EPAC: NORA - Remnants

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Re: EPAC: NORA - Tropical Storm

#41 Postby wxman57 » Mon Oct 12, 2015 10:10 am

I think the current intensity may be closer to 40-45 kts. Dvorak around 3.0, but that may be high, as the center is displaced SW of any convection.
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Re: EPAC: NORA - Tropical Storm

#42 Postby cycloneye » Mon Oct 12, 2015 3:53 pm

TROPICAL STORM NORA DISCUSSION NUMBER 14
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
1100 AM HST MON OCT 12 2015

THE LOW LEVEL CENTER OF NORA BECAME COMPLETELY EXPOSED THIS MORNING
AFTER THE OVERNIGHT BURST OF DEEP CONVECTION FADED AWAY. THE
SUBJECTIVE INTENSITY ESTIMATES ALL CAME IN AT 3.0 WITH AN
OBJECTIVE ESTIMATE OF 3.2 FROM CIMSS. BASED ON THESE VALUES...HAVE
LOWERED THE ADVISORY INTENSITY TO 50 KT...AND THIS IS PROBABLY
GENEROUS. THERE IS STILL A LOOSELY CURVED...BROKEN BAND OF DEEP
CONVECTION TO THE NORTHWEST THROUGH NORTHEAST OF THE CENTER.

NORA IS MOVING TOWARD THE WEST OR 280 DEGREES AT ABOUT 8 KT. IT IS
NEARING THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE. ONCE
IT DOES SO...A MORE WEST-NORTHWESTWARD MOTION IS EXPECTED TO BEGIN
IN THE NEAR TERM. THIS WILL BE FOLLOWED BY MORE OF A NORTHWARD
MOTION AS A MID-LEVEL TROUGH PASSES NORTH OF HAWAII AND A
BREAK DEVELOPS IN THE SUBTROPICAL RIDGE TO THE NORTHEAST OF THE
MAIN HAWAIIAN ISLANDS. THIS IS VERY LIKELY TO BE FOLLOWED BY AN
ABRUPT CHANGE IN DIRECTION TOWARD THE WEST-SOUTHWEST OR SOUTHWEST
AS STRONG DEEP LAYER SHEAR RENDERS NORA A REMNANT LOW. AS USUAL...
THERE IS SOME UNCERTAINTY AS TO WHEN THE STEERING FLOW BECOMES MORE
SHALLOW...BUT THE DEFINITIVE TREND OF THE GUIDANCE OVER THE LAST
SEVERAL CYCLES IS FOR THIS TO OCCUR SOONER AND THE LATEST FORECAST
REFLECTS THAT AS WELL.

DESPITE BEING OVER WARM SEA SURFACE TEMPERATURES...PERSISTENT
SOUTHWESTERLY SHEAR OF 25-30 KT CONTINUES TO LIMIT CONVECTION NEAR
THE CENTER OF NORA. AS ALLUDED TO ABOVE...THE SHEAR IS EXPECTED TO
PERSIST THROUGH THE REMAINDER OF NORA/S LIFE AS A TROPICAL
CYCLONE...SO CONTINUED GRADUAL WEAKENING IS EXPECTED. THE CURRENT
FORECAST HAS NORA BECOMING A REMNANT LOW IN 96 HOURS...BUT THIS
COULD OCCUR SOONER IF PERSISTENT DEEP CONVECTION CANNOT REESTABLISH
ITSELF.


FORECAST POSITIONS AND MAX WINDS

INIT 12/2100Z 12.8N 146.6W 50 KT 60 MPH
12H 13/0600Z 13.3N 147.9W 45 KT 50 MPH
24H 13/1800Z 14.0N 149.3W 40 KT 45 MPH
36H 14/0600Z 14.7N 150.0W 35 KT 40 MPH
48H 14/1800Z 15.5N 150.6W 30 KT 35 MPH
72H 15/1800Z 16.5N 151.0W 25 KT 30 MPH
96H 16/1800Z 16.2N 152.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 17/1800Z 15.5N 154.0W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
FORECASTER R BALLARD
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Re: EPAC: NORA - Tropical Storm

