PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EST TUE MAR 2 2004 6 TO 10 DAY OUTLOOK FOR MAR 8 - MAR 12 2004 . . . . . . . THE MAIN HIGH RESOLUTION FORECAST MODELS ARE IN REASONABLE AGREEMENT ON THE LONG WAVE 500 HPA PATTERN OVER NORTH AMERICA FOR THE FIRST FOUR DAYS...BUT DIFFERENCES IN PHASING DEVELOP BY DAY 5 WITH THE TWO MOST RECENT UKMET RUNS AND THE CANADIAN MODEL BEING SOMEWHAT LESS PROGRESSIVE THAN THE ECMWF...NOGAPS...AND THE OZ AND 6Z GFS RUNS. THE GFS ENSEMBLE MEMBERS ALSO SHOW SUCH A BIMODAL DISTRIBUTION OF EASTWARD PROGRESSION OF THE MAIN FEATURES...BUT THE FASTER SOLUTION PREDOMINATES SO THAT THE GFS ENSEMBLE MEAN IS JUST SLIGHTLY SLOWER THAN THE 0Z GFS BY THE START OF THE 6 TO 10 DAY PERIOD. THIS IS VERY MUCH LIKE THE DIFFERENCE BETWEEN THE ECMWF...WHICH IS PHASED LIKE THE 0Z GFS ON DAY 6...AND THE ECMWF ENSEMBLE MEAN WHICH AGREES REASONABLY WELL WITH THE GFS ENSEMBLE MEAN ON DAY 6. ON THE WHOLE THE MODELS FORECAST A DEAMPLIFYING AND PROGRESSIVE FLOW DURING THE FIRST FIVE DAYS...WITH THE MEAN TROUGH MOVING FROM OVER THE WESTERN STATES TO OVER THE EASTERN STATES...WHILE A RIDGE BUILDS ALONG THE WEST COAST. FOR THE 6 TO 10 DAY PERIOD ALL THE MODEL AND ENSEMBLE MEANS ARE IN REASONABLE AGREEMENT ON THE LARGE SCALE 500 HPA MEAN FLOW PATTERN AGAIN TODAY...WITH A RIDGE CENTERED OVER THE WEST COAST OF NORTH AMERICA...A BROAD TROUGH OVER EASTERN NORTH AMERICA...AND AN ARCTIC VORTEX CENTERED IN THE GENERAL VICINITY OF THE CANADIAN ARCHIPELAGO. SOME SOLUTIONS HAVE A RATHER FLAT WESTERN RIDGE WHILE OTHERS... ESPECIALLY THE ECMWF AND ECMWF ENSEMBLE MEAN...HAVE A MORE AMPLIFIED RIDGE. THERE IS LESS SPLIT-FLOW THAN HAS BEEN OBSERVED RECENTLY BUT A WEAK SPLIT-FLOW PATTERN IS STILL APPARENT OFF THE WEST COAST IN SOME SOLUTIONS...ESPECIALLY IN THE OPERATIONAL ECMWF AND 12Z AND 18Z GFS SOLUTIONS. ONE SLIGHT DIFFERENCE AMONG THE SOLUTIONS IS THAT THE ECMWF ENSEMBLE MEAN BREAKS A BAND OF WEAK POSITIVE HEIGHT ANOMALIES THROUGH FROM SOUTHERN GREENLAND TO SOUTH-CENTRAL CANADA WHILE THE GFS-BASED SOLUTIONS HAVE A BAND OF WEAK NEGATIVE HEIGHT ANOMALIES BREAKING THROUGH FROM NORTHWESTERN CANADA TO THE NEGATIVE ANOMALY CENTER OVER THE EASTERN U.S. THE CANADIAN ENSEMBLE MEAN RESEMBLES THE ECMWF ENSEMBLE MEAN IN THIS RESPECT WHILE THE OPERATIONAL ECMWF LOOKS MORE LIKE YESTERDAYS GFS RUNS IN KEEPING MODERATE NEGATIVE HEIGHT ANOMALIES OVER EASTERN CANADA. ANOTHER DIFFERENCE AMONG TODAYS SOLUTIONS IS THE ECMWF AND ECMWF ENSEMBLE