Tropical Depression Emilia

[summer blizzard]

Another Tropical Depression has formed in the eastern Pacific...

000

WTPZ41 KNHC 211442

TCDEP1

TROPICAL DEPRESSION SIX-E DISCUSSION NUMBER 1

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062006

800 AM PDT FRI JUL 21 2006

THE AREA OF DISTURBED WEATHER THAT NHC HAS BEEN MONITORING FOR THE

PAST SEVERAL DAYS HAS DEVELOPED A SURFACE CIRCULATION AND ENOUGH

DEEP CONVECTION TO BE CLASSIFIED AS A TROPICAL DEPRESSION. VISIBLE

IMAGES INDICATE THAT THE DEPRESSION IS SHEARED AND THE CENTER IS

LOCATED TO THE EAST THE MAIN CONVECTION. THE SHEAR IS FORECAST TO

GRADUALLY RELAX AND THE OCEAN IS WARM. THEREFORE...A GRADUAL

STRENGTHENING IS INDICATED.

THE BEST ESTIMATE OF THE INITIAL MOTION IS 320 DEGREES AT 3 KNOTS.

THE STEERING CURRENTS ARE WEAK...SO A SLOW NORTHWESTWARD MOTION IS

INDICATED FOR A DAY OR TWO. THEREAFTER...A GRADUAL INCREASE IN

FORWARD SPEED IS INDICATED AS A MIDDLE-LEVEL RIDGE BUILDS TO THE

NORTHEAST OF THE CYCLONE. BOTH ECMWF AND THE GFDL HAVE A MORE

AGGRESSIVE NORTHWESTWARD TRACK WHILE THE GFS SHOWS A WEST-NORTHWEST

MOTION. THE OFFICIAL FORECAST IS IN BETWEEN THESE TWO OPTIONS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 21/1500Z 12.1N 103.1W 25 KT

12HR VT 22/0000Z 12.3N 103.5W 30 KT

24HR VT 22/1200Z 13.0N 104.5W 35 KT

36HR VT 23/0000Z 14.0N 106.0W 35 KT

48HR VT 23/1200Z 15.0N 107.5W 40 KT

72HR VT 24/1200Z 17.0N 109.5W 45 KT

96HR VT 25/1200Z 19.0N 112.0W 45 KT

120HR VT 26/1200Z 22.0N 115.0W 45 KT

As you can see, a gradual strengthening is forecast with sustained windspeeds reaching 50mph in 72 hours before no further strengthening, i believe that the GFS has the track right on this one and given that Hurricane Daniel exploded over the warm waters of the East Pacific, and the fact that shear will lessen, i am forecasting a category 1 hurricane in 72 hours peaking as a weak category 3 hurricane in around 120 hours.

[summer blizzard]

This system is now Tropical Storm Emilia, could a moderator change the thread title please...

000

WTPZ41 KNHC 220832

TCDEP1

TROPICAL STORM EMILIA DISCUSSION NUMBER 4

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062006

200 AM PDT SAT JUL 22 2006

INFRARED SATELLITE IMAGERY SHOWS THAT A LARGE BURST OF CONVECTION

HAS DEVELOPED NEAR OR JUST WEST OF THE LOW-LEVEL CENTER...WITH

CLOUD TOPS NEAR -85C. WHILE A SSM/I OVERPASS AT 0232Z SHOWS THAT

THE CYCLONE IS STILL SHEARED...SATELLITE INTENSITY ESTIMATES ARE

NOW 45 KT FROM TAFB AND SAB...AND 30 KT FROM AFWA. BASED ON

THIS...TROPICAL DEPRESSION SIX-E IS UPGRADED TO TROPICAL STORM

EMILIA WITH 35-KT WINDS.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 330/6. LARGE-SCALE MODEL

ANALYSES AND WATER VAPOR IMAGERY INDICATE THAT EMILIA IS ON THE

SOUTHEAST SIDE OF A MID/UPPER-LEVEL RIDGE CENTERED OVER

NORTHWESTERN MEXICO. DUE TO THIS...MOST OF THE TRACK GUIDANCE

CALLS FOR A GENERALLY NORTHWESTWARD OR WEST-NORTHWESTWARD MOTION

THROUGH THE FORECAST PERIOD. ONE EXCEPTION TO THIS IS THE

GFS...WHICH TURNS EMILIA MORE WESTWARD AND IS THE LEFT OUTLIER OF

THE TRACK FORECAST MODELS. THE NEW FORECAST TRACK FOLLOWS THE

CONSENSUS OF THE OTHER GUIDANCE...CALLING FOR A GENERALLY

NORTHWESTWARD MOTION FOR THE NEXT 5 DAYS AND IS AN UPDATE OF THE

PREVIOUS TRACK. HOWEVER...GIVEN THE STRENGTH OF THE RIDGE THE GFS

SOLUTION CANNOT BE RULED OUT.

ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN SHOW THAT EMILIA

IS UNDER 20-25 KT OF EASTERLY VERTICAL WIND SHEAR. THIS SHOULD AT

LEAST SLOW INTENSIFICATION IN THE SHORT-TERM. THE LARGE-SCALE

MODELS FORECAST THE SHEAR TO GRADUALLY DECREASE DURING THE NEXT 3

DAYS...WHICH IF CORRECT SHOULD ALLOW GRADUAL STRENGTHENING. THE

GFDL MODEL CALLS FOR EMILIA TO PEAK AT 50 KT IN 48 HR...WHILE THE

SHIPS MODEL CALLS FOR IT TO BECOME A HURRICANE IN ABOUT 72 HR. THE

INTENSITY FORECAST CALLS FOR SLOW INTENSIFICATION TO JUST UNDER

HURRICANE STRENGTH BY 72 HR...FOLLOWED BY WEAKENING OVER COOLER SEA

SURFACE TEMPERATURES BY 120 HR. THE NEW INTENSITY FORECAST IS A

LITTLE STRONGER THAN THE PREVIOUS PACKAGE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 22/0900Z 13.8N 104.0W 35 KT

12HR VT 22/1800Z 14.6N 104.9W 40 KT

24HR VT 23/0600Z 15.8N 106.4W 45 KT

36HR VT 23/1800Z 16.8N 108.0W 50 KT

48HR VT 24/0600Z 17.7N 109.4W 55 KT

72HR VT 25/0600Z 19.5N 112.0W 60 KT

96HR VT 26/0600Z 21.0N 114.5W 60 KT

120HR VT 27/0600Z 23.0N 117.0W 50 KT

$$

FORECASTER BEVEN

[wolves78]

000

WTPZ41 KNHC 231440

TCDEP1

TROPICAL STORM EMILIA DISCUSSION NUMBER 9

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062006

800 AM PDT SUN JUL 23 2006

CONVECTION HAS INCREASED MARKEDLY DURING THE PAST 6 HOURS...AND BOTH

CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY INDICATE EMILIA HAS

BECOME MUCH BETTER ORGANIZED. THE INTENSITY HAS BEEN INCREASED TO

55 KT BASED ON A DVORAK INTENSITY ESTIMATE OF T3.5 FROM TAFB...A

DATA T-NUMBER OF T3.5 FROM SAB...AND A UW-CIMSS 3-H AVERAGE ADT OF

T3.6/57 KT.

THERE REMAINS SOME UNCERTAINTY IN THE EXACT POSITION AND FORWARD

MOTION OF EMILIA...BUT MY BEST ESTIMATE IS 300/09 KT BASED ON

LIMITED MICROWAVE SATELLITE DATA. A LARGE AND RATHER STOUT MID- TO

UPPER-LEVEL SUBTROPICAL RIDGE CENTERED OVER THE SOUTHWESTERN U.S.

AND EXTENDING SOUTH AND SOUTHEASTWARD INTO MEXICO IS FORECAST TO

WEAKEN SLIGHTLY BUT BASICALLY REMAIN INTACT FOR THE NEXT SEVERAL

DAYS. AS SUCH...THE EAST TO SOUTHEASTERLY DEEP-LAYER STEERING FLOW

ON THE SOUTH SIDE OF THE RIDGE SHOULD KEEP EMILIA MOVING IN A

GENERAL WEST-NORTHWEST TO NORTHWESTWARD DIRECTION. THE MAJORITY OF

THE NHC MODEL GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO. THE

EXCEPTIONS ARE THE GFS AND THE GFS ENSEMBLE MODELS WHICH TAKE EMILIA

QUICKLY WESTWARD FROM ITS CURRENT POSITION...WHICH SEEMS RATHER

UNLIKELY AT THIS TIME. THE OFFICIAL FORECAST TRACK IS VERY CLOSE TO

THE PREVIOUS TRACK AND THE CONU CONSENSUS MODEL.

NOW THAT CENTRAL DEEP CONVECTION HAS DEVELOPED AND RECENT AMSU AND

AMSR MICROWAVE DATA INDICATE AN EYEWALL WAS FORMING...EMILIA IS

EXPECTED TO INTENSIFY AT A FASTER RATE THAN PAST TRENDS HAVE BEEN.

IN FACT...THE LOW SHEAR ENVIRONMENT...IMPROVING OUTFLOW PATTERN IN

ALL QUADRANTS...AND NEAR-30C SSTS SUGGEST THAT EMILIA MAY BEGIN A

PERIOD OF RAPID INTENSIFICATION WITHIN THE NEXT 6-12 HOURS. THE

RESULT WOULD BE A STRONGER CYCLONE THROUGH 48 HOURS...AFTER WHICH

WEAKENING IS EXPECTED DUE TO EMILIA MOVING OVER MUCH COOLER WATER.

