155  
FXUS06 KWBC 262001  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST FRI JANUARY 26 2018  
 
6-10 DAY OUTLOOK FOR FEB 01 - 05 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 MUCH OF THE CONUS. RIDGES ARE PREDICTED OVER  
THE EAST PACIFIC APPROACHING THE NORTH AMERICAN WEST COAT, AND THE CARIBBEAN,  
WHILE A TROUGH IS EXPECTED OVER NORTHERN HUDSON BAY. A STRONG CLOSED-OFF RIDGE  
IS FORECAST NORTHWEST OF ALASKA. A WEAK TROUGH IS FORECAST OVER ALASKA BETWEEN  
THE RIDGE FORECAST OVER THE EAST PACIFIC AND THE CLOSED-OFF RIDGE EXPECTED  
NORTHWEST OF THE STATE. THE ENSEMBLE SPAGHETTI CHARTS DEPICT LOW TO MODERATE  
SPREAD OVER THE CONUS AND MODERATE TO LARGE SPREAD OVER THE EAST PACIFIC. THE  
AO INDEX WHICH RECENTLY HAS BEEN CLOSE TO ZERO IS FORECAST TO BE WEAKLY  
NEGATIVE AT DAY 7 AND BECOME MORE STRONGLY NEGATIVE BY DAY 14. THE PNA INDEX  
WHICH RECENTLY HAS BEEN WEAKLY NEGATIVE IS FORECAST TO REMAIN WEAKLY NEGATIVE  
AT DAY 7, BE CLOSE TO ZERO AT DAY 10, AND BE POSITIVE BY DAY 14. 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 THE EASTERN, SOUTHERN, AND SOUTHWESTERN CONUS, EXTREME WESTERN  
MAINLAND ALASKA AND THE ALEUTIANS. NEAR TO BELOW NORMAL HEIGHTS TILT THE ODDS  
TO NEAR TO BELOW NORMAL TEMPERATURES FOR THE REMAINDER OF THE CONUS. ARCTIC  
HIGH PRESSURE IS LIKELY TO SHIFT SOUTHEAST FROM WESTERN CANADA, STRONGLY  
FAVORING BELOW NORMAL TEMPERATURES FOR THE NORTHERN PLAINS AND UPPER  
MISSISSIPPI VALLEY. ANOMALOUS NORTHERLY FLOW FAVORS BELOW NORMAL TEMPERATURES  
FOR SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE.  
 
THE BROAD TROUGH FORECAST OVER THE CONUS FAVORS ABOVE NORMAL PRECIPITATION FOR  
THE EASTERN THIRD OF THE NATION. 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 THE ALEUTIANS. ABOVE NORMAL  
HEIGHTS AND/OR ANOMALOUS NORTHWESTERLY FLOW FAVORS NEAR TO BELOW NORMAL  
PRECIPITATION FOR THE REMAINDER OF THE CONUS AND ALASKA.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 5% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 5% OF TODAY'S  
OPERATIONAL 6Z GFS CENTERED ON DAY 8, 25% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN  
CENTERED ON DAY 8, AND 25% OF YESTERDAY'S 12Z EUROPEAN 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 03 - 09 2018  
 
ENSEMBLE MEAN SOLUTIONS GENERALLY INDICATE HEIGHTS WILL RISE OVER THE  
SOUTH-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 TO MODERATE SPREAD OVER THE EASTERN  
CONUS, AND MODERATE TO LARGE SPREAD OVER THE WESTERN CONUS AND EASTERN PACIFIC.  
TODAY'S 500-HPA BLENDED HEIGHT CHART IS QUITE SIMILAR TO THAT FORECAST DURING  
THE 6-10 DAY PERIOD ALTHOUGH DURING WEEK-2 HEIGHTS ARE EXPECTED TO RISE  
SOMEWHAT OVER THE CENTRAL CONUS. 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  
PARTS OF THE SOUTHEASTERN AND SOUTHWESTERN CONUS. BELOW NORMAL HEIGHTS AND/OR  
COLD SURFACE HIGH PRESSURE TILT THE ODDS TO NEAR TO BELOW NORMAL TEMPERATURES  
FOR MUCH OF THE CENTRAL CONUS AND PARTS OF THE PACIFIC NORTHWEST, NORTHERN  
INTERMOUNTAIN WEST, AND NORTHERN ROCKIES. ABOVE NORMAL HEIGHTS FAVOR ABOVE  
NORMAL TEMPERATURE FOR THE ALEUTIANS AND WESTERN AND CENTRAL MAINLAND ALASKA.  
ANOMALOUS NORTHERLY FLOW ENHANCES PROBABILITIES FOR BELOW NORMAL TEMPERATURES  
FOR THE ALASKA PANHANDLE.  
 
