858
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 THU AUGUST 14 2025
6-10 DAY OUTLOOK FOR AUG 20 - 24 2025
THE GEFS, ECENS, AND CMCE REMAIN CONSISTENT AND IN GOOD AGREEMENT THAT
ANOMALOUS MID-LEVEL RIDGING SHIFTS WESTWARD OVER THE NORTHERN ATLANTIC EARLY
NEXT WEEK. THE MANUAL BLEND DEPICTS POSITIVE 500-HPA HEIGHT ANOMALIES OF NEAR
200 METERS OVER GREENLAND, WHICH IS UNUSUALLY LARGE FOR AUGUST. THIS ANOMALOUS
RIDGE COUPLED WITH A WELL-ESTABLISHED STRONG RIDGE CENTERED ACROSS WESTERN
NORTH AMERICA IS FORECAST TO RESULT IN A DEEPENING 500-HPA TROUGH NEAR THE EAST
COAST AND WILL LIKELY STEER THE FUTURE TRACK OF TROPICAL STORM ERIN. THE
UNCALIBRATED ECENS DEPICT NEAR NORMAL TEMPERATURES FOR THE EAST COAST, WHILE
TEMPERATURES RANGE FROM BELOW (NORTHEAST) TO ABOVE (SOUTHEAST) IN THE GEFS.
THESE TEMPERATURE DIFFERENCES ARE RELATED TO HOW FAST TEMPERATURES COOL FROM
DAYS 6-8. NEAR TO BELOW-NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHEAST,
MID-ATLANTIC, AND GREAT LAKES WITH ABOVE-NORMAL TEMPERATURE PROBABILITIES
INCREASING CLOSER TO THE GULF COAST AND FLORIDA. FOR THE WESTERN HALF OF THE
CONUS, ABOVE-NORMAL TEMPERATURES ARE LIKELY DUE TO THE AMPLIFIED RIDGE OVER THE
WEST. ABOVE-NORMAL TEMPERATURE PROBABILITIES EXCEED 70 PERCENT ACROSS THE GREAT
BASIN WHERE THE MULTI-MODEL ENSEMBLE MEAN SOLUTIONS HAVE 5-DAY TEMPERATURES
AVERAGING NEAR OR MORE THAN 10 DEGREES F ABOVE NORMAL.
AS OF 11 AM AST ON AUGUST 14, TROPICAL STORM ERIN IS LOCATED CLOSE TO 900 MILES
EAST OF THE NORTHERN LEEWARD ISLANDS AND THE NATIONAL HURRICANE CENTER (NHC)
FORECASTS ERIN TO STRENGTHEN TO A HURRICANE WITHIN THE NEXT 12 HOURS. ALTHOUGH
ERIN IS EXPECTED TO TURN NORTHWEST DUE TO A WEAKNESS IN THE SUBTROPICAL RIDGE,
THE WEST-TO-EAST MODEL SPREAD ON ITS EXACT TRACK BECOMES LARGE BY EARLY NEXT
WEEK. PLEASE REFER TO THE NHC (WWW.NHC.NOAA.GOV) FOR THE LATEST FORECAST
DETAILS. AT THIS TIME, THE MODEL CONSENSUS IS FOR THE DEEP 500-HPA TROUGH OVER
THE CANADIAN MARITIMES TO EVENTUALLY STEER ERIN NORTHEAST AND AWAY FROM THE
EAST COAST LATER NEXT WEEK. ONE OR TWO COLD FRONTAL PASSAGES FAVOR NEAR TO
ABOVE-NORMAL PRECIPITATION ACROSS THE NORTHEAST AND MID-ATLANTIC, WHILE THE
TILT TOWARDS ABOVE NORMAL ACROSS THE SOUTHEAST AND GULF COAST STATES IS RELATED
TO A WEAKER-THAN-NORMAL SUBTROPICAL RIDGE FOSTERING DIURNAL CONVECTION.
PREVAILING SURFACE HIGH PRESSURE ELEVATES THE CHANCE OF BELOW-NORMAL
PRECIPITATION ACROSS FROM THE GREAT LAKES SOUTHWEST TO THE MIDDLE MISSISSIPPI
VALLEY. A 500-HPA RIDGE AXIS IS FORECAST TO BE CENTERED ACROSS THE FOUR CORNERS
WHICH IS A FAVORABLE LOCATION FOR AN ENHANCED MONSOON. INITIALLY, THE MID-LEVEL
RIDGE SHOULD BE STRONG ENOUGH TO LIMIT CONVECTION BUT AS 500-HPA HEIGHTS
DECREASE, CONVECTIVE RAINFALL IS EXPECTED TO INCREASE LATER IN THIS PERIOD.
