Multiple Atmospheric Rivers Impact California in Early 2017

The state of California has been suffering from a multi-year drought that has severely depleted water resources and reservoir levels. Recent winters have failed to produce precipitation and mountain snows to replenish the losses during the dry summers. However, the situation has rapidly changed this winter, particularly in the past week when multiple atmospheric rivers have impacted the state.

An atmospheric river is a concentrated channel of deep moisture that is transported from the tropical Pacific Oceanic regions to the West Coast of the United States.  These events are often associated with prodigious amounts of rainfall and mountain snows that lead to flooding, mudslides, and avalanches.  We have seen such events this past week impact California, especially the central and northern parts of the state.  CIRA’s total precipitable water product in Figures 1a and 1b depict two separate atmospheric rivers impinging on central California from 8 and 10 January 2017, respectively. The first wave transported a plume of tropical moisture from the south-southwest, which led to massive rainfall and high snow levels.  The second atmospheric river on the 10th was less directly connected to the tropics (coming in from the west-southwest), but nonetheless exhibited a well-focused transport of high moisture content.  Widespread flooding and mountain avalanches have resulted from these moisture plumes as the impacted California, as well as dramatic replenishment of reservoirs.

fig1_cira-tpw

Figure 1.  CIRA total precipitable water product (inches) valid at (a) 2100 UTC 8 Jan 2017, and (b) 2100 UTC 10 Jan 2017.

 

SPoRT’s real-time instantiation of the Land Information System (aka “SPoRT-LIS”) has nicely depicted the substantial replenishment of the moisture content in the soils over California.  The SPoRT-LIS is an observations-driven, ~3-km resolution run of the Noah land surface model that consists of a 33-year climatology spanning 1981-2013, and real-time output at hourly intervals sent to select NOAA/NWS partnering forecast offices.  The one-year change in the SPoRT-LIS total column soil moisture at 1200 UTC 11 January (Fig. 2) shows large increases over most of California, particularly in the higher terrain (given by blue and purple shading).  [At the same time, annual degradation in soil moisture can be seen across the central and eastern U.S.]  Interestingly, a substantial portion of California’s annual soil moisture increases has occurred in just the past week (Fig. 3; SPoRT-LIS total column soil moisture change over the past week).  One can certainly see the important role that atmospheric rivers play in being “drought busters”!

fig2_swetdiff365_20170111_12z_conus

Figure 2.  One-year change in the SPoRT-LIS total column relative soil moisture, valid 1200 UTC 11 January 2017.

 

fig3_swetdiff_20170111_12z_conus

Figure 3.  One-week change in the SPoRT-LIS total column relative soil moisture, valid 1200 UTC 11 January 2017.

 

A map of the SPoRT-LIS daily soil moisture percentiles from 11 January highlight the very wet anomaly over California relative to the 33-year soil moisture climatology (Fig. 4; similar to the pattern of annual soil moisture change from Fig. 2).  Blue shading denotes greater than or equal to the 98th percentile, thus indicating unusually wet soils on the tail end of the historical distribution.

fig4_rsm02percent_20170111_12z_conus

Figure 4.  SPoRT-LIS total column relative soil moisture percentile from 11 January 2017.

 

Finally, SPoRT is acquiring and assimilating in real time the Soil Moisture Active Passive (SMAP) Level 2 (L2) retrievals produced by NASA/JPL into an experimental version of the SPoRT-LIS.  SPoRT is a SMAP Early Adopter and has a funded project to conduct soil moisture data assimilation experiments with LIS and evaluate impacts on land surface and numerical weather prediction models.  Figure 5 shows SMAP L2 retrievals of the evening overpasses from ~0000 UTC 11 January.  Panel (a) is the 36-km resolution radiometer product, while panel (b) shows the enhanced-resolution product, obtained from the SMAP radiometer by using Backus-Gilbert optimal interpolation techniques to provide data on a finer (9 km) grid.  The enhanced-resolution product provides much more detail of the wet soils in California, while retaining the same overall regional patterns as the original 36-km retrieval.  Given the loss of the active radar component of the SMAP mission, SPoRT plans to assimilate both the 36-km and 9-km products separately, and compare results on model accuracy.

fig5_smap-l2-11jan2017

Figure 5. SMAP Level 2 soil moisture retrievals for the evening overpasses from ~0000 UTC 11 January 2017; (a) 36-km resolution product; (b) enhanced 9-km resolution product.

