672
FXUS06 KWBC 091919
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 09 2025
6-10 DAY OUTLOOK FOR MAY 15 - 19 2025
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA
CIRCULATION PATTERN ACROSS NORTH AMERICA AND SURROUNDING REGIONS DURING THE
6-10 DAY PERIOD. THE MANUAL 500-HPA HEIGHT BLEND IS BASED ON MODEL HEIGHT
ANOMALY CORRELATION SCORES FOR THE PAST 60 DAYS. THE RESULTANT MANUAL BLEND
DEPICTS A WAVE NUMBER 5 PATTERN ACROSS THE NORTHERN HEMISPHERE. MOST RELEVANT
TO THE UNITED STATES ARE A STRONG ANOMALOUS (BUT FLAT) RIDGE OFF THE PACIFIC
COAST CENTERED NEAR 40N/140W WITH PREDICTED MAXIMUM POSITIVE HEIGHT ANOMALIES
NEAR +150 METERS, WEAK TO MODERATE ANOMALOUS RIDGING OVER THE ATLANTIC AND GULF
COAST STATES, A MODERATE TROUGH STRETCHING FROM THE NORTH-CENTRAL CONTIGUOUS
U.S. (CONUS) INTO THE SOUTHWEST, AND A WEAK TROUGH OVER ALASKA. AN ENHANCED
WESTERLY JET IS PREDICTED BETWEEN THE FLAT RIDGE OVER THE EASTERN PACIFIC AND
THE ALASKA TROUGH, WHICH FOCUSES ONSHORE FLOW AND INCREASED PRECIPITATION FROM
THE ALASKA PANHANDLE SOUTHWARD ACROSS THE PACIFIC NORTHWEST. NEAR NORMAL
500-HPA HEIGHTS AND ANOMALOUSLY WARM SEA SURFACE TEMPERATURES (SSTS) ARE
PREDICTED IN THE VICINITY OF THE HAWAIIAN ISLANDS.
ABOVE NORMAL TEMPERATURES ARE LIKELY FOR APPROXIMATELY THE EASTERN HALF OF THE
CONUS DUE TO A COMBINATION OF ANOMALOUS RIDGING OVER THE EAST AND WIDESPREAD
SOUTHERLY FLOW. THE HIGHEST LIKELIHOOD OF UNSEASONABLE WARMTH IS ACROSS EASTERN
PORTIONS OF THE CAROLINAS AND GEORGIA, WHERE PROBABILITIES EXCEED 70 PERCENT.
BELOW NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE WESTERN CONUS AS A STRONG
TROUGH IS FORECAST TO PROGRESS EASTWARD ACROSS THE REGION DURING THE PERIOD,
SUPPORTED BY MOST OF THE DYNAMICAL TEMPERATURE FORECAST TOOLS. A RELATIVELY
SMALL REGION OF FAVORED ABOVE NORMAL TEMPERATURES IS INDICATED FOR
NORTH-CENTRAL CALIFORNIA, BASED ON NEARLY ALL TEMPERATURE TOOLS. IN ALASKA, THE
AUTO BLEND TEMPERATURE FORECAST APPEARS TO BE TOO COLD OVERALL AND THE OFFICIAL
FORECAST IS MORE CONSISTENT WITH THE ERF CONSOLIDATION AND ECENS
REFORECAST-CALIBRATED TEMPERATURE TOOLS, WHICH FAVOR BELOW NORMAL TEMPERATURES
OVER FAR NORTHERN ALASKA AND MOST OF THE PANHANDLE REGION. ABOVE NORMAL
TEMPERATURES ARE FAVORED OVER SOUTHWESTERN PORTIONS OF THE MAINLAND, THE ALASKA
PENINSULA, AND THE ALEUTIANS. NEAR NORMAL TEMPERATURES ARE FAVORED OVER A LARGE
FRACTION OF THE STATE DUE TO WEAK OR CONFLICTING GUIDANCE. ABOVE NORMAL
TEMPERATURES ARE LIKELY ACROSS HAWAII CONSISTENT WITH ANTICIPATED ABOVE NORMAL
SEA SURFACE TEMPERATURES (SSTS) IN ADJACENT WATERS.
