006
FXUS06 KWBC 241902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI MAY 24 2024
6-10 DAY OUTLOOK FOR MAY 30 - JUN 03, 2024
A MODERATELY AMPLIFIED MID-LEVEL HEIGHT PATTERN IS FORECAST ACROSS THE CONUS AT
THE OUTSET OF THE PERIOD. TROUGHING IS PREDICTED ACROSS THE NORTHEASTERN CONUS,
WITH A NEGATIVE 500-HPA ANOMALY CENTER JUST OFF THE NORTHEAST COAST, AND
SLIGHTLY SUBNORMAL 500-HPA HEIGHTS ARE ALSO EXPECTED IN PARTS OF WESTERN CANADA
AND THE NORTHWESTERN CONUS. MEANWHILE, MID-LEVEL RIDGING IS ANTICIPATED OVER
THE CENTRAL AND SOUTHERN CONUS, WITH THE GREATEST POSITIVE HEIGHT ANOMALIES
COVERING THE PLAINS AND MISSISSIPPI VALLEY. THESE FEATURES ARE FORECAST TO
SLOWLY DEAMPLIFY DURING THE PERIOD, RESULTING IN A SOMEWHAT MORE ZONAL
MID-LEVEL FLOW PATTERN ACROSS THE CONUS BY DAY-10. FOLLOWING A GENERALLY WEAK
MID-LEVEL FLOW PATTERN AT THE BEGINNING OF THE PERIOD ACROSS ALASKA, TROUGHING
AND A CLOSED MID-LEVEL LOW ARE FORECAST TO DEVELOP ACROSS THE BERING SEA AND
SOUTHWESTERN ALASKA, ENCROACHING ON SOUTHERN MAINLAND ALASKA LATE IN THE
PERIOD. NEAR-NORMAL HEIGHTS ARE FORECAST ACROSS THE HAWAIIAN ISLANDS, WITH WEAK
MEAN TROUGHING NORTHWEST OF THE ISLAND CHAIN. THE MAIN DIFFERENCES BETWEEN THE
ENSEMBLE MEANS REGARD THE EVOLUTION OF THE MID-LEVEL TROUGH NEAR ALASKA, AND
THE MEAN 500-HPA HEIGHTS IN THE PACIFIC NORTHWEST. THE CANADIAN ENSEMBLE MEAN
MORE CLOSELY RESEMBLES TELECONNECTIONS BASED ON THE STRONG MID-LEVEL RIDGES IN
THE CENTRAL NORTH PACIFIC AND THE NORTHERN NORTH ATLANTIC OCEANS, SO ITS
SOLUTION IS FAVORED, WHICH MAINTAINS NEAR TO SLIGHTLY ABOVE-NORMAL 500-HPA
HEIGHTS IN THE MEAN OVER THE PACIFIC NORTHWEST, WITH LESS INFLUENCE FROM ANY
EASTWARD EXTENSION OF THE LOW HEIGHTS AFFECTING ALASKA AND NEARBY AREAS. AS A
RESULT, TEMPERATURE AND PRECIPITATION MAPS REPRESENT A BLEND OF THE VARIOUS
TOOLS, SHADED TOWARD THE RAW, BIAS-CORRECTED, AND REFORECAST TOOLS DERIVED FROM
THE CANADIAN ENSEMBLE.
TROUGHING FAVORS INCREASED PROBABILITIES OF BELOW-NORMAL TEMPERATURES ACROSS
PORTIONS OF THE OHIO AND TENNESSEE VALLEY, MID-ATLANTIC, AND NORTHEAST.