THEREFORE, ABOVE-NORMAL PRECIPITATION IS FAVORED FROM THE SOUTHWEST NORTHWARD
TO THE GREAT BASIN AND CENTRAL ROCKIES. NORTHWEST FLOW ALOFT WITH EMBEDDED
SHORTWAVE TROUGHS ELEVATE ABOVE-NORMAL PRECIPITATION PROBABILITIES ACROSS THE
NORTH-CENTRAL CONUS. ALTHOUGH LATE AUGUST IS A DRIER TIME OF YEAR, BELOW-NORMAL
PRECIPITATION IS STILL THE MOST LIKELY OUTCOME FOR THE PACIFIC NORTHWEST AND
NORTHERN INTERMOUNTAIN WEST WITH BROAD 500-HPA RIDGING OVER WESTERN NORTH
AMERICA.
THE GEFS, ECENS, AND CMCE DEPICT A SOUTHWEST TO NORTHEAST ORIENTED 500-HPA
RIDGE FROM THE ALEUTIANS TO EASTERN MAINLAND ALASKA. THIS RIDGE FAVORS
ABOVE-NORMAL TEMPERATURES STATEWIDE WITH BELOW-NORMAL PRECIPITATION FAVORED FOR
SOUTHEASTERN ALASKA. FARTHER TO THE NORTHWEST, ENHANCED ONSHORE FLOW INCREASES
THE CHANCE FOR ABOVE-NORMAL PRECIPITATION ACROSS WESTERN AND NORTHERN MAINLAND
ALASKA.
BASED ON THE GEFS AND ECENS, ABOVE-NORMAL TEMPERATURES AND NEAR TO ABOVE-NORMAL
PRECIPITATION ARE FAVORED FOR HAWAII.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 35% 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD MODEL AGREEMENT AND CONSISTENCY ON THE LONGWAVE PATTERN.
8-14 DAY OUTLOOK FOR AUG 22 - 28 2025
MULTI-MODEL ENSEMBLE MEANS (GEFS, ECENS, AND CMCE) ARE IN GOOD AGREEMENT WITH
AN AMPLIFIED RIDGE OVER WESTERN NORTH AMERICA AND A DOWNSTREAM TROUGH CENTERED
NEAR THE EAST COAST. THE LARGEST NEGATIVE 500-HPA HEIGHT ANOMALIES, ASSOCIATED
WITH THIS TROUGH, ARE OVER SOUTHEASTERN CANADA. THE HIGHEST FORECAST CONFIDENCE
IN THE WEEK-2 TEMPERATURE OUTLOOK IS ACROSS THE WEST AND FROM THE SOUTHERN
GREAT PLAINS EASTWARD TO THE SOUTHEAST. THE PERSISTENT 500-HPA RIDGE IS LIKELY
TO MAINTAIN ABOVE-NORMAL TEMPERATURES ACROSS THE WEST THROUGHOUT WEEK-2. COLD
FRONTS ARE UNLIKELY TO PROGRESS MUCH FARTHER SOUTH THAN THE 40TH PARALLEL WHICH
FAVORS ABOVE-NORMAL TEMPERATURES FOR THE SOUTHERN TIER OF THE CONUS.
BELOW-NORMAL TEMPERATURES ARE FAVORED FOR THE MID-ATLANTIC AND NORTHEAST, AND
MORE ANOMALOUSLY COOL TEMPERATURES FOR LATE AUGUST COULD OCCUR IF ERIN MOVES
CLOSE ENOUGH TO THE EAST COAST AND RESULTS IN STRONGER COLD ADVECTION. MODEL
GUIDANCE INDICATES THAT THE GREAT LAKES AND UPPER MISSISSIPPI VALLEY START OFF
WITH ABOVE-NORMAL TEMPERATURES, BUT A COLD FRONT AROUND DAY 10 IS EXPECTED TO
CAUSE A TRANSITION TO BELOW-NORMAL TEMPERATURES. THE WEEK-2 OUTLOOK FAVORS
BELOW-NORMAL TEMPERATURES FOR THESE AREAS, BUT FORECAST CONFIDENCE IS LOW DUE
TO THE PREDICTED TEMPERATURE CHANGE.
