National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS25 KWNC 231230
PMDDRO
US DROUGHT MONITOR DISCUSSION
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EST THU 23 MAY 2013

NATIONAL DROUGHT SUMMARY  MAY 21, 2013 WEATHER SUMMARY:  FOR
SEVERAL DAYS IN MID MAY, CORN PLANTING AND OTHER MIDWESTERN
FIELDWORK ACCELERATED IN ADVANCE OF A DEVELOPING STORM.
PRODUCERS PLANTED 43 PERCENT OF THE U.S. CORN CROP DURING
THE WEEK ENDING MAY 19, TYING A WEEKLY RECORD SET FROM MAY
4 10, 1992.  HOWEVER, HEAVY RAIN EVENTUALLY OVERSPREAD THE
NORTHERN PLAINS AND MIDWEST, HALTING PLANTING PROGRESS BUT
PROVIDING FURTHER DROUGHT RELIEF OR ERADICATION.  THE SAME STORM
RESPONSIBLE FOR THE RAIN IN THE NORTH CENTRAL U.S. CONTRIBUTED
TO A MULTI DAY SEVERE WEATHER OUTBREAK.  IOWAS LONGEST STRETCH
WITHOUT A TORNADO /359 DAYS FROM MAY 25, 2012, TO MAY 18, 2013/
ENDED WHEN SEVERAL TWISTERS WERE SPOTTED ON MAY 19.  PREVIOUSLY,
IOWAS LONGEST SPELL OF TORNADO FREE WEATHER LASTED 355 DAYS
IN 1955 56.  ONE DAY AFTER IOWAS TORNADOES, TRAGEDY STRUCK
MOORE, OKLAHOMA, ON MAY 20 IN THE FORM OF A DEVASTATING EF 5
TWISTERTHE NATIONS FIRST CATEGORY FIVE EVENT SINCE A SIMILARLY
POWERFUL TORNADO STRUCK EL RENO, OKLAHOMA, ON MAY 24, 2011.
SEVERAL DAYS OF WARMTH PRECEDED THE STORM ACROSS THE WESTERN
AND CENTRAL U.S.  ON MAY 14, A PHENOMENAL SURGE OF HEAT REACHED
THE CENTRAL PLAINS AND WESTERN CORN BELT, RESULTING IN SEVERAL
MONTHLY RECORD HIGHS AND WIDESPREAD READINGS ABOVE 100F.
LATER, TRIPLE DIGIT HEAT DEVELOPED AND PERSISTED IN THE
SOUTH CENTRAL U.S.  IN ADDITION, RAINFALL LARGELY BYPASSED
THE SOUTHERN HIGH PLAINS, RESULTING IN FURTHER DETERIORATION
IN THE CONDITION OF RANGELAND, PASTURES, AND WINTER WHEAT.
HOT, MOSTLY DRY WEATHER ALSO PREVAILED FROM CALIFORNIA INTO
THE SOUTHWEST.  FARTHER NORTH, HOWEVER, SCATTERED SHOWERS
PROVIDED BENEFICIAL MOISTURE FOR CROPS AND PASTURES IN
THE NORTHWEST.  MORE SIGNIFICANT PRECIPITATION DAMPENED THE
NORTHERN INTERMOUNTAIN WEST, PARTICULARLY ACROSS PORTIONS OF
WYOMING AND SOUTHERN MONTANA.  THE EAST:  VARYING AMOUNTS OF
RAIN FELL ACROSS THE EAST DURING THE DROUGHT MONITORING PERIOD.
LITTLE OR NO RAIN FELL IN THE NORTHEASTERN AREAS OF DRYNESS
/D0/ AND MODERATE DROUGHT /D1/, EXCEPT IN NORTHERN NEW ENGLAND.
AS A RESULT, PREVIOUSLY EXISTING AREAS OF DRYNESS WERE BRIDGED
ACROSS PENNSYLVANIA AND NEW YORK.  IN NEW ENGLAND, MARCH 1
MAY 21 PRECIPITATION TOTALED LESS THAN 6 INCHES IN LOCATIONS
SUCH AS PORTLAND, MAINE /5.85 INCHES, OR 52 PERCENT OF NORMAL/,
AND PROVIDENCE, RHODE ISLAND /5.83 INCHES, OR 50 PERCENT/.
