WEATHER GUIDE MISSISSIPPI RIVER BASIN WATERWAYS · PDF fileunited states power squadrons draft...

WEATHER GUIDE

MISSISSIPPI RIVER BASIN WATERWAYS

UNITED STATES POWER SQUADRONS DRAFT REGION 12 WEATHER GUIDE MISSISSIPPI RIVER BASIN WATERWAYS

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iii Revised 28 Feb. 2006

This Guide is one of a group of marine-oriented publications offered by the United States Power Squadrons. Comments, suggestions or corrections relating to this or any other Learning Guides are not only welcome but solicited.

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The USPS Aquamarine trade dress of this publication (left side of front cover including text and graphics)

are registered trademarks of United States Power Squadrons. The Squadron Boating Course is a service mark of United States Power Squadrons.

One or more of these marks may be found in this publication. The cover design of this publication is a trademark of United States Power Squadrons.

Copyright 2006, United States Power Squadrons All rights reserved

Printed in the Unites States of America

United States Power Squadrons 1504 Blue Ridge Road

PO Box 30423 Raleigh, NC 27622

919-821-0281 888-FOR-USPS (367-8777)

Fax: 919-836-0813 1-888-304-0813 www.usps.org

This publication is designed to provide general information on boating safety, piloting and navigation. It was prepared by United States Power Squadrons and its members, and is sold with the understanding that professional nautical services are not being provided. Do not use this publication as a substitute for original sources of nautical information, including government publications, rules, regulations, laws and manufacturers’ recommendations, where appropriate. The subject matter of this publication is likely to become outdated over time, and may have changed since our last publication date. Consequently, you must research original sources of authority to update this material and ensure accuracy when dealing with specific “on the water” conditions or boating problems.


iv Revised 28 Feb. 2006

Table of Contents

Topic Page

Table of Contents iv

Acknowledgements and Disclaimer v

Chapter 1 Mississippi River Basin Waterways Overview 1 The Waterways

The Upper Mississippi Navigable Waterway U.S. Army Corps of Engineers River Map

Locks and Dams on the Upper Mississippi River

2 3 4 5

Chapter 2, Region 12 Boundaries, Climate 7 Region 12 Rivers, Climate

Severe Weather 8

11 Chapter 3 Migratory Systems 13

The Atmosphere Where Does Weather Come From?

What Systems Bring Good and/or Bad Weather? Highs and Lows

Fronts Hurricanes Tornadoes

Supercells and Microbursts

13 14 15 15 16 18 19 19

Chapter 4 Weather and Boating on the Mississippi River 21 A. Winds B. Islands

C. Storm Tracks D. Precipitation E. Lightning

F. Visibility G. Clouds H. Seas

I. Currents J. Tides

K. Boat Deck Weather Forecasting

21 30 32 35 37 38 39 40 40 41 41

Appendix A. Glossary of Terms

B. Geographical Boundaries C. Beaufort Table D. Cloud Pictures

E. Harbors of Refuge F. Weather and VHF-FM Radio Information

G. Sample Weather Log H. Graphics and Credits

43 44 49 50 51 52 53

54 56


v Revised 28 Feb. 2006

Acknowledgements

This document is made possible through the contributions of the following:

United States Army Corps of Engineers Material provided by the U.S.Corps of Engineers as a courtesy. Additional use requires a copyright.

Nationalatlas.gov En.wikipedia.org

USA Today University of Illinois ww2010 Project

(http://ww2010.atmos.uiuc.edu) USA Today and USPS Weather course

Graphics and Image products as identified with each as presented plus project generated graphics.

Disclaimer

This Weather Guide – Region 12 – Mississippi River Basin Waterways is written from the experiences of the authors and subject matter contributors. It is believed that this guide is accurate in its descriptions of the river and the weather events that can happen along and on the river. It does not cover all of the possibilities due to local situations along the Mississippi River or its tributaries. It is believed that the information contained within will give the reader appreciable knowledge on what information about the weather is required to be a responsible boater. The reader must use discretion with the information as it can differ from the reader’s personal experience, the reader’s interpretation of the content, or from the boating area familiar to the reader.


