Tropical Weather Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.