768  
FXUS06 KWBC 052033  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST MON FEBRUARY 05 2018  
 
6-10 DAY OUTLOOK FOR FEB 11 - 15 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/NORTHEAST OF HUDSON BAY, EXTENDING SOUTHWARD OVER THE  
SOUTHWEST CONUS LEADING TO A BROADLY CYCLONIC FLOW PATTERN ACROSS MOST OF THE  
CONUS. A RIDGE IS PREDICTED OVER THE EAST PACIFIC, WHILE A TROUGH IS FORECAST  
OVER THE ALEUTIANS. A SUBTROPICAL RIDGE IS FORECAST TO BE CENTERED OVER FLORIDA  
AND THE SOUTHERN GULF OF MEXICO. THE ENSEMBLE SPAGHETTI CHARTS INDICATE  
MODERATE SPREAD OVER THE EASTERN CONUS, AND LARGE SPREAD OVER THE WESTERN CONUS  
AND EASTERN PACIFIC. 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 NORTHERN PARTS  
OF ALASKA, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED OVER THE  
REMAINDER OF THE FORECAST DOMAIN.  
 
ABOVE NORMAL HEIGHTS FAVOR NEAR TO ABOVE NORMAL TEMPERATURES FOR MUCH OF THE  
WESTERN AND EASTERN CONUS. SURFACE ARCTIC HIGH PRESSURE EARLY IN THE PERIOD  
ENHANCES PROBABILITIES OF BELOW NORMAL TEMPERATURES FOR MUCH OF THE CENTRAL  
CONUS. ANOMALOUS SOUTHERLY FLOW TILTS THE ODDS TO ABOVE NORMAL TEMPERATURES FOR  
ALASKA.  
 
THE BROAD TROUGH FORECAST OVER THE CONUS ENHANCES PROBABILITIES OF NEAR TO  
ABOVE NORMAL PRECIPITATION OVER THE EASTERN CONUS AND PARTS OF THE SOUTHERN  
PLAINS. UPSLOPE FLOW TILTS THE ODDS FOR NEAR TO ABOVE NORMAL PRECIPITATION FOR  
MONTANA. THE TROUGH OVER THE ALEUTIANS FAVORS ABOVE NORMAL PRECIPITATION FOR  
ALASKA. THE RIDGE UPSTREAM OVER THE NORTHEAST PACIFIC TILTS THE ODDS TO NEAR TO  
BELOW NORMAL PRECIPITATION FOR THE REMAINDER OF THE CONUS.  
 
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 YESTERDAY'S OPERATIONAL 0Z ECMWF  
CENTERED ON DAY 7, 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: ABOUT AVERAGE, 3 OUT OF 5, DUE TO  
GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY LARGE DIFFERENCES  
AMONG THE TEMPERATURE TOOLS.  
 
8-14 DAY OUTLOOK FOR FEB 13 - 19 2018  
 
THE MEAN 500-HPA FLOW PATTERN EXPECTED FOR THE WEEK-2 PERIOD IS FORECAST TO  
BECOME MORE ZONAL AT THE MID TO HIGH LATITUDES WITH A SUBTROPICAL RIDGE  
REMANNING OVER FLORIDA. 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,  
SOUTHERN ALASKA, WHILE NEAR TO BELOW NORMAL HEIGHTS ARE ANTICIPATED OVER  
NORTHERN ALASKA.  
 
ABOVE NORMAL HEIGHTS FAVOR NEAR TO ABOVE NORMAL TEMPERATURES FOR MUCH OF THE  
CONUS. ANOMALOUS SOUTHERLY FLOW ENHANCES PROBABILITIES OF NEAR TO ABOVE NORMAL  
TEMPERATURES FOR ALASKA CONSISTENT WITH CALIBRATED GEFS AND ECMWF GUIDANCE.  
 
A SHORTWAVE TROUGH IN THE SOUTHERN JET STREAM AND RETURN FLOW FROM THE GULF OF  
MEXICO ENHANCE PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR PARTS OF WESTERN  
TEXAS. SPRAWLING SURFACE HIGH PRESSURE AND FAST PROGRESSIVE FLOW FAVOR NEAR TO  
BELOW NORMAL PRECIPITATION FOR THE REMAINDER OF THE CONUS. THE TROUGH OVER THE  
ALEUTIANS TILTS THE ODDS TO ABOVE NORMAL PRECIPITATION FOR 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: 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: 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:  
19840119 - 19630122 - 20050116 - 19630116 - 19620204  
 
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:  
19840119 - 19630122 - 19630117 - 19510131 - 19620203  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 11 - 15 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON N B OREGON A B NRN CALIF A B  
SRN CALIF A B IDAHO N B NEVADA A B  
W MONTANA B N E MONTANA B N WYOMING B N  
UTAH A B ARIZONA A N COLORADO B N  
NEW MEXICO N N N DAKOTA B N S DAKOTA B B  
NEBRASKA B B KANSAS B N OKLAHOMA B N  
N TEXAS B A S TEXAS B A W TEXAS B A  
MINNESOTA B N IOWA B N MISSOURI B N  
ARKANSAS B A LOUISIANA N A WISCONSIN B N  
ILLINOIS B N MISSISSIPPI A A MICHIGAN B N  
INDIANA N N OHIO N A KENTUCKY N A  
TENNESSEE A A ALABAMA A A NEW YORK A A  
VERMONT A A NEW HAMP A A MAINE A A  
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 A A  
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 13 - 19 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 B E MONTANA N N WYOMING N B  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A N N DAKOTA N N S DAKOTA N B  
NEBRASKA N B KANSAS N B OKLAHOMA N B  
N TEXAS N B S TEXAS N N W TEXAS A N  
MINNESOTA N N IOWA N B MISSOURI N B  
ARKANSAS N B LOUISIANA N B WISCONSIN N N  
ILLINOIS N B MISSISSIPPI A B MICHIGAN N N  
INDIANA N B OHIO N B KENTUCKY A B  
TENNESSEE A B ALABAMA A B NEW YORK A N  
VERMONT A A NEW HAMP A A MAINE A A  
MASS A A CONN A A RHODE IS A A  
PENN N N NEW JERSEY A N W VIRGINIA A N  
MARYLAND A N DELAWARE A N VIRGINIA A N  
N CAROLINA A N S CAROLINA A N GEORGIA A N  
FL PNHDL A N FL PENIN A N AK N SLOPE A A  
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  
 
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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