Tropical Weather Discussion
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000
AXPZ20 KNHC 261003
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON JAN 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0945 UTC.

...SPECIAL FEATURES...
A GALE WARNING REMAINS IN EFFECT FOR THE GULF OF TEHUANTEPEC
WHERE WINDS ARE PRESENTLY N-NE AT 30-35 KT WITH SEAS IN THE 9-13
FT RANGE. THESE CONDITIONS EXTEND SOUTHWARD TO 14.5N BETWEEN 94W
AND 96W. THESE WINDS ARE FORECAST TO QUICKLY INCREASE TO 35-40
KT AROUND DAYBREAK THIS MORNING AS ANOTHER SHOT OF STRONG HIGH
PRES SURGES SEWD ACROSS EASTERN AND SE MEXICO BRINGING MORE COLD
DENSE AIR ACROSS THE GULF. SEAS ARE FORECAST TO BUILD TO 11-17
FT IN THE GULF AS THESE WIND CONDITIONS INCREASE. SEAS WILL BE
FURTHER TO AROUND 19 FT BY LATE TONIGHT...AND ONLY SUBSIDE
SLIGHTLY TUE AND WED AS LITTLE LET UP IS EXPECTED WITH THE GALE
WINDS. THIS GALE WIND EVENT IS FORECAST TO BE OF LONG
DURATION...LASTING THROUGH MUCH OF THE WEEK.

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

MONSOON TROUGH EXTENDS FROM 10N85W TO 05N90W TO 04N98W WHERE
SCATTEROMETER WINDS INDICATE THE ITCZ BEGINS...AND EXTENDS TO
07N110W TO 08N121W TO 07N130W TO 06N140W. NO SIGNIFICANT
CONVECTION IS NOTED.

...DISCUSSION...
ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE FORECAST AREA
W OF 100W. A STRONG CUT-OFF LOW IS CLEARLY EVIDENT ON WATER
VAPOR IMAGERY TO NEAR 28N122W WITH A TROUGH EXTENDING FROM THE
LOW TO SE TO SRN BAJA CALIFORNIA AND TO NEAR 10N105W. ABUNDANT
MIDDLE TO UPPER LEVEL MOISTURE IS STREAMING NE AHEAD OF THE
TROUGH AXIS FURTHER ENHANCED BY A VERY ACTIVE SUBTROPICAL JET
STREAM BRANCH THAT EXTENDS FROM 17N117W NEWD TO ACROSS BAJA
CALIFORNIA...NW MEXICO...MOST OF SRN CALIFORNIA AND THE SW
CONUS. A QUITE IMPRESSIVE DIFFLUENT PATTERN ALOFT IS TO THE SE
OF THE LOW AND JET STREAM BRANCH...AND IS HELPING TO TRIGGER OFF
SCATTERED SHOWERS AND ISOLATED TSTMS TO THE SE OF THE TROUGH TO
NEAR 104W. A SHIELD OF PRECIPITATION CONSISTING OF SCATTERED
SHOWERS IS N OF 24N TO THE E AND SE OF THE LOW AND TROUGH
REACHING EASTWARD TO JUST W OF THE BAJA CALIFORNIA PENINSULA. TO
THE W OF THE UPPER LOW AND TROUGH...A NARROW RIDGE IS ALONG 131W
N OF 21N...AND IS SLIDING EASTWARD. A RATHER NARROW LONGWAVE WAVE
TROUGH HAS ENTERED THE FAR WESTERN PORTION OF THE AREA ALONG
139W AND N 13N. OVER THE FAR EASTERN PORTION OF THE AREA...BROAD
MID/UPPER LEVEL RIDGING IS PRESENT E OF ABOUT 100W WITH A RIDGE
AXIS STRETCHING FROM THE TEXAS PANHANDLE SEWD TO SE MEXICO...AND
TO ACROSS CENTRAL AMERICA.

AT THE SURFACE...THE STRONG HIGH PRES THAT WAS LOCATED WELL N OF
THE AREA DURING THE PREVIOUS DAYS CONTINUES TO WEAKEN AS A COLD
FRONT ENTERS THE FAR NW CORNER OF THE AREA. THIS STATIONARY HIGH
PRES OF 1019 MB LOCATED NEAR 34N127W EXTENDS A RIDGE SW TO COVER
MOST OF THE DISCUSSION AREA N OF 20N. WINDS HAVE DIMINISHED
ALONG THE THE SOUTHERN PERIPHERY OF THE RIDGE WITH RECENT
SCATTEROMETER DATA SHOWING MAINLY GENTLE TO MODERATE NE WINDS
FROM 15N TO 21N W OF 120W. A WEAK TROUGH...REFLECTION OF THE
ABOVE MENTIONED UPPER LEVEL LOW..IS ANALYZED FROM 24N115W TO
20N114W TO 16N115W. AN AREA OF FRESH TO STRONG E TO SE WINDS WAS
CAPTURED MULTIPLE ASCAT PASSES FROM LATE LAST NIGHT WITHIN 120
NM E OF THE TROUGH FROM 21N TO 24N. SEAS THERE ARE IN THE 8-10
FT RANGE. THIS TROUGH IS FORECAST TO WEAKEN THROUGH
TONIGHT...AND DISSIPATE TUE NIGHT INTO WED WITH THE CULPRIT PRES
GRADIENT OF THE FRESH TO STRONG WINDS RELAXING.

AN AREA OF LARGE LONG PERIOD NW SWELLS...ASSOCIATED WITH THE
AFOREMENTIONED COLD FRONT IS PROPAGATING SEWD TO THE W OF A LINE
FROM ABOUT 32N125W TO 17N130W TO 09N140W. THESE SWELLS ARE
RESULTING IN MAX COMBINED SEAS OF UP TO 11 FT WITH PERIODS OF 16-
17 SECONDS. THE COLD FRONT WILL REACH A POSITION FROM 30N136W TO
WEAK LOW PRES 25N138W AND TO 21N140W BY LATE TONIGHT...AND
GRADUALLY TRANSITION TO A DISSIPATING STATIONARY FRONT BY LATE
TUE NIGHT. A TIGHT GRADIENT WILL BRIEFLY DEVELOP W OF THE FRONT
AND LOW TONIGHT ALLOWING FOR FRESH TO STRONG N-NE WINDS THERE
WITH SEAS IN THE 9-10 FT. THESE WINDS AND SEAS DIMINISH TUE
NIGHT AS THE FRONTAL BOUNDARY DISSIPATES.

GAP WINDS...
FRESH TO STRONG NE-E WINDS THROUGH THE GULF OF PAPAGAYO WILL
CONTINUE THROUGH WED AS STRONG HIGH PRES BUILDS ACROSS THE
WESTERN CARIBBEAN. THESE WINDS SHOULD INCREASE TO AROUND 30 KT
EARLY ON WED.

FRESH TO STRONG N WINDS SEEPING THROUGH THE GULF OF PANAMA REACH
S TO NEAR 05N AND BETWEEN 79W-81W. THESE WINDS WILL CHANGE
LITTLE THROUGH WED WITH THERE TO 8 OR 9 FT.

$$
AGUIRRE


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