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000
AXPZ20 KNHC 190230
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT APR 19 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0215 UTC.


...SPECIAL FEATURE...

GALE WARNING FOR THE GULF OF TEHUANTEPEC...

A SURFACE LOW OVER THE NE GULF OF MEXICO HAS DRAGGED A COLD FRONT THROUGH THE S-CENTRAL GULF OF MEXICO. NORTHERLY FLOW HAS INCREASED ACROSS THE WESTERN GULF OF MEXICO IN THE WAKE OF THIS FRONT WITH NORTHERLY 20-25 KT WINDS CURRENTLY SURGING INTO THE GULF OF TEHUANTEPEC. THE GRADIENT WILL FURTHER TIGHTEN TONIGHT WITH MINIMAL GALE CONDITIONS EXPECTED FROM MIDNIGHT THROUGH SUNRISE ON SAT. WINDS WILL QUICKLY DIMINISH THROUGHOUT THE DAY ON SAT WITH ONLY N-NE 20-25 KT WINDS EXPECTED ON SAT EVENING THROUGH SUNRISE ON SUN. THE NOCTURNAL MAXIMUM DRAINAGE SHOULD ONLY MAX 15-20 KT EACH NIGHT FROM SUN NIGHT THROUGH WED NIGHT.


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

THE EPAC MONSOON TROUGH EXTENDS SW FROM THE COAST OF PANAMA AT 08N82W TO 07N91W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ AXIS...WHICH CONTINUES SW TO 04N110W...THEN NW TO 06N122W....THEN W TO BEYOND 06N140W.

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ALONG THE MONSOON TROUGH AND ITCZ AXIS WITHIN 150 NM EITHER SIDE OF LINES FROM 07N80W TO 04N104W AND FROM 08N118W TO 04N138W.

A PERSISTENT MID-UPPER TROUGH HAS A SURFACE REFLECTION EXTENDING FROM 14N109W TO 03N111W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FLARING WITHIN 75 NM OF 13.5N108.5W. ISOLATED MODERATE TO STRONG CONVECTION IS OBSERVED WITH 60 NM EITHER SIDE OF A LINE FROM 09N108W TO 03N110W.


...DISCUSSION...

AN UPPER CYCLONE IS OVER EXTREME SOUTHERN CALIFORNIA WITH A MID TO UPPER TROUGH EXTENDING SW TO A BASE NEAR 17N131W. DENSE UPPER DEBRIS IS CONCENTRATED E OF THE TROUGH AXIS AND SPREADING NE ACROSS NORTHERN MEXICO...WITH SOME OF THE MOISTURE ALSO SPREADING N ACROSS SOUTHERN CALIFORNIA...ARIZONA...NEW MEXICO AND W TEXAS. SOME OF THIS MOISTURE IS JUST NOW SPREADING E ACROSS THE WESTERN GULF OF MEXICO.

AN UPPER LEVEL ANTICYCLONE IS QUASI-STATIONARY JUST W OF THE AREA AT 08N141W WITH A RIDGE EXTENDING E ACROSS THE TROPICS TO A CREST NEAR 05N114W. UPPER DIFFLUENCE UNDER THIS RIDGE CONTINUES TO ENHANCE CONVECTION ALONG THE ITCZ TO THE W OF 115W.

THE PREVIOUSLY DESCRIBED SURFACE TROUGH FROM 14N109W TO 03N111W IS UNDER AN UPPER TROUGH THAT IS QUASI-STATIONARY FROM 03-15N BETWEEN 103-113W. THIS UPPER TROUGH SEPARATES THE ANTICYCLONIC FLOW JUST DESCRIBED OVER THE SW PORTION FROM ANOTHER TROPICAL ANTICYCLONE OVER THE SE PORTION ASSOCIATED WITH AN UPPER RIDGE EXTENDING W OFF THE COAST OF COLOMBIA ALONG 07N TO THE E OF 100W. THIS UPPER RIDGE IS IN PHASE WITH THE LOWER LEVER MONSOON TROUGH AND ITCZ...AND IS SUPPORTING THE PREVIOUSLY DESCRIBED CONVECTION. SOME OF THE RESULTANT DEBRIS MOISTURE IS ADVECTED NE ACROSS CENTRAL AMERICA...THEN THINS AS IT TURNS E-NE ACROSS THE CENTRAL CARIBBEAN.

A SURFACE HIGH PRESSURE RIDGE EXTENDS FROM 29N140W TO NEAR 18N105W. NE TRADES ARE ENHANCED TO 15-20 KT BETWEEN THE RIDGE AND 07N TO THE W OF 120W...WITH SEAS OF 6-8 FT IN MIXED LONG PERIOD NW AND NE SWELL WITH ADDITIONAL LONG PERIOD CROSS- EQUATORIAL SE SWELL. THIS AFFECTED AREA S OF THE RIDGE WILL PERSIST THROUGH THE WEEKEND. NW TO N 15 KT WINDS WILL CONTINUE THROUGH THE WEEKEND TO THE NE OF THE RIDGE TO THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA WITH SEAS OF 4-5 FT. A NEW BATCH OF NW SWELL WILL ARRIVE AT 30N140W SAT NIGHT...AND CONTINUE TO PROPAGATE E REACHING THE NW COAST OF THE BAJA PENINSULA IN THE FORM COMBINED SEAS OF 6-9 FT ON MON. SEAS OF 8-9 FT IS EXPECTED ACROSS THE DISCUSSION WATERS N OF 20N BETWEEN 112W-135W ON TUE.

$$ NELSON

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