[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 260003
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU JAN 25 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...
CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...
NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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
2345 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 3N20W 2N40W CROSSING THE
EQUATOR AT 45W. ISOLATED MODERATE CONVECTION IS WITHIN 120 NM
EITHER SIDE OF THE AXIS BETWEEN 25W-33W.

...DISCUSSION...
GULF OF MEXICO...
A COLD FRONT CONTINUES TO PRESS S AND E ACROSS THE SRN GULF.
AT 21Z...THE FRONT EXTENDS WSW THROUGH THE STRAITS OF FLORIDA TO
JUST NW OF THE YUCATAN PENINSULA NEAR 22N92W...AND THEN
CONTINUES S AS A STATIONARY FRONT THROUGH THE ERN BAY OF
CAMPECHE. TEMPERATURES ACROSS S FLORIDA HAVE CONTINUED TO DROP
OVER THE LAST FEW HOURS WITH THE FRONTAL PASSAGE...WITH READINGS
CURRENTLY IN THE MID 50S TO LOW 60S BEHIND THE FRONT...AND IN
THE 70S TO 80S AHEAD OF THE FRONT. DOPPLER RADAR SHOWS A SWATH
OF SHOWERS AND TSTMS WITH THE FRONT MOVING THROUGH THE STRAITS
OF FLORIDA AND THROUGH THE WRN BAHAMAS. THICK CLOUDINESS AND
ISOLATED SHOWERS EXIST BEHIND THE FRONT WITHIN 180 NM...WITH
CLEARING BEHIND THAT ACROSS THE NRN GULF WATERS N OF 26N.
STRONG NLY WINDS CONTINUE TO BLOW IN THE SW GULF WHERE A GALE
WARNING IS IN EFFECT BUT SET TO EXPIRE AT 26/0000 UTC...REFER TO
THE HIGH SEAS FORECAST UNDER HEADER MIAHSFAT2 FOR DETAILS. HIGH
PRESSURE WILL TAKE OVER THE GULF SFC PATTERN TEMPORARILY INTO
FRI...BEFORE ANOTHER LOW WITH INCREASING WINDS/SEAS DEVELOPS IN
THE NW GULF DURING SAT.

CARIBBEAN SEA...
MOST OF THE CARIBBEAN IS IN A VERY STABLE REGIME AS A MID TO
UPPER LEVEL RIDGE REMAINS ANCHORED ACROSS THE REGION. ABUNDANT
DRY AIR/SUBSIDENCE IS SUPPRESSING CONVECTIVE ACTIVITY. A SLIGHT
CHANGE IN THE PATTERN IS BEGINNING TO AFFECT THE NW CARIB AS A
PREFRONTAL TROUGH AND COLD FRONT MOVE ACROSS THE AREA. AS OF
21Z...THE PREFRONTAL TROF WAS ANALYZED IN THE GULF OF HONDURAS
NEAR 16N87W TO WRN CUBA. LIKE MOST FRONTS IN THE CARIB...THIS
ONE IS EXPECTED TO WEAKEN BUT IT WILL BE DEFINED ENOUGH TO TURN
THE FLOW NLY ADVECTING IN SOME COOLER WEATHER FOR THE NW CORNER
OVER THE NEXT DAY OR TWO. ELSEWHERE EASTERLY TRADES ARE MAINLY
IN THE 15-25 KT RANGE...STRONGEST N OF THE COLOMBIAN
COAST...WHICH IS TYPICAL DUE TO THE LOWER PRES OVER COLOMBIA.
SCATTERED PATCHES OF LOW LEVEL MOISTURE ARE DRIVEN W BY THE
TRADES IN THE ERN CARIB AND THEN STEERED TO THE N-NE AHEAD OF
THE PREFRONTAL TROF ACROSS JAMAICA...THE CAYMAN ISLANDS AND
CUBA.

ATLANTIC OCEAN...
A STRONG FRONTAL SYSTEM CONTINUES TO EVOLVE THROUGH THE WRN
ATLC. A 1006 MB LOW IS LOCATED NEAR 30N71W WITH A COLD FRONT
EXTENDING SW THROUGH THE BAHAMAS AND INTO THE STRAITS OF FLORIDA
AS OF 21Z.  DENSE CLOUDINESS AND STRATIFORM PRECIP IS WIDESPREAD
NW OF THE BOUNDARY. MORE CONVECTIVE WEATHER IS ALONG THE FRONT
WITHIN 60NM. GFS SHOWS THE LOW NEAR 31N70W MOVING TO THE NE AND
BECOMING ABSORBED BY A LARGER LOW TO THE NW...CREATING A VERY
LARGE AND STRONG STORM SYSTEM IN THE NW ATLC TOMORROW. THIS WILL
SPREAD A STRONG NW SWELL THROUGH EXPOSED CARIBBEAN BEACHES
THROUGH THE WEEKEND AND EARLY NEXT WEEK. ALOFT...THE STRONG
RIDGE CENTERED IN THE CARIB COVERS MOST OF THE AREA W OF 50W. A
SUBTROPICAL JET...WITH CORE WINDS NEAR 150 KT...IS RIDING ALONG
THE N PERIPHERY OF THE RIDGE SPREADING A LARGE SWATH OF MOISTURE
ACROSS THE AREA N OF 27N. WIDESPREAD DRY AIR EXISTS S OF THERE.
MUCH OF THIS MOISTURE THEN CURVES AROUND THE BASE OF A HIGHLY
ELONGATED UPPER TROUGH NEAR 32N33W. THIS UPPER TROUGH SUPPORTS A
WEAKENING COLD FRONT ALONG 32N37W 24N56W. ANOTHER ELONGATED
UPPER TROUGH EXTENDS WSW FROM THE CAPE VERDE ISLANDS TO NE SOUTH
AMERICA...BUT IS NOT GENERATING ANY SIGNIFICANT WEATHER. A WEAK
1012 MB LOW IS LOCATED JUST N OF THE CANARY ISLANDS WITH A COLD
FRONT EXTENDING SW FROM THE LOW TO 23N22W THEN BACK N AS A WARM
FRONT TO 32N32W. WEAK SFC RIDGING LIES TO THE S OF THE FRONTS
MENTIONED...A 1016 MB HIGH IS CENTERED NEAR 20N33W...A 1017 MB
NEAR 21N57W AND A 1017 MB NEAR HISPANIOLA. TROUGH BETWEEN THE
FORMER TWO HIGHS IS ALONG 21N45W 16N53W. THE WEAK RIDGING ALONG
WITH LARGE FRONTAL BOUNDARIES HAVE CREATED A WEAK SFC PATTERN
ACROSS MUCH OF THE ATLC.

$$
WILLIS/CANGIALOSI




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