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FXUS06 KWBC 211902
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 21 2026
6-10 DAY OUTLOOK FOR MAY 27 - 31 2026
DYNAMICAL MODELS ARE IN GOOD AGREEMENT REGARDING THE 500-HPA HEIGHT PATTERN
ACROSS NORTH AMERICA AT THE START OF THE 6-10 DAY FORECAST PERIOD, BUT BEGIN TO
DIVERGE TOWARD DAY-10. AN ANOMALOUS MID-LEVEL RIDGE (+180 METER POSITIVE HEIGHT
ANOMALY CENTER) IS PREDICTED ACROSS CENTRAL CANADA WITH POSITIVE 500-HPA HEIGHT
ANOMALIES EXTENDING SOUTHWARD INTO MUCH OF THE NORTHERN AND EASTERN CONUS IN
THE MANUAL HEIGHT BLEND. TROUGHS ARE FORECAST ON EITHER SIDE OF THIS RIDGE
AXIS, ACROSS SOUTHERN ALASKA AND OVER THE NORTHWESTERN ATLANTIC, WITH
BELOW-NORMAL HEIGHTS TIED TO THESE FEATURES. ADDITIONAL SHORTWAVE TROUGHING AND
AN ASSOCIATED CLOSED LOW ARE FORECAST ACROSS THE SOUTHWESTERN CONUS EARLY IN
THE FORECAST PERIOD FAVORING NEAR-NORMAL MID-LEVEL HEIGHTS FOR THE PERIOD AS A
WHOLE. THE 0Z ECMWF AND CANADIAN ENSEMBLES PERSIST THE STRONG RIDGE ACROSS
CANADA THROUGHOUT THE PERIOD, WHILE THE 0Z GEFS IS FASTER TO WEAKEN AND BROADEN
THIS FEATURE ACROSS MUCH OF THE NORTHERN CONUS. HOWEVER, RECENT SKILL SUPPORTS
A LEAN TOWARD THE MORE AMPLIFIED ECMWF AND CANADIAN SOLUTIONS. NEAR NORMAL
MID-LEVEL HEIGHTS AND SOUTHEASTERLY LOW-LEVEL FLOW ARE FORECAST ACROSS HAWAII.
THE HIGHEST CONFIDENCE IN THE TEMPERATURE OUTLOOK REMAINS ACROSS PORTIONS OF
THE NORTHERN AND CENTRAL PLAINS INTO THE MIDWEST UNDERNEATH THE HIGH AMPLITUDE
MID-LEVEL RIDGE PREDICTED ACROSS CANADA. PROBABILITIES FOR ABOVE-NORMAL
TEMPERATURES EXCEED 80 PERCENT OVER PORTIONS OF THE UPPER MISSISSIPPI VALLEY.
HOWEVER, UNCERTAINTY INCREASES FARTHER SOUTH, AS RIDGING BECOMES LESS
INFLUENTIAL AND ENHANCED PRECIPITATION AND CLOUD COVER SUPPORTS LESS ANOMALOUS
TEMPERATURES. THE UNCALIBRATED 0Z ECMWF ENSEMBLE DEPICTS ELEVATED CHANCES OF
BELOW-NORMAL TEMPERATURES ACROSS MUCH OF THE SOUTHERN TIER, EXTENDING INTO
PORTIONS OF THE TENNESSEE VALLEY AND MID-ATLANTIC. ITS CORRESPONDING REFORECAST
TOOL ALSO SHOWS A MORE EXPANSIVE AREA OF NEAR-NORMAL TEMPERATURES COMPARED TO
YESTERDAY, WITH A SIMILAR, BUT NOT AS PRONOUNCED SIGNAL, IN THE CANADIAN
REFORECAST TOOL. ANALOG GUIDANCE ALSO SUPPORTS A LEAN TOWARD COOLER
TEMPERATURES. THEREFORE, PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ARE LARGELY
REDUCED ACROSS THE SOUTHERN AND SOUTHEASTERN CONUS RELATIVE TO YESTERDAY, WITH
NEAR-NORMAL TEMPERATURES NOW BEING FAVORED OVER MANY AREAS AND A SLIGHT TILT
TOWARD ENHANCED CHANCES OF BELOW-NORMAL TEMPERATURES ACROSS PARTS OF THE
SOUTHERN PLAINS. FLORIDA CONTINUES TO TILT TOWARD ABOVE-NORMAL TEMPERATURES
TIED TO WEAK SUBTROPICAL RIDGING OVER THE SOUTHWESTERN ATLANTIC EARLY IN THE
PERIOD. A TRANSITIONAL TEMPERATURE PATTERN IS PREDICTED ACROSS THE WESTERN
CONUS, WITH GENERALLY COOLER TEMPERATURES UNDERNEATH A CLOSED MID-LEVEL LOW
EARLY IN THE PERIOD, FOLLOWED BY A WARMING TREND LATE AS THE FEATURE WEAKENS.
