000 ABPZ30 KNHC 011400 TWSEP MONTHLY TROPICAL WEATHER SUMMARY NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 800 AM PDT WED AUG 1 2007 FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE.. TROPICAL CYCLONE ACTIVITY IN THE EASTERN PACIFIC OCEAN WAS BELOW AVERAGE FOR JULY. HURRICANE COSME...TROPICAL STORM DALILA...AND TROPICAL STORM ERICK FORMED IN THE EASTERN PACIFIC DURING THE MONTH. IN COMPARISON...THE AVERAGE JULY HAS ABOUT FOUR TROPICAL STORMS...TWO OF WHICH BECOME HURRICANES. TROPICAL DEPRESSIONS FOUR-E AND FIVE-E ALSO DEVELOPED DURING THE MONTH. SO FAR IN 2007...THERE HAVE BEEN A TOTAL OF 5 TROPICAL STORMS...1 HURRICANE...AND NO MAJOR HURRICANES. THESE TOTALS ARE WELL BELOW THE CLIMATOLOGICAL AVERAGE OF 6.2 TROPICAL STORMS... 3.0 HURRICANES AND 1.5 MAJOR HURRICANES BY THE END OF JULY. IN FACT...IN TERMS OF ACCUMULATED CYCLONE ENERGY (ACE)...THIS IS THE THIRD QUIETEST YEAR-TO-DATE (BEHIND 2005 AND 1966) SINCE THE GEOSTATIONARY SATELLITE ERA BEGAN IN 1966. TROPICAL DEPRESSION FOUR-E WAS SPAWNED BY A TROPICAL WAVE THAT EMERGED FROM THE COAST OF AFRICA ON 23 JUNE AND REACHED THE PACIFIC ON 3 JULY. THE ASSOCIATED CONVECTION INCREASED ON 6 JULY AND BEGAN TO SHOW SIGNS OF ORGANIZATION THE NEXT DAY. A DEPRESSION FORMED LATE ON 9 JULY ABOUT 615 N MI SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. A COMBINATION OF SOUTHWESTERLY VERTICAL WIND SHEAR AND DECREASING SEA SURFACE TEMPERATURES ALONG THE TRACK PREVENTED ADDITIONAL STRENGTHENING AS THE CYCLONE MOVED NORTHWESTWARD. THE SYSTEM TURNED WESTWARD LATE ON 10 JULY...AND IT WEAKENED TO A NON-CONVECTIVE REMNANT LOW EARLY THE NEXT DAY ABOUT 765 N MI WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. TROPICAL DEPRESSION FIVE-E DEVELOPED FROM A TROPICAL WAVE THAT MOVED OFF THE WEST COAST OF AFRICA ON 21 JUNE AND ENTERED THE EASTERN NORTH PACIFIC AROUND 10 JULY. DISORGANIZED CONVECTION ASSOCIATED WITH THE WAVE INCREASED ON 11 JULY. THE WAVE MOVED WESTWARD AND GRADUALLY BECAME BETTER ORGANIZED OVER THE NEXT COUPLE OF DAYS, AND A DEPRESSION FORMED AT 1200 UTC 14 JULY, ABOUT 600 N MI SOUTH-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. UNDER THE INFLUENCE OF VERTICAL SHEAR, THE DEPRESSION WAS UNABLE TO STRENGTHEN FURTHER. THE CYCLONE CONTINUED WEST-NORTHWESTWARD ON 15 JULY, AND COOLER WATERS AND A MORE STABLE AIRMASS RESULTED IN IT DEGENERATING INTO A REMNANT LOW AT 0000 UTC 16 JULY. COSME ORIGINATED FROM A TROPICAL WAVE THAT WAS DIFFICULT TO TRACK ACROSS THE ATLANTIC AND CARIBBEAN SEA DUE TO THE LACK OF CONVECTIVE ACTIVITY. THE WAVE WAS ESTIMATED TO ENTER THE EASTERN NORTH PACIFIC BASIN AROUND 8 JULY...AND SHOWED SIGNS OF ORGANIZATION STARTING ON 10 JULY. A TROPICAL DEPRESSION FORMED FROM THE SYSTEM ON 14 JULY ABOUT 1725 N MI EAST-SOUTHEAST OF HILO HAWAII. THE DEPRESSION WAS COMPRISED OF A VERY LARGE CIRCULATION AND INITIALLY MOVED SLOWLY TOWARD THE NORTHWEST IN RESPONSE TO A WEAKNESS IN THE RIDGE TO THE