#43 Postby wxman57 » Mon Oct 12, 2015 3:56 pm

I agree, 50kts is quite generous...
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Re: EPAC: NORA - Tropical Storm

#44 Postby cycloneye » Tue Oct 13, 2015 12:41 pm

TROPICAL STORM NORA DISCUSSION NUMBER 17
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
500 AM HST TUE OCT 13 2015

DEEP CONVECTION HAS DEVELOPED OVER THE LOW LEVEL CIRCULATION CENTER
/LLCC/ OF NORA THIS MORNING...DESPITE THE STRONG WEST-SOUTHWESTERLY
WIND SHEAR. THE LATEST UW-CIMSS AND SHIPS WIND SHEAR ANALYSIS BOTH
SHOW AROUND 30 KNOTS OF SHEAR FROM THE WEST-SOUTHWEST. THE LATEST
FIXES FROM PHFO AND JTWC CAME IN AT 2.5/35 KNOTS...SAB 2.0/30
KNOTS...WHILE THE UW-CIMSS ADVANCED DVORAK TECHNIQUE /ADT/ CAME IN
AT 2.3/33 KNOTS. FOR THE CURRENT ADVISORY...THE INTENSITY WILL BE
HELD AT 40 KNOTS BASED ON A RE-SURGENCE OF DEEP CONVECTION OVER THE
LLCC. THE INITIAL MOTION WILL BE SET AT 315 DEGREES AT 6 KNOTS.

NORA IS CURRENTLY BEING STEERED TOWARD THE NORTHWEST BY AN UPPER
LEVEL RIDGE WELL NORTHEAST OF THE SYSTEM AND AN APPROACHING UPPER
LEVEL TROUGH CURRENTLY OVER THE HAWAIIAN ISLANDS. THE NORTHWESTWARD
MOTION IS EXPECTED TO CONTINUE OVER THE NEXT COUPLE OF DAYS WITH A
GRADUAL DECREASE IN FORWARD SPEED AS NORA BECOMES INCREASINGLY
INFLUENCED BY THE UPPER LEVEL TROUGH PASSING BY TO THE NORTH. ONCE
THE UPPER LEVEL TROUGH PASSES FAR ENOUGH EAST TO RELEASE ITS
INFLUENCE ON NORA...THE SYSTEM IS EXPECTED TO BE STEERED BY THE
PREVAILING TRADE WIND FLOW AND GENERALLY OFF TO THE WEST BETWEEN THE
48 HOUR FORECAST POINT AND DISSIPATION AT 120 HOURS. THE LATEST
OFFICIAL FORECAST TRACK FROM CPHC HAS BEEN SHIFTED TO THE RIGHT OF
THE PREVIOUS FORECAST TRACK. THIS IS LARGELY BASED ON A MORE
NORTHWARD INITIAL MOTION OF NORA...AS THE INFLUENCE OF THE
APPROACHING UPPER LEVEL TROUGH IS ALREADY BEING FELT. MODEL GUIDANCE
APPEARS TO BE SLOW IN REACTING TO THE INFLUENCE OF THE UPPER TROUGH
ON THE TRACK OF NORA...AND AS A RESULT THE FORECAST TRACK IS ON THE
EASTERN SIDE OF THE GUIDANCE ENVELOPE THROUGH 48 HOURS. BEYOND 48
HOURS ONCE THE INFLUENCE OF THE UPPER LEVEL TROUGH IS NO LONGER
BEING FELT...THE TRACK CLOSELY FOLLOWS THE PREVIOUS OFFICIAL
FORECAST TRACK.