THIS GENERALLY SUPPORTS NEAR- TO SLIGHTLY BELOW-NORMAL TEMPERATURES OVER MOST
OF THE WEST. PERSISTENT CYCLONIC FLOW LEADS TO ELEVATED CHANCES OF BELOW-NORMAL
TEMPERATURES ACROSS MOST OF ALASKA. ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR
MOST OF HAWAII, ASSOCIATED WITH OBSERVED ABOVE-NORMAL SSTS IN THE ADJACENT
PACIFIC.
SHORTWAVE TROUGHING INITIALLY PREDICTED ACROSS THE SOUTHWESTERN CONUS FAVORS
ENHANCED SOUTHERLY MOISTURE FLOW FROM THE GULF, WITH MUCH OF THE MOISTURE
BECOMING TRAPPED UNDERNEATH THE RIDGE TO THE NORTH. THIS FAVORS A WET PATTERN
PERSISTING ALONG THE GULF COAST, EXTENDING INTO PORTIONS OF THE TENNESSEE
VALLEY, SOUTHEAST, AND MID-ATLANTIC AT LEAST INTO THE EARLY PART OF THE
FORECAST PERIOD. ABOVE-NORMAL PRECIPITATION PROBABILITIES ARE ALSO ELEVATED
ACROSS MUCH OF THE WESTERN CONUS INTO THE GREAT PLAINS. BY THE SECOND HALF OF
THE PERIOD, MODELS DEPICT DIMINISHING PRECIPITATION SIGNALS AS THE
AFOREMENTIONED TROUGH OVER THE SOUTHWEST WEAKENS. CONVERSELY, CHANCES FOR
BELOW-NORMAL PRECIPITATION ARE INCREASED ACROSS PORTIONS OF THE UPPER
MISSISSIPPI VALLEY, GREAT LAKES, AND NORTHEAST TIED TO RIDGING ALONG WITH
SUPPORT FROM THE ECMWF AND GEFS REFORECAST GUIDANCE AND ANALOGS. AN ACTIVE
PATTERN IS FAVORED FOR MOST OF ALASKA UNDERNEATH PREDICTED CYCLONIC FLOW.
CONFIDENCE IS HIGHEST (GREATER THAN 40 PERCENT CHANCE) FOR ABOVE-NORMAL
PRECIPITATION ACROSS PARTS OF THE EASTERN MAINLAND AND SOUTHEAST ALASKA, AS
PREDICTED CYCLONIC FLOW PROMOTES ENHANCED ONSHORE FLOW. A WEAK TILT TOWARD
ABOVE NORMAL PRECIPITATION IS INDICATED FOR HAWAII, CONSISTENT WITH A SKILL
WEIGHTED CONSOLIDATION OF CALIBRATED PRECIPITATION AMOUNTS FROM THE ECMWF AND
GEFS ENSEMBLES.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 35% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 35% 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 DECENT
MODEL AGREEMENT EARLY IN THE PERIOD, BUT OFFSET BY INCREASING SPREAD WITH TIME,
ALONG WITH SOME MIXED SIGNALS REGARDING THE TEMPERATURE OUTLOOK OVER THE
WESTERN AND SOUTHERN CONUS.