THE 500-HPA LONGWAVE PATTERN OVER THE WEST, WITH THE RIDGE AXIS CENTERED ACROSS
THE FOUR CORNERS, FAVORS ABOVE-NORMAL PRECIPITATION FROM THE SOUTHWEST NORTH TO
THE GREAT BASIN AND CENTRAL ROCKIES. THE WET TILT ACROSS THE NORTHERN TO
CENTRAL GREAT PLAINS IS RELATED TO SHORTWAVE TROUGHS MOVING OVER THE WESTERN
RIDGE AND SOUTHEASTWARD. BASED ON THE SKILL-WEIGHTED GEFS AND ECENS REFORECAST
TOOLS AND UNCALIBRATED MODEL OUTPUT, BELOW-NORMAL PRECIPITATION PROBABILITIES
ARE SLIGHTLY ELEVATED FROM THE GREAT LAKES SOUTHWESTWARD TO THE MIDDLE
MISSISSIPPI VALLEY AND OZARKS REGION. BY THE BEGINNING OF WEEK-2 (AUGUST 22),
THE GEFS AND ECENS DEPICT TROPICAL CYCLONE ERIN MOVING AWAY FROM THE EAST
COAST. PRECIPITATION TOOLS HAVE WEAK SIGNALS THROUGHOUT THE EASTERN CONUS AND
NEAR NORMAL PRECIPITATION IS FORECAST WHICH IS CONSISTENT WITH ONE OR TWO
PROGRESSIVE FRONTAL PASSAGES.
POSITIVE 500-HPA HEIGHT ANOMALIES ALONG WITH SOUTHWESTERLY SURFACE FLOW OVER
WESTERN ALASKA FAVORS ABOVE-NORMAL TEMPERATURES THROUGHOUT ALASKA. SIMILAR TO
THE 6-10 DAY PERIOD, BELOW-NORMAL PRECIPITATION IS MOST LIKELY FOR SOUTHEASTERN
ALASKA WITH ENHANCED ONSHORE FLOW FROM THE BERING SEA LEADING TO AN INCREASED
CHANCE OF ABOVE-NORMAL PRECIPITATION ACROSS WESTERN AND NORTHERN MAINLAND
ALASKA.
BASED ON THE GEFS AND ECENS, ABOVE-NORMAL TEMPERATURES AND NEAR TO ABOVE-NORMAL
PRECIPITATION ARE FAVORED FOR HAWAII. POSITIVE SEA SURFACE TEMPERATURE
ANOMALIES ALSO SUPPORT ABOVE-NORMAL TEMPERATURES, ESPECIALLY ACROSS THE
NORTHWESTERN ISLANDS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z 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, DUE TO GOOD
MODEL AGREEMENT OFFSET BY WEAK SIGNALS IN THE PRECIPITATION GUIDANCE THROUGHOUT
THE LOWER 48 STATES.
FORECASTER: BRAD PUGH
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
AUGUST 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:
19960806 - 19810726 - 19620828 - 19880802 - 19980815
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:
19620827 - 19810728 - 19960805 - 19590827 - 20060726
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 20 - 24 2025
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 B NEVADA A A
W MONTANA A B E MONTANA A A WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A N OKLAHOMA A N
N TEXAS A A S TEXAS A A W TEXAS A N
MINNESOTA A N IOWA N N MISSOURI A B
ARKANSAS A N LOUISIANA A N WISCONSIN N N
ILLINOIS N B MISSISSIPPI A N MICHIGAN N B
INDIANA N B OHIO N N KENTUCKY A N
TENNESSEE A A ALABAMA A N NEW YORK B N
VERMONT B N NEW HAMP B N MAINE B N
MASS B A CONN B A RHODE IS B A
PENN N A NEW JERSEY B A W VIRGINIA N A
MARYLAND B A DELAWARE B A VIRGINIA B A
N CAROLINA N A S CAROLINA A A GEORGIA A A
FL PNHDL A N FL PENIN A N AK N SLOPE A A
AK ALEUTIAN A B AK WESTERN A A AK INT BSN A A
AK S INT A B AK SO COAST A B AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 22 - 28 2025
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 A NEVADA A A
W MONTANA A N E MONTANA N A WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA B N S DAKOTA N A
NEBRASKA A A KANSAS A N OKLAHOMA A N
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA B N IOWA B N MISSOURI A B
ARKANSAS A B LOUISIANA A N WISCONSIN B N
ILLINOIS B B MISSISSIPPI A N MICHIGAN B B
INDIANA B B OHIO B N KENTUCKY N N
TENNESSEE N N ALABAMA A N NEW YORK B N
VERMONT B N NEW HAMP B N MAINE B N
MASS B N CONN B N RHODE IS B N
PENN B N NEW JERSEY B N W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA N N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE A A
AK ALEUTIAN A N AK WESTERN A A AK INT BSN A A
AK S INT A N AK SO COAST A 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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