NORA IS EXPECTED TO ONLY SLOWLY WEAKEN DURING THE NEXT SEVERAL DAYS
AS THE COMBINATION OF WARM SEA SURFACE TEMPERATURES /SSTS/ OF 28 TO
29C AND INCREASING UPPER SUPPORT FROM AN APPROACHING UPPER LEVEL
TROUGH...MAY BE ENOUGH TO ALLOW PULSING DEEP CONVECTION TO REMAIN
NEAR THE LLCC THROUGH WEDNESDAY. THIS IS DESPITE THE SIGNIFICANT
SHEAR FORECAST TO REMAIN IN PLACE THROUGH THE FORECAST CYCLE...AND
THE ABUNDANCE OF MID-LEVEL DRY AIR EVIDENT IN WATER VAPOR IMAGERY
NOW GETTING WRAPPED UP INTO THE SYSTEM. AS A RESULT...THE INTENSITY
FORECAST WILL KEEP NORA A MINIMAL TROPICAL STORM THROUGH
TONIGHT...WITH THE SYSTEM BECOMING A TROPICAL DEPRESSION ON
WEDNESDAY. ONCE THE INFLUENCE OF THE UPPER LEVEL TROUGH IS LOST
WEDNESDAY NIGHT...TROPICAL CHARACTERISTICS WILL STEADILY
DIMINISH...WITH THE SYSTEM EXPECTED TO BE A POST TROPICAL REMNANT
LOW BY FRIDAY EVENING AND DISSIPATED BY SATURDAY EVENING. THE
INTENSITY FORECAST FOR THIS ADVISORY REMAINS VERY CLOSE TO THE
INTENSITY FORECAST FROM THE PREVIOUS ADVISORY.






FORECAST POSITIONS AND MAX WINDS

INIT 13/1500Z 14.2N 148.6W 40 KT 45 MPH
12H 14/0000Z 14.8N 149.2W 35 KT 40 MPH
24H 14/1200Z 15.6N 149.9W 35 KT 40 MPH
36H 15/0000Z 16.2N 150.3W 30 KT 35 MPH
48H 15/1200Z 16.5N 150.7W 30 KT 35 MPH
72H 16/1200Z 16.5N 152.0W 25 KT 30 MPH
96H 17/1200Z 16.5N 154.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 18/1200Z...DISSIPATED
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Re: EPAC: NORA - Tropical Storm

#45 Postby cycloneye » Tue Oct 13, 2015 6:54 pm

TROPICAL STORM NORA DISCUSSION NUMBER 18
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
1100 AM HST TUE OCT 13 2015

NORA REMAINED RATHER POORLY ORGANIZED OVERNIGHT...BUT CUMULONIMBUS
CLOUDS...CB KEPT DEVELOPING NEAR THE CENTER. COLD...HIGH CLOUDS
SPREADING OUT FROM THE CB TOPS KEPT THE LOW LEVEL CIRCULATION CENTER
HIDDEN ON NIGHTTIME INFRARED IMAGERY. VISIBLE IMAGERY FROM 1730 AND
1800 UTC SHOWED THE LLCC VISIBLE THROUGH THIN CIRRUS HIGH CLOUDS
PROVIDING HIGH CONFIDENCE IN THE CENTER POSITION. SINCE THE 200 AM
CENTER POSITION WAS UNCERTAIN...I HAVE ADJUSTED THE 200 AM POSITION
TO SMOOTH OUT THE STORM MOTION. THE INITIAL MOTION WILL BE SET AT
300 DEGREES AT 8 KNOTS.

SUBJECTIVE DVORAK ANALYSES WERE 2.0/30 KNOTS FROM PHFO AND SAB AND
2.5/35 KT FROM JTWC ...WHILE THE UW-CIMSS ADT WAS 2.4/34 KNOTS. A
616 AM WINDSAT PASS SHOWED THE CIRCULATION ELONGATED ALONG A
NORTHEAST TO SOUTHWEST AXIS WITH STRONGER WINDS ON THE NORTH SIDE
OF THE CENTER AND ONLY LIGHT WINDS TO THE SOUTH. I HAVE KEPT THE
INITIAL INTENSITY AT 40 KT WITH TROPICAL-STORM FORCE WINDS
RESTRICTED TO THE NORTH SIDE OF THE SYSTEM.

A DEEP TROUGH ALOFT DIGGING SOUTH BETWEEN 150W AND 160W IS HELPING
PRODUCE RATHER STRONG VERTICAL WIND SHEAR...VWS...OVER NORA WITH
SHIPS SHOWING 29 KT FROM THE WEST SOUTHWEST AND UW-CIMSS SHOWING 31
KT FROM THE SOUTHWEST. SEA SURFACE TEMPERATURE...SST...WILL REMAIN A
RATHER WARM 28 DEGREES CELSIUS AS NORA MOVES NORTHWEST...BUT THE VWS
IS EXPECTED TO REMAIN STRONG ENOUGH FOR NORA TO KEEP WEAKENING. NORA
IS EXPECTED TO WEAKEN TO A DEPRESSION ON WEDNESDAY AND TO A
POST-TROPICAL/REMANNT LOW BY SATURDAY.

