Hurricane Advisories Hurricane advisories

000
AXPZ20 KNHC 260951
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JAN 26 2012

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.

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

THE MONSOON TROUGH EXTENDS FROM 07N77W TO 08N84W TO 05N88W WHERE
LOW LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ WHICH CONTINUES
W TO 08N109W TO BEYOND 04N140W. SCATTERED MODERATE CONVECTION IS
NOTED FROM 04N TO 13N BETWEEN 100W AND 108W. SCATTERED MODERATE
TO STRONG CONVECTION IS OBSERVED WITHIN 90 NM EITHER SIDE OF A
LINE FROM 07N122W TO 06N131W.

...DISCUSSION...

A DEEP LAYERED CYCLONE OVER CENTRAL TEXAS HAS AN UPPER TROUGH
EXTENDING S ACROSS CENTRAL OLD MEXICO TO THE PACIFIC AT 19N105W
TO 11N113W. THE NARROW PLUME OF UPPER MOISTURE ORIGINATING IN
THE TROPICAL PACIFIC THAT HAS BEEN STREAMING NE INTO THE
CONVECTION AHEAD OF THIS CYCLONE HAS ALMOST COMPLETELY
EVAPORATED ANS IT MOVES NE ACROSS CENTRAL OLD MEXICO AND THE W
GULF OF MEXICO. IN THE MEANTIME AN UPPER CYCLONE HAS CUT OFF
FROM THE TROUGH AT 19N137W WITH A TROUGH EXTENDING THROUGH
ANOTHER UPPER CYCLONE AT 12N138W...TO TROUGH BASE AT 06N137W. AN
UPPER ANTICYCLONE IS CENTERED NEAR 19N126W WITH ITS ENVELOPE OF
ANTICYCLONIC FLOW COVERING THE UPPER LEVELS N OF 22N W OF 110W.
UPPER MOISTURE ORIGINATING OVER THE PACIFIC N OF THE HAWAIIAN
ISLANDS IS SPREADING E ALONG THE N PERIPHERY OF THIS
ANTICYCLONE...ROUGHLY ALONG 35N...AND SPILLING SE ACROSS SE
CALIFORNIA AND MOST OF NEW MEXICO AND ARIZONA...AND WILL MOVE
ACROSS EXTREME NORTHERN OLD MEXICO LATER TODAY. OTHERWISE THE
UPPER LEVELS APPEAR VERY DRY N OF 17N W OF 95W...AND FROM O6N TO
17N W OF 137W.

AN UPPER ANTICYLONE IS CENTERED JUST S OF THE AREA NEAR 03S127W
WITH A RIDGE EXTENDING N ACROSS THE EQUATOR TO A GENTLE CREST
ALONG POINTS 10N137W TO 17N126W TO 08N110W TO BEYOND 00N104W. AN
AREA OF UPPER DIFFLUENCE IS INDUCED JUST TO THE E OF THE UPPER
TROUGH OVER THE DEEPS TROPICS NEAR 06N137W WITH THE DIFFLUENCE
SPREADING E UNDER THE WESTERN PORTION OF THIS TROPICAL RIDGE.
THIS IS ENHANCING THE DEEP CONVECTION. UPPER LEVEL GUIDANCE
SUGGESTS THIS AREA OF UPPER DIFFLUENCE AND THUS ENHANCED
CONVECTION MAY CONTINUE...BUT SHIFT SLIGHTLY TO THE NE TONIGHT
AND FRI.

AN UPPER RIDGE EXTENDS FROM SE TO NW ACROSS THE W CARIBBEAN TO A
CREST OVER THE NE GULF OF MEXICO AT 28N85W. THIS RESULTS IN
SOUTHWESTERLY UPPER FLOW OVER THE TROPICAL PACIFIC TO THE E OF
100W...WITH AN AREA OF UPPER DIFFLUENCE NEAR 06N103W ENHANCING
THE AREA OF SCATTERED MODERATE CONVECTION PREVIOUSLY DESCRIBED.
THE RESULTANT DEBRIS MOISTURE IS ADVECTED NE...BUT SEEMS TO
EVAPORATE BEFORE REACHING CENTRAL AMERICA.

AT THE LOW LEVELS A SURFACE HIGH IS QUASI-STATIONARY NEAR
34N130W WITH A BROAD RIDGE ACROSS THE AREA N OF THE ITCZ AND W
OF 105W. NE TRADES AT 20 KT ARE OBSERVED S OF THE ASSOCIATED
RIDGE TO ALONG 06N TO THE W OF 123W...WITH SEAS 8 TO 12 FT IN
LONG PERIOD NW SWELL MIXING WITH THE NE TRADE SWELL. MIXED N
SWELL IS MAINTAINING COMBINED SEAS OF 7 TO 10 FT ELSEWHERE W OF
LINE FROM THE SW BAJA CALIFORNIA PENINSULA TO 08N120W TO
03N140W. BY TONIGHT...THE GRADIENT WILL SHIFT THE AREA OF
ENHANCED NE TO E WINDS AT 20 TO 25 KT TO ACROSS THE PACIFIC
WATERS FROM 23W TO 32N TO THE W OF 124W...WITH COMBINED SEAS OF
10 TO 14 FT IN MIXED NE AND NW SWELL. FURTHER S...ROUGHLY FROM
07N TO 15N TO THE W OF 130W...NE WINDS WILL CONTINUE AT 20 KT
WITH SEAS 9 TO 11 FT IN THE MIXED NE AND NW SWELL. LONG PERIOD
NE AND NW SWELL WILL MAINTAIN COMBINED SEAS OF 7 TO 10 FT ACROSS
THE REMAINDER OF THE DISCUSSION AREA TO THE N OF 10N W OF 115W
AND FROM 04N TO 10N W OF 120W.

GULF OF CALIFORNIA...NW TO N WINDS HAVE DIMINISHED TO 15 TO 20
KT OVER THE GULF OF WATERS TO THE N OF 24N...AND SHOULD FURTHER
DIMINISH TO 10 TO 15 KT LATER TODAY. NORTHERLY WINDS WILL
INCREASE AGAIN TO 15 TO 20 KT OVER THE NORTHERN GULF OF
CALIFORNIA WATERS ON SAT MORNING.

GULF OF PAPAGAYO...NE WINDS WILL CONTINUE TO PULSE AT 15 TO 20
KT FOR THE NEXT 48 HOURS THEN INCREASE TO 20 KT BY MIDDAY SAT.

GULF OF TEHUANTEPEC...A COLD FRONT WILL MOVE THROUGH THE SW GULF
OF MEXICO TODAY FOLLOWED BY STRONG NORTHERLY WINDS. THESE WINDS
WILL SURGE THROUGH THE ISTHMUS OF TEHUANTEPEC AT 20 KT AROUND
SUNSET TODAY AND SHOULD STRENGTHEN TO MINIMAL GALE FORCE LATE
TONIGHT...WITH THE GALE CONDITIONS LASTING THROUGH FRI
AFTERNOON. NOTE THAT MODEL GUIDANCE HAS BACKED OFF CONSIDERABLY
ON THE STRENGTH AND THE DURATION OF THIS EVENT...AND THUS OUR
TEXT AND GRAPHICAL PRODUCTS HAVE BEEN ADJUSTED. THIS LATEST
GUIDANCE STILL SUGGESTS THE NORTHERLY WINDS WILL DIMINISH TO 20
TO 25 KT BY EARLY SAT...BUT INCREASE AGAIN TO A GALE LATE SAT
NIGHT...AND CONTINUING THROUGH SUNRISE MON.

$$
NELSON