ENHANCED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE FAVORED ACROSS
NORTHERN NEW ENGLAND AND CLOSER TO THE GULF COAST AND SOUTHEAST, UNDERNEATH
NEAR- TO ABOVE-NORMAL 500-HPA HEIGHTS. INCREASED CHANCES FOR ABOVE-NORMAL
TEMPERATURES ARE FAVORED OVER MUCH OF THE CENTRAL AND WESTERN CONUS DUE TO THE
ANTICIPATED MID-LEVEL RIDGING AND INCREASED SOUTHWESTERLY SURFACE FLOW, WITH
BELOW-NORMAL TEMPERATURES WEAKLY FAVORED ACROSS PARTS OF THE PACIFIC NORTHWEST
DUE TO THE INFLUENCE FROM WEAK TROUGHING EARLY IN THE PERIOD AND MEAN NORTHERLY
SURFACE WINDS FROM HIGHER PRESSURES OVER THE NORTH PACIFIC. ABOVE-NORMAL
TEMPERATURE CHANCES ARE INCREASED OVER PARTS OF NORTHERN AND CENTRAL MAINLAND
ALASKA, WHILE BELOW-NORMAL TEMPERATURE PROBABILITIES ARE INCREASED OVER
SOUTHERN ALASKA, INCLUDING PARTS OF THE ALEUTIANS AND SOUTHEAST ALASKA, CLOSER
TO THE MID-LEVEL TROUGH AND SURFACE STORMINESS. SURFACE HIGH PRESSURE TO THE
NORTHEAST AND SLIGHTLY LOWER 500-HPA HEIGHTS IN CENTRAL HAWAII WEAKLY FAVORS
SUBNORMAL TEMPERATURES THERE, WITH NO TILT OF THE ODDS IDENTIFIED IN
NORTHWESTERN AND SOUTHEASTERN PARTS OF THE STATE.
ENHANCED NORTHWESTERLY MID-LEVEL FLOW AND SURFACE HIGH PRESSURE ON THE BACKSIDE
OF THE WEAKENING TOUGH IN THE EAST FAVOR ENHANCED CHANCES FOR BELOW-NORMAL
PRECIPITATION ACROSS MOST OF THE EASTERN CONUS, EXTENDING TO THE CENTRAL GULF
COAST. MEANWHILE, SOUTHERLY RETURN FLOW WEST OF THE SURFACE HIGH INCREASES THE
ODDS OF ABOVE-NORMAL PRECIPITATION ACROSS PORTIONS OF THE GREAT PLAINS AND
MISSISSIPPI VALLEY, SUPPORTED BY MOST OF THE RAW AND REFORECAST TOOLS FROM THE
ECMWF ENSEMBLE, CANADIAN ENSEMBLE, AND GEFS. FARTHER WEST, BELOW-NORMAL
PRECIPITATION PROBABILITIES ARE SLIGHTLY ELEVATED OVER MUCH OF THE WESTERN
CONUS UNDERNEATH A RELATIVELY WEAK MID-LEVEL FLOW PATTERN NEAR THE
LOW-AMPLITUDE 500-HPA RIDGE AXIS, EXCEPT FOR PORTIONS OF THE PACIFIC NORTHWEST
WHERE NEAR- TO ABOVE-NORMAL PRECIPITATION CHANCES ARE INCREASED DUE TO GREATER
INFLUENCE FROM WEAK TROUGHING OVER WESTERN CANADA. ABOVE-NORMAL PRECIPITATION
CHANCES ARE ELEVATED OVER MOST OF ALASKA DUE TO THE TREND TOWARD INCREASED
TROUGHING TO THE SOUTH AND SOUTHWEST OF THE STATE LATER IN THE PERIOD,
SUPPORTED BY MOST OF THE DYNAMICAL PRECIPITATION FORECAST TOOLS. IN HAWAII,
WEAK SURFACE FLOW SOUTH OF A HIGH PRESSURE CENTER AND A NONDESCRIPT 500-HPA
PATTERN FAVORS NEAR-NORMAL PRECIPITATION.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S GFS
SUPERENSEMBLE MEAN CENTERED ON DAY 8, 20% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 60% 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, DUE TO
GOOD AGREEMENT AMONG THE FORECAST TOOLS, OFFSET BY DECREASING AMPLIFICATION
TOWARD THE END OF THE PERIOD.
