DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BISMARCK ND
1025 AM CDT THU SEPT 25 2008
...DROUGHT CONDITIONS HAVE BEEN DOWNGRADED TO SEVERE FOR PARTS OF
WESTERN 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. SPRING
MOISTURE WAS SPARSE IN THIS AREA ALSO CONTRIBUTING TO THE DROUGHT.
BUT RECENT RAINFALL IN THE SUMMER AND ESPECIALLY IN SEPTEMBER HAS
HELPED ALLEVIATE DROUGHT CONDITIONS TO ONLY SEVERE STATUS INSTEAD OF
EXTREME.
CURRENT SYNOPSIS...
SEPTEMBER RAINFALL FOR BISMARCK HAS BEEN 1.10 INCHES ABOVE NORMAL
THUS FAR WITH JAMESTOWN ALSO 1.49 INCHES ABOVE NORMAL. MINOT HAS
BEEN SLIGHTLY ABOVE NORMAL WITH 0.21 INCHES OVER THE NORM FOR THE
MONTH WITH WILLISTON AT 0.49 INCHES ABOVE NORMAL. ONLY DICKINSON
REMAINED BELOW NORMAL FOR THE MONTH WITH 0.76 INCHES BELOW THE NORM
FOR SEPTEMBER.
JANUARY 2008 THROUGH SEPTEMBER SO FAR...MOISTURE WAS JUST SLIGHTLY
BELOW NORMAL FOR MINOT AND NEARLY AN INCH BELOW NORMAL FOR BISMARCK.
DICKINSON AND WILLISTON REMAINED WELL BELOW NORMAL...WITH DICKINSON
THE DRIEST. JAMESTOWN WAS THE ONLY SITE WITH SLIGHTLY ABOVE NORMAL
MOISTURE. SEE TABLE BELOW.
2008 PRECIPITATION...JANUARY THROUGH SEPTEMBER 24TH
LOCATION PRECIP SINCE DEPARTURE FROM
JAN 1, 2008 NORMAL
BISMARCK 13.32 -0.85
WILLISTON 8.30 -3.57
MINOT 15.11 -0.27
JAMESTOWN 16.04 0.35
DICKINSON 7.75 -6.08
ACCORDING TO THE LONG-TERM DROUGHT MONITOR...SEVERE DROUGHT
CONDITIONS (D2) CONTINUE FOR MAINLY SOUTHWESTERN NORTH DAKOTA. THE
NORTHWEST AND CENTRAL COUNTIES ARE IN A MODERATE TO ABNORMALLY DRY
DROUGHT STATUS. THE EAST WAS OUT OF THE ABNORMALLY DRY STATUS. THE
LATEST DROUGHT CONDITIONS SEEMED TO HAVE DIMINISHED SOMEWHAT IN
WESTERN AND CENTRAL NORTH DAKOTA DUE TO RECENT RAINFALL IN SEPTEMBER
WHICH IS GOOD NEWS.
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 SEVERE DROUGHT FOR THE WEST CENTRAL CLIMATE
DIVISION OF NORTH DAKOTA. A PORTION OF CENTRAL NORTH DAKOTA IS IN A
MILD DROUGHT. THE EASTERN THIRD IS OUT OF THE 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 3-6 INCHES.
THE SEASONAL DROUGHT OUTLOOK WHICH WAS RELEASED IN LATE SEPTEMBER
SHOWS THE DROUGHT CONDITIONS EXPECTED TO CONTINUE NEAR THE MONTANA
BORDER AND IMPROVES AS ONE MOVES TO THE EASTERN PART OF THE STATE.
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/predictions/threats2/enso/elnino/index.shtml
PRECIPITATION/TEMPERATURE OUTLOOKS...
THE LATEST 30 DAY OUTLOOK CALLS FOR EQUAL CHANCES FOR NEAR NORMAL
TEMPERATURE AND PRECIPITATION THROUGH OCTOBER. THE LATEST 90 DAY
OUTLOOK VALID THROUGH DECEMBER CALLS FOR SLIGHTLY ABOVE NORMAL
TEMPERATURES AND EQUAL CHANCES FOR NEAR NORMAL 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