672  
FXUS06 KWBC 131922  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EDT MON MAY 13 2024  
 
6-10 DAY OUTLOOK FOR MAY 19 - 23 2024  
 
TODAY’S MODEL SOLUTIONS HAVE COME INTO BETTER AGREEMENT OVER THE LAST FEW DAYS  
AND THE GEFS, ECMWF, AND CMCE ALL DEPICT A SIMILAR SYNOPTIC PICTURE OVER THE  
6-10 DAY FORECAST PERIOD, ALTHOUGH SIGNIFICANT DIFFERENCES STILL REMAIN WHEN  
CONSIDERING THE DAILY EVOLUTION OF VARIOUS FEATURES. THE ABOVE ENSEMBLES WERE  
WEIGHTED EQUALLY AND THE RESULTANT MANUAL BLEND FEATURES WIDESPREAD POSITIVE  
HEIGHT ANOMALIES OVER THE NORTH PACIFIC, A WEAK SUBTROPICAL RIDGE CENTERED OVER  
NORTHERN MEXICO, AND WEAK TROUGHING OVER BOTH THE WEST AND EAST COASTS.  
 
SUBTROPICAL RIDGING FAVORS ABOVE-NORMAL TEMPERATURES FOR MUCH OF THE SOUTHERN  
AND EASTERN CONTIGUOUS U.S. (CONUS), WITH PROBABILITIES EXCEEDING 80% FOR  
PORTIONS OF SOUTH TEXAS. TROUGHING OVER THE WEST COAST FAVORS BELOW-NORMAL  
TEMPERATURES FOR PORTIONS OF THE NORTHWEST CONUS, ESPECIALLY WASHINGTON WHERE  
PROBABILITIES EXCEED 50%. PORTIONS OF SOUTHERN CALIFORNIA ALSO TILT SLIGHTLY  
TOWARD BELOW-NORMAL TEMPERATURES, CONSISTENT WITH MOST FORECAST TOOLS. FOR  
ALASKA, INCREASED NORTHWESTERLY FLOW ALOFT FAVORS INCREASED CLOUDINESS AND  
BELOW-NORMAL TEMPERATURES FOR MUCH OF THE STATE, EXCEPT FOR THE NORTH SLOPE  
WHICH TILTS SLIGHTLY TOWARDS ABOVE-NORMAL TEMPERATURES, AS INDICATED BY THE  
GEFS AND ECMWF REFORECAST TOOLS. THE HAWAII ERF CONSOLIDATION FAVORS  
ABOVE-NORMAL TEMPERATURES FOR THE ENTIRE STATE.  
 
WEAK TROUGHING OVER BOTH COASTS AND POSITIVE HEIGHT ANOMALIES CENTERED OVER  
NORTHERN MEXICO DEVELOP A STRONGER THAN NORMAL JET STREAM FOR THIS TIME OF  
YEAR, FAVORING A MORE ACTIVE PATTERN WHICH TILTS THE ODDS TOWARD ABOVE-NORMAL  
PRECIPITATION FOR MUCH OF THE CONUS. THE SUBTROPICAL RIDGE FAVORS BELOW-NORMAL  
PRECIPITATION FOR PORTIONS OF THE SOUTHERN CONUS, ESPECIALLY FOR PORTIONS OF  
SOUTHERN NEW MEXICO. MUCH OF ALASKA TILTS TOWARDS ABOVE-NORMAL PRECIPITATION  
WITH WEAK TROUGHING FAVORED OVER EASTERN SIBERIA ALTHOUGH MODEL SOLUTIONS  
GENERALLY KEEP THE ENHANCED POTENTIAL FOR PRECIPITATION CONFINED TO THE  
MAINLAND SO NEAR-NORMAL PRECIPITATION IS FAVORED FOR THE PANHANDLE OF ALASKA.  
THE HAWAII CON INDICATES ABOVE-NORMAL PRECIPITATION FOR THE WHOLE STATE, WITH  
ODDS INCREASING FROM EAST TO WEST.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 33% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN  
CENTERED ON DAY 8, AND 33% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY  
8  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, WITH  
MODERATE AGREEMENT AMONG FORECAST MODELS AND TOOLS REGARDING THE OVERALL  
SYNOPTIC PICTURE, OFFSET BY DIFFERENCES BETWEEN MODELS REGARDING STRENGTH AND  
POSITION OF VARIOUS FEATURES.  
 
8-14 DAY OUTLOOK FOR MAY 21 - 27 2024  
 
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY (WEEK-2) PERIOD PREDICT A  
DE-AMPLIFICATION OF THE 500-HPA CIRCULATION PATTERN RELATIVE TO THE 6-10 DAY  
PERIOD ACROSS NORTH AMERICA AND THE SURROUNDING REGIONS. HEIGHT ANOMALIES ARE  
WEAKER RELATIVE TO THE 6-10 DAY PERIOD AS THE SYNOPTIC PATTERN BECOMES MORE  
ZONAL AND SPREAD AMONG MODEL SOLUTIONS INCREASES. DURING WEEK-2, POSITIVE  
500-HPA HEIGHT ANOMALIES PERSIST OVER THE NORTH PACIFIC AND NORTHERN MEXICO,  
WHILE WEAK TROUGHING CONTINUES OVER THE COASTS. THIS PERSISTENCE OF THE  
SYNOPTIC PATTERN RESULTS IN SIMILAR OUTLOOKS BETWEEN FORECAST PERIODS FOR BOTH  
TEMPERATURE AND PRECIPITATION.  
 
