000
AXPZ20 KNHC 190317
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON MAR 19 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0115 UTC.

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

THE ITCZ IS S OF THE EQUATOR. THERE IS NO SIGNIFICANT DEEP 
CONVECTION IN THE FORECAST AREA ASSOCIATED WITH THE ITCZ.

...DISCUSSION...

A STRONG COLD FRONT HAS MOVED THROUGH MUCH OF BAJA CALIFORNIA 
AND SONORA MEXICO. THE OBSERVATION STATION AT HERMOSILLO MEXICO 
HAS DROPPED TO 66 DEGREES FAHRENHEIT AT 0000 UTC MON AFTER THE 
FRONTAL PASSAGE COMPARED TO 88 DEGREES AT THE SAME TIME SUN. 
INFRARED SATELLITE IMAGERY AND SOUTHWESTERN U.S. RADARS SHOW 
SCATTERED MODERATE CONVECTION OVER MUCH OF SONORA AND PORTIONS 
OF CHIHUAHUA MEXICO AS WELL AS IN THE GULF OF CALIFORNIA N OF 
26N. FRESH TO STRONG NW WINDS CAN BE FOUND ON BOTH SIDES OF THE 
BAJA PENINSULA N OF 28N. THESE WINDS MAY BE LOCALLY STRONGER AS 
THEY FUNNEL THROUGH THE MOUNTAIN PASSES IN BAJA CALIFORNIA NORTE 
INTO THE GULF OF CALIFORNIA OVERNIGHT TONIGHT. THE FRONT WILL 
RETREAT EASTWARD INTO MEXICO BY MON MORNING AND THE AREA OF 
FRESH WINDS WILL SHIFT SOUTHWARD ALONG THE BAJA PENINSULA AND 
THE MAINLAND MEXICAN COAST TO CABO CORRIENTES BY MON EVENING. 
NORTHWEST SWELL ASSOCIATED WITH THIS FRONT CONTINUES TO BRING 
SEAS AS HIGH AS 18 FEET OFF THE W COAST OF BAJA CALIFORNIA 
NORTE. THESE SEAS WILL SUBSIDE TO LESS THAN 12 FEET BY THE END 
OF THE FORECAST PERIOD ON TUE EVENING.

THE SUBTROPICAL RIDGE IS RAPIDLY FILLING IN BEHIND THIS FRONT. 
THE RIDGE STEMS FROM 1028 MB HIGH PRES NEAR 31N145W AND EXTENDS 
TO 16N105W. THIS RIDGE IS SUPPORTING A LARGE AREA OF FRESH TRADE 
WINDS TO ITS SOUTH FROM 05N TO 22N W OF 130W AND FROM 06N TO 15N 
BETWEEN 125W AND 130W ACCORDING TO THE 1844 UTC ASCAT PASS. THIS 
AREA OF TRADE WINDS WILL REMAIN RELATIVELY UNCHANGED UNTIL TUE 
WHEN THE SUBTROPICAL HIGH WILL BE WEAKENED AND PUSHED EASTWARD 
BY AN ENCROACHING COLD FRONT. THE AREA OF FRESH TRADES WILL 
EXPAND TO 130W BUT THIN OUT FROM NORTH TO SOUTH CONSIDERABLY BY 
TUE EVENING IN RESPONSE TO CHANGES IN THE SUBTROPICAL HIGH.

THE SOUTHERN STREAM UPPER JET IS FOUND ON THE LEADING EDGE OF  
BROAD DEEP-LAYER TROUGH ASSOCIATED WITH THE COLD FRONT OVER NW 
MEXICO. THE JET AXIS LIES FROM 10N120W TO NORTHEAST MEXICO. THE 
JET IS TRANSPORTING TROPICAL MOISTURE IN THE MID AND UPPER 
LEVELS THROUGH THE SOUTHERN GULF OF CALIFORNIA INTO CENTRAL 
MEXICO AND THE RIO GRANDE VALLEY. THIS MOISTURE IS MANIFESTED AS 
A BAND OF MULTI-LAYERED CLOUDS ALONG THE JET AXIS. THIS BAND OF 
CLOUDS HAS DIMINISHED SOMEWHAT SINCE YESTERDAY AS THE JET HAS 
WEAKENED. THIS TREND WILL CONTINUE THROUGH TUE AFTERNOON.

A SURFACE TROUGH LIES FROM 09N84W TO 05N87W TO 03N93W. SCATTERED 
MODERATE CONVECTION CAN BE FOUND WITHIN 210 NM SE OF THE TROUGH 
BETWEEN 84W AND 90W. THIS CONVECTION IS BEING ENHANCED BY UPPER 
LEVEL DIFFLUENCE ASSOCIATED WITH THE REAR RIGHT QUADRANT OF THE 
SOUTHWESTERLY UPPER JET OVER THE CARIBBEAN SEA.

GAP WINDS...
GULF OF PAPAGAYO...THE PRES GRADIENT BETWEEN RIDGING OVER THE NW 
CARIBBEAN AND THE AFOREMENTIONED TROUGH FROM 09N84W TO 05N87W TO 
03N93W CONTINUES TO SUPPORT FRESH NE GAP FLOW INTO THE GULF OF 
PAPAGAYO. THIS AREA OF FRESH WINDS IS EXPECTED TO DISSIPATE 
AFTER THE PERIOD OF PEAK DRAINAGE FLOW TUE MORNING AS THE 
SUPPORTING RIDGING SHIFTS NORTHEASTWARD AND THE PRES GRADIENT 
RELAXES. 
 
$$
SCHAUER