078  
FXUS06 KWBC 012002  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST THU FEBRUARY 01 2018  
 
6-10 DAY OUTLOOK FOR FEB 07 - 11 2018  
 
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE EXPECTED  
500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. A DEEP CLOSED-OFF TROUGH IS  
ANTICIPATED NORTH OF HUDSON BAY, EXTENDING SOUTHWARD, LEADING TO AN AMPLIFIED,  
BROADLY CYCLONIC FLOW PATTERN ACROSS MOST OF THE CONUS. A RIDGE IS PREDICTED  
OVER THE EAST PACIFIC APPROACHING THE NORTH AMERICAN WEST COAST AND EXTENDING  
NORTH/NORTHWESTWARD TO ALASKA. THERE IS SOME INDICATION THAT SOME SHORTWAVE  
ENERGY WILL UNDERCUT THE WESTERN RIDGE AS A WEAK SOUTHERN JET STREAM GETS  
ESTABLISHED. THE ENSEMBLE SPAGHETTI CHARTS INDICATE LOW TO MODERATE SPREAD OVER  
THE EASTERN CONUS, AND MODERATE TO LARGE SPREAD OVER THE WESTERN CONUS AND  
EASTERN PACIFIC. THE AO INDEX WHICH RECENTLY HAS BEEN NEAR ZERO IS EXPECTED TO  
REMAIN NEAR ZERO AT DAY 7, BE NEGATIVE AT DAY 10, AND REMAIN NEGATIVE AT DAY  
14. THE PNA INDEX WHICH RECENTLY HAS BEEN WEAKLY NEGATIVE IS FORECAST TO BECOME  
WEAKLY POSITIVE AT DAY 7, AND REMAIN POSITIVE THROUGH DAY 14. TODAY'S MANUAL  
500-HPA BLEND CHART DEPICTS NEAR TO BELOW NORMAL HEIGHTS OVER PARTS OF THE  
GREAT LAKES, UPPER MISSISSIPPI VALLEY, NORTHERN PLAINS, AND THE ALEUTIANS,  
WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED OVER THE REMAINDER OF THE  
FORECAST DOMAIN.  
 
NEAR TO BELOW NORMAL HEIGHTS AND/OR SURFACE ARCTIC HIGH PRESSURE ENHANCE  
PROBABILITIES OF NEAR TO BELOW NORMAL TEMPERATURES FOR MUCH OF THE CENTRAL AND  
EAST-CENTRAL CONUS. ANOMALOUS SOUTHEASTERLY FLOW TILTS THE ODDS TO ABOVE NORMAL  
TEMPERATURES FOR THE ALEUTIANS AND MUCH OF MAINLAND ALASKA. NEAR TO ABOVE  
NORMAL HEIGHTS FAVOR NEAR TO ABOVE NORMAL TEMPERATURES FOR THE REMAINDER OF THE  
FORECAST DOMAIN.  
 
THE BROAD TROUGH FORECAST OVER THE CONUS ENHANCES PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION FOR MUCH OF THE EASTERN QUARTER OF THE CONUS. UPSLOPE FLOW TILTS  
THE ODDS TO ABOVE NORMAL PRECIPITATION FOR A SMALL PORTION OF THE NORTHERN HIGH  
PLAINS. ANOMALOUS SOUTHEASTERLY FLOW FAVORS ABOVE NORMAL PRECIPITATION FOR THE  
ENTIRE SOUTH COAST OF ALASKA AND PARTS OF SOUTHWESTERN AND CENTRAL MAINLAND  
ALASKA. ANOMALOUS NORTHEASTERLY FLOW ENHANCES PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION FOR THE ALASKA PANHANDLE. ABOVE NORMAL HEIGHTS AND/OR ANOMALOUS  
NORTHERLY 500-HPA FLOW FAVORS NEAR TO BELOW NORMAL PRECIPITATION FOR THE  
REMAINDER OF THE CONUS.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 10% OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 20% OF TODAY'S  
0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF YESTERDAY'S 12Z EUROPEAN  
ENSEMBLE MEAN CENTERED ON DAY 7, AND 10% OF TODAY'S OPERATIONAL 0Z ECMWF  
CENTERED ON DAY 8  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO  
GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS AND FAIR AGREEMENT AMONG THE  
SURFACE TOOLS.  
 
