037  
FXUS06 KWBC 021903  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EDT THU MAY 02 2024  
 
6-10 DAY OUTLOOK FOR MAY 08 - 12 2024  
 
THE ECENS AND GEFS PREDICTED 500-HPA HEIGHTS CONTINUE TO BE IN FAIRLY GOOD  
AGREEMENT WITH THE CANADIAN ENSEMBLE MEAN COMING INTO BETTER AGREEMENT TODAY.  
NEGATIVE 500-HPA HEIGHT ANOMALIES ARE FORECAST ACROSS ALASKA, THE WESTERN AND  
NORTHERN CONTIGUOUS U.S. (CONUS), AND NEW ENGLAND. NEAR- TO ABOVE-NORMAL  
500-HPA HEIGHTS ARE FORECAST ACROSS THE SOUTHEASTERN CONUS. THE NEGATIVE  
MID-LEVEL HEIGHT ANOMALIES ACROSS THE WEST ARE FORECAST TO PROGRESS EASTWARD  
ACROSS THE NORTHERN TIER DURING THE PERIOD. POSITIVE ANOMALIES ACROSS THE  
EASTERN PACIFIC MAY INTRUDE INTO PARTS OF THE NORTHWEST BY THE END OF THE 6-10  
DAY PERIOD, REDUCING THE MEAN HEIGHTS ACROSS THE NORTHWEST RELATIVE TO  
YESTERDAY.  
 
MID-LEVEL RIDGING ACROSS THE SOUTHEASTERN CONUS IS FORECAST TO BRING  
ABOVE-NORMAL TEMPERATURES TO MUCH OF THE EASTERN CONUS DURING THE 6-10 DAY  
PERIOD. THE HIGHEST CONFIDENCE FOR ABOVE-NORMAL TEMPERATURES REMAINS ACROSS THE  
SOUTHEAST INTO THE MID-ATLANTIC AHEAD OF ANY POTENTIAL FRONTAL SYSTEMS  
ASSOCIATED WITH THE NEGATIVE 500-HPA HEIGHT ANOMALIES FORECAST TO PROGRESS  
ACROSS THE CONUS LATER IN THE PERIOD. THERE IS REDUCED CONFIDENCE IN  
ABOVE-NORMAL TEMPERATURES IN PARTS OF THE WESTERN GREAT LAKES WHERE THE  
MID-LEVEL TROUGH IS FORECAST TO INFLUENCE BY THE END OF THE PERIOD. IN THE  
WEST, BELOW-NORMAL TEMPERATURES ARE GENERALLY FAVORED WITH THE HIGHEST  
PROBABILITIES ACROSS PARTS OF THE NORTHERN GREAT BASIN. IN ALASKA, BELOW-NORMAL  
TEMPERATURES ARE LIKELY ACROSS THE ALASKA PENINSULA AND SOUTHWESTERN MAINLAND.  
IN SOUTHEAST ALASKA, BELOW-NORMAL TEMPERATURES ARE SLIGHTLY FAVORED. THE  
INTERIOR MAINLAND IS FORECAST TO SEE NEAR-NORMAL TEMPERATURES. IN HAWAII,  
BELOW-NORMAL TEMPERATURES ARE FAVORED BENEATH MID-LEVEL TROUGHING.  
 