MEAN HAVE A BAND OF NEGATIVE HEIGHT ANOMALIES AT MIDDLE LATITUDES ACROSS THE ATLANTIC WHERE OTHER SOLUTIONS HAVE POSITIVE ANOMALIES...ALTHOUGH THE 12Z GFS COMPROMISES AND HAS A MIXTURE OF ANOMALIES IN THIS AREA. A MEAN TROUGH AND BELOW NORMAL HEIGHTS ARE FORECAST FOR ALASKA BY ALL MODELS...BUT THE TROUGH AXIS IS FAR ENOUGH WEST IN THE ECMWF AND ECMWF ENSEMBLE MEAN THAT THERE MAY BE ENOUGH SOUTHERLY FLOW OVER THE STATE TO KEEP THE TEMPERATURE FROM BEING BELOW NORMAL IN MANY LOCATIONS. HOWEVER SLIGHT PHASE DIFFERENCES IN THE MODELS CAN LEAD TO LARGE DIFFERENCES FOR A REGION AS SMALL (ON A GLOBAL SCALE) AS ALASKA...AND THE SURFACE TEMPERATURES IMPLIED BY THE GFS-BASED SOLUTIONS WOULD BE SIGNIFICANTLY COLDER THAN THOSE FROM THE ECMWF- BASED HEIGHT FORECASTS. CONTINUITY WITH YESTERDAYS SOLUTIONS IS REASONABLE...AND THE DAILY GFS AND ECMWF ENSEMBLE MEANS ARE IN REASONABLE AGREEMENT DURING DAYS 6 THROUGH 10. THE SPREAD AMONG ENSEMBLE MEMBERS IS ABOUT TYPICAL... BUT EXAMINATION OF DAILY 0Z AND 6Z GFS RUNS AND THE GFS ENSEMBLE MEMBERS SHOWS THAT THE MEAN 500 HPA FIELD COMES FROM A PROGRESSIVE PATTERN OF MODERATELY LARGE AMPLITUDE WAVES. THIS MEANS THAT THE AVERAGE SURFACE CONDITIONS AT MANY LOCATIONS WILL COME FROM A WIDER VARIETY OF DAILY WEATHER THAN IS SOMETIMES THE CASE...WHICH INCREASES THE UNCERTAINTY OF THE MEAN OUTLOOK. TELECONNECTIONS FROM THE NEGATIVE HEIGHT ANOMALIES IN THE VICINITY OF 50N/170W WHICH MOST MODELS SHOW SUPPORT THE ECMWF ENSEMBLE MEANS IDEA OF THE BAND OF POSITIVE HEIGHT ANOMALIES ACROSS EASTERN CANADA. THE GFS ENSEMBLE MEAN FORECASTS THE NAO INDEX TO GO FROM NEGATIVE TO NEAR ZERO AND THE PNA INDEX ALSO TO GO FROM NEGATIVE TO NEAR ZERO TO POSITIVE DAY 10...IN LINE WITH THE IDEA OF DEAMPLIFYING FLOW AND RAPID TRANSITIONS. MODEL OF THE DAY: EUROPEAN ENSEMBLE MEAN DUE TO SUPERIOR ANOMALY CORRELATION SCORES DURING THE LAST 60 DAYS...PLUS SOMEWHAT BETTER TELECONNECTIVITY TODAY. THE OFFICIAL HEIGHT PROG FOR TODAY CONSISTS OF 40 PERCENT OF THE ECMWF ENSEMBLE MEAN CENTERED ON DAY 7...10 PERCENT OF THE 0Z GFS 5 DAY MEAN CENTERED ON DAY 8...10 PERCENT OF THE 6Z GFS 5 DAY MEAN CENTERED ON DAY 8...20 PERCENT OF THE GFS ENSEMBLE MEAN CENTERED ON DAY 8...AND 20 PERCENT OF THE CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8. FORECAST CONFIDENCE FOR THE 6 TO 10 DAY PERIOD IS CONSIDERED AVERAGE TODAY...3 ON A SCALE FROM 1 TO 5...DUE TO REASONABLE MODEL AGREEMENT BEING OFFSET BY THE PROGRESSIVE FLOW AND PATTERN