000
AXPZ20 KNHC 071529
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON OCT 07 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...SPECIAL FEATURE...

TROPICAL STORM NARDA CENTERED AT 14.0N 122.5W AT 1500 UTC MOVING 
W OR 285 DEG AT 13 KT. MAXIMUM SUSTAINED WINDS ARE 55 KT GUSTING 
TO 65 KT WITH SURFACE PRESSURE OF 998 MB. NUMEROUS MODERATE TO  
STRONG CONVECTION ARE WITHIN 180 NM NE AND 150 NM SW 
SEMICIRCLES. NARDA IS EXPECTED TO TRACK W ALONG THE SOUTHERN 
PERIPHERY OF AN UPPER RIDGE WITH FAVORABLE UPPER LEVEL 
CONDITIONS...AND ACROSS WARM SEA WATERS...OVER THE NEXT FEW 
DAYS. THUS NARDA IS FORECAST TO INTENSIFY REACHING MINIMAL 
HURRICANE FORCE TUE AND CONTINUE AT HURRICANE FORCE THROUGH LATE 
WED. THEREAFTER...THE SEA SURFACE WATERS WILL GRADUALLY BECOME 
COOLER AND ATMOSPHERIC CONDITIONS WILL BECOME LESS FAVORABLE AND 
NARDA WILL BEGIN TO WEAKEN AND TRACK MORE NORTHWESTWARD. REFER 
TO NARDA FORECAST ADVISORY UNDER WMO/AWIPS HEADERS WTPZ24 
KNHC/MIATCMEP4 FOR ADDITIONAL DETAILS. 

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

MONSOON TROUGH 9N84W TO 10N90W TO 10N100W TO 14N114W. ITCZ  
9N134W TO 8N140W. SCATTERED MODERATE TO STRONG CONVECTION FROM 
6N-15N BETWEEN 90W-98W.
 
...DISCUSSION...

AN UPPER LEVEL TROUGH OVER THE FAR NW PORTION OF THE DISCUSSION 
AREA WITH AXIS FROM 32N135W TO 29N140W. AN UPPER LEVEL RIDGE IS 
E OF THE TROUGH FROM THE SOUTHERN TIP OF THE BAJA PENISULA N TO 
THE SW U.S. A LARGE UPPER LEVEL ANTICYCLONIC CIRCULATION IS S OF 
THE TROUGH CENTERED NEAR 17N134W. EXCEPT FOR SOME UPPER LEVEL 
MOISTURE NEAR THE COAST OF NORTHERN BAJA CALIFORNIA...MODERATE 
TO STRONG SUBSIDENCE WITH DRY AND STABLE AIR AT THE MIDDLE AND 
UPPER LEVELS IS N OF 20N W OF 105W.  AN UPPER CYCLONIC 
CIRCULATION CONTINUES OVER THE DEEP TROPICS NEAR 1N112W...WITH 
AN UPPER TROUGH EXTENDING FROM THE CYCLONIC CIRCULATION TO 5N85W.

COLD FRONT CURRENTLY MOVING INTO THE BAY OF CAMPECHE HAS 
TIGHTENED THE PRES GRADIENT ACROSS SOUTHERN MEXICO RESULTING  
NORTHERLY WINDS 20-25 KT ACROSS THE GULF OF TEHUANTEPEC. THESE 
WINDS WILL SPREAD TO AS FAR S AS 14N96W...WITH COMBINED SEAS 
BUILDING TO 8-10 FT TUE. WINDS WILL BEGIN TO DIMINISH BELOW 20 
KT LATE WED. OTHERWISE A SURFACE A RIDGE IS N OF 15N W OF 120W.

$$
DGS