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Ernani de Lima Nascimento, Gerhard Held, and Ana Maria Gomes

Paulo; the crisscrosses (×) indicate the position of the SBKP METAR site and SBMT upper-air site. A brief analysis of the tornado structure and cloud-base morphology is performed based on selected still images extracted from the videographic documentation; other characteristics of the parent storm are discussed through radar data analysis. In addition, the synoptic-scale conditions that prevailed around the time of the tornadic event are investigated from an ingredients-based perspective ( Doswell

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Howard B. Bluestein

Klemp (1985), using evidence drawnfrom three-dimensional numerical simulations, haveattributed the formation of the wall cloud to theupward dynamical forcing of cool, negatively buoyant,relatively humid outflow air from a region of precipitation. Bluestein and Parks (1983) have describedthe wall-cloud formation process as the appearance * Present affiliation: On sabbatical leave at the National Centerfor Atmospheric Research, Boulder, CO 80307. The NationalCenter for. Atmospheric Research is

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Gregory S. Forbes and Jonathan H. Merritt

. The vortices are readilydiscernible in satellite imagery, in which they take one of three forms: a miniature comma cloud, a swirl ofcloud bands (resembling a miniature tropical storm) or a swirl of cloud streets. Despite their impressiveappearance in satellite imagery, these vortices are usually relatively mild in comparison with other lake-effectstorms and produce only gusty winds and brief snow squalls as they move onshore. The vortices are accompaniedby a slightly lowered surface pressure and a

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Robert F. Adler, Douglas D. Fenn, and Douglas A. Moore

Weather Central, Offutt Air Force Base, Omafia, NE 68113 (Manuscript received 19 May 1980, in final form 17 November 1980) ABSTRACT A dark, spiral feature is noted in the geosynchronous satellite visible image of the top of a thunder storm which also has a Doppler radar-observed mesocyclone. Although the evidence is not conclusive, the feature may represent cyclonic rotation at cloud top associated with the pre-tornado mesocyclon-.1. Introduction On 20 May 1977

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Klaus P. Hoinka and Dietrich Heimann

east of the front it risesas much as 5 hPa within a strip a few 100 kin wide tothe west of the front. The maximum pressure gradientoccurs close to the north rim of the Pyrenees. (iii) Temperature and frontal weather.' The surfacetemperatur.e drops continuously to the rear of the frontwhile it is rather homogeneous over the prefrontal area.A 6/8 to 8/8 coverage of low strato-cumulus clouds isobserved west of the front while east of it the sky isalmost cloud free. Only weak drizzle occurs near

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Andreas Dörnbrack, Sonja Gisinger, Michael C. Pitts, Lamont R. Poole, and Marion Maturilli

1. Introduction The “picture of the month” as presented in this short contribution is not a photo of the sky spontaneously shot from a digital camera. The picture as displayed in Fig. 1 is a combination of spaceborne measurements by the Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument on board the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations ( CALIPSO ) satellite during one of several Arctic overpasses on 30 December 2015 and a high-resolution short

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Joseph H. Golden

Floridacoast where the prevailing southwesterly troposphericflow interacted with the sea breeze induced by theFlorida peninsula. There have also been numerous reports of funnelclouds over the Everglades west of Miami, in association with lines of cumulus congestus or cumulonimbus clouds (E. J. Zipser, 1970, private communication; Senn, 1978). R. L. Holle (1981, private communication) has noted that dozens of funnel cloudswere observed during the 1971-80 summer FloridaArea Cumulus Experiment (FACE

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Bradley M. Muller, Christopher G. Herbster, and Frederick R. Mosher

the coastline, the cloud-free eye is 6–7 km in diameter, but shrinks to 2–3 km as it turns from moving southwestward to moving toward the east. The shrinkage of the eye is similar to that of von Kármán vortices seen downwind of islands ( Young and Zawislak 2006 ), suggesting a nonsteady-state boundary layer flow characterized by pressure gradient force, centrifugal force, and friction. Satellite images at 1445, 1500, and 1530 UTC ( Fig. 3 ) show a sharp boundary between clear and cloudy air

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Clifford F. Mass and David P. Dempsey

in theimmediate offshore waters ranged from 8- to 10-C.Although western Washington, Oregon and BritishColumbia were virtually cloud free, over the Pacificthere was extensive convective cloudiness that formed20-100 km off the coast as cold, continental airbecame destabilized and moistened by the warmerwater below. Such convection, frequently observedoff the east and Gulf coasts of the United States, isunusual in the Pacific Northwest where offshore flowin winter is relatively infrequent and rarely

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Brandon J. Vogt and Stephen J. Hodanish

work is that there is no comprehensive cloud-to-ground (CG) lightning climatology for the state of Colorado in the formal literature. The most formal comprehensive work that analyzes CG lightning in Colorado was published by Lopez and Holle (1986) . The authors examine a single year (1983) of CG lightning data collected over the state’s northeast region where they found the lightning activity to be mainly a warm season event, with a large majority of the flashes occurring June through September

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