NAVNOTICE# 13 - MSO ST. LOUIS AOR SPRING FLOOD UPDATE

To: &nbspALL MARINERS
From: &nbspMSO St. Louis
Date: 3/27/98
Subject: MSO ST. LOUIS AOR SPRING FLOOD UPDATE
NAVNOTICE # 13

SUBJ: SITREP TWO - SPRING FLOOD OUTLOOK UPDATE
A. MY 031319Z MAR 98 NOTAL.
B. TELCON CWO3 HILDEBRAND (MSO STL)/MS. JANELL QUINLAN (ND EMA OPS)
27 MAR 98.
1. THE INFORMATION PROVIDED BELOW IS AN UPDATE TO REF A FOR MSO ST.
LOUIS' AOR.
2. DISCUSSION. THE PARAMETERS USED IN CALCULATING THE PROJECTIONS OF
RIVER STAGES ARE: CURRENT OBSERVED STATE OF STREAMFLOW, SOIL
MOISTURE, SNOW PACK, FUTURE PRECIP PATTERN, FUTURE TEMPERATURE
PATTERN, ANTICIPATED OPERATIONAL HYDROLOGIC CHANGES (RESERVOIR
RELEASES AND CANAL DIVERSIONS). WITH THIS INFORMATION THE RIVER
STAGE IS DETERMINED AND FLOOD CATEGORY ASSIGNED AS DESCRIBED IN
PARAGRAPH 3.
3. TERMINOLOGY.
A. MINOR FLOODING - A GENERAL TERM INDICATING MINIMAL OR NO PROPERTY
DAMAGE, BUT POSSIBLY SOME PUBLIC INCONVIENCE.
B. MODERATE FLOODING - THE INUNDATION OF SECONDARY ROADS; TRANSFER
TO HIGHER ELEVATION NECESSARY TO SAVE PROPERTY; SOME EVACUATION MAY
BE REQUIRED.
C. MAJOR FLOODING - A GENERAL TERM INCLUDING EXTENSIVE INUNDATION
AND PROPERTY DAMAGE (USUALLY CHARACTERIZED BY THE EVACUATION OF
PEOPLE AND LIVESTOCK AND THE CLOSURE OF BOTH PRIMARY AND SECONDARY
ROADS.
D. SNOWMELT FLOODING - FLOOD CAUSED PRIMARILY BY THE MELTING OF
SNOW. FACTORS THAT CONTRIBUTE TO FORECASTING SNOWMELT FLOODING ARE:
SOIL MOISTURE, SOIL FROST, SNOW-WATER EQUIVALENT, RIVER ICE, BASE
FLOWS, FUTURE PRECIPITATION, AND RATE OF MELT.
E. OUTLOOKS - ARE PROVIDED FOR "LONG RANGE" (WEEKS TO MONTHS)
PROJECTIONS BASED ON CLIMATOLOGICAL PATTERNS OF PRECIP AND TEMP.
F. FORECASTS - ARE PROVIDED FOR "SHORT TERM" (DAYS) PROJECTIONS
BASED ON FUTURE FORECASTED PATTERNS OF PRECIP AND TEMP.
4. CURRENT INFORMATION AND OUTLOOKS FOR SELECTED RIVER AREAS OF MSO
ST. LOUIS AOR:
A. RED RIVER OF THE NORTH - FIRST CREST ON RIVER PAST THROUGH AREA
DURING PAST 30 DAY PERIOD DUE TO EARLY SNOWMELT. RIVER LEVEL REACHED
FLOOD STAGE OR SLIGHTLY ABOVE ALONG SEVERAL LOCATIONS BWTN WAHPETON,
ND AND PEMBINA, ND. THE RIVER AND TRIBUTARIES CONTAIN A SIGNIFICANT
AMOUNT OF ICE. MOST OF THE SNOW REMAINS IN THE CENTRAL PORTION OF
NORTH DAKOTA WHICH FEEDS THE PEMBINA RIVER (SEE PARA 4.B), A
TRIBUTARY TO THE RED RIVER OF THE NORTH. OUTLOOK FOR THE RED RIVER
OF THE NORTH IS FOR MINOR SNOWMELT FLOODING, WITH THE EXCEPTION OF
THE CONFLUENCE OF THESE TWO RIVERS, WHICH MAY SEE MODERATE FLOODING.
