971  
FXUS06 KWBC 292048  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST MON JANUARY 29 2018  
 
6-10 DAY OUTLOOK FOR FEB 04 - 08 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. RIDGES ARE  
PREDICTED OVER THE EAST PACIFIC APPROACHING THE NORTH AMERICAN WEST COAST, AND  
THE CARIBBEAN, WHILE A TROUGH IS EXPECTED OVER NORTHERN HUDSON BAY. A STRONG  
CLOSED-OFF RIDGE IS FORECAST NORTHWEST OF ALASKA. THE ENSEMBLE SPAGHETTI CHARTS  
DEPICT LOW SPREAD OVER THE CONUS AND LOW TO MODERATE SPREAD OVER THE EAST  
PACIFIC. TODAY'S 500-HPA BLEND CHART 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 CENTRAL AND SOUTHERN  
HIGH PLAINS, THE SOUTHEAST U.S., EXTREME 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, PARTS OF THE OHIO  
VALLEY AND THE NORTHEAST. ANOMALOUS NORTHERLY FLOW FAVORS BELOW NORMAL  
TEMPERATURES FOR SOUTHEASTERN MAINLAND ALASKA.  
 
THE BROAD TROUGH FORECAST OVER THE CONUS FAVORS ABOVE NORMAL PRECIPITATION FOR  
THE EASTERN HALF OF THE CONUS. THE EXPECTATION OF UPSLOPE FLOW ENHANCES  
PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR PARTS OF THE NORTHERN AND  
CENTRAL ROCKIES AND NORTHERN AND CENTRAL PLAINS. 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 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 15% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED  
ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF  
TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 25% 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  
GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS AND AMONG THE SURFACE TOOLS.  
 
8-14 DAY OUTLOOK FOR FEB 06 - 12 2018  
 
ENSEMBLE MEAN SOLUTIONS GENERALLY INDICATE HEIGHTS WILL RISE OVER THE CENTRAL  
CONUS BUT OTHERWISE LITTLE CHANGE IS EXPECTED TO THE OVERALL CIRCULATION  
PATTERN DURING WEEK-2 FROM THAT FORECAST FOR THE 6-10 DAY PERIOD. THE ENSEMBLE  
SPAGHETTI CHARTS INDICATE LOW 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 ABOVE NORMAL TEMPERATURES FOR  
MUCH OF THE WESTERN HALF OF THE CONUS AND THE FLORIDA PENINSULA. BELOW NORMAL  
HEIGHTS AND/OR COLD SURFACE HIGH PRESSURE TILT THE ODDS TO NEAR TO BELOW NORMAL  
TEMPERATURES FOR MUCH OF THE EASTERN HALF OF THE CONUS. ABOVE NORMAL HEIGHTS  
FAVOR ABOVE NORMAL TEMPERATURE FOR THE ALEUTIANS, SOUTHERN AND CENTRAL MAINLAND  
ALASKA, AND THE ALASKA PANHANDLE.  
 
THE TROUGH OVER THE NORTH-CENTRAL U.S. ENHANCES PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION FOR PARTS OF THE NORTHERN PLAINS, THE UPPER MISSISSIPPI VALLEY,  
THE GREAT LAKES, AND THE NORTHEAST. ABOVE NORMAL HEIGHTS AND/OR ANOMALOUS  
NORTH/NORTHWESTERLY FLOW FAVORS BELOW NORMAL PRECIPITATION FOR THE WESTERN  
THIRD OF THE CONUS AND FROM MUCH OF THE CENTRAL AND SOUTHERN PLAINS EASTWARD TO  
THE SOUTHEAST U.S.. 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, 20% OF TODAY'S GFS SUPERENSEMBLE 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: 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: Y. FAN  
 
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:  
19590113 - 19560112 - 19510122 - 19540126 - 19680112  
 
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:  
19590113 - 19510122 - 19560113 - 19540125 - 19530125  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 04 - 08 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 B A WYOMING A A  
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 B A OKLAHOMA B B  
N TEXAS N B S TEXAS N A W TEXAS A B  
MINNESOTA B A IOWA B A MISSOURI B A  
ARKANSAS B A LOUISIANA N A WISCONSIN B A  
ILLINOIS B A MISSISSIPPI N A MICHIGAN B A  
INDIANA B A OHIO B A KENTUCKY B A  
TENNESSEE B A ALABAMA N A NEW YORK B A  
VERMONT B A NEW HAMP B A MAINE B A  
MASS B A CONN B A RHODE IS B A  
PENN B A NEW JERSEY B A W VIRGINIA B A  
MARYLAND B A DELAWARE B A VIRGINIA B A  
N CAROLINA B A S CAROLINA N A GEORGIA A A  
FL PNHDL A A FL PENIN A N AK N SLOPE N B  
AK ALEUTIAN A A AK WESTERN A B AK INT BSN N B  
AK S INT N A AK SO COAST B A AK PNHDL B A  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 06 - 12 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 N E MONTANA A A WYOMING A N  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA B A S DAKOTA A A  
NEBRASKA A N KANSAS A B OKLAHOMA N B  
N TEXAS N B S TEXAS B N W TEXAS A B  
MINNESOTA B A IOWA B N MISSOURI B B  
ARKANSAS B B LOUISIANA B B WISCONSIN B A  
ILLINOIS B B MISSISSIPPI B B MICHIGAN B A  
INDIANA B N OHIO B N KENTUCKY B B  
TENNESSEE B B ALABAMA B B NEW YORK B N  
VERMONT B N NEW HAMP B N MAINE B A  
MASS B N CONN B N RHODE IS B N  
PENN B N NEW JERSEY B N W VIRGINIA B N  
MARYLAND B N DELAWARE B N VIRGINIA B N  
N CAROLINA B B S CAROLINA B B GEORGIA B B  
FL PNHDL N N FL PENIN A N AK N SLOPE N B  
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.  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page