AXNT20 KNHC 032359
TWDAT
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI JUL 03 2009
TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.
BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.
...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 41W S OF 18N MOVING W NEAR 22 KT. THIS
WAVE COINCIDES WITH A HIGH AMPLITUDE DEEP LAYER MOISTURE MAXIMUM
OBSERVED ON THE TPW PRODUCT FROM CIMSS. SATELLITE IMAGERY
INDICATES AN INVERTED-V CLOUD SIGNATURE IN THE VICINITY OF THE
WAVE AXIS S OF 12N. ISOLATED MODERATE CONVECTION REMAINS
CONFINED TO THE ITCZ FROM 5N-11N BETWEEN 40W-45W.
A TROPICAL WAVE IS ALONG 63W S OF 19N MOVING W NEAR 25 KT. THIS
WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED ON
THE TPW PRODUCT FROM CIMSS. A LARGE AREA OF SCATTERED MODERATE
CONVECTION IS OVER THE SE CARIBBEAN AND WINDWARD ISLANDS FROM
7N-16N BETWEEN 61W-68W. THIS CONVECTION IS BEING ENHANCED IN THE
SE QUADRANT OF AN UPPER LEVEL LOW IN THE ERN CARIBBEAN NEAR
14N69W.
A TROPICAL WAVE IS ALONG 81W S OF 17N MOVING W NEAR 18 KT.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION CONTINUES TO BE
ENHANCED BY UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER
LEVEL RIDGE ACROSS THE SW CARIBBEAN AND CENTRAL AMERICA. THIS
CONVECTION IS SW OF A LINE FROM 8N77W TO 15N83W.
...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 11N15W 7N27W 9N40W 8N43W 5N52W
8N62W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM
7N-13N BETWEEN 13W-20W. ISOLATED MODERATE CONVECTION IS FROM
5N-8N BETWEEN 48W-53W.
...DISCUSSION...
GULF OF MEXICO...
AS OF 2100 UTC...A STATIONARY FRONT IS OVER THE FLORIDA
PANHANDLE ALONG 30N81W 30N86W 30N89W AND INLAND ACROSS ERN
LOUISIANA. THIS FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH WITH
AXIS ALONG THE ERN U.S. SEABOARD INTO THE NE GULF NEAR 28N87W.
ISOLATED SHOWERS AND TSTMS ARE WITHIN 50 NM OF THE FRONT. A 1018
MB HIGH IS CENTERED OVER THE CENTRAL GULF NEAR 26N90W. LOW-LEVEL
INSTABILITY AND AN AREA OF UPPER DIFFLUENT FLOW ACROSS THE SE
GULF ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS FROM
24N-28N BETWEEN 83W-89W. ALSO SCATTERED SHOWERS AND TSTMS ARE
OCCURRING ACROSS THE SRN FLORIDA PENINSULA DUE TO ATMOSPHERIC
INSTABILITY AND SEABREEZE CONVERGENCE. ELSEWHERE ACROSS THE
REMAINDER OF THE GULF LIGHT WINDS ARE OBSERVED NEAR THE HIGH
PRESSURE CENTER WITH ENHANCED SELY SURFACE WINDS TO 15 KT W OF
94W.
CARIBBEAN SEA...
TWO TROPICAL WAVES ARE IMPACTING THE CARIBBEAN. THE TROPICAL
WAVE ALONG 63W IS GENERATING SCATTERED SHOWERS AND TSTMS ACROSS
THE SE CARIBBEAN AND WINDWARD ISLANDS FROM 7N-16N BETWEEN
61W-68W AND IS BEING ENHANCED IN THE SE QUADRANT OF AN UPPER
LEVEL LOW CENTERED NEAR 14N69W. THE OTHER TROPICAL WAVE ALONG
81W IN THE WRN CARIBBEAN IS GENERATING NUMEROUS SHOWERS AND
SCATTERED TSTMS SW OF A LINE FROM 8N77W TO 15N83W...BRINGING
LOCALLY HEAVY RAINFALL TO PORTIONS OF CENTRAL AMERICA.
ELSEWHERE...SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS
CUBA AND THE NEARBY COASTAL WATERS DUE TO PEAK DAYTIME HEATING
AND MAXIMUM ATMOSPHERIC INSTABILITY. THE REMAINDER OF THE
CARIBBEAN SEA IS UNDER FRESH TO STRONG ELY TRADE WIND FLOW.
ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS OVER THE ERN U.S. SEABOARD WITH AXIS
EXTENDING ACROSS NE FLORIDA INTO THE NE GULF OF MEXICO. THIS
UPPER TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION
AREA NEAR 32N79W AND CONTINUES TO SAVANNAH GEORGIA WHERE IS
TRANSITIONS TO A STATIONARY FRONT ACROSS THE FLORIDA PANHANDLE.
LOW-LEVEL CONVERGENCE AND ATMOSPHERIC INSTABILITY S OF THE FRONT
IS GENERATING SCATTERED SHOWERS AND TSTMS OVER THE ERN FLORIDA
COAST AND NEARBY W ATLC COASTAL WATERS FROM 25N-31N W OF 79W.
OTHER ISOLATED ACTIVITY ON MOIST SWLY UPPER LEVEL FLOW IS ACROSS
THE NW BAHAMAS FROM 23N-29N BETWEEN 74W-79W. FARTHER TO THE
E...AN UPPER LEVEL RIDGE ACROSS THE W/CENTRAL ATLC SUPPORTS A
1024 MB SURFACE HIGH CENTERED NEAR 27N60W WHERE GENERALLY FAIR
WEATHER IS OBSERVED N OF 20N BETWEEN 50W-74W. A 1013 MB SURFACE
LOW IS CENTERED NEAR 32N42W AND IS ASSOCIATED WITH A SHORTWAVE
TROUGH MOVING INTO THE NE ATLC. A SURFACE TROUGH EXTENDS FROM
THE LOW CENTER ALONG 31N41W 29N41W TO 25N46W. LOW-LEVEL
CONVERGENCE NEAR AND E OF THE SURFACE TROUGH IS GENERATING
SCATTERED SHOWERS FROM 25N-33N BETWEEN 34W-41W AND ALSO WITHIN
120 NM E OF THE SURFACE TROUGH. THE ERN ATLC IS BEING IMPACTED
BY A SURFACE RIDGE ANCHORED ON A QUASI-STATIONARY 1024 MB HIGH
CENTERED NEAR 32N25W THAT IS PRODUCING AN AREA OF STRONG N-NE
WINDS OF UP TO 30 KT ALONG THE W AFRICA COAST FROM 21N-33N E OF
19W.
$$
HUFFMAN
AXPZ20 KNHC 032215 CCA
TWDEP
TROPICAL WEATHER DISCUSSION...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI JUL 03 2009
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W.
BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2115 UTC.
...TROPICAL WAVES...
A TROPICAL WAVE HAS ENTERED THE FAR ERN PACIFIC PRESENTLY
ALONG 81W N OF 3N MOVING W AT 13 KT. CONVECTION ASSOCIATED
WITH THE WAVE IS MOST ACTIVE ALONG THE COAST OF CENTRAL PANAMA
WHERE SCATTERED STRONG CONVECTION IS WITHIN 30 NM OF 7.5N81.5W.
WITH THE WAVE BEING UNDER A SLIGHTLY UPPER DIFFLUENT ZONE EXPECT
CONVECTION TO BECOME MORE ACTIVE ALONG AND NEAR THE WAVE DURING
THE NIGHT.
A TROPICAL WAVE EXTENDS ALONG 110W FROM 4N TO 15N MOVING W 10-15
KT. LATEST VISIBLE SATELLITE IMAGERY SHOWS A SMALL CYCLONIC
SWIRL OF LOW CLOUDS NEAR 13N110W. CONVECTION CONTINUES TO BE
CONFINED TO WHERE THE WAVE INTERSECTS THE ITCZ.
...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N82W 9N95W 9N110W 9N120W 7N130W
5N140W. SCATTERED MODERATE CONVECTION IS OCCURRING FROM 2N-7N
BETWEEN 81W-93W...AND WITHIN 120 NM S OF THE AXIS BETWEEN
111W-120W.
...DISCUSSION...
A WELL PRONOUNCED MID/UPPER LEVEL WARM CORE ANTICYCLONE IS OVER
SW TEXAS WITH A RIDGE EXTENDING SW TO ACROSS CENTRAL BAJA
CALIFORNIA TO 23N121W TO 21N130W AND TO SW OF THE AREA AT
14N140W. A LARGE DEEP LAYER TROUGH IS WELL W OF THE REGION. A
PERSISTENT UPPER LEVEL SW FLOW PATTERN IS OBSERVED BETWEEN THESE
FEATURES. THIS CONTINUES TO ADVECT DEEP TROPICAL UPPER LEVEL
MOSITURE FROM THE CENTRAL PACIFIC NEWD INTO THE AREA FROM 21N TO
27N E TO NEAR 130W. A SWATH OF UPPER LEVEL MOISTURE JUST GRAZES
THE FAR NW CORNER OF THE AREA AHEAD OF THE TROUGH. OTHERWISE
...SATELLITE WATER VAPOR IMAGERY SHOWS THAT THE VAST MAJORITY OF
THE DISCUSSION W OF A LINE FROM 23N109W TO 16N120W TO 8N130W IS
UNDER MODERATE SUBSIDENCE PROVIDING RATHER STABLE ENVIRONMENTAL
CONDITIONS AS INDICATED BY THE PRESENCE OF PATCHES OF SCATTERED
TO BROKEN STRATOCUMULUS CLOUDS MOVING S AROUND THE ERN PERIPHERY
OF WEAK SURFACE HIGH PRESSURE PRESENT N OF 15N W OF 120W. A
LAYER OF BROKEN STRATOCUMULUS CLOUDS IS ERODING OVER THE FAR NE
PART OF THE AREA N OF 19N E OF 119W TO ALONG THE COAST OF BAJA
CALIFORNIA.