NORA IS MOVING NORTHWEST TOWARD A BREAK IN THE SUBTROPICAL RIDGE
PRODUCED BY THE DEEP TROUGH ALOFT TO THE NORTH. THE TRACK HAS BEEN
SHIFTED TO THE WEST IN THE SHORT TERM AS A RESULT OF RE-BESTING THE
200 AM POSITION. NORA IS STILL EXPECTED TO CURVE NORTHWEST TOWARD
THE WEAKNESS IN THE RIDGE WITH A SLIGHT DECREASE IN FORWARD MOTION
OVER THE NEXT TWO DAYS. BEYOND THAT...NORA IS FORECAST TO TURN
TOWARD THE WEST SOUTHWEST AS IT BECOMES A MORE SHALLOW SYSTEM
MOVING ALONG IN THE LOW-LEVEL EAST NORTHEAST FLOW.

FORECAST POSITIONS AND MAX WINDS

INIT 13/2100Z 14.5N 149.4W 40 KT 45 MPH
12H 14/0600Z 14.9N 150.0W 35 KT 40 MPH
24H 14/1800Z 15.6N 150.6W 30 KT 35 MPH
36H 15/0600Z 16.0N 151.0W 25 KT 30 MPH
48H 15/1800Z 16.5N 151.5W 25 KT 30 MPH
72H 16/1800Z 16.9N 152.8W 25 KT 30 MPH
96H 17/1800Z 16.5N 155.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 18/1800Z 16.5N 158.5W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
FORECASTER DONALDSON
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Re: EPAC: NORA - Tropical Storm

#46 Postby cycloneye » Tue Oct 13, 2015 9:46 pm

TROPICAL STORM NORA DISCUSSION NUMBER 19
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
500 PM HST TUE OCT 13 2015

SINCE THIS MORNING...THE LOW LEVEL CIRCULATION CENTER OF NORA HAS
REMAINED EXPOSED AND THE COLD...HIGH CLOUD TOPS OVER NORA HAVE
SHIFTED FARTHER OFF TO THE EAST OF THE CENTER. SPIRALING LOW CLOUDS
MAKE IT EASY TO LOCATE THE CENTER AND DETERMINE THE CURRENT MOTION
WITH A HIGH DEGREE OF CONFIDENCE. THE INITIAL MOTION IS 305 DEGREES
AT 7 KNOTS.

SUBJECTIVE DVORAK ANALYSES WERE 2.0/30 KNOTS FROM PHFO..SAB AND
JTWC...WHILE THE UW-CIMSS ADT WAS 2.6/37 KNOTS. A 903 AM ASCAT PASS
SHOWED 35 KT WINDS WITHIN 50 NM OF THE CENTER IN THE NORTH QUADRANT
OF THE STORM. I HAVE LOWERED THE INITIAL INTENSITY TO 35 KNOTS...
WITH TROPICAL-STORM FORCE WINDS RESTRICTED TO THE NORTH SIDE OF THE
SYSTEM.

A DEEP TROUGH ALOFT DIGGING SOUTH BETWEEN 150W AND 160W CONTINUES
PRODUCING STRONG VERTICAL WIND SHEAR...VWS...OVER NORA. SHIPS SHOWS
30 KT FROM THE WEST SOUTHWEST AND UW-CIMSS SHOWS 30 KT FROM THE
SOUTHWEST. THE SEA SURFACE TEMPERATURE...SST...WILL REMAIN A RATHER
WARM 28 DEGREES CELSIUS AS NORA MOVES NORTHWEST...BUT THE VWS IS
EXPECTED TO REMAIN STRONG ENOUGH FOR NORA TO KEEP WEAKENING. NORA IS
EXPECTED TO WEAKEN TO A DEPRESSION TONIGHT AND TO A
POST-TROPICAL/REMNANT LOW BY WEDNESDAY NIGHT.

