901
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 JUNE 18 2018
6-10 DAY OUTLOOK FOR JUN 24 - 28 2018
TODAY'S MODEL SOLUTIONS ARE IN FAIR AGREEMENT ON THE OVERALL 500-HPA FLOW
PATTERN OVER THE FORECAST DOMAIN. AT THE BEGINNING OF THE PERIOD, MODELS DEPICT
A TROUGH OVER THE EASTERN BERING SEA EXTENDING SOUTHEASTWARD OVER THE GULF OF
ALASKA. SPLIT-FLOW IS ANTICIPATED FARTHER TO THE EAST WITH RIDGES FORECAST OVER
CENTRAL CANADA AS WELL AS ALONG THE WEST COAST OF THE CONUS. SHORTWAVE TROUGHS
ARE FORECAST OVER THE WEST-CENTRAL AND EAST-CENTRAL CONUS WHILE A STRONGER,
LONGWAVE TROUGH IS ANTICIPATED OVER EASTERN CANADA. BY THE END OF THE PERIOD,
THE TROUGH OVER THE GULF OF ALASKA IS EXPECTED TO APPROACH THE NORTHWESTERN
CONUS RESULTING IN A LOWERING OF HEIGHTS ALONG THE WEST COAST. MEANWHILE THE
SHORTWAVE TROUGHS OVER THE WEST-CENTRAL AND EAST-CENTRAL CONUS FORECAST TO
PROGRESS EASTWARD WITH TIME TOWARD THE PLAINS AND NORTHEAST. THE MEAN, MANUAL,
500-HPA HEIGHT BLEND FOR THE FIVE DAY PERIOD, BASED PRIMARILY ON THE ENSEMBLE
MEAN SOLUTIONS FROM THE GEFS AND ECMWF, DEPICTS NEAR TO ABOVE NORMAL HEIGHTS
OVER THE CONUS AND NEAR TO BELOW NORMAL HEIGHTS ACROSS ALASKA.
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE CONUS UNDERNEATH NEAR TO
ABOVE NORMAL HEIGHTS. HOWEVER, ENHANCED PROBABILITIES OF NEAR NORMAL
TEMPERATURES ARE INDICATED FOR THE PACIFIC NORTHWEST AS A TROUGH APPROACHES THE
AREA BY THE END OF THE PERIOD. NEAR NORMAL TEMPERATURES ARE ALSO FAVORED FOR
PARTS OF THE CENTRAL AND SOUTHERN ROCKIES AND CENTRAL AND SOUTHERN HIGH PLAINS
DUE TO AN ANTICIPATED SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT. TROUGHING AND
NEAR TO BELOW NORMAL HEIGHTS LEAD TO ENHANCED PROBABILITIES OF BELOW NORMAL
TEMPERATURES FOR MUCH OF MAINLAND ALASKA AND THE ALASKA PANHANDLE. HOWEVER,
ABOVE NORMAL SSTS FAVOR ABOVE NORMAL TEMPERATURES FOR PARTS OF THE WESTERN
COAST OF MAINLAND ALASKA AND FOR PARTS OF THE ALEUTIANS.
TROUGHING OVER ALASKA LEADS TO ENHANCED PROBABILITIES OF NEAR TO ABOVE NORMAL
PRECIPITATION ACROSS THE STATE. BELOW NORMAL PRECIPITATION IS FAVORED FOR THE
NORTHWESTERN CONUS IN ASSOCIATION WITH ANTICIPATED SURFACE HIGH PRESSURE
UPSTREAM OVER THE EASTERN NORTH PACIFIC. BELOW NORMAL PRECIPITATION IS ALSO
FAVORED FOR PARTS OF THE SOUTHWEST DUE TO MEAN SUBTROPICAL RIDGING CENTERED
NEAR THE U.S./MEXICO BORDER. CONVERSELY, THERE ARE ENHANCED PROBABILITIES OF
ABOVE NORMAL PRECIPITATION FROM THE CENTRAL PLAINS EXTENDING TO THE
NORTHEASTERN CONUS AS SHORTWAVE TROUGHS PROGRESS TROUGH THESE REGIONS. RIDGING
OVER EAST-CENTRAL CANADA LEADS TO ENHANCED PROBABILITIES OF BELOW NORMAL
PRECIPITATION FOR PARTS OF THE WESTERN GREAT LAKES REGION AND UPPER MISSISSIPPI
VALLEY. ABOVE NORMAL PRECIPITATION IS ALSO FAVORED FOR PARTS OF THE
SOUTHEASTERN CONUS DUE TO THE POTENTIAL FOR MOIST FLOW AROUND SURFACE HIGH
PRESSURE CENTERED OVER THE ATLANTIC. BELOW NORMAL PRECIPITATION IS SLIGHTLY
FAVORED FARTHER TO THE WEST FOR PARTS OF THE WESTERN GULF COAST REGION,
CONSISTENT WITH DYNAMICAL MODEL GUIDANCE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 25% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 8, 10% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 20% OF TODAY'S
0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF TODAY'S OPERATIONAL 0Z
ECMWF CENTERED ON DAY 8, AND 15% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED
ON DAY 8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIR
MODEL AGREEMENT.
