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AXPZ20 KNHC 010945
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT AUG 01 2015

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC.


...SPECIAL FEATURES...

AT 0900 UTC AUG 01...THE CENTER OF HURRICANE GUILLERMO WAS NEAR 13.4N 137.4W OR ABOUT 1250 MI ESE OF HILO HAWAII. GUILLERMO WAS MOVING W-NW OR 285 DEG AT 14 KT AND IS FORECAST TO SLOW ITS FORWARD MOTION TONIGHT. THE MINIMUM CENTRAL PRESSURE WAS ESTIMATED AT 970 MB. MAXIMUM SUSTAINED ARE 90 KT WITH GUSTS TO 110 KT. DRY AIR HAS ENTRAINED INTO THE W SEMICIRCLE AND GUILLERMO HAS BECOME LESS ORGANIZED OVER THE PAST FEW HOURS. NUMEROUS STRONG CONVECTION IS CURRENTLY OBSERVED WITHIN 90 NM OF CENTER SURROUNDED BY SCATTERED MODERATE TO STRONG CONVECTION WHICH IS NOTED ELSEWHERE WITHIN 150 NM EITHER SIDE OF A LINE FROM 14N132W TO 13N140W. GUILLERMO WILL CONTINUE TO EXPERIENCE SOMEWHAT FAVORABLE ATMOSPHERIC AND OCEANIC ENVIRONMENT TODAY... THEREAFTER SEA SURFACE TEMPERATURES WILL BE COOLER. GUILLERMO IS FORECAST TO CHANGE LITTLE TODAY THEN A BEGIN TO WEAKEN. REFER TO THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMEP4/WTPZ24 KNHC FOR ADDITIONAL DETAILS.


...TROPICAL WAVES...

TWO TROPICAL WAVE S HAVE MERGE INTO A SINGLE WAVE ANALYZED FROM 06-16N ALONG 107W. ISOLATED MODERATE AND STRONG CONVECTION IS NOTED WITHIN 120 NM OF WAVE AXIS. A SURFACE LOW IS EXPECTED TO DEVELOP ALONG THE WAVE NEAR 10N LATE SUN AND CONTINUE W WHILE THE WAVE LOSES IDENTITY.


...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

A MONSOON TROUGH EXTENDS SW OFF THE PACIFIC COAST OF COLOMBIA 07N78W TO 07N80W THEN TURNS NW TO 09N98W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ WHICH CONTINUES NW TO 10N102W...THEN TURN SW TO 07N132W WHERE IT LOSES IDENTITY. EXCEPT AS PREVIOUSLY DESCRIBED NEAR GUILLERMO AND THE TROPICAL WAVE...SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED TO THE N OF 02N E OF 81W. SIMILAR CONVECTION IS OBSERVED WITHIN 120 NM EITHER SIDE OF A LINE FROM 06N90W TO 11N100W AND A LINE FROM 06N110W TO 11N115W.


.SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ALSO OBSERVED WITHIN 90 NM OF THE PACIFIC COAST OF MEXICO FROM 16-27N.


...DISCUSSION...

A 1018 MB SURFACE HIGH IS MEANDERING NEAR 28N127W WITH A RIDGE EXTENDING SE TO NEAR 18N112W. ALTHOUGH THE GFS GUIDANCE HAS BACKED OFF A LITTLE ON THE NW FLOW INCREASING TO 15-20 KT WITHIN 150 NM OF THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA LATER TODAY...THE EUROPEAN GUIDANCE STILLS SUGGESTS 20 KT CONDITIONS. ASSOCIATED SEAS OF 4-7 FT EARLY TODAY ARE EXPECTED TO GRADUALLY BUILD TO 5-8 FT BY THIS EVENING AND CONTINUE THROUGH EARLY NEXT WEEK.

CROSS-EQUATORIAL SWELL WITH COMBINED SEAS OF 7-8 FT WILL CONTINUE TO PROPAGATE N ACROSS THE TROPICS S OF 12N BETWEEN 95- 130W TODAY AND SUN...THEN BEGIN TO SUBSIDE.

GULF OF PAPAGAYO...EXPECT MAXIMUM DRAINAGE OF ONLY 15-20 KT AT SUNRISE TODAY AND THEN AGAIN ON SUN NIGHT RESULTING IN AN AREA OF 7-8 FT SEAS PROPAGATING W-SW AND MIXING WITH THE LONG PERIOD CROSS EQUATORIAL SWELL. GUIDANCE IS SUGGESTING THAT THE DRAINAGE WILL INCREASE TO 20-25 KT ON MON NIGHT.

GULF OF TEHUANTEPEC...EXPECT 15-20 KT DRAINAGE WITH SEAS OF 5-8 FT ON TUE NIGHT INTO WED.

$$ NELSON

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