723
FXUS06 KWBC 051902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED JULY 05 2023
6-10 DAY OUTLOOK FOR JUL 11 - 15 2023
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT REGARDING AN AMPLIFIED PATTERN
ACROSS THE MID- TO HIGH-LATITUDES OF NORTH AMERICA DURING THE 6-10 DAY PERIOD.
ANOMALOUS MID-LEVEL RIDGES ARE FORECAST ACROSS THE ALEUTIANS, NORTHWESTERN
CANADA, AND THE NORTHWEST ATLANTIC, WITH ANOMALOUS TROUGHING PREDICTED OVER
EAST-CENTRAL NORTH AMERICA. THIS TRANSLATES INTO ABOVE-NORMAL 500-HPA HEIGHTS
ACROSS MUCH OF ALASKA AND WESTERN CANADA, AND OVER THE NORTHEASTERN CONUS. THE
TROUGHING CENTERED ACROSS ONTARIO FAVORS NEAR- TO BELOW-NORMAL HEIGHTS ACROSS
THE NORTHERN PLAINS, UPPER MISSISSIPPI VALLEY, AND GREAT LAKES, AND EXTENDING
SOUTHWARD THROUGH THE OHIO AND TENNESSEE VALLEYS, AND MID-ATLANTIC. THIS
TROUGH-RIDGE SET-UP OVER NORTHEASTERN NORTH AMERICA IS CONSISTENT WITH A
NEGATIVE PHASE OF THE NORTH ATLANTIC OSCILLATION WHICH IS FORECAST TO CONTINUE
THROUGH MID-JULY. SUBTROPICAL RIDGING IS PREDICTED TO BUILD ACROSS THE SOUTHERN
CONUS THROUGHOUT THE PERIOD, WITH 500-HPA HEIGHTS EXCEEDING 597-DM ACROSS PARTS
OF ARIZONA AND NEW MEXICO IN THE 0Z ECMWF, GEFS, AND CANADIAN ENSEMBLES ON
DAY-10. ABOVE-NORMAL MID-LEVEL HEIGHTS ARE FORECAST FOR THE PERIOD AS A WHOLE
FROM CALIFORNIA EASTWARD THROUGH THE SOUTHERN HIGH PLAINS, WITH CLOSER TO
NORMAL HEIGHTS OVER THE NORTHWESTERN CONUS AND SOUTHEAST.
INCREASED PROBABILITIES OF BELOW-NORMAL TEMPERATURES ARE INDICATED ACROSS MUCH
OF THE MIDWEST TIED TO TROUGHING AND NEGATIVE MID-LEVEL HEIGHT ANOMALIES
FORECAST OVER THE REGION. ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE INCREASED
ACROSS PORTIONS OF THE NORTHEAST AHEAD OF THIS TROUGHING AND UNDERNEATH MORE
SOUTHERLY MID-LEVEL FLOW. CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE ELEVATED
OVER MUCH OF THE WESTERN AND SOUTHERN CONUS DUE TO THE PREDICTED INCREASE IN
SUBTROPICAL RIDGING. THE HIGHEST PROBABILITIES (>80 PERCENT) ARE DEPICTED
ACROSS PORTIONS OF SOUTHERN NEW MEXICO AND TEXAS, AND ALSO OVER SOUTH FLORIDA,
SUPPORTED BY THE GEFS AND ECMWF REFORECAST TOOLS. MID-LEVEL RIDGING GENERALLY
FAVORS INCREASED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES OVER MUCH OF
ALASKA, ALTHOUGH INCREASED ONSHORE FLOW AND INCREASED PRECIPITATION CHANCES
FAVOR A SLIGHT TILT TOWARD INCREASED BELOW-NORMAL TEMPERATURE PROBABILITIES
ALONG THE WESTERN MAINLAND COAST.
TROUGHING OVER THE EAST-CENTRAL CONUS IS LIKELY TO RESULT IN A SERIES OF
FRONTAL SYSTEMS MOVING ACROSS THE EASTERN HALF OF THE CONUS, AND SUBSEQUENT
HIGHER PROBABILITIES OF ABOVE-NORMAL PRECIPITATION. THE HIGHEST PROBABILITIES
(>50 PERCENT) ARE FORECAST ACROSS NEW ENGLAND, CONSISTENT WITH THE ECMWF
REFORECAST TOOL AND ALSO SUPPORTED BY ANALOGS BASED ON THE MANUAL 500-HPA
HEIGHT BLEND. CONVERSELY, PROBABILITIES OF BELOW-NORMAL PRECIPITATION ARE
INCREASED ACROSS MUCH OF THE WESTERN CONUS, EXTENDING INTO THE SOUTHERN PLAINS
DUE TO A TREND TOWARD MORE SUBTROPICAL RIDGING COMBINED WITH A LATE START TO
THE MONSOON SEASON. TROPICAL CYCLONE ACTIVITY IS FORECAST TO INCREASE ACROSS
THE EAST PACIFIC DURING THE NEXT WEEK, WHICH MAY BEGIN TO LEAD TO MORE MOISTURE
ADVECTION OVER PARTS OF THE SOUTHWEST AND FOUR CORNERS LATER IN THE PERIOD AND
INTO WEEK-2. ENHANCED PACIFIC FLOW FAVORS ELEVATED PROBABILITIES OF
ABOVE-NORMAL PRECIPITATION ACROSS NORTHERN PORTIONS OF WASHINGTON AND IDAHO,
AND MOST OF MONTANA, SUPPORTED BY THE GEFFS AND ECMWF REFORECAST TOOLS.
