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000
AXPZ20 KNHC 221611
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON DEC 22 2014

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.


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

THE MONSOON TROUGH AXIS EXTENDS FROM 04N77W TO 06N91W TO 07N103W. ITCZ EXTENDS FROM 07N103W TO 08N112W TO 06N125W TO 07N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE ITCZ BETWEEN 107W-112W...AND ALSO WITHIN 30 NM OF THE ITCZ BETWEEN 112W-122W.


...DISCUSSION...

UPPER LEVELS...THE FLOW AROUND A LARGE ANTICYCLONE CENTERED AT 30.5N129W DOMINATES THE AREA W OF ABOUT 111W. TO ITS E...A SHARP UPPER TROUGH STRETCHES SW FROM CENTRAL U.S. TO JUST S OF BAJA CALIFORNIA AND TO 15N119W. A RATHER PROMINENT SUBTROPICAL JET STREAM BRANCH EXTENDS FROM THE CENTRAL DEEP TROPICS ENE THROUGH 19N140W...AND DIVES SEWD TO ROUND THE BASE OF THE UPPER TROUGH THEN NE TO ACROSS CENTRAL CENTRAL MEXICO. AMPLE DEEP TROPICAL MOISTURE IS BEING CHANNELED EASTWARD ALONG THIS JET STREAM. THIS MOISTURE REACHES AS FAR NE AS CENTRAL MEXICO FROM 15N TO 20N... AND THEN CONTINUES NEWD TO ACROSS MUCH OF THE GULF OF MEXICO. SATELLITE IMAGERY SUGGEST TRANSVERSE BANDING ALONG...AND WITHIN 10 DEG S OF THE JETSTREAM BRANCH W OF 120W. MODERATE SUBSIDENCE IS PREVALENT N OF THE AFOREMENTIONED JET STREAM. THIS IS MAINTAINING DRY AND SINKING AIR OVER THAT PART OF THE AREA.

AT THE SURFACE...A 1029 MB HIGH PRES CENTER IS LOCATED JUST N OF THE AREA NEAR 34N132W WITH A RIDGE AXIS EXTENDING SE THROUGH 30N127W TO 15N103W. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES ASSOCIATED WITH THE ITCZ TO THE S IS MAINTAINING A SMALL AREA OF 20-25 KT N WINDS ACROSS THE SUB-TROPICAL WATERS N OF 25N BETWEEN 120W-125W. THESE CONDITIONS ARE EXPECTED TO LAST INTO EARLY TUE MORNING BEFORE DIMINISHING TO BELOW 20 KT.

A WEAK SURFACE TROUGH IS ALONG 111W FROM 05N TO 11N. SCATTERED MODERATE CONVECTION EXISTS FROM 10N TO 14N BETWEEN 108W AND 111W. NE-E 15-20 KT TRADES ARE OBSERVED ACROSS THE TROPICS BETWEEN THE ITCZ AND THE RIDGE WITH AN AREA OF EMBEDDED 20-25 KT NE WINDS WITH SEAS OF 10-13 FT PRIMARILY IN NW SWELL OVER THE WATERS FROM 07-18N W OF 125W. THE GRADIENT IS ALREADY RELAXING AND THE AREA OF 20-25 KT CONDITIONS WILL SHRINK THROUGH THE REST OF TODAY WITH THESE WINDS DIMINISHING TO BELOW 20 KT.

OTHERWISE...LONG PERIOD NW SWELLS WILL CONTINUE TO SPREAD EASTWARD ACROSS THE DISCUSSION AREA W OF 100W WITH RESULTANT COMBINED SEAS OF 8-12 FT. THESE SWELLS WILL GRADUALLY SUBSIDE THROUGH WED AS THE SWELL ENERGY DISSIPATES. GUIDANCE IS SUGGESTING NE WINDS WILL INCREASE TO 20-25 KT ALONG THE PACIFIC COAST OF THE BAJA PENINSULA FROM 28N TO 29N ON WED.

GAP WINDS... GULF OF CALIFORNIA...NW 15-20 KT NW WINDS WILL PERSIST THROUGH TONIGHT. THE GRADIENT WILL TIGHTEN EARLY TUE WITH THE NW FLOW INCREASING TO 20-25 KT ACROSS THE NORTHERN GULF WATERS TUE MORNING...WITH 20-25 KT WINDS SPREADING S TO NEAR 25N BY EARLY WED...WITH 25-30 KT WINDS OVER THE NORTHERN HALF WITH SEAS BUILDING TO 8 FT.

GULF OF TEHUANTEPEC...MODEL GUIDANCE CONTINUES TO INDICATE WINDS RAPIDLY BECOMING NORTHERLY AT 20-30 KT WED AFTERNOON...THEN INCREASE TO STRONG GALE WED EVENING WITH A POSSIBILITY THAT WINDS MAY BRIEFLY REACH NEAR STORM STRENGTH LATE WED NIGHT INTO THU MORNING. WILL ADJUST HIGH SEAS FORECAST ACCORDINGLY BASED ON UPDATED MODEL GUIDANCE AND ANALYSIS.

GULF OF PAPAGAYO...NE 15-20 KT NOCTURNAL PULSES EXPECTED THROUGH EARLY TUE...THEN ONLY 10-15 KT DRAINAGE FLOW ON TUE NIGHT. GUIDANCE SUGGESTS BRIEF 15-20 KT CONDITIONS ON WED NIGHT...WITH A SIGNIFICANT EVENT OF 20-30 KT EVENT ON THU NIGHT.

$$ AGUIRRE

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