SHEARED TROPICAL
CYCLONE. A 0451 UTC TRMM PASS CONFIRMS THAT BLAS CONTINUES TO SUFFER
FROM THE EFFECTS OF NORTHEASTERLY SHEAR...WITH THE LOW-LEVEL CENTER
STILL ON THE NORTHEASTERN EDGE OF THE DEEPEST CONVECTIVE CLOUDS.
GIVEN THAT THERE HAS BEEN NO FURTHER INCREASE IN ORGANIZATION AND
THE TAFB DVORAK INTENSITY ESTIMATE REMAINS AT 3.0/45 KT...THE
INITIAL INTENSITY IS UNCHANGED AT 45 KT.

CONVENTIONAL AND MICROWAVE SATELLITE CENTER FIXES YIELD AN INITIAL
MOTION ESTIMATE OF 285/6. GLOBAL MODELS SHOW A STRONG DEEP LAYER
RIDGE EXTENDING WEST-SOUTHWESTWARD FROM THE SOUTH CENTRAL UNITED
STATES INTO THE TROPICAL EAST PACIFIC WHICH SHOULD STEER BLAS ON A
GENERAL WESTWARD TO WEST-NORTHWESTWARD COURSE THROUGH 36-48
HOURS...WITH A MINOR INCREASE IN FORWARD SPEED. THEREAFTER...BLAS
IS EXPECTED TO BECOME A SHALLOW SYSTEM AND TURN WEST-SOUTHWESTWARD
IN THE LOW-LEVEL FLOW. THE NEW TRACK FORECAST REPRESENTS A BLEND
OF THE PREVIOUS OFFICIAL TRACK AND THE MULTI-MODEL TVCN CONSENSUS.

THE SHIPS MODEL AND UW-CIMSS VERTICAL WIND SHEAR ANALYSES CONTINUE
TO ANALYZE MODERATE NORTHEASTERLY SHEAR OVER THE CYCLONE. HOWEVER...
THE SHIPS MODEL STILL INDICATES A REDUCTION IN THE VERTICAL SHEAR
OVER THE NEXT COUPLE OF DAYS...POSSIBLY A RESULT OF BLAS MOVING OUT
OF THE MONSOONAL ENVIRONMENT IN WHICH IT HAS BEEN EMBEDDED AND INTO
ONE WITH A DEEP LAYER OF EASTERLIES. HOWEVER...BEYOND 24 HOURS BLAS
IS EXPECTED TO REACH COOLER WATER AND ENCOUNTER A MORE STABLE
ATMOSPHERE...THE COMBINATION OF WHICH SHOULD LEAD TO WEAKENING. THE
OFFICIAL INTENSITY FORECAST REPRESENTS AN UPDATE OF THE PREVIOUS
ONE...WITH THE FORECAST CLOSELY FOLLOWING THE LGEM INTENSITY
GUIDANCE.


FORECAST POSITIONS AND MAX WINDS

INITIAL 19/0900Z 16.4N 109.1W 45 KT
12HR VT 19/1800Z 16.7N 110.4W 45 KT
24HR VT 20/0600Z 16.9N 112.1W 40 KT
36HR VT 20/1800Z 17.0N 114.0W 40 KT
48HR VT 21/0600Z 17.1N 115.9W 35 KT
72HR VT 22/0600Z 16.9N 119.5W 30 KT
96HR VT 23/0600Z 16.5N 123.0W 25 KT...POST-TROP/REMNT LOW
120HR VT 24/0600Z 16.0N 126.5W 20 KT...POST-TROP/REMNT LOW

$$
FORECASTER KIMBERLAIN

[cycloneye]

12 UTC Best Track

Intensity increased to 55kts.

EP, 03, 2010061912, , BEST, 0, 165N, 1094W, 55, 992, TS

[cycloneye]

WTPZ43 KNHC 191437
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
800 AM PDT SAT JUN 19 2010

EARLY MORNING VISIBLE SATELLITE IMAGERY SUGGESTS THAT THE CENTER OF
BLAS IS LOCATED JUST TO THE EAST-NORTHEAST OF THE DEEPEST
CONVECTION. THIS IS CONSISTENT WITH THE MORE EASTERLY SHEAR
ANALYZED OVER THE CYCLONE BY UW-CIMSS. WITH THE CENTER EMBEDDED
CLOSER TO THE CONVECTION...DVORAK INTENSITY ESTIMATES HAVE
INCREASED TO 55 KT FROM TAFB AND SAB...AND THAT IS THE INITIAL
INTENSITY FOR THIS ADVISORY.