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Chapter 1 Mississippi River Basin Waterways Overview

The Mississippi River Basin is responsible for water drainage for 40% of the contiguous United States. See Fig. 1-1. These waters support great boating opportunities for the recreational boater. The United States Power Squadrons has defined this area as Region 12 and addresses weather, water, and boating in the Mississippi River Basin, as shown with the map, below. Region 12 geographical boundaries are defined in detail in Appendix B The region has been divided into Northern and Southern sub-regions. The United States Army Corps of Engineers (USACE) refers to the areas as Upper and Lower sub-regions. It is the intent of this discussion to address mainly the Northern Sub-Region although many of the concerns are common to all of the region’s boating areas. The other rivers in the Mississippi River Basin, such as the Missouri, the Ohio, the Tennessee, and the Arkansas Rivers will not be discussed. However, the concepts put forth herein can be applied to those rivers with the reader adjusting them to familiar local conditions where applicable.

Map from en.wikipedia.org

Fig. 1-1

The Mississippi River Basin has some of the most extreme weather conditions recorded in the United States. These extreme conditions usually occur starting in the early part of the boating season, the storm tracks will move from the south to the north through the basin as the season progresses from late spring into summer. For example, boaters in the St. Louis area will experience the severe thunderstorms, winds, and other types of precipitation about a month earlier than the boaters in the Minneapolis – St. Paul area. Likewise, the reverse is true in the fall of the year. The storm tracks move from north to south and the boaters in


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the St. Louis area will be the last to rid themselves of exposure to extreme weather conditions. By this time, the boating season further north has ended. The Northern Sub-Region of the basin definitely experiences the four seasons of the year. Recreational boating from late spring through summer into early fall will be the portion of the year where recreational boating is at its peak and will be the focus of this document. Each boater can prejudge daily weather conditions from the deck of the boat, so the observations of wind direction, estimated wind speed, cloud types and direction of motion, visibility, temperature and relative humidity can be used to determine near term weather conditions and potential changes to these conditions. The intent of the articles written in this document is to help the boater identify weather conditions from the “deck-of-the-boat.” This can be done independently of boat type, and for the most part, without any special instruments. However, certain easy to carry instruments will be suggested in the text that might be an aid to detecting atmospheric changes that can alert one to up-coming weather events.

The Waterways

The USACE is responsible for all of the navigable inland and coastal waterways in and around the United States. The USACE causes dredging operations to occur to clear the silt if the river silts in and to remove obstructions along the waterway. If a community or a private business requests shoreline improvements USACE is one of the approving agencies before work can commence. The USACE is responsible for all of the locks and dams along the river. They let “nature-take-its course” outside of local commercial and government areas of concern. The USACE maintains a set of charts for most inland waterways that may be purchased by recreational boaters from the USACE District Offices. The USACE has a charted system of mile marks from the beginning point of the Upper Mississippi River at Cairo, IL, mile zero (0), at the confluence of the Ohio and Upper Mississippi Rivers and thereby, marking every mile of the navigable river. St. Louis, MO is at mile 185 and Minneapolis, MN is at mile 857. Each page of the Upper Mississippi River charts covers 10 statute miles of waterway. Individual pages may be downloaded at no charge from the USACE website. On the water, the United States Coast Guard (USCG) maintains the aids to navigation. All daymarks have mile marker signs and are shown on the charts. www.noa.USACE.army.mil/NavCharts/UMRNavCharert.asp The USACE has developed the Inland Electronic Navigational Charts (IENC) that have higher spatial accuracy and are maintained with updates. They are available at no charge at www.tec.army.mil/echarts. Fig. 1-2 shows the scope of the Upper Mississippi River Basin that the USACE is the responsible to maintain.


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The Upper Mississippi River Navigable Waterway


Fig. 1-2

An example of a page from the USACE river chart book is in Fig. 1-3.