TRANSITION BEING FORECAST. THE 6 TO 10 DAY TEMPERATURE PROG IS BASED ON KLEIN AND NEURAL NET SPECIFICATIONS FROM THE BLEND AND COMPOSITE ANALOGS FROM THE BLEND WITH SOME CONSIDERATION OF THE CDC CALIBRATED TEMPERATURES ALTHOUGH THESE DID NOT LOOK CONSISTENT WITH THE BLEND HEIGHT FIELD IN A NUMBER OF PLACES. THE 6 TO 10 DAY PRECIPITATION PROG IS BASED ON THE CDC CALIBRATED PRECIPITATION FORECAST...CALIBRATED PROBABILITIES FROM THE GFS ENSEMBLE MEMBERS...BIAS CORRECTED AND CALIBRATED PRECIPITATION FROM THE 0Z GFS...AND ANALOGS AND NEURAL NETS FROM THE BLEND. . . . . . . . 8 TO 14 DAY OUTLOOK FOR MAR 10 - MAR 16 2004 FOR THE 8 TO 14 DAY PERIOD...THE LATEST GFS RUNS AND GFS ENSEMBLE MEAN FORECAST A RETURN TO SPLIT FLOW WITH MEAN RIDGING OVER WESTERN CANADA AND WEAK MEAN TROUGHING OVER THE WESTERN U.S. WITH TROUGHING THROUGH EASTERN CANADA AND THE WESTERN ATLANTIC. THERE ARE DIFFERENCES IN THE DETAILS OF THE PATTERN FROM THE VARIOUS RUNS... BUT ALL HAVE ABOVE NORMAL 500 HPA ANOMALIES OVER ALMOST ALL THE LOWER 48 STATES...AND BELOW NORMAL HEIGHTS OVER ALASKA. DESPITE THE NEGATIVE HEIGHT ANOMALIES OVER ALASKA...ENOUGH SOUTHWESTERLY FLOW IS FORECAST THAT THE SOUTHEASTERN HALF OF THE STATE SHOULD REMAIN NEAR OR ABOVE NORMAL IN TEMPERATURE. THE OFFICIAL 500-HPA HEIGHT PROG FOR TODAY CONSISTS OF 80 PERCENT OF TODAYS GFS ENSEMBLE MEAN CENTERED ON DAY 11...AND 20 PERCENT OF YESTERDAYS GFS ENSEMBLE MEAN CENTERED ON DAY 10. FORECAST CONFIDENCE FOR THE 8 TO 14 DAY PERIOD IS BELOW AVERAGE TODAY...2 ON A SCALE FROM 1 TO 5. THE 8 TO 14 DAY TEMPERATURE PROG IS BASED ON KLEIN AND NEURAL NET SPECIFICATIONS FROM THE BLEND...AND ANALOGS FROM THE BLEND. THE CDC CALIBRATED TEMPERATURES APPEARED TO BE TOO COLD IN MANY PLACES GIVEN THE OFFICIAL 500 HPA HEIGHT FORECAST AND WERE DISCOUNTED. THE 8 TO 14 DAY PRECIPITATION PROG IS BASED ON THE CDC CALIBRATED PRECIPITATION FORECAST...CALIBRATED PROBABILITIES FROM THE GFS ENSEMBLE MEMBERS...CALIBRATED AND BIAS CORRECTED PRECIPITATION FROM THE 0Z GFS...AND ANALOGS AND NEURAL NETS FROM BLEND. THE PRECIPITATION TOOLS WERE BADLY SPLIT OVER HOW MUCH PRECIPITATION WILL OCCUR IN THE CENTER OF THE NATION. THE UPPER LEVEL PATTERN APPEARS TO SUPPORT LESS PRECIPITATION THAN EVEN BIAS CORRECTED AND CALIBRATED MODEL OUTPUTS SUGGEST. THE WETTER TOOLS WERE DISCOUNTED TODAY. FORECASTER: R. MARTIN . . . . . . . NOTES: AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OTHERWISE - FORECASTS INCORPORATE FORECASTER INPUT. 