607
FXUS06 KWBC 181902
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 18 2026
6-10 DAY OUTLOOK FOR MAY 24 - 28 2026
POSITIVE 500-HPA HEIGHT ANOMALIES ARE FORECAST ACROSS MUCH OF EASTERN NORTH
AMERICA DURING THE 6-10 DAY PERIOD. CORRESPONDING STRONG MID-LEVEL RIDGING IS
FAVORED OVER THE EASTERN CONTIGUOUS U.S. (CONUS) DURING THE PERIOD. OVER
ALASKA, MID-LEVEL TROUGHING AND NEGATIVE 500-HPA HEIGHT ANOMALIES ARE FAVORED
WITH POSITIVE 500-HPA HEIGHT ANOMALIES FORECAST TO THE SOUTH. THIS MAY SET UP
ENHANCED ONSHORE FLOW AT THE MID-LEVELS INTO PARTS OF WESTERN NORTH AMERICA.
UNFORTUNATELY, THERE ARE SIGNIFICANT DIFFERENCES AMONG THE TOOLS REGARDING THE
DEVELOPMENT OF A MID-LEVEL TROUGH (ECENS) OR EXPANDED POSITIVE 500-HPA HEIGHT
ANOMALIES (GEFS AND CMCE) ALONG THE WEST COAST. THE EVOLUTION OF THE MID-LEVEL
PATTERN IN THIS REGION WILL INFLUENCE THE FORECAST. AT THIS TIME, THE MANUAL
BLEND FAVORS A WEAK TROUGH OVER THIS REGION BUT IS MORE OF A COMPROMISE BETWEEN
THESE TO DIVERGING SOLUTIONS.
AS A RESULT OF THE DIFFERENCES BETWEEN THE MID-LEVEL HEIGHT FORECASTS, THERE IS
MORE UNCERTAINTY ACROSS THE WEST COAST FOR THE PERIOD AVERAGE TEMPERATURES. AS
A RESULT, NEAR NORMAL TEMPERATURES ARE FAVORED ALONG THE WEST COAST. A SEPARATE
AREA OF NEAR NORMAL TEMPERATURES IS FAVORED OVER PARTS OF THE SOUTHWEST AND
TEXAS. THIS IS A REGION THAT IS STRONGLY FAVORED TO SEE ABOVE NORMAL
PRECIPITATION WHICH IS MOST LIKELY TO BRING NEAR NORMAL TEMPERATURES. ACROSS
THE REST OF THE CONUS, ABOVE NORMAL TEMPERATURES ARE FAVORED WITH MID-LEVEL
RIDGING AND POSITIVE 500-HPA HEIGHT ANOMALIES FORECAST. BELOW NORMAL
TEMPERATURES ARE FAVORED IN ALASKA, WITH MID-LEVEL TROUGHING OVER THE STATE.
CHANCES FOR BELOW NORMAL INCREASE TOWARDS SOUTHERN ALASKA. IN HAWAII, ABOVE
NORMAL TEMPERATURES ARE FAVORED FOR THE EASTERN ISLANDS, WHILE NEAR NORMAL
TEMPERATURES ARE FAVORED FOR OAHU AND KAUAI.
ABOVE NORMAL PRECIPITATION IS GENERALLY FAVORED FROM NEAR AND ALONG THE ROCKIES
THROUGH THE EAST COAST DURING THE PERIOD. THERE IS STRONG MODEL AGREEMENT FOR
ABOVE NORMAL PRECIPITATION OVER THE FOUR CORNERS REGION, SOUTHERN PLAINS, AND
LOWER MISSISSIPPI VALLEY. CORRESPONDING TO THE STRONGEST AND MOST CONSISTENT
CHANCES IN THE TOOLS IS A 60% CHANCE OF ABOVE NORMAL FOR THE RIO GRANDE VALLEY.
GUIDANCE SUGGESTS THAT ELEVATED PRECIPITATION CHANCES COULD POTENTIALLY EXTEND
FROM THE PLAINS THROUGH THE EAST COAST DURING THE PERIOD. WHILE THE ECENS
SOLUTIONS ARE MOST AGGRESSIVE WITH THIS PATTERN, SUPPORT FROM THE GEFS REMAINS
SOMEWHAT LIMITED. NEVERTHELESS, AS ANALOG TOOLS REMAIN GENERALLY SUPPORTIVE OF
THIS EVOLUTION, A 40-50% PROBABILITY OF ABOVE NORMAL PRECIPITATION IS FAVORED
FOR THIS REGION. THERE ARE REDUCED CHANCES FOR ABOVE NORMAL PRECIPITATION OVER
THE NORTHERN PLAINS, GREAT LAKES, AND NORTHEAST, RELATIVE TO REGIONS FURTHER
SOUTH. IN THE WEST, UNCERTAINTY REGARDING THE MID-LEVEL PATTERN AND DIFFERENCES
AMONG THE PRECIPITATION GUIDANCE SUPPORT NEAR NORMAL PRECIPITATION. IN ALASKA,
WITH MID-LEVEL TROUGHING OVER THE STATE, ABOVE NORMAL PRECIPITATION IS
FORECAST. IN HAWAII, ABOVE NORMAL PRECIPITATION CONTINUES TO BE FAVORED
CONSISTENT WITH MODEL GUIDANCE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 25% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 50% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 25% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, AVERAGE TOOL
AGREEMENT IS OFFSET BY DIFFERENCES IN THE EVOLUTION OF THE PATTERN OVER THE
WESTERN U.S.