WITH A LACK OF MICROWAVE IMAGERY OVER THE PAST SEVERAL HOURS THE
INITIAL MOTION ESTIMATE IS A RATHER UNCERTAIN 280/06. WHILE THE
INITIAL POSITION IS A LITTLE SOUTH OF THE PREVIOUS FORECAST...THE
OVERALL TRACK FORECAST REASONING REMAINS UNCHANGED. BLAS WILL
CONTINUE MOVING GENERALLY WESTWARD TO THE SOUTH OF A DEEP-LAYER
RIDGE OVER THE EASTERN PACIFIC FOR THE NEXT COUPLE OF DAYS WITH A
SLIGHT INCREASE IN FORWARD SPEED. BY 72 HOURS AND BEYOND...A MOTION
SOUTH OF DUE WEST IS EXPECTED AS THE WEAKENING CYCLONE IS
INCREASINGLY STEERED BY THE LOW-LEVEL FLOW. THE NEW TRACK FORECAST
IS ADJUSTED SOUTHWARD FROM THE PREVIOUS PACKAGE DUE TO THE MORE
SOUTHERLY INITIAL POSITION...BUT LIES CLOSE TO THE MIDDLE OF THE
GUIDANCE ENVELOPE.

THE INTENSITY FORECAST HAS BEEN ADJUSTED UPWARD TO ACCOUNT FOR THE
OBSERVED INTENSITY TRENDS...AND SHOWS A PEAK AT 12 HOURS IN
AGREEMENT WITH THE SHIPS...LGEM...HWRF...AND GFDL. WHILE NONE OF
THE GUIDANCE SHOWS BLAS REACHING HURRICANE INTENSITY...THERE IS
ABOUT A 30 PERCENT CHANCE THAT BLAS COULD BECOME A HURRICANE IN THE
NEXT 24 HOURS ACCORDING TO PROBABILISTIC GUIDANCE BASED ON
PREVIOUS NHC FORECAST ERRORS. SLOW WEAKENING IS FORECAST TO BEGIN
BY 24 HOURS AS BLAS MOVES OVER COOLER WATERS AND INTO A LESS
FAVORABLE THERMODYNAMIC ENVIRONMENT. THE OFFICIAL FORECAST IS CLOSE
TO THE LGEM GUIDANCE AND IS A LITTLE HIGHER THAN THE PREVIOUS
PACKAGE. BLAS SHOULD BECOME A REMNANT LOW IN 4 OR 5 DAYS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 19/1500Z 16.3N 109.7W 55 KT
12HR VT 20/0000Z 16.5N 111.0W 60 KT
24HR VT 20/1200Z 16.7N 112.8W 55 KT
36HR VT 21/0000Z 16.9N 114.8W 50 KT
48HR VT 21/1200Z 17.0N 116.8W 45 KT
72HR VT 22/1200Z 16.5N 120.5W 35 KT
96HR VT 23/1200Z 16.0N 124.5W 25 KT
120HR VT 24/1200Z 15.5N 128.0W 20 KT...POST-TROP/REMNT LOW

$$
FORECASTER BRENNAN

[cycloneye]

TPZ43 KNHC 192036
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
200 PM PDT SAT JUN 19 2010

A SERIES OF MICROWAVE IMAGES FROM AMSU...SSMIS...SSM/I...AND WINDSAT
SUGGEST THAT THE LOW-LEVEL CENTER OF BLAS REMAINS DISPLACED TO THE
NORTHEAST OF THE DEEP CONVECTION. THIS IS CONSISTENT WITH THE SHIPS
MODEL AND UW-CIMSS SATELLITE ANALYSIS THAT BOTH INDICATE ABOUT 10
KT OF NORTHEASTERLY TO EASTERLY SHEAR OVER BLAS. ALSO...THE
CYCLONE APPEARS TO BE INGESTING DRIER AND MORE STABLE AIR INTO THE
NORTHERN SIDE OF THE CIRCULATION...WHICH HAS LIKELY CONTRIBUTED TO
THE THINNING OF THE CLOUD SHIELD NORTH OF THE CENTER. WHILE THE
COVERAGE AND INTENSITY OF THE DEEP CONVECTION HAVE DECREASED A
LITTLE SINCE EARLIER TODAY...DVORAK FINAL T-NUMBERS REMAIN 3.5 FROM
BOTH TAFB AND SAB...AND THE INTENSITY IS HELD AT 55 KT FOR THIS
ADVISORY.