Stark contrast in Eastern U.S. soil moisture following Hurricane Matthew

Stark contrast in Eastern U.S. soil moisture following Hurricane Matthew

Major Hurricane Matthew left a trail of destruction in its wake from the Caribbean up through the U.S. East Coast.  As Hurricane Matthew tracked northward along a large portion of the U.S. Southeast Coast from Florida to North Carolina, the rainfall impacts worsened.  Figure 1 shows the weekly rainfall spanning 4-11 October, ranging from ~2-8 inches along the Florida East Coast to 10-20 inches in the eastern Carolinas.  Since antecedent soil moisture was highest in the eastern Carolinas (Fig. 2), the extreme rainfall led to the most serious flooding in this area.

fig1

Fig. 1.  Weekly rainfall totals from 4 – 11 October 2016.

fig2

Fig. 2.  Total Column (0-2 m) relative soil moisture prior to Hurricane Matthew’s impact on North and South Carolina, valid at 0000 UTC 7 October 2016.

Referring back to the precipitation totals in Fig. 1, we can see that there was a sharp rainfall gradient on the northwestern edge in the Middle Atlantic region.  Interestingly, this gradient in Hurricane Matthew’s rainfall coincided with a pre-existing transition zone between wet conditions near the Atlantic coast and drought conditions further inland from the Appalachians through New England.  The net result was to accentuate the wet-dry contrast already in place.  The animation in Fig. 3 highlights this contrast nicely by presenting the SPoRT-LIS daily total-column relative soil moisture percentiles from 1-12 October.  The percentiles are based off a 1981-2013 daily soil moisture climatology that SPoRT produced from its ~3-km resolution SPoRT-LIS simulation.  By 9 October, notice the incredible transition from excessively wet soil moisture exceeding the 98th percentile (Carolinas through the southern half of Delaware) to extremely dry soil moisture less than the 5th percentile across Pennsylvania into the Northeast (as well as much of the inland Southeastern U.S.).  In fact, total column soil moisture values are less than the 2nd percentile over a large part of Ohio, Pennsylvania, New York, and the New England states, indicative of the ongoing severe drought there.

fig3_loop

Fig. 3. Daily animation of SPoRT-LIS total column relative soil moisture percentile from 1 to 12 October 2016.

U.S. Deep South flooding as depicted by NASA’s SMAP satellite and SPoRT-LIS

U.S. Deep South flooding as depicted by NASA’s SMAP satellite and SPoRT-LIS

A significant flooding event occurred over the U.S. Deep South from 8-10 March 2016 due to a slow-moving low pressure/front from southern Texas to the Mississippi River, combined with a deep tropical moisture plume.  Tremendous rainfall totals of 4-8″+ were depicted by the Multi-Radar Multi-Sensor (MRMS) 1-km gauge-corrected radar rainfall estimate product for consecutive 24-hour periods ending 1200 UTC 9 March and 10 March 2016 (Fig. 1).  The MRMS gridded product provides short-term input precipitation estimates to the real-time Land Information System (LIS) run at the NASA Short-term Prediction Research and Transition (SPoRT) Center.

Fig1_MRMS2dayPrecip

Fig. 1.  Rainfall estimates from the Multi-Radar Multi-Sensor (MRMS) gauge-adjusted radar product for the 24-h period ending (a) 1200 UTC 9 Mar 2016, and (b) 1200 UTC 10 Mar 2016.

The soil moisture response to the heavy rainfall was captured nicely by NASA’s Soil Moisture Active-Passive (SMAP) satellite Level 2 retrieval product of 0-5 cm volumetric soil moisture for the early morning overpass across the Central U.S from 9 March (Fig. 2a).  Very high retrieved volumetric soil moisture of 0.45 or higher is seen from eastern Texas across much of northern Louisiana and southern/central Arkansas, aligned well with the areas that received the heaviest rainfall.  The corresponding SPoRT-LIS modeled soil moisture analysis for the 0-10 cm layer of the Noah land surface model (Fig. 2b) shows a reasonable agreement with the SMAP retrieved soil moisture but with slightly less dynamic range than the SMAP data — a reasonable result given that the SMAP retrieval is valid over a shallower, near-surface layer than the LIS top model layer.

Fig2_SMAPL2_LIS

Fig. 2.  (a) Soil Moisture Active-Passive (SMAP) 0-5 cm volumetric soil moisture retrieval valid 1223 UTC 9 Mar 2016, and (b) corresponding SPoRT-Land Information System (LIS) 0-10 cm volumetric soil moisture analysis valid 1200 UTC 9 Mar 2016.