FARTHER SOUTH, SCATTERED SHOWERS AND THUNDERSTORMS BROUGHT
LOCALIZED RELIEF FROM DRYNESS TO THE CENTRAL APPALACHIANS
AND THE EASTERN CAROLINAS.  MEANWHILE, SHORT TERM RAINFALL
DEFICITS ALLOWED FOR SOME DEVELOPMENT OF ABNORMAL DRYNESS IN
SOUTHERN ALABAMA AND WESTERN FLORIDA.  IN DOTHAN, ALABAMA,
MARCH 1  MAY 21 RAINFALL TOTALED JUST 5.56 INCHES /49 PERCENT
OF NORMAL/.  THE UPPER MIDWEST:  PRIOR TO THE ARRIVAL OF WET
WEATHER, SHARP TEMPERATURE FLUCTUATIONS WERE NOTED IN THE
UPPER MIDWEST.  FOLLOWING A LATE SEASON FREEZE ON MAY 12,
TEMPERATURES BRIEFLY SOARED.  TEKAMAH, NEBRASKA, EXPERIENCED
A HIGH OF 108F ON MAY 14, ECLIPSING ITS MONTHLY RECORD OF
105F ORIGINALLY SET ON MAY 31, 1934.  A MONTHLY RECORD FROM
THE DUST BOWL ERA /105F ON MAY 30, 1934/ WAS ALSO BROKEN
IN SIOUX CITY, IOWA, WHERE THE MAY 14 HIGH SOARED TO 106F.
IN FACT, THERE HAD NEVER BEEN A READING OF 105F OR GREATER IN
IOWA BEFORE MAY 29... SAC CITY HAD ACHIEVED A HIGH OF 108F ON
MAY 29, 1934.  IN NEBRASKA, RECORDS FOR THE EARLIEST TRIPLE
DIGIT HEAT WERE SET ON MAY 14 IN LOCATIONS SUCH AS GRAND
ISLAND /102F/, OMAHA /101F/, AND LINCOLN /100F/... GRAND
ISLANDS RECORD HAD STOOD SINCE MAY 20, 1925.  SEVERAL DAYS
LATER, SHOWERS AND THUNDERSTORMS ENGULFED THE UPPER MIDWEST,
LEADING TO SIGNIFICANT REDUCTIONS IN THE COVERAGE AND INTENSITY
OF ANY LINGERING DROUGHT.  SOME OF THE HEAVIEST RAIN FELL IN
MINNESOTA, AS WELL AS NEIGHBORING AREAS IN NORTHERN IOWA AND
NORTHWESTERN WISCONSIN.  ROCHESTER, MINNESOTA, IN A PART OF THE
STATE NO LONGER CATEGORIZED AS ABNORMALLY DRY, SET RECORDS FOR
MAY /8.55 INCHES/ AND MARCH MAY PRECIPITATION /18.19 INCHES/.
ROCHESTERS PREVIOUS RECORDS HAD BEEN 8.41 INCHES IN 1982 AND
15.87 INCHES IN 2001, RESPECTIVELY.  WITH A TOTAL OF 2.43
INCHES OF RAIN ON MAY 17, ROCHESTER EXPERIENCED ITS THIRD
WETTEST DAY IN MAY, BEHIND 4.02 INCHES ON MAY 17, 2000, AND
2.97 INCHES ON MAY 20, 1912.  THE GREAT PLAINS:  THE GRADIENT
BETWEEN IMPROVING CONDITIONS AND WORSENING DROUGHT CONTINUED
TO SHARPEN.  A WINTER LIKE STORM DELIVERED WIDESPREAD, HEAVY
PRECIPITATION /LOCALLY 4 INCHES OR MORE/ TO THE NORTH CENTRAL
U.S., INCLUDING THE DAKOTAS AND PARTS OF MONTANA AND NEBRASKA.
SIGNIFICANT RAIN ALSO FELL ACROSS THE SOUTHEASTERN PLAINS,
INCLUDING CENTRAL AND EASTERN OKLAHOMA AND NORTHEASTERN TEXAS.