MOST OF THE GUIDANCE SUGGESTS THAT BLAS HAS PEAKED IN INTENSITY.
THE CYCLONE WILL BE MOVING INTO PROGRESSIVELY COOLER WATERS AND A
DRIER AND MORE STABLE ATMOSPHERIC ENVIRONMENT DURING THE PERIOD...
ESPECIALLY AFTER 48 HOURS. THE OFFICIAL FORECAST SHOWS A SLOW
WEAKENING BEGINNING AFTER 12 HOURS AND IS IN BEST AGREEMENT WITH
THE LGEM. BLAS SHOULD WEAKEN TO A REMNANT LOW BY THE END OF THE
PERIOD.

VISIBLE IMAGERY AND THE ABOVE-MENTIONED MICROWAVE PASSES LEND A
LITTLE MORE CONFIDENCE TO BOTH THE INITIAL POSITION ESTIMATE AND THE
INITIAL MOTION ESTIMATE OF 280/07. BLAS IS EXPECTED TO CONTINUE
MOVING WESTWARD SOUTH OF A DEEP-LAYER RIDGE THROUGH ABOUT 48 HOURS.
AFTER THAT TIME...AS THE CYCLONE WEAKENS...BLAS WILL BE STEERED A
LITTLE SOUTH OF DUE WEST BY THE LOW-LEVEL FLOW. THE NEW OFFICIAL
FORECAST IS A LITTLE NORTH OF THE PREVIOUS ONE DUE TO THE INITIAL
POSITION OF THE CYCLONE BEING FARTHER NORTH...AND REPRESENTS A
BLEND OF THE PREVIOUS FORECAST AND THE MULTI-MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 19/2100Z 16.7N 110.5W 55 KT
12HR VT 20/0600Z 16.9N 111.8W 55 KT
24HR VT 20/1800Z 17.1N 113.8W 50 KT
36HR VT 21/0600Z 17.3N 115.7W 45 KT
48HR VT 21/1800Z 17.3N 117.7W 40 KT
72HR VT 22/1800Z 17.0N 121.5W 35 KT
96HR VT 23/1800Z 16.5N 125.5W 25 KT...POST-TROP/REMNT LOW
120HR VT 24/1800Z 16.0N 129.0W 20 KT...POST-TROP/REMNT LOW

$$
FORECASTER BRENNAN

[cycloneye]

WTPZ43 KNHC 200240
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
800 PM PDT SAT JUN 19 2010

ALTHOUGH THE INTENSITY OF THE DEEP CONVECTION ASSOCIATED WITH BLAS
HAS CHANGED LITTLE OVER THE LAST SEVERAL HOURS...THE CONVECTIVE
PATTERN HAS BECOME LESS CIRCULAR. DVORAK T-NUMBERS ARE 2.5/35 KT
FROM SAB AND 3.0/45 KT FROM TAFB. THE CI-NUMBER FROM BOTH TAFB AND
SAB REMAIN AT 3.5/55 KT. THE INITIAL INTENSITY IS LOWERED TO 50
KT...CONSISTENT WITH THE AVERAGE OF THE SATELLITE ESTIMATES.
MICROWAVE IMAGES FROM TRMM...AMSR-E...AND AMSU CONFIRM THAT THE
LOW-LEVEL CENTER REMAINS NEAR THE NORTHEASTERN EDGE OF THE DEEP
CONVECTION.

THE INTENSITY GUIDANCE IS IN UNANIMOUS AGREEMENT THAT BLAS SHOULD
CONTINUE WEAKENING. WHILE THE SHIPS MODEL SHOWS NORTHEASTERLY
VERTICAL WIND SHEAR DECREASING DURING THE NEXT COUPLE OF DAYS...SEA
SURFACE TEMPERATURES STEADILY COOL ALONG THE FORECAST TRACK AND
BLAS IS EXPECTED TO MOVE INTO A MORE STABLE ATMOSPHERIC
ENVIRONMENT. THE OFFICIAL FORECAST SHOWS GRADUAL WEAKENING THROUGH
THE FORECAST PERIOD AND IS IN BEST AGREEMENT WITH THE INTENSITY
MODEL CONSENSUS AND THE FLORIDA STATE SUPER ENSEMBLE. BLAS IS NOW
FORECAST TO BE A REMNANT LOW IN 4 DAYS.

