[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 012328
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE 01 FEB 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 CENTERED ALONG 6N5W 2N20W 1.5N40W 6N56W 4N65W.
SCATTERED MODERATE CONVECTION S OF 5N BETWEEN 27W-44W. WIDELY
SCATTERED MODERATE OVER BRAZIL NW OF THE AMAZON DELTA AND OVER
FRENCH GUIANA AND SURINAME.

...DISCUSSION...

GULF OF MEXICO...
A MIGRATING LOW AND ASSOCIATED FRONTAL SYSTEM CONTINUES TO SLIDE
SLOWLY EWD ACROSS THE W GULF WATERS WITH AREAS OF HEAVY RAINFALL
AFFECTING PORTIONS OF THE SRN MS VALLEY AND E/CNTRL TX. BUOY OBS
INDICATE A 1012 MB LOW CENTERED NEAR 27N93W WITH A WARM FRONT
RADIATING EWD TO 29N90W 28N85W AND JUST GRAZING THE LA COAST
(OBS OVER SE LA REMAIN ELY). THE COLD FRONT EXTENDS SW OF THE
LOW TO 20N97W...ABOUT 60 NM UP THE COAST FROM VERACRUZ...AND
APPEARS TO HAVE SLOWED ITS FORWARD MOVEMENT AT THE MOMENT BUT AN
ACCELERATION SHOULD BEGIN LATER TONIGHT AS A SECOND SURGE MOVES
OFF THE TX COAST. THE FRONT IS BANKED ALONG THE SLOPES OF THE
SIERRA MADRE UP TO 24N100W BUT HAS BEGUN TO RETREAT TO THE N AS
A WARM FRONT OVER NRN MEXICO AS SEEN BY EROSION OF LOW CLOUDS
FROM ABOUT MONTERREY TO CHIHUAHUA. THE UPPER AIR PATTERN HAS
CHANGED LITTLE FROM YESTERDAY WITH A RIDGE STILL EXTENDING FROM
THE YUCATAN PENINSULA TO ALABAMA AND IS THUS CONTRIBUTING TO THE
SLOW MOVEMENT OF THE FRONT. HOWEVER...A PIECE OF ENERGY FROM THE
MID/UPPER TROF OVER THE DESERT SW WILL BREAK OFF AND MOVE INTO
THE TN/MS VALLEY...PUSHING THE FRONT THRU THE ENTIRE GULF BY FRI
MORNING. AREAS OF STEADY RAINFALL WILL CONTINUE GENERALLY N OF
THE WARM FRONT FROM LA TO N FL OVER THE NEXT 24 HRS AND THEN
WILL BECOME MORE FRONTAL IN NATURE ON THU AS THE FRONT MOVES
ACROSS THE FL PENINSULA.

CARIBBEAN...
WITH THE UPPER RIDGE LOCATED OVER THE GULF OF MEXICO...THE UPPER
FLOW OVER THE CARIBBEAN IS PRIMARILY NW/W WITH VIRTUALLY ALL
MOISTURE STREAMING N OF THE AREA INTO THE W ATLC. THE LOW LEVELS
ARE ALSO RELATIVELY DRY AND THERE ARE ONLY A FEW PATCHES OF
SHOWER ACTIVITY BEING ADVECTED WWD ALONG THE TRADES. WIDELY
SCATTERED SHOWERS ARE OCCURRING IN A BAND FROM 11.5N-14N BETWEEN
63W-71W AND ARE NEAR THE VENEZUELAN AND ABC ISLANDS. A SECOND
PATCH OF LIGHT SHOWERS EXTEND FROM THE SRN PENINSULA OF HAITI SW
TO THE HONDURAS COAST AND LOW CLOUDS ARE BANKING UP AGAINST THE
MTNS OF COSTA RICA AND W PANAMA. ELSEWHERE...THE TAIL END OF A
COLD FRONT IS APPROACHING HISPANIOLA AND PUERTO RICO FROM THE N
WITH ISOLATED SHOWERS SHOWING UP ON THE SAN JUAN RADAR.