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 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 NARRATIVE DESCRIPTION OF THE FORECAST PATTERNS FOR TEMPERATURE AND PRECIPITATION FOR BOTH THE 6-10 OR 8-14 DAY PERIODS HAS BEEN DISCONTINUED. THE STATE TABLES FOR BOTH THE 6-10 AND 8-14 DAY PERIODS ARE NOW CONTAINED IN THIS MESSAGE...AVAILABLE AS PMDMRD ON AWIPS. EFFECTIVE THURSDAY MAY 17 2001...THE CLIMATE PREDICTION CENTER HAS SWITCHED TO 1971-2000 BASE PERIOD MEANS FOR TEMPERATURE... PRECIPITATION...AND 500-HPA HEIGHTS AS REFERENCE IN THE CLIMATE OUTLOOKS. THE 1971-2000 BASE PERIOD MEANS HAVE REPLACED THE 1961-1990 BASE PERIOD MEANS. . . . . . . . GLOSSARY AND DEFINITIONS:--------------------------------------------- AC - ANOMALY CORRELATION - A MEASURE OF HOW WELL A MODEL FORECASTS THE HEIGHT OR HEIGHT ANOMALY FIELD OBTAINED BY CORRELATING THE IMPLIED GRADIENTS OF THE TWO ANOMALY PATTERNS BEING COMPARED. ANALOG (NATURAL ANALOG) - A WEATHER MAP THAT RESEMBLES ANOTHER WEATHER MAP - USUALLY FROM DIFFERENT YEARS BUT THE SAME SEASON IN THE HISTORICAL RECORD. THE CRITERION FOR SELECTING AN ANALOG IS OFTEN THE PATTERN CORRELATION BETWEEN THE MAPS. TWO MAPS WILL JUST BEGIN TO RESEMBLE EACH OTHER TO THE HUMAN EYE AT A PATTERN CORRELATION OF ABOUT 40%. TO BE USEFUL - ANALOGS NEED TO HAVE MUCH HIGHER CORRELATIONS TO THE ORIGINAL MAP THAN THAT - 80% OR MORE. ANALOGS ARE INCREASINGLY DIFFICULT TO FIND AS THE GEOGRAPHIC REGION BEING STUDIED INCREASES IN SIZE. PERFECT ANALOGS TO THE ENTIRE NORTHERN HEMISPHERE SIMPLY DO NO EXIST - FOR PRACTICAL PURPOSES. THIS IS WHY SIMPLE NATURAL ANALOG FORECAST METHODS DO NOT WORK VERY WELL. ANOMALY - THE ARITHMETIC DIFFERENCE BETWEEN THE VALUE OF A VARIABLE AT A GIVEN PLACE AND TIME AND THE LONG-TERM AVERAGE OF THAT VARIABLE AT THAT PLACE AND TIME OF YEAR. AO - ARCTIC OSCILLATION - A MEASURE OF THE DIFFERENCE BETWEEN THE MEAN MID-TROPOSPHERIC HEIGHT OR SEA LEVEL PRESSURE ANOMALY OVER THE POLAR BASIN AND THE CORRESPONDING AVERAGE ANOMALY IN A RING SURROUNDING THE POLAR BASIN AT MIDDLE LATITUDES. THE AO IS CONSIDERED TO BE THE LEADING MODE OF CLIMATE VARIABILITY OF THE EXTRATROPICAL NORTHERN HEMISPHERE. THE AO CAN ALSO BE CONSIDERED TO INCLUDE THE NAO (NORTH ATLANTIC OSCILLATION) WITH WHICH IT IS POSITIVELY CORRELATED - BUT NOT IDENTICAL. THE PHASE OF THE AO IS CONSIDERED TO BE POSITIVE WHEN HEIGHTS OR PRESSURES ARE BELOW NORMAL OVER THE ARCTIC BASIN AND ABOVE NORMAL OVER SURROUNDING