8-14 DAY OUTLOOK FOR JUN 01 - 07 2024
A TRANSITIONAL MID-LEVEL HEIGHT PATTERN IS PREDICTED ACROSS THE CONUS DURING
WEEK-2. ALTHOUGH THE PERIOD IS EXPECTED TO BEGIN WITH SOME HINTS OF LINGERING
TROUGHING (RIDGING) ACROSS THE EASTERN (WEST-CENTRAL) CONUS, THE OVERALL
PATTERN IS FORECAST TO BECOME MORE ZONAL. BY THE END OF THE PERIOD, THE 0Z
GEFS, ECMWF, AND CANADIAN ENSEMBLES ALL DEPICT AT LEAST SLIGHTLY ABOVE-NORMAL
500-HPA HEIGHTS EXPANDING OVER MOST OF THE CONUS. THE GEFS AND ECMWF ENSEMBLE
MEANS SHOW THE PATTERN SHIFTING TOWARD SOME LOW-AMPLITUDE RELATIVE RIDGING AND
ANTICYCLONICD MID-LEVEL FLOW OVER THE INTERIOR WESTERN CONUS, WITH CYCLONIC
MID-LEVEL FLOW COVERING THE EASTERN CONUS DESPITE SLIGHTLY ABOVE-NORMAL 500-HPA
HEIGHTS. THE CANADIAN ENSEMBLE MEAN IS THE BROADEST WITH THE EVENTUAL COVERAGE
OF ABOVE-NORMAL 500-HPA HEIGHTS AND SHOWS MORE ZONAL MID-LEVEL FLOW THAN THE
OTHER ENSEMBLE MEANS, AND BASED ON CONSISTENCY FROM ITS FAVORED SOLUTION DURING
THE 6- TO 10-DAY PERIOD, IT IS AGAIN THE PREFERRED SOLUTION FOR WEEK-2, THOUGH
WITH LOWER CONFIDENCE DUE TO THE TRANSITIONAL PATTERN. A POTENT TROUGH IS
FORECAST TO MOVE SLOWLY ACROSS THE ALEUTIANS AND SOUTHERN ALASKA DURING WEEK-2,
WHICH LOOKS TO WEAKEN AS IT TRACKS EASTWARD BEFORE RELOADING FARTHER TO THE
WEST, RESULTING IN CONTINUED SIGNIFICANT MID-LEVEL TROUGHING NEAR THE
SOUTH-CENTRAL OR SOUTHWESTERN PARTS OF THE STATE, WITH 500-HPA HEIGHTS CLOSER
TO NORMAL WITHIN THE ARCTIC CIRCLE. NEAR-NORMAL HEIGHTS AND WEAK MID-LEVEL
FORCINGS ARE AGAIN FORECAST OVER HAWAII.
THE TRANSITION TO A MORE ZONAL MID-LEVEL FLOW PATTERN AND BROADLY ABOVE-NORMAL
500-HPA HEIGHTS FAVORS ELEVATED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES FOR
MOST OF THE CONUS, WITH THE HIGHEST PROBABILITIES PERSISTING ACROSS PORTIONS OF
SOUTHERN TEXAS AND FLORIDA. ONE EXCEPTION IS OVER THE MID-ATLANTIC REGION AND
PARTS OF THE CENTRAL APPALACHIANS, WHERE RAW AND REFORECAST TOOLS FROM THE
CANADIAN ENSEMBLES SHOW ODDS FAVORING NEAR-NORMAL OR ONLY SLIGHTLY ABOVE-NORMAL
TEMPERATURES DUE TO LINGERING INFLUENCE FROM THE NEGATIVE 500-HPA ANOMALIES
THAT ARE DISSIPATING EARLY WEEK-2. BELOW-NORMAL TEMPERATURE CHANCES ARE
INCREASED OVER SOUTHERN PORTIONS OF ALASKA, WITH ABOVE-NORMAL TEMPERATURE
CHANCES ENHANCED OVER THE NORTHERN AND CENTRAL MAINLAND, SIMILAR TO THE 6- TO
10-DAY FORECAST PERIOD GIVEN THE VERY SIMILAR MEAN MID-LEVEL FLOW PATTERN. WEAK
SURFACE AND MID-LEVEL FEATURES, WITH LOWER MID-LEVEL HEIGHTS AND HIGHER SURFACE
PRESSURE NORTHEAST OF THE ISLANDS, CONTINUE TO WEAKLY FAVOR SUBNORMAL
TEMPERATURES IN CENTRAL HAWAII, WITH SLIGHTLY INCREASING HEIGHTS AND
ABOVE-NORMAL SEA SURFACE TEMPERATURES TILTING THE ODDS SLIGHTLY TOWARD
ABOVE-NORMAL TEMPERATURES OVER THE SOUTHERN HALF OF THE BIG ISLAND.
INCREASED PROBABILITIES FOR BELOW-NORMAL PRECIPITATION ARE FAVORED ACROSS
PORTIONS OF THE CENTRAL AND NORTHEASTERN GULF COAST REGION, JUST SOUTH OF WEAK
SURFACE HIGH PRESSURE. RAW OUTPUT FROM THE ECMWF, CANADIAN, AND GEFS ENSEMBLE
MEANS ALL SHOW SUBNORMAL PRECIPITATION IN THIS REGION, WITH THE MOST LIMITED
EXTENT SHOWN BY THE FAVORED CANADIAN ENSEMBLE MEAN. THE REFORECAST TOOLS SHIFT
THE ENHANCED CHANCES FOR DRYNESS FARTHER SOUTH INTO THE GULF OF MEXICO, BUT THE
FORECAST PATTERN IS MORE CONSISTENT WITH DRYNESS EXTENDING FARTHER NORTH.