NORTH. THE DEPRESSION WAS UPGRADED TO TROPICAL STORM COSME ON 15 JULY...AND WITH BOTH THE ATMOSPHERIC AND OCEANIC ENVIRONMENT CONDUCIVE FOR STRENGTHENING COSME REACHED HURRICANE STRENGTH 24 HOURS LATER ABOUT 1400 N MI EAST OF HILO HAWAII. BY EARLY ON 17 JULY...THE CYCLONE MOVED MORE TOWARD THE WEST IN RESPONSE TO A STRENGTHENING RIDGE TO THE NORTH. BY THIS TIME COSME WAS IN AN ENVIRONMENT OF MODERATE EASTERLY SHEAR AND WATERS AROUND 25 DEGREES CELSIUS...AND THE HURRICANE WEAKENED TO A TROPICAL STORM ON 17 JULY. THE CYCLONE CONTINUED TO SLOWLY WEAKEN AS IT MOVED WESTWARD AND WAS DOWNGRADED TO A TROPICAL DEPRESSION LATE IN THE DAY ON 18 JULY...JUST PRIOR TO CROSSING INTO THE CENTRAL PACIFIC BASIN. DALILA DEVELOPED FROM A TROPICAL WAVE THAT ENTERED THE EASTERN PACIFIC OCEAN ON 17 JULY. THE WAVE SPAWNED A BROAD LOW PRESSURE AREA SOUTH OF THE GULF OF TEHUANTEPEC ON 19 JULY. THE BROAD LOW MOVED SLOWLY WESTWARD AND THE ASSOCIATED THUNDERSTORM ACTIVITY INCREASED ON 21 JULY. THE SYSTEM ACQUIRED ENOUGH ORGANIZATION EARLY ON 22 JULY TO BE CLASSIFIED AS A TROPICAL DEPRESSION...WHILE LOCATED ABOUT 400 N MI SOUTH OF MANZANILLO MEXICO. NORTHEASTERLY SHEAR INITIALLY INHIBITED SIGNIFICANT STRENGTHENING. HOWEVER... EARLY ON 23 JULY...THE DEPRESSION WAS ABLE TO REACH TROPICAL STORM STRENGTH. A RIDGE OVER NORTHERN MEXICO STEERED DALILA NORTHWESTWARD DURING THE NEXT FEW DAYS. THE CYCLONE REACHED A PEAK INTENSITY OF 50 KT ON 25 JULY WHILE CENTERED ABOUT 50 N MI SOUTHEAST OF SOCORRO ISLAND. AFTER PASSING VERY NEAR SOCORRO ISLAND...DALILA BEGAN MOVING OVER COOLER WATERS WHICH INITIATED WEAKENING. ON 26 JULY...WHILE LOCATED ABOUT 210 N MI SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA THE TROPICAL CYCLONE TURNED WEST-NORTHWESTWARD AND WEAKENED TO A TROPICAL DEPRESSION EARLY THE NEXT DAY. DALILA DEGENERATED TO A REMNANT LOW ON 27 JULY...ABOUT 400 N MI WEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. THE REMNANT LOW MOVED WEST-NORTHWESTWARD DURING THE NEXT FEW DAYS AND DISSIPATED ON 30 JULY. ERICK FORMED FROM A TROPICAL WAVE THAT ENTERED THE EASTERN PACIFIC ON 23 JULY. THE WAVE GRADUALLY BECAME BETTER ORGANIZED...FORMING A BROAD SURFACE LOW ALONG THE WAVE ON 28 JULY. THUNDERSTORM ACTIVITY CONSOLIDATED NEAR THE LOW ON 31 JULY AND ORGANIZED INTO A TROPICAL DEPRESSION LATE IN THE DAY...LOCATED ABOUT 960 NM SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. THE DEPRESSION BECAME A TROPICAL STORM EARLY ON 1 AUGUST AND AT THE TIME OF THIS WRITING WAS LOCATED ABOUT 1075 NM WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. SUMMARY TABLE NAME DATES MAX WIND (KT) DEATHS ------------------------------------------------------- TD FOUR-E 9-11 JUL 30 0 TD FIVE-E 14-15 JUL 30 0 H COSME 14-23 JUL 65 0 TS DALILA 22-27 JUL 50 0 TS ERICK 31 JUL- 35 0 ------------------------------------------------------- NOTE...DATES BASED ON COORDINATED UNIVERSAL TIME (UTC) $$ FORECASTER BLAKE/MAINELLI/RHOME/BROWN