MID- LATITUDES - AND IS NEGATIVE FOR THE REVERSE ANOMALY PATTERN. BLEND - A WEIGHTED AVERAGE OF 500-HPA HEIGHT FORECAST MAPS FROM SEVERAL MODELS. WEIGHTS ARE CURRENTLY ASSIGNED SUBJECTIVELY BY THE FORECASTER. THE SUM OF THE WEIGHTS MUST BE 1. WEIGHTS ARE APPLIED BY MULTIPLYING EACH 500-HPA MAP BY ITS WEIGHT AND ADDING ALL OF THE WEIGHTED MAPS TOGETHER TO MAKE THE OFFICIAL 500-HPA FORECAST. CONUS - CONTERMINOUS UNITED STATES. DAVA - DIVERGENT ANOMALY VORTICITY ADVECTION MODEL. THIS IS A BAROTROPIC MODEL WITH DIVERGENCE IN IT TO ALLOW MORE ACCURATE PREDICTION OF LONG WAVES THAN A STANDARD BAROTROPIC MODEL. REFERENCE: QIN J. AND H.M. VAN DEN DOOL - 1996: SIMPLE EXTENSIONS OF AN NWP MODEL. MON. WEA. REV. - VOL 124 - PP 277-287. EL NINO - THE WARM PHASE OF ENSO. ENSO - EL NINO/SOUTHERN OSCILLATION. FLOW PATTERN - THE PATTERN OF WIND INFERRED BY THE 500-HPA CONTOURS - THE WIND TENDS TO BLOW PARALLEL TO THE CONTOURS WITH LOW HEIGHT ON THE LEFT - IN THE NORTHERN HEMISPHERE - THE OPPOSITE IS TRUE IN THE SOUTHERN HEMISPHERE. WIND SPEED IS INVERSELY PROPORTIONAL TO THE SPACING BETWEEN THE CONTOURS. GFS - GLOBAL FORECAST SYSTEM. THIS REFERS TO ANY OF THE GLOBAL MODELS RUN AT NCEP FOUR TIMES A DAY THAT USED TO BE REFERRED TO AS THE MRF AND AVN MODELS. THE MODEL RUN INITIATED AT 00Z (00 GMT) IS CURRENTLY THE ONLY ONE USED BY CPC IN ITS OFFICIAL BLEND FORECAST - ALTHOUGH THE OTHERS CAN BE CONSIDERED BY THE FORECASTER IN FORMULATING THE TEMPERATURE AND PRECIPITATION FORECASTS. GFS ENSEMBLE - A SET OF GFS FORECASTS WHICH ARE ALL VALID AT THE SAME TIME BUT WHOSE STARTING CONDITIONS DIFFER BY SMALL AMOUNTS. THERE ARE CURRENTLY 25 MEMBERS IN THE GFS ENSEMBLE. THE AVERAGE OF THESE IS THE GFS ENSEMBLE MEAN. 500-HPA HEIGHT IS THE HEIGHT - IN METERS - ABOVE MEAN SEA LEVEL - WHICH ABOUT HALF OF THE MASS OF THE ATMOSPHERE LIES ABOVE AND BELOW - AS MEASURED BY THE PRESSURE. UPPER AIR STORM SYSTEMS TEND TO BE STEERED IN THE DIRECTION OF THE WINDS AT 500-HPA. 500-HPA SYSTEMS CORRELATE STRONGLY WITH SURFACE WEATHER. HPA - HECTO-PASCALS. 1 HPA = 1 MILLIBAR. LA NINA - THE COLD PHASE OF ENSO. MERIDIONAL FLOW PATTERN - OCCURS WHEN 500-HPA CONTOURS EXHIBIT LARGE NORTHWARD AND SOUTHWARD EXCURSIONS WITH EXTENSIVE AREAS OF SOUTHERLY AND NORTHERLY FLOW. MODEL BIAS - THE DIFFERENCE BETWEEN THE MODEL CLIMATOLOGY AND THE OBSERVED CLIMATOLOGY - EXPRESSED AS BIAS = MODEL CLIMO - OBSERVED CLIMO. MODEL OF THE DAY - FOR 6-10 DAYS - IS THE MODEL WHOSE SOLUTION