**P2.42**

**A BLENDED TOTAL WATER VAPOR PRODUCT FOR THE ANALYSIS AND FORECAST OF
WEATHER HAZARDS**

Sheldon J. Kusselson \*

NOAA/NESDIS, Satellite Services Division, Camp Springs, Maryland

Stanley Q. Kidder and John M. Forsythe

CIRA/Colorado State University, Fort. Collins, Colorado

**1. INTRODUCTION**

For over 25 years the Satellite Analysis Branch (SAB) Precipitation Team
of NOAA's Satellite and Information Service (NESDIS) has provided highly
detailed operational satellite analyses and precipitation estimates to
NOAA/NWS Weather Forecast Offices (WFOs), River Forecast Centers (RFCs)
and the National Center for Environment- al Prediction Center (NCEP)
Hydrometeorological Prediction Center (HPC) for storms that are
currently or expected to produce heavy precipitation resulting in loss
of life or property to the nation. Until the early 1990's, the only
operational satellite data used on a regular basis was the geostationary
infrared (IR), visible (VIS) and water vapor (WV) channels. Since 1991,
SAB has acquired additional satellite imagery tools and worked closely
with governmental and academic researchers, to stay on the cutting edge
of improved satellite precipitation analysis and applications to further
improve support to NOAA's NWS offices from Guam to Puerto Rico (Ferraro,
et.al, 1998). The SAB Precipitation Team is also a test-bed for
improving current and future satellite data and applications so that
forecasters can improve their ability to analyze heavy precipitation,
recognize computer model deficiencies and respond more quickly to
potential flash flood threats with longer forecast warning lead times.
This paper will present current operational and future blended Total
Precipitable Water (TPW) products; real operational examples of the
future products as proof of concept.

**2. CURRENT AND FUTURE TPW PRODUCTS**

NOAA/NESDIS has generated global composited single sensor
multi-satellite DMSP SSM/I (figure 1***a***) and NOAA AMSU (figure
1***c***) TPW products

for use by forecasters since 1991 (Kusselson, 1993) and 2000,
respectively. In the last few years an effort has been made by CIRA/
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

\* *Corresponding author address:* Sheldon J. Kusselson,
NOAA/NESDIS/OSDPD/SSD/SAB, Room 401, WWB, 5200 Auth Road, Camp Springs,
MD 20746; e-mail: [Sheldon.Kusselson@noaa.gov]{.underline}

Colorado State University researchers to blend the DMSP SSM/I and NOAA
AMSU polar-orbiting microwave satellites' TPW over water (Kidder and
Jones, 2007) and GPS-MET remote sensing TPW values

( <http://www.suominet.ucar.edu/index.html> ) over the CONUS. Figures 1
***a-c*** show the operational remote sensing data that went into
producing the experimental blended SSM/I - AMSU - CONUS GPS-MET TPW
product (***d**)*.

![](media/image1.png){width="0.7417322834645669in"
height="0.6984251968503937in"}![](media/image2.png){width="0.7417322834645669in"
height="0.6984251968503937in"}![](media/image3.png){width="0.15196850393700786in"
height="2.6251968503937007in"}![](media/image4.png){width="2.4153543307086616in"
height="1.6251968503937009in"}![](media/image4.png){width="0.8133858267716535in"
height="0.6984251968503937in"}![](media/image5.png){width="6.10236220472441e-2in"
height="5.15748031496063e-2in"}![](media/image6.jpeg){width="7.204724409448819e-2in"
height="5.551181102362205e-2in"}![](media/image6.jpeg){width="7.165354330708662e-2in"
height="5.551181102362205e-2in"}![](media/image7.png){width="0.11929133858267717in"
height="8.346456692913386e-2in"}![](media/image6.jpeg){width="7.165354330708662e-2in"
height="5.62992125984252e-2in"}

Fig. 1. ***a)*** DMSP SSM/I single sensor two satellite TPW composite;
***b)*** GPS-MET TPW over the CONUS; ***c)*** NOAA AMSU single sensor
three satellite TPW composite = ***d)*** Blended DMSP SSM/I, GPS-MET,
NOAA AMSU TPW product.

