**Weekly Report - Snowpack / Drought Monitor Update Date: November 15,
2007**

**SNOTEL SNOWPACK AND PRECIPITATION SUMMARY**

**Snow:** Although very early into this year's snowfall season, the
majority of higher SNOTEL sites over Wyoming (Fig. 1) show the greatest
above normal snow water equivalent values in the West. The remainder of
the West is essentially without snow cover except for the highest peaks
in the Northwestern States.

**Temperature:** During the past seven days, temperatures were up to 10
degrees F above normal across the Central Rockies to near normal over
the Northern Cascades (Fig.2).

**Precipitation:** For the past week, scattered precipitation fell
across the Western States with the exception of Arizona, New Mexico,
Colorado, and east-central Montana where little if any occurred (Fig.
3). For the 2008 Water Year that began on October 1, 2007, precipitation
(rain and snow water equivalent) is above normal over the Intermountain
West (Idaho and Northern Nevada) and over Wyoming's Rockies and Bighorn
Mountain Ranges. Dryness increases the further south one travels across
the West (Fig. 3a).

**WESTERN DROUGHT STATUS**

**The West:**  Light to moderate precipitation spread across much of the
West outside of the arid Southwest and the mountains of Colorado.
Temperatures averaged 4 to 8 degrees or more above normal over the
interior West. With 60-day precipitation well above normal, D3 drought
was eliminated from eastern Idaho. D2 transitioned to D1 in
north-central Idaho. D2 receded in eastern Oregon. The moisture
eliminated the D3 areas in Montana, and D1 improved to D0 in
southwestern Montana. **Author:** [Douglas Le Comte, Climate Prediction
Center, NOAA/NWS](mailto:droughtmonitor@unl.edu)

***A comprehensive narrative describing drought conditions for the
nation can be found at the end of this document.***

# DROUGHT IMPACTS DEFINITIONS ([**http://drought.unl.edu/dm/classify.htm**](http://drought.unl.edu/dm/classify.htm))

The possible impacts associated with **D4 (H, A)** drought include
widespread crop/pasture losses and shortages of water in reservoirs,
streams, and wells creating water emergencies. The possible impacts
associated with **D3 (H, A)** drought include major crop/pasture losses
and widespread water shortages or restrictions. Possible impacts from
**D2 (H, A)** drought are focused on water shortages common and water
restrictions imposed and crop or pasture losses likely. The possible
impacts associated with **D1 (H, A)** drought are focused on water
shortages developing in streams, reservoirs, or wells, and some damage
to crops and pastures (Figs.4, 4a, and 4b).

**SOIL MOISTURE**

Soil moisture (Fig.5), is simulated by the [VIC macroscale hydrologic
model](http://www.hydro.washington.edu/Lettenmaier/Models/VIC/VIChome.html).
The detailed, physically-based VIC model is driven by observed daily
precipitation and temperature maxima and minima from approximately 2130
stations, selected for reporting reliably in real-time and for having
records of longer than 45 years (and various other criteria).

## 

## 

## OBSERVED FIRE DANGER CLASS

The National Interagency Coordination Center provides a variety of
products that describe the current wildfire status for the U.S. -
<http://www.nifc.gov/information.html>. The latest Observed Fire Danger
Class is shown in Figs. 6and 6a shows the current active wildfires
across the West - <http://geomac.usgs.gov/>.

## U.S. HISTORICAL STREAMFLOW

## This map, (Fig. 7) shows the 7-day average streamflow conditions in hydrologic units of the United States and Puerto Rico for the day of year. The colors represent 7-day average streamflow percentiles based on historical streamflow for the day of the year. Thus, the map shows conditions adjusted for this time of the year. Only stations having at least 30 years of record are used. Sub-regions shaded gray indicate that insufficient data were available to compute a reliable 7-day average streamflow value. During winter months, this situation frequently arises due to ice effects. The data used to produce this map are provisional and have not been reviewed or edited. They may be subject to significant change.

## **<http://water.usgs.gov/cgi-bin/waterwatch?state=us&map_type=dryw&web_type=map>.**

**VEGETATION HEALTH**

The images (Fig. 8) are color-coded maps of vegetation condition
(health) estimated by the Vegetation and Temperature Condition Index
(VT). The VT is a numerical index, which changes from 0 to 100
characterizing change in vegetation conditions from extremely poor (0)
to excellent (100). Fair conditions are coded by green color (50), which
changes to brown and red when conditions deteriorate and to blue when
they improve.

