| new tropical info Daily Summary: May 29: 1. Maps: HWM analyzes a closed low pressure of 1010 mb at 11.5N, 76.5W at 12Z. Microfilm does not show an organized system at 12Z. 2. Discussion: MWL: A tropical disturbance, which had been tracked northnortheastward from just north of Panama on May 29. May 30: 1. Maps: HWM analyzes a closed low pressure of 1010 mb at 11.0N, 78.0W at 12Z. Microfilm shows a spot low pressure near 13N, 78W at 12Z. May 31: 1. Maps: HWM analyzes a spot low pressure of 1010 mb at 16.8N, 79.8W at 12Z. Microfilm shows a closed low pressure at 18.0N, 79.5W at 12Z. 2. Discussion: MWL: Heavy rainfall was reported along the track of the disturbance with Santiago de Cuba receiving about 7.50 in. during a 2-day period in the incipient stage. Reanalysis: A tropical disturbance developed over the southern Caribbean Sea late in May and slowly moved northward. The system began to become better organized just south of Cuba late on May 31st. June 1: 1. Maps: HWM analyzes a closed low pressure of 1010 mb at 26.0N, 77.0W with a weakening frontal boundary to the north at 12Z. Microfilm shows a closed low pressure of at most 1008 mb at 26.0N, 78.0W at 12Z. 2. Ship highlights: 35 kt SE and 1009 mb at 26.0N, 74.0W at 12Z (micro). 35 kt SE and 1012 mb at 27.2N, 74.7W at 15Z (micro). 3. Discussion: MWL: Developed a closed sea level circulation over the northwestern Bahamas during the afternoon hours of June 1. Reanalysis: The disturbance crossed Cuba early on June 1st as a trough over into the western Bahamas. Synoptic observations indicate that a well-defined center developed around 12Z. The 500 mb analysis shows an upper-level low directly over the system, this system likely was a subtropical cyclone. However, without satellite imagery available to determine the convective structure, the system will be included in HURDAT as a tropical cyclone. A few ships reported gales over the eastern and northeastern quadrants on the 1st in its periphery due to the strong synoptic scale pressure gradient. However, peak winds directly due to this system were about 30 kt, which is used as the initial intensity. Jun 2: 1. Maps: HWM analyzes a closed low pressure of 1010 mb at 30.0N, 76.0W with a warm frontal boundary to the north at 12Z. Microfilm shows a closed low pressure of at most 1011 mb at 30.5N, 75.0W at 12Z. 2. Ship highlights: 35 kt SE and 1011 mb at 28.2N, 74.5W at 00Z (COADS). 35 kt SE and 1010 mb at 30.7N, 73.3W at 12Z (COADS). 55 kt [likely high bias] ESE and 1015 mb at 31.3N, 72.7W at 12Z (COADS). (Note that a second 50-kt ship report was shown in the microfilm map. However, this appears to be the same ship as COADS, incorrectly plotted one degree too far north.) 40 kt ESE and 1003 mb at 33.6B, 74.6W at 18Z (COADS). 3. Aircraft highlights: Central pressure of 1008 mb near 32.5N, 75.5W at 2130Z (micro). 4. Discussion: MWL: The tropical depression continued toward Hatteras, reaching tropical storm Intensity late the following day when information received from a Navy reconnaissance aircraft and from ship reports near the center of the cyclone indicated winds in excess of 34 kt. This unnamed tropical storm was the first of the season in the North Atlantic region. The highest sustained wind measured in the storm was recorded aboard the ALCOA POLARIS at noon on the 2d near 31N, 73W when 55-kt east-southeasterly winds were encountered. Reanalysis: The system is upgraded to a tropical storm at 00Z, based upon a 35 kt ship observations close to the center. COADS shows two ships at 12Z on the 2nd reporting 55 kt in the northeast quadrant but MWL and microfilm indicate that it was only one ship. Furthermore, comparison with nearby ship data at 12Z on the 2nd show that the 55 kt reported is likely to have a 10- 15 kt high bias. At 2130Z on the 2nd, a reconnaissance aircraft investigated the tropical storm measuring a central pressure of 1008 mb, which has been added to the 00Z time slot of June 3rd. June 3: 1. Maps: HWM analyzes a closed low pressure of 1005 mb at 36.5N, 76.2W with a warm frontal boundary extending to the northeast at 12Z. Microfilm shows a closed low pressure of at most 1005 mb at 36.5N, 76.0W at 12Z. 2. Ship highlights: 40 kt SE and 1009 mb at 33.4N, 73.4W at 00Z (COADS). 40 kt S and 1001 mb at 33.4N, 74.2W at 03Z (MWL). 40 kt SSE and 1015 mb at 33.2N, 71.7W at 05Z (MWL). 40 kt S and 1016 mb at 36.8N, 72.5W at 12Z (COADS). 3. Land highlights: 40 kt ESE and 1006 mb at Diamond Shoals, NC at 06Z (micro). 11 kt SE and 1003 mb at Cape Hatteras, NC at 0659Z (SWO). 20 kt ENE and 1004 mb at NAS Oceana, VA at 1058Z (SWO). 40 kt ENE and 1006 mb at Chesapeake Lightship, VA at 11Z (SWO). 35 kt SSE and 1011 mb at Ocean City, MD at 18Z (micro/SWO). 14 kt ENE and 1005 mb at NAS Patuxent River, MD at 19Z (SWO). 12 kt ENE and 1008 mb at Baltimore, MD at 2156Z (SWO). 34 kt NE at Norfolk, VA (no time given) (CLIMO). 