Puerto Rico was lucky that Jeanne didn't increase to hurricane strengh when it made landfall at SE Puerto Rico although some unofficial gusts were reported arounf hurricane force.
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Hydrologic Summary for Puerto Rico and the U.S. Virgin Islands
What was to become Tropical Storm Jeanne developed very rapidly out a tropical depression located to the east of the Leeward Islands on the 13th September 2004. Jeanne became a named system on the 14th as the center tracked south of the U.S. Virgin Islands. A Flood Watch for Flash Flooding was issued during the early evening of the 14th as the outer rain bands from the storm began to affect these areas. The storm tracked south of Vieques early on the 15th and then entered the southeast coast of Puerto Rico and basically traversed the island during the day, skirting the northwest coast before exiting about 00Z on the 16th. The hydrologic impact of Jeanne was widespread, with numerous streams and rivers flooded. Flash Flood Warnings were initially issued for the U.S. Virgin Islands, Vieques and Culebra very early on the 15th and extended over the course of the day to cover every municipality in Puerto Rico. These warnings reissued throughout the day and into the 16th, resulted in over 300 Flash Flood Warnings issued on the 15th and over 150 on the 16th. River Flood Warnings were issued for the Rio Cibuco, Rio de la Plata and Rio Guanajibo on the 16th. Some of the more serious impacts were reported from Vieques, where 23.75” of rain fell over several days. Reports of damage to streets, collapsed bridges and landslides were received from the island. In the U.S. Virgin Islands there were similar reports of damage. Evacuations of up to 400 people were reported along parts of the Rio Grande de Anasco on the island of Puerto Rico and there were numerous road closures due to flooding and mudslides throughout the island. One flood related fatality was reported from the Moca area, where a 45-year old man was drowned in a tributary stream of the Rio Culebrinas. A table of rainfall data from the top 25 rainfall amounts during the three days of Jeanne’s most direct effects is shown below:
Table 1. Twenty-four hour rainfall ending at 1200 UTC for the three days associated with Tropical Storm Jeanne.
Station (NWS ID)
Sep 15
Sep 16
Sep 17
3-Day total
Vieques – Camp Garcia (WVEP4)
2.20
14.75
6.78
23.75
Aibonito 1S (ALPP4)
1.17
15.00
2.50
18.67
Rio Icacos nr Naguabo (NGIP4)
2.67
13.81
1.96
18.44
Rio Mameyes nr Sabana (MSAP4)
1.91
13.92
1.26
17.09
Lago De Matrullas - Orocovis (OROP4)
0.28
9.54
5.46
15.28
Rio Matrullas Alert gage (ZDDP4)
0.47
7.68
7.05
15.20
Queb. Blanca nr San Lorenzo (SLGP4)
1.60
10.78
2.46
14.84
Jayuya RG nr Bo. Saliente (JAZP4)
0.29
9.78
4.73
14.80
Corozal Alert gage (ZDBP4)
1.14
8.86
4.25
14.25
Rio Turabo abv Borinquen (CAKP4)
2.09
10.21
1.92
14.22
Rio Coamo at Hwy 14 (COAP4)
0.31
8.36
5.14
13.81
Queb. Salvatierra nr San Lorenzo (SLJP4)
1.48
10.78
2.46
13.19
Pueblito del Rio RG nr Gurabo (GUSP4)
1.60
10.83
0.55
12.98
Charlotte Amalie, St. Thom. USVI (XTCP4)
1.79
9.25
1.73
12.77
Barrio Beatriz RG nr Caguas (BZDP4)
0.70
10.94
0.76
12.40
Quebrada Arenas (SLLP4)
2.16
7.99
2.22
12.37
Turpentine Run, St. Thom. USVI (XTFP4)
1.86
8.50
1.73
12.09
Rio Mameyes at Mameyes (MSEP4)
1.08
9.97
0.98
12.03
Rio Fajardo at Hwy 976 (FAJP4)
1.44
9.26
1.30
12.00
Rio De La Plata nr Naranjito (ZEEP4)
2.13
8.39
1.39
11.90
Rio Blanco nr Florida (NGKP4)
1.73
8.01
2.01
11.75
Rio Espiritu Santo nr Rio Grande (VEDP4)
1.12
9.66
0.89
11.67
Rio Canovanas nr Campo Rico (CNAP4)
0.77
9.31
1.47
11.55
Rio De Bayamon at Arenas (CIFP4)
0.66
10.13
0.72
11.51
Lago De Cidra (DRAP4)
1.48
9.44
0.35
11.28
Bisley Meteorological Stn. (MSCP4)
1.02
9.15
0.83
11.00
According to the Weather Bureau Technical Paper No. 42 (1961) 24-hour rainfall of such magnitude corresponds to anywhere from a 5-year to in excess of a 100-year return period, depending very much on specific locations. The highest return frequency was at Aibonito, where the 24-hour rainfall of 15.00” corresponded to more than a 100-year event. The 14.75” at Vieques was close to a 100-year event, while at Charlotte Amalie, the maximum 24-hour rainfall of 9.25 inches was around a 25-year event. The nearly 10 inches at Rio Mameyes however, was closer to a 10-year event. The flooding produced by these rains was widespread, although not particularly severe in most areas. A total of 54 locations (including 11 of the 13 NWS forecast locations) exceeded Flood Stage at some time during the event, covering nearly the entire island. A slight majority (27) reached the NWS-defined Moderate Flood Stage, 23 reached only Minor Flood Stage and only 4 achieved Major Flood Stage. The most serious flooding appears to have occurred in the lower portions of Rio Grande de Manati and in the Rio de la Plata and Rio Culebrinas basins. No river gage stations in Puerto Rico established a new flood of record, and crests from this storm were in most cases considerably lower than during Hurricane Georges in 1998 or Hurricane Hortense in 1996. One station in the U.S. Virgin Islands, Turpentine Run at Mt. Zion (XTFP4), set a new record of 8.65 feet, which broke the previous record of 7.28 feet set in 1995. It is important to note that records at this site only extend back 10 years.