With more frequent updates, less data gaps, the elimination of biases
between the data and superior analysis overland, the greatest benefit of
using a future operationally supported multi-remote sensing blended TPW
product will be that analysis time will be significantly reduced at
forecast and warning sites and probably help contribute to further
improvements in the warning lead time and forecast accuracy of hazardous
weather.

A complimentary experimental blended TPW anomaly product, figure 2 as an
example, is also being produced that takes the current blended TPW
product and compares it with a 1988-1999

climatology of SSM/I TPW over the ocean and a mix of radiosonde/TOVS
soundings overland (conversation/e-mail with co-author and research
meteorologist John Forsythe of CIRA/Colorado State University, 2006).

![](media/image8.png){width="2.625in" height="1.25in"}

Fig. 2. Experimental blended DMSP SSM/I - GPS-MET - NOAA AMSU TPW
anomaly product for 1200 UTC October 6, 2006 with various aqua and
yellow color shades representing above normal and brown representing
below normal.

This has already been very helpful to forecasters in giving a
climatological (above or below normal) perspective to the current
blended TPWs. The current experimental blended TPW and anomaly products
cover most of the western hemisphere and recently GOES sounder imagery
was being used over the CONUS in places where GPS-MET coverage is not
adequate. These products are being produced by CIRA/Colorado State
University and distributed on the internet at:
<http://amsu.cira.colostate.edu/gpstpw> . A separately produced global
blended TPW only over the oceans using SSM/I and AMSU data can be found
at: <http://amsu.cira.colostate.edu/TPW> .

A blended TPW and anomaly product as shown in figures 1***d*** and 2,
respectively, are expected to become operational around 2010. It is
hoped that additional TPW data sets, like those shown below in figure 3,
will be included.

![](media/image10.png){width="0.8181102362204724in"
height="0.658267716535433in"}![](media/image11.png){width="0.4582677165354331in"
height="0.658267716535433in"}![](media/image12.png){width="0.9854330708661417in"
height="2.283464566929134e-2in"}![](media/image13.png){width="0.8937007874015748in"
height="0.658267716535433in"}![](media/image14.png){width="0.9854330708661417in"
height="0.6251968503937008in"}![](media/image14.png){width="0.9854330708661417in"
height="2.283464566929134e-2in"}![](media/image14.png){width="0.8937007874015748in"
height="2.283464566929134e-2in"}![](media/image15.jpeg){width="0.8582677165354331in"
height="0.6251968503937008in"}![](media/image16.gif){width="4.566929133858268e-2in"
height="4.566929133858268e-2in"}![](media/image6.jpeg){width="4.566929133858268e-2in"
height="4.566929133858268e-2in"}![](media/image16.gif){width="4.566929133858268e-2in"
height="4.566929133858268e-2in"}![](media/image6.jpeg){width="4.566929133858268e-2in"
height="4.566929133858268e-2in"}![](media/image6.jpeg){width="4.566929133858268e-2in"
height="4.566929133858268e-2in"}![](media/image17.png){width="0.8751968503937008in"
height="0.6200787401574803in"}![](media/image6.jpeg){width="8.976377952755905e-2in"
height="7.086614173228346e-2in"}

Fig. 3. TPW data/imagery generated from current and future remote
sensing that could be included in a future operational global blended
TPW product.

**3. OPERATIONAL EXAMPLE OF THE USE**

**OF FUTURE TPW PRODUCTS FOR HEAVY PRECIPITATION FORECASTING**

During the later half of June 2006, the experimental blended TPW and
anomaly products were used operationally by NESDIS analysts to help
forecasters on the East Coast of the United States identify conditions
that could result in heavy precipitation and subsequent flooding. Since
most of the precipitable water in the atmosphere exists from the surface
to 3km (Kusselson, 1993), TPW has been useful for locating
concentrations of high low-level moisture (sometimes referred to as the
"TPW plume" or "Atmospheric River"). This TPW plume is one of the most
recognizable satellite signatures of potential heavy rainfall that can
lead to flash flooding.

