Tropical Weather Discussion
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000
AXPZ20 KNHC 281605
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE JUL 28 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1545 UTC.

...SPECIAL FEATURE...

TROPICAL DEPRESSION EIGHT-E IS CENTERED NEAR 16.4N 129.1W 1007
MB AT 1500 UTC JUL 28 MOVING WNW OR 285 DEG AT 11 KT. MAXIMUM
SUSTAINED WINDS 30 KT GUSTS 40 KT. DEEP CONVECTION...WITH VERY
COLD TOPS...HAS INCREASED OVER AND WITHIN 75 NM OF THE CENTER IN
THE SE QUADRANT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS ELSEWHERE WITHIN 120 NM OF THE CENTER IN THE SE QUADRANT...
AND ALSO WITHIN 45 NM OF 12N127W. THE LATEST NHC ADVISORY
FORECASTS THE DEPRESSION TO ATTAIN MINIMAL TROPICAL STORM
STRENGTHEN NEAR 16.7N130.9W TONIGHT...AND AS IT REACHES NEAR
17.0N133.2W EARLY ON WED BEFORE IT WEAKENS BACK TO A DEPRESSION
BY EARLY WED EVENING. SEE THE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADER MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

THE SOUTHERN PORTION OF TROPICAL WAVE AXIS EXTENDS FROM HONDURAS
S TO 10N ALONG 86W MOVING W AT 15-20 KT. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS JUST S OF THE WAVE MAINLY
ASSOCIATED WITH THE MONSOON TROUGH AS DESCRIBED BELOW.

A TROPICAL WAVE AXIS IS ALONG 112W FROM 09N-17N MOVING W NEAR 13
KT. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM W OF WAVE FROM
10N TO 13N. THIS WAVE IS ENTERING THE EASTERN PORTION OF A BROAD
CYCLONIC GYRE ASSOCIATED WITH A LOW PRES SYSTEM NEAR 07N117.5W.

A TROPICAL WAVE AXIS IS ALONG 136W FROM 10N-17N MOVING W 15-20
KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN
120 NM W OF THE WAVE FROM 11N-15N.

BROAD LOW PRES NEAR 08.5N116.5W 1008 MB WAS EMBEDDED WITHIN THE
MONSOON TROUGH...AND ALSO ASSOCIATED WITH A TROPICAL
WAVE...MOVING W 15-20 KT. BANDS AND LINES OF SCATTERED MODERATE
TO STRONG CONVECTION WERE OCCURRING AROUND THE PERIPHERY OF THIS
CIRCULATION...WITHIN 270 NM ACROSS THE NE AND 300 NM SW
SEMICIRCLES. THIS LOW PRES AREA HAS THE POTENTIAL TO GRADUALLY
BECOME BETTER ORGANIZED OVER THE NEXT SEVERAL DAYS AS IT
CONTINUES MOVING W.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM 07N78W TO 09N88W TO 08N99W
TO 09N111W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS
SEEN FROM 02N-07N BETWEEN 78W-81W...WITHIN 90 NM N OF THE
THROUGH BETWEEN 81W-86W...WITHIN 60 NM N OF THE TROUGH BETWEEN
86W-90W...WITHIN 60 NM S OF THE TROUGH BETWEEN 100W-102W AND
WITHIN 180 NM N OF THE TROUGH BETWEEN 109W-111W.

...DISCUSSION...

A 1029 MB HIGH PRES CENTER IS ANALYZED WELL N OF THE AREA NEAR
44N136W WITH A RIDGE EXTENDING SE TO 32N132W TO NEAR 23N119W.
HIGH PRES COVERS THE AREA N OF 23N W OF 119W. THE PRES GRADIENT
BETWEEN THE RIDGE AND THE TYPICAL TROUGH SEEN ALONG BAJA
CALIFORNIA IS HELPING TO INDUCE NW WINDS OF 15-20 KT WITHIN
ABOUT 180 NM W OF THE BAJA CALIFORNIA PENINSULA WITH RESULTANT
SEAS OF 6-8 FT. THE GRADIENT IS FORECAST TO LET UP JUST ENOUGH
BY WED AFTERNOON TO ALLOW THESE WINDS TO DIMINISH TO 10-15 KT
WITH SEAS LOWERING TO AROUND 5-6 FT.

THE PRES GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND LOWER PRES
IN THE TROPICAL REGION IS ALLOWING FOR MODERATE TO FRESH TRADE
WINDS TO EXIST OVER THE WESTERN PORTION OF THE AREA FROM 13N-19N
W OF 133W. THESE WINDS WILL BE REPLACED BY STRONGER WINDS ON THE
PERIPHERY OF THE DEPRESSION AS IT TRACKS WNW WHILE STRENGTHENING
TO A TROPICAL STORM. PRESENT SEAS OF 6-8 FT THERE ARE EXPECTED
TO BUILD TO HIGHER RANGES AS WELL WITH THE APPROACH OF CURRENT
TROPICAL SYSTEM.

GAP WINDS...
GULF OF PAPAGAYO...STRONG TRADE WINDS FROM THE SOUTHERN
CARIBBEAN CONTINUE TO FUNNEL ACROSS THE HIGHER TERRAIN OF
CENTRAL AMERICA. THE ADDED INGREDIENT OF NOCTURNAL DRAINAGE FLOW
HAS HELPED TO SURGE THESE WINDS OUT TO THE PACIFIC WATERS NEAR
88W FROM 10N-11 INCLUDING THE GULF. THESE WINDS WILL DIMINISH TO
15-20 BY EARLY THIS EVENING...THEN MATERIALIZE AGAIN LATE
TONIGHT BEFORE DIMINISHING AGAIN WED AFTERNOON. RESIDUAL MIXED
NE AND SWELLS WILL PRODUCE SEAS TO 9 FT AT THAT TIME FROM 08N-
11N BETWEEN 89W-93W...AND ALSO WITHIN 30 NM OF A LINE FROM
11N86W TO 10N89W. THIS SWELL AREA IS EXPECTED TO SHRINK
BY EARLY ON THU.

$$
AGUIRRE


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