THE INITIAL MOTION ESTIMATE IS 285/7. GLOBAL MODELS SHOW MID-LEVEL
RIDGING REMAINING TO THE NORTH OF THE CYCLONE OVER THE NEXT FEW
DAYS. THIS SYNOPTIC PATTERN SHOULD TAKE BLAS ON A GENERAL WESTWARD
COURSE WITH AN INCREASE IN FORWARD SPEED OVER THE NEXT 48 HOURS.
BEYOND THAT TIME...BLAS...OR ITS REMNANTS...IS EXPECTED TO TRACK
SOUTH OF DUE WEST INFLUENCED MAINLY BY THE LOW-LEVEL FLOW. THE
OFFICIAL FORECAST IS AN UPDATE OF THE PREVIOUS ONE AND REMAINS NEAR
THE MULTI-MODEL CONSENSUS...TVCN.

FORECAST POSITIONS AND MAX WINDS

INITIAL 20/0300Z 17.0N 111.3W 50 KT
12HR VT 20/1200Z 17.2N 112.7W 50 KT
24HR VT 21/0000Z 17.4N 114.6W 45 KT
36HR VT 21/1200Z 17.5N 116.5W 40 KT
48HR VT 22/0000Z 17.5N 118.5W 35 KT
72HR VT 23/0000Z 17.0N 122.5W 30 KT
96HR VT 24/0000Z 16.5N 126.5W 25 KT...POST-TROP/REMNT LOW
120HR VT 25/0000Z 16.0N 130.0W 20 KT...POST-TROP/REMNT LOW

$$
FORECASTER CANGIALOSI/BEVEN

[cycloneye]

TROPICAL STORM BLAS DISCUSSION NUMBER 12...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
200 AM PDT SUN JUN 20 2010

CORRECTED TO INDICATE 48 HOUR POSITION AS POST-TROP/REMNT LOW

INFRARED SATELLITE IMAGES INDICATE THAT LARGE MASS OF DEEP
CONVECTION ASSOCIATED WITH BLAS HAS DECREASED CONSIDERABLY IN
INTENSITY AND COVERAGE DURING THE PAST SEVERAL HOURS. THE OVERALL
CONVECTIVE PATTERN HAS ALSO BECOME LESS SYMMETRIC AND A 0355 UTC
TRMM PASS INDICATED THAT THE CENTER WAS SLIGHTLY MORE REMOVED FROM
THE CONVECTION THAN IT WAS EARLIER. BASED UPON ITS CURRENT
APPEARANCE...THE CURRENT INTENSITY ESTIMATE IS LOWERED TO 40 KT FOR
THIS ADVISORY IN AGREEMENT WITH THE LATEST DVORAK INTENSITY
ESTIMATE OF FROM TAFB AND WITH RECENT CIMSS AODT VALUES BETWEEN 2.5
AND 3.0. ALTHOUGH THE MODEL GUIDANCE INDICATES THAT THERE SHOULD BE
A REDUCTION IN THE VERTICAL WIND SHEAR OVER BLAS DURING THE NEXT
24-48 HOURS...THE CYCLONE IS ALREADY MOVING OVER PROGRESSIVELY
LOWER SEA SURFACE TEMPERATURES AND ENCOUNTERING A MORE STABLE
ATMOSPHERE. THE ABOVE NEGATIVE FACTORS SHOULD OVERWHELM ANY
POSITIVE EFFECT FROM THE LOWER VERTICAL WIND SHEAR AND RESULT IN A
CONTINUED STEADY WEAKENING OVER THE NEXT FEW DAYS. THE OFFICIAL
FORECAST IS ADJUSTED DOWNWARD FROM THE PREVIOUS ADVISORY BASED UPON
CURRENT TRENDS...AND BLAS IS FORECAST TO BECOME
REMNANT LOW WITHIN 2 DAYS.

THE ABOVE TRMM PASS INDICATES THAT BLAS MAY BE MOVING SLIGHTLY RIGHT
OF THE PREVIOUS TRACK...WITH THE INITIAL MOTION ESTIMATE NOW
290/08. MIDDLE- TO UPPER-LEVEL RIDGING EXTENDING FROM THE SOUTH
CENTRAL UNITED STATES WEST-SOUTHWESTWARD INTO THE TROPICAL EAST
PACIFIC IS EXPECTED TO STEER BLAS ON WEST-NORTHWESTWARD TO WESTWARD
COURSE FOR THE NEXT DAY OR TWO. THEREAFTER...AS THE CYCLONE
WEAKENS FURTHER AND BECOMES MORE SHALLOW...IT SHOULD BE GUIDED
WESTWARD OR WEST-SOUTHWESTWARD BY THE LOW-LEVEL FLOW UNTIL
DISSIPATION. THE OFFICIAL FORECAST TRACK IS ADJUSTED SLIGHTLY
NORTHWARD TO ACCOUNT FOR THE MORE NORTHWARD INITIAL MOTION.