![](media/image19.png){width="0.17152777777777778in"
height="1.5in"}![](media/image20.png){width="1.1429133858267717in"
height="1.5in"}![](media/image21.png){width="1.213779527559055in"
height="1.5in"}![](media/image22.png){width="0.19094488188976377in"
height="1.5in"}

Fig. 4. Experimental Blended TPW on left and complimentary Blended TPW
anomaly product on the right from the morning of June 25, 2006.

The left panel of figure 4 shows the experimental blended TPW product
and the black oval highlights the low level moisture plume that extended
from the western Atlantic Ocean to the mid-Atlantic region of the
eastern United States. At the same time on the right panel of figure 4,
the blended TPW anomaly product showed a persistently high anomaly (near
200 percent of normal) that was centered over the mid-Atlantic region.
This helped NOAA/NESDIS Satellite Analysis Branch (SAB) analysts focus
on this area for potential heavy rain generation and flash flooding and
alert NOAA/NWS forecasters of their concerns. And the heavy rain
developed and subsequent flooding occurred during the following 24-48
hours. The results in figure 5 on the left column of the next page were
an area of 200 - 400 mm of rain (left panel) that fell through June 27;
flooding of a major highway (middle panel) in the Maryland suburbs of
the Washington, D.C. metropolitan area that resulted in at least one
drowning and major problems for rush hour commuters; lead author's
observed rainfall (to the right of middle picture) at his home in
Montgomery County, Maryland. This case serves as a strong proxy to
continuing further research in producing reliable polar-orbiting
microwave TPW data overland to supplement the GPS-MET and GOES sounder
data.

![](media/image23.png){width="0.7846456692913386in"
height="1.25in"}![](media/image24.jpeg){width="1.051968503937008in"
height="1.25in"}

Fig. 5. Storm rainfall through 13 UTC Jun 27, 2006 on left; highway
flooding in Maryland suburbs of Washington, D.C., in the middle panel;
the author's rainfall amounts from Silver Spring, Montgomery County,
Maryland (far right).

**4. FUTURE BLENDED TPW PRODUCTS FOR SEVERE STORM FORECASTING**

No single meteorological parameter provides all the information to the
forecaster to predict the actual location and time of development of
severe weather. Geostationary satellites, in the past decade or so, have
given forecasters moisture and temperature soundings and generated
parameters like TPW, LI, CAPE, CINH, etc., in clear to partly cloudy
areas. These observations, when used with conventional observational
data and numerical model output have helped forecasters key in on areas
of potential severe weather (Lashley, 2003). Once severe weather
develops, infrared and visible imagery have played the traditional
observational role in helping forecasters follow the continued
development and movement of these convective/severe elements. Moisture
is one of the many key ingredients to severe weather generation and can
also be looked at to supplement and compliment other key parameters. The
experimental blended TPW and anomaly products serve to show one of those
key parameters, total atmospheric moisture. Overland, the product
(described earlier) mostly uses the GPS-MET network. One of the
advantages of using GPS-MET over GOES soundings is the ability to get
TPW information in cloudy and rainy areas. In the future with the
addition of microwave retrievals overland, the product should be further
improved. Satellite analysts in NOAA/NESDIS SAB have developed
subjective satellite signatures that can be used in conjunction with
other parameters to help locate favorable areas of potential severe
storm development and intensification. An example of a use of the
blended TPW and anomaly products to help enhance severe weather
forecasting is seen in figure 6 with a case from March 28, 2007. Here,
the experimental blended TPW (top) and blended TPW anomaly (bottom)
products, described earlier in this paper, could be used for this day's
severe weather events that occurred in an area from western Texas to
South Dakota. Below in figure 6, the top panel of blended TPW shows the
trends in total moisture from 18 UTC March 28 to 06 UTC March 29.
Development of severe storms is helped by deep moisture interacting with
dry air (Konop, 2006). A signature of the moisture gradient (white oval)
can be a good first guess of potential severe storms. In addition, the
bottom panel (figure 6 below) of TPW anomaly showed that the gradient
area (**red** **oval**) between the maximum below normal TPW to the west
and well above normal TPW to the east can also be considered a good
first guess for the to potential severe weather that was to develop
during the afternoon of March 28 and continue into the evening.

