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Snow for the Southwest Mountains and Northern Plains to Northeast Sunday; More Significant Storm to Impact Eastern States Next Week

A storm crossing the Southwest states will bring heavy mountain snow Sunday into Monday. Further east, a separate storm will track from the Central Plains to the Mid-Atlantic states bringing a swath of ice and snow along and north of it's storm track Sunday into Monday. Next week, a stronger storm is expected to produce heavy rain over the Southeast with snow and ice from the Midwest to Northeast. Read More >

 

...Tropical Wave Brought New Climate Records...

Synopsis  

The first strong tropical wave of the 2013 Atlantic Hurricane Season to affect Puerto Rico and the US Virgin Islands brought heavy rainfall and cool temperatures to the region. While widespread rainfall totals of 3 to 5 inches were observed across the eastern half of Puerto Rico during July 18th 2013, the highest rainfall amounts were noted across the San Juan Metro Area with totals in excess of 9 inches. 

Daily Data

New Records

Location Record Type Date/Year New Record Previous Record Date/Year
Luis Muñoz Marín Intl Airport 24 hr maximum rainfall July 18th, 2013 9.23" 2.17" 1969
San Juan Metro Area 24 hr maximum rainfall July 18th, 2013 9.23" 3.19" 1950
Luis Muñoz Marín Intl Airport Wettest day on record for any given day July 18th, 2013 9.23" 8.84" September 18th, 1989 (Hurricane Hugo)
San Juan Metro Area 2nd wettest day on record for any given day July 18th, 2013 9.23" 9.67" August 15th, 1944
Luis Muñoz Marín Intl Airport Lowest maximum temperature July 18th, 2013 82ºF 83ºF 1995
San Juan Metro Area Lowest maximum temperature (tied) July 18th, 2013 82ºF 82ºF

1950

Table A- New Records for July 18th

24hr Precipitation Frequency based on San Juan Intl Airport

Average recurrence(years) Precipitation frequency estimates with 90%   confidence intervals (in inches)
1
3.27     (2.91‑3.68)
5
5.66     (5.04‑6.39)
10
6.77     (6.00‑7.62)
25
8.30     (7.35‑9.36)
50
9.50     (8.38‑10.7)
100
10.8     (9.45‑12.2)
200
12.0     (10.5‑13.7)
500
13.8     (12.0‑15.8)
1000
15.2     (13.2‑17.6)

 Table B- 24hr Precipitation Frequency at the Luis Muñoz Marín Intl Airport

For additional info visit PR precipitation frequency webpage: https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_pr.html

Hourly Data

Hourly Observations at the Luis Muñoz Marín Intl Airport for July 18th, 2013

Observation  (Local Time) Rainfall Accumulation (inches)
07:59 AM T
08:59 AM T
09:59 AM 0.53"
10:59 AM T
11:59 AM 1.41"
12:59 PM 2.89"
01:59 PM 1.39"
02:59 PM 1.88"
03:59 PM 0.02"
04:59 PM  0.67"
05:59 PM 0.05"
06:59 PM 0.04"
07:59 PM 0.03"

Table C- Rainfall accumulation per hour at the Luis Muñoz Marín Intl Airport between 8 AM thru 8 PM.

Precipitation Frequency based on San Juan Intl Airport for 1, 2, 3 and 6 hrs.

Average recurrence(years) Precipitation frequency for 1hr  with 90%     confidence intervals (in inches) Precipitation frequency for 2hr with 90%  confidence intervals (in inches) Precipitation frequency for 3hr with 90% confidence intervals (in inches) Precipitation frequency for 6hr with 90% confidence intervals (in inches)
1 1.55  (1.43‑1.69) 1.86  (1.71‑2.03) 2.00  (1.82‑2.20) 2.48  (2.21‑2.78
5 2.15 (1.98‑2.33) 2.70  (2.47‑2.92) 2.95  (2.69‑3.22) 3.89  (3.48‑4.34)
10 2.31 (2.12‑2.51) 2.95  (2.69‑3.17) 3.26  (2.96‑3.55) 4.42  (3.94‑4.94)
25 2.51  (2.30‑2.73) 3.25  (2.96‑3.50) 3.62  (3.29‑3.96) 5.09  (4.47‑5.71)
50 2.65  (2.42‑2.89) 3.45  (3.13‑3.75) 3.89  (3.51‑4.29) 5.58  (4.86‑6.31)
100 2.76  (2.51‑3.04) 3.65  (3.29‑4.00) 4.14  (3.70‑4.60) 6.06  (5.23‑6.93)
200 2.87  (2.61‑3.19) 3.83  (3.43‑4.25) 4.38  (3.88‑4.93) 6.54  (5.57‑7.56)
500 3.01  (2.69‑3.37) 4.06  (3.59‑4.56) 4.69  (4.10‑5.34) 7.18  (5.99‑8.40)
1000 3.10  (2.77‑3.50) 4.23  (3.69‑4.79) 4.91  (4.25‑5.67) 7.64  (6.33‑9.05)

Table D- 1,2,3 and 6hr Precipitation Frequency at the Luis Muñoz Marín Intl Airport

For additional info visit PR precipitation frequency webpage: https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_pr.html

Additional Statistics

July 2013 ended as the wettest July on record at the San Juan Metro Area 

Precipitation Totals Year
14.18" 2013
11.23" 1950
11.08" 2011
10.98" 1901
10.97" 1952

2013 currently ranks as the third wettest start to a year at the San Juan Metro Area

Precipitation Totals Year
53.51" 1902
50.62" 1927
50.00" 2013
48.95" 2010
44.80" 1931

*data til 07/31

 NOTE: Records for the airport date back to January 1st, 1956, National Weather Service statistics for the San Juan Metro Area date back to 1898. Prior to 1956, the official San Juan weather observation station moved between multiple locations in Old San Juan and the Isla Grande Airport (click here for a complete history of the NWS in San Juan).

Click here to return to unique local climate data web page for the NWS San Juan

 Prepared by: Odalys Martinez & Jose Alamo