FORECAST POSITIONS AND MAX WINDS

INITIAL 20/0900Z 17.5N 112.3W 40 KT
12HR VT 20/1800Z 17.7N 113.7W 35 KT
24HR VT 21/0600Z 18.0N 115.7W 30 KT
36HR VT 21/1800Z 18.1N 117.6W 25 KT
48HR VT 22/0600Z 18.0N 119.6W 20 KT...POST-TROP/REMNT LOW
72HR VT 23/0600Z 17.2N 123.5W 20 KT...POST-TROP/REMNT LOW
96HR VT 24/0600Z...DISSIPATED

$$
FORECASTER KIMBERLAIN

[Chacor]

Down to 40.

EP, 03, 2010062012, , BEST, 0, 175N, 1129W, 40, 1001, TS, 34, NEQ, 50, 50, 40, 50, 1008, 150, 15, 0, 0, E, 0, , 0, 0, BLAS, M,

[HURAKAN]

Time is running out

[HURAKAN]

EP, 03, 2010062018, , BEST, 0, 178N, 1143W, 30, 1006, TD

To be downgraded to TD

[HURAKAN]

TROPICAL DEPRESSION BLAS ADVISORY NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
200 PM PDT SUN JUN 20 2010

...BLAS WEAKENS TO A DEPRESSION...


SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.9N 114.8W
ABOUT 470 MI...755 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/HR
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 13 MPH...20 KM/HR
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 200 PM PDT...2100 UTC...THE CENTER OF TROPICAL DEPRESSION BLAS
WAS LOCATED NEAR LATITUDE 17.9 NORTH...LONGITUDE 114.8 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST NEAR 13 MPH...20
KM/HR...AND A GENERAL WESTWARD MOTION IS EXPECTED FOR THE NEXT
COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS HAVE DECREASED TO NEAR 35 MPH...55
KM/HR...WITH HIGHER GUSTS. ADDITIONAL WEAKENING IS FORECAST...AND
BLAS IS EXPECTED TO BECOME A REMNANT LOW IN A DAY OR TWO.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...800 PM PDT.

$$
FORECASTER PASCH

[brunota2003]

Bye Bye Blas, you were an interesting little storm...stayed the same when you were supposed to strengthen, strengthen when you were supposed to weaken, and now you are poofing.

[HURAKAN]

TROPICAL DEPRESSION BLAS DISCUSSION NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010
200 PM PDT SUN JUN 20 2010

VERY LITTLE DEEP CONVECTION REMAINS IN ASSOCIATION WITH BLAS.
SATELLITE IMAGES SHOW ONLY A FEW CELLS OVER THE SOUTHERN SEMICIRCLE
OF THE CIRCULATION. LATEST DVORAK DATA T-NUMBERS ARE 1.5 FROM TAFB
AND SAB SO THE SYSTEM IS BEING DOWNGRADED TO A TROPICAL DEPRESSION
ON THIS ADVISORY. ALTHOUGH SOME DEEP CONVECTION COULD REDEVELOP
WITH THE DIURNAL MAXIMUM TONIGHT...OVERALL THE CIRCULATION SHOULD
CONTINUE TO SPIN DOWN AS IT MOVES OVER COOLER WATERS AND INTO A
MORE STABLE AIR MASS. THE OFFICIAL FORECAST SHOWS BLAS BECOMING A
REMNANT LOW IN 36 HOURS...ALTHOUGH THIS EVENT COULD CERTAINLY OCCUR
SOONER THAN THAT.

THE FORWARD MOTION IS NEAR 285/11. NO IMPORTANT CHANGES ARE MADE TO
THE TRACK FORECAST OR SYNOPTIC REASONING. A MID-LEVEL RIDGE AND
LOW-LEVEL FLOW SHOULD STEER THE TROPICAL CYCLONE OR REMNANT LOW ON
A MAINLY WESTWARD OR A LITTLE SOUTH OF WESTWARD COURSE UNTIL THE
CYCLONE LOSES ITS IDENTITY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 20/2100Z 17.9N 114.8W 30 KT
12HR VT 21/0600Z 18.1N 116.4W 25 KT
24HR VT 21/1800Z 18.2N 118.4W 25 KT
36HR VT 22/0600Z 18.1N 120.4W 20 KT...POST-TROP/REMNT LOW
48HR VT 22/1800Z 17.9N 122.4W 20 KT...POST-TROP/REMNT LOW
72HR VT 23/1800Z 17.5N 127.0W 20 KT...POST-TROP/REMNT LOW
96HR VT 24/1800Z...DISSIPATED

$$
FORECASTER PASCH

[HURAKAN]

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