[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 151742
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE 15 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 3N0 2S15W 4S24W 7S33W 6S43W. WITH
THE ITCZ HAVING SUCH A SRN POSITION...THE BULK OF THE DEEP
CONVECTION IS S OF THE EQUATOR. A SFC TROF EXTENDS NE OF THE
AMAZON DELTA ALONG 1N52W 4N40W WITH SCATTERED MODERATE
CONVECTION WITHIN 90 NM OF THE AXIS.

...DISCUSSION...

GULF OF MEXICO...
SFC RIDGING IS BUILDING BACK OVER THE AREA FROM THE NE WITH THE
FLOW MAINLY FROM THE E/SE. A WEAKENING FRONTAL TROF LIES WITHIN
THE RIDGE AND IS PUSHING SLOWLY NWD OVER N FL AND THE NE GULF
ALONG 31N79W 28N86W. WIDESPREAD LOW CLOUDS AND FOG EXTEND N OF
THE TROF ACROSS THE FL PANHANDLE AND S GA...AS WELL AS FARTHER W
FROM SRN AL TO SE TX IN THE MOIST SLY FLOW BUT THIS WESTERN AREA
APPEARS TO BE ERODING WITH DAYTIME HEATING. WESTERLY ZONAL FLOW
IN THE UPPER LEVELS IS ADVECTING DRY MID/UPPER LEVEL AIR EWD
FROM MEXICO AND IS HELPING TO PRODUCE PRIMARILY FAIR SKIES
ACROSS THE REST OF THE GULF WATERS. HOWEVER...WEAK SFC TROUGHING
IS ALIGNED ALONG THE E SLOPES OF THE SIERRA MADRES AT THE MOMENT
AND CONVERGENCE IS PRODUCING A FEW LOW CLOUDS WITHIN 60 NM OF
THE MEXICAN COAST S OF 23N. A COLD FRONT WILL MOVE OFF THE GULF
COAST WED NIGHT AND WILL STALL FROM THE FL STRAITS TO THE NW
GULF BY THU NIGHT/FRI MORNING...ULTIMATELY BRINGING ONLY
SLIGHTLY COOLER TEMPS TO THE AREA ON THU.

CARIBBEAN...
TAIL END OF AN ATLC FRONTAL TROF IS BEING DRAGGED WWD ACROSS THE
NRN LEEWARD ISLANDS BY THE EASTERLY TRADES WITH AN AREA OF
SCATTERED SHOWERS S OF HISPANIOLA FROM 14N-18N BETWEEN 67W-77W.
A SECOND PATCH OF SCATTERED SHOWERS HAS BEEN MOVING CONTINUOUSLY
ACROSS THE CARIBBEAN WATERS AND IS NOW OVER THE GULF OF HONDURAS
FROM 16N-22N BETWEEN 83W-87W. A 1010 MB LOW IS LOCATED ALONG THE
COAST OF COLOMBIA NEAR BARRANQUILLA WITH STRONG CYCLONIC
ROTATION OBSERVED IN THE SW CARIBBEAN CLOUD FIELD...BUT THERE
ARE NO SIGNIFICANT DYNAMICS TO SUPPORT MUCH SHOWER ACTIVITY. THE
MID/UPPER LEVELS REMAIN QUITE DRY AND THUS IS PRECLUDING ANY
DEEP CONVECTION...ALTHOUGH AN UPPER RIDGE ALONG CNTRL AMERICA IS
BEGINNING TO BRING A FEW HIGH CLOUDS OVER FROM THE PACIFIC. MOST
OF THE SHOWERS OVER OPEN WATERS WILL CONTINUE TO MOVE TO THE
W...AFFECTING PARTS OF CNTRL AMERICA THRU FRI.

WEST/CENTRAL ATLANTIC...
A WEAK COLD FRONT HAS MOVED OFF THE U.S. EAST COAST WITH THE
TAIL END LAGGING AS A FRONTAL TROF FROM 31N78W SW ACROSS CNTRL
FL. ISOLATED SHOWERS ARE OCCURRING E OF JACKSONVILLE FL WITHIN
45 NM OF THE TROF BUT A STRENGTHENING SFC RIDGE OVER THE W ATLC
WATERS IS KEEPING THIS ACTIVITY MOSTLY N OF THE AREA. FARTHER
E...A CUT-OFF UPPER LOW IS LOCATED N OF THE AREA NEAR 38N44W AND
IS PRODUCING A LARGE AREA OF UPPER LEVEL WESTERLIES ACROSS THE
AREA WITH A SHORTWAVE MOVING EWD ALONG 45W. THIS SHORTWAVE IS
HELPING TO PUSH A COLD FRONT TO THE E ALONG 32N39W 27N43W BUT IS
BEGINNING TO HANG UP FARTHER SW TO 23N55W 17N62W. SCATTERED
SHOWERS EXTEND UP TO 200 NM BEHIND THE FRONT E OF 60W WITH
ISOLATED MODERATE CONVECTION FORMING ALONG THE IMMEDIATE FRONT N
OF 25N. COLD AIR STRATOCUMULUS IS PLUNGING SWD BEHIND THE
FRONT...MOVING TO 28.5N BETWEEN 43W-63W. THE TROPICS ARE LARGELY
UNDER A FAIR-WEATHER TYPE OF REGIME WITH WEAK EASTERLIES AND
PATCHY CLOUDS BUT A SFC TROF EXTENDING ALONG 1N52W 4N41W IS
PRODUCING SCATTERED MODERATE CONVECTION WITHIN 90 NM OF THE AXIS.

EAST ATLANTIC...
A DEEP-LAYERED LOW REMAINS CENTERED W OF THE CANARY AND MADEIRA
ISLANDS WITH A 1007 MB SFC REFLECTION CENTERED NEAR 30N23W. THE
FLOW AROUND THE LOW HAS BECOME MOSTLY CIRCULAR AND SO THERE ARE
NO FRONTS TO SUPPORT MUCH PRECIPITATION. ISOLATED SHOWERS ARE
LOCATED OVER THE N SEMICIRCLE N OF 31N BETWEEN 14W-30W BUT EVEN
THIS ACTIVITY WILL DIMINISH AS THE LOW WINDS DOWN. A NARROW
SWATH OF DUST/SAND IS STILL BEING WRAPPED INTO THE N/E SIDE OF
THE LOW EXTENDING FROM WESTERN SAHARA NWD ACROSS THE EASTERNMOST
CANARY ISLANDS THEN TO MADEIRA ISLAND. FARTHER S...STRONG N/NELY
FLOW AT THE SFC HAS PUSHED THE ITCZ AND ALL ITS ASSOCIATED
CONVECTION S OF THE EQUATOR ALTHOUGH THE SUBTROPICAL JET IS
ADVECTING MID/HIGH LEVEL CLOUDS EWD IN A BAND BETWEEN THE
EQUATOR AND 10N.

$$
BERG




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