IN CONTRAST, LITTLE OR NO PRECIPITATION FELL ACROSS THE SOUTHERN
HIGH PLAINS.  AS A RESULT, THERE WERE MAJOR REDUCTIONS IN
DROUGHT COVERAGE AND INTENSITY ON THE NORTHERN AND SOUTHEASTERN
PLAINS, BUT AN INCREASE IN THE AREAL COVERAGE OF EXCEPTIONAL
DROUGHT /D4/ AND OTHER DROUGHT CATEGORIES ON THE SOUTHERN
HIGH PLAINS.  IN TEXAS, THE PORTION OF THE WINTER WHEAT RATED
VERY POOR TO POOR INCREASED FROM 44 TO 76 PERCENT BETWEEN
MARCH 17 AND MAY 19, ACCORDING TO USDA.  ALTHOUGH SOME OF
THE WINTER WHEAT DETERIORATION WAS DUE TO DROUGHT, A SERIES
OF SPRING FREEZES ALSO HARMED THE CROP.  MEANWHILE, AT LEAST
ONE THIRD OF THE RANGELAND AND PASTURES WERE RATED VERY POOR
TO POOR BY MAY 19 IN EVERY PLAINS STATE EXCEPT NORTH DAKOTA.
LINGERING DISMAL PASTURE CONDITIONS IN STATES SUCH AS NEBRASKA
/69 PERCENT VERY POOR TO POOR/ AND SOUTH DAKOTA /51 PERCENT/
ARE DUE TO THE HARM INFLICTED BY THE HISTORIC 2012 DROUGHT,
IN COMBINATION WITH A COOL SPRING THAT DELAYED GREENING OF
GRASSES.  THE WEST:  SUBSTANTIAL PRECIPITATION FELL DURING
THE MONITORING PERIOD ACROSS THE NORTHERN INTERMOUNTAIN WEST.
WIDESPREAD TOTALS IN EXCESS OF 2 INCHES WERE NOTED IN WYOMING
AND SOUTHERN MONTANA, WHILE 1  TO 2 INCH TOTALS WERE REPORTED
IN PARTS OF NORTHERN UTAH AND EASTERN IDAHO.  AS A RESULT,
THERE WERE REDUCTIONS IN THE INTENSITY OF MODERATE TO
EXTREME DROUGHT /D1 TO D3/ IN SOME OF THE WETTEST AREAS.
HOWEVER, THE STORM RESPONSIBLE FOR THE HEAVY PRECIPITATION
DID NOT APPRECIABLY CHANGE SPRING AND SUMMER RUNOFF FORECASTS,
LEAVING VARYING DEGREES OF LONG TERM DROUGHT LARGELY INTACT.
FARTHER SOUTH, DRY WEATHER LED TO LITTLE OR NO CHANGE IN THE
DROUGHT DEPICTION.  ON MAY 19, USDA REPORTED THAT AT LEAST 40
PERCENT OF THE RANGELAND AND PASTURES WERE RATED VERY POOR TO
POOR IN SEVEN OF THE ELEVEN WESTERN STATES.  NEW MEXICO TOPPED
THE LIST, WITH 98 PERCENT OF ITS RANGELAND AND PASTURES RATED
VERY POOR TO POOR, FOLLOWED BY NEVADA /69 PERCENT/, ARIZONA
/63 PERCENT/, COLORADO /48 PERCENT/, MONTANA /47 PERCENT/,
WYOMING /46 PERCENT/, AND CALIFORNIA /40 PERCENT/.  IN ADDITION,
BELOW AVERAGE STATEWIDE RESERVOIR STORAGE AFFECTED FIVE WESTERN
STATES:  ARIZONA, COLORADO, NEVADA, NEW MEXICO, AND OREGON.