NORA IS MOVING NORTHWEST TOWARD A BREAK IN THE SUBTROPICAL RIDGE
PRODUCED BY THE DEEP TROUGH ALOFT TO THE NORTH. NORA IS EXPECTED TO
CURVE NORTHWEST TOWARD THE WEAKNESS IN THE RIDGE WITH A DECREASE IN
FORWARD MOTION THROUGH FRIDAY. BEYOND THAT...THE REMNANT OF NORA IS
FORECAST TO TURN TOWARD THE WEST SOUTHWEST AS IT BECOMES A MORE
SHALLOW SYSTEM MOVING ALONG IN THE LOW-LEVEL EAST NORTHEAST FLOW.


FORECAST POSITIONS AND MAX WINDS

INIT 14/0300Z 15.0N 150.0W 35 KT 40 MPH
12H 14/1200Z 15.5N 150.5W 30 KT 35 MPH
24H 15/0000Z 16.0N 151.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 15/1200Z 16.5N 151.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 16/0000Z 16.9N 152.1W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 17/0000Z 17.0N 154.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 18/0000Z 16.0N 157.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 19/0000Z...DISSIPATED

$$
FORECASTER DONALDSON
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Re: EPAC: NORA - Tropical Depression

#47 Postby cycloneye » Wed Oct 14, 2015 5:11 am

TROPICAL DEPRESSION NORA DISCUSSION NUMBER 20
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
1100 PM HST TUE OCT 13 2015

THE SATELLITE PRESENTATION OF NORA CONTINUES TO LOOK VERY RAGGED
THIS EVENING...WITH THE LOW LEVEL CIRCULATION CENTER /LLCC/
COMPLETELY EXPOSED. OVER THE PAST COUPLE OF HOURS...CONVECTION HAS
MANAGED TO RE-DEVELOP NORTHEAST OF LLCC...BUT IT IS BATTLING STRONG
SOUTHWESTERLY VERTICAL WIND SHEAR. THE LATEST UW-CIMSS VERTICAL
WIND SHEAR ANALYSIS SHOWS 40 KNOTS OF SHEAR FROM THE SOUTHWEST AND
SHIPS GUIDANCE SHOWS 32 KNOTS OF SHEAR FROM THE SOUTHWEST. THE
LATEST FIXES FROM PHFO AND JTWC CAME IN AT 1.5/25 KNOTS...SAB
2.0/30 KNOTS...WHILE THE UW-CIMSS ADVANCED DVORAK TECHNIQUE /ADT/
CAME IN AT 2.0/30 KNOTS. ADDITIONALLY...A 0708Z ASCAT PASS SHOWED A
LARGE SWATH OF 25 KNOT WINDS IN THE NORTHERN SEMI-CIRCLE OF NORA.
BASED ON THE FIXES AND RECENT ASCAT PASS...THE INTENSITY FOR THIS
ADVISORY HAS BEEN LOWERED TO 30 KNOTS...MAKING NORA A TROPICAL
DEPRESSION. THE INITIAL MOTION WILL BE SET AT 280 DEGREES AT 5
KNOTS.

DUE TO THE LOSS OF DEEP CONVECTION...NORA IS CURRENTLY BEING
STEERED OFF TO THE WEST BY THE LOW LEVEL TRADE WIND FLOW. THIS
MOTION IS EXPECTED TO BE TEMPORARY AS THE APPROACH OF A LARGE UPPER
LEVEL TROUGH AND FORCING FROM THE RIGHT REAR QUAD OF AN UPPER LEVEL
JET WILL LIKELY ALLOW CONVECTION TO PULSE OVER THE SYSTEM THROUGH
THURSDAY MORNING...AND STEER NORA ON A MORE NORTHWESTWARD TRACK.
ONCE THE INFLUENCE OF THE UPPER DYNAMICS IS LOST...NORA IS EXPECTED
TO GET CAUGHT UP WITHIN THE TRADE WIND FLOW ONCE AGAIN...TRACKING
GENERALLY WESTWARD THROUGH DISSIPATION FRIDAY NIGHT OR SATURDAY.
THE OFFICIAL CPHC FORECAST TRACK IS TO THE LEFT OF THE GUIDANCE
ENVELOPE AND THE PREVIOUS OFFICIAL FORECAST THROUGH 36 HOURS DUE TO
THE INITIAL WESTWARD MOTION. THE TRACK THEN CLOSELY FOLLOWS THE
PREVIOUS OFFICIAL FORECAST FROM HOURS 36 THROUGH 72.