AS THE MID-LEVEL TROUGH, INITIALLY ALONG THE WEST COAST, PROGRESSES EASTWARD  
ABOVE NORMAL PRECIPITATION IS FORECAST BENEATH AND JUST AHEAD OF THE TROUGH.  
THE FOCUS OF ABOVE-NORMAL PRECIPITATION CHANCES HAS SHIFTED SOUTH RELATIVE TO  
YESTERDAY WITH A BROAD TROUGH NOW HANGING ACROSS THE COUNTRY. THEREFORE,  
ABOVE-NORMAL PRECIPITATION IS NOW FORECAST FOR THE SOUTHEAST, TENNESSEE AND  
LOWER-MISSISSIPPI VALLEYS. WHILE THE GEFS PRECIPITATION REFORECAST TOOL REMAINS  
WEAKER RELATIVE TO THE ECENS REFORECAST THE SPATIAL PATTERN OF THE ANOMALIES IS  
CONSISTENT, INCREASING CONFIDENCE IN ABOVE-NORMAL ACROSS THESE REGIONS.  
HOWEVER, BELOW-NORMAL PRECIPITATION REMAINS FAVORED FOR FLORIDA AND THE PARTS  
OF THE RIO GRANDE VALLEY AHEAD OF THE MEAN TROUGH. ALONG THE WEST COAST,  
BELOW-NORMAL PRECIPITATION CHANCES ARE FORECAST AS POSITIVE 500-HPA HEIGHT  
ANOMALIES BUILD INTO THE PACIFIC NORTHWEST. IN ALASKA, ANOMALOUSLY BELOW-NORMAL  
500-HPA HEIGHTS SUPPORTS ABOVE-NORMAL PRECIPITATION ACROSS MUCH OF THE STATE. A  
SLIGHT TILT TOWARDS ABOVE-NORMAL PRECIPITATION IS FAVORED ACROSS MUCH OF HAWAII  
WITH NEGATIVE 500-HPA HEIGHT ANOMALIES FORECAST.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 30% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 20%  
OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD  
AGREEMENT AMONG THE DYNAMICAL MODEL TOOLS BUT PATTERN IS BECOMING MORE  
TRANSIENT REDUCING CONFIDENCE.  
 
8-14 DAY OUTLOOK FOR MAY 10 - 16 2024  
 
THE DYNAMICAL MODELS HAVE WEAK MEAN MID-LEVEL HEIGHT ANOMALIES FOR THE WEEK-2  
PERIOD LEADING TO INCREASED UNCERTAINTY ACROSS MUCH OF THE COUNTRY. THE  
STRONGEST ANOMALIES ARE POSITIVE ACROSS THE PACIFIC NORTHWEST AND EAST PACIFIC.  
ELSEWHERE, NEAR TO BELOW-NORMAL MID-LEVEL HEIGHTS ARE FAVORED ACROSS MUCH OF  
THE CONUS, ALASKA, AND THE CENTRAL PACIFIC. THE STRONGEST MEAN 500-HPA HEIGHT  
NEGATIVE ANOMALIES ARE FOUND OVER THE GREAT LAKES AND NORTHEAST. POSITIVE  
HEIGHT ANOMALIES ARE SLIGHTLY STRONGER ACROSS PARTS OF THE GULF OF MEXICO AND  
SOUTHERN PLAINS RELATIVE TO YESTERDAY.  
 
ABOVE-NORMAL TEMPERATURES REMAIN FAVORED ACROSS THE SOUTHEASTERN CONUS DURING  
THE 8-14 DAY PERIOD. THE STRONGEST PROBABILITIES ARE FORECAST CLOSEST TO THE  
GULF COAST AND THE FLORIDA PENINSULA, NEAR THE ABNORMALLY STRONG SUBTROPICAL  
RIDGE. A WEAKENING TROUGH IS FORECAST ACROSS THE INTERIOR MOUNTAIN WEST FOR  
MUCH OF THE PERIOD. THIS MAY BRING UNSETTLED WEATHER TO THE REGION AND  
GENERALLY COOLER TEMPERATURES. AS THIS TROUGH PROGRESSES EAST IT WILL DISPLACE  
WARMER THAN NORMAL CONDITIONS AHEAD OF IT. THEREFORE, NEAR-NORMAL TEMPERATURES  
ARE FORECAST FOR THE GREAT LAKES AND NORTHEAST. ALONG THE WEST COAST, A SLIGHT  
TILT TOWARDS ABOVE-NORMAL TEMPERATURES IS FAVORED AS RIDGING IS FORECAST TO  
BEGIN BUILDING INTO THE REGION DURING WEEK-2. IN ALASKA, BELOW-NORMAL  
TEMPERATURES ARE FAVORED ACROSS MUCH OF THE STATE WITH THE STRONGEST CHANCES  
FORECAST ACROSS THE SOUTHERN PORTIONS. IN HAWAII, NEAR-NORMAL TEMPERATURES ARE  
FORECAST WITH NEAR-NORMAL HEIGHTS FAVORED OVER THE STATE.  
 
