000
AXPZ20 KNHC 161558
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 UTC WED OCT 16 2013

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURES...

THE CENTER OF TROPICAL DEPRESSION PRISCILLA AT 16/1500 UTC IS 
NEAR 18.1N 119.3W...OR ABOUT 600 NM TO THE WEST-SOUTHWEST OF THE 
SOUTHERN TIP OF BAJA CALIFORNIA. PRISCILLA IS MOVING WEST-
NORTHWESTWARD 7 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 
1007 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 30 KT WITH GUSTS 
TO 40 KT. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. 
CONVECTIVE PRECIPITATION...SCATTERED MODERATE ISOLATED STRONG 
FROM 17N TO 20N BETWEEN 119W AND 121W. PRISCILLA IS FORECAST TO 
BECOME A REMNANT LOW AT 48 HOURS AND AT 72 HOURS INTO THE 
FORECAST PERIOD. IT WILL BE DISSIPATED ANOTHER 24 HOURS OR SO 
LATER. PRISCILLA IS GOING TO BE MOVING INTO AN AREA OF DRIER AND 
MORE STABLE AIR...COLDER SEA SURFACE TEMPERATURES... AND 
INCREASING WIND SHEAR ALOFT. 

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

THE MONSOON TROUGH PASSES THROUGH COSTA RICA NEAR 11N84W TO 
09N100W...TO A 1011 LOW PRESSURE CENTER THAT IS NEAR 09N111W... 
TO 10N120W TO 10N133W TO 08N138W. THE ITCZ CONTINUES FROM 
08N138W BEYOND 08N140W. CONVECTIVE PRECIPITATION...SCATTERED 
MODERATE TO ISOLATED STRONG FROM 6N TO 08N BETWEEN 90W AND 
97W... FROM 08N TO 09N BETWEEN 105W AND 107W...FROM 10N TO 12N 
BETWEEN 109W AND 110W...FROM 08N TO 09N BETWEEN 111W AND 
113W...AND FROM 07N TO 10N BETWEEN 123W AND 138W. SCATTERED 
MODERATE ISOLATED STRONG FROM 19N TO 21N BETWEEN 105W AND 106W.

...DISCUSSION...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH IS JUST TO THE WEST OF THE 
AREA. MIDDLE LEVEL TO UPPER LEVEL SOUTHWESTERLY WIND FLOW COVERS 
THE AREA THAT IS TO THE NORTH OF 17N TO THE WEST OF 135W. 
TROPICAL MOISTURE IS MOVING NORTHEASTWARD WITH THE SOUTHWESTERLY 
WIND FLOW. 

COMPARATIVELY DRIER AIR IN SUBSIDENCE...AS SEEN IN WATER VAPOR 
IMAGERY...COVERS THE EASTERN PACIFIC OCEAN THAT IS TO THE SOUTH 
OF 23N TO THE WEST OF TROPICAL DEPRESSION PRISCILLA. 
 
A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH COLORADO... 
ARIZONA...SOUTHERN CALIFORNIA/THE NORTHWESTERN CORNER OF 
MEXICO...TO 28N125W IN THE EASTERN PACIFIC OCEAN. 

A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH IS ALONG 10N114W 
14N110W 18N108W 22N108W. THIS TROUGH IS ABOUT 600 NM TO THE EAST 
OF TROPICAL DEPRESSION PRISCILLA. 

A 1011 MB LOW PRESSURE IS IN THE MONSOON TROUGH NEAR 9N111W. 
CONVECTIVE PRECIPITATION...THE WIND SPEEDS ARE LIGHT TO 
MODERATE. THE SEA HEIGHTS RANGE FROM 4 TO 6 FEET. NO DEVELOPMENT 
OF THIS LOW CENTER IS ANTICIPATED DURING THE NEXT 48 HOURS AS IT 
CONTINUES MOVING WESTWARD FROM 5 TO 10 KNOTS.

A TROPICAL WAVE IS ALONG 14N91W 11N89W 8N87W. SCATTERED MODERATE 
ISOLATED STRONG FROM 8N TO 12N BETWEEN 88W AND 91W.

A SURFACE RIDGE PASSES THROUGH 32N137W TO 24N131W AND 14N131W.

RELATIVELY BENIGN MARINE CONDITIONS PREVAIL OUTSIDE OF THE 
EFFECTS OF PRISCILLA. LIGHT TO MODERATE WINDS AND 4 FOOT TO 7 
FOOT SEAS DOMINATE THE DISCUSSION WATERS THROUGHOUT AT LEAST THE 
NEXT 48 HOURS. ONE OF THE MAIN EXCEPTIONS WILL BE IN THE GULF OF 
CALIFORNIA WHERE WINDS WILL INCREASE OCCASIONALLY TO MODERATE TO 
FRESH LEVELS AS THE PRESSURE GRADIENT THAT IS ACROSS THAT REGION 
FLUCTUATES. A SECOND EXCEPTION WILL BE IN THE FAR WEST CENTRAL 
WATERS TO THE NORTH OF THE MONSOON TROUGH/ITCZ...WHERE MODERATE 
TO FRESH WINDS WILL BE ASSOCIATED WITH A WEAK SURFACE TROUGH.

$$
MT