IS CONSIDERED TO BE MORE RELIABLE THAN USUAL - AND MAY BE GIVEN HIGHER THAN TYPICAL WEIGHT IN THE BLEND. NO MODEL OF THE DAY IS CHOSEN FOR 8-14 DAYS. MOS - MODEL OUTPUT STATISTICS - A STATISTICAL TOOL FOR SPECIFYING THE SURFACE TEMPERATURE (AND ITS ANOMALY) FROM MODEL FIELDS - CORRECTING AUTOMATICALLY FOR BOTH BIASES IN THE MODEL FIELDS AND THE SPECIFICATION METHOD. IT IS VALID AS LONG AS A GIVEN CONFIGURATION OF A MODEL IS NOT CHANGED OR MODIFIED. MJO - MADDEN-JULIAN OSCILLATION - ALSO CALLED TROPICAL INTRA-SEASONAL OSCILLATION - A SERIES OF WAVES WITH A PERIOD AVERAGING 50 DAYS THAT MOVES SLOWLY EASTWARD NEAR THE EQUATOR ALTERNATELY ENHANCING AND SUPRESSING PRECIPITATION. NAO - NORTH ATLANTIC OSCILLATION TELECONNECTION PATTERN. IT CAN ALSO BE VIEWED AS THE ATLANTIC HALF OF THE AO (ARCTIC OSCILLATION) TELECONNECTION PATTERN - STRONGLY INFLUENCES TEMPERATURES OVER EUROPE AND MUCH OF NORTH AMERICA - ESPECIALLY DURING THE COLD SEASONS - AND DETERMINES THE MEAN LATITUDE OF THE PREVAILING STORM TRACKS ACROSS THE NORTH ATLANTIC. THE PHASE OF THE NAO IS CONSIDERED POSITIVE WHEN PRESSURES AND HEIGHTS ARE BELOW NORMAL OVER GREENLAND AND ICELAND (STRONG ICELANDIC LOW) AND ABOVE NORMAL AT MIDDLE AND SUBTROPICAL LATITUDES (STRONG BERMUDA-AZORES HIGH) - AND NEGATIVE FOR THE REVERSE ANOMALIES. PNA - PACIFIC NORTH AMERICAN TELECONNECTION PATTERN. PROG - PROGNOSIS - OR FORECAST. PROGRESSION OR PROGRESSIVE MOTION - THE NORMAL MOVEMENT OF ATMOSPHERIC WEATHER SYSTEMS (HIGHS... LOWS... RIDGES... OR TROUGHS) FROM WEST TO EAST IN THE MIDDLE LATITUDES. RETROGRESSION OR RETROGRADE MOTION - A TYPE OF MOTION SOMETIMES OBSERVED IN WEATHER SYSTEMS WHEN THEY END UP IN POSITIONS FURTHER TO THE WEST THAN THEIR ORIGINAL LOCATIONS - CONTRARY TO THEIR USUAL WEST TO EAST MOTION. RIDGE - A REGION OF UNUSUALLY HIGH 500-HPA HEIGHT. SHORT WAVES - RELATIVELY LOW-AMPLITUDE - FAST-MOVING DISTURBANCES OF THE 500-HPA FIELD. SOUTHERN STREAM - A FLOW PATTERN WITH UNUSUALLY STRONG FLOW ACROSS THE SOUTHERN U.S. - ACCOMPANIED BY UNUSUAL STORMINESS IN THE SOUTH AND SOUTHEAST. SPECIFICATIONS - KLEIN AND NEURAL NETWORK SPECIFICATIONS GIVE THE HISTORICAL RELATIONSHIP BETWEEN 500-HPA HEIGHT ANOMALIES AND SURFACE TEMPERATURE AND PRECIPITATION. KLEIN SPECIFICATIONS TEND TO EMPHASIZE REGIONAL TELECONNECTIONS WHILE THOSE FROM THE NEURAL NETWORK WORK FROM GLOBAL TELECONNECTIONS. . . . . . . . TELECONNECTIONS GIVE THE HISTORICAL RELATIONSHIP BETWEEN THE 500-HPA HEIGHT AT A