FORECAST POSITIONS AND MAX WINDS

INITIAL 23/1500Z 18.1N 107.4W 55 KT

12HR VT 24/0000Z 18.8N 108.5W 65 KT

24HR VT 24/1200Z 19.5N 110.1W 75 KT

36HR VT 25/0000Z 20.2N 111.5W 80 KT

48HR VT 25/1200Z 20.9N 113.0W 80 KT

72HR VT 26/1200Z 22.3N 115.7W 55 KT

96HR VT 27/1200Z 24.0N 118.5W 35 KT...DISSIPATING

120HR VT 28/1200Z 26.0N 121.5W 25 KT...REMNANT LOW

[Somerset Squall]

000

WTPZ41 KNHC 232026

TCDEP1

TROPICAL STORM EMILIA DISCUSSION NUMBER 10

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062006

200 PM PDT SUN JUL 23 2006

CONVECTIVE BANDING HAS CONTINUED TO INCREASE AND IMPROVE. T-NUMBERS

FROM ALL THREE AGENCIES ARE A CONSENSUS T3.5/55 KT...AND A 3-HR

AVERAGE ADT FROM UW-CIMSS IS T3.7/59 KT. GIVEN THE BANDING EYE

FEATURE OCCASIONALLY APPEARING IN BOTH CONVENTIONAL AND MICROWAVE

SATELLITE IMAGERY...THE INTENSITY IS INCREASED TO 60 KT.

THE INITIAL MOTION IS 300/07 KT. THE FORWARD SPEED HAS DECREASED

SLIGHTLY...WHICH IS LIKELY JUST A TEMPORARY TREND AND PROBABLY DUE

TO THE INNER CORE BECOMING BETTER ORGANIZED. THE LARGE MID- TO

UPPER-LEVEL SUBTROPICAL RIDGE CENTERED OVER THE SOUTHWESTERN U.S.

AND EXTENDING SOUTHEASTWARD INTO MEXICO IS FORECAST TO REMAIN IN

PLACE FOR THE NEXT SEVERAL DAYS. DEEP-LAYER SOUTHEAST TO EASTERLY

STEERING FLOW ALONG THE SOUTHERN PERIPHERY OF THE RIDGE SHOULD

FORCE EMILIA ON A GENERAL WEST-NORTHWEST TO NORTHWESTWARD TRACK

THROUGHOUT THE FORECAST PERIOD. THE NHC MODEL GUIDANCE IS IN MUCH

BETTER AGREEMENT NOW WITH THE GFS AND THE GFS ENSEMBLE MODELS

HAVING MADE A SIGNIFICANT NORTHWARD SHIFT INTO THE MAIN MODEL

GUIDANCE ENVELOPE. THE OFFICIAL FORECAST TRACK IS JUST AN EXTENSION

OF THE PREVIOUS TRACK AND IS SIMILAR TO THE CONU CONSENSUS MODEL.

CONVECTIVE BANDS CONTINUE TO DEVELOP AND WRAP TIGHTLY AROUND THE

CIRCULATION CENTER...AND AN EYE MAY BECOME APPARENT IN CONVENTIONAL

IMAGERY DURING THE NEXT 6-12 HOURS IF THE RECENT DEVELOPMENT TREND

CONTINUES. THE UPPER-LEVEL OUTFLOW HAS CONTINUED TO EXPAND AND

BECOME MORE SYMMETRICAL. FOR THE NEXT 24 HOURS OR SO...EMILIA IS

EXPECTED TO REMAIN OVER SSTS OF 28-29C AND IN A LOW OR NO SHEAR

ENVIRONMENT. ALL OF THESE FACTORS SUGGEST THAT A PERIOD OF RAPID

INTENSIFICATION ENSUE SHORTLY...AND THIS IS REFLECTED IN THE

OFFICIAL INTENSITY FORECAST BETWEEN THE 12H TO 24 H FORECAST

PERIODS. BY 48 HOURS...EMILIA IS FORECAST TO BE MOVING OVER SUB-25C

SSTS...WHICH SHOULD INDUCE A STEADY OR RAPID WEAKENING TREND.

FORECAST POSITIONS AND MAX WINDS

INITIAL 23/2100Z 18.4N 107.8W 60 KT

12HR VT 24/0600Z 19.0N 109.0W 70 KT

24HR VT 24/1800Z 19.7N 110.5W 85 KT

36HR VT 25/0600Z 20.4N 112.0W 85 KT

48HR VT 25/1800Z 21.1N 113.4W 70 KT

72HR VT 26/1800Z 22.6N 116.1W 40 KT...DISSIPATING

96HR VT 27/1800Z 24.5N 119.0W 25 KT...REMNANT LOW

120HR VT 28/1800Z 26.5N 122.0W 20 KT...REMNANT LOW

$$

FORECASTER STEWART