Hurricane Advisories Hurricane advisories

000
AXPZ20 KNHC 150247
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI JUL 15 2011

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
0245 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 16N117W TO 08N131W...THEN ITCZ
AXIS THROUGH 06N140W. SCATTERED STRONG FROM 09N TO 12N E OF 82W
TO THE COAST OF COSTA RICA AND NICARAGUA. SCATTERED MODERATE
ISOLATED STRONG CONVECTION ELSEWHERE N OF 04N TO 10N BETWEEN 80W
AND 90W...AND N OF 10N TO THE COAST OF MEXICO BETWEEN 94W AND
105W.

...DISCUSSION...
E OF 110W...THE MAIN WEATHER ISSUE FOR THE NEXT 48 HOURS AND
BEYOND WILL BE THE DEVELOPMENT OF A BROAD AREA OF LOW PRES OVER
SOUTHERN CENTRAL AMERICA...WITH AN INCREASE IN MONSOONAL SW FLOW
OVER N PACIFIC WATERS E OF 105W. AN EARLIER 1552 UTC ASCAT PASS
SHOWED AN AREA OF WESTERLY 20 TO 25 KT WINDS W OF THE COAST OF
PANAMA AND A SEPARATE AREA OF SW WINDS OF 20 KT FROM 10N TO 14N
BETWEEN 95W AND 103W...INDICATING THE SW MONSOON FLOW IS
STARTING TO INCREASE IN INTENSITY AND AREAL COVERAGE. ONCE AGAIN
THE GFS AND ECMWF HAVE INITIALIZED WELL THE WESTERLY WINDS OFF
THE COAST OF PANAMA AND THE BROAD AREA OF CYCLONIC TURNING
ACROSS COSTA RICA AND PANAMA.

THE 18Z RUN OF THE GFS IS NOW COMING INTO AGREEMENT WITH THE
ECMWF AND UKMET GLOBAL MODELS IN DEVELOPING LOW PRES SYSTEM THAT
SLOWLY ORGANIZES JUST S OF THE GULF OF TEHUANTEPEC BY LATE SAT
THEN MOVES THE LOW W ON SUN. THE NOGAPS MODEL BY CONTRAST SHOWS
A MORE MODEST 20 KT SURGE OF SW TO W WINDS...AND HAS BACKED OFF
DEVELOPING LOW PRES OFF CENTRAL AMERICA AND INSTEAD IS SHOWING A
LOW ALONG THE MONSOON TROUGH OVER SOUTHERN MEXICO BY LATE SAT.

FURTHER EAST...THE GFS REMAINS THE AGGRESSIVE OUTLIER IN
DEPICTING SW TO W WINDS OF 20 TO 30 KT FUNNELING INTO THE COAST
OF PANAMA AND COSTA RICA WITH THE GFS DRIVEN WAVE WATCH MODEL
BUILDING SEAS TO 12-14 FT. WAVE WATCH IS TOO HIGH THUS WILL
FORECAST TO BUILD E OF 90W TO AS HIGH AS 12 FT WITH THE
INCREASED S AND SW FLOW. THESE WINDS FEED INTO ANOTHER BROAD
LOW ORGANIZING OVER PANAMA BY LATE SAT INTO SUN. GIVEN THE
COMPLEX FLOW AND THE AS YET DEVELOPED LOW PRES AREAS THE HIGH
SEAS IS A FAIRLY LOW CONFIDENCE FORECAST AND CONSISTS OF A BLEND
OF THE GFS/UKMET/ECMWF MODELS FOR THE LOW S OF THE TEHUANTEPEC.

MEANWHILE...CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION
PERSIST ALONG MONSOON TROUGH JUST INLAND ALONG THE CENTRAL
AMERICAN COASTLINE IN ADDITION THE CONVERGENCE OF THE INCREASED
SW TO W FLOW IS AIDING DEVELOPMENT OF CONVECTION OVER THE OPEN
PACIFIC FROM 04N TO 10N BETWEEN 80W AND 92W. THE PERSISTENT
CONVECTION SHOULD RESULT IN LOCALLY HEAVY RAINFALL AND THE
POTENTIAL FOR LIFE THREATENING FLASH FLOODS AND MUDSLIDES INTO
THE WEEKEND. ADDITIONAL INFORMATION IS CONTAINED IN THE
GRAPHICAST AT ://WWW.HURRICANES.GOV/MARINE.

W OF 110W...ASCAT AND SHIP DATA SHOW FRESH NW FLOW ALONG THE
COAST OF BAJA PERSISTING BETWEEN 1037 MB HIGH PRES NEAR
43N155W...AND TROUGHING OVER THE GULF OF CALIFORNIA...AND THIS
SHOULD PERSIST THROUGH 48 HOURS WITH NW WINDS DEVELOPING OVER
THE GULF OF CALIFORNIA WITHIN 24 HOURS. FURTHER SOUTH...TRADE
WINDS REMAIN ANOMALOUSLY LIGHT.

$$
COBB