FARTHER WEST, SOUTHERLY SURFACE WINDS AND CONFLUENT SURFACE FLOW FAVOR PERIODS
OF ENHANCED RAINFALL DURING THE WEEK-2 PERIOD, WITH THE BEST ODDS (OVER 40
PERCENT) COVERING PORTIONS OF THE SOUTHERN PLAINS. WITH HIGH PRESSURE CENTERED
TO THE SOUTH AND EAST, SLIGHTLY ENHANCED CHANCES FOR SURPLUS PRECIPITATION
EXTEND NORTHEASTWARD ACROSS THE TENNESSEE AND SOUTHERN OHIO VALLEYS THROUGH
CENTRAL AND NORTHERN PORTIONS OF THE EASTERN SEABOARD. INCREASED TROPICAL
THUNDERSHOWER ACTIVITY ALSO INCREASES ODDS FOR ABOVE-NORMAL RAINFALL IN
SOUTHERN FLORIDA. TO THE WEST, THERE IS A SLIGHT TILT TOWARD ELEVATED
BELOW-NORMAL PRECIPITATION PROBABILITIES ACROSS THE NORTHERN INTERIOR WEST
UNDER A WEAK POSITIVE 500-HPA ANOMALY CENTER. THERE ARE ENHANCED CHANCES FOR
ABOVE-NORMAL PRECIPITATION ALONG MOST OF THE WEST COAST, UNDER A MOIST PACIFIC
AIR MASS AND SOME POTENTIAL INFLUENCE FROM THE STRONG TROUGHING CENTERED NEAR
SOUTHERN ALASKA. THIS TROUGHING CONTINUES TO FAVOR ENHANCED CHANCES FOR
ABOVE-NORMAL PRECIPITATION ACROSS MOST OF THE STATE. WEAK SURFACE WINDS AND A
NONDESCRIPT MID-LEVEL PATTERN SLIGHTLY FAVORS DRIER THAN NORMAL WEATHER ACROSS
HAWAII.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 15% OF TODAY'S GFS
SUPERENSEMBLE MEAN CENTERED ON DAY 11, 25% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 60% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO DECENT
AGREEMENT AMONG THE FORECAST TOOLS, OFFSET BY DECREASING PREDICTABILITY AND
MODEL DIVERGENCE LATER IN THE PERIOD AS THE MID-LEVEL PATTERN BECOMES MORE
ZONAL.
FORECASTER: RICH TINKER
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
JUNE 20.
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:
19990602 - 20030507 - 19660512 - 20020507 - 19620602
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:
20030507 - 19990604 - 19620527 - 19890518 - 19660515
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 30 - JUN 03, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON N N NRN CALIF A B
SRN CALIF N N IDAHO N B NEVADA A B
W MONTANA N B E MONTANA A N WYOMING A N
UTAH A B ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI N A
ARKANSAS A A LOUISIANA A N WISCONSIN A N
ILLINOIS N N MISSISSIPPI A N MICHIGAN N N
INDIANA N N OHIO B B KENTUCKY B B
TENNESSEE B B ALABAMA A B NEW YORK N B
VERMONT N B NEW HAMP N B MAINE A N
MASS B B CONN B B RHODE IS B B
PENN B B NEW JERSEY B B W VIRGINIA B B
MARYLAND B B DELAWARE B B VIRGINIA B B
N CAROLINA B B S CAROLINA B B GEORGIA N B
FL PNHDL A B FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN A A
AK S INT B A AK SO COAST B A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUN 01 - 07 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A A
SRN CALIF N N IDAHO A B NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A B
UTAH A N ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A B S DAKOTA A N
NEBRASKA A N KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A N IOWA A N MISSOURI A A
ARKANSAS A A LOUISIANA A N WISCONSIN A N
ILLINOIS A N MISSISSIPPI A N MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY A A
TENNESSEE A A ALABAMA A N 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 N NEW JERSEY N N W VIRGINIA N N
MARYLAND N N DELAWARE N N VIRGINIA N A
N CAROLINA N A S CAROLINA A N GEORGIA A N
FL PNHDL A B FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN A 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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