INCREASED CHANCES FOR BELOW-NORMAL PRECIPITATION ARE FORECAST ACROSS SOUTHERN
ALASKA DUE TO RIDGING FORECAST OVER THE ALEUTIANS, WITH INCREASED ONSHORE FLOW
LEADING TO SLIGHTLY ENHANCED ABOVE-NORMAL PRECIPITATION PROBABILITIES ACROSS
THE NORTHERN HALF OF THE STATE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, 5% OF TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND
20% 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
PERSISTENT SYNOPTIC PATTERN AND GOOD AGREEMENT AMONG FORECAST MODELS, OFFSET BY
WEAKENING OF HIGH AMPLITUDE PATTERN LATE IN FORECAST PERIOD.
8-14 DAY OUTLOOK FOR JUL 13 - 19 2023
THE 500-HPA HEIGHT PATTERN DURING WEEK-2 IS PREDICTED TO BE SIMILAR TO THE 6-10
DAY PERIOD, WITH SOME DECREASE IN AMPLIFICATION PREDICTED OVER NORTHEASTERN
NORTH AMERICA. RIDGING OVER THE BERING SEA AND WESTERN CANADA FAVORS
ABOVE-NORMAL MID-LEVEL HEIGHTS ACROSS ALASKA, WITH THE HIGHEST POSITIVE
ANOMALIES OVER THE ALEUTIANS. RIDGING ALSO REMAINS FORECAST ACROSS THE
NORTHWESTERN ATLANTIC, ALTHOUGH THE MAGNITUDE IS FORECAST TO WEAKEN LATER IN
THE PERIOD AS THE NORTH ATLANTIC OSCILLATION IS PREDICTED TO TREND LESS
NEGATIVE. AS A RESULT, ABOVE-NORMAL HEIGHTS ARE FORECAST ACROSS NEW ENGLAND FOR
THE PERIOD AS A WHOLE. TROUGHING INITIALLY FORECAST OVER THE EAST-CENTRAL CONUS
IS ALSO PREDICTED TO WEAKEN, WITH NEAR- TO SLIGHTLY BELOW-NORMAL HEIGHTS
FAVORED ACROSS PORTIONS OF THE UPPER MIDWEST. THE DECREASE IN AMPLIFICATION
FAVORS NEAR-NORMAL HEIGHTS ACROSS MUCH OF THE SOUTHEASTERN QUADRANT OF THE
CONUS. SUBTROPICAL RIDGING IS FORECAST TO CONTINUE TO EXPAND ACROSS THE
SOUTHWEST AND FOUR CORNERS WITH ABOVE-NORMAL MID-LEVEL HEIGHTS EXTENDING INTO
PARTS OF THE PACIFIC NORTHWEST AND GREAT BASIN, IN ADDITION TO CALIFORNIA, THE
DESERT SOUTHWEST, FOUR CORNERS, AND SOUTHERN HIGH PLAINS. THERE ARE SOME
INDICATIONS IN THE GUIDANCE THAT THIS RIDGE MAY BECOME A BROADER FEATURE BY THE
END OF WEEK-2 CONTRIBUTING TO RISING HEIGHTS ACROSS MUCH OF THE SOUTHERN HALF
OF THE CONUS.
THE WEAKENING OF THE NORTH ATLANTIC OSCILLATION FORECAST EARLY IN WEEK-2, ALONG
WITH THE DECREASING AMPLIFICATION OVER THE NORTHEASTERN CONUS SUPPORTS A
MODERATING TREND IN TEMPERATURES, WITH ENHANCED PROBABILITIES OF BELOW-NORMAL
TEMPERATURES ONLY REMAINING FAVORED ACROSS PORTIONS OF THE NORTHERN PLAINS AND
UPPER MISSISSIPPI VALLEY, WITH NEAR-NORMAL TEMPERATURES MORE LIKELY ACROSS MOST
OF THE GREAT LAKES, OHIO VALLEY, AND INTERIOR NORTHEAST. PROBABILITIES OF
ABOVE-NORMAL TEMPERATURES REMAIN ELEVATED ACROSS NEW ENGLAND DUE TO INCREASED
SOUTHERLY MID-LEVEL FLOW. CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE INCREASED
ACROSS MUCH OF THE WESTERN CONUS, ALONG WITH THE SOUTHERN HALF OF THE CONUS. AS
WITH THE 6-10 DAY OUTLOOK, THE HIGHEST PROBABILITIES (>80 PERCENT) ARE
HIGHLIGHTED ACROSS PORTIONS OF ARIZONA, NEW MEXICO, SOUTHWESTERN TEXAS, AND
SOUTH FLORIDA. INCREASING CHANCES OF ABOVE-NORMAL TEMPERATURES COMBINED WITH
THE APPROACH OF CLIMATOLOGICAL PEAK HEATING COULD LEAD TO MORE WIDESPREAD
EXCESSIVE HEAT CONCERNS BY MID- TO LATE-JULY.