<http://www.orbit.nesdis.noaa.gov/smcd/emb/vci/usa.html>.

# STATE ACTIVITIES

State government drought activities can be tracked at the following URL:
<http://drought.unl.edu/mitigate/mitigate.htm>. NRCS SS/WSF State Office
personnel are participating in state drought committee meetings and
providing the committees and media with appropriate SS/WSF information -
<http://www.wcc.nrcs.usda.gov/cgibin/bor.pl>. Additional information
describing the products available from the Drought Monitor can be found
at the following URL: <http://drought.unl.edu/dm/>

## 

## FOR MORE INFORMATION

The National Water and Climate Center Homepage provide the latest
available snowpack and water supply information. Please visit us at
[http://www.wcc.nrcs.usda.gov](http://www.wcc.nrcs.usda.gov/). This
document is available from the following location on the NWCC homepage -
<http://www.wcc.nrcs.usda.gov/water/drought/wdr.pl>

[This report](http://www.wcc.nrcs.usda.gov/water/drought/wdr.pl) uses
data and products provided by the Interagency Drought Monitor Consortium
members and the National Interagency Fire Center.

/s/ NOLLER HERBERT

Director, Conservation Engineering Division

> ![](media/image1.png){width="6.106944444444444in"
> height="8.281944444444445in"}

**Fig 1. Very early season snow water equivalent percent of normal for
the 2008 Water Year that began on October 1, 2007. Ref:
<ftp://ftp.wcc.nrcs.usda.gov/data/water/wcs/gis/maps/WestwideSWEPercent.pdf>**

![](media/image2.png){width="6.790277777777778in"
height="8.646527777777777in"}

![](media/image3.png){width="7.602777777777778in"
height="5.867361111111111in"}

![](media/image4.png){width="6.447916666666667in"
height="8.641666666666667in"}

![](media/image5.png){width="7.399305555555555in"
height="5.518055555555556in"}

![](media/image6.png){width="7.204166666666667in"
height="5.511111111111111in"}

**Fig. 4b. Drought Monitor for Tennessee and the Southeastern States
with statistics over various time periods shows some of the severest
drought conditions in the US. Note some worsening over the Southeast
during the past week.**

![](media/image7.png){width="5.242361111111111in"
height="3.928472222222222in"}![](media/image8.png){width="5.354861111111111in"
height="4.085416666666666in"}

![](media/image9.png){width="5.746527777777778in"
height="8.190972222222221in"}

![](media/image10.png){width="7.274305555555555in"
height="5.404166666666667in"}

![](media/image11.png){width="7.652083333333334in"
height="4.764583333333333in"}

![](media/image12.png){width="7.1819444444444445in"
height="5.580555555555556in"}

### Fig. 7. This week's map shows somewhat lower stream flows over much of the western slope of the Rockies but severe to extreme conditions over portions of the Southeastern and Mid-Atlantic States. Ref: USGS <http://water.usgs.gov/waterwatch/?m=dryw&w=map&r=us> 

![](media/image13.png){width="5.228472222222222in"
height="6.228472222222222in"}

**Fig. 8: This remote satellite AVHRR map shows stressed vegetation as
compared to last year. Recent precipitation has helped to green-up areas
of Southeast but the underlying drought remains firmly entrenched. Note:
Plants in the northern regions tend to show die-off as first freeze
occurs. Ref:
<http://www.orbit.nesdis.noaa.gov/smcd/emb/vci/usa.html>).**

**National Drought Summary \-- November 13, 2007**

*The discussion in the Looking Ahead section is simply a description of
what the official national guidance from the National Weather Service
(NWS) National Centers for Environmental Prediction is depicting for
current areas of dryness and drought. The NWS forecast products utilized
include the HPC 5-day QPF and 5-day Mean Temperature progs, the 6-10 Day
Outlooks of Temperature and Precipitation Probability, and the 8-14 Day
Outlooks of Temperature and Precipitation Probability, valid as of late
Wednesday afternoon of the USDM release week. The NWS forecast web page
used for this section is:*
<http://www.cpc.ncep.noaa.gov/products/forecasts/>*.*