ABOVE-NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR THE SOUTHERN CONUS EAST OF  
THE ROCKIES. CONTINUED TROUGHING OVER BOTH COASTS FAVORS AN EASTWARD EXPANSION  
OF CHANCE FOR BELOW-NORMAL TEMPERATURES AS FAR AS THE GREAT LAKES, WHILE  
NEAR-NORMAL TEMPERATURES BECOME MOST LIKELY FOR THE NORTHEASTERN CONUS. FOR  
ALASKA MUCH OF THE STATE CONTINUES TO TILT TOWARDS BELOW-NORMAL TEMPERATURES  
WITH NORTHWESTERLY FLOW ALOFT CONTINUING, WHILE REFORECAST TOOLS CONTINUE TO  
FAVOR A SLIGHT TILT TOWARDS ABOVE-NORMAL TEMPERATURES FOR THE NORTH SLOPE.  
 
SUBTROPICAL RIDGING OVER NORTHERN MEXICO CONTINUES TO FAVOR BELOW-NORMAL  
PRECIPITATION FOR PORTIONS OF NEW MEXICO AND WEST TEXAS, WHILE THE WEAK  
TROUGHING PRESENT ON BOTH COASTS RESULTS IN A TILT TOWARDS ABOVE-NORMAL  
PRECIPITATION FOR MUCH OF THE CONUS, SUPPORTED BY THE MAJORITY OF FORECAST  
TOOLS. CONTINUED TROUGHING OVER SIBERIA FAVORS ABOVE-NORMAL PRECIPITATION FOR  
MUCH OF THE ALASKAN MAINLAND, HOWEVER SURFACE FLOW IS FAVORED TO BECOME  
SOUTHEASTERLY OVER THE PANHANDLE, RESULTING IN A SLIGHT TILT TOWARDS  
BELOW-NORMAL PRECIPITATION. ABOVE-NORMAL PRECIPITATION CONTINUES TO BE FAVORED  
FOR HAWAII, ESPECIALLY THE WESTERN ISLANDS.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 35% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 35% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN  
CENTERED ON DAY 11, AND 30% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON  
DAY 11  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, WITH  
MODERATE AGREEMENT AMONG FORECAST MODELS AND TOOLS REGARDING THE OVERALL  
SYNOPTIC PICTURE, OFFSET BY DIFFERENCES BETWEEN MODELS REGARDING STRENGTH AND  
POSITION OF VARIOUS FEATURES AND WEAKER HEIGHT ANOMALIES.  
 
FORECASTER: DANIEL BARANDIARAN  
 
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:  
19730518 - 19710505 - 20060504 - 19520520 - 19610519  
 
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:  
19730519 - 19520520 - 19710525 - 19710505 - 19610519  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR MAY 19 - 23 2024  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B N OREGON B N NRN CALIF N A  
SRN CALIF B A IDAHO B A NEVADA N A  
W MONTANA B A E MONTANA B A WYOMING B A  
UTAH N A ARIZONA N B COLORADO A A  
NEW MEXICO A B N DAKOTA B A S DAKOTA N A  
NEBRASKA N A KANSAS A A OKLAHOMA A N  
N TEXAS A N S TEXAS A B W TEXAS A B  
MINNESOTA N A IOWA N A MISSOURI A A  
ARKANSAS A A LOUISIANA A N 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 A 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 A FL PENIN A A AK N SLOPE N A  
AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A  
AK S INT B A AK SO COAST B N AK PNHDL B N  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR MAY 21 - 27 2024  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B A OREGON B N NRN CALIF B N  
SRN CALIF B N IDAHO B A NEVADA B A  
W MONTANA B A E MONTANA B A WYOMING B A  
UTAH B A ARIZONA B N COLORADO B A  
NEW MEXICO A B N DAKOTA B A S DAKOTA B A  
NEBRASKA B A KANSAS N A OKLAHOMA A A  
N TEXAS A N S TEXAS A N W TEXAS A N  
MINNESOTA B A IOWA B A MISSOURI N A  
ARKANSAS A A LOUISIANA A N WISCONSIN B A  
ILLINOIS N A MISSISSIPPI A A MICHIGAN B A  
INDIANA N A 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 N A  
N CAROLINA A A S CAROLINA A A GEORGIA A A  
FL PNHDL A A FL PENIN A N AK N SLOPE A A  
AK ALEUTIAN B A AK WESTERN B A AK INT BSN N A  
AK S INT B A AK SO COAST B N AK PNHDL B N  
 
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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