GIVEN POINT AND ALL OTHER POINTS ON A MAP FOR A GIVEN TIME OF YEAR. WE AVERAGE THE TOP/BOTTOM 10% OF DAILY MAPS FROM 1950-1999 FOR THE SAME TIME OF YEAR HAVING THE HIGHEST/LOWEST 500-HPA HEIGHT AT THE SPECIFIED POINT. TROUGH - A REGION OF UNUSUALLY LOW 500-HPA HEIGHT. UTC - UNIVERSAL TIME COORDINATED - SAME AS GREENWICH MEAN TIME (GMT). WESTERLY WIND - WIND BLOWING FROM WEST TO EAST. EASTERLY WIND - WIND BLOWING FROM EAST TO WEST. NORTHERLY WIND - WIND BLOWING FROM NORTH TO SOUTH SOUTHERLY WIND - WIND BLOWING FROM SOUTH TO NORTH. ZONAL FLOW PATTERN - OCCURS WHEN 500-HPA CONTOURS LIE IN AN EAST-WEST DIRECTION PARALLEL TO LATITUDE CIRCLES WITH NEARLY PURE WEST-TO-EAST FLOW. ---------------------------------------------------------------------- THE NEXT MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON THURSDAY... MARCH 18TH. 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: 19790317 - 19580310 - 19870225 - 19870317 - 19960226 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: 19580310 - 19810226 - 19870225 - 19870316 - 19580313 6 to 10 day Outlook Table 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 N S DAKOTA A B NEBRASKA A B KANSAS A B OKLAHOMA A B N TEXAS N B S TEXAS N N W TEXAS A B MINNESOTA A N IOWA A B MISSOURI N B ARKANSAS N B LOUISIANA N N WISCONSIN A N ILLINOIS N B MISSISSIPPI N N MICHIGAN N N INDIANA N N OHIO N N KENTUCKY N N TENNESSEE N N ALABAMA N N NEW YORK N N VERMONT N A NEW HAMP N A MAINE N A MASS N A CONN N A RHODE IS N A PENN N N NEW JERSEY N N W VIRGINIA N N MARYLAND N N DELAWARE N N VIRGINIA N N N CAROLINA N N S CAROLINA N N GEORGIA B N FL PNHDL B N FL PENIN B N AK N SLOPE B B AK ALEUTIAN B B AK WESTERN B B AK INT BSN B N AK S INT N A AK SO COAST N A AK PNHDL A A 8 to 14 day Outlook Table 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 N N DAKOTA A N S DAKOTA A B NEBRASKA A B KANSAS A B OKLAHOMA A B N TEXAS A B S TEXAS N N W TEXAS A N MINNESOTA A N IOWA A N MISSOURI A B ARKANSAS A B LOUISIANA A N WISCONSIN A N ILLINOIS A B MISSISSIPPI A B MICHIGAN A N INDIANA A B OHIO A B KENTUCKY A B TENNESSEE A B ALABAMA N B NEW YORK A N VERMONT N N NEW HAMP A N MAINE A A MASS A N CONN A N RHODE IS A N PENN A N NEW JERSEY N N W VIRGINIA A B MARYLAND N N DELAWARE N N VIRGINIA N N N CAROLINA N N S CAROLINA N B GEORGIA N B FL PNHDL N N FL PENIN N N AK N SLOPE B B AK ALEUTIAN B N AK WESTERN B N AK INT BSN N N AK S INT N A AK SO COAST N 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. $$