NORA IS EXPECTED TO SLOWLY AND STEADILY WEAKEN OVER THE NEXT
SEVERAL DAYS AS PERSISTENT VERTICAL WIND SHEAR OF 30 TO 35 KNOTS AS
INDICATED BY SHIPS GUIDANCE...WILL LIKELY KEEP THE LLCC DEVOID OF
DEEP CONVECTION. THIS IN COMBINATION WITH THE MID-LEVEL DRY AIR
EVIDENT IN WATER VAPOR IMAGERY WILL NEGATE ANY POSITIVE
CONTRIBUTION FROM WARM SEA SURFACE TEMPERATURES /SSTS/ OF AROUND 28
DEGREES C. AS A RESULT...NORA IS EXPECTED TO BECOME A POST-TROPICAL
REMNANT LOW ON WEDNESDAY...WITH THE SYSTEM DISSIPATING FRIDAY NIGHT
OR SATURDAY IF NOT SOONER.






FORECAST POSITIONS AND MAX WINDS

INIT 14/0900Z 14.8N 150.6W 30 KT 35 MPH
12H 14/1800Z 15.2N 151.3W 30 KT 35 MPH
24H 15/0600Z 16.0N 152.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 15/1800Z 16.4N 152.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 16/0600Z 16.6N 153.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 17/0600Z 16.5N 155.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 18/0600Z...DISSIPATED

$$
FORECASTER JELSEMA/WROE
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Re: EPAC: NORA - Tropical Depression

#48 Postby cycloneye » Wed Oct 14, 2015 9:47 pm

TROPICAL DEPRESSION NORA DISCUSSION NUMBER 23
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
500 PM HST WED OCT 14 2015

NORA CONTINUES TO WEAKEN...BUT VERY SLOWLY. THE LOW CLOUD LINES
AROUND THE CENTER OF NORA HAVE BECOME LESS TIGHTLY WRAPPED...MORE
SPIRAL SHAPED THAN CIRCULAR...OVER THE PAST 24 HOURS BUT
CUMULONIMBUS CLOUDS CONTINUE TO FORM NORTHEAST OF THE CENTER. THERE
HAVE BEEN NO RECENT SCATTEROMETER PASSES OVER THE SYSTEM.
SUBJECTIVE DVORAK INTENSITY ANALYSES WERE 1.5/25 KNOTS FROM HFO...
JTWC AND SAB...WHILE THE OBJECTIVE ANALYSIS FROM UW-CIMSS WAS
2.3/33 KNOTS. I HAVE KEPT THE INITIAL INTENSITY AT 25 KNOTS.

THE LOW LEVEL CIRCULATION CENTER HAS REMAINED EXPOSED MOST OF THE
DAY...ALLOWING HIGH CONFIDENCE IN THE FIX POSITIONS. THE FORWARD
MOTION HAS BEEN 325 DEGREES AT 5 KT FOR THE PAST SEVERAL HOURS. THE
FORECAST TRACK HAS BEEN SHIFTED TO THE RIGHT...FARTHER NORTH...THAN
THE PREVIOUS TRACK BASED ON THE RECENT MOTION.

NORA IS PART OF A TROUGH IN THE EASTERLY TRADE-WIND FLOW SOUTH OF
THE SUBTROPICAL RIDGE. OVER THE NEXT 36 HOURS OR SO THE TROUGH WILL
BULGE NORTH INTO A WEAKNESS IN THE RIDGE AND THE DEPRESSION WILL
CONTINUE MOVING SLOWLY NORTHWESTWARD IN THIS TROUGH. AFTER 36
HOURS THE SUBTROPICAL RIDGE WILL REBUILD AND NORA WILL MOVE OFF TO
THE WEST SOUTHWEST.

