DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BISMARCK ND
1010 AM CDT THU AUG 21 2008
...SEVERE TO EXTREME DROUGHT CONTINUES FOR PARTS OF NORTH DAKOTA...
THIS OUTLOOK COVERS THE BISMARCK HYDROLOGIC SERVICE AREA (HSA) WHICH
ENCOMPASSES 36 COUNTIES IN WEST AND CENTRAL NORTH DAKOTA. THE PRIMARY
RIVER BASINS ARE THE MISSOURI...JAMES...SOURIS...AND THEIR
TRIBUTARIES.
OVERVIEW...
DROUGHT CONDITIONS HAVE EXISTED FOR MUCH OF NORTH DAKOTA SINCE THE
FALL OF 2007 WHICH WAS VERY DRY. SEASONAL SNOWFALL WAS BELOW NORMAL
FOR THE WEST AND CENTRAL CREATING VERY DRY SOIL CONDITIONS. SNOWFALL
TOTALS FROM OCTOBER 2007 THROUGH MAY 2008 VARIED FROM ONLY 12 INCHES
WEST TO 20 INCHES EAST CENTRAL. THE EAST RECEIVED NORMAL AMOUNTS
AROUND 40 INCHES.
CURRENT SYNOPSIS...
JULY 2008 RAINFALL WAS SLIGHTLY BELOW NORMAL AROUND THE MAIN
REPORTING SITES. FOR AUGUST...JAMESTOWN HAS BEEN DOWN ALMOST 0.50
INCHES WITH MINOT UP ABOUT 0.75 INCHES. BISMARCK...WILLISTON AND
DICKINSON WERE SLIGHT BELOW NORMAL.
JANUARY 2008 THROUGH AUGUST SO FAR...MOISTURE WAS JUST SLIGHTLY
BELOW NORMAL FOR JAMESTOWN AND MINOT...BUT CONTINUES BELOW NORMAL
FOR BISMARCK...DICKINSON AND WILLISTON...WITH DICKINSON AND
WILLISTON THE DRIEST.
2008 PRECIPITATION...JANUARY THROUGH MID AUGUST
LOCATION PRECIP SINCE DEPARTURE FROM
JAN 1, 2008 NORMAL
BISMARCK 10.83 -1.28
WILLISTON 6.48 -3.78
MINOT 12.52 -0.71
JAMESTOWN 12.94 -0.52
DICKINSON 6.87 -5.04
ACCORDING TO THE LONG-TERM DROUGHT MONITOR...SEVERE TO EXTREME
DROUGHT CONDITIONS (D2 TO D3) CONTINUE FOR WEST CENTRAL AND
NORTHWEST NORTH DAKOTA. THE CENTRAL COUNTIES ARE IN A MODERATE TO
ABNORMALLY DRY DROUGHT STATUS. THE EAST IS IN ABNORMALLY DRY
STATUS.
THE DROUGHT MONITOR IS A LONG-TERM INDICATOR OF DROUGHT CONDITIONS.
IT IS COOPERATIVELY DETERMINED BY DROUGHT EXPERTS ASSOCIATED WITH
THE USDA...THE DROUGHT MITIGATION CENTER...AND NOAA'S CLIMATE
PREDICTION CENTER.
THE PALMER DROUGHT SEVERITY INDEX OR (PDSI) IS A MEDIUM TERM MONITOR
OF DROUGHT CONDITIONS. IT INDICATES A PROLONGED AND ABNORMAL MOISTURE
DEFICIENCY OR EXCESS. THIS PRODUCT IS UPDATED WEEKLY. NORTH DAKOTA
IS CURRENTLY RANKED EXTREME DROUGHT FOR THE WEST CENTRAL CLIMATE
DIVISION OF NORTH DAKOTA. THE PORTION OF CENTRAL NORTH DAKOTA IS IN
SEVERE TO MILD DROUGHT. THE EASTERN THIRD IS IN ABNORMALLY DRY
STATUS. THIS MONITOR TAKES INTO ACCOUNT WEEKLY TEMPERATURES
...PRECIPITATION...SOIL CAPACITIES...AND PREVIOUS HISTORY OF THE
INDICES. ADDITIONAL PRECIPITATION NEEDED TO TURN THE DROUGHT AREAS
AROUND OR TO BRING THE DROUGHT LOCATIONS BACK TO A NORMAL STATUS
WOULD REQUIRE AN AVERAGE OF 2-7 INCHES.
THE SEASONAL DROUGHT OUTLOOK WHICH WAS RELEASED IN MID AUGUST SHOWS
THE DROUGHT CONDITIONS EXPECTED TO CONTINUE NEAR THE MONTANA BORDER
AND IMPROVES AS ONE MOVES TO THE EASTERN PART OF THE STATE. THIS
OUTLOOK IS VALID UNTIL OCTOBER 2008.