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U.S. Army Corps of Engineers River Map

Fig. 1-3

There are 29 lock and dams (L&Ds) on the Upper Mississippi River. They are either named or numbered. The USACE naming nomenclature started at the northern most L&D, St Anthony Falls, and then went downstream with their identification system. L&D #1 is also called the Ford lock and dam used by the Ford Motor Corporation for their vehicle assembly plant. L&D #2 is at Hastings, MN, and starts the uninterruptible numbering system to #27 at Alton, IL just north of St. Louis. There are two L&Ds #5. L&D #5A was inserted because the water behind #5 didn’t backup far enough upstream to support commercial traffic. So another L&D was added. There are water pools on the upstream side of the L&Ds. These pools range from 9 to 50 feet in depth. There is ample surface water for the boat traffic but the boater must be on guard not to get too close to the spillway while waiting to transit the lock. The undertow current can easily pull a recreational vessel into the lock complex with disastrous results. Every so often one reads about a boat going over the top of a dam. There are a series of buoys marking the


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approaches, but, with the exception of the St. Anthony L & D in Minneapolis, there are no safety cables or screens to stop boaters from "going over the top.” The upstream side of the L&D is also exposed to the wind and weather much more than the downstream side. Therefore, while waiting to go through the lock the upstream boater must pay particular attention to both wind and river current, whereas the downstream boater waiting to go upstream is protected from the wind and has mostly to contend with the current. While in the lock, the boater can frequently be challenged with the wind and the rising or lowering water. Both can be swirling around within the lock walls at a strength that makes keeping the boat secure against the lock wall somewhat of a challenge.

Fig. 1-4 shows the L&Ds in the Upper Mississippi River Basin.

Locks and Dams on the Upper Mississippi River


Fig. 1-4

Each chapter of this document discusses, defines or by some means illustrates the knowledge needed to boat safely on the Mississippi River and its tributaries. The following describes the chapters’ contents.


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Chapter 2: Region 12 – Defines its rivers and climate. Discusses the navigable rivers and their Locks and Dams, Region 12 and climate. Presented is an overview of the weather conditions that can be found within the Northern and Southern sub-regions plus where and when the severe weather areas might be during the boating season. Chapter 3, Migratory Systems. Introduces the reader to the general weather situation. It discusses types and general causes of weather within the Mississippi River Basin, and how to identify the conditions that precede those weather systems. Chapter 4, Weather and Boating on the River. Discusses winds, precipitation, fog, clouds, seas, currents and expected areas of exposure and protection along the Mississippi River Basin. As an added extra there is information on how to do Boat Deck Weather Forecasting. The Appendix contains special topics which include: a Glossary of Terms, the Region 12 Geographical Boundaries for each state within the region, Beaufort Table which can assist the reader in the estimating wind speed, a Cloud Picture Section, Information on Harbors of Refuge, information about Weather and VHF-FM Radio frequencies; and a Sample Weather Log form. The United States Power Squadrons wish you safe boating and encourages you to attend one or more of its safe boating classes.

UNITED STATES POWER SQUADRONS DRAFT REGION 12 WEATHER GUIDE Mississippi River Basin Waterways

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Chapter 2

Region 12 Boundaries & Climate

The geographical area of Region 12 covers the vast middle part of the forty-eight contiguous states. From south to north, the distance by latitude is 725 miles, encompassing a wide range of weather at any given time. It is, therefore, reasonable to divide the region into two sub-regions. The southern sub-region covers from 33°00” N to 38°30” N, a distance of 330 miles. The northern sub-region covers from 38°30” N to 45°05” N, a distance of 395 miles. The southern border of the southern region, 33°00” N, approximates the southern border of Arkansas. The dividing line, 38°30” N, goes through St. Louis, Missouri and is approximately 25.4 miles south of the confluence of the Mississippi and Missouri Rivers. See Fig. 2-1 and Fig. 2-2 below.

