Search Results

You are looking at 1 - 10 of 12 items for :

  • Annual Weather Summaries in Monthly Weather Review x
  • All content x
Clear All
D. M. Rodgers, M. J. Magnano, and J. H. Arns

inhibited Gulf moisture flux into thecentral states, thus limiting the number of MCCsduring this normally active time of year.3. Case examples The following selection of four case examples illustratcs that large mesoscalc convective systems maybe spawned within a variety of synoptic flow regimes.Each example is discussed in regard to the positionof the MCC relative to midtroposphcric features asrevealed in 500 mb analyses. Of course, a number ofconditions must co-exist to support MCC development

Full access
Lixion A. Avila, Richard J. Pasch, Jack L. Beven, James L. Franklin, Miles B. Lawrence, Stacy R. Stewart, and Jiann-Gwo Jiing

require the issuance of watches or warnings. Tropical wave records kept since 1967 indicate that most eastern North Pacific tropical cyclones are associated with westward-moving synoptic-scale disturbances, or tropical waves ( Avila and Guiney 2000 ). In general, these waves amplify and trigger tropical cyclones when they reach this basin, where climatologically favorable conditions for tropical cyclogenesis such as low-level cyclonic vorticity, high moisture, and low shear prevail ( Gray 1968 ). This

Full access
Edward W. Ferguson, Frederick P. Ostby, and Preston W. Leftwich Jr.

706 94 122 104 20 332. Monthly summariesa. January Cold, arctic air dominated most of the United Statesduring January. Winter storm systems produced locallyheavy snow over much of the Plains with record breaking amounts of up to 14 inches reported in south-central Texas from ,a storm on 12-13 January. The coldtemperature and lack of significant moisture movingnorth from the Gulf of Mexico kept severe local stormsto a minimum. The

Full access
Lixion A. Avila, Richard J. Pasch, John L. Beven II, James L. Franklin, Miles B. Lawrence, and Stacy R. Stewart

-northeast over the Sea of Cortez and degenerated to a remnant low at 1800 UTC 19 September. The low moved inland near Guaymas, Mexico, and dissipated over the high terrain of the state of Sonora. Midlevel moisture from Javier spread northeastward over northern Mexico and the southwestern United States. k. Tropical Storm Kay: 4–6 October Kay formed on 3 October from an area of disturbed weather in the ITCZ centered several hundred miles southwest of mainland Mexico. There is little evidence that this

Full access
Lixion A. Avila and Jamie Rhome

marked by a well-defined northeast–southeast cyclonic wind shift extending from the surface to near 300 mb (hPa) and by the upward extension of moisture to near 200 mb trailing the wave axis, as shown in Fig. 2 . This wave eventually triggered the development of Hurricane Henriette. Vertical wind shear is a factor in controlling tropical cyclone genesis and intensification. Figure 3 shows the 200–850-mb vertical wind shear anomaly for July–October 2007. The figure reveals that stronger than normal

Full access
Richard J. Pasch, Eric S. Blake, Lixion A. Avila, John L. Beven, Daniel P. Brown, James L. Franklin, Richard D. Knabb, Michelle M. Mainelli, Jamie R. Rhome, and Stacy R. Stewart

communities isolated. Moisture and locally heavy rains also spread over portions of northwestern Mexico and the southwestern United States. Twenty neighborhoods were flooded by rainfall from the remnants of John in Ciudad Juarez, located across the border from El Paso, Texas. Around 76 mm of rain fell in El Paso, causing some flooding and closure of roads in that area. k. Hurricane Kristy, 30 August–8 September Kristy developed from a tropical wave that crossed the west coast of Africa on 13 August and

Full access
Lixion A. Avila and John L. Guiney

positioning the center of the storm and the rainbands. Heavy showers and gusty winds were observed primarily in the Gulf of California. Moisture from the storm reached the southwestern United States. Since Frank was a threat to Baja California, tropical storm watches and warnings were required for a portion of this area. g. Hurricane Georgette, 11–17 August Georgette’s origin can be traced back to a tropical wave that appeared in the far eastern tropical Pacific Ocean on 4 August. This wave was likely the

Full access
Edward W. Ferguson, Frederick P. Ostby, and Preston W. Leftwich Jr.

distribution of tornadoes in 1986. Total summed over statesgives 771 because of "border crossers." Numbers in parentheses are tornadodeaths. This dearth of activity resulted from a prevailingupper flow that steered most storm systems along theU.S./Canadian border. This type pattern fails to transport needed low level moisture northward from theGulf of Mexico. As a result, much of the central partof the nation experienced abnormally warm, but excessively dry, conditions during the month.b. February

Full access
Miles B. Lawrence

-central California coast about 24 h later. Clouds and precipitation associated with the remnant circulation aloft moved northward on 19 and 20 August, through northern California, Oregon, Washington, and southern British Columbia. On 20 August, this moisture was incorporated into the eastern part of a large offshore extratropical cyclone associated with the remnant of Hurricane Guillermo. Rainfall totals ranged from 10 to 30 mm over coastal areas of central California. A maximum of 55.1 mm was recorded

Full access
John A. Augustine and Kenneth W. Howard

conditions for convection existed during1985, mean patterns of the divergence of Q vectors(Hoskins et al., 1978), temperature advection, moisture, and lapse rates, were compared with those of1984--a relatively inactive year. With routines developed by Barnes (1985), the quasi-geostrophic (QG)equation, as formulated by Hoskins et al. (1978), (Hoskins and Pedder, 1980), was used to diagnose the divergence of Q over the central United States. This parameter, together with stability information, are usedto

Full access