000
AXPZ20 KNHC 200917
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JUN 20 2012

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 
0900 UTC.

...SPECIAL FEATURES...
A 1005 MB LOW PRES IS CENTERED NEAR 18N108W. THE LOW REMAINS 
EXPOSED DUE TO MODERATE NE WIND SHEAR ALOFT. SCATTERED MODERATE 
CONVECTION IS WITHIN 70 NM OF THE LOW IN THE SW QUADRANT. 
CONVECTION DIRECTLY ASSOCIATED WITH THE LOW HAS DIMINISHED BOTH 
IN AREAL AND INTENSITY COVERAGE. THIS SYSTEM NOW HAS A MEDIUM 
CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS 
AS IT REMAINS NEARLY STATIONARY. DEEP TROPICAL MOISTURE MOSTLY 
ASSOCIATED WITH THE MONSOON TROUGH TO THE SE OF THE LOW IS BEING 
ADVECTED ENE TOWARDS SRN MEXICO. THIS MOSITURE WILL CONTINUE TO 
BRING LOCALLY HEAVY RAINFALL PRIMARILY ALONG THE SOUTHERN COAST 
OF MEXICO DURING THE NEXT 48 HRS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON FROM TROUGH 1005 MB LOW NEAR 18N108W TO 10N123W. THE 
ITCZ FROM 10N123W TO 06N140W. SCATTERED MODERATE ISOLATED STRONG 
WITHIN 120 NM S OF LINE 18N103W TO 11N115W.

...DISCUSSION...
UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION NEAR 
31N136W TO 20N138W. A 90-95 KT SLY JETSTREAM E OF THE TROUGH 
FROM 26N132W TO 32N131W. UPPER LEVEL ANTICYCLONIC CIRCULATION W 
OF BAJA CALIFORNIA NEAR 25N118W WITH RIDGE N ACROSS THE NORTHERN 
BAJA PENINSULA. ANOTHER RIDGE EXTENDS SW OF THE ANTICYCLONE TO 
9N130W. SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER 
LEVELS IS N OF 20N W OF 110W.

SURFACE TROUGH FROM 31N134W TO 21N140W. PRES GRADIENT BETWEEN 
HIGH PRES NW OF THE AREA AND THE TROUGH IS PRODUCING NE WINDS 20 
KT NW OF THE TROUGH. THE TROUGH IS FORECAST TO DISSIPATE IN 24 
HOURS AND WINDS WILL DECREASE TO LESS THAN 20 KT.

PRES GRADIENT OFF THE COAST OF BAJA CALIFORNIA REMAINS TIGHT 
ENOUGH FOR 20 KT NW WINDS N OF 24N E OF 120W TO THE COAST OF 
BAJA CALIFORNIA. THESE WINDS ARE FORECAST TO CONTINUE THROUGH 
THE NEXT 48 HOURS.

CROSS EQUATORIAL SE SWELL IS S OF 5N BETWEEN 105W-125W. THE AREA 
WILL EXPAND SOME LATER TODAY AND TONIGHT.

$$
DGS