![](media/image25.png){width="0.7854330708661418in"
height="0.9763779527559056in"}![](media/image26.png){width="0.7299212598425197in"
height="0.9763779527559056in"}![](media/image27.png){width="0.7854330708661418in"
height="0.9763779527559056in"}![](media/image28.png){width="0.22440944881889763in"
height="1.1015748031496062in"}![](media/image29.png){width="0.7854330708661418in"
height="1.1220472440944882in"}![](media/image30.png){width="0.16023622047244093in"
height="1.1779527559055119in"}![](media/image31.png){width="0.7299212598425197in"
height="1.1220472440944882in"}![](media/image32.png){width="0.7854330708661418in"
height="1.1220472440944882in"}

Fig. 6. Top Panels - Blended TPW product for 18 UTC March 28 and 00 and
06 UTC March 29, 2007; Bottom panels - Blended TPW anomaly product for
the same times.

![](media/image33.jpeg){width="1.6in"
height="1.3751968503937009in"}![](media/image34.png){width="0.85in"
height="1.05in"}![](media/image34.png){width="0.15in" height="0.15in"}

Fig. 7. Left panel - Severe weather reports for the 24 hour period
ending 05 UTC March 29, 2007 (midnight CDT March 28); Right panel -
picture of southern Texas panhandle tornado (located with a **red**
cross (**+)** in figure 6) around 23 UTC (6PM CDT) on March 28.

Figure 7 (left panel), on the preceding page showing the location of
severe weather reports, should be compared with the blended TPW and
anomaly products in figure 6. The location of the tornado in Silverton,
Texas (right panel), one of the many spawned on March 28, can be found
in the figure 6 panels with a red cross (**+** ).

**5. SUMMARY AND FUTURE**

Global composited remote sensing derived TPW products are tools that are
helping NOAA scientists better analyse and forecast weather hazards.
These products continue to evolve and develop with the help of a unique
collaboration between the research and forecasting communities. Shown in
this paper was the evolving of an experimental blended TPW product and
companion TPW anomaly product with a heavy precipitation/flash flood and
a severe weather case study example. Future improvements include
microwave retrievals overland, the addition of more satellites, more
frequent updates of the products. By the time the products are
operational in 2010, it is anticipated that familiarity and applications
of these products will progress further, so that forecasters will be
able to use the imagery more efficiently with other data sets resulting
in improved forecast locations and lead times for hazardous weather
events.

**6. REFERENCES**

Ferraro, R.R, S.J. Kusselson and M. Colton, 1998: An introduction to
passive microwave sensing and its applications to meteorological
analysis and forecasting. National Weather Digest, Vol. 22, Num 3, pages
11-23.

Kidder, S.Q. and A.S. Jones, 2007: A blended satellite Total
Precipitable Water product for operational forecasting. *Journal of
Atmospheric and Oceanic Tech.*, 20 pages. html version at:
<http://amsu.cira.colostate.edu/kidder/Blended_TPW.pdf>

Konop, E., 2006: April 7, 2006 Tornado outbreak across the Tennessee
Valley. University of Wisconsin Atmospheric and Ocean Sciences Journal,
Vol. 1. html version at:

<http://www.aos.wisc.edu/uwaosjournal/Volume1/AOS453/FCS_Konop.pdf>

Kusselson, S.J., 1993: The operational use of passive microwave data to
enhance precipitation forecasts. *13^th^ Conference on Weather Analysis
and Forecasting*, Vienna, Virginia, AMS 434-438.

Lashley, S.L., 2003: Using GOES satellite products to enhance National
Weather Service warning operations. 12^th^ Conference on Satellite
Meteorology and Oceanography and 3^rd^ Conference on Artificial
Intelligence Applications to Environmental Science. Html version at:
<http://ams.confex.com/ams/pdfpapers/51994.pdf>

Paper URL address:

<ftp://gp16.ssd.nesdis.noaa.gov/pub/Publications/AMS_22nd_WAF_extended_abstract_June_2007.doc>

Poster URL address:

<ftp://gp16.ssd.nesdis.noaa.gov/pub/Presentations/Conferences/AMS_22nd_WAF.ppt>