000
AXPZ20 KNHC 191617
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOONAL CIRCULATION NOT YET ESTABLISHED ACROSS THE REGION.
ITCZ EXTENDS FROM 06N86W AND MEANDERS WESTWARD TO 06.5N99W TO
05.5N112W TO 05N126W TO BEYOND 03.5N140W. SCATTERED MODERATE TO
STRONG CONVECTION NOTED FROM 02.5N TO 07N E OF 82W. ISOLATED TO
SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 150 NM N
AND 120 NM S OF ITCZ AXIS W OF 86W.
...DISCUSSION...
A MID TO UPPER LEVEL CYCLONE OVER THE DESERT SW OF THE U.S.
CONTINUES TO SHIFT SLOWLY EASTWARD ACROSS THE REGION...WITH AN
ASSOCIATED BROAD TROUGH AXIS EXTENDING SW TO A MIDDLE LEVEL
CYCLONE NEAR 22N128W THEN ON TO 22N135W. E OF THIS FEATURE A
RATHER FLAT UPPER RIDGE AXIS EXTENDED FROM NEAR 13N ALONG 96-97W
NORTHWARD ACROSS MEXICO AND AMPLIFIED INTO THE CENTRAL U.S.
OTHERWISE...UPPER FLOW S OF 15N REMAINS SOMEWHAT COMPLEX AS
WESTERLIES GENERALLY PREVAIL ACROSS THE REGION. ACTIVE
CONVECTION IN THE VICINITY HAS BEEN PERSISTENT IN RECENT DAYS
AND IS SUFFICIENTLY DEEP INTO THE TROPOSPHERE TO INTERRUPT AND
DIVERT THE UPPER FLOW...WITH A WEAK UPPER LEVEL ANTICYCLONE
INDUCED ACROSS ACTIVE CONVECTION OCCURRING W OF 120W.
THE DEEP LAYERED CYCLONE MOVING ACROSS THE SW U.S. WILL AID IN
PRODUCING BROAD AND ELONGATED LOW PRESSURE ACROSS MOST OF MEXICO
TODAY...WHICH IN TURN WILL YIELD MODERATE W TO SW FLOW ACROSS
THE GULF OF CALIFORNIA TODAY. OTHERWISE...A BROAD HIGH PRESSURE
RIDGE PREVAILS ACROSS THE REGION...CENTERED ON A 1025 MB HIGH
NEAR 29N143W EXTENDING SE TO NEAR 18N112W. A MODEST PRESSURE
GRADIENT BETWEEN THE RIDGE AND LOWER PRES INVOF THE ITCZ IS
YIELDING A ZONE OF NE TRADEWINDS AROUND 20 KT WITH ISOLATED
POCKETS TO 25 KT FROM 07N TO 24N W OF 137W EXTENDING TO S OF THE
HAWAIIAN ISLANDS. SEAS ACROSS THE AREA ARE RUNNING 8-10 FT IN
MIXED NE AND NW SWELL. A COLD FRONT IS APPROACHING THE REGION
JUST TO THE NW THIS MORNING AND WILL FORCE THIS SURFACE HIGH TO
THE E DURING THE NEXT FEW DAYS...AND DIMINISH SLIGHTLY THE
PRESSURE GRADIENT AND TRADE WINDS THROUGH SUN.
GALE FORCE NORTHERLY WINDS BLOWING THROUGH AND DOWNSTREAM OF THE
GULF OF TEHUATEPEC HAVE DIMINISHED TO 30 KT THIS MORNING...AS
HIGH PRES ACROSS THE GULF OF MEXICO IS SHIFTING NORTHEASTWARD.
WINDS THROUGH TEHUANTEPEC WILL DIMINISH A BIT MORE TO 20-25 KT
THIS AFTERNOON...THEN INCREASE TO 30 KT TONIGHT...AS NOCTURNAL
DRAINAGE ENHANCES THE N WINDS. NORTHERLY WINDS ARE THEN EXPECTED
TO END BY SUNDAY AFTERNOON THERE...WITH WINDS AND SEAS QUICKLY
DIMINISHING.
LOOK FOR AREAS OF ACTIVE CONVECTION TO CONTINUE TO PULSE NEAR
THE ITCZ DURING THE NEXT FEW DAYS AS AMPLE MOISTURE AND
INSTABILITY PREVAIL.
$$
STRIPLING
