000
AXPZ20 KNHC 231537
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT OCT 23 2010

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

AXIS ANALYZED FROM 10N86W TO 11N102W TO 08N115W TO LOW PRES NEAR 
10N128W TO 06N140W. SCATTERED MODERATE CONVECTION IS N OF 04N E 
OF 81W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 180 NM N OF THE AXIS BETWEEN 130W AND 140W.

...DISCUSSION...

OVERALL TRANQUIL CONDITIONS CONTINUE TO DOMINATE MUCH OF THE 
NORTHEAST PACIFIC WITH AN ELONGATED AND NARROW HIGH PRESSURE 
RIDGE AXIS EXTENDING ALONG 24N ANCHORED BY A 1022 MB HIGH 
CENTERED NEAR 24N128W. ANTICYCLONIC SURFACE FLOW EXTENDS E TO 
105W WITH NE TRADEWINDS OF 20 KT OCCURRING ON THE SOUTHERN 
PERIPHERY OF THE HIGH W OF 128W. THE RIDGE IS FORECAST TO SHIFT 
SLIGHTLY NW OVER THE NEXT FEW DAYS...AND GRADUALLY EXPAND THE 
AREA OF 20 KT TRADES TO 21N W OF 125W. AS THE RIDGE SHIFTS NW 
AND STRENGTHENS SLIGHTLY OVER THE NW PORTION OF THE DISCUSSION 
AREA BY EARLY MON...IT IS ALSO EXPECTED TO BUILD EASTWARD ALONG 
THE BAJA CALIFORNIA COAST AND INCREASE NW WINDS TO 20 KT WITHIN 
120 NM OF THE WESTERN COAST.

TO THE SE OF THIS RIDGE...CROSS EQUATORIAL S TO SW MONSOONAL 
FLOW CONTINUES S OF 10N E OF 106W...WITH A NARROW ELONGATED ZONE 
OF 20 KT WINDS FROM 05N TO 09N BETWEEN 83W AND 95W. LOW TO 
MIDDLE LEVEL TROUGHING ACROSS THE FAR TROPICAL E PACIFIC EXTENDS 
ACROSS CENTRAL AMERICA TO A BROADER CYCLONIC GYRE ACROSS THE SW 
AND W CARIBBEAN...IN WHICH TROPICAL STORM RICHARD IS EMBEDDED. 
AS RICHARD AND THIS CYCLONIC CIRCULATION SHIFT WEST OVER THE 
NEXT COUPLE OF DAYS....THE SOUTHWESTERLY FLOW TOWARDS THE 
CENTRAL AMERICA COAST COULD BECOME ENHANCED AND TRANSPORT 
TROPICAL MOISTURE OVER PORTIONS OF WESTERN PANAMA...COSTA 
RICA...AND NICARAGUA LEADING TO PERIODS OF CONTINUED HEAVY 
RAINFALL. ALSO...GLOBAL MODELS HAVE BEEN HINTING AT THE 
POSSIBILITY OF CYCLOGENESIS IN THE VICINITY OF 10N90W THAT 
APPEARS TO REMAIN NEARLY STATIONARY AND PROVIDE FOCUS FOR 
INCREASED PRECIPITATION CHANCES THROUGH MID-WEEK BEFORE DRIFTING 
W-NW AND WEAKENING. REGARDLESS...THE MONSOONAL FLOW WILL PERSIST 
FOR A FEW MORE DAYS AND COMBINE WITH SOUTHERN HEMISPHERE SW 
SWELL TO MAINTAIN SEAS OF 8 TO 9 FT ACROSS THE WATERS E OF 
95W.   

IN THE UPPER LEVELS...A PROGRESSIVE SHORTWAVE TROUGH WAS 
OBSERVED ALONG NW MEXICO WITH AXIS EXTENDING SW TO 24N121W. 
HOWEVER...GENERALLY DRY AND STABLE ATMOSPHERIC CONDITIONS ARE 
ASSOCIATED WITH THIS UPPER LEVEL TROUGHING AND COMBINED WITH THE 
SURFACE ANTICYCLONE...THE LACK OF SIGNIFICANT SURFACE FEATURES 
OR CONVECTION IS NOTED ON SATELLITE IMAGERY N OF 12N. W AND SW 
OF THIS SHORTWAVE TROUGH WAS A TUTT LIKE TROUGH ORIENTED FROM 
21N120W TO 21N144W TO S OF HAWAII. ADVECTION OF UPPER LEVEL 
MOISTURE IS NOTED ON WATER VAPOR IMAGERY WITHIN 300 NM ON THE 
EQUATORWARD FLANK OF THE TROUGH.  ELSEWHERE...THE REGION IS 
DOMINATED AT THE UPPER LEVELS BY AN UPPER LEVEL RIDGE ALONG 14N 
E OF 136W. A SUBSIDENT ENVIRONMENT PERSISTS WITHIN THE RIDGE 
AXIS...WHILE EASTERLIES S OF THE RIDGE WERE AIDING IN 
VENTILATING ITCZ CONVECTION W OF 128W.

$$
HUFFMAN