657
FXUS06 KWBC 061909
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU JULY 06 2023
6-10 DAY OUTLOOK FOR JUL 12 - 16 2023
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT REGARDING AN AMPLIFIED 500-HPA
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 PARTS OF 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
CULMINATING AT 596-597 DM ACROSS PARTS OF ARIZONA AND NEW MEXICO IN THE 0Z
ECMWF, GFS, AND CANADIAN ENSEMBLES DURING DAYS 8-10. 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 THE
NORTHERN AND CENTRAL GREAT PLAINS, UPPER AND MIDDLE MISSISSIPPI VALLEY, THE
GREAT LAKES REGION, AND OHIO VALLEY 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 0Z ECMWF AND
CANADIAN ENSEMBLE MEANS FAVOR WIDESPREAD ANOMALOUS WARMTH OVER THE PACIFIC
NORTHWEST IN COMPARISON TO THE SLIGHTLY COOLER 0Z GEFS SOLUTION, ESPECIALLY
DURING THE FIRST FEW DAYS OF THE PERIOD. ACROSS THE CONUS, THE HIGHEST
PROBABILITIES OF ABOVE-NORMAL TEMPERATURES (>80 PERCENT) ARE DEPICTED ACROSS
PORTIONS OF SOUTHERN NEW MEXICO, WITH PROBABILITIES AT OR ABOVE 70% INDICATED
FROM EASTERN ARIZONA EAST-SOUTHEASTWARD ACROSS MOST OF TEXAS, SOUTHWESTERN
LOUISIANA, AND ALSO OVER 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 NEAR-NORMAL TEMPERATURES 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%) ARE FORECAST ACROSS PARTS OF NEW ENGLAND AND EASTERN NEW YORK STATE,
CONSISTENT WITH THE ECMWF REFORECAST TOOL. CONVERSELY, PROBABILITIES OF
BELOW-NORMAL PRECIPITATION ARE INCREASED ACROSS MUCH OF THE WESTERN CONUS,
EXTENDING INTO THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY 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 PARTS OF MONTANA, SUPPORTED BY THE GEFS AND ECMWF REFORECAST TOOLS.
INCREASED CHANCES FOR BELOW-NORMAL PRECIPITATION ARE FORECAST ACROSS FAR
SOUTHERN ALASKA DUE TO RIDGING FORECAST OVER THE ALEUTIANS, WITH INCREASED
ONSHORE FLOW LEADING TO SLIGHTLY ENHANCED ABOVE-NORMAL PRECIPITATION
PROBABILITIES ACROSS MUCH OF THE NORTHERN HALF OF THE STATE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 33% 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 THE FORECAST PERIOD.
8-14 DAY OUTLOOK FOR JUL 14 - 20 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 ALEUTIAN ARCHIPELAGO. 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. FOR THE PERIOD AS A WHOLE, THE 0Z ECMWF ENSEMBLE MEAN PREDICTS
ABOVE-NORMAL HEIGHTS ACROSS NEW ENGLAND, THOUGH THE 0Z GFS AND CANADIAN
ENSEMBLE MEANS ANTICIPATE NEAR-NORMAL HEIGHTS. 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 MIDWEST AND GREAT
LAKES REGION. 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 OVER CALIFORNIA, PORTIONS OF THE GREAT BASIN, AND
INTO THE PACIFIC NORTHWEST. FOR THE LATTER REGION, THIS IS TRUE OF THE 0Z ECMWF
AND CANADIAN ENSEMBLE MEANS DURING THE FIRST HALF OF WEEK-2.
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 ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI AND OHIO
VALLEYS. PROBABILITIES OF ABOVE-NORMAL TEMPERATURES REMAIN ELEVATED ACROSS MUCH
OF NEW ENGLAND AND PARTS OF NORTHEASTERN NEW YORK STATE 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 OF ABOVE-NORMAL
TEMPERATURES (>70 PERCENT) ARE HIGHLIGHTED IN THE VICINITY OF THE RIO GRANDE
VALLEY. INCREASING CHANCES OF ABOVE-NORMAL TEMPERATURES COMBINED WITH THE
APPROACH OF CLIMATOLOGICAL PEAK HEATING COULD LEAD TO MORE WIDESPREAD EXCESSIVE
HEAT CONCERNS.
AS DISCUSSED IN THE 6-10 DAY OUTLOOK, TROUGHING IS FORECAST TO LEAD TO ONE OR
MORE FRONTAL SYSTEMS MOVING ACROSS THE EASTERN CONUS INTO THE WEEK-2 PERIOD AS
WELL. AS A RESULT, ABOVE-NORMAL PRECIPITATION PROBABILITIES ARE INCREASED OVER
MUCH OF THE EASTERN CONUS, WITH THE HIGHEST PROBABILITIES (>40 PERCENT)
CENTERED ON THE LOWER OHIO AND TENNESSEE VALLEYS. ENHANCED PROBABILITIES FOR
BELOW-NORMAL PRECIPITATION ARE FAVORED FOR MUCH OF THE WEST, SOUTHERN PLAINS,
AND PARTS OF THE LOWER MISSISSIPPI VALLEY, DUE TO A PREDICTED INCREASE IN
SUBTROPICAL RIDGING OVER THE REGION, AND DELAYED MONSOON-RELATED PRECIPITATION
ACROSS PARTS OF THE SOUTHWEST. HOWEVER, THERE ARE SOME SIGNS OF INCREASING
MOISTURE OVER PARTS OF THE DESERT SOUTHWEST TIED TO POTENTIAL EAST PACIFIC
TROPICAL CYCLONE ACTIVITY, THOUGH FOR THE TIME BEING THE MAIN WEATHER CONCERN
IS THE EXTENDED PERIOD OF EXCESSIVE HEAT. NEAR- TO BELOW-NORMAL PRECIPITATION
IS FAVORED FOR SOUTHERN ALASKA, DUE TO THE NEARBY 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 RAW PRECIPITATION AMOUNTS FORECAST BY THE VARIOUS ENSEMBLE MEANS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 33% 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: 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
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:
19520711 - 19890621 - 19950629 - 19780719 - 19780707
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 - 19890622 - 19520715 - 19580708 - 19780707
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 12 - 16 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A B NRN CALIF A N
SRN CALIF A B IDAHO A B NEVADA A B
W MONTANA A N E MONTANA B A WYOMING N 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 N A OKLAHOMA A N
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA B N IOWA B A MISSOURI B A
ARKANSAS A N LOUISIANA A B WISCONSIN B N
ILLINOIS B A MISSISSIPPI A N MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY B A
TENNESSEE N A ALABAMA A A NEW YORK N 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 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 B AK WESTERN A N AK INT BSN A N
AK S INT A N AK SO COAST A B AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 14 - 20 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON A B NRN CALIF A N
SRN CALIF A N 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 N N OKLAHOMA A N
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA N N IOWA N N MISSOURI N A
ARKANSAS A A LOUISIANA A B WISCONSIN N N
ILLINOIS N A MISSISSIPPI A N MICHIGAN N N
INDIANA N A OHIO N A KENTUCKY N A
TENNESSEE N 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 N A
PENN N A NEW JERSEY N A W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA A N S CAROLINA A A 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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