AS DISCUSSED IN THE 6-10 DAY OUTLOOK, TROUGHING IS FORECAST TO LEAD TO ONE OR
MORE FRONTAL SYSTEMS MOVING ACROSS THE EASTERN CONUS EARLY IN THE WEEK-2
PERIOD. AS A RESULT, ABOVE-NORMAL PRECIPITATION PROBABILITIES ARE INCREASED
OVER MUCH OF THE EASTERN CONUS, WITH THE HIGHEST PROBABILITIES (>40 PERCENT)
STRETCHING FROM THE OHIO AND TENNESSEE VALLEYS TO THE NORTHEAST. ENHANCED
PROBABILITIES FOR BELOW-NORMAL PRECIPITATION ARE FAVORED FOR MUCH OF THE WEST
AND SOUTHERN PLAINS DUE TO A LATE START TO THE MONSOON AND PREDICTED INCREASE
IN SUBTROPICAL RIDGING OVER THE REGION, ALTHOUGH THERE ARE SOME SIGNS OF
INCREASING MOISTURE OVER THE REGION TIED TO POTENTIAL EAST PACIFIC TROPICAL
CYCLONE ACTIVITY. ENHANCED CHANCES FOR ABOVE-NORMAL PRECIPITATION ARE FORECAST
OVER NORTHERN WASHINGTON, NORTHERN IDAHO, AND EXTREME NORTHWESTERN MONTANA TIED
TO INCREASING PACIFIC FLOW AND SUPPORTED BY THE GEFS AND ECMWF REFORECAST
TOOLS. NEAR- TO BELOW-NORMAL PRECIPITATION IS FAVORED FOR PARTS OF SOUTHERN
ALASKA, DUE TO THE RIDGE CENTERED ACROSS THE ALEUTIANS. ABOVE-NORMAL
PRECIPITATION PROBABILITIES ARE INCREASED ACROSS MOST OF NORTHERN AND CENTRAL
MAINLAND ALASKA, DUE TO INCREASED ONSHORE FLOW AND SUPPORTED BY MOST DYNAMICAL
MODEL PRECIPITATION TOOLS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 40% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 20% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG MODEL ENSEMBLES ON THE PERSISTENT SYNOPTIC PATTERN, OFFSET
BY DECREASING AMPLIFICATION.
FORECASTER: THOMAS COLLOW
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
JULY 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:
19520709 - 19890621 - 19580707 - 19950629 - 19520714
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:
19520710 - 19890621 - 19580708 - 19780707 - 19520715
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 11 - 15 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A B NRN CALIF A B
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A A E MONTANA N A WYOMING A B
UTAH A B ARIZONA A B COLORADO A B
NEW MEXICO A B N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS A A OKLAHOMA A N
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA B A IOWA B A MISSOURI N A
ARKANSAS A N LOUISIANA A B WISCONSIN B A
ILLINOIS B A MISSISSIPPI A N MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY N A
TENNESSEE N 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 N A NEW JERSEY N A W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA N N
N CAROLINA A N S CAROLINA A N GEORGIA A A
FL PNHDL A N FL PENIN A N AK N SLOPE A A
AK ALEUTIAN N N AK WESTERN N A AK INT BSN A N
AK S INT A B AK SO COAST A B AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 13 - 19 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON A B NRN CALIF A B
SRN CALIF A B IDAHO A B NEVADA A B
W MONTANA A B E MONTANA N N WYOMING A B
UTAH A B ARIZONA A B COLORADO A B
NEW MEXICO A B N DAKOTA N N S DAKOTA N N
NEBRASKA N N KANSAS A N OKLAHOMA A N
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA B N IOWA N A MISSOURI A A
ARKANSAS A A LOUISIANA A B WISCONSIN N N
ILLINOIS A A MISSISSIPPI A N MICHIGAN N A
INDIANA N A OHIO N A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK N A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN N A RHODE IS A A
PENN N A NEW JERSEY N A W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA A A
N CAROLINA A N S CAROLINA A N GEORGIA A A
FL PNHDL A N FL PENIN A N AK N SLOPE A A
AK ALEUTIAN N N AK WESTERN N 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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