The elevated mixed layer (EML) can be an important aspect for severe thunderstorm forecasting. Because its thermodynamic characteristics vary as it moves eastward, tracking the EML is a crucial part of the forecasting process, something that previously has been quite challenging owing to the limited spatial and temporal resolution of observed soundings and numerical weather prediction (NWP) output. New satellite capabilities allow for improved monitoring/tracking of the EML. These include the 7.34-µm band on the Geostationary Operational Environmental Satellite-R series, as well as microwave instruments on polar-orbiting satellites used in the advected layer precipitable water product. Herein it is demonstrated—using several case studies—how using a combination of these products, in tandem with sounding data and NWP output, allows the forecaster to efficiently monitor the EML at greater spatial and temporal resolutions.

To date, the use of Doppler radar (WSR-88D) in wildland fire operations has been limited, with tactical applications focused on analyzing ambient atmospheric features. This paper presents geographically diverse analysis of radar-observed wildland fire convective plumes to determine indicators of plume mode for tactical decision support. Through the visualization of buoyancy via thermal bubbles and vertical plumes, plume mode is revealed via WSR-88D interrogation of three Southern Great Plains grass/shrub fires and two timber fires in Texas and California. Analogous to thunderstorm convective modes, past research has identified two distinct plume modes of wildland fire: multicell and intense convective plume. Multicell plume mode is characterized by a series of shallow discrete cells that move away from the fire’s main buoyancy source, with successive cells rising, expanding, and replacing cells from the updraft source. This process, known as the thermal bubble concept, occurs most notably in strong vertical wind profile environments with a strong advection component. These cells or thermal bubbles are observed via WSR-88D data for three Southern Great Plains cases. Intense convective plumes are observed to be vertical with the low-level reflectivity maximum and maximum echo top juxtaposed and occurrence is confined to weak wind environments; these plume structures are identified in the two timber fire cases. An important WSR-88D signature, the back-sheared convective plume (hereafter BSCP), is identified in terms of transverse vortices and vortex rings, which may imply enhanced combustion rates due to increased turbulent mixing. Determination of plume convective mode via radar offers meteorologists the ability to detect changes in plume mode and to provide important tactical decision support information about fire behavior.

The Cooperative Institute for Research in the Atmosphere, via the Joint Polar Satellite System Proving Ground, developed an advectively blended layered precipitable water (ALPW) product that portrays moisture profiles at a common time across the grid. Using water vapor profile retrievals from the National Oceanic and Atmospheric Administration's Microwave Integrated Retrieval System (MiRS) aboard polar-orbiting spacecraft, the ALPW product is able to depict the moisture distribution for four atmospheric layers. The ALPW layers are advected forward in time every 3-h using Global Forecast System model winds. Advective blending offers a reduction to the visual limitations seen with traditional non-advected layered precpitable water (LPW) imagery, as satellite swath lines and data discontinuities largely are removed. Having the same temporal resolution as LPW imagery, the new ALPW product offers a more continuous and complete picture of the moisture distribution in these four atmospheric layers (surface-850 hPa, 850-700 hPa, 700-500 hPa, and 500-300 hPa). The advected product also is easier for forecasters to interpret as the analysis at a common time and grid makes the ALPW product comparable to operational model guidance. This paper demonstrates the utility of the ALPW product as a situational awareness tool by highlighting the environments associated with three recent high-impact flash flood events. Initial findings indicate that ALPW data have improved the detection capability for tracking deep tropospheric moisture plumes from source regions well-removed from the flash flood locations.

Low-level thermal ridges (LLTRs) have been identified as common meteorological features associated with wildfires in grass-dominated fuelscapes on the southern Great Plains.Analogous to the well-documented fire-effectiveness of West Coast thermal troughs, LLTRs on the Plains have a dramatic influence on wildland fire.Identification of these features in proximity to midlevel wind maxima has proven useful in forecasting the evolution, intensity, and areal scope of regional wildfire outbreaks.This study will provide detailed meteorological analyses of fire-effective LLTRs on the southern Great Plains.The National Centers for Environmental Prediction's North American Regional Reanalysis and National Center for Atmospheric Research Data Reanalysis are used to investigate atmospheric characteristics of LLTRs associated with 11 widespread and destructive wildfire episodes on the southern Great Plains between 2006 and 2014.Atmospheric coupling of kinematic and thermodynamic processes that influence fire effectiveness are illustrated by a vertical profile and cross section.Composites and conceptual models derived from the analyses for conflagrations on the windward side of pronounced LLTRs are used for applications in forecasting southern Great Plains wildfire outbreaks.Examples illustrating the operational utility of LLTRs in wildland fire prediction are presented.Finally, comparative observations of environments with differing fire effectiveness are shown to suggest physical influences that exacerbate surface wildland fire behavior in proximity to these atmospheric features.

