000 AXNT20 KNHC 151753 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST TUE JAN 15 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N12W 3N20W ALONG THE EQUATOR BETWEEN 30W AND 44W INTO NE BRAZIL. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 2S-4N BETWEEN 44W-50W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 100 NM N OF AXIS BETWEEN 23W-29W. ...DISCUSSION... GULF OF MEXICO... ATTENTION REMAINS FOCUSED IN A DEVELOPING 1012 MB SURFACE LOW LOCATED OVER THE SW PORTION OF THE GULF NEAR 21N96W. THIS LOW IS FORECAST TO STRENGTHEN TO A GALE IN ABOUT 24 HOURS OR SO. THIS SYSTEM IS ALREADY TAKING SHAPE ON SATELLITE IMAGERY THAT SHOWS SOME CYCLONIC SIGNATURE WITH MOST OF THE SHOWER/TSTM ACTIVITY TO THE E AND NE OF THE LOW CENTER. A STRONG CUT-OFF LOW MOVING EWD OVER NORTHERN MEXICO IS SUPPORTING THE DEVELOPMENT OF THIS GALE THAT IS FORECAST TO MOVE NE ACROSS THE WESTERN GULF...THEN EWD OVER THE NORTHERN GULF WATERS REACHING THE FLORIDA PANHANDLE EARLY THU. A GALE WARNING HAS BEEN ISSUED FOR THE NORTHERN PORTION OF THE GULF OF MEXICO. A STATIONARY FRONT REMAINS ATTACHED TO THE LOW AND CROSSES THE N YUCATAN PENINSULA/CHANNEL AND THE BAY OF CAMPECHE. THE LOW WILL DRAG A NEW COLD FRONT ACROSS THE GULF WED AND THU WITH THE FRONT STALLING OVER THE SE WATERS THU NIGHT. A SFC TROUGH WAS ANALYZED OVER THE WRN GULF OF MEXICO FROM THE SFC LOW TO THE UPPER TEXAS COAST. MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS COVERS A GOOD PORTION OF THE AREA. THE REMAINDER OF THE AREA IS UNDER THE INFLUENCE OF A BUILDING LOW-LEVEL RIDGE WITH SEVERAL CENTERS OVER THE SE U.S. ALONG THE GULF COAST STATES. THE STRONG PRESSURE GRADIENT BETWEEN THE BUILDING SFC RIDGE AND LOW PRESSURE OVER THE SW GULF IS PRODUCING MODERATE TO STRONG ELY WINDS ACROSS THE AREA MAINLY W OF 90W. OTHERWISE...AT UPPER LEVELS...STRONG SWLY WINDS ARE ADVECTING UPPER LEVEL MOISTURE/HIGH CLOUDS FROM THE EPAC ACROSS CENTRAL MEXICO INTO THE GULF AND THE FLORIDA PENINSULA. CARIBBEAN SEA... A MID-LEVEL RIDGE NOW CENTERED JUST NE OF HISPANIOLA CONTINUES TO DOMINATE MOST OF THE BASIN LIMITING THE DEVELOPMENT OF DEEP CONVECTION. HOWEVER...THERE ARE SOME PATCHES OF LOW-LEVEL CLOUDS WITH EMBEDDED SHOWERS FORMING OVER THE WESTERN CARIBBEAN WITHIN A BROAD CYCLONIC FLOW. THESE CLOUDS ARE AFFECTING FROM WESTERN PANAMA TO HONDURAS. ELSEWHERE...A STATIONARY FRONT LIES ACROSS WESTERN CUBA AND THE YUCATAN CHANNEL/PENINSULA GENERATING SOME CLOUDINESS AND A FEW SHOWERS. EARLY TRADE WINDS BLOWING ACROSS THE REMAINDER OF THE CARIBBEAN ARE MOSTLY MODERATE IN STRENGTH...EXCEPT LOCALLY STRONGER IN THE TYPICAL ZONE NEAR THE COAST OF COLOMBIA. EXPECT THE FRONTAL BOUNDARY TO WEAKEN ACROSS THE CARIBBEAN. THE NEXT COLD IS FORECAST TO REACH THE YUCATAN CHANNEL/WESTERN CUBA LATE SAT WITH STRONG NORTHERLY WINDS BEHIND IT. TO THE EAST...A BROAD UPPER-LEVEL RIDGE DOMINATING NRN SOUTH AMERICA IS ADVECTING MOISTURE/HIGH CLOUDS INTO THE SE CARIBBEAN. ATLANTIC OCEAN... A COLD FRONT PASSES SE OF BERMUDAS ENTERING THE AREA NEAR 31N33W THEN CONTINUES SW ACROSS THE CENTRAL BAHAMAS NEAR 25N75W. AT THIS POINT IT BECOMES STATIONARY CROSSING WESTERN CUBA AND THE EXTREME NW CARIBBEAN. THE FRONTAL BOUNDARY IS WELL DEFINED ON SATELLITE PICTURES NE OF THE BAHAMAS WITH A 70-100 NM WIDE BAND OF LOW/MID CLOUDS AND SCATTERED SHOWERS. AHEAD OF THE FRONT... THERE IS A SFC TROUGH THAT RUNS FROM 28N56W TO 20N60W. ANOTHER SFC TROUGH WAS ADDED TO THE 12Z SURFACE MAP ALONG 12N37W 9N42W BASED ON A QUIKSCAT PASS FROM THIS MORNING THAT SHOWED THE WIND SHIFT ASSOCIATED WITH THE TROUGH. SOME SHOWER/TSTM ACTIVITY IS ON THE TAIL END OF THE TROUGH AND WITHIN 145 NM SE OF THE NORTHERN END. UPPER-LEVEL DIFFLUENCE IS ENHANCING SOME SHOWER ACTIVITY ACROSS THE CENTRAL ATLC MAINLY N OF 19N BETWEEN 48W-51W. OTHERWISE...AN SE-MOVING SFC RIDGE...ANCHORED ON A 1030 MB HIGH CENTER NEAR 33N28W...DOMINATES THE REMAINDER OF THE ATLANTIC FORECAST AREA. MODERATE TO STRONG TRADES ON THE SOUTHERN SIDE OF THIS FEATURE ARE AFFECTING THE TROPICAL ATLANTIC FROM THE NWRN COAST OF AFRICA TO 50W. FINALLY...A JET STREAM BRANCH...WITH CORE WINDS OF 90 TO 110 KT IS SE OF AN AMPLIFIED MID TO UPPER TROUGH EXTENDING FROM A CUT-OFF LOW NEAR 23N32W TO 18N41W. A BROAD BAND OF TRANSVERSE HIGH CLOUDS... CROSSING THE CAPE VERDE ISLANDS...ACCOMPANIES THIS JET. $$ GR