561  
FXUS06 KWBC 141902  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EDT TUE MAY 14 2024  
 
6-10 DAY OUTLOOK FOR MAY 20 - 24 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 DIFFERENCES STILL REMAIN WHEN CONSIDERING  
THE DAILY EVOLUTION OF VARIOUS FEATURES. TODAY’S MANUAL BLEND FEATURES  
WIDESPREAD POSITIVE HEIGHT ANOMALIES OVER THE NORTH PACIFIC, A WEAK SUBTROPICAL  
RIDGE CENTERED OVER SOUTHEASTERN TEXAS, AND TROUGHING OVER THE NORTHWESTERN AND  
NORTH-CENTRAL CONUS. WEAK TROUGHING IS ALSO FAVORED NEAR THE EAST COAST.  
 
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 MUCH OF THE CONUS WEST OF THE ROCKIES, ESPECIALLY THE  
NORTHWEST CONUS WHERE PROBABILITIES EXCEED 50%. PORTIONS OF SOUTHERN CALIFORNIA  
ALSO HAVE ENHANCED CHANCES OF BELOW-NORMAL TEMPERATURES, CONSISTENT WITH MOST  
FORECAST TOOLS. FOR ALASKA, INCREASED NORTHWESTERLY FLOW ALOFT FAVORS INCREASED  
CLOUDINESS AND BELOW-NORMAL TEMPERATURES FOR THE ALASKAN INTERIOR AND EXTENDING  
SOUTHEASTWARD THROUGH THE PANHANDLE, WHILE THE NORTH SLOPE TILTS SLIGHTLY  
TOWARDS ABOVE-NORMAL TEMPERATURES, AS INDICATED BY THE GEFS AND ECMWF  
REFORECAST TOOLS. THE HAWAII ERF CONSOLIDATION (CON) FAVORS ABOVE-NORMAL  
TEMPERATURES FOR THE ENTIRE STATE.  
 
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 MOST OF THE CONUS EAST OF THE ROCKIES. THE SUBTROPICAL RIDGE  
FAVORS BELOW-NORMAL PRECIPITATION FOR PORTIONS OF THE SOUTHERN CONUS,  
ESPECIALLY FOR PORTIONS OF SOUTHERN NEW MEXICO AND SOUTHEASTERN TEXAS. 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 AND BELOW-NORMAL  
PRECIPITATION IS SLIGHTLY FAVORED FOR THE SOUTHERN COAST AND THE PANHANDLE OF  
ALASKA. THE HAWAII CON INDICATES ABOVE-NORMAL PRECIPITATION FOR MOST OF THE  
STATE, WITH ODDS INCREASING FROM EAST TO WEST, WHILE NEAR-NORMAL PRECIPITATION  
IS MOST LIKELY FOR THE BIG ISLAND.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S 0Z 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: ABOVE AVERAGE, 4 OUT OF 5, WITH  
GOOD RUN-TO-RUN CONTINUITY AMONG FORECAST MODELS, OFFSET BY DIFFERENCES BETWEEN  
MODELS REGARDING STRENGTH AND POSITION OF VARIOUS SYNOPTIC FEATURES.  
 
8-14 DAY OUTLOOK FOR MAY 22 - 28 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 THE SOUTH-CENTRAL  
AND SOUTHEASTERN CONUS, 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 CHANCES FOR BELOW-NORMAL TEMPERATURES AS FAR AS THE GREAT LAKES, WHILE  
NEAR-NORMAL TEMPERATURES BECOME MOST LIKELY FOR THE NORTHEASTERN CONUS. WESTERN  
ALASKA 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, AND INDICATE A SIMILAR  
TILT FOR SOUTHEASTERN ALASKA AS WELL. MOST OF HAWAII CONTINUES TO BE FAVORED  
FOR ABOVE-NORMAL TEMPERATURES, ALTHOUGH NEAR-NORMAL TEMPERATURES ARE NOW MOST  
LIKELY FOR THE BIG ISLAND, CONSISTENT WITH TODAY’S AUTOBLEND AND HAWAII CON  
TOOL.  
 
SUBTROPICAL RIDGING OVER THE SOUTHERN CONUS CONTINUES TO FAVOR BELOW-NORMAL  
PRECIPITATION FOR PORTIONS OF THE FOUR CORNERS, SOUTHEASTERN TEXAS, AND SOUTH  
FLORIDA, 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 KAWAI.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 33% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN  
CENTERED ON DAY 11, AND 33% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON  
DAY 11  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, WITH  
GOOD RUN-TO-RUN CONTINUITY AMONG FORECAST MODELS, OFFSET BY DIFFERENCES BETWEEN  
MODELS REGARDING STRENGTH AND POSITION OF VARIOUS SYNOPTIC FEATURES.  
 
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:  
19710506 - 19730518 - 19520523 - 20060504 - 20060427  
 
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:  
19990527 - 19710505 - 19730519 - 19520521 - 20060504  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR MAY 20 - 24 2024  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B N OREGON B N NRN CALIF B N  
SRN CALIF B N IDAHO B A NEVADA B N  
W MONTANA B A E MONTANA B A WYOMING B A  
UTAH B A ARIZONA N N COLORADO A A  
NEW MEXICO A B N DAKOTA B A S DAKOTA B 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 A A MISSOURI A A  
ARKANSAS A A LOUISIANA A B WISCONSIN A A  
ILLINOIS A A MISSISSIPPI A N MICHIGAN A A  
INDIANA A A OHIO A A KENTUCKY A A  
TENNESSEE A A ALABAMA A N NEW YORK A A  
VERMONT A A NEW HAMP A N MAINE A A  
MASS A N CONN A N RHODE IS A N  
PENN A A NEW JERSEY A N W VIRGINIA A A  
MARYLAND A N DELAWARE A N VIRGINIA A N  
N CAROLINA A N S CAROLINA A N GEORGIA A N  
FL PNHDL A N FL PENIN A N AK N SLOPE A A  
AK ALEUTIAN N N AK WESTERN B A AK INT BSN N A  
AK S INT N N AK SO COAST N N AK PNHDL B N  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR MAY 22 - 28 2024  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B N OREGON B N NRN CALIF B N  
SRN CALIF B N IDAHO B N NEVADA B N  
W MONTANA B N E MONTANA B A WYOMING B A  
UTAH B N ARIZONA B B COLORADO B N  
NEW MEXICO A B N DAKOTA B A S DAKOTA B A  
NEBRASKA B A KANSAS N A OKLAHOMA A A  
N TEXAS A A 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 N A  
INDIANA N A OHIO N A KENTUCKY A A  
TENNESSEE A A ALABAMA A A NEW YORK N A  
VERMONT N N NEW HAMP N A MAINE N N  
MASS N A CONN N A RHODE IS N A  
PENN N A NEW JERSEY N A W VIRGINIA A A  
MARYLAND N A DELAWARE N A VIRGINIA A A  
N CAROLINA A A S CAROLINA A A GEORGIA A A  
FL PNHDL A N FL PENIN A N AK N SLOPE A A  
AK ALEUTIAN N N AK WESTERN B A AK INT BSN N A  
AK S INT N N AK SO COAST N N AK PNHDL A 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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