FXUS25 KWNC 041748
PMDDRO
US DROUGHT MONITOR DISCUSSION
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
830 AM EST THU 04 FEB 2010
NATIONAL DROUGHT SUMMARY FEBRUARY 2, 2010 THE DISCUSSION
IN THE LOOKING AHEAD SECTION IS SIMPLY A DESCRIPTION OF WHAT
THE OFFICIAL NATIONAL GUIDANCE FROM THE NATIONAL WEATHER
SERVICE /NWS/ NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION
IS DEPICTING FOR CURRENT AREAS OF DRYNESS AND DROUGHT. THE
NWS FORECAST PRODUCTS UTILIZED INCLUDE THE HPC 5-DAY QPF
AND 5-DAY MEAN TEMPERATURE PROGS, THE 6-10 DAY OUTLOOKS
OF TEMPERATURE AND PRECIPITATION PROBABILITY, AND THE 8-14
DAY OUTLOOKS OF TEMPERATURE AND PRECIPITATION PROBABILITY,
VALID AS OF LATE WEDNESDAY AFTERNOON OF THE USDM RELEASE
WEEK. THE NWS FORECAST WEB PAGE USED FOR THIS SECTION IS:
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/FORECASTS/. THE PAST
WEEK CAN BE SUMMARIZED BY NOTING THE ACTIVE STORM TRACK ALONG
THE SOUTHERN CONTIGUOUS UNITED STATES. A STORM SYSTEM THAT
WAS IMPACTED THE DESERT SOUTH WEST AT THE START OF THE WEEK
DEVELOPED INTO A VIGOROUS LOW-PRESSURE SYSTEM ACROSS THE
SOUTHERN PLAINS BY WEEKS END. HEAVY PRECIPITATION FELL FROM
TEXAS TO THE MID-ATLANTIC WITH WIDESPREAD DAMAGE FROM WINTRY
PRECIPITATION FELT AS FAR SOUTH AS TEXAS. LIGHT PRECIPITATION
FROM WEAK IMPULSES MOVING ONSHORE ACROSS THE PACIFIC NORTHWEST
BROUGHT RAIN TO THE COASTAL REGIONS BUT BELOW-AVERAGE
PRECIPITATION TO THE INTERIOR PORTIONS OF THE INTERMOUNTAIN
WEST AND SIERRA NEVADA RANGE. BY MONTH, ANOTHER IMPULSE IN
THE SOUTHERN STREAM LINKED UP WITH ONE OF THE WEAK IMPULSES
MOVING ACROSS THE NORTHERN ROCKIES. AS THEY MOVED EASTWARD,
THE SYSTEMS PRODUCED PRECIPITATION AS SNOW FROM CHICAGO TO THE
MID-ATLANTIC AND HEAVY RAINS DOWN INTO FLORIDA. THE SOUTHWEST:
MOST OF THE CHANGES TO THE DEPICTION WERE MADE IN THE SOUTHWEST.
AS A RESULT OF A REASSESSMENT OF THE AREA OF EXTREME DROUGHT
/D3/ IN NORTHEAST ARIZONA, THIS AREA WAS REMOVED. STANDARDIZED
PRECIPITATION INDEX /SPI/ CHARTS GENERATED BY THE HIGH PLAINS
REGIONAL CLIMATE CENTER /HPRCC/ FOR 30-DAYS BACK THROUGH 6
MONTHS INDICATE THAT THE WORST CONDITIONS ARE REPRESENTATIVE
OF SEVERE DROUGHT /D2/ CONDITIONS. ADDITIONALLY, NATIONAL
CENTERS FOR ENVIRONMENTAL PREDICTION-NORTH AMERICAN LAND
DATA ASSIMILATION SYSTEM /NCEP-NLDAS/ ENSEMBLE SOIL MOISTURE
VALUES SHOW CONDITIONS RANGING BETWEEN D0 /ANOMALOUS DRYNESS/
AND D1 /MODERATE DROUGHT/, WHILE THE OBJECTIVE BLENDS ALSO SHOW
COMPLETE RELIEF OF THE DROUGHT. ACCORDING TO PRELIMINARY PRISM
RAINFALL ESTIMATES FOR THE MONTH OF JANUARY, RAINFALL TOTALS
WERE AT LEAST 150 PERCENT OF NORMAL FOR MOST OF THE STATE.
