PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300PM EDT THURSDAY JUN 30 2011

30-DAY OUTLOOK DISCUSSION FOR JULY 2011

THE UPDATED 30-DAY OUTLOOK FOR JULY 2011 IS BASED PRIMARILY ON THE LATEST 
NUMERICAL WEATHER PREDICTION (NWP) MODELS AND THE CFS (VERSION 2) MODEL. OTHER 
CONSIDERATIONS INCLUDE THE TRADITIONAL STATISTICAL TOOLS, LOCAL SEA SURFACE 
TEMPERATURES (SSTS) ALONG COASTAL AREAS, SOIL MOISTURE CONDITIONS, AND RECENT 
TEMPERATURE AND PRECIPITATION OBSERVATIONS. 

BY EARLY-MID JUNE 2011, LA NINA CONDITIONS HAD GRADUALLY GIVEN WAY TO ENSO- 
NEUTRAL CONDITIONS, ESPECIALLY IN REGARD TO THE OCEANIC COMPONENT OF THE GLOBAL 
CLIMATE SYSTEM. THE ATMOSPHERIC COMPONENT, HOWEVER, CONTINUES TO DISPLAY 
RESIDUAL EFFECTS OF THE RECENT COLD EPISODE. THE LATEST WEEKLY MEAN SST 
DEPARTURES IN THE NINO 3.4 REGION WERE 0.0 C. NEAR AVERAGE OCEAN SURFACE 
TEMPERATURES NOW DOMINATE THE CENTRAL AND EAST-CENTRAL PORTIONS OF THE 
EQUATORIAL PACIFIC, AND ABOVE AVERAGE OCEAN SURFACE TEMPERATURES DOMINATE THE 
FAR EASTERN EQUATORIAL PACIFIC. SUB-SURFACE WATER TEMPERATURES WERE ABOVE 
AVERAGE OVER THE WESTERN AND CENTRAL EQUATORIAL PACIFIC, AT DEPTHS RANGING FROM 
75-250 METERS. THE FAIRLY LARGE AREA OF SUB-SURFACE WARMTH THAT HAD BEEN 
OBSERVED OVER THE EASTERN PACIFIC DURING THE PAST 6 WEEKS HAS MOSTLY ERODED 
AWAY. AVERAGE OCEAN HEAT CONTENT IN THE UPPER 300 METERS OF THE CENTRAL AND 
EAST-CENTRAL NEAR-EQUATORIAL PACIFIC REMAINED NEAR 0.7 C ABOVE AVERAGE. THE 
MADDEN-JULIAN OSCILLATION (MJO) HAS WEAKENED SIGNIFICANTLY FROM THAT SEEN IN 
MAY AND JUNE, AND AT THE CURRENT TIME IS NOT EXPECTED TO BE A SIGNIFICANT 
CONTRIBUTOR TO THE JULY OUTLOOK. THE REGION OF ENHANCED CONVECTION SHIFTED 
NORTHWARD FROM EASTERN INDONESIA TO THE PHILIPPINES AND THE SOUTHWEST NORTH 
PACIFIC, WHILE SUPPRESSED CONVECTION REMAINED SOUTH OF THE EQUATOR NEAR THE 
DATE LINE. ENHANCED LOW-LEVEL EASTERLY WIND ANOMALIES WERE OBSERVED OVER THE 
CENTRAL EQUATORIAL PACIFIC.

THE MOST RECENT LA NINA IS EXPECTED TO CONTINUE TO HAVE AN INDIRECT IMPACT ON 
THE U.S. CLIMATE IN JULY DUE PRIMARILY TO SOIL MOISTURE ANOMALIES. SPRINGTIME 
PRECIPITATION ANOMALIES ASSOCIATED WITH LA NINA HAVE PRODUCED LARGE AREAS OF 
ANOMALOUSLY DRY CONDITIONS FROM PARTS OF THE DESERT SOUTHWEST AND SOUTHERN 
ROCKIES EASTWARD ACROSS TEXAS AND THE GULF COAST TO THE CAROLINAS. ABNORMALLY 
WET SOIL MOISTURE CONDITIONS EXTEND FROM THE PACIFIC NORTHWEST TO THE UPPER 
GREAT LAKES AND FROM THE MID-MISSISSIPPI VALLEY NORTHEASTWARD TO NEW ENGLAND. 
SOIL MOISTURE ANOMALIES, IN TURN AFFECT THE CHANCES OF WARMER OR COOLER THAN 
NORMAL TEMPERATURES DUE TO ITS INFLUENCE ON THE AMOUNT OF SOLAR ENERGY BEING 
USED FOR EVAPORATION RATHER THAN FOR HEATING THE LOWER ATMOSPHERE. SOIL 
MOISTURE ANOMALIES CAN ALSO INFLUENCE PRECIPITATION THROUGH AN INCREASE OR 
DECREASE IN LOCAL MOISTURE SOURCES. THIS EFFECT IS MOST IMPORTANT IN DRIER 
REGIONS WHERE SOIL MOISTURE ANOMALIES RELATIVE TO CLIMATOLOGY ARE LARGER THAN 
IN NORMALLY WETTER REGIONS.