4. Discussion: MWL: The cyclone crossed over the Carolina Outer Banks before noon on the 3d with a central pressure of 1004 mb and continued in a generally northwesterly direction up the Chesapeake Bay while losing intensity. At Norfolk, Virginia a new all time 24-hourly precipitation record was set with 6.87 in. collected after 0650 EST on the 2d. The fastest mile recorded at Norfolk during the storm was 39 mph registered on the 3d. Vessels encountering gale force winds off the southeastern United States coast in this tropical cyclone were mainly concentrated in the northeastern quadrant of the storm in the 5-degree square between latitudes 30 and 35N., longitudes 70 and 75W on the 2d and 3d. They include the ALCOA POLARIS, ASTID ONSTAD, CHARIS, COMAYAGUA, CROWN TRADER, KENDALL FISH, RIVIERA PRIMA, and WORLD CHARITY. MWR: Each year several storms occur which are not entirely tropical in character. Tropical cyclones derive their energy from latent heat of condensation while extratropical cyclones depend upon proper positioning of cold and warm air masses; i.e., cold air sinks and spreads under warm air causing air motion. At times half-breed cyclones develop over tropical oceans and tap both energy sources. In these cases it is difficult to decide whether a tropical cyclone name should be assigned to the Low. The Unnamed Storm in September was of this type, as was the late May-early June storm. Reanalysis: On the 3rd, the tropical storm continued northward and a couple of ships reported gale-force winds, mainly over the northern and eastern quadrant where the pressure-gradient was the strongest. The tropical storm made landfall around 08Z on the 3rd, just west of Cape Hatteras, NC. Cape Hatteras, NC, reported 11 kt SE and 1003 mb at 0659Z on the 3rd, suggesting a central pressure of 1002 mb. However, a few hours earlier at 03Z, a ship reported 40 kt S wind with 1001 mb, which suggests a central pressure of 997 mb. Taking a blend of the two gives 1000 mb, which has been added to the 06Z time slot. A central pressure of 1000 mb suggests maximum surface winds of 42 kt and 47 kt, from the north of 25N Brown et al. and north of 35N Landsea et al. pressure-wind relationships, respectively. Based on a forward speed of about 20 kt, an intensity of 50 kt is analyzed at 06Z on the 3rd and at landfall. 50 kt is also the peak intensity of this tropical cyclone. Diamond Shoals, NC, reported 40 kt E at 06Z on the 3rd. The fast-moving tropical storm reached the coast of North Carolina around 08Z on the 3rd as a 50 kt tropical storm. No gale-force winds were reported in the Outer Banks of North Carolina likely because the radius of maximum winds stayed offshore. However, some tropical storm force winds did occur farther north along the coast and it is analyzed that the strongest winds along the coast were about 40 kt. At 1058Z on the 3rd, Oceana, VA, a coastal station, reported 20 kt ENE and 1004 mb, suggesting a central pressure of 1002 mb, which has been added to the 12Z time slot. Late on the 3rd, the tropical storm moved farther inland and began to weaken. Ocean City, MD, reported 35 kt SSE and 1011 mb at 18Z on the 3rd. Norfolk, VA, reported 34 kt NE but the time is unknown. At 19Z on the 3rd, Patuxent River, MD, an inland station, reported 14 kt ENE and 1005 mb, suggesting a central pressure of 1003 mb, which has been added to the 18Z time slot. At 2156Z on the 3rd, Baltimore, MD, reported 12 kt ENE and 1008 mb, suggesting a central pressure of 1006 mb, which has been added to the 00Z time slot on June 4th. June 4: 1. Maps: HWM analyzes a closed low pressure of 1015 mb at 40.0N, 78.0W with a weakening warm frontal boundary extending to the northeast at 12Z. Microfilm shows a closed low pressure of at most 1014 mb at 40.0N, 78.5W at 12Z. 2. Ship highlights: 9 kt ESE and 1012 mb at Harrisburg, PA at 0559Z (SWO). 10 kt ESE and 1014 mb at Philipsburg, PA at 1151Z (SWO). 3. Discussion: MWL: Late on the 4th it dissipated over eastern Ohio. Reanalysis: On the 4th, the tropical cyclone turned to the northwest and west and gradually lost strength. Weakening to a tropical depression is analyzed at 00Z on the 4th. At 0559Z on the 4th, Harrisburg, PA, reported 9 kt ESE and 1012 mb, suggesting a central pressure of 1010 mb, which has been added to the 06Z time slot. At 1151Z on the 4th, Philipsburg, PA, reported 10 kt ESE and 1014 mb, suggesting a central pressure of 1012 mb, which has been added to the 12Z time slot. Synoptic observations over the Ohio Valley after 12Z on the 4th indicate that the tropical cyclone had weakened to a trough of low pressure. The last position is analyzed at 12Z on the 4th. Sources: the NHC microfilm maps, the Historical Weather Maps series, the COADS ship database, Mariners Weather Log, Surface Weather Observations, and State Climatological Data. This disturbance was in Jack Beven and David Roths List of Suspects. |