STRONG VERTICAL WIND SHEAR...VWS...CONTINUES OVER NORA WITH SHIPS
AND UW-CIMSS BOTH SHOWING ABOUT 36 KNOTS OF SHEAR FROM THE
SOUTHWEST. THE DEPRESSION HAS PROBABLY SURVIVED ONLY BECAUSE IT HAS
REMAINED OVER VERY WARM 28 DEGREE CELSIUS WATER. THE VWS IS
FORECAST TO REMAIN OVER 35 KNOTS OVERNIGHT. WE EXPECT THAT WILL BE
ENOUGH TO SHEAR AWAY THE REMAINING CONVECTION NEAR THE DEPRESSION
AND THAT NORA WILL WEAKEN TO A POST-TROPICAL/REMNANT LOW BY
TOMORROW.

THE WIND FIELD AROUND NORA IS FORECAST TO CONTINUE TO WEAKEN BUT
THE MOISTURE FIELD WILL LIKELY HELP BOOST RAINFALL OVER THE MAIN
HAWAIIAN ISLANDS THROUGH THE WEEKEND. SEE THE PUBLIC FORECASTS FROM
THE WEATHER FORECAST OFFICE IN HONOLULU FOR DETAILS.


FORECAST POSITIONS AND MAX WINDS

INIT 15/0300Z 15.5N 151.4W 25 KT 30 MPH
12H 15/1200Z 16.0N 151.7W 25 KT 30 MPH
24H 16/0000Z 16.6N 152.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 16/1200Z 16.8N 152.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 17/0000Z 16.7N 154.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 18/0000Z 16.0N 156.9W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 19/0000Z...DISSIPATED

$$
FORECASTER DONALDSON
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#49 Postby supercane » Thu Oct 15, 2015 9:42 am

WTPA44 PHFO 150832
TCDCP4

TROPICAL DEPRESSION NORA DISCUSSION NUMBER 24
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
1100 PM HST WED OCT 14 2015

THE SATELLITE PRESENTATION OF NORA HAS BEEN DEGRADING UNDER STRONG
SOUTHWESTERLY VERTICAL WIND SHEAR OF 30 TO 40 KT ACCORDING TO SHIPS
AND THE RECENT CIMSS ANALYSIS. BURSTS OF DEEP CONVECTION CLOSER TO
THE EXPOSED LOW LEVEL CENTER DISSIPATED EARLY THIS AFTERNOON...
GIVING WAY TO LOWER TOPPED THUNDERSTORMS WITHIN A BAND IN THE
EASTERN SEMICIRCLE. DVORAK FINAL T NUMBERS AND CURRENT INTENSITY
ESTIMATES FROM HFO...JTWC...AND SAB AGAIN CAME IN AT 1.0 AND
1.5...RESPECTIVELY...SUPPORTING AN INITIAL INTENSITY OF 25 KT.

NORA IS MOVING TOWARD THE NORTHWEST...OR 325 DEG...AT 6 KT TOWARD A
WEAKNESS IN THE SUBTROPICAL RIDGE CREATED BY A DEEP TROUGH CENTERED
JUST NORTH OF HAWAII. THIS MOTION WILL CONTINUE THROUGH THURSDAY
WHILE THE TROUGH CONTINUES TO IMPART STRONG VERTICAL WIND SHEAR
THAT SHOULD WEAKEN NORA TO A REMNANT LOW. THE SHALLOW REMNANT LOW
IS FORECAST TO TAKE A TURN TOWARD THE WEST ON THURSDAY NIGHT AND
FRIDAY AS LOW LEVEL RIDGING BUILDS TO THE NORTH OF HAWAII. ALL OF
THE GUIDANCE SHOWS WEAKENING...WITH SHIPS SUGGESTING DISSIPATION AS
EARLY AS THURSDAY AFTERNOON AND THE GFS AND ECMWF OPENING THE
SYSTEM INTO A TROUGH LATE FRIDAY. THE FORECAST WAS CHANGED LITTLE
FROM THE PRIOR PACKAGE...FOLLOWING THE LEFT SIDE OF A RATHER
TIGHTLY CLUSTERED DYNAMICAL AND CONSENSUS GUIDANCE ENVELOPE.