The SPoRT-LIS total column relative soil moisture (RSM) has been found to qualitatively correlate with areas of river/areal flooding when exceeding ~60% across northern Alabama.  The depiction of total column RSM from the early morning of 10 March shows a large area exceeding 65% (blue  shading in Fig. 3a) across eastern Texas, northern Louisiana, and southern/central Arkansas.  The weekly change in total column RSM (Fig. 3b) highlights the regions that experienced the largest increases in soil moisture in response to the heavy rainfall.  As the soil approaches saturation/field capacity, most new rainfall goes directly to runoff, thereby exacerbating the flooding situation.

Fig3_LISrsm02m

Fig. 3.  SPoRT-LIS analysis valid 1200 UTC 10 Mar 2016 of (a) total column relative soil moisture (RSM), and (b) one-week change in total column RSM.

Another product available from the real-time SPoRT-LIS is the total column RSM percentile, which shows how anomalous the current soil moisture conditions are relative to a historical, 33-year climatological database of modeled soil moisture. The percentile product from the morning of 10 March (Fig. 4) shows that areas of eastern Texas and northwestern Louisiana (and a few other spots) exceed the 98th percentile for the current day — indicating that these present-day soil moisture values are about the most moist it has been in the last 33+ years for 10 March.

Notice that there are a few anomalous “bulls-eyes” of dry percentiles in southern/eastern Arkansas.  These areas are caused by corrupt input precipitation data driving the SPoRT-LIS land surface model simulation.  The issue is currently being corrected by the operational organizations managing the rain gauge input.  However, it should be noted that SPoRT is working to implement near real-time data assimilation of the SMAP Level 2 soil moisture retrievals into its LIS simulation.  Routine assimilation of SMAP satellite soil moisture will help correct anomalies caused by poor input precipitation, thereby resulting in more robust soil moisture analyses for situational awareness and disaster-response applications.

Fig4_percentile_20160310

Fig. 4. SPoRT-LIS total column RSM percentile valid 1200 UTC 10 Mar 2016.

Finally, the areas of active flooding at U.S. Geological stream gauges and the NOAA/NWS flood watch/warning map are given in Fig. 5 for the afternoon of 10 March.  The axis of flash flood warnings (dark red color) aligns quite well with the total column RSM percentiles exceeding the 98th percentile in Fig. 4, whereas the broader footprint of all flood warnings/watches corresponds closely with the total column RSM above the 65% value (blue shading in Fig. 3a).

Fig5_flooding

Fig. 5.  Plot of U.S. Geological Survey stream gauges with active flooding (top), and NOAA/NWS active [flash] flood watches and warnings (bottom-right) for the afternoon of 10 Mar 2016.

From drought to flooding in less than a week over the Carolinas, as depicted by SPoRT-LIS

A closed upper low over the Southeastern U.S. combined with a deep tropical moisture connection with Hurricane Joaquin led to historic rainfall and flooding over North and especially South Carolina over the weekend.  A wide swath of central South Carolina from the coast to Columbia received over 20 inches of rainfall in the past week (Fig. 1), much of it in the last 2-3 days.  Figure 2 shows the NASA Integrated Multi-satellitE Retrievals for GPM (IMERG) 24-h rainfall estimates displayed in AWIPS II compared to the official NWS/River Forecast Center rainfall estimate for the period ending 1200 UTC on 4 October.  This is erasing the prevailing drought in the Carolinas, which still had moderate to severe drought in the most recent U.S. Drought Monitor weekly product valid 29 September (Fig. 3).

SPoRT’s real-time configuration of the NASA Land Information System (SPoRT-LIS) runs the Noah land surface model to generate a “best modeled” soil moisture estimate at ~3-km resolution for enhanced situational awareness and input to local/regional numerical weather prediction models.  The SPoRT-LIS was assessed during summer/fall 2014 by the NOAA/NWS weather forecast offices (WFOs) at Houston, TX, Raleigh, NC, and Huntsville, AL. Following an expansion to a full Continental U.S. domain, the SPoRT-LIS was also evaluated more informally by the NWS WFOs at Tucson, AZ and Albuquerque, NM this past summer.  The primary areas of utility has been in drought monitoring and assessing areal and river flooding potential.  However, the Southwestern U.S. offices applied SPoRT-LIS soil moisture fields to enhance situational awareness for wildfire and blowing dust situations as well. Overall, a majority of the users during these assessments expressed substantial utility of the product due to a lack of other real-time high-resolution soil moisture products, and were confident enough to use the product as part of operational, public forecasts.