NEAR AVERAGE OVERALL STORAGE SHOULD SERVE AS A BUFFER AGAINST
DROUGHT IN THE OTHER WESTERN STATES /CALIFORNIA, IDAHO, MONTANA,
UTAH, AND WYOMING/, EXCEPT WASHINGTON, WHERE RESERVOIR STORAGE
WAS ABOVE AVERAGE AND THERE WAS NO DROUGHT.  HAWAII, ALASKA
AND PUERTO RICO:  THERE WERE NO CHANGES TO THE DEPICTIONS FOR
HAWAII, ALASKA, AND PUERTO RICO.  HAWAIIS WESTERN ISLANDS
/OAHU WESTWARD/ REMAIN FREE OF DRYNESS AND DROUGHT.  HOWEVER,
ISLANDS FROM MAUI EASTWARD ARE STILL EXPERIENCING SIGNIFICANT
DROUGHT IN LEEWARD AREAS.  USDA REPORTED THAT RECENT RAINFALL IN
WINDWARD AND MOUNTAIN SECTIONS OF MAUI ALLOWED FOR IMPROVEMENT
OF PASTURE CONDITIONS IN MOST AREAS.  THE SAME REPORT INDICATED
THAT SOUTHERN SECTIONS OF MAUI AND MOLOKAI HAD RECEIVED
SOME RECENT RAIN, BUT THAT THOSE AREAS HAD PREVIOUSLY DRIED
OUT, WITH NO GREEN FORAGE FOR SEVERAL MONTHS.  MEANWHILE,
ALASKA WAS LOCKED INTO AN UNUSUALLY COLD WEATHER PATTERN, WITH
LITTLE PRECIPITATION REPORTED IN EXISTING AREAS OF ABNORMAL
DRYNESS /D0/ AND MODERATE DROUGHT /D1/.  AND, LIKE LAST WEEK,
THERE WAS NO DROUGHT /OR DRYNESS/ IN DEPICTED IN PUERTO RICO.
LOOKING AHEAD:  DURING THE NEXT 5 DAYS /MAY 23 27/, THE SLOW
MOVING STORM SYSTEM THAT HAS BEEN AFFECTING THE MIDWESTAND
WAS RESPONSIBLE FOR THE TRAGIC TORNADO IN MOORE, OKLAHOMAWILL
DRIFT EASTWARD.  THE SYSTEM WILL REACH THE ATLANTIC SEABOARD
BY MAY 24.  ADDITIONAL RAINFALL TOTALSIN THE FORM OF LOCALLY
SEVERE THUNDERSTORMSCOULD REACH 1 TO 3 INCHES IN THE NORTHEAST,
AND COOL AIR WILL TRAIL THE STORM INTO THE MIDWEST AND EAST.
MEANWHILE, AN EARLY SEASON HEAT WAVE WILL DEVELOP ON THE
HIGH PLAINS.  DURING THE MEMORIAL DAY WEEKEND /MAY 25 27/,
TEMPERATURES WILL APPROACH OR REACH 100F AS FAR NORTH AS THE
CENTRAL HIGH PLAINS.  ELSEWHERE, COOL, SHOWERY WEATHER WILL
PERSIST IN THE NORTHWEST, WHILE THUNDERSHOWERS WILL RETURN TO
THE PLAINS.  MORE SUBSTANTIAL RAIN /POSSIBLY 1 TO 3 INCHES/
MAY DEVELOP DURING THE MEMORIAL DAY WEEKEND IN THE WESTERN
CORN BELT, INCLUDING PARTS OF IOWA AND EASTERN NEBRASKA.
THE NWS 6  TO 10 DAY OUTLOOK FOR MAY 28  JUNE 1 CALLS FOR
ABOVE NORMAL TEMPERATURES FROM THE PLAINS TO THE EAST COAST,
WHILE COOLER THAN NORMAL CONDITIONS WILL PREVAIL IN THE WEST.
MEANWHILE, BELOW NORMAL RAINFALL ACROSS MOST OF THE SOUTHERN
HALF OF THE U.S. WILL CONTRAST WITH WETTER THAN NORMAL WEATHER
ACROSS THE NATIONS NORTHERN TIER FROM THE PACIFIC NORTHWEST TO
THE GREAT LAKES REGION.  AUTHOR:  BRAD RIPPEY, U.S. DEPARTMENT
OF AGRICULTURE



DROUGHT INTENSITY CATEGORIES...
D0 ABNORMALLY DRY...
D1 MODERATE DROUGHT...
D2 SEVERE DROUGHT...
D3 EXTREME DROUGHT...
D4 EXCEPTIONAL DROUGHT

DROUGHT TYPES...
USED ONLY WHEN IMPACTS DIFFER...
S SHORT TERM...
L LONG TERM.


$$