THE TROUGH OVER THE CENTRAL U.S. ENHANCES PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION FOR MUCH OF THE EAST-CENTRAL AND EASTERN CONUS. UPSLOPE FLOW  
TILTS THE ODDS TO ABOVE NORMAL PRECIPITATION FOR PORTIONS OF THE NORTHERN  
ROCKIES AND NORTHERN AND CENTRAL PLAINS. ABOVE NORMAL HEIGHTS AND/OR ANOMALOUS  
NORTH/NORTHWESTERLY FLOW FAVORS BELOW NORMAL PRECIPITATION FOR PARTS OF THE  
WESTERN AND SOUTHWESTERN CONUS. ANOMALOUS NORTHERLY FLOW AND/OR ABOVE NORMAL  
HEIGHTS TILT THE ODDS TO BELOW NORMAL PRECIPITATION FOR NORTHERN AND EASTERN  
MAINLAND ALASKA AND THE ALASKA PANHANDLE, WHILE ANOMALOUS SOUTHEASTERLY FLOW  
ENHANCES PROBABILITIES FOR ABOVE NORMAL PRECIPITATION FOR THE ALEUTIANS AND  
PARTS OF SOUTHWESTERN MAINLAND ALASKA.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 15% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 15% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 25% OF  
TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF YESTERDAY'S 12Z  
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, AND 10% 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 MODEL SOLUTIONS AND MODERATE TO HIGH SPREAD  
AMONG ENSEMBLE MEMBERS OVER PARTS 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:  
19990128 - 19590107 - 19850209 - 20000111 - 19680115  
 
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:  
20000113 - 19590106 - 19560105 - 19680113 - 19990128  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 01 - 05 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B B OREGON N B NRN CALIF A B  
SRN CALIF A B IDAHO B N NEVADA A B  
W MONTANA B A E MONTANA B A WYOMING B A  
UTAH A B ARIZONA A B COLORADO B N  
NEW MEXICO A B N DAKOTA B N S DAKOTA B N  
NEBRASKA B N KANSAS B B OKLAHOMA B B  
N TEXAS B N S TEXAS N N W TEXAS B B  
MINNESOTA B N IOWA B N MISSOURI B N  
ARKANSAS B A LOUISIANA N A WISCONSIN B N  
ILLINOIS B A MISSISSIPPI B A MICHIGAN B N  
INDIANA B A OHIO B A KENTUCKY B A  
TENNESSEE B A ALABAMA N A NEW YORK N A  
VERMONT N 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 N A  
N CAROLINA N A S CAROLINA N A GEORGIA N A  
FL PNHDL N A FL PENIN A A AK N SLOPE N B  
AK ALEUTIAN A A AK WESTERN A B AK INT BSN N B  
AK S INT N B AK SO COAST N B AK PNHDL B B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 03 - 09 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B B OREGON A B NRN CALIF A B  
SRN CALIF A B IDAHO A N NEVADA A B  
W MONTANA B A E MONTANA B A WYOMING N A  
UTAH A B ARIZONA A B COLORADO A N  
NEW MEXICO A B N DAKOTA B N S DAKOTA B A  
NEBRASKA B A KANSAS B N OKLAHOMA B N  
N TEXAS B N S TEXAS N N W TEXAS N B  
MINNESOTA B N IOWA B N MISSOURI B A  
ARKANSAS B A LOUISIANA N A WISCONSIN B A  
ILLINOIS B A MISSISSIPPI B 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 N A S CAROLINA N A GEORGIA N A  
FL PNHDL A A FL PENIN A A AK N SLOPE A B  
AK ALEUTIAN A A AK WESTERN A N AK INT BSN A N  
AK S INT A N AK SO COAST A N AK PNHDL B B  
 
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