256 FEUS40 KWBC 291907 EONUS 6- TO 10-DAY OUTLOOK FOR OCT 5 - 9 2000 CLIMATE PREDICTION CENTER NCEP NATIONAL WEATHER SERVICE WASHINGTON DC 3 PM EDT FRI SEP 29 2000 THE NATIONAL WEATHER SERVICE 6 TO 10 DAY OUTLOOK FOR THURSDAY OCT 5 TO MONDAY OCT 9 2000 CALLS FOR BELOW NORMAL TEMPERATURES FROM EASTERN IDAHO AND MONTANA EASTWARD ACROSS MOST OF WYOMING TO NORTH DAKOTA AND NORTHERN SOUTH DAKOTA AND THEN EASTWARD AND SOUTHEASTWARD THROUGH THE UPPER MISSISSIPPI VALLEY...THE GREAT LAKES REGION...AND MOST OF THE OHIO VALLEY...AS WELL AS OVER FLORIDA AND MOST OF GEORGIA AND SOUTH CAROLINA. BELOW NORMAL TEMPERATURES ARE ALSO EXPECTED ACROSS EASTERN ALASKA INCLUDING ALL OF THE PANHANDLE. ABOVE NORMAL MEAN TEMPERATURES ARE EXPECTED FROM MOST OF SOUTHERN AND INTERIOR CENTRAL CALIFORNIA EASTWARD THROUGH THE SOUTHWESTERN HALF OF NEVADA...EXTREME SOUTHERN SECTIONS OF UTAH AND COLORADO...ARIZONA... NEW MEXICO...TEXAS...AND LOUISIANA...AS WELL AS OVER MOST OF MAINE. ABOVE NORMAL MEAN TEMPERATURES ARE ALSO EXPECTED FOR APPROXIMATELY THE WESTERN THIRD OF ALASKA. MUCH ABOVE NORMAL TEMPERATURES ARE INDICATED FOR SOUTHEASTERN ARIZONA... MOST OF NEW MEXICO...AND EXTREME SOUTHWESTERN TEXAS. NEAR NORMAL TEMPERATURES ARE INDICATED FOR UNSPECIFIED AREAS. LITTLE OR NO PRECIPITATION IS EXPECTED WEST OF THE CONTINENTAL DIVIDE EXCEPT FOR ABOVE MEDIAN TOTALS ALONG THE SOUTHERN CALIFORNIA COAST. LITTLE OR NO PRECIPITATION IS ALSO EXPECTED FROM SOUTHERN NEW MEXICO EASTWARD ACROSS MOST OF TEXAS AND THEN NORTHEASTWARD THROUGH MOST OF OKLAHOMA TO THE EASTERN HALF OF KANSAS...NORTHWESTERN MISSOURI... ARKANSAS...EXTREME NORTHERN LOUISIANA...KENTUCKY...TENNESSEE...NORTHERN PORTIONS OF MISSISSIPPI AND ALABAMA...SOUTHERN WEST VIRGINIA...AND WESTERN PORTIONS OF VIRGINIA AND NORTH CAROLINA. BELOW MEDIAN PRECIPITATION TOTALS ARE PREDICTED IN A BAND EXTENDING FROM THE SOUTHEASTERN TWO THIRDS OF MISSOURI THROUGH SOUTHERN PORTIONS OF ILLINOIS - INDIANA AND OHIO TO NORTHERN WEST VIRGINIA...WESTERN MARYLAND...AND NORTHERN VIRGINIA. ABOVE MEDIAN PRECIPITATION TOTALS ARE INDICATED OVER THE WESTERN PLAINS FROM EASTERN MONTANA SOUTH-SOUTHEASTWARD TO NORTHEASTERN NEW MEXICO AND THE OKLAHOMA PANHANDLE REGION AS WELL AS OVER THE FLORIDA PENINSULA AND COASTAL PORTIONS OF GEORGIA AND SOUTH CAROLINA...AND ALONG THE SOUTHERN CALIFORNIA COAST. ABOVE MEDIAN PRECIPITATION TOTALS ARE ALSO INDICATED FOR WESTERN ALASKA AND THE COOK INLET REGION...AND OVER THE SOUTHERN TIP OF THE ALASKAN PANHANDLE. NEAR MEDIAN PRECIPITATION IS EXPECTED IN UNSPECIFIED AREAS. STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N NP OREGON N NP NRN CALIF N NP SRN CALIF A NP IDAHO N NP NEVADA A NP W MONTANA B N E MONTANA B A WYOMING B A UTAH N NP ARIZONA A NP COLORADO N A NEW MEXICO MA NP N DAKOTA N N S DAKOTA N N NEBRASKA N A KANSAS N NP OKLAHOMA N NP N TEXAS A NP S TEXAS A N W TEXAS A NP MINNESOTA B N IOWA N N MISSOURI N B ARKANSAS N NP LOUISIANA A N WISCONSIN B N ILLINOIS B N MISSISSIPPI N N MICHIGAN B N INDIANA B B OHIO B N KENTUCKY B NP TENNESSEE N NP ALABAMA N N NEW YORK N N VERMONT N N NEW HAMP N N MAINE A N MASS N N CONN N N RHODE ISL N N PENN N N NEW JERSEY N N W VIRGINIA B B MARYLAND N N DELAWARE N N VIRGINIA N B N CAROLINA N N S CAROLINA B N GEORGIA B N FL PNHDL B N FL PENIN B A AK N SLOPE N N AK ALEUTIAN A N AK WESTERN A A AK INT BSN N N AK S INT N A AK S COAST N N AK PNHDL B N LEGEND TEMPS WITH RESPECT TO NORMAL PCPN WITH RESPECT TO MEDIAN MA - MUCH ABOVE A - ABOVE A - ABOVE N - NEAR MEDIAN N - NEAR NORMAL B - BELOW B - BELOW NP- NO PCPN MB - MUCH 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 - ON AFOS AS NFDPMDMRD. FORECASTER - R. MARTIN NOTE: THE NEXT 30- AND 90-DAY OUTLOOKS WILL BE ISSUED THURSDAY OCTOBER 12 2000 NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE On October 2 2000 - CPC will begin daily issuance of operational 6-10 day and 8-14 day temperature and precipitation outlooks in a probabilistic format. Operational ensembles of forecasts from the MRF model make this change possible. Computing technology that allows automated production and dissemination - on the one hand - but permits intervention by the forecaster - on the other hand - has made this feasible. With this change we are greatly increasing our service to users of our outlooks by: - Increasing the information content of the 6-10 day outlook through the use of a probabilistic format - Adding a new operational outlook for 8-14 days - Increasing the frequency of the 6-10 day outlook to daily while maintaining accuracy of the forecasts. The forecasts will be expressed in 3 categories Above normal - Near normal and Below normal - which are equally likely at any given location based on thirty years of data for any given calendar forecast period. The total probability will be shown. This means the 33.33% contour forms a boundary separating Near normal - on one side - from either Above normal or Below normal - on the other side. The 33.33% contour will be drawn thicker than the others. When the 33.33% contour lies between Near normal and Below - it and all the contours on the Below side of the line will be colored blue. When the 33.33% contour separates Near normal and Above - it and all the contours on the Above side of the line will be colored red. Near normal contours will be colored green. To further clarify the map - the letters B - N and A will mark the highest values of the favored category on the map. Because the climatological likelihood of each category is 33.33% - when the total probability of the A or B category exceeds 66.67% - the likelihood of the opposite category approaches zero - while the likelihood of extreme values increases. Regions where probabilities exceed 66.67% on the new outlook maps will often correspond closely to areas of much above or much below normal categories on the old outlook maps. In the Southwest and other climatologically dry regions- there will be a greater than 33.33% 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 light blue dashed contours on the map are the climatological normal (30 year average) temperature and precipitation totals for the forecast period - expressed in degrees Fahrenheit and tenths of inches - respectively. A single text bulletin (NMCPMDMRD FXUS06 KWBC) will accompany both the 6-10 day and 8-14 day outlooks. Two tables of U.S. State forecasts - one for the 6-10 day one for the 8-14 day outlook - will appear in the body of the bulletin. On Saturday and Sunday - the tables only will appear in the bulletin. Likewise - on weekend days the forecasts will be fully automated and objective - while on weekdays forecasters may intervene in the content of the forecast maps. Also on weekdays - the bulletin will contain a prognostic discussion of the 6-10 and 8-14 day outlooks written by the forecaster. A sample of a set of 6-10 day maps in the new format may be viewed at: http://www.cpc.ncep.noaa.gov/products/predictions/experimental /automated_products/610day.html NNNNN NNNNN