007  
FXUS06 KWBC 302007  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST TUE JANUARY 30 2018  
 
6-10 DAY OUTLOOK FOR FEB 05 - 09 2018  
 
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE EXPECTED  
500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. AN AMPLIFIED, BROADLY CYCLONIC  
FLOW PATTERN IS ANTICIPATED ACROSS THE NORTH-CENTRAL CONUS. A RIDGE IS  
PREDICTED OVER THE EAST PACIFIC APPROACHING THE NORTH AMERICAN WEST COAST,  
WHILE A TROUGH IS EXPECTED OVER NORTHERN HUDSON BAY. A STRONG CLOSED-OFF RIDGE  
IS FORECAST NORTHWEST OF ALASKA. TODAY'S MANUAL 500-HPA BLEND IS BASED  
PRIMARILY ON THE ENSEMBLE MEANS FROM THE CANADIAN, EUROPEAN, AND GEFS MODEL  
SUITES. THE RESULTANT MANUAL BLEND DEPICTS NEAR TO BELOW NORMAL HEIGHTS OVER  
THE NORTH-CENTRAL CONUS, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED  
OVER THE REMAINDER OF THE FORECAST DOMAIN.  
 
NEAR TO ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES OF NEAR TO ABOVE NORMAL  
TEMPERATURES FOR MUCH OF THE WESTERN CONUS, PARTS OF THE SOUTHERN HIGH PLAINS,  
THE SOUTHEAST U.S., WESTERN MAINLAND ALASKA AND THE ALEUTIANS. ARCTIC HIGH  
PRESSURE IS LIKELY TO SHIFT SOUTHEAST FROM WESTERN CANADA, STRONGLY FAVORING  
BELOW NORMAL TEMPERATURES FOR THE NORTHERN PLAINS, THE GREAT LAKES, THE UPPER  
AND MIDDLE MISSISSIPPI VALLEYS, THE OHIO VALLEY, THE NORTHEAST, AND PARTS OF  
THE TENNESSEE VALLEY AND THE MIDDLE ATLANTIC AREAS.  
 
THE BROAD TROUGH FORECAST OVER THE CONUS FAVORS ABOVE NORMAL PRECIPITATION FOR  
THE EAST COAST OF THE CONUS, PARTS OF THE NORTHERN AND CENTRAL ROCKIES, THE  
NORTHERN AND CENTRAL PLAINS, THE UPPER AND MIDDLE MISSISSIPPI VALLEY, AND THE  
UPPER GREAT LAKES. ANOMALOUS SOUTHEASTERLY FLOW TILTS THE ODDS TO ABOVE NORMAL  
PRECIPITATION FOR SOUTHERN MAINLAND ALASKA AND THE ALEUTIANS. ABOVE NORMAL  
HEIGHTS AND/OR ANOMALOUS NORTHWESTERLY 500-HPA FLOW FAVORS NEAR TO BELOW NORMAL  
PRECIPITATION FOR THE REMAINDER OF THE CONUS AND NORTHERN MAINLAND ALASKA.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 15% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 5% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 25% OF TODAY'S 0Z  
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF YESTERDAY'S 12Z EUROPEAN  
ENSEMBLE MEAN CENTERED ON DAY 7, 10% OF TODAY'S OPERATIONAL 0Z ECMWF CENTERED  
ON DAY 8, 20% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 5% OF  
YESTERDAY'S 12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 7  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO  
GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS AND AMONG THE SURFACE TOOLS.  
 
8-14 DAY OUTLOOK FOR FEB 07 - 13 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. 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. ARCTIC HIGH PRESSURE IS LIKELY TO  
BECOME CENTERED ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY BY THE  
BEGINNING OF WEEK-2.  
 
ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR NEAR TO ABOVE NORMAL  
TEMPERATURES FOR MUCH OF THE WESTERN CONUS AND PARTS OF THE SOUTHEAST. BELOW  
NORMAL HEIGHTS AND/OR COLD SURFACE HIGH PRESSURE TILT THE ODDS TO NEAR TO BELOW  
NORMAL TEMPERATURES FOR MUCH OF THE EASTERN AND CENTRAL CONUS. ABOVE NORMAL  
HEIGHTS FAVOR ABOVE NORMAL TEMPERATURE FOR ALL OF ALASKA.  
 