B. PEMBINA RIVER BASIN (MANITOBA, CANADA & NORTH DAKOTA) - CURRENTLY
THE HEAVIEST SNOW COVER REMAINS IN THIS BASIN, IN PARTICULARLY, ON
THE CANADIAN PORTION OF THE BASIN AND CENTRAL ND. A SIGNIFICANT
AMOUNT OF ICE ALSO REMAINS IN THE PEMBINA RIVER. OUTLOOK FOR THIS
AREA FROM WALHALA, ND TO NECHE, ND IS FOR MODERATE TO MAJOR FLOODING.
ND EMA IS FOCUSING ATTENTION ON NECHE, ND AS THE MOST CRITICAL IMPACT
AREA DUE TO SNOWMELT FLOODING AS PER DISCUSSIONS IN REF B. THE
OUTLOOK CALLS FOR THE RIVER AT WALHALLA TO RISE TO 15 (FLOOD STAGE IS
11 FEET). THE FLOOD OF RECORD LEVEL IS 16.2 FEET. THE RIVER AT
NECHE IS FORECASTED TO RISE TO 24 FEET. FLOOD OF RECORD IS 24.5 FEET
IN 1997. ND EMA EXPECTS FIRST CREST THRU THIS AREA NEXT WEEK.
SECONDARY CREST IS EXPECTED WHEN SNOWMELT BECOMES MORE PROGRESSIVE.
C. DEVILS LAKE BASIN, NORTH DAKOTA. THE PRESENT LAKE LEVEL IS
1442.9 FT ABOVE MSL. THE LAKE LEVEL IS STILL FORECASTED TO REACH
NEAR 1445 BY JUNE OR JULY. THE HIGHEST LEVEL ON RECORD WAS JULY 1997
AT 1443.0 FT ABOVE MSL. THE FOLLOWING IS THE FORECASTED CREST
OUTLOOK:
1445.0 - 1445.5: BASED ON NORMAL PRECIP & EVAP FM 3/13 - 7/15
BELOW 1445.0: IF PRECIP IS BELOW NORMAL
ABOVE 1444.5: IF PRECIP IS ABOVE NORMAL, EVAP IS BELOW NORM
OUTLOOK BASED ON ABOVE INFO IS FOR MODERATE TO MAJOR FLOODING ALONG
PERIMETER OF LAKE. ND EMA HAS CONTINGENCY PLAN DEVELOPED TO DEAL
WITH THIS ISSUE. THIS HAS BEEN AN ON-GOING PROBLEM FOR MANY YEARS.
D. UPPER MISSISSIPPI RIVER (UMR) BASIN. THE RIVER LEVEL HAS REACHED
HIGH WATER MARKS AT SEVERAL LOCATIONS DUE TO RECENT RAINFALL AND SOME
SNOWMELT IN NORTHERN PORTION OF BASIN. FLOOD STAGE LEVELS HAVE BEEN
REACHED AT SPECIFIC LOCATIONS BUT ARE IN A DOWNWARD TREND. COMMERCIAL
NAVIGATION ON THE UMR BEGAN IN EARLY MARCH, MUCH EARLIER THAN NORMAL.
OUTLOOK FOR THE UMR DOWN TO CHESTER, IL AND ITS TRIBUTARIES IS FOR
VERY MINOR OR NO SNOWMELT FLOODING.
E. MISSOURI AND JAMES RIVER BASINS. CURRENT CONDITIONS ARE BELOW
FLOOD STAGE. NEAR FLOOD STAGE CONDITIONS WERE OBSERVED AT SOME
LOCATIONS DUE TO RECENT RAINFALL, BUT ARE IN A DOWNWARD TREND AGAIN.