This extreme rainfall event in the Carolinas was captured nicely by the real-time SPoRT-LIS, which depicted some of the most dramatic changes in total column soil moisture ever documented by SPoRT collaborators.  Figure 4 compares the SPoRT-LIS 0-2 m total column relative soil moisture (RSM) from 28 September (left panel) and 5 October (right panel), with Figure 5 highlighting the 1-week change in 0-2 m RSM as displayed in AWIPS II.  The RSM represents how the volumetric soil moisture scales between wilting (0%) and saturation (100%) for a given soil composition, where the wilting point indicates that vegetation can no longer extract moisture from the soil and saturation indicates no more infiltration is possible (thus all new precipitation goes to runoff). Previous experience by the Huntsville WFO found that total column RSM values of ~60% and above tend to indicate an enhanced threat for areal and river flooding over northern Alabama; however, these thresholds can vary depending on river basin properties and regional soil composition.

Values of total column RSM typically ranged from ~25-35% on 28 September, prior to the significant rain event.  However, by 5 October, total column RSM increased to well above 65% in most areas of central South Carolina, and parts of southern and far western North Carolina.  The maximum weekly change in 0-2 m RSM (Fig. 5) exceeds 58% in central South Carolina — a value never documented in the recent years of real-time SPoRT-LIS output!  Most areas of SPoRT-LIS 0-2 m RSM exceeding ~60% correspond to areas of active minor to major river flooding across parts of southern Virginia and the Carolinas, as depicted in the USGS/NOAA river gauge network this morning (Fig. 6).

Finally, SPoRT is producing an experimental daily, real-time soil moisture percentile product based on a 33-year LIS-Noah county-by-county soil moisture climatology.  The soil moisture percentile map indicates where the current 0-2 m RSM soil moisture values lie in the present day’s historical soil moisture distribution for every county in the Continental U.S. The percentile product valid at 1200 UTC 27 September and 4 October is shown in Figure 7.  Primarily dry soil moisture values between ~5th-30th percentile are prevalent across the Carolinas on 27 September, corresponding reasonably well to the U.S. Drought Monitor moderate to severe drought areas from Figure 3. However, after the 10-20+ inches of rainfall over the past week, the 4 October soil moisture percentiles completely reversed across the region, with values > 98th percentile occurring in central South Carolina where the most severe flooding is taking place.  SPoRT plans to develop a brief training module on this percentile product prior to dissemination for display in AWIPS II at NWS WFOs, along with the current suite of SPoRT-LIS fields already available in AWIPS II.

Fig. 1. NWS River Forecast Center rainfall analysis for the week ending 1200 UTC 5 October 20125.

Fig. 1. NWS River Forecast Center rainfall analysis for the week ending 1200 UTC 5 October 2015.

Fig. 2. Comparison of NASA Integrated Multi-satellitE Retrievals for GPM (IMERG) rainfall estimate to the NWS/River Forecast Center analysis for the 24-hour period ending 1200 UTC 4 October 2015.

Fig. 2. Comparison of NASA Integrated Multi-satellitE Retrievals for GPM (IMERG) rainfall estimate to the NWS/River Forecast Center analysis for the 24-hour period ending 1200 UTC 4 October 2015.

Fig. 2. U.S. Drought Monitor weekly drought product valid 29 September 2015.

Fig. 3. U.S. Drought Monitor weekly drought product valid 29 September 2015.

Fig. 3. SPoRT-LIS total column (0-2 m) relative soil moisture valid on (left panel) 28 September, and (right panel) 5 October 2015.

Fig. 4. SPoRT-LIS total column (0-2 m) relative soil moisture valid on (left panel) 28 September, and (right panel) 5 October 2015.  Masked white areas represent water or urban pixels.

Fig. 4. One-week change in SPoRT-LIS total column relative soil moisture for the week ending 5 October 2015, as displayed in AWIPS II.

Fig. 5. One-week change in SPoRT-LIS total column relative soil moisture for the week ending 5 October 2015, as displayed in AWIPS II.  Maximum weekly change value > 58% is highlighted by the cursor position.  Masked black areas represent water or urban pixels.

Fig. 6. USGS and NWS River Forecast Center river gauge plot for the morning of 5 October 2015. River gauges experiencing flooding are indicated by the legend in the lower-right.

Fig. 6. USGS / NWS River Forecast Center river gauge plot for the morning of 5 October 2015. River gauges experiencing flooding are indicated by the legend in the lower-right.

