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Eastern Pacific Tropical Weather Discussion (Text)



000
AXPZ20 KNHC 011526
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC SUN FEB 01 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 
1500 UTC. 

...SPECIAL FEATURES...

...GULF OF TEHUANTEPEC GALE WARNING...                     
STRONG HIGH PRES BUILDING S INTO SOUTHERN MEXICO WILL TIGHTEN 
THE PRES GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC AND FUNNEL 
COLD AIR THROUGH THE CHIVELA PASS FROM THE SW GULF OF MEXICO 
INTO THE GULF OF TEHUANTEPEC MON NIGHT INTO TUE. N WINDS WILL 
QUICKLY REACH MINIMAL GALE FORCE ONCE THE HIGH WIND EVENT 
COMMENCES AROUND 0000 UTC. THIS GAP WIND EVENT IS FORECAST TO 
PEAK AROUND 1200 UTC ON TUE WHEN THE NORTHERLY WINDS WILL REACH 
NEAR 12N96W. SEAS WILL RAPIDLY BUILD TO 11-12 FT BY TUE MORNING. 
FRESH TO STRONG NORTHERLY WINDS ARE FORECAST TO LIKELY PERSIST 
FROM TUE AFTERNOON THROUGH WED MORNING.

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

THE MONSOON TROUGH EXTENDS FROM 09N84W TO 05N88W. THE ITCZ 
CONTINUES FROM 05N88W TO 06N100W TO 07N125W TO 06N140W. 
SCATTERED MODERATE CONVECTION IS NOTED FROM 06N TO 09N BETWEEN 
115W AND 122W. SCATTERED MODERATE ISOLATED STRONG CONVECTION CAN 
BE FOUND FROM 05N TO 07N W OF 135W.

...DISCUSSION...

ALOFT...A DEEP LAYERED TROUGH EXTENDS ACROSS NW MEXICO AND 
CENTRAL BAJA CALIFORNIA INTO THE EPAC REGION THROUGH 20N120W TO 
09N125W. STRONG SOUTHWESTERLY FLOW AHEAD OF THE TROUGH IS 
TRANSPORTING ABUNDANT MID/UPPER LEVEL MOISTURE INTO SW MEXICO. A 
SURFACE TROUGH...IN ASSOCIATION WITH THIS UPPER-LEVEL PATTERN IS 
ANALYZED OVER WESTERN MEXICO ENTERING THE EPAC WATERS NEAR 
22N105W TO 16N110W. LIGHTNING DATA SHOWS SOME CONVECTIVE 
ACTIVITY ALONG THE TROUGH AXIS S OF 18N AND NEAR 16N106W. A CUT 
OFF LOW IS FORECAST TO DEVELOP ALONG THE UPPER-LEVEL TROUGH OVER 
THE SOUTHERN GULF OF CALIFORNIA ON MON THEN THE UPPER LOW WILL 
MOVE INTO NW MEXICO BY TUE. THE PRECIPITATION ASSOCIATED WITH 
THE TROUGH WILL SHIFT SE AHEAD OF THE TROUGH AXIS WITH HEAVIEST 
RAIN EXPECTED BETWEEN MANZANILLO AND MAZATLAN ALONG THE W COAST 
OF MEXICO SUN NIGHT AND MON...INCLUDING ALSO THE MARIAS ISLANDS.

A 1024 MB SUBTROPICAL HIGH CENTERED NEAR 31N133W EXTENDS A RIDGE 
SOUTHWARD ACROSS THE N WATERS TO AROUND 17N. SCATTEROMETER DATA 
SHOWED FRESH TO STRONG NE WINDS FROM 08N TO 17N W OF 130W DUE TO 
THE PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURE IN 
THE VICINITY OF THE ITCZ. TRADE WINDS SHOULD GRADUALLY DIMINISH 
OVER W WATERS THROUGH MON AS THE HIGH PRES WEAKENS AND SHIFTS 
NORTHWARD. EXPECT INCREASING SOUTHERLY WINDS ACROSS THE NW 
CORNER OF THE AREA TUE NIGHT INTO WED AHEAD OF THE NEXT COLD 
FRONT FORECAST TO ENTER THE FORECAST REGION BY WED AFTERNOON. 
MARINE GUIDANCE SUGGESTS S-SW WINDS IN THE 25-30 KT RANGE AND 
BUILDING SEAS OF 9-14 FT AHEAD OF THE FRONT. THERE IS THE 
POSSIBILITY OF MINIMAL GALE FORCE WINDS ALONG 30N W OF 135W.

GAP WINDS...                                                    

GULF OF PAPAGAYO...THE 1110 UTC RAPIDSCAT PROVIDED OBSERVATIONS 
OF 20-25 KT NE WINDS ACROSS THE GULF OF PAPAGAYO AND DOWNWIND TO 
NEAR 90W. THE PRES GRADIENT ACROSS S CENTRAL AMERICA WILL REMAIN 
STRONG ENOUGH TO SUPPORT FRESH TO OCCASIONALLY STRONG NE WINDS 
ACROSS THIS AREA THROUGH TUE MORNING...WITH HIGHEST WINDS IN 
LATE NIGHT AND EARLY MORNING HOURS WITH THE ASSISTANCE OF THE 
NOCTURNAL DRAINAGE FLOW. 

GULF OF PANAMA...THE SAME RAPIDSCAT SHOWED MODERATE TO FRESH 
NORTHERLY ACROSS THE GULF OF PANAMA AND ALL THE WAY SOUTH TO 
NEAR 03N. AN ALTIMETER PASS INDICATED SEAS OF 4-6 FT WITH THESE 
WINDS. THESE MARINE CONDITIONS ARE EXPECTED TO PERSIST OVER THE 
NEXT COUPLE OF DAYS. 

$$ 
GR


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Page last modified: Sunday, 01-Feb-2015 15:26:28 UTC