THE TROUGH OVER THE NORTH-CENTRAL U.S. ENHANCES PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION FOR PARTS OF THE NORTHERN PLAINS, ALABAMA, GEORGIA, CAROLINA AND  
NEW ENGLAND. ABOVE NORMAL HEIGHTS AND/OR ANOMALOUS NORTH/NORTHWESTERLY FLOW  
FAVORS BELOW NORMAL PRECIPITATION FOR THE WESTERN THIRD OF THE CONUS AND PARTS  
OF THE CENTRAL AND SOUTHERN PLAINS. ANOMALOUS SOUTHERLY FLOW TILTS THE ODDS TO  
ABOVE NORMAL PRECIPITATION FOR SOUTHERN MAINLAND ALASKA, THE ALASKA PANHANDLE  
AND THE ALEUTIANS, WHILE ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR NEAR TO  
BELOW NORMAL PRECIPITATION FOR PARTS OF NORTHERN MAINLAND ALASKA.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 20% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 5% OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 11, 30% OF TODAY'S  
0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 5% OF YESTERDAY'S 12Z EUROPEAN  
ENSEMBLE MEAN CENTERED ON DAY 10, 20% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN  
CENTERED ON DAY 11, AND 5% OF YESTERDAY'S 12Z CANADIAN ENSEMBLE MEAN CENTERED  
ON DAY 10  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO  
FAIR AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFF-SET BY MODERATE TO LARGE  
SPREAD AMONG ENSEMBLE MEMBERS OVER PARTS OF THE FORECAST DOMAIN.  
 
FORECASTER: LUKE 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  
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:  
19510122 - 19530126 - 19540126 - 19590114 - 19560113  
 
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:  
19510123 - 19530125 - 19590114 - 19540125 - 19560113  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 05 - 09 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 A E MONTANA N A WYOMING A A  
UTAH A B ARIZONA A B COLORADO A N  
NEW MEXICO A B N DAKOTA B A S DAKOTA B A  
NEBRASKA N A KANSAS N N OKLAHOMA N B  
N TEXAS N N S TEXAS N N W TEXAS A B  
MINNESOTA B A IOWA B A MISSOURI B N  
ARKANSAS B N LOUISIANA N N WISCONSIN B A  
ILLINOIS B A MISSISSIPPI N N MICHIGAN B A  
INDIANA B N OHIO B N KENTUCKY B N  
TENNESSEE B N ALABAMA N N NEW YORK B N  
VERMONT B A NEW HAMP B A MAINE B A  
MASS B A CONN B A RHODE IS B A  
PENN B N NEW JERSEY B A W VIRGINIA B N  
MARYLAND B A DELAWARE B A VIRGINIA B N  
N CAROLINA N A S CAROLINA N A GEORGIA N A  
FL PNHDL A A FL PENIN A A AK N SLOPE N B  
AK ALEUTIAN A A AK WESTERN A A AK INT BSN N N  
AK S INT N A AK SO COAST N A AK PNHDL N A  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 07 - 13 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 N N E MONTANA B A WYOMING N N  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA B A S DAKOTA B N  
NEBRASKA B N KANSAS B B OKLAHOMA B B  
N TEXAS B B S TEXAS B N W TEXAS A B  
MINNESOTA B N IOWA B N MISSOURI B N  
ARKANSAS B N LOUISIANA B N WISCONSIN B N  
ILLINOIS B N MISSISSIPPI B N MICHIGAN B N  
INDIANA B N OHIO B N KENTUCKY B N  
TENNESSEE B N ALABAMA N A NEW YORK B N  
VERMONT B A NEW HAMP B A MAINE B A  
MASS B A CONN B A RHODE IS B A  
PENN B N NEW JERSEY B N W VIRGINIA B N  
MARYLAND B N DELAWARE B N VIRGINIA B N  
N CAROLINA B A S CAROLINA N A GEORGIA N A  
FL PNHDL A N FL PENIN A N AK N SLOPE A B  
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 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.  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page