FORECAST POSITIONS AND MAX WINDS

INIT 15/0900Z 16.1N 151.9W 25 KT 30 MPH
12H 15/1800Z 16.6N 152.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 16/0600Z 17.0N 152.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
36H 16/1800Z 17.0N 153.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 17/0600Z 16.8N 155.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 18/0600Z...DISSIPATED

$$
FORECASTER WROE

----------------------------------------------------------------------------------------------

WTPA44 PHFO 151430
TCDCP4

TROPICAL DEPRESSION NORA DISCUSSION NUMBER 25
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
500 AM HST THU OCT 15 2015

DEEP CONVECTION HAS REDEVELOPED ONCE AGAIN NEAR THE LOW LEVEL CENTER
IN THE PAST SEVERAL HOURS. THE LOW LEVEL CENTER HAD BEEN EXPOSED FOR
MORE THAN A DAY DUE TO STRONG AND PERSISTENT SOUTHWESTERLY VERTICAL
WIND SHEAR OF AROUND 30 KT ACCORDING TO SHIPS AND THE RECENT CIMSS
ANALYSIS...AND THE STRONG WINDS ALOFT PRODUCING THE SHEAR HAVE
CAUSED DEEP CONVECTION TO PERIODICALLY PULSE THEN COLLAPSE. DVORAK
CURRENT INTENSITY ESTIMATES CAME IN AT 1.5 FROM HFO...SAB...JTWC...
AND CIMSS ADT...SUPPORTING AN INITIAL INTENSITY OF 25 KT.

NORA CONTINUES TO MOVE TOWARD THE NORTHWEST...OR 320 DEGREES...AT 6
KT INTO A WEAKNESS IN THE SUBTROPICAL RIDGE CREATED BY A DEEP MID
TO UPPER LEVEL TROUGH OVER HAWAII. NORA IS EXPECTED TO TURN TOWARD
THE WEST TONIGHT AS THE INCREASINGLY WEAK AND SHALLOW SYSTEM
BECOMES STEERED BY THE LOW LEVEL EASTERLY FLOW. AS THE UPPER LEVEL
TROUGH PARKED OVER THE REGION MAINTAINS VERTICAL WIND SHEAR OF
AROUND 30 KT DURING THE NEXT FEW DAYS...NORA IS EXPECTED TO BECOME A
REMNANT LOW LATER TODAY OR TONIGHT...AND THE FORECAST CALLS FOR
DISSIPATION LATE FRIDAY...WHICH IS SLIGHTLY LATER THAN SHIPS...GFS
AND ECMWF. THE FORECAST TRACK WAS CHANGED LITTLE FROM THE PRIOR
PACKAGE AND IS NEAR THE MIDDLE OF A RATHER TIGHTLY CLUSTERED
DYNAMICAL AND CONSENSUS GUIDANCE ENVELOPE.




FORECAST POSITIONS AND MAX WINDS

INIT 15/1500Z 16.6N 152.4W 25 KT 30 MPH
12H 16/0000Z 17.0N 152.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 16/1200Z 17.2N 153.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
36H 17/0000Z 17.1N 155.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 17/1200Z...DISSIPATED

$$
FORECASTER WROE
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supercane
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Re: EPAC: NORA - Tropical Depression

#50 Postby supercane » Thu Oct 15, 2015 3:58 pm

124
WTPA44 PHFO 152036
TCDCP4

REMNANTS OF NORA DISCUSSION NUMBER 26
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP182015
1100 AM HST THU OCT 15 2015

NORA HAS GIVEN IN TO PERSISTENT AND DEBILITATING SOUTHWESTERLY
SHEAR...AND VISIBLE SATELLITE IMAGERY INDICATES THAT THE LOW-LEVEL
CIRCULATION IS NO LONGER IDENTIFIABLE. SINCE THE CYCLONE CENTER HAS
DISSIPATED...AND SHEAR WILL REMAIN SUFFICIENTLY STRONG TO PRECLUDE
REDEVELOPMENT...THIS WILL BE THE FINAL ADVISORY ON THE REMNANTS OF
NORA.


FORECAST POSITIONS AND MAX WINDS

INIT 15/2100Z 16.7N 153.0W 25 KT 30 MPH...REMNANTS
12H 16/0600Z...DISSIPATED

FORECASTER BIRCHARD
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