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000
AXPZ20 KNHC 280250
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON JUL 28 2014

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC.


...SPECIAL FEATURES... HURRICANE HERNAN IS CENTERED NEAR 19.3N 113.1W AT 28/0300 UTC OR ABOUT 280 NM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING NW AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. SCATTERED TO NUMEROUS MODERATE CONVECTION IS WITHIN 60 NM OF CENTER. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 17N TO 21N BETWEEN 110W AND 114W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS.


...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 08N96W TO 16N96W MOVING E AT 15-20 KT. SCATTERED MODERATE CONVECTION IS FROM 10N TO 14N BETWEEN 94W AND 99W.


...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N78W TO 09N85W TO 07N95W TO 07N103W TO 10N109W THEN RESUMES FROM 15N116W TO 1010 MB LOW PRES NEAR 12N122W TO 14N129W. THE INTERTROPICAL CONVERGENCE ZONE AXIS IS FROM 13N135W TO 13N140W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 06N TO 08N BETWEEN 89W AND 96W...FROM 06N TO 12N BETWEEN 105W AND 109W...AND FROM 10N TO 16N BETWEEN 121W AND 125W.


...DISCUSSION... AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY WITH AXIS EXTENDING FROM 32N130W TO A BASE NEAR 15N130W. MOSTLY DRY AIR ACCOMPANIES THIS TROUGHING GENERALLY N OF 16N BETWEEN 126W AND 137W. A 1007 MB LOW CENTERED NEAR 14N133W REMAINS JUST WEST OF THE BASE OF THE TROUGH WITH MOST OF THE CONVECTION ASSOCIATED WITH THE LOW OCCURRING TO THE EAST LEAVING THE LOW-LEVEL CIRCULATION CENTER EXPOSED. AS THE LLCC MOVES WEST DURING THE NEXT 24 HOURS...THE UPPER LEVEL ENVIRONMENT BECOMES TO HOSTILE TO SUPPORT ANY ORGANIZED CONVECTION. HOWEVER...AN AREA OF FRESH TO STRONG WINDS WITH SEAS TO 11 FT IS FORECAST TO ACCOMPANY THIS SYSTEM DURING THE NEXT 48 HOURS. FARTHER EAST...A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER NORTH TEXAS WITH A NARROWING RIDGE OVER NORTHERN MEXICO THAT TIES IN WITH ANOTHER ANTICYCLONE CENTERED IN THE VICINITY OF HURRICANE HERNAN NEAR 21N110W. THIS UPPER LEVEL FEATURE IS PROVIDING A FAVORABLE ENVIRONMENT ALOFT FOR HERNAN AS THE CYCLONE IS FORECAST TO MAINTAIN HURRICANE INTENSITY THROUGH THE OVERNIGHT HOURS. THEREAFTER...INCREASING WESTERLY SHEAR AND COOLER WATERS ARE EXPECTED TO TAKE THEIR TOLL ON HERNAN AS THE SYSTEM BEGINS A GRADUALLY WEAKENING TREND MONDAY THROUGH WEDNESDAY.

EXPECT WINDS TO PULSE UP TO A RANGE OF 15 TO 20 KT WITH SEAS TO 7 FT ACROSS THE GULF OF PAPAGAYO DURING THE EARLY MORNING HOURS WITH THE AID OF NOCTURNAL DRAINAGE FLOW. IN ADDITION...BY EARLY TUE...N WINDS IN THE RANGE OF 20 TO 25 KT WILL OCCUR BRIEFLY IN THE GULF OF TEHUANTEPEC BUILDING SEAS TO 9 FT. CONDITIONS ARE EXPECTED TO IMPROVE BY LATE TUE.

OTHERWISE...A SURFACE RIDGE DOMINATES THE REMAINDER OF THE AREA N OF 20N W OF 117W. FINALLY...SE SWELL FROM THE SOUTHERN HEMISPHERE CONTINUES TO IMPACT THE SOUTH-CENTRAL WATERS... GENERALLY S OF 01N BETWEEN 103W AND 120W. THIS SWELL EVENT WILL CONTINUE TO PROPAGATE FARTHER WEST ACROSS THE FORECAST REGION.

$$ HUFFMAN

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