[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 292347
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT 29 JAN 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN
COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...

ITCZ AXIS IS ALONG 4N8W 1N20W EQ37W 1S46W.  ISOLATED MODERATE
WITHIN 45 NM OF AXIS BETWEEN 17W-31W.

...DISCUSSION...

GULF OF MEXICO...
GENERAL WNW FLOW ALOFT COVERS MUCH OF THE REGION WITH A MID/
UPPER LOW OVER THE OHIO VALLEY EXTENDING A TROUGH S THRU THE
FLORIDA PANHANDLE.  THIS TROUGH CONTINUES TO SUPPORT A 1016 MB
LOW S OF PENSACOLA FLORIDA NEAR 29.5N87W.  A WARM FRONT LIES E
OF THE LOW JUST N OF CEDAR KEY ACROSS THE PENINSULA TO JUST E OF
JACKSONVILLE WHILE A COLD FRONT EXTENDS FROM THE LOW TO 27N90W
BECOMING STATIONARY TO 26N93W INTO S TEXAS A LITTLE N OF
BROWNSVILLE THEN BANKED ALONG THE E SLOPES OF THE SIERRA
MADRES.  THE FRONT IS FAIRLY WEAK ESPECIALLY OVER MEXICO BUT
THERE IS ENOUGH ELY FLOW AND LOW-LEVEL MOISTURE TO PRODUCE
OVERCAST CLOUDINESS AND SOME SHOWERS IN THE UPSLOPE CONDITIONS.
E OF THE GULF LOW... WIDELY SCATTERED SHOWERS ARE N OF 28.5N
BETWEEN JACKSONVILLE AND 86W WITH A FEW EMBEDDED TSTMS
POSSIBLE.  THIS LOW WILL TRACK NE THRU FLORIDA OVERNIGHT
BRINGING THE BULK OF THE PRECIPITATION WITH IT BUT SHOULD SLOWLY
DRY OUT NORTHERN FLORIDA AND THE REST OF THE SUNSHINE STATE BY
EARLY MON.  THE STATIONARY FRONT IN THE W GULF IS FORECAST TO
MOVE LITTLE WITH THE ZONAL FLOW ALOFT HOLDING IT IN PLACE AND
THE WARM GULF WATERS COMBINED WITH THE RELATIVELY COOL
CONTINENTAL AIRMASS KEEPING A TEMPERATURE GRADIENT INTACT FOR
THE NEXT COUPLE OF DAYS UNTIL A STRONGER SYSTEM EXITS THE SW USA
FOR NEXT WEEK.  S OF THE FRONTAL SYSTEM... GENERALLY PARTLY
CLOUDY SKIES ARE THE RULE WITH INCREASING DRIER AIR FROM N TO S
OVER THE GULF.  ANOTHER GULF LOW MAY FORM FOR EARLY NEXT WEEK ON
THE STATIONARY BOUNDARY IN THE WESTERN GULF WITH A ROUND OF
SHOWERS/POSSIBLE TSTMS FOR THE W GULF COAST BEGINNING LATE SUN.

CARIBBEAN SEA...
BENIGN WEATHER PATTERN IS IN PLACE WITH CLUSTERS OF TRADEWIND
SHOWERS THE MAIN STORY.  ISOLATED SHOWERS ARE S OF 18.5N W OF
85W NEAR THE GULF OF HONDURAS AND BETWEEN 66W-75W GENERALLY NEAR
AND N OF THE ABC ISLANDS.  AN INCREASE IN MOISTURE IS ON THE WAY
FOR THE E CARIBBEAN INCLUDING HISPANIOLA THRU PUERTO RICO AND
THE LEEWARD ISLANDS FOR TOMORROW AS A WEAKENING COLD FRONT
CROSSING 20N SHOULD UP THE SHOWER CHANCES FOR THE REGION.  THIS
FRONT IS FORECAST TO BRING ANOTHER SHOT OF DRY LOW-LEVEL AIR FOR
THE NE CARIBBEAN WITH DEWPOINTS PRIMARILY IN THE 60S.  THE
MIDDLE TO UPPER LEVELS OF THE ATMOSPHERE ARE QUITE DRY...
COURTESY OF CONVERGENCE/SUBSIDENCE FROM COMBINATION OF THE BROAD
W/CENTRAL ATLC TROUGH AND RIDGING OVER S AMERICA.

ATLANTIC OCEAN...
STRONG COLD FRONT HAS SWEPT OUT MOST OF THE W AND CENTRAL ATLC
AND LIES FROM 31N49W TO 24N54W TO JUST N OF HISPANIOLA NEAR
20N70W DISSIPATING OVER CUBA.  BROKEN LOW CLOUDS AND ISOLATED
SHOWERS ARE BEHIND THE FRONT WITH A SURFACE TROUGH AHEAD OF THE
FRONT BY ABOUT 240 NM N OF 22N SERVING AS A MECHANISM FOR WIDELY
SCATTERED SHOWERS N OF 23N BETWEEN 38W-45W.  THE COLD FRONT IS
BEING SUPPORTED BY A BROAD MID/UPPER TROUGH THAT DOMINATES THE W
AND CENTRAL ATLC BETWEEN 45W-FLORIDA WITH A ROUGH AXIS ALONG
57W.  THE UPPER PATTERN HAS A SHORTER WAVELENGTH IN THE E ATLC
WITH A RIDGE AXIS ALONG 40W N OF 20N WITH A SLIGHTLY DEEPER
TROUGH FROM THE W CAPE VERDES TO 31N19W.  HIGH CLOUDS ABOUND
NEAR THE RIDGE AXIS AND E OF THE TROUGH AXIS N OF 20N.  A FEW
SHOWERS ARE WITHIN 120 NM OF 27N29W IN THE COOLER AIR NEAR THE
TROUGH AXIS.  DEEPER INTO THE TROPICS... A STRONG MID/UPPER HIGH
NEAR 3S33W RIDGES NW TO 4N52W THEN WNW TO 8N70W AND CONTROLS THE
ENTIRE REGION W OF 30W.  BROKEN HIGH CLOUDS ARE S OF 15N W OF
30W.  STRONG MID/UPPER DRY AIR IS PRESENT BETWEEN 10N-20N W OF
THE CAPE VERDES WITH FEW LOW CLOUD-BASED SHOWERS.

$$
BLAKE


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