**The Southeast, Mid-Atlantic, Ohio and lower Missouri valleys:** This
was a mostly dry week over the D4 (Exceptional) drought areas in the
Southeast. In fact, Alabama, Georgia, and South Carolina have been
virtually rainless so far this month. With temperatures below normal in
the Southeast, and little evaporation, the lack of rain did not have a
major impact on the drought, but drought intensity did expand by about
one category over southern parts of Alabama and Georgia due to dropping
stream flows. In addition, the D4 area increased in western South
Carolina, and the D2/D3/D4 areas expanded slightly in North Carolina.
Nearly 60 percent of the streams in Georgia reported record lows for
this time of the year on November 13. More than one-half of the streams
in South Carolina measured record lows, as did more than one-third in
Alabama. In North Carolina, 283 water systems are under restrictions -
nearly 80% of the state population, the most since record-keeping began.
Due to low streamflows, D1 drought expanded into central Virginia. D0
and D1 also edged westward in Mississippi.  

**The Northeast:** Over one-half inch rain fell in southern New England
and western Pennsylvania, but this was not enough to significantly
affect the dry areas, although the moisture reduced some of the western
flank of the D0 area in Pennsylvania. D1 drought lingered in southern
New England.

**The Plains:** Short-term dryness resulted in southward expansion of D2
drought in western North Dakota. Continued dryness also led to some
expansion of D2 and D1 in the Nebraska Panhandle and D0 in eastern
Colorado, northwest Kansas, and southwest Nebraska. With many locations
reporting less than 25 percent of normal rainfall during the past 60
days, D0 dryness expanded into southern and central parts of Texas. Soil
moisture is a concern with the winter wheat crop there. Southeast of the
Panhandle, for example, the Northern Low Plains area reported topsoil
moisture at 62 percent very short. Temperatures in the High Plains
averaged 4 to 8 degrees or more above normal for the week.

**The West:**  Light to moderate precipitation spread across much of the
West outside of the arid Southwest and the mountains of Colorado.
Temperatures averaged 4 to 8 degrees or more above normal over the
interior West. With 60-day precipitation well above normal, D3 drought
was eliminated from eastern Idaho. D2 transitioned to D1 in
north-central Idaho. D2 receded in eastern Oregon. The moisture
eliminated the D3 areas in Montana, and D1 improved to D0 in
southwestern Montana.

**Alaska, Hawaii, and Puerto Rico:** Drier weather took hold over most
of Hawaii following the heavy rains of the prior week, but moderate
rains over the Big Island contributed to the D1 drought pulling back to
northern parts of the island. A reassessment shows that a sliver of D1
remains over east Oahu due to ongoing mandatory restrictions for users
of irrigation water from the Waimanalo system.

***Looking Ahead:  ***Weather that could affect dry or drought areas
over the next 2 weeks includes: 1) ongoing rains from a frontal system
tracking eastward through the East, resulting in 0.5 to 1 inch of rain
during November 14-16 from northern parts of Alabama and Georgia through
Tennessee and Kentucky and Virginia. More than 1 inch is forecast from
Pennsylvania to New England. 2) Over 1 inch of rain during November
14-19 in Idaho and western Montana, with slightly lower totals in
eastern Oregon and central Montana. 3) Abnormally dry, warm weather over
the Southwest and Colorado during November 14-19, but above-normal
precipitation forecast for the Rockies and central states during
November 20-24 and for the Great Plains to the Ohio and Tennessee
valleys for November 22-28. 

**Author:** [Douglas Le Comte, Climate Prediction Center,
NOAA/NWS](mailto:droughtmonitor@unl.edu)

  **Dryness Categories**

D0 \... Abnormally Dry \... used for areas showing dryness but not yet
in drought, or for areas recovering from drought.\
\
**Drought Intensity Categories**\
D1 \... Moderate Drought\
D2 \... Severe Drought\
D3 \... Extreme Drought\
D4 \... Exceptional Drought\
\
**Drought or Dryness Types**\
A \... Agricultural\
H \... Hydrological

 

Updated November 14, 2007