8-14 DAY OUTLOOK FOR FEB 09 - 15 2018  
 
THE MEAN 500-HPA PATTERN EXPECTED FOR THE WEEK-2 PERIOD IS SIMILAR TO THAT  
DEPICTED FOR THE 6 TO 10 DAY TIME FRAME, ALTHOUGH A SLOW PROGRESSION OF THE  
MAIN CIRCULATION FEATURES IS INDICATED. THE ENSEMBLE SPAGHETTI CHARTS INDICATE  
MODERATE SPREAD OVER THE EASTERN CONUS, AND LARGE SPREAD OVER THE WESTERN CONUS  
AND EASTERN PACIFIC. NEAR TO ABOVE NORMAL HEIGHTS ARE FORECAST ACROSS MOST OF  
THE CONUS, SOUTHEASTERN MAINLAND ALASKA,AND THE ALASKA PANHANDLE, WHILE NEAR TO  
BELOW NORMAL HEIGHTS ARE ANTICIPATED OVER THE ALEUTIANS AND WESTERN AND  
NORTHERN MAINLAND ALASKA.  
 
ARCTIC SURFACE HIGH PRESSURE TILTS THE ODDS TO NEAR TO BELOW NORMAL  
TEMPERATURES FOR PARTS OF THE EASTERN CONUS. ABOVE NORMAL HEIGHTS FAVOR ABOVE  
NORMAL TEMPERATURES FOR MUCH OF THE WESTERN HALF OF THE CONUS, THE ALASKA  
PANHANDLE, AND PARTS OF SOUTHERN AND CENTRAL MAINLAND ALASKA. ANOMALOUS  
SOUTHEASTERLY FLOW ENHANCES PROBABILITIES OF ABOVE NORMAL TEMPERATURES FOR THE  
ALEUTIANS.  
 
ABOVE NORMAL HEIGHTS, ANOMALOUS NORTH/NORTHWESTERLY FLOW, AND SPRAWLING SURFACE  
HIGH PRESSURE FAVOR NEAR TO BELOW NORMAL PRECIPITATION FOR THE CONUS. ANOMALOUS  
SOUTH/SOUTHEASTERLY FLOW TILTS THE ODDS TO ABOVE NORMAL PRECIPITATION FOR PARTS  
OF THE ALEUTIANS, SOUTHWESTERN MAINLAND ALASKA, AND THE ALASKA PANHANDLE.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 30% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 25% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 15% OF  
TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 20% OF YESTERDAY'S  
12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO  
FAIR AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFF-SET BY MODERATE TO LARGE  
SPREAD AMONG ENSEMBLE MEMBERS OVER MUCH OF THE FORECAST DOMAIN.  
 
FORECASTER: RANDY S  
 
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  
FEBRUARY 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:  
19820211 - 19530126 - 19590117 - 19510123 - 19890131  
 
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:  
19510124 - 19590116 - 19820210 - 19530126 - 19540125  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 07 - 11 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A B 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 N B  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA B A S DAKOTA B N  
NEBRASKA B B KANSAS B B OKLAHOMA B B  
N TEXAS B B S TEXAS B N W TEXAS N B  
MINNESOTA B N IOWA B B MISSOURI B B  
ARKANSAS B N LOUISIANA B A WISCONSIN B N  
ILLINOIS B N MISSISSIPPI B A MICHIGAN B N  
INDIANA B N OHIO B A KENTUCKY B A  
TENNESSEE B A ALABAMA B A NEW YORK B A  
VERMONT B A NEW HAMP N A MAINE N A  
MASS N A CONN N A RHODE IS N A  
PENN B A NEW JERSEY N A W VIRGINIA B A  
MARYLAND N A DELAWARE N A VIRGINIA B A  
N CAROLINA N A S CAROLINA N A GEORGIA N A  
FL PNHDL N A FL PENIN A A AK N SLOPE N N  
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A  
AK S INT A A AK SO COAST A A AK PNHDL A A  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 09 - 15 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A B OREGON A B NRN CALIF A B  
SRN CALIF A B IDAHO A B NEVADA A B  
W MONTANA A B E MONTANA A B WYOMING A B  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA A B S DAKOTA A B  
NEBRASKA A B KANSAS A B OKLAHOMA A B  
N TEXAS N B S TEXAS B N W TEXAS A B  
MINNESOTA A N IOWA A B MISSOURI N B  
ARKANSAS N B LOUISIANA B B WISCONSIN B B  
ILLINOIS N B MISSISSIPPI N B MICHIGAN B B  
INDIANA B B OHIO B B KENTUCKY N B  
TENNESSEE N B ALABAMA N B NEW YORK B B  
VERMONT B B NEW HAMP B B MAINE B B  
MASS B B CONN B N RHODE IS B N  
PENN B B NEW JERSEY B N W VIRGINIA B B  
MARYLAND B N DELAWARE B N VIRGINIA B N  
N CAROLINA N N S CAROLINA N B GEORGIA N B  
FL PNHDL N B FL PENIN N B AK N SLOPE N N  
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A N  
AK S INT A A AK SO COAST A A AK PNHDL A 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.  
 

 
 
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