MUCH OF THE LOWER 48 STATES ARE FAVORED TO HAVE A SLIGHT TILT IN THE ODDS
TOWARDS WETTER THAN NORMAL CONDITIONS DURING THE 6-10 DAY PERIOD. THIS IS
CONSISTENT WITH NEARLY ALL PRECIPITATION GUIDANCE, AND IS CONSISTENT WITH
WIDESPREAD MOIST SOUTHERLY FLOW FROM THE GULF INTERACTING WITH A BROAD
BAROCLINIC ZONE AND SEVERAL SURFACE LOW PRESSURE AREAS, AND A MID-LEVEL TROUGH
APPROACHING FROM THE WEST. BELOW NORMAL PRECIPITATION IS FAVORED ALONG THE GULF
COAST REGION AND OVER CENTRAL PORTIONS OF THE WEST COAST, SUPPORTED BY NEARLY
ALL OF THE PRECIPITATION TOOLS. IN ALASKA, ABOVE NORMAL PRECIPITATION CHANCES
ARE ELEVATED ACROSS MOST OF CENTRAL AND SOUTHERN PORTIONS OF THE STATE, WITH
NEAR TO BELOW NORMAL PRECIPITATION FAVORED OVER MOSTLY NORTHERN AREAS OF THE
STATE. ABOVE NORMAL PRECIPITATION IS FAVORED FOR HAWAII, CONSISTENT WITH SKILL
WEIGHTED CALIBRATED PRECIPITATION AMOUNTS CALCULATED FROM THE GEFS AND ECMWF
ENSEMBLES.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 25% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 30% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: 4 ON A SCALE OF 1-5, AND BASED ON
FAIRLY GOOD AGREEMENT AMONG THE FORECAST GUIDANCE.
8-14 DAY OUTLOOK FOR MAY 17 - 23 2025
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A FLATTER, MORE RELAXED
500-HPA CIRCULATION PATTERN RELATIVE TO THE 6-10 DAY PERIOD ACROSS NORTH
AMERICA AND THE SURROUNDING REGIONS. THE WEEK-2 PERIOD FEATURES ANOMALOUS
RIDGING AND ABOVE NORMAL 500-HPA HEIGHTS OVER THE EASTERN PACIFIC OCEAN,
BROADLY CENTERED NEAR 40N/140W, WITH THE MANUAL HEIGHT BLEND PREDICTING MAXIMUM
POSITIVE HEIGHT ANOMALIES RANGING FROM 90-120 METERS. THE EASTERN CONUS RIDGE
IS FORECAST TO BECOME MORE ZONALLY ORIENTED ACROSS MUCH OF TEXAS AND THE GULF
COAST STATES. A WEAK, RELATIVELY FLAT TROUGH IS DEPICTED FROM THE VICINITY OF
THE NORTHERN AND CENTRAL PLAINS EAST-NORTHEASTWARD INTO THE GREAT LAKES REGION.
IN ALASKA, A WEAK TROUGH IS PREDICTED, WITH MID-LEVEL HEIGHT RISES (RELATIVE TO
THE EARLIER 6-10 DAY PERIOD) EXPECTED OVER THE ALEUTIANS AND ALASKA PENINSULA.
FOR THE FORECAST DOMAIN, THE DYNAMICAL MODELS ARE GENERALLY IN GOOD AGREEMENT
WITH RESPECT TO PHASE, WITH SOME DIFFERENCES APPARENT WITH RESPECT TO AMPLITUDE
OF LONGER WAVELENGTH FEATURES. NEAR TO SLIGHTLY BELOW NORMAL 500-HPA HEIGHTS
ARE FORECAST FOR HAWAII, WELL TO THE SOUTH OF THE MEAN RIDGE FORECAST ACROSS
THE EASTERN PACIFIC.