ATLANTIC WEST OF 50W...
A 1002 MB DEVELOPING STORM CENTER IS LOCATED ABOUT 165 NM E OF
BERMUDA NEAR 33N62W WITH A COLD FRONT ENTERING THE AREA TO THE
SE ALONG 31N57W 25N57W 21N65W 21N73W. THE FRONT IS APPROACHING
THE ISLANDS OF HISPANIOLA AND PUERTO RICO WITH A BROKEN STRATOCU
FIELD PLUMMETING FROM THE W ATLC WATERS SWD TO THE E OF THE
BAHAMA ISLAND CHAIN. SCATTERED MODERATE CONVECTION IS LOCATED UP
TO 200 NM E OF THE OCCLUDED/COLD FRONT N OF 24N WITH ISOLATED
SHOWERS TRAILING TO THE SW TOWARDS THE CARIBBEAN ISLANDS. THE
UPPER FLOW IS PRIMARILY NW/WLY WITH A 110 KT JET GOING FROM THE
CAROLINAS TO 22N44W. HOWEVER...A SHARP NEGATIVELY TILTED TROF
REACHES INTO THE AREA ALONG 32N61W 27N52W AND IS THE CAUSE FOR
THE STRENGTHENING OF THE SFC LOW AND PRECIPITATION FIELD FANNING
OUT TO THE E. THE LOW IS EXPECTED TO REMAIN NEARLY STATIONARY
OVER THE NEXT 48 HRS AND DEEPEN BY ANOTHER 10 MB OR SO WITH BOTH
THE WIND FIELD AND PRECIPITATION EXPANDING IN AREA BETWEEN
45W-75W.

ATLANTIC EAST OF 50W...
A SECOND NEGATIVELY-TILTED SHORTWAVE TROF IS LOCATED FARTHER E
ALONG 32N46W 23N38W AND IS SUPPORTING THE DEVELOPMENT OF A 1010
MB LOW NEAR 25N40W. A WEAK COLD FRONT EXTENDS SW OF THE LOW TO
20N45W WHILE A WARM/STATIONARY FRONT EXTENDS TO THE NE TO
32N35W. THE UPPER DIFFLUENCE OF THE TROF IS ENHANCING SCATTERED
MODERATE CONVECTION NEAR THE LOW/FRONT PRIMARILY N OF 23N
BETWEEN 30W-43W. THE LOW WILL DEEPEN A BIT OVER THE NEXT 24 HRS
AND WILL MOVE N OUT OF THE AREA ALONG THE ERN PERIPHERY OF THE
LARGER W ATLC LOW. ELSEWHERE...DEEP-LAYERED RIDGING EXTENDS E OF
THE LOW TO ABOUT 20W WITH A BROKEN STRATOCU FIELD MOVING SW OF
MADEIRA/CANARY ISLANDS AND FEEDING INTO THE CNTRL ATLC LOW. A
CUT-OFF MID/UPPER LOW IS CENTERED OVER CNTRL MOROCCO NEAR 30N9W
BUT IS PRODUCING LITTLE SIGNIFICANT WEATHER AS DRY AIR WRAPS
300-500 NM WITHIN THE CIRCULATION. THE UPPER FLOW OVER THE
TROPICS IS COMPLETELY ZONAL WITH 70 KT EXTENDING E OF 50W
BETWEEN 12N-22N AND THERE IS NO UPPER DIVERGENCE TO SUPPORT
WIDESPREAD ITCZ CONVECTION. ANOTHER PLUME OF AFRICAN DUST AND
DRY AIR HAS ALSO MOVED OFF THE COAST AND REACHED AS FAR W AS
30W...INHIBITING CLOUD DEVELOPMENT S OF THE CAPE VERDE ISLANDS.

$$
BERG


WWWW
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