8-14 DAY OUTLOOK FOR JUN 26 - JUL 02, 2018
DURING THE WEEK-2 PERIOD, THE ENSEMBLE MEAN SOLUTIONS FROM THE GEFS, ECMWF, AND
CANADIAN ALL FORECAST TROUGHS OVER THE BERING SEA AND THE NORTHWESTERN CONUS.
FARTHER TO THE EAST, RIDGING AND ABOVE NORMAL HEIGHTS ARE ANTICIPATED OVER
EAST-CENTRAL CANADA EXTENDING TO PARTS OF THE GREAT LAKES AND NORTHEAST. A
RIDGE IS FORECAST OVER MUCH OF THE SOUTHWESTERN CONUS WHILE A WEAKNESS IN THE
SUBTROPICAL RIDGE IS PREDICTED OVER PARTS OF THE SOUTHEASTERN CONUS,
PARTICULARLY BY THE 0Z ECMWF ENSEMBLE MEAN. THE MANUAL, 500-HPA BLEND, WEIGHTED
MOST HEAVILY TOWARD THE 0Z ECMWF ENSEMBLE MEAN, FEATURES NEAR TO ABOVE NORMAL
HEIGHTS FOR THE CONUS AND NEAR TO BELOW NORMAL HEIGHTS FOR MUCH OF ALASKA.
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE CONUS, UNDER NEAR TO
ABOVE NORMAL 500-HPA HEIGHTS. HOWEVER, NEAR TO BELOW NORMAL TEMPERATURES ARE
FAVORED FOR THE NORTHWESTERN CONUS DUE TO A PREDICTED TROUGH. THE PREDICTED
TEMPERATURE PATTERN FOR ALASKA IS SIMILAR BETWEEN THE 6-10 AND 8-14 DAY
PERIODS.
PERSISTENT TROUGHING OVER THE EASTERN BERING SEA LEADS TO ENHANCED
PROBABILITIES OF NEAR TO ABOVE NORMAL PRECIPITATION ACROSS ALASKA. STRONG,
SURFACE HIGH PRESSURE OVER THE EASTERN NORTH PACIFIC AND ASSOCIATED NORTHERLY,
LOW-LEVEL FLOW FAVOR BELOW NORMAL PRECIPITATION ACROSS THE NORTHWESTERN CONUS.
THERE ARE ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION FARTHER TO THE
EAST FOR PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY CONSISTENT
WITH DYNAMICAL MODEL GUIDANCE AND WITH TELECONNECTIONS FROM A POSITIVE HEIGHT
ANOMALY CENTER ANTICIPATED OVER EASTERN CANADA. CONVERSELY, THE RIDGE FORECAST
OVER EASTERN CANADA FAVORS BELOW NORMAL PRECIPITATION FOR PARTS OF THE
NORTHEASTERN CONUS. SUBTROPICAL RIDGING LEADS TO FAVORED BELOW NORMAL
PRECIPITATION FOR THE SOUTHERN PLAINS. A FORECAST WEAKNESS IN THE SUBTROPICAL
RIDGE FAVORS ABOVE NORMAL PRECIPITATION ACROSS THE SOUTHEASTERN CONUS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 15% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 11, 5% OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 11, 45% OF TODAY'S
0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 15% OF TODAY'S 0Z CANADIAN
ENSEMBLE MEAN CENTERED ON DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
FAIR MODEL AGREEMENT.
FORECASTER: SCOTT H
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 1981-2010 BASE PERIOD MEANS FOR
TEMPERATURE...PRECIPITATION...AND 500-HPA HEIGHTS AS REFERENCE IN THE CLIMATE
OUTLOOKS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON
JUNE 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:
19890622 - 19950628 - 20060610 - 19750702 - 19510626
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:
19890622 - 19950628 - 19750701 - 20060609 - 19700614
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUN 24 - 28 2018
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N B OREGON A B NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A N
UTAH A B ARIZONA A B COLORADO N A
NEW MEXICO A B N DAKOTA A N S DAKOTA A N
NEBRASKA A A KANSAS N A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA A B IOWA A N MISSOURI A A
ARKANSAS A A LOUISIANA A B WISCONSIN A B
ILLINOIS A A MISSISSIPPI A N MICHIGAN A 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 N
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 N A
AK ALEUTIAN N A AK WESTERN N N AK INT BSN B N
AK S INT B A AK SO COAST B A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUN 26 - JUL 02, 2018
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N B OREGON N B NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A N
W MONTANA N B E MONTANA A N WYOMING A B
UTAH A B ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A A S DAKOTA A N
NEBRASKA A N KANSAS A B OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A N LOUISIANA A N WISCONSIN A A
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 N
VERMONT A B NEW HAMP A B MAINE A B
MASS A B CONN A N RHODE IS A N
PENN A N NEW JERSEY A N W VIRGINIA A A
MARYLAND A N DELAWARE A N 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 N N
AK ALEUTIAN A A AK WESTERN N A AK INT BSN N N
AK S INT B A AK SO COAST B A AK PNHDL B 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.
$$