OVER THE REMAINDER OF THE AREA ABUNDANT UPPER LEVEL MOISTURE
IS OBSERVED ON SATELLITE IMAGERY...PRIMARILY ATTRIBUTED TO
MODERATE TO STRONG ELY SHEAR OCCURRING ON THE SRN PERIPHERY THE
ANTICYCLONE OVER SW TEXAS...BUT IS ALSO BEING ENHANCED IN THE
ITCZ REGION AND SURROUNDING AREAS WHICH REMAIN UNDER A BROAD
LOW PRES FIELD. AN UPPER LEVEL CYCLONIC CIRCULATION OVER
THE SW CARIBBEAN SEA IS CONTRIBUTING FURTHER TO THIS MOISTURE BY
ADVECTING ADDITIONAL MOISTURE FROM ONGOING CONVECTION OVER THE
FAR SW CARIBBEAN SEA...AND OVER CENTRAL AMERICA S OF HONDURAS
SWD INTO THE FAR ERN PACIFIC.
BOUNDARY LAYER WINDS CONTINUE TO BE ON THE LIGHT SIDE ACROSS THE
SUBTROPICS DUE TO A STALLED FRONT NW OF THE AREA INTERRUPTING
THE SUBTROPICAL RIDGING. NW 20 KT WINDS ARE FORECAST TO INCREASE
OVER THE FAR NE CORNER OF THE AREA LATE SUN INTO MON AS THE
SUB-TROPICAL HIGH TAKES MORE HOLD OF THE AREA...BEING THE MORE
TYPICAL SCENARIO.
THE PRES GRADIENT BETWEEN WEAK SURFACE HIGH PRES OVER SRN MEXICO
AND BROAD LOW PRES ALONG AND NEAR THE ITCZ WILL INCREASE LOW TO
MID-LEVEL E-SE WINDS SW OF MEXICO DURING THE NEXT FEW DAYS. AT
THE SAME TIME...CROSS EQUATORIAL SLY FLOW WILL INTERACT WITH THE
INCREASING E TO SE FLOW RESULTING IN AN AREA OF INCREASED
LOW-LEVEL CYCLONIC VORTICITY WELL OFF THE MEXICAN COAST BEGINNING
WITHIN THE NEXT 36-48 HOURS. THIS IS EXPECTED TO LEAD TO GENESIS
OF SURFACE LOW PRES IN THE VICINITY 13N105W...AND TO NEAR 15N109W
BY 48 HOURS. A SURFACE TROUGH IS CURRENTLY ANALYZED ALONG 102W
FROM 5N-15N MOVING W 13 KT. THIS IS MOST PROBABLE THE FEATURE
THAT LENDS TO GENESIS OF THE FORECAST LOW. A PARTIAL QUIKSCAT
PASS FROM THIS MORNING AGAIN SHOWED BROAD CYCLONIC TURNING IN
THE BOUNDARY LAYER CUMULUS FIELD...AND ALONG WITH SATELLITE
IMAGERY DEPICTS THE TROUGH AS PART OF THE BROAD AREA OF
DISORGANIZED DISTURBED WEATHER THAT MAY EVENTUALLY CONSOLIDATE
TO FORM THE FORECAST LOW. WINDS OF 20-25 KT ARE FORECAST IN THE
NE QUADRANT OF THE LOW WITHIN A DISTANCE OF ABOUT 180 NM TO 300
NM DUE TO THE RESULTANT PRES GRADIENT BETWEEN THE LOW AND THE
GEOGRAPHIC INFLUENCE OF THE MEXICAN COAST. LATEST WAVEWATCH
GUIDANCE SHOWS SEAS BUILDING TO 8-10 FT IN THE NE QUADRANT OF
THE LOW BY 48 HOURS.
CROSS EQUATORIAL FLOW IS BRINGING SE TO S WINDS TO 20 KT FROM 2N
TO 8N BETWEEN 105W AND 125W...AND S OF 6N W OF 134W. ALSO...
MODERATE EASTERLY LOW/MID-LEVEL FLOW OVER THE W CARIBBEAN WILL
BLEED INTO THE GULF OF PAPAGAYO...WITH SURFACE WINDS BEING
ACCELERATED INTO THE 20-25 KT RANGE NEAR AND DOWNSTREAM OF THE
GULF OF PAPAGAYO OVERNIGHT INTO EARLY SAT DUE TO VARIATIONS
IN LOCAL TOPOGRAPHY. THESE WINDS WILL BE MAXIMIZED LATE AT NIGHT
WHEN NOCTURNAL DRAINAGE FLOW IS AT ITS PEAK. STRONG SOUTHERN
HEMISPHERIC STORMS ARE ALSO SENDING LONG-PERIOD SWLY SWELLS NWD
WITH PERIODS OF 15-17 SECONDS WITH SEAS IN THE 8-10 FT RANGE
FROM 2N TO 8N BETWEEN 105 AND 125W. THESE SEAS ARE EXPECTED TO
BE WITHIN THE AREA S OF 5N BETWEEN 94W-118W IN 48 HRS...AND
MAY IMPACT THE SW COAST OF MEXICO BEGINNING ON SUN AS LARGE
BATTERING WAVES.
$$
AGUIRRE