BELOW-NORMAL PRECIPITATION IS FAVORED FOR THE PACIFIC NORTHWEST AND PARTS OF  
NORTHERN CALIFORNIA WITH RIDGING BUILDING INTO THE REGION. GENERALLY, UNSETTLED  
WEATHER IS FORECAST ACROSS THE ROCKIES AND INTO THE PLAINS THROUGH TO THE  
EASTERN SEABOARD WITH A BROAD MID-LEVEL TROUGH FORECAST ACROSS THE CONUS DURING  
WEEK-2. THE STRONGEST CHANCES FOR ABOVE-NORMAL PRECIPITATION ARE FORECAST FOR  
PORTIONS OF THE SOUTHERN MID-ATLANTIC, SOUTHEAST, AND TENNESSEE VALLEY AS A  
SOMEWHAT STATIONARY FRONT MAY BECOME ESTABLISHED AND MAY HELP TO FOCUS  
ADDITIONAL PRECIPITATION INTO THESE REGIONS. A SECOND AREA OF SLIGHTLY ENHANCED  
CHANCES FOR ABOVE-NORMAL PRECIPITATION IS OVER CLIMATOLOGICALLY QUITE DRY  
REGIONS OF THE INTERIOR WEST WHERE A SMALL AMOUNT OF PRECIPITATION MAY BRING  
WEEK-2 TOTALS ABOVE-NORMAL. IN FLORIDA, NEAR-NORMAL PRECIPITATION IS FAVORED  
DURING THE CLIMATOLOGICALLY DRIEST TIME OF THE YEAR. IN ALASKA, ABOVE-NORMAL  
PRECIPITATION IS GENERALLY FAVORED ACROSS THE STATE WITH UNSETTLED WEATHER  
BENEATH A MID-LEVEL TROUGH CONTINUING. MEANWHILE, ABOVE-NORMAL PRECIPITATION IS  
AGAIN SLIGHTLY FAVORED FOR HAWAII CONSISTENT WITH THE CONSOLIDATION OF TOOLS.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 5% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 35% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 20%  
OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: AVERAGE, 3 OUT OF 5, GOOD  
AGREEMENT IN THE MODEL TOOLS OFFSET BY THE PROGRESSIVE PATTERN LEADING TO  
DIFFERENCES IN TIMING AMONG THE TOOLS AND LOW MID-LEVEL HEIGHT ANOMALIES.  
 
FORECASTER: RYAN BOLT  
 
NOTES:  
 
AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OCCASIONALLY MANUAL  
INTERVENTION IS NECESSARY TO ADDRESS QUALITY CONTROL AND CONSISTENCY ISSUES. IN  
THESE CASES, FORECASTS ARE MANUALLY DRAWN BUT A FULL DISCUSSION IS NOT ISSUED.  
 
THE NOTATION FOR THE CATEGORICAL FORECAST INDICATED ON THE MAPS IS THE SAME AS  
THAT IN THE TABLES: A-ABOVE N-NEAR NORMAL B-BELOW  
 
THE TEMPERATURE MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WARMER (ORANGE,  
"A"), COLDER (BLUE, "B"), OR CLOSE TO (UNSHADED, "N"). HISTORICAL AVERAGE  
VALUES FOR THE CALENDAR PERIOD OF THE FORECAST (DASHES, "F"). LABELS ON THE  
SHADED LINES GIVE THE PROBABILITY (> 33%) OF THE MORE LIKELY CATEGORY (B OR A).  
PROBABILITY OF N IS ALWAYS < 40%.  
 
THE PRECIPITATION MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WETTER (GREEN,  
"A"), DRIER (TAN, "B"), OR CLOSE TO (UNSHADED, "N"). HISTORICAL MEDIAN VALUES  
FOR THE CALENDAR PERIOD OF THE FORECAST (DASHES, "INCHES"). LABELS ON THE  
SHADED LINES GIVE THE PROBABILITY (> 33%) OF THE MORE LIKELY CATEGORY (B OR A).  
PROBABILITY OF N IS ALWAYS < 40%.  
 