Region 12

Fig. 2-1


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Northern Sub-Region Navigable Rivers

Mississippi River: the United States Army Corps of Engineers (USACE) maintains a nine-foot channel depth from mile zero (0) at Cairo, IL to mile 857.6 in North Minneapolis, MN. The USACE also maintains a nine-foot channel depth in some of the Mississippi River tributaries. Northward beginning at 38°30” N some significant rivers are: Kaskaskia River: joins the Mississippi River at mile 117.4. USACE maintains the channel for 36

miles to Fayetteville, IL. Missouri River: joins the Mississippi River at mile 195.0. USACE maintains the channel to mile

734 at Sioux City, IA. Illinois River: joins the Mississippi River at mile 218. USACE maintains the channel to Chicago,

IL. Des Moines River: joins the Mississippi River at mile 361.5. USACE does not maintain the

river channel. Black River: joins the Mississippi River at mile 698.0 at La Crosse, WI. USACE maintains the

channel for 1.5 miles. Chippewa River: joins the Mississippi River at mile 763.4. USACE does not maintain the river

channel. St. Croix River: joins the Mississippi River at mile 811.3. USACE maintains the river channel to

mile 24.7 at Stillwater, MN. Minnesota River: joins the Mississippi River at mile 843.8. USACE maintains the channel to

mile 14.7. The river is highly commercial and has no significant pleasure boat facilities.

Southern Sub-Region

Mississippi River: In the southern sub-region the USACE maintains a nine-foot deep by 300-foot wide channel from 38o30”N south to the mouth of the river. The USACE also maintains a nine-foot depth in some of the Mississippi River tributaries. In the southern sub-region beginning at the southern boundary, 33o00” N, the significant rivers are: Red River: joins the Mississippi River at mile 303.9. USACE maintains the channel for

235 miles to above Shreveport, LA. Ouachita/Black Rivers: The Black River joins the Red River at mile 34.3 south of

Acme, LA, and begins 41.5 miles up river at the confluence of the Ouachita and Tensas Rivers near Jonesville, LA. USACE maintains a nine-foot channel to mile 299.7 north of Camden, AR. The river miles are continuous through both rivers

White River: joins the Mississippi River at mile 599. Above the junction with the Arkansas Post Canal, the USACE maintains a six-foot channel for 255 miles to Newport, AR.


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Arkansas Post Canal: joins the White River at mile 10 and the Arkansas River at mile 19. USACE maintains a nine-foot channel to the Arkansas River.

Arkansas River: Access from the Mississippi River to the Arkansas River is via the White River, Mile 599, into the Arkansas Post Canal at mile 10, joining the Arkansas River at mile 19. The USACE maintains a nine-foot channel in the Arkansas River to mile 397 where it joins the Verdigris River.

There is no navigable passage from the Mississippi River up the Arkansas River beyond Dam No. 2.

Verdigris River: joins the Arkansas River at mile 397. USACE maintains a nine-foot channel for 50 miles to Catoosa, OK.

St. Francis River: joins the Mississippi River at mile 672.3. USACE maintains a nine-foot channel for 338 miles to Wappapello, MO.

Obion River: joins the Mississippi River at mile 819.2. USACE maintains a nine-foot channel for 69 miles to Obion, TN.

Hatchie River: joins the Mississippi River at mile 773. USACE maintains a nine-foot channel for 140 miles to Bolivar, TN.

Wolf River: joins the Mississippi River at mile 738.5. USACE maintains a nine-foot channel for 15 miles to Memphis (Raleigh), TN.

Forked Deer River: joins the Mississippi River at mile 819.2. USACE maintains a nine-foot channel for 25 miles where the river splits into North and South forks.

South Fork-Forked Deer River: USACE maintains a nine-foot channel for an additional 69 miles to Jackson, TN.

North Fork-Forked Deer River: USACE maintains a nine-foot channel for an additional 6 miles to Dyersburg, TN.

Ohio River: joins the Mississippi River at Upper Mississippi River mile 0.0 at Cairo, IL or at Lower Mississippi River mile 957. USACE maintains a nine-foot channel for 981 miles to Pittsburgh, PA.