8-14 DAY OUTLOOK FOR MAY 29 - JUN 04, 2026
DURING THE WEEK-2 PERIOD, AMPLIFIED RIDGING INITIALLY ACROSS CENTRAL CANADA IS
FORECAST TO BROADEN AND RETROGRADE SLIGHTLY TOWARD WESTERN CANADA AND THE
NORTHWESTERN CONUS, WITH THE 0Z GEFS BEING QUICKER WITH THIS EVOLUTION COMPARED
TO THE 0Z ECMWF AND CANADIAN ENSEMBLES. AS A RESULT OF THE BROADER RIDGE AXIS,
POSITIVE 500-HPA HEIGHT ANOMALIES OF AT LEAST +30 METERS ARE INDICATED ACROSS
THE NORTHERN TWO-THIRDS OF THE CONUS IN THE MANUAL HEIGHT BLEND, INCREASING TO
GREATER THAN +90 METERS ACROSS THE UPPER MIDWEST AND NORTHERN PLAINS. A
WEAKNESS REMAINS FAVORED ACROSS THE SOUTHERN TIER AND ALONG THE GULF COAST AND
SOUTHEAST WHERE NEAR-NORMAL HEIGHTS ARE FORECAST. TROUGHING OVER SOUTHERN
ALASKA AND THE NORTHEASTERN PACIFIC FAVORS ENHANCED CYCLONIC FLOW OVER WESTERN
NORTH AMERICA EARLY IN THE PERIOD. HOWEVER, THIS TROUGH IS FORECAST TO SLOWLY
RETROGRADE TOWARD THE ALEUTIANS WITH TIME AS THE UPSTREAM RIDGE EXPANDS
WESTWARD, LEADING TO INCREASING HEIGHTS OVER THE WESTERN CONUS BY THE MIDDLE OF
THE PERIOD, AND NEAR-TO ABOVE-NORMAL HEIGHTS ACROSS MUCH OF ALASKA. NEAR NORMAL
HEIGHTS CONTINUE TO BE FORECAST ACROSS HAWAII.
ABOVE-NORMAL TEMPERATURES PROBABILITIES ARE FORECAST TO INCREASE OVER THE
WESTERN CONUS DURING WEEK-2 AS THE MEAN RIDGING RETROGRADES, WITH STRONGER
SIGNALS FOR WARMER TEMPERATURES RELATIVE TO THE 6-10 DAY PERIOD IN THE
DYNAMICAL MODELS SUPPORTING PROBABILITIES ABOVE 40 PERCENT EXTENDING TO THE
PACIFIC COAST. THE BROAD RIDGE AXIS ALSO FAVORS ELEVATED CHANCES OF
ABOVE-NORMAL TEMPERATURES OVER MUCH OF THE EASTERN AND NORTHERN CONUS. AREAS OF
THE COASTAL MID-ATLANTIC, SOUTHERN PLAINS, AND LOWER MISSISSIPPI VALLEY
MAINTAIN A TILT TOWARD NEAR- TO SLIGHTLY BELOW-NORMAL TEMPERATURES BASED ON THE
ANALOGS AND A LINGERING OF THE WETTER PATTERN DISCUSSED IN THE 6-10 DAY PERIOD
INTO WEEK-2. TROUGHING RETROGRADING ACROSS SOUTHERN ALASKA FAVORS ELEVATED
CHANCES OF BELOW NORMAL TEMPERATURES ACROSS THE SOUTHERN MAINLAND, SOUTHEAST
ALASKA, AND PARTS OF THE ALEUTIANS. NEAR- TO ABOVE-NORMAL TEMPERATURES ARE MORE
LIKELY ACROSS THE NORTHERN HALF OF THE MAINLAND TIED TO INCREASING MID-LEVEL
HEIGHTS. ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR HAWAII, ASSOCIATED WITH
OBSERVED ABOVE-NORMAL SSTS IN THE ADJACENT PACIFIC.