THE AREAS WITH RAINFALL TOTALS RANGING FROM NEAR NORMAL TO
130 PERCENT OF NORMAL ARE WHERE EXTREME DROUGHT CONDITIONS
ARE RETAINED. SNOWPACK VALUES ACROSS NAVAJO, APACHE, AND
NORTHERN COCONINO COUNTIES IN ARIZONA ARE WELL ABOVE NORMAL,
RANGING FROM 130 TO GREATER THAN 180 PERCENT OF NORMAL/.
ACROSS SOUTHEASTERN ARIZONA, WIDESPREAD RAINS /0.5-1.5 INCHES/
ALLOWED FOR SOME TRIMMING OF THE MODERATE DROUGHT COVERAGE
ACROSS PIMA, PINAL, GRAHAM, AND COCHISE COUNTIES. THE AREAS
IMPROVEMENT THAT RESULTED IN THE REMOVAL OF ALL DROUGHT
INDICATIONS INCLUDED SOUTHWEST NEW MEXICO AND GREENLEE COUNTY,
ARIZONA, WHERE RAINS APPROXIMATELY 1.0 INCH FELL DURING THE
PERIOD. ADDITIONAL IMPROVEMENTS WERE MADE ACROSS SOUTHERN AND
CENTRAL NEW MEXICO. MOUNTAIN SNOWPACK MEASUREMENTS INDICATE
THAT MUCH OF THE AREA HAS SNOWPACK WELL ABOVE NORMAL /180
PERCENT OF NORMAL/. REPORTS INDICATE RECORD HIGH SNOW-WATER
EQUIVALENT /SWE/ VALUES OF 225 PERCENT AT THE SIERRA BLANCA
SNOTEL SITE. ABNORMAL DRYNESS WAS ALSO REMOVED FROM LA PAZ
COUNTY IN SOUTHWESTERN ARIZONA TO HAVE THE DEPICTION IN THE
U.S. DROUGHT MONITOR REFLECT 30-, 60, 90-DAY, 12-MONTH SPI
CHARTS /ALL POSITIVE WHICH INDICATED WETNESS/, SOIL MOISTURE
VALUES FROM NCEP /70TH-80TH PERCENTILE/AND 14-DAY PERCENT OF
NORMAL PRECIPITATION TOTALS /400-800 PERCENT OF NORMAL/ THE
NORTHERN ROCKIES AND NORTHWEST: A REASSESSMENT OF THE DEPICTION
ACROSS NORTH-CENTRAL WASHINGTON RESULTED IN A DECREASE IN THE
SPATIAL EXTENT OF THE AREA OF SEVERE DROUGHT CONDITIONS AND A
SOUTHWARD SHIFT OF THE AREA. THE NEW AREA BETTER ALIGNS WITH
THE AREAS OF BELOW NORMAL PRECIPITATION STARTING 12 MONTHS AGO.
THE NORTHERN EDGE OF THE PREVIOUSLY INDICATED AREA HAD RECEIVED
ABOVE-NORMAL RAINFALL FOR THE 2009-2010 WATER YEAR. OMAK,
WA REPORTED 5.91 INCHES COMPARED TO A NORMAL OF 5.27 INCHES
FOR THE CURRENT WATER YEAR. THE REPORTED RAINFALL AT OMAK
WAS 66 PERCENT OF NORMAL FOR ALL OF 2009, SO THE WETNESS IS
A RATHER RECENT CHANGE. ACROSS DOUGLAS AND CHELAN COUNTIES,
LIMITED PRECIPITATION AND WARMER TEMPERATURES HAVE AIDED FIELD
WORK, BUT DONE NOTHING TO ALLEVIATE THE DROUGHT CONDITIONS.