THE CURRENT DROUGHT IS DUE IN PART TO THE CHANGE FROM LA NINA TO
NEUTRAL CONDITIONS. FOR MORE ON THE NEUTRAL EFFECT...REFER TO:
http://www.cpc.ncep.noaa.gov/products/precip/cslink/mjo/enso.html
PRECIPITATION/TEMPERATURE OUTLOOKS...
THE LATEST 30 DAY OUTLOOK CALLS FOR NO DEVIATION FROM NORMAL FOR
TEMPERATURE OR PRECIPITATION. THE LATEST 90 DAY OUTLOOK VALID THROUGH
OCTOBER ALSO CALLS FOR NO DEVIATION FROM NORMAL FOR TEMPERATURE OR
PRECIPITATION.
THESE LONG RANGE OUTLOOKS CAN BE VIEWED ON THE INTERNET AT:
http://www.cpc.ncep.noaa.gov/products/forecasts/
GENERAL DROUGHT DEFINITION...
DROUGHT IS WHEN A SHORTFALL IN PRECIPITATION CREATES A SHORTAGE OF
WATER...WHETHER ITS FOR CROPS...UTILITIES...MUNICIPAL WATER
SUPPLIES...RECREATION ...OR WILDLIFE.
DROUGHTS DON'T JUST HAPPEN OVERNIGHT BUT SLOWLY DEVELOP OVER A
PERIOD OF TIME. IN AN OPERATIONAL SENSE...THE THRESHOLD USUALLY USED
TO DEFINE THE BEGINNING OF THE DROUGHT IS ARBITRARY. HOWEVER A RULE
OF THUMB IS 75 PERCENT OF AVERAGE PRECIPITATION OVER A SPECIFIED
TIME PERIOD. THIS VARIES FROM REGION TO REGION BUT IS BASED ON
COMPARING THE CURRENT SITUATION TO A HISTORICAL AVERAGE...USUALLY
THE 30 YEAR AVERAGE. A DRY SPELL...BY LOOSE DEFINITION IN THE UNITED
STATES...IS A PERIOD LASTING NOT LESS THAN TWO WEEKS IN WHICH NO
MEASURABLE PRECIPITATION IS RECORDED.
THERE ARE FOUR TYPES OF DROUGHT...METEOROLOGICAL...HYDROLOGICAL...
AGRICULTURAL...AND SOCIOECONOMIC.
METEOROLOGICAL DROUGHT IS DEFINED ON THE BASIS OF THE DEGREE OF
DRYNESS IN COMPARISON TO NORMAL OR AVERAGE AND THE DURATION OF THE
DRY PERIOD. AGRICULTURAL DROUGHT LINKS HYDROLOGIC CHARACTERISTICS TO
AGRICULTURAL IMPACTS FOCUSING ON SOIL WATER DEFICITS...GROUND WATER
LEVELS...AND EVAPOTRANSPIRATION. HYDROLOGICAL DROUGHT IS ASSOCIATED
WITH PRECIPITATION SHORTFALLS ON SURFACE OR SUBSURFACE WATER SUPPLY
AND ITS SEVERITY ON A WATERSHED. SOCIOECONOMIC DROUGHT ASSOCIATES
SUPPLY AND DEMAND. IT OCCURS WHEN THE DEMAND FOR AN ECONOMIC GOOD
EXCEEDS SUPPLY AS A RESULT OF A WEATHER RELATED SHORTAGE.
PAST DROUGHTS...
THE LAST SIGNIFICANT DROUGHT FOR NORTH DAKOTA WAS FROM 1988 TO 1993.
DURING THOSE YEARS THE PALMER DROUGHT SEVERITY INDEX HAD THE STATE IN
THE MODERATE...SEVERE...AND EXTREME CATEGORIES. AN ABRUPT CHANGE
OCCURRED IN JULY OF 1993 WHEN AN UNPRECEDENTED 10-13 INCHES OF RAIN
FELL DURING THE MONTH OF JULY. BISMARCK LOGGED 13.75 INCHES OF RAIN
WITH THE YEARLY TOTAL ENDING AT 26.99 INCHES. THE DROUGHT HAD ENDED.
OTHER DROUGHT YEARS WERE 2003...2000...1998...AND 1996.
RELATED WEB SITES INCLUDE...
THE NATIONAL DROUGHT MITIGATION CENTER...
http://drought.unl.edu/
NOAA DROUGHT PAGE...
http://www.drought.noaa.gov/
US GEOLOGICAL SURVEY...
http://water.usgs.gov/
US ARMY CORPS OF ENGINEERS...
http://www.mvr.usace.army.mil/
CLIMATE PREDICTION CENTER...
http://www.cpc.ncep.noaa.gov/
NATIONAL WEATHER SERVICE-BISMARCK...
http://www.weather.gov/bis/
IF YOU HAVE ANY QUESTIONS OR COMMENTS...CONTACT THE NWS AT
701-250-4495.
JENSEN