THE UPDATED TEMPERATURE OUTLOOK FOR JULY 2011 CALLS FOR ENHANCED CHANCES OF 
BELOW NORMAL TEMPERATURES ACROSS THE NORTHERN ROCKIES, THE NORTHERN GREAT 
PLAINS, AND THE ALASKA PANHANDLE. THIS IS INDICATED BY THE CFS MODEL, AND FOR 
THE LOWER 48 AREAS ALSO INCLUDES THE CONSTRUCTED ANALOG ON SOIL MOISTURE (CAS) 
TOOL, AND CURRENT SOIL MOISTURE ANOMALIES. UNUSUALLY DEEP SNOW PACK IN THE 
HIGHER ELEVATIONS OF THE NORTHERN ROCKIES ALSO FAVORS ENHANCED ODDS OF BELOW 
NORMAL TEMPERATURES. ABOVE NORMAL TEMPERATURES ARE FAVORED FROM PORTIONS OF THE 
SOUTHERN GREAT PLAINS AND LOUISIANA EASTWARD ALONG THE GULF COAST STATES TO THE 
FLORIDA PANHANDLE AND GEORGIA, AS WELL AS OVER ARIZONA AND SMALL PORTIONS OF 
ADJACENT STATES. INITIAL SOIL MOISTURE CONDITIONS ARE DRIER THAN USUAL ACROSS 
THESE AREAS. ELSEWHERE, WHICH INCLUDES MUCH OF THE CONTIGUOUS U.S. AND MOST OF 
ALASKA, EQUAL CHANCES (EC) OF BELOW-, NEAR-, AND ABOVE-NORMAL TEMPERATURES ARE 
PREDICTED. 

ENHANCED CHANCES FOR BELOW MEDIAN PRECIPITATION ARE INDICATED FROM EAST TEXAS 
EASTWARD ACROSS THE GULF COAST STATES TO GEORGIA, AS WELL AS FOR ARIZONA, 
SOUTHERN NEVADA, AND EXTREME SOUTHEASTERN CALIFORNIA. THIS IS LARGELY 
ATTRIBUTED TO THE EXPECTED PERSISTENCE OF VERY DRY SOIL MOISTURE CONDITIONS, 
THE CFS MODEL, THE LATEST RUNS OF THE OPERATIONAL GFS MODEL, AND THE CAS TOOL. 
THE PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION ARE ELEVATED ACROSS MUCH OF 
THE NORTHERN GREAT PLAINS AND THE ALASKA PANHANDLE, BASED ON THE CFS DYNAMICAL 
MODEL, THE CAS TOOL (TO A LESSER DEGREE), AND RECENT PRECIPITATION AND SOIL 
MOISTURE ANOMALIES. ENHANCED ODDS FOR ABOVE MEDIAN RAINFALL ARE ALSO INDICATED 
FOR THE FLORIDA PENINSULA, WHERE NWP MODELS PREDICT SURGES OF SUBTROPICAL 
MOISTURE DURING THE FIRST HALF OF THE MONTH. SIGNALS ARE CONFLICTING OR ABSENT 
ELSEWHERE, WHICH INCLUDES MOST OF BOTH THE LOWER 48 STATES AND ALASKA, 
RESULTING IN A FORECAST FOR EQUAL CHANCES (EC) OF BELOW-, NEAR-, AND 
ABOVE-MEDIAN PRECIPITATION. 

THERE IS STILL CONSIDERABLE UNCERTAINTY REGARDING THE SEASONAL PROGRESSION OF 
THE SOUTHWEST MONSOON. MONSOON MOISTURE IS CURRENTLY LOCATED OVER SOUTHERN AND 
CENTRAL MEXICO, WHICH IS WELL SOUTH OF WHERE IT TYPICALLY IS BY LATE JUNE. 
MOISTURE FROM TROPICAL STORM ARLENE MOVING WESTWARD INTO CENTRAL AND NORTHERN 
MEXICO IS HELPING TO PRE-CONDITION THESE VERY DRY AREAS TO SUPPORT THE 
NORTHWARD MIGRATION OF MONSOONAL MOISTURE EVENTUALLY INTO THE U.S. DESERT 
SOUTHWEST. IT STILL APPEARS THAT THE SUMMER MONSOON IS RUNNING SOMEWHAT BEHIND 
SCHEDULE, AND BY THE TIME THIS MOISTURE REACHES THE SOUTHWEST IN SIGNIFICANT 
QUANTITIES, THE LOCAL CLIMATOLOGIES WILL ALSO BE HIGHER. EQUAL CHANCES IS 
THOUGHT TO BE THE BEST BET FOR PRECIPITATION OVER NEW MEXICO AND WEST TEXAS 
WHERE THE UNCERTAINTY IS GREATER.


FORECASTER: ANTHONY ARTUSA


THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1981 AND 2010, FOLLOWING
THE WORLD METEOROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3 
COMPLETE DECADES AS THE CLIMATE REFERENCE PERIOD.  THE PROBABILITY ANOMALIES
FOR TEMPERATURE AND PRECIPITATION BASED ON THESE NEW NORMALS BETTER REPRESENT
SHORTER TERM CLIMATIC ANOMALIES THAN THE FORECASTS BASED ON OLDER NORMALS.



THE NEXT MONTHLY OUTLOOK...FOR AUG ... WILL BE ISSUED ON THU JUL 21 2011


THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD.

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