000 AXNT20 KNHC 172331 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN FEB 17 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 ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N9W 3N30W 1S50W. ISOLATED SHOWERS/TSTMS WITHIN 120 NM OF AXIS BETWEEN 9W-23W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION S OF THE AXIS TO THE EQUATOR BETWEEN 24W-40W. SCATTERED MODERATE S OF 7N BETWEEN 43W-48W. ...DISCUSSION... GULF OF MEXICO... A DEEP LONGWAVE TROUGH IS CENTERED OVER THE CENTRAL PART OF NORTH AMERICA AND REACHES WELL INTO NORTHERN MEXICO AND THE GULF OF MEXICO. THE POLAR JET HAS PLUNGED WELL TO THE S AND EXTENDS FROM NEW MEXICO ACROSS TEXAS TO THE LOWER MISSISSIPPI VALLEY...AND HAS CONVERGED WITH A JET STREAK WITHIN THE SUBTROPICAL JET WHICH EXTENDS FROM NE MEXICO TO THE FLORIDA PANHANDLE. MAXIMUM UPPER LEVEL WINDS WITHIN THE JET ARE NEAR 95 KT ACROSS FAR S TEXAS AND THE NW GULF. A COLD FRONT ASSOCIATED WITH THIS TROUGH HAS PUSHED INTO THE N/CENTRAL GULF FROM NEAR MOBILE ALABAMA SW TO 26N94W BUT HAS BECOME NEARLY STATIONARY FARTHER SW TOWARDS VERACRUZ MEXICO. THE SOUTHERN PART OF THE FRONT IS QUICKLY WASHING OUT AND HAS SOMEWHAT MERGED WITH A TOPOGRAPHICALLY FORCED 1006 MB SURFACE LOW LOCATED NEAR 21N95W. A SQUALL LINE OF SCATTERED SHOWERS AND TSTMS LIES WITHIN 90 NM E OF THE FRONT N OF 27N AND SEVERAL SEVERE THUNDERSTORM AND TORNADO WARNINGS HAVE BEEN ISSUED FOR AREAS OF THE FLORIDA PANHANDLE...SE ALABAMA...AND WESTERN GEORGIA. A REINFORCING COLD FRONT LOCATED OVER SE TEXAS IS EXPECTED TO MOVE INTO THE GULF TONIGHT AND GIVE THE FIRST BOUNDARY AND EXTRA PUSH...MOVING E INTO THE E GULF AND FLORIDA BY MON. CARIBBEAN... AN UPPER LEVEL RIDGE AXIS IS CENTERED ALONG 76W WITH THE ASSOCIATED MID-LEVEL HIGH LOCATED BETWEEN JAMAICA AND THE CAYMAN ISLANDS. BROAD SOUTHERLY/SOUTHWESTERLY FLOW ALOFT IS DRAWING MOISTURE NWD FROM CONVECTION OVER THE E PACIFIC WATERS ACROSS CENTRAL AMERICA TOWARDS THE WESTERN GREATER ANTILLES. THIS IS PRIMARILY VISIBLE AS WIDESPREAD CIRRUS W OF THE UPPER RIDGE AXIS. FARTHER E...UPPER LEVEL WINDS ARE MORE CONFLUENT AND THUS STRONG SUBSIDENCE IS LOCATED OVER THE E CARIBBEAN ESPECIALLY OVER THE LESSER ANTILLES. OCCASIONAL PATCHES OF SHOWERS ARE MOVING WESTWARD ACROSS THE REGION IN THE TRADE WIND FLOW...WHICH IS GENERALLY IN THE 10-15 KT RANGE EXCEPT FOR 20-25 KT OFF THE COAST OF COLOMBIA. ONE PATCH OF SHOWERS IS CURRENTLY MOVING ACROSS THE VIRGIN ISLANDS AND PUERTO RICO AND WILL AFFECT HISPANIOLA LATER TONIGHT AND TOMORROW. SCATTERED SHOWERS/TSTMS ARE ALSO AFFECTING THE AREA FROM NORTHERN COLOMBIA WESTWARD ACROSS PANAMA AND COSTA RICA MAINLY DUE TO A NORTHWARD INFLECTION OF THE ITCZ. ATLANTIC... MUCH OF THE SUBTROPICAL AND TROPICAL ATLC IS DOMINATED BY AN UPPER RIDGE FROM THE BAHAMAS NORTHWARD ALONG 75W...AND AN EXPANSIVE TROUGH WHICH SPANS E OF 70W TO AFRICA. A SURFACE RIDGE IS LOCATED OVER THE W ATLC EXTENDING FROM BERMUDA TO N/CENTRAL FLORIDA WITH ISOLATED SHOWERS DOTTING THE LANDSCAPE. A COLD FRONT OVER THE CENTRAL ATLC HAS EASED INTO THE DISCUSSION AREA AND EXTENDS FROM 32N49W TO 30N54W TO 31N62W BUT IS ONLY ASSOCIATED WITH AN OVERCAST DECK OF LOW/MID LEVEL CLOUDS WITHIN 75 NM OF ITS BOUNDARY. FARTHER E...THE ISOBARIC PATTERN IS RATHER WEAK DUE TO A LARGE CUT-OFF LOW ENE OF THE AZORES. UPPER LEVEL FLOW E OF 40W IS SOUTHWESTERLY ALL THE WAY TO AFRICA AND THERE ARE TWO EMBEDDED JET CORES ASSOCIATED WITH THE SUBTROPICAL JET. THE SOUTHERNMOST ONE EXTENDS FROM 14N40W TO WESTERN SAHARA AND IS ASSOCIATED WITH A 400-NM WIDE SWATH OF CIRRUS WITH WINDS TO 85 KT. THE SECOND LIES FROM 28N30W PAST MADEIRA ISLAND TO NORTHERN MOROCCO WITH MAXIMUM WINDS OF 90 KT. FARTHER S IN THE TROPICS...SOUTHWESTERLY FLOW ALOFT IS PULLING MOISTURE NWD TO 10N WITH SCATTERED CONVECTIVE ACTIVITY FORMING IN THE VICINITY OF THE ITCZ. $$ BERG