Fig. 5. Experimental SPoRT-LIS total column relative soil moisture percentile product, valid at 1200 UTC on (left panel) 27 September, and (right panel) 4 October 2015.

Fig. 7. Experimental SPoRT-LIS total column relative soil moisture percentile product, valid at 1200 UTC on (left panel) 27 September, and (right panel) 4 October 2015.  Masked white areas represent water or urban pixels.

Applied Meteorology Unit Provides Local Weather Model using SPoRT Datasets for Orion Flight Test

The inaugural Orion flight test successfully lifted off from Space Launch Complex 37 at Cape Canaveral Air Force Station aboard a Delta IV Heavy rocket the morning of 5 December (Fig. 1), following a scrubbed launch attempt the previous day. Orion is designed to take humans beyond Earth orbit into deep space, including missions to an asteroid and eventually Mars.

Fig 1. A Delta IV Heavy rocket lifts off from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida carrying NASA's Orion spacecraft on an unpiloted flight test to Earth orbit. (photo credit: NASA)

Figure 1. A Delta IV Heavy rocket lifts off from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida carrying NASA’s Orion spacecraft on an unpiloted flight test to Earth orbit. (photo credit: NASA)

The Applied Meteorology Unit (AMU) operated by ENSCO, Inc. at the Cape Canaveral Air Force Station, Florida has transitioned a high-resolution configuration of the Weather Research and Forecasting (WRF) numerical weather prediction (NWP) model to support ground and launch operations at the Eastern Range (ER) and Wallops Flight Facility (WFF). The AMU-WRF runs a nested modeling domain with the highest-resolution nest (1.33-km grid spacing) centered on the ER launch facility (Fig. 2) and uses two initialization datasets from NASA/SPoRT: (1) Land Information System soil moisture and soil temperature data, and (2) the high-resolution (2-km) northern hemispheric sea surface temperature product.

Figure 2.  Grid setup of the AMU-WRF model as transitioned into operations at the 45 WS.

Figure 2. Grid setup of the AMU-WRF model as used by the 45th Weather Squadron.

The ER and WFF require high-resolution numerical weather prediction model output to provide more accurate and timely forecasts of unique weather phenomena that can affect NASA’s Space Launch System, Launch Services Program, and Ground Systems Development and Operations Program daily operations and space-launch activities. Global and national-scale models cannot properly resolve important mesoscale features due to their horizontal resolutions being much too coarse.

Daily and weekly weather forecasts issued by the 45th Weather Squadron (45 WS) are used as decision tools for their day-to-day and launch operations at the ER. The 45 WS and vehicle Launch Weather Officer (LWO) use NWP models as a guide for these weather forecasts. Forecasters have found the AMU-WRF model performance quite useful. It has frequently been the preferred model to help accurately identify complex, small-scale boundary interactions. Of particular note, its rapid hourly update capability adjust to dynamic changes in weather features, aiding the LWO during sensitive ground and launch operations that require specific timing accuracy.

During the Orion launch operations on 4 and 5 December 2014, the LWO relied on AMU-WRF low-level wind, fog and precipitation output variables as part of their forecasts leading to a successful launch. Figures 3 and 4 show five-hour forecast AMU-WRF output of 10-m wind gust and forecast radar reflectivity as displayed in the AWIPS II at the 45 WS, valid at the beginning of the launch window (1200 UTC 5 December). The forecast radar reflectivity image (Fig. 4) suggested that the rain shower activity would be primarily south and west of the launch complex at the beginning of the launch window, which corresponded fairly well with the validating Melbourne, FL radar image in Figure 5. The combination of shower activity movement from northeast to southwest and little indication of forecast precipitation upwind of the launch complex suggested a favorable weather outcome for launch.

Figure 3.  AMU-WRF 5-hour forecast 10-m wind gusts as displayed in the 45 WS AWIPS II, valid 1200 UTC 5 December 2014 (7 am EST).

Figure 3. AMU-WRF 5-hour forecast 10-m wind gusts as displayed in the 45 WS AWIPS II, valid 1200 UTC 5 December 2014 (7 am EST).

Figure 4.  AMU-WRF 5-hour forecast radar reflectivity as displayed in the 45 WS AWIPS II, valid 1200 UTC 5 December 2014 (7 am EST).

Figure 4. AMU-WRF 5-hour forecast radar reflectivity as displayed in the 45 WS AWIPS II, valid 1200 UTC 5 December 2014 (7 am EST).