Tennessee River: joins the Ohio River at the Ohio River mile 934.5 at Paducah, KY. USACE maintains a nine-foot channel to mile 652.2 in Knoxville, TN.

Climate Region 12 is a large region influenced by several air masses, each with its own characteristics. Each air mass is discussed in more detail in Chapter 3. Region 12 represents over one-third of the United States in area, and consequently, has boating seasons that are extremely variable. Some areas are restricted by the severe seasonal weather changes and other areas are open all year round. This document assumes that the boater is in the prime boating season for the area of concern.


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REGION 12 SUB-REGIONS

Fig. 2-2

Northern Sub-Region

In the extreme northern part of the Northern Sub-Region, Minnesota, Wisconsin, Iowa, and Illinois have a limited warm weather boating season. Until the ice is completely gone and spring floods have receded, there is little or no boating in the northern parts of the Mississippi River Basin. Marinas are open from April through October from Dubuque, Iowa and north. The best weather in the extreme northern reaches of Region 12 is from mid-May through September with the very best from mid-June through mid-September. See Fig. 2-2.


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Proceeding southward from Dubuque, an increasing number of marinas are open year-round. Below the confluence with the Missouri River, almost all marinas are open all year. Conditions get steadily better further downstream into the Southern Sub-Region beginning at St. Louis, Missouri, because the winter weather moderates and the normal boating season extends from March into November.

Southern Sub-Region Moving south into the mid-section of the country one can minimize the winter season and maximize the boating season to the point where the hot, humid summer is marginally the worst season and winter is quite tolerable. At the southern limits of Region 12, some days in the summer can be the worst with temperatures and humidity in the 90’s. At the other extreme, in the winter, one can expect an occasional cold snap that causes brief freezing in most southern parts of Region 12. Spring and fall can offer the very best weather for boating with warm days and comfortable nights. The U.S. Coast Guard has published for winter boating: “Regarding winter boating “The Coast Guard has stated that boaters are more likely to die in winter accidents than during the summertime. One of every four accidents occurring in November and December when the water is cold, results in a fatality due to hypothermia.” The Coast Guard recommends winter boaters to wear layers of clothing topped by a “float-coat,” a waterproof jacket as buoyant as a personal floatation device. “Warm clothing will not help if you are unconscious,” the Coast Guard warns. Fig. 2-3 below illustrates the average high and low temperature for selected locations within Region 12 at certain months of the year.

Average High/Low Temperatures in 0F in Selected Cities Northern Sub-Region

CITY January April July October Mpls/St. Paul, MN 21.9/4.3 57.0/36.2 83.3/63.0 58.4/38.9 La Crosse, WI 25.5/6.3 59.7/37.1 85.2/62.8 61.1/40.1 Moline, IL 29.8/12.3 61.7/39.3 86.1/64.5 64.4/41.6 St. Louis, MO 37.9/21.2 66.7/46.5 89.8/70.6 68.3/48.2 Kansas City, MO 36.0/17.8 65.2/43.5 88.8/68.2 67.6/45.9

Southern Sub-Region Louisville, KY 39.9/24.9 66.8/46.0 87.0/69.8 68.4/48.5 Paducah, KY 41.9/23.9 68.4/45.6 88.6/67.7 70.8/45.2 Memphis, TN 48.6/31.3 72.4/47.1 92.1/72.9 75.1/52.5 Little Rock, AR 49.5/30.8 73.2/50.0 92.8/72.0 75.1/51.5

Fig. 2-3 The severe weather season starts in the south-central southern sub-region in late winter. In the spring the severe weather areas move north to Oklahoma, and Kansas.


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In late spring, the severe weather areas are in Nebraska, Kansas, Missouri, and Iowa, and by summer they are centering in Minnesota, and Wisconsin. By the fall of the year, the severe weather areas are less frequent and move towards the Ohio River valley. Winter fairly well shuts down severe weather from thunderstorms throughout the central part of the United States, only to start up again in March. See Fig. 2-4.

SEVERE WEATHER SEASONS

Fig. 2-4

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