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.

Low-level thermal ridges (LLTRs) have been identified as common meteorological features associated with wildfires in grass- ABSTRACT (Manuscript

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.

Gitro, C. M., and Coauthors, 2018: Using the multisensor advected layered precipitable water product in the operational forecast environment. J. Operational Meteor., 6 (6), 59-73, doi CHRISTOPHER GRASSOTTI NOAA/NESDIS Center for Satellite Applications and Research and University of Maryland, ESSIC/CICS-MD, College Park, MarylandThe 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. ABSTRACT (Manuscript