Figure 5.  Validating radar reflectivity at 1207 UTC 5 December 2014 (7:07 am EST), approximately corresponding to the time of the Orion launch aboard the Delta IV Heavy rocket.

Figure 5. Validating radar reflectivity at 1207 UTC 5 December 2014 (7:07 am EST), approximately corresponding to the time of the Orion launch aboard the Delta IV Heavy rocket.

Powerful cold front blasting Plains with high winds and blowing dust

A strong cold front is ushering in markedly colder air for much of the central and eastern U.S. over the next several days.  The cold front today is highlighted by extreme temperature contrasts over the Southern Plains, with high winds and blowing dust along and behind the front as it surges southward through Colorado and Kansas.  Figures 1 and 2 show the VIIRS dust RGB images over the Plains at 1906 to 2049 UTC, respectively.  One can easily identify the increase in dust coverage (given by the darker pink colors) by 2049 UTC over southeastern Colorado as the front propagates southward.  A corroborating surface analysis valid at 2043 UTC in Figure 3 depicts visibility reductions at Lamar, CO (LAA; 2 miles), La Junta, CO (LHX; 1 mile), and Pueblo, CO (PUB; 3 miles) in southeastern Colorado.  Notice temperatures in the 80s across the Oklahoma and Texas Panhandles, while temperatures are in the 20s and 30s across northeastern Colorado and northwestern Kansas.  Quite the contrast!

Figure 1.  VIIRS dust RGB image valid at 1906 UTC 10 November 2014.

Figure 1. VIIRS dust RGB image valid at 1906 UTC 10 November 2014.

Figure 2.  Same as Figure 1, except valid at 2109 UTC 10 November 2014.

Figure 2. Same as Figure 1, except valid at 2049 UTC 10 November 2014.

Figure 3.  Surface analysis valid 2043 UTC 10 November 2014.

Figure 3. Surface analysis valid 2043 UTC 10 November 2014.

Widespread rainfall leads to improved soil moisture and drought classification

We are in the third and final month of assessing SPoRT’s real-time version of LIS running the Noah land surface model. The assessment is being conducted at the NWS forecast offices in Huntsville, Houston, and Raleigh to determine the utility of SPoRT-LIS for monitoring drought and areal flooding potential. The past 1-2 weeks featured substantial rainfall that occurred over a large portion of the central and eastern U.S.  Much of this precipitation was associated with a deep trough that progressed from the Southern Plains to the U.S. East Coast from 13-16 October.  Fairly widespread rainfall amounts exceeding 5 inches occurred over portions of eastern Oklahoma, south-western Missouri, western Arkansas, and in a swath extending from southeastern Arkansas to the southern Appalachians (Fig. 1).

Fig 1.  Depiction of 7-day rainfall estimates from the Stage IV radar+gauge product, ending 1200 UTC 16 October 2014.

Figure 1. Depiction of 7-day rainfall estimates from the Stage IV radar+gauge product, ending 1200 UTC 16 October 2014.

One of the SPoRT-LIS fields that forecasters have found quite useful during the assessment is the one-week change in total column relative soil moisture (RSM, 0-2 m).  The RSM is the ratio of the current volumetric soil moisture between the wilting and saturation points for a given soil type, with values scaling between 0% (wilting) and 100% (saturation).  In response to the recent substantial rainfall over the Deep South, the LIS total column RSM increased by 8-24+% over a large area (Fig. 2) approximately corresponding to the areas that received 4 or more inches of rainfall in the past week given by the orange and red shading in Figure 1. This beneficial rainfall led to the improvement of the U.S. Drought Monitor classification by 1-2 classes over portions of Kansas, Oklahoma, Texas, extending into Alabama, Tennessee, and northern Georgia (Fig. 3).  The most recent U.S. Drought Monitor product issued on 14 October (Fig. 4) shows that all drought classes have been removed over northern Alabama, Tennessee, and Kentucky.

Fig 2.  SPoRT-LIS one-week change in total column (0-2 m) relative soil moisture valid 1200 UTC 16 October 2014.

Figure 2. SPoRT-LIS one-week change in total column (0-2 m) relative soil moisture valid 1200 UTC 16 October 2014.

Fig 4.  One-week change in the U.S. Drought Monitor classifications, from 7 to 14 October 2014.

Figure 3. One-week change in the U.S. Drought Monitor classifications, from 7 to 14 October 2014.

Fig 3.  U.S. Drought Monitor classification valid 14 October 2014.

Figure 4. U.S. Drought Monitor classification valid 14 October 2014.