8-14 DAY OUTLOOK FOR MAY 26 - JUN 01, 2026
POSITIVE 500-HPA HEIGHT ANOMALIES AND MID-LEVEL RIDGING ARE FAVORED OVER MOST
OF EASTERN NORTH AMERICA DURING WEEK-2. THERE CONTINUES TO BE SOME DIFFERENCES
AMONG THE TOOLS OVER THE WESTERN CONUS REGARDING THE EVOLUTION OF THE MID-LEVEL
HEIGHTS BUT THERE IS GENERALLY BETTER AGREEMENT FOR A WEAK TROUGH. IN ALASKA,
MID-LEVEL TROUGHING IS WEAKENING FROM THE 6-10 DAY PERIOD AND YESTERDAY'S
FORECAST, SUCH THAT BY THE END OF WEEK-2, NEGATIVE ANOMALIES HAVE BEEN MOSTLY
ERODED. OVER HAWAII, NEAR NORMAL 500-HPA HEIGHTS REMAIN FAVORED.
ABOVE NORMAL TEMPERATURES ARE FAVORED OVER MOST OF THE CONUS DURING WEEK-2. THE
STRONGEST CHANCES ARE OVER THE NORTHERN PLAINS, UPPER MISSISSIPPI VALLEY, AND
GREAT LAKES. NEAR NORMAL TEMPERATURES ARE FAVORED OVER PARTS OF NEW MEXICO AND
TEXAS WHERE ENHANCED PRECIPITATION MAY LIMIT TEMPERATURES. MEANWHILE, ALONG THE
IMMEDIATE COAST OF NORTHERN CALIFORNIA, OREGON, AND WASHINGTON, NEAR NORMAL IS
FAVORED WITH SOME UNCERTAINTY REGARDING THE MID-LEVEL HEIGHT PATTERN OVER THE
REGION. IN ALASKA, BELOW NORMAL TEMPERATURES REMAIN FAVORED, WITH THE STRONGEST
CHANCES INCREASING TOWARDS SOUTHERN ALASKA. MUCH OF THIS IS LIKELY FRONT LOADED
WITH TEMPERATURE ANOMALIES DECREASING OVER TIME. IN HAWAII, ABOVE NORMAL
TEMPERATURES ARE FAVORED OVER THE STATE.
ABOVE NORMAL PRECIPITATION REMAINS FAVORED FROM THE FOUR CORNERS REGION
EASTWARD TO THE SOUTHERN MID-ATLANTIC AND SOUTHEAST. FORECAST GUIDANCE
CONTINUES TO SUPPORT ELEVATED CHANCES FOR ABOVE NORMAL PRECIPITATION IN THIS
REGION. THE BEST MODEL SUPPORT IS OVER THE EASTERN FOUR CORNERS AND SOUTHERN
PLAINS WITH LOWER CHANCES FURTHER TOWARDS THE SOUTHEAST AND MID-ATLANTIC. THERE
COULD BE A RELATIVELY QUICK FLIP IN PROBABILITIES IN THIS REGION AS
PRECIPITATION TIMES OFF IN THE NEXT FEW DAYS. BELOW NORMAL PRECIPITATION IS
FORECAST FOR THE GREAT LAKES AND NORTHEAST CONSISTENT WITH THE POSITIVE 500-HPA
HEIGHT ANOMALIES OVER EASTERN U.S. BELOW NORMAL PRECIPITATION IS ALSO FORECAST
OVER THE PACIFIC NORTHWEST CONSISTENT WITH THE STATISTICAL GUIDANCE. FINALLY, A
SMALL AREA OF ABOVE NORMAL PRECIPITATION IS FAVORED OVER PARTS OF THE NORTHERN
PLAINS CONSISTENT WITH DYNAMICAL PRECIPITATION GUIDANCE. IN ALASKA, ABOVE
NORMAL IS FAVORED FOR SOUTHERN AND EASTERN MAINLAND AND SOUTHEAST ALASKA. IN
HAWAII, ABOVE NORMAL PRECIPITATION IS FAVORED ACROSS THE ISLANDS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% 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: AVERAGE, 3 OUT OF 5, GOOD
CONSISTENCY AMONG THE TOOLS IS OFFSET BY DIFFERENCES IN HOW THE PATTERN WILL
EVOLVE ACROSS THE WESTERN U.S.
FORECASTER: RYAN BOLT
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 MAY
21.
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:
20240531 - 20060506 - 20250501 - 20110505 - 20170501
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:
20240531 - 20250501 - 20070427 - 20180507 - 20060506
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 24 - 28 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON N N NRN CALIF N N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A N E MONTANA A N WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO N A N DAKOTA A N S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS N A S TEXAS N A W TEXAS N A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A N
ILLINOIS A A MISSISSIPPI A A MICHIGAN A N
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 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 26 - JUN 01, 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A N E MONTANA A N WYOMING A A
UTAH A A ARIZONA A N COLORADO A A
NEW MEXICO N A N DAKOTA A A S DAKOTA A N
NEBRASKA A N KANSAS A A OKLAHOMA A A
N TEXAS N A S TEXAS N A W TEXAS N A
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A A LOUISIANA A A WISCONSIN A N
ILLINOIS A N MISSISSIPPI A A MICHIGAN A B
INDIANA A N OHIO A B KENTUCKY A N
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 A N VIRGINIA A N
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A A AK N SLOPE B N
AK ALEUTIAN B A AK WESTERN B N AK INT BSN B 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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