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE SOUTHERN TWO-THIRDS OF
THE CONUS, CONTINUING ACROSS THE EASTERN GREAT LAKES REGION AND NORTHEAST, WITH
MAXIMUM PROBABILITIES FAVORING ABOVE NORMAL TEMPERATURES OF 60-70 PERCENT OVER
THE FLORIDA PENINSULA. THIS IS BROADLY ATTRIBUTED TO A WEAK MID-LEVEL HEIGHT
ANOMALY PATTERN, AND A RAPIDLY WEAKENING TROUGH MOVING ACROSS THE NORTH-CENTRAL
STATES AND GREAT LAKES. THE PATTERN IS ALSO SUPPORTED BY THE AUTO BLEND AND
CONSOLIDATED TEMPERATURE FORECASTS. BELOW NORMAL TEMPERATURE CHANCES ARE
SLIGHTLY ELEVATED ACROSS THE NORTHERN TIER OF STATES FROM WASHINGTON EASTWARD
TO MINNESOTA, ASSOCIATED WITH THE WEAKENING MID-LEVEL TROUGH. THE WEEK-2 ALASKA
AND HAWAII TEMPERATURE OUTLOOKS ARE VERY SIMILAR TO THEIR 6-10 DAY
COUNTERPARTS, ACCOMPANIED BY SIMILAR REASONING.
THE WEEK-2 PRECIPITATION OUTLOOK CALLS FOR A SLIGHT TILT TOWARDS ABOVE NORMAL
PRECIPITATION OVER A LARGE PORTION OF THE LOWER 48 STATES, SIMILAR TO THE
EARLIER 6-10 DAY PERIOD, AND IS SUPPORTED BY MOST OF THE PRECIPITATION
GUIDANCE. BELOW NORMAL PRECIPITATION IS FAVORED OVER CENTRAL AND SOUTHERN
PORTIONS OF THE PACIFIC COAST, EXTREME SOUTHERN TEXAS, AND MOST OF FLORIDA,
PRIMARILY DUE TO THESE AREAS BEING SUFFICIENTLY REMOVED FROM THE PRIMARY STORM
TRACK. THE PRECIPITATION OUTLOOKS FOR ALASKA AND HAWAII ARE MOSTLY FAVORED TO
BE WETTER THAN NORMAL, SIMILAR TO THE EARLIER 6-10 DAY OUTLOOKS, WITH THE MAIN
DIFFERENCE BEING THE PREDICTED ANOMALOUS WETNESS OVER NORTHERN ALASKA IN THE
WEEK-2 PERIOD.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 45% 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: 3 ON A SCALE OF 1-5, DUE TO
GENERALLY GOOD AGREEMENT AMONG MODEL GUIDANCE, OFFSET BY UNCERTAINTIES
ASSOCIATED WITH A PREDICTED FLATTENING FLOW PATTERN.
FORECASTER: ANTHONY A
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
15.
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:
19870505 - 19870421 - 19780515 - 20060429 - 19570428
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:
19780515 - 19870420 - 19870505 - 19880522 - 19980426
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 15 - 19 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B N NRN CALIF A B
SRN CALIF N N IDAHO B A NEVADA B N
W MONTANA B A E MONTANA B A WYOMING B A
UTAH B A ARIZONA B A COLORADO B A
NEW MEXICO B N N DAKOTA B A S DAKOTA N A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A N W TEXAS A A
MINNESOTA A 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 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 N GEORGIA A N
FL PNHDL A B FL PENIN A B AK N SLOPE B N
AK ALEUTIAN A A AK WESTERN A A AK INT BSN N A
AK S INT N A AK SO COAST N A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 17 - 23 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON N B NRN CALIF A B
SRN CALIF A B IDAHO N N NEVADA A B
W MONTANA B N E MONTANA B A WYOMING N A
UTAH A A ARIZONA A A COLORADO N A
NEW MEXICO A N N DAKOTA B A S DAKOTA N A
NEBRASKA N A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A N W TEXAS A A
MINNESOTA N A IOWA N A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN N A
ILLINOIS A A MISSISSIPPI A A MICHIGAN N 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 N FL PENIN A B AK N SLOPE N N
AK ALEUTIAN A N AK WESTERN A A AK INT BSN N A
AK S INT N A AK SO COAST N 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.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page