000
AXPZ20 KNHC 252207
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAY 25 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...ITCZ...
AXIS IS ALONG 12N90W TO 09N100W TO 08N120W TO 08N140W. SCATTERED 
TO NUMEROUS STRONG WITHIN 120-180 NM OF THE AXIS BETWEEN 86W AND 
97W. SCATTERED MODERATE WITHIN 90 NM EITHER SIDE OF AXIS BETWEEN 
120W AND 123W...AND WITHIN 120 NM EITHER SIDE OF THE AXIS W OF 
135W.

...DISCUSSION...

FAIRLY STABLE PATTERN IN PLACE WITH A FLAT BROAD UPPER LEVEL 
TROUGH COVERING THE FAR N PORTION OF THE DISCUSSION AREA N OF A 
LINE FROM 24N140W TO 28N110W INTO EXTREME N MEXICO WITH A 400 NM 
WIDE RIBBON OF DRY AIR CUTTING THROUGH THE BASE OF THE TROUGH. 
THE SOUTHERN EDGE OF THE DRY AIR IS SITUATED TO THE N OF A 70-90 
KT SUBTROPICAL JET STREAM WHICH ENTERS THE AREA NEAR 18N140W AND 
CONTINUES ENE THROUGH 21N120W...THE SOUTHERN TIP OF BAJA 
CALIFORNIA AND INTO MEXICO. THE JET IS ADVECTING HIGH LEVEL 
MOISTURE FROM ITCZ CONVECTION FROM 120W NORTHEASTWARD INTO 
CENTRAL MEXICO.   

AN ELONGATED UPPER LEVEL RIDGE EXTENDS FROM AN ANTICYCLONIC 
CIRCULATION NEAR 12N117W TO ANOTHER CIRCULATION JUST W OF THE 
GULF OF TEHAUNTEPEC NEAR 15N98W. UPPER LEVEL DIFFLUENT FLOW TO 
THE SOUTH AWAY FROM THE RIDGE AXIS IS ENHANCING CONVECTION ALONG 
THE ITCZ BETWEEN 85W AND 102W. DIFFLUENCE ALOFT CAN ALSO BE 
FOUND BETWEEN THE E EDGE OF THE RIDGE AXIS AND THE BACK EDGE OF 
AN UPPER TROUGH SWEEPING OVER THE FAR W CARIBBEAN TO JUST E OF 
THE HONDURAS/NICARAGUA BORDER. A LOW TO MID LEVEL CYCLONIC 
CIRCULATION AND ASSOCIATED 1007 MB SURFACE LOW NEAR 11N89W 
HAS POOLED MOISTURE IN THIS REGION AND PERSISTENT SCATTERED 
MODERATE TO STRONG CONVECTION CAN CURRENTLY BE FOUND WITHIN 120 
NM OF THE COAST BETWEEN THE GULFS OF PAPAGAYO AND TEHUANTEPEC. 
THE 1544 UTC ASCAT PASS SHOWED 20-25 KT INFLOW INTO THIS BROAD 
CIRCULATION IN THE AREA FROM 04N-10N BETWEEN 85W AND 102W. 
THERE IS NOW A MODERATE PROBABILITY FOR THIS SYSTEM TO DEVELOP 
INTO A TROPICAL CYCLONE AND AS SUCH THIS FEATURE WILL BE PLACED 
IN THE SPECIAL FEATURES SECTION NEXT TWD ISSUANCE. REGARDLESS OF 
LOW DEVELOPMENT...THIS PORTION OF CENTRAL AMERICA WILL CONTINUE 
TO SEE HEAVY RAINFALL OVER THE NEXT FEW DAYS.

SURFACE RIDGE COVERS THE AREA N OF 14N W OF 110W. THE RIDGE IS 
PRODUCING A TIGHT ENOUGH PRES GRADIENT TO SUPPORT NE TO E 20-25 
KT WINDS IN AN AREA FROM 10N TO 21N W OF 125W. THE GRADIENT 
BETWEEN THE SAME RIDGE AND LOWER PRES OVER MEXICO IS PRODUCING 
20-25 KT NW WINDS ALONG THE COAST OF BAJA CALIFORNIA.THESE WINDS 
WILL BECOME CONFINED E OF 118W TO THE BAJA CALIFORNIA COAST AS 
THE RIDGE WEAKENS. A WEAK COLD FRONT IS EXPECTED TO REACH N 
WATERS WITH LITTLE FANFARE OVERNIGHT TONIGHT WITH THE MAIN 
IMPACT BEING A NEW SURGE OF NW SWELL WITH SIGNIFICANT WAVE 
HEIGHTS TO 8 FT IN NE WATERS WED.

ANOTHER TRAIN OF LONG PERIOD...17-18 SECOND...SWELLS WITH DEEP 
WATER WAVE HEIGHTS OF 7-9 FT IS CROSSING THE EQUATOR AND IS 
EXPECTED TO IMPACT THE COAST OF CENTRAL AMERICA AND MEXICO 
OVERNIGHT TUE NIGHT AND SPREAD INTO THE SRN GULF OF CALIFORNIA 
AND BAJA CALIFORNIA WED.

$$
COBB