[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 042339
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE MAR 04 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
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 2315 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N9W 3N21W 1N30W CROSSING THE
EQUATOR NEAR 35W TO 2S43W. SCATTERED MODERATE TO STRONG
CONVECTION IS WITHIN 180 NM EITHER SIDE OF AXIS BETWEEN 17W-21W
AND 30W-37W. SIMILAR CONVECTION IS FROM 1N-4N BETWEEN 37W-48W
AND FROM 4N-6N E OF 10W.

...DISCUSSION...
GULF OF MEXICO...
STRONG COLD FRONT...ASSOCIATED WITH A DEEP LAYER LOW PRES SYSTEM
OVER THE OHIO VALLEY...EXTENDS FROM THE FLORIDA PANHANDLE TO THE
YUCATAN PENINSULA ALONG 30N85W 21N88W. RADAR DATA INDICATES
LINES OF SCATTERED SHOWERS AND TSTMS N OF 24N E OF THE FRONT.
ISOLATED ACTIVITY EXISTS S OF 24N E OF THE FRONT. W OF THE
FRONT...GALE FORCE WINDS HAVE LIKELY ENDED OR WILL VERY SHORTLY
AS WEAK HIGH PRES HAS NOW ENTERED THE W GULF WATERS...GREATLY
RELAXING THE PRES GRADIENT. CLEAR SKIES ARE EVIDENT ON SATELLITE
IMAGES ACROSS THE NW WATERS DUE TO VERY DRY AIR ON THE BACK SIDE
OF THE DEEP LAYER LOW. LOOKING AHEAD A DAY OR SO...THE FRONT
WILL CONTINUE TO MOVE SE THROUGH EARLY TOMORROW AS IT WEAKENS.
THEREAFTER...IT WILL LIFT BACK TOWARD THE NW AS A WARM FRONT
WITH ATTENTION THEN DRAWN TO THE NEXT FRONT ENTERING THE NW GULF
LATE THU.

CARIBBEAN SEA...
WEAK UPPER SHORTWAVE EXTENDS FROM THE VIRGIN ISLANDS TOWARD THE
N SHORE OF COLOMBIA WHILE A MID TO UPPER RIDGE CONTROLS THE
PATTERN ALOFT IN THE W CARIB. WIDESPREAD SUBSIDENCE IS
ASSOCIATED WITH THESE UPPER SYSTEMS KEEPING THE TYPICAL
LOW-LEVEL MOISTURE PATCHES SHALLOW. VISIBLE/SW IR IMAGES
INDICATE THAT THE THICKEST CLOUD PATCHES ARE OVER THE NRN
LEEWARD ISLANDS AND MUCH OF THE CENTRAL PORTION N OF 14N BETWEEN
65W-78W. AS USUAL...ISOLATED TO SCATTERED QUICK MOVING SHOWERS
AND LOW TOPPED TSTMS ARE LIKELY EMBEDDED IN THESE PATCHES. A
COLD FRONT OVER THE WRN YUCATAN IS STILL MAKING SLOW E PROGRESS
BUT IT IS NOT EXPECTED TO MOVE MUCH FARTHER SE...SO LITTLE
IMPACT IS ANTICIPATED OVER THE NW WATERS. TRADE WINDS REMAIN ON
THE STRONG SIDE...ESPECIALLY IN THE TYPICAL ENHANCED ZONE NEAR
THE COLOMBIAN COAST WHERE SUSTAINED WINDS ARE TO 30 KT. THESE
CONDITIONS ARE EXPECTED TO CHANGE LITTLE OVER THE NEXT COUPLE OF
DAYS.

ATLANTIC OCEAN....
FAIRLY POTENT VERTICALLY STACKED LOW PRES SYSTEM OVER THE OHIO
VALLEY IS PRODUCING SCATTERED SHOWER AND TSTM ACTIVITY OVER AND
OFF THE ERN SEABOARD N OF 29N W OF 80W. THIS WILL SPREAD E BUT
LIKELY WEAKEN SOME LATER TONIGHT AND TOMORROW AS THE LOW AND ITS
ASSOCIATED FRONT MOVE OFFSHORE. A STACKED RIDGE LIES OVER THE W
ATLC WITH THE SFC CENTER ANALYZED 1030 MB NEAR 35N57W. FAIRLY
QUIET CONDITIONS ARE BENEATH THIS RIDGE EXCEPT FOR AN AREA OF
SCATTERED SHOWERS AND ISOLATED TSTMS FROM 24N-28N BETWEEN
62W-70W....LIKELY DUE TO A SMALL WEAK MID-LEVEL DISTURBANCE.  AN
UPPER LOW IS DROPPING S IN THE CENTRAL ATLC...STILL N OF THE
AREA NEAR 39N39W. A RELATED COLD FRONT CLIPS THE N PORTION OF
THE REGION EXTENDING FROM 32N36W TO 28N41W. LITTLE SIGNIFICANT
WEATHER IS ASSOCIATED WITH THE FRONT ITSELF...BUT THERE IS A
BAND OF SCATTERED SHOWERS N OF 27N BETWEEN 30W-35W IN AN UPPER
DIFFLUENT AREA. IN THE TROPICS...AN E-W STRETCHED RIDGE IS
CENTERED NEAR 4N23W. DIFFLUENCE ALOFT ASSOCIATED WITH THIS RIDGE
IS AIDING CONVECTION IN THE ITCZ. FOR MORE DETAILS SEE ABOVE.
STIFF WLY FLOW ALOFT AND A WEAK PRES PATTERN IS PROVIDING A VERY
TRANQUIL ENVIRONMENT FOR MUCH OF THE REGION N OF 10N E OF
40W.

$$
CANGIALOSI


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