ABOVE-NORMAL PRECIPITATION REMAINS FAVORED ACROSS MUCH OF THE INTERIOR WESTERN
CONUS, GREAT PLAINS, AND INTO THE SOUTHEASTERN QUADRANT TIED TO A CONTINUED
WEAKNESS IN THE 500-HPA HEIGHT FIELD UNDERNEATH THE RIDGING TO THE NORTH AND
LINGERING RETURN FLOW OUT OF THE GULF. RELATIVE TO THE 6-10 DAY PERIOD, THERE
IS A NOTABLE EASTWARD SHIFT IN THE STRONGEST PRECIPITATION SIGNALS TOWARD
PORTIONS OF THE SOUTHEAST AND FLORIDA WHERE PROBABILITIES FOR ABOVE-NORMAL
PRECIPITATION HAVE BEEN INCREASED ABOVE 50 PERCENT OVER SOME AREAS. SURFACE
HIGH PRESSURE CONTINUES TO FAVOR INCREASED ODDS FOR BELOW-NORMAL PRECIPITATION
ACROSS THE GREAT LAKES AND NORTHEAST. A DRYING TREND IS ALSO LIKELY ACROSS THE
WEST COAST AS RIDGING EXPANDS INTO THE REGION, WITH NEAR- TO BELOW-NORMAL
PRECIPITATION BECOMING FAVORED ACROSS PORTIONS OF CALIFORNIA, THE PACIFIC
NORTHWEST, AND THE NORTHERN GREAT BASIN. NEAR TO ABOVE-NORMAL PRECIPITATION IS
FAVORED FOR ALASKA, UNDERNEATH PREDICTED MEAN CYCLONIC FLOW. A WEAK TILT TOWARD
ABOVE-NORMAL PRECIPITATION IS INDICATED FOR HAWAII, CONSISTENT WITH A SKILL
WEIGHTED CONSOLIDATION OF CALIBRATED PRECIPITATION AMOUNTS FROM THE ECMWF AND
GEFS ENSEMBLES.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 35% 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 GOOD
MODEL AGREEMENT REGARDING THE MID-LEVEL PATTERN EVOLUTION, OFFSET BY
DIMINISHING SIGNALS REGARDING TEMPERATURE AND PRECIPITATION.
FORECASTER: THOMAS COLLOW
NOTES:
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 (GRAY, "N") NORMAL.
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 (GRAY, "N")
NORMAL. 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 18.
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:
20250515 - 20200523 - 19910528 - 20170501 - 20250604
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:
20120528 - 20250501 - 20250515 - 19910528 - 20060506
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 27 - 31 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON N N NRN CALIF N N
SRN CALIF N N IDAHO A A NEVADA N A
W MONTANA A A E MONTANA A A WYOMING A A
UTAH N A ARIZONA N N COLORADO A A
NEW MEXICO B A N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA N A
N TEXAS N A S TEXAS N A W TEXAS B A
MINNESOTA A N IOWA A A MISSOURI A A
ARKANSAS N A LOUISIANA N A WISCONSIN A N
ILLINOIS A N MISSISSIPPI N A MICHIGAN A B
INDIANA A N OHIO A N KENTUCKY A A
TENNESSEE N A ALABAMA N A NEW YORK A B
VERMONT A B NEW HAMP A B MAINE A B
MASS A B CONN A B RHODE IS A B
PENN A B NEW JERSEY A B W VIRGINIA A N
MARYLAND A N DELAWARE N N VIRGINIA N N
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL N A FL PENIN A A AK N SLOPE B A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A
AK S INT B A AK SO COAST B A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 29 - JUN 04, 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A N NEVADA A A
W MONTANA A N E MONTANA A A WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO N A N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA N A
N TEXAS N A S TEXAS N A W TEXAS N A
MINNESOTA A N IOWA A N MISSOURI A A
ARKANSAS A A LOUISIANA N A WISCONSIN A N
ILLINOIS A N MISSISSIPPI A A MICHIGAN A B
INDIANA A N OHIO A N KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A B
VERMONT A B NEW HAMP A B MAINE A B
MASS A B CONN A B RHODE IS A B
PENN A B NEW JERSEY A B W VIRGINIA A N
MARYLAND A N DELAWARE N N VIRGINIA A N
N CAROLINA N 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 N AK INT BSN N A
AK S INT B A AK SO COAST B A 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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