IN THE SOUTHWEST AND OTHER CLIMATOLOGICALLY DRY REGIONS - THERE WILL BE A  
GREATER THAN 33.3% CHANCE OF NO PRECIPITATION AND OCCASIONALLY EVEN A NORMAL  
(I.E. MEDIAN) VALUE OF ZERO - ESPECIALLY DURING THE DRY SEASONS. IN SUCH CASES  
A FORECAST OF NEAR NORMAL IS EFFECTIVELY A FORECAST OF LITTLE OR NO  
PRECIPITATION.  
 
THE CLIMATE PREDICTION CENTER USES 1991-2020 BASE PERIOD MEANS AS REFERENCE IN  
THE CLIMATE OUTLOOKS.  
 
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON MAY  
16.  
 
ANALOGS TO THE 5 DAY MEAN OBSERVED PATTERN CENTERED 3 DAYS AGO (D-3)  
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE  
INCLUDE THE 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES:  
19850423 - 19790412 - 19640503 - 20030516 - 19730419  
 
ANALOGS TO THE 7 DAY MEAN OBSERVED PATTERN CENTERED 4 DAYS AGO (D-4)  
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE  
INCLUDE THE 7 DAY PERIODS CENTERED ON THE FOLLOWING DATES:  
19640504 - 19850422 - 19790411 - 19990515 - 20030506  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR MAY 08 - 12 2024  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B B OREGON B B NRN CALIF B B  
SRN CALIF B N IDAHO B N NEVADA B N  
W MONTANA B A E MONTANA B A WYOMING B A  
UTAH B A ARIZONA B N COLORADO B A  
NEW MEXICO B N N DAKOTA B A S DAKOTA B A  
NEBRASKA B A KANSAS N N OKLAHOMA A A  
N TEXAS A N S TEXAS A B W TEXAS A N  
MINNESOTA N A IOWA N A MISSOURI A A  
ARKANSAS A A LOUISIANA A A WISCONSIN N A  
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A  
INDIANA A A OHIO A A KENTUCKY A A  
TENNESSEE A A ALABAMA A A NEW YORK A A  
VERMONT A A NEW HAMP A A MAINE N A  
MASS A A CONN A A RHODE IS A A  
PENN A A NEW JERSEY A A W VIRGINIA A A  
MARYLAND A A DELAWARE A A VIRGINIA A A  
N CAROLINA A A S CAROLINA A A GEORGIA A A  
FL PNHDL A N FL PENIN A B AK N SLOPE N A  
AK ALEUTIAN B A AK WESTERN B A AK INT BSN N A  
AK S INT B A AK SO COAST B A AK PNHDL B A  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR MAY 10 - 16 2024  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A B OREGON A B NRN CALIF A N  
SRN CALIF B A IDAHO N N NEVADA N A  
W MONTANA N N E MONTANA N N WYOMING B A  
UTAH B A ARIZONA B N COLORADO B A  
NEW MEXICO B A N DAKOTA N N S DAKOTA B N  
NEBRASKA B A KANSAS B A OKLAHOMA N A  
N TEXAS A A S TEXAS A A W TEXAS N A  
MINNESOTA N N IOWA B N MISSOURI N A  
ARKANSAS A A LOUISIANA A A WISCONSIN N N  
ILLINOIS N N MISSISSIPPI A A MICHIGAN N N  
INDIANA N N OHIO N A KENTUCKY N A  
TENNESSEE A A ALABAMA A A NEW YORK N A  
VERMONT N A NEW HAMP N A MAINE N A  
MASS N A CONN N A RHODE IS N A  
PENN N A NEW JERSEY N A W VIRGINIA N A  
MARYLAND N A DELAWARE N A VIRGINIA A A  
N CAROLINA A A S CAROLINA A A GEORGIA A A  
FL PNHDL A A FL PENIN A N AK N SLOPE N A  
AK ALEUTIAN B A AK WESTERN B A AK INT BSN N A  
AK S INT B A AK SO COAST B A AK PNHDL B A  
 
LEGEND  
TEMPS WITH RESPECT TO NORMAL PCPN WITH RESPECT TO MEDIAN  
A - ABOVE N - NEAR NORMAL A - ABOVE N - NEAR MEDIAN  
B - BELOW B - BELOW  
 
THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL  
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE  
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.  
 
FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS  
PMDMRD.  
 

 
 
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