IN MONTANA, A CONTINUED LACK OF MAJOR PRECIPITATION /0.25 INCH
OR LESS FOR MOST OF MONTANA/ RESULTED IN SOME IMPROVEMENTS
AND SOME DEGRADATION. THE AREA OF ABNORMAL DRYNESS WAS
EXPANDED IN WESTERN MONTANA WHERE SNOWPACK RANGED FROM 25-69
PERCENT OF NORMAL AND SPI VALUES INDICATED D0-D1 CONDITIONS FOR
TIMEFRAMES FROM 30 DAYS TO 12 MONTHS. DROUGHT CONDITIONS NEAR
BLAINE COUNTY HAVE BEEN PERSISTENT ON THE SAME TIMESCALES.
NEAR NORMAL STREAM FLOWS, AS REPORTED BY THE UNITED STATES
GEOLOGICAL SURVEY, ARE MITIGATING THE EXPANSION OF DROUGHT
CONDITIONS. MOST OF WYOMING AND NORTHERN COLORADO APPEAR
TO THE SOME OF DRIEST LOCATIONS ACROSS THE CONTIGUOUS 48
STATES WHEN CONSIDERING PERCENT OF NORMAL PRECIPITATION FOR
THE PAST 6 MONTHS. PRECIPITATION OVER THE PREVIOUS WEEK
WAS SCATTERED AND LIGHT, /1.0 INCH IN THE HIGH TERRAIN TO
0.0 IN THE LOW COUNTRY/ PROMPTING A FURTHER EXPANSION OF D0
ACROSS PORTIONS OF WYOMING. IN NORTHERN COLORADO, SNOWPACK
AND SNOW WATER CONTENT ARE RANGING FROM 50 TO 70 PERCENT OF
NORMAL, SO BORDERLINE FOR INCLUSION IN THE AREA OF ABNORMAL
DRYNESS. RESERVOIR STORAGE IN THESE AREAS IS VERY GOOD, SO
THAT MITIGATES THE OVERALL DEPICTION OF DROUGHT CONDITIONS.
A SMALL AREA OF IMPROVEMENT WAS MADE ACROSS SHASTA AND TEHAMA
COUNTIES IN NORTHERN CALIFORNIA. RAINFALL TOTALS OF 1.8 AND
1.4 INCHES CAME IN FROM TWO STATIONS IN THIS REGION. TEXAS:
A 1 CATEGORY IMPROVEMENT, BASED ON RAINFALL TOTALING OF 1.0 TO
2.8 INCHES, WAS MADE ACROSS SOUTHWESTERN TEXAS FROM TERRELL
COUNTY TO LASALLE COUNTY. THE CORE AREA OF THE DROUGHT
REGION WAS MAINTAINED AS SEVERE DROUGHT /D2/ BUT REDUCED
IN SIZE. JANUARY WAS THE 4TH WETTEST AT DEL RIO, TX IN A
RECORD STRETCHING OVER 100 YEARS WHILE SAN ANTONIO LOGGED
THE 10TH WETTEST JANUARY SINCE 1871. THE SEVERE DROUGHT
AREA WAS REMOVED FROM THE DROUGHT AREA NEAR CORPUS CHRISTI
IN RESPONSE TO LIGHT RAINS /0.1-0.2 INCH/, GOOD STREAM FLOW
/NEAR NORMAL IN THE AREA INDICATED AS D2 ON PERVIOUS MAPS/,
LACK OF REPORTED IMPACTS FROM DROUGHT, AND REPORTED IMPACTS
OF TOO MUCH MUD. ACROSS NORTHWESTERN TEXAS, RAINFALL RANGING
FROM 0.5 TO 1.7 INCHES PROMPTED THE REMOVAL OF MUCH OF THE AREA
OF ABNORMAL DRYNESS. TWO AND SIX-MONTH WEIGHTED SPI VALUES
FROM THE OFFICE OF THE STATE CLIMATOLOGIST OF TEXAS SUPPORTED
THE RETENTION OF D0 FROM HOWARD COUNTY TO STONEWALL COUNTY.