In June 2006, significant flooding and flash flooding impacted much of the mid-Atlantic region as a continuous supply of deep tropical moisture moved north from the subtropical Atlantic ahead of a slowmoving cold front. A 3-day period of heavy rain resulted in nearly 38.1 cm (15 in) of rain across portions of the northern mid-Atlantic with record flooding along the mainstem Susquehanna and Delaware Rivers. In September 2011, moisture associated with the remnants of Tropical Storm Lee resulted in a 24-h period of heavy rain over which rainfall totals approached 30.3 cm (12 in) across portions of central New York and northern Pennsylvania. Numerous river-stage records that were set in the June 2006 event were shattered along the mainstem Susquehanna River during the September 2011 flood. Damage estimates resulting from the flooding in both events were >2 billion dollars, and 22 lives were lost. Multiple counties across the northern mid-Atlantic were declared disaster areas. Both flood events were investigated to identify the similar meteorological features and patterns responsible for extreme rainfall. Several crucial similarities were identified that likely combined to produce historic socioeconomic and environmental impacts. One of the similarities was that each event had a well-established atmospheric river in place that provided the uninterrupted supply of deep tropical moisture. Additionally, although these events displayed many of the large-scale characteristics identified in previous flash flood classification schemes, both events were associated with the presence of coastal fronts that appeared to make these cases different from many otherwise similar and previously documented flood cases.

The National Weather Service issues Red Flag Warnings in agreement with land management agencies when relative humidity, wind speed, and fuels meet or exceed critical thresholds supportive of extreme burning conditions within a local vegetative and climatic regime. The degree to which relative humidity and wind speed exceed these local thresholds, however, is not quantified routinely via current warning products. This study will introduce a Red Flag Threat Index (RFTI) to express the severity of observed or forecast fire weather conditions. This Index, patterned after the widely-used Haines Index, incorporates forecast and/or observed 2-m relative humidity and 6-m wind speed and is derived by a summation of numerical terms for these commonly used variables in fire weather prediction. The value of these terms is determined from quartile rankings of nearly 2,300 critical fire weather observations across west Texas. With scores that range from 0 ("Non-Critical") to 10 ("Historically Critical"), the RFTI is intended to increase situational awareness for fire weather forecasters and to convey risk levels to fire managers and decision makers while providing an important tool in assessing the severity of critical fire weather relative to climatology. Utility of the RFTI is demonstrated through an analysis of its correlation to a pre-existing database of meteorological proximity observations for significant wildfire starts. This index is well suited for use in operational forecast environments and adaptable to any location or climate regime, especially those vulnerable to wind-driven fires in fine fuels.

In an effort to assist forecasters with the identification of favorable flash flood-producing environments, a synoptic classification study of flash flood events occurring in central New York and northeast Pennsylvania was completed following the Maddox et al. (1979) classification scheme. In total, 41 events covering a time period from January 1996 through September 2010 were investigated and subjectively classified as either Frontal (6 events), Synoptic (21 events), Meso High (2 events), Tropical (3 events), or Unclassified (9 events) type flash flood events. The classification was based on the 0000/1200 UTC 500 hPa patterns, the analyzed HPC surface map valid at the time of the initial flash flood report, and local radar animations. Using the local Weather Forecast Office (WFO) Binghamton BUFKIT model sounding archive, North American Mesoscale Model (NAM) and step mountain eta coordinate model (ETA), proximity soundings were analyzed using data interpolated to the forecast point closest to the initial report of flooding. Several variables were investigated to help establish values characteristic of each flash flood type. Results indicate Synoptic flash flood-producing environments were most common, however these events were associated with the widest range of parameter values examined in this study. Meanwhile, events with weak large scale forcing such as Meso High and Frontal flash flood scenarios were less common and were accompanied by a smaller range of parameter values prior to flood occurrence. Furthermore, results of this study suggest that some of the thresholds for the Binghamton area may be different than thresholds determined in previous studies for other parts of the country. _______________________________________ Corresponding author address: Christopher M. Gitro, NOAA/NWS 32 Dawes Dr. Johnson City, New York 13790 E-Mail: christopher.gitro@noaa.gov