THE BLACK HILLS OF SOUTH DAKOTA CURRENLY HAS THE MOST SIGNIFICANT
SNOWPACK FOR THIS BASIN, WITH UP TO 110 PERCENT OF NORMAL. THE
MELTING PATTERN OF THIS SNOW IS NOT EXPECTED TO CAUSE PROBLEMS ON THE
MISSOURI RIVER. THE UPPER MOR IS STILL FROZEN. COMMERCIAL
NAVIGATION ON THE MOR WILL BE OPEN FM SIOUX CITY DOWN TO THE MOUTH BY
APRIL 1. IT IS EXPECTED THAT THE MOR WILL HAVE A NORMAL RIVER LEVEL
SEASON.
F. SOURIS RIVER BASIN, NORTH DAKOTA. THE SOURIS RIVER AND
TRIBUTARIES ARE PRESENTLY BELOW FLOOD STAGE FROM SHERWOOD, ND TO
VELVA, ND. OUTLOOK: THE SNOWMELT FLOOD OUTLOOK IS FOR CRESTS BELOW
FLOOD STAGE.
G. MINNESOTA RIVER, MINNESOTA. CURRENT CONDITIONS ARE BELOW FLOOD
STAGE. RIVER ICE IS NON-EXISTENT OR WELL BELOW NORMAL FOR THIS TIME
OF YEAR. THE OUTLOOK IS FOR MINOR OR NO SNOWMELT FLOODING.
H. ILLINOIS RIVER, ILLINOIS. THE RIVER LEVELS HAVE BEEN AT FLOOD
STAGE OR A FEW FEET ABOVE FLOOD STAGE DUE TO RECENT RAIN & SNOW, AND
CURRENT WARMING TREND WITH SOME SNOWMELT. THE RIVER IS CRESTING AND
BEGINNING A SLOW DOWNWARD TREND. SEVERAL OF THE TRIBUTARIES TO THE
ILLINOIS RIVER ARE STILL WELL ABOVE FLOOD STAGE. OUTLOOK: THE
POTENTIAL FOR FLOODING HAS INCREASED AS A RESULT OF THE RECENT
SNOWSTORM IN THE LAST TWO WEEKS. THE SNOWMELT FLOOD OUTLOOK IS FOR
MINOR TO MODERATE FLOODING ALONG THE UPPER ILLINOIS RIVER ABOVE
LASALLE, IL. THE REMAINDER OF THE ILLINOIS IS FOR MINOR OR NO
SNOWMELT FLOODING.
5. ALL OF THE FORECASTS ABOVE ARE BASED ON NORMAL CLIMATIC TRENDS
THROUGH THE NEXT TWO WEEKS. ANY RAINFALL ABOVE THE NORMAL TRENDS
WILL CHANGE THE FLOOD OUTLOOKS.
6. MSO ST. LOUIS FLOOD PUNTS ARE IN RFI STATUS. PRE-DESIGNATED
DRUS IDENTIFIED. ONLY AREA OF PARTICULAR CONCERN IS DEVEL'S LAKE AND
THE PEMBINA RIVER BASIN. REGULAR COMMS WITH NORTH DAKOTA EMA WILL
CONTINUE UNTIL SPRING FLOOD THREATS HAVE PASSED. DISCUSSIONS WITH ND
EMA OPS PER REF B, INDICATE NO CG ASSISTANCE OR RESOURCES WILL BE
NEEDED. THIS IS ALL CONTINGENT ON CURRENT WEATHER TRENDS AND CURRENT
FORECASTED FLOOD CONDITIONS.
7. AN EXCELLENT WEBSITE FOR DAILY NWS NATIONAL FLOOD SUMMARY UPDATES IS "HTTP://WWW.NWS.NOAA.GOV/OH/HIC/CURRENT/FLN/FLN_SUM.HTML" (ALL IN
LOWER CASE LETTERS).
8. NEXT SITREP WILL BE SENT OUT BY 10 APRIL 98. UNIT POC IS CWO3
BOB HILDEBRAND AT (314) 539-3091, EXT. 225.
BT