THE UPPER MID-WEST: NO CHANGES WERE MADE IN THIS REGION.
THE LAKE EFFECT SNOWS ARE FALLING ON FROZEN GROUND SO SOIL
MOISTURE IS NOT INCREASING BUT WATER DEMAND DURING THE WINTER
IS MINIMAL. HAWAII AND ALASKA: IN HAWAII, ANOTHER MOSTLY
DRY WEEK, EXCEPT FOR RAINS ACROSS KAUAI /1.1 TO 2.9 INCHES/
AND OAHU /0.4 TO 4.2 INCHES/. REPORTS FROM MAUI INDICATED
RAINS NEAR 0.5 INCH WHILE REPORTS ON THE BIG ISLAND SHOWED
LESS THAN A QUARTER INCH. THE CONTINUED LACK OF RAINFALL THIS
WEEK PROMPTED AN ADDITIONAL AREA OF EXTREME DROUGHT ACROSS
THE SOUTHERN GROWING AREAS OF THE BIG ISLAND. IN ALASKA,
LITTLE OR NO PRECIPITATION FELL ACROSS MUCH OF THE STATE.
REPORTS FROM NEAR THE SOUTHERN SHORE, ADJACENT ISLANDS, AND
ALONG THE PANHANDLE INDICATE PRECIPITATION AMOUNTS RANGED FROM
1.4 TO 5.1 INCHES. THE FROZEN GROUND AND DORMANT VEGETATION
PROVIDE MINIMAL DEMAND FOR GROUND WATER, SO THE DEPICTION WAS
MAINTAINED FROM LAST WEEK LOOKING AHEAD: DURING THE NEXT 5
DAYS /FEBRUARY 4-9/, AN ACTIVE SOUTHERN STORM TRACK IS EXPECTED
TO CONTINUE BRINGING WET WEATHER TO THE AREA FROM NEW MEXICO
TO THE SOUTHEAST TO THE MID-ATLANTIC. FROM THURSDAY INTO
SATURDAY, A STORM SYSTEM IS EXPECTED TO MOVE FROM TEXAS TO THE
CAROLINA COAST. PRECIPITATION TOTALS ARE EXPECTED TO BE GREATER
THAN 1.0 INCH FROM COASTAL TEXAS TO SOUTHERN NEW JERSEY, WITH
THE NORTHERN EXTENT BEING FROZEN OR FREEZING PRECIPITATION.
ANOTHER STORM SYSTEM IS EXPECTED TO MOVE ON SHORE ACROSS
NORTHERN CALIFORNIA AND OREGON FROM FRIDAY INTO SATURDAY.
MODERATE PRECIPITATION IS EXPECTED FROM THIS SYSTEM. BY NEXT
MONDAY, ANOTHER LOW-PRESSURE IS EXPECTED TO DEVELOP ACROSS
NORTHERN MEXICO AND BRING PRECIPITATION TO THE SOUTHERN PLAINS
YET AGAIN. LITTLE TO NO PRECIPITATION IS EXPECTED ACROSS THE
NORTHERN ROCKIES AND NORTHWEST, WHICH SHOULD BE MONITORED AS
EL NIO CONDITIONS TYPICALLY FAVOR DRYNESS IN THESE REGIONS.
AUTHOR: MATTHEW ROSENCRANS, NOAA/NWS/NCEP/CLIMATE PREDICTION
CENTER.
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...
A AGRICULTURAL...
H HYDROLOGIC.
$$
