[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 141737
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 1N1W 2N16W 4N27W 2N43W 3N52W.
SCATTERED MODERATE WITHIN 60 NM OF AXIS BETWEEN 25W-35W.  WIDELY
SCATTERED MODERATE WITHIN 45 NM OF AXIS BETWEEN 17W AND 23W.
ISOLATED MODERATE S OF 2N E OF 3W.

...DISCUSSION...

GULF OF MEXICO...
STRONG MID/UPPER LEVEL TROUGH IS SWINGING THRU THE E GULF OF
MEXICO... HELPING TO FIRE A BROKEN SQUALL LINE FROM ABOUT LAKE
OKEECHOBEE THRU THE WESTERN FL KEYS INTO W CUBA.  SOME STORMS
COULD APPROACH SEVERE CRITERIA WITH STRONG UPPER DYNAMICS...
DEEP TROPICAL MOISTURE AND MODEST LOW-LEVEL SHEAR VALUES.  COLD
FRONT LAGS THE SQUALL LINE BY ABOUT 90 NM THRU ABOUT
JACKSONVILLE TO TAMPA THEN BETWEEN MERIDA AND COZUMEL IN
MEXICO.  OVERCAST RAIN WITH TSTMS ON THE LEADING EDGE BLANKETS
MOST OF THE FLORIDA PENINSULA EXCEPT FOR THE FAR SE PART.  A
STATIONARY FRONT REMAINS ALONG THE E SIDE OF THE SIERRA MADRE
MOUNTAINS. STRONG SUBSIDENCE IS BEHIND THE TROUGH WITH DRY ZONAL
FLOW WESTWARD TO NE MEXICO.  BROKEN LOW CLOUDS ARE W OF 85W...
BREAKING UP AND BECOMING MORE SCATTERED IN THE BAY OF CAMPECHE
AND W GULF.  FRONT SHOULD CLEAR FLORIDA OVERNIGHT WITH DRIER AIR
SLOWLY FILTERING DOWN THE PENINSULA.  A LONG STRETCH OF PLEASANT
WEATHER LOOKS LIKELY FOR THE GULF COAST BEYOND THE WEEKEND WITH
GENERALLY NLY WINDS SENDING DRY CONTINENTAL AIR ACROSS THE
REGION.

CARIBBEAN...
MID/UPPER LEVEL RIDGING EXTENDS FROM NW COLOMBIA TO THE CAYMAN
ISLANDS.. JUST AHEAD OF THE INCOMING TROUGH FROM THE GULF OF
MEXICO.  A FEW TSTMS ARE ALONG THE SOUTHERN EDGE OF THE SQUALL
LINE NEAR THE ISLE OF PINES AS OTHER TSTMS FORM WITHIN 45 NM OF
A LINE FROM THE ISLE OF PINES TO 16N86W NEAR ROATAN.   THE COLD
FRONT IS EXPECTED TO MAKE ITS WAY INTO THE CARIBBEAN OVERNIGHT
AND SHOULD HAVE SCATTERED SHOWERS NEAR AND BEHIND THE FRONT.
SLIGHTLY DIFFLUENT UPPER FLOW EMERGES FROM CENTRAL AMERICA NEAR
NICARAGUA... SUPPORTING ISOLATED MODERATE CONVECTION WITHIN 60
NM OF 12N83W.   THE E CARIBBEAN IS UNDER THE INFLUENCE OF
TROUGHING FROM THE SUBTROPICAL ATLC WITH DRY AIR/SUBSIDENCE
LIMITING ANY CONVECTION SAVE THE WINDWARD ISLANDS... WHERE A
LOW-LEVEL TROUGH ALONG WITH MORE DIVERGENT FLOW ALOFT IS CAUSING
WIDELY SCATTERED SHOWERS S OF BARBADOS.  THE WETTEST WEATHER
SHOULD STAY IN THE SE CARIBBEAN WITH CONDITIONS STAYING MORE
CLIMATOLOGICAL IN THE NE CARIBBEAN.

ATLANTIC OCEAN...
THE MID/UPPER LEVEL PATTERN OVER THE SUBTROPICAL ATLC CONSISTS
OF A RIDGE OVER THE W ATLC AND A BROAD TROUGH ACROSS THE
REMAINDER. MID/UPPER LEVEL HIGH IS OVER THE W ATLC NEAR 28N70W
WITH A HIGH AMPLITUDE RIDGE AXIS EXTENDING NNE TO BEYOND 32N68W.
THIS IS PRODUCING STRONG SUBSIDENCE AND VERY STABLE AIR OVER THE
W ATLC W OF 60W WHICH IS BEGINNING TO CHANGE AS THE FRONTAL
SYSTEM IN THE GULF MOVES INTO THE W ATLC.  SCATTERED TSTMS ARE N
OF 28N W OF 79W NEAR AND BEHIND A SQUALL LINE.  BROAD MID/UPPER
TROUGH COVERS THE CENTRAL AND E ATLC WITH AXIS FROM 31N28W TO
27N43W THEN WSW INTO THE FAR SE BAHAMAS.  DRY AIR ALOFT IS
PREVENTING MOST TSTM ACTIVITY WHICH IS CONFINED TO THE ITCZ.
ISOLATED SHOWERS ARE POPPING UP IN THE CYCLONIC FLOW FROM THE
TROUGH NEAR 21N53W PLUS 27N46W.  AT THE SURFACE... LARGE STRONG
1038 MB HIGH CONTROLS THE REGION WITH STRONG TRADEWINDS
APPROACHING 30 KT IN THE CENTRAL ATLC WITH A TIGHT PRESSURE
GRADIENT.  COLD FRONT ENTERS THE E ATLC NEAR 31N25W DISSIPATING
TO 27N36W WITH OVERCAST LOW CLOUDS AND POSSIBLE SHOWERS WITHIN
60 NM OF THE FRONT.  IN THE TROPICAL ATLC... MOIST ZONAL FLOW
ALOFT DOMINATES THE REGION WITH WIDELY SCATTERED SHOWERS AND A
FEW TSTMS S OF 12N W OF 50W DUE TO A SURFACE TROUGH FROM 8N56W
TO JUST W OF BARBADOS.  HIGH CLOUDS ARE BROKEN ACROSS A GOOD
PORTION OF THE DEEP TROPICS S OF 15N WITH CONVECTIVE-DEBRIS
CLOUDS.  THE ITCZ IS QUITE CONVECTIVELY-ACTIVE WITH STRONG
DIVERGENCE ALOFT ENHANCING THE TSTMS.  THE PATTERN WILL BE
CHANGING IN THE REGION WITH RIDGING GROWING IN THE CENTRAL ATLC
AND A CUTOFF LOW FORMING IN THE NE ATLC.

$$
BLAKE

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