je.st
news
Tropical Storm NARDA Forecast Discussion Number 7
2013-10-08 10:41:03| National Hurricane Center (East Pacific)
Issued at 200 AM PDT TUE OCT 08 2013 000 WTPZ44 KNHC 080840 TCDEP4 TROPICAL STORM NARDA DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP142013 200 AM PDT TUE OCT 08 2013 A SERIES OF RECENT MICROWAVE IMAGES INDICATE THAT THE LOW-LEVEL CENTER OF NARDA IS LOCATED ON THE NORTHEASTERN EDGE OF A SMALL AREA OF DEEP CONVECTION. DVORAK CURRENT INTENSITY ESTIMATES ARE STILL 55 KT FROM TAFB AND SAB...ALTHOUGH THE FINAL T-NUMBER FROM SAB HAS FALLEN TO 35 KT. IN ADDITION...THE LATEST OBJECTIVE ADT AND SATCON ESTIMATES FROM THE UNIVERSITY OF WISCONSIN ARE AROUND 45 KT. BASED ON THESE NUMBERS...THE INITIAL INTENSITY IS LOWERED TO 50 KT...BUT THIS COULD STILL BE A LITTLE GENEROUS. A SIGNIFICANT CHANGE TO THE INTENSITY FORECAST WAS REQUIRED IN THIS ADVISORY. ALTHOUGH DEEP-LAYER SHEAR IS EXPECTED TO BE LOW FOR ANOTHER 36 HOURS...NARDA APPEARS TO BE STRUGGLING A BIT DUE TO A MARGINAL THERMODYNAMIC ENVIRONMENT. AS THE STORM CONTINUES WESTWARD...IT WILL BE RUNNING INTO AN EVEN DRIER AND MORE STABLE AIR MASS...AND THE PROSPECTS FOR FURTHER INTENSIFICATION HAVE DECREASED SIGNIFICANTLY. IN ADDITION...THE GLOBAL MODELS INDICATE THAT A MID-LEVEL BLOCKING RIDGE WILL DEVELOP TO THE WEST OF NARDA IN ABOUT 48 HOURS AND CAUSE THE LOW- AND MID-LEVEL CIRCULATIONS TO DECOUPLE. AS A RESULT...THE INTENSITY GUIDANCE NO LONGER SHOWS ANY STRENGTHENING. THE UPDATED NHC INTENSITY FORECAST MAINTAINS AN INTENSITY OF 50 KT FOR THE NEXT 24 HOURS WHILE THE VERTICAL SHEAR REMAINS LOW...BUT THEN SHOWS RELATIVELY FAST WEAKENING TO REMNANT LOW STATUS BY DAY 4. NARDA IS LOCATED TO THE SOUTH OF A WEAKENING MID-LEVEL RIDGE...AND ITS CURRENT MOTION IS 290/11 KT. A MID- TO UPPER-LEVEL TROUGH IS FORECAST TO AMPLIFY ALONG THE U.S. WEST COAST OVER THE NEXT COUPLE OF DAYS...LEAVING NARDA IN A COL REGION TO THE SOUTH OF THE TROUGH AND BETWEEN TWO MID-LEVEL ANTICYCLONES TO ITS EAST AND WEST. THE LACK OF SIGNIFICANT STEERING FLOW WILL CAUSE THE CYCLONE TO SLOW DOWN AND LIKELY DRIFT WESTWARD BY 48 AND 72 HOURS. AFTER THAT TIME...NARDA WILL BE WEAKENING...AND THE REMNANT LOW SHOULD ACCELERATE WESTWARD WITHIN THE TRADES BY DAYS 4 AND 5. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 15.3N 125.4W 50 KT 60 MPH 12H 08/1800Z 15.7N 126.9W 50 KT 60 MPH 24H 09/0600Z 16.1N 128.3W 50 KT 60 MPH 36H 09/1800Z 16.3N 129.2W 45 KT 50 MPH 48H 10/0600Z 16.3N 129.7W 40 KT 45 MPH 72H 11/0600Z 16.3N 130.6W 30 KT 35 MPH 96H 12/0600Z 16.0N 132.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 13/0600Z 15.5N 135.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ FORECASTER BERG
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics