000
AXPZ20 KNHC 201019
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE MAR 20 2007

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.

...ITCZ...
ITCZ IS CENTERED ALONG...3N78W 4N85W 5N91W 4N106W 5N125W 5N130W
3N140W. SCATTERED STRONG CONVECTION IS WITHIN 30 NM EITHER SIDE
OF THE AXIS BETWEEN 135W-137W.

...DISCUSSION...

MID TO UPPER LEVEL TROUGH ENTERING NW PORTION OF AREA EXTENDS
FROM 32N130W SW TO 24N140W. BROAD UPPER LEVEL ANTICYCLONIC FLOW 
COVERS MUCH OF THE AREA ELSEWHERE SE OF THE TROUGH TO 110W. A
JET STREAM BRANCH WITH MAXIMUM WINDS OF 70-90 ENTERS THE REGION 
THROUGH 17N140W AND CONTINUES NEWD AROUND THE NRN PERIPHERY OF 
THE RIDGE TOWARDS NRN BAJA CALIFORNIA. SATELLITE WATER VAPOR 
IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE AND DRY AIR BETWEEN 
THE JET STREAM AND TROUGH. THE TROUGH IS FORECAST TO RAPIDLY 
MOVE E THROUGH THU AS A MID/UPPER CYCLONIC CIRCULATION DEVELOPS 
OVER THE FAR NE PART OF THE AREA NEAR NRN BAJA CALIFORNIA BY 
EARLY THU MORNING. A SHORTWAVE TROUGH IS EMBEDDED WITHIN THE 
ANTICYCLONIC AREA FROM 10N124W 2N127W. THIS TROUGH IS FORECAST 
TO SLOWLY MOVE E AND BECOME DIFFUSE OVER THE NEXT 3 DAYS.

OVER THE E PORTION OF THE DISCUSSION AREA...A MID/UPPER LEVEL 
TROUGH EXTENDS FROM THE SW GULF OF MEXICO SW THROUGH 18N96W TO 
NEAR 4N110W. MID/UPPER LEVEL RIDGING EXTENDING E TO W ACROSS S 
AMERICA ALONG 7N W TO 87W REMAINS RATHER DOMINANT OVER THAT 
REGION. CONFLUENT BETWEEN THIS RIDGE AND TROUGH IS RESULTING IN 
MODERATE SUBSIDENCE AND ASSOCIATED DRY AIR E OF 110W. ITCZ 
CONVECTION HERE REMAINS VERY ISOLATED WITH ONLY ISOLATED 
MODERATE BETWEEN 91W-94W.

AT THE SURFACE...RIDGE EXTENDS SE INTO THE AREA THROUGH 32N140W
26N126.5W TO 21N113W. A WEAKENING COLD FRONT MOVING E 15 KT 
EXTENDS FROM 32N127W TO 26N131W. SCATTERED TO BROKEN LOW CLOUDS 
WITH ISOLATED SHOWERS ARE WITHIN 60-90 NM OF THE FRONT MAINLY N 
OF 28N. ELSEWHERE ...HIGH PRES COVERS THE AREA N OF 14N W OF 
113W.

GAP WINDS...GULF OF TEHUANTEPEC REMAINS QUIET WITH WINDS LESS 
THAN 20 KT. WINDS SHOULD BRIEFLY INCREASE TO 20 KT BY TUE 
NIGHT...THEN DECREASE ONCE AGAIN WED NIGHT. TIGHT PRES GRADIENT 
OVER THE CARIBBEAN IS RESULTING IN MODERATE ELY FLOW OVER THE SW 
CARIBBEAN. THIS FLOW PATTERN IS SPILLING OVER INTO THE E PACIFIC 
ACROSS CENTRAL AMERICA PRODUCING NE 20-25 KT WINDS IN THE GULF 
OF PAPAGAYO. LATEST MODEL GUIDANCE INDICATES THAT THESE WINDS 
WILL CONTINUE THROUGH AT LEAST EARLY ON SAT.

$$
AGUIRRE