000 AXNT20 KNHC 191728 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON OCT 19 2009 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 24W/25W S OF 19N MOVING W NEAR 10 KT. THE WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM ACROSS THE EASTERN TROPICAL ATLC AS OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. GLOBAL MODEL GUIDANCE FIELDS OF 850 MB RELATIVE VORTICITY AND 700 MB STREAMLINES ALSO DEPICT CYCLONIC TURNING IN THE VICINITY OF THE WAVE AXIS BETWEEN 22W-28W. SCATTERED SHOWERS ARE FROM 10N-20N BETWEEN 16W-24W. A 1010 MB LOW IS INTRODUCED NEAR 11N34W BASED ON VISIBLE SATELLITE IMAGERY. THE LOW IS MOVING W AT 5 KT AND APPEARS TO HAVE BEEN LEFT BEHIND BY THE TROPICAL WAVE AT 39W. ISOLATED MODERATE CONVECTION IS FROM 8N-13N BETWEEN 30W-34W. TROPICAL WAVE IS ALONG 39W S OF 16N MOVING W NEAR 10 KT. THE WAVE COINCIDES WITH THE LEADING EDGE OF A DEEP LAYER MOISTURE MAXIMUM OBSERVED ACROSS THE EASTERN TROPICAL ATLC E OF 42W IN TOTAL PRECIPITABLE WATER IMAGERY. CIMSS WAVETRAK MODEL GUIDANCE ALSO DEPICTS A MAXIMUM IN 850 MB RELATIVE VORTICITY FOCUSED ON THE NORTHERN EXTENT OF THE WAVE N OF 8N. ISOLATED SHOWERS ARE FROM 6N-16N BETWEEN 37W-41W. TROPICAL WAVE IS ALONG 62W/63W S OF 13N MOVING W NEAR 15 KT. AN AREA OF DEEP LAYER MOISTURE IS PROPAGATING WWD ACROSS EASTERN VENEZUELA AND PORTIONS OF THE TROPICAL NORTH ATLC S OF 11N BETWEEN 57W-64W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 6N16W 15N24W 8N40W 6N50W 6N58W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION...SCATTERED SHOWERS ARE FROM 3N-7N BETWEEN 10W-20W...AND FROM 4N-10N BETWEEN 20W-24W. ...DISCUSSION... GULF OF MEXICO... A 1029 MB HIGH CENTERED OVER N ALABAMA NEAR 34N88W IS PRODUCING SURFACE RIDGING OVER THE ENTIRE GULF OF MEXICO. 15-20 KT NE WINDS ARE OVER THE E GULF E OF 90W WHILE 10 KT SE WINDS ARE OVER THE W GULF. BROKEN TO OVERCAST COLD AIR STRATOCUMULUS CLOUDS ARE OVER THE MAJORITY OF THE GULF S OF 29N. COOL OVERNIGHT TEMPERATURES OVER FLORIDA HAVE NOW WARMED UP WITH DIURNAL HEATING. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE ENTIRE GULF OF MEXICO AND NW CARIBBEAN SUPPORTING THE SURFACE COLD FRONT. STRONG SUBSIDENCE IS OVER THE GULF EXCEPT OVER THE SW GULF S OF 22N WHERE CONSIDERABLE UPPER LEVEL MOISTURE IS NOTED. EXPECT...THE SURFACE HIGH TO MOVE E AND CONTINUE TO PRODUCE SURFACE RIDGING WITH A DRY STABLE AIRMASS OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A TROPICAL WAVE IS ALONG 62W/63W PRODUCING CONVECTION NEAR TRINIDAD AND NE VENEZUELA. SEE ABOVE. A SLOW MOVING COLD FRONT EXTENDS FROM E CUBA TO NE HONDURAS ALONG 20N74W 18N82W 15N85W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE FRONT. 25 KT NORTHERLY WINDS ARE OVER THE YUCATAN CHANNEL AND NW CARIBBEAN N OF THE COLD FRONT. GENTLE BREEZE TRADEWINDS ARE JUST S OF THE COLD FRONT. FRESH TRADEWINDS ARE OVER THE CENTRAL AND E CARIBBEAN E OF 80W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS S OF JAMAICA FROM 13N-18N BETWEEN 77W-81W. A QUASI-STATIONARY 1009 MB LOW IS CENTERED OVER THE SW CARIBBEAN NEAR 11N81W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 8N-13N BETWEEN 80W-83W. ISOLATED SHOWERS ARE S OF HISPANIOLA AND PUERTO RICO FROM 14N-18N BETWEEN 64W-74W. IN THE UPPER LEVELS... AN UPPER LEVEL TROUGH IS OVER THE NW CARIBBEAN N OF 17N AND W OF 80W. AN UPPER LEVEL RIDGE IS OVER THE SW CARIBBEAN W OF 70W. AN UPPER LEVEL LOW IS CENTERED OVER THE LESSER ANTILLES NEAR 15N61W. SIGNIFICANT UPPER LEVEL MOISTURE IS OVER THE W CARIBBEAN W OF 70W. STRONG SUBSIDENCE IS OVER THE E CARIBBEAN. EXPECT...THE FRONT TO BECOME STATIONARY AND DISSIPATE OVER THE NEXT 24 HOURS. EXPECT THE TROPICAL WAVE TO MOVE W AND PRODUCE MORE CONVECTION OVER THE SW CARIBBEAN. ALSO EXPECT THE SURFACE LOW TO BE STATIONARY OVER THE SW CARIBBEAN AND DEEPEN SLIGHTLY WITH CONVECTION. ATLANTIC OCEAN... A STATIONARY FRONT ENTERS THE DISCUSSION AREA NEAR 32N67W AND EXTENDS SW TO E CUBA NEAR 20N74W. ISOLATED MODERATE CONVECTION IS WITHIN 60 NM OF THE FRONT. A 1024 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 34N53W. A SURFACE TROUGH IS FURTHER E FROM 32N44W TO 25N46W 15N49W. SCATTERED SHOWERS ARE WITHIN 45 NM OF THE TROUGH. ANOTHER SURFACE TROUGH IS OVER THE E ATLANTIC ALONG 31N28W 27N30W. A WEAK 1020 MB HIGH IS FURTHER E NEAR 27N25W. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE W ATLANTIC N OF 24N AND W OF 70W. AN UPPER LEVEL RIDGE IS BETWEEN 55W-70W. AN UPPER LEVEL LOW IS OVER THE CENTRAL ATLANTIC NEAR 26N40W. ANOTHER UPPER LEVEL LOW IS CENTERED NE OF THE CANARY ISLANDS NEAR 31N9W. AN UPPER LEVEL HIGH IS OFF THE COAST OF WEST AFRICA NEAR 13N20W. EXPECT...MORE CONVECTION ALONG THE ITCZ ESPECIALLY E OF 40W OVER THE NEXT 24 HOURS. $$ FORMOSA