000
AXPZ20 KNHC 242204 RRA
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI MAY 24 2013
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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2145 UTC.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 09N83W TO LOW PRES NEAR 08N88W
1010 MB TO 09N95W TO 11N102W TO LOW PRES NEAR 10N106W 1009 MB TO
10N117W. ITCZ AXIS EXTENDS FROM 09N121W TO 10N140W. SCATTERED
MODERATE TO STRONG CONVECTION IS WITHIN 180 NM S OF THE AXIS
BETWEEN 86W-90W...AND FROM 09N TO 15N BETWEEN 91W-101W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM N
OF AXIS BETWEEN 91W-107W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 106W-109W.
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS
BETWEEN 123W-127W...AND ALSO WITHIN 60 NM S OF AXIS BETWEEN
132W-139W.
...DISCUSSION...
AN UPPER LEVEL TROUGH STRETCHES FROM THE FAR PACIFIC NW REGION
OF THE U.S. SW TO JUST N OF THE DISCUSSION AREA. ANOTHER UPPER
TROUGH IS OVER THE ERN PORTION OF THE AREA ALONG BAJA CALIFORNIA
...AND EXTENDS SSW TO NEAR 14N110W. UPPER LEVEL ANTICYCLONES ARE
NOTED OVER THE S CENTRAL PORTION OF THE AREA AT 12N125W...AND
OVER GUATEMALA. BROAD ANTICYCLONIC FLOW ASSOCIATED WITH THESE
ANTICYCLONES COVERS THE AREA W OF THE ERN TROUGH...AND ALSO SE
OF THE SAME TROUGH. THE ANTICYCLONIC FLOW CONTINUES TO PROVIDE A
FAVORABLE UPPER LEVEL ENVIRONMENT FOR CONVECTION ALONG AND NEAR
THE ITCZ AND MONSOON TROUGH AXIS TO CONTINUE TO REMAIN ACTIVE.
UPPER LEVEL DEBRIS CLOUDINESS FROM THIS CONVECTION IS SEEN
STREAMING NW AROUND BOTH ANTICYCLONES. THE UPPER TROUGH JUST NW
OF THE AREA IS FORECAST TO SHIFT TO THE NE AND N CENTRAL PORTIONS
BY LATE SUN INTO MON.
MODERATE SUBSIDENCE IS SEEN NOTED WITHIN ABOUT 700 NM SW OF THE
TROUGH ALONG BAJA CALIFORNIA...AND ALSO TO ITS NE. THIS IS
REFLECTED AT THE SURFACE AS A STABLE AND RATHER DRY AIR MASS
WITH ONLY STRATOCUMLUS TYPE CLOUDS NOTED TO THE N OF THE
TROPICAL REGION OF THE AREA MAINLY N OF 13N AND W OF 116W.
MOSTLY CLEAR SKIES ARE EVIDENT N OF 13N E OF 116W. THE UPPER
TROUGH WILL MOVE EWD TODAY REACHING THE NW PART OF MEXICO AS
ANOTHER AND STRONGER UPPER LEVEL TROUGH REACHES THE FAR NW
PORTION OF THE FORECAST AREA TONIGHT.
AT THE SURFACE...A 1032 MB HIGH IS ANALYZED NW OF THE AREA AT
37N143W WITH A RIDGE EXTENDING SEWD TO 32N136W TO NEAR 21N116W.
THE TIGHT PRES GRADIENT BETWEEN THE RIDGE AND LOW PRES OVER THE
WRN U.S. CONTINUES TO RESULT IN STRONG NW-N WINDS JUST N OF THE
FORECAST WATERS WITH SEAS THERE UP TO AROUND 11 FT. THE ASCAT
PASS FROM JUST PAST 18 UTC THIS AFTERNOON REVEALED NE TRADES OF
15-20 KT OVER THE WRN PORTION OF THE AREA FROM N OF THE ITCZ TO
NEAR 24N AND W OF ABOUT 128W. THE EARLIER ASCAT PASS FROM 1626
UTC THIS MORNING SHOWED SE-S WINDS OF 15-20 KT S OF THE MONSOON
TROUGH FROM NEAR 02N TO 07N AND BETWEEN 91W AND 102W. SATELLITE
IMAGERY SHOWS LOW-LEVEL CLOUD LINES ADVECTING NWD IN THIS WIND
FLOW TOWARDS THE MONSOON TROUGH AXIS. THE LOW PRES FEATURE NEAR
08N88W DESCRIBED ABOVE UNDER ITCZ/MONSOON TROUGH IS SLOWLY
GAINING LOW-LEVEL MOISTURE CONTENT IN THE MOIST SLY FLOW OF 10-
15 KT. ALTHOUGH THIS FEATURE IS EMBEDDED IN THE MONSOON
TROUGH...IT IS POSSIBLE ACCORDING TO MODEL GUIDANCE...THAT IT
MAY ATTAIN ENOUGH MOMENTUM TO SPIN UP INTO A MORE DEFINITIVE
LOW PRES SYSTEM IN THE NEAR FUTURE AS IT DRIFTS WWD. SEE LATEST
TROPICAL WEATHER OUTLOOKS FOR PROBABILITY CONDITIONS RELATING TO
THIS LOW PRES FEATURE.
STRENGTHENING HIGH PRES ACROSS THE GULF OF MEXICO WILL PRODUCE A
BRIEF GAP WIND EVENT LASTING ONLY ABOUT 6-9 HOURS ACROSS THE
GULF OF TEHUANTEPEC EARLY ON SUN WITH N WINDS OF 20-25 KT AND
SEAS TO 8 FT. NE-E WINDS ARE ALSO EXPECTED TO BRIEFLY INCREASE
TO THE RANGE OF 20-25 KT ACROSS THE GULF OF PAPAGAYO...MOST
PROBABLY ATTRIBUTED TO DEVELOPING LOW PRES ALONG OVER THE FAR
ERN PART OF THE AREA ALONG THE MONSOON TROUGH.
LONG PERIOD CROSS EQUATORIAL SW SWELLS AT 16-18 SECONDS DOMINATE
MOST OF THE FORECAST WATERS E OF 115W...WHILE LONG PERIOD MIXED
SWELLS ARE LOCATED IN THE NRN PORTION. THE SWELLS WILL CONTINUE
INTO SUN.
$$
AGUIRRE
