664
FXUS06 KWBC 121912
PMDMRD
PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT TUE AUG 12 2008
6-10 DAY OUTLOOK VALID FOR AUG 18 - 22 2008
TODAYS DYNAMICAL MODEL SOLUTIONS REMAIN IN GOOD AGREEMENT ON THE PREDICTED FLOW
PATTERN OVER THE NORTH AMERICAN REGION DURING THE 6-10 DAY FORECAST PERIOD. ALL
AVAILABLE ENSEMBLE MEAN SOLUTIONS CONTINUE TO INDICATE A TROUGH AT UPPER LEVELS
OVER THE BERING SEA AND GULF OF ALASKA, A DOWNSTREAM RIDGE OVER THE NORTHERN
HIGH PLAINS, AND A TROUGH OVER THE CENTRAL STATES OR EASTERN HALF OF THE CONUS.
THE GFS RUNS APPEAR TO UNDERESTIMATE THE HEIGHTS OVER SOUTHERN CANADA, SO
SLIGHTLY MORE WEIGHT IS GIVEN TO THE CANADIAN MODEL, WHICH HAS BEEN DEPICTING
HIGHER HEIGHTS IN THAT REGION. THE ECMWF MODEL HAS ALSO BEEN SHOWING HIGHER
HEIGHTS ACROSS SOUTHERN CANADA, AND THIS MODEL HAS BEEN INCORPORATED INTO THE
HEIGHT BLEND TO SLANT THE FINAL BLEND SLIGHTLY TOWARD THIS RESULT. EVEN WITHOUT
REGARD TO THE EVENTUAL TRACK OF FUTURE TROPICAL CYCLONES, THE UPPER AIR PATTERN
FAVORS WIDESPREAD RAIN OVER THE EAST, WITH PLENTIFUL MOISTURE FEEDING IN FROM
THE TROPICAL GULF AND ATLANTIC. THE TROPICAL PREDICTION CENTER INDICATES A HIGH
RISK FOR TROPICAL CYCLONE DEVELOPMENT FROM THE DISTURBED AREA A FEW HUNDRED
MILES EAST OF THE LESSER ANTILLES, WITH A MODERATE RISK FOR DEVELOPMENT FROM
THE CLUSTER OF THUNDERSTORMS A FEW HUNDRED MILES EAST OF THE FIRST DISTURBANCE.
LOOKING FARTHER AHEAD, AN IMPRESSIVE TROPICAL WAVE IS BRINGING RAIN TO THE MALI
AREA OF AFRICA. THE LARGE-SCALE PATTERN OF UPPER-LEVEL DIVERGENCE IS MOVING
INTO THE ATLANTIC FROM THE WEST, AND THIS FAVORS TROPICAL ACTIVITY FOR THE NEXT
2 TO 3 WEEKS. WITH THE FIRST TROPICAL DISTURBANCE, IT IS TOO SOON TO TALK ABOUT
SPECIFIC TRACKS AND INTENSITY, BUT THE CONSENSUS OF THE MODEL RUNS IS THAT THIS
FEATURE SHOULD ENHANCE THE ODDS FOR HEAVY RAINS ACROSS SOUTHERN FLORIDA BY
MONDAY, AND THIS IS REFLECTED IN A LARGER PROBABILITY FOR RAINFALL IN BOTH THE
6-10 DAY AND 8-14 DAY FORECASTS. THE LOCATION OF HEAVY RAINS FARTHER NORTH IS
VERY DIFFICULT TO DETERMINE, WITH THE LATEST GFS RUN SHOWING ENOUGH ATLANTIC
RIDGING TO KEEP THE BULK OF THE RAINS WEST OF THE SOUTHEAST COASTAL STATES. THE
CURRENT 6-10 DAY FORECAST FAVORS EARLIER ENSEMBLE FORECASTS THAT FOCUS THE
RAINS OVER THE SOUTHEAST AND NORTHWARD INTO NEW ENGLAND.
TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S OPERATIONAL
ECMWF CENTERED ON DAY 7...35 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED
ON DAY 8...40 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8...AND
15 PERCENT OF TODAY'S EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7.
MODEL(S) OF THE DAY: CANADIAN ENSEMBLE.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS ABOVE AVERAGE, 4 ON A SCALE OF 1
TO 5, DUE TO GOOD MODEL AGREEMENT AND FAIRLY GOOD AGREEMENT AMONG THE TOOLS.
THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE
OFFICIAL BLEND, THE AUTO TEMPERATURE FORECAST, AND NORTH AMERICAN ENSEMBLE
FORECAST SYSTEM (NAEFS) TEMPERATURE PROBABILITY FORECASTS.
THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE
OFFICIAL BLEND, THE AUTO PRECIPITATION FORECAST, NORTH AMERICAN ENSEMBLE
FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY FORECASTS, AND THE DAILY
FORECASTS FROM THE MOST RECENT GFS RUNS.
8-14 DAY OUTLOOK FOR AUG 20 - 26 2008:
THE FORECAST UPPER AIR PATTERN SHOWS LITTLE CHANGE FROM THE 6-10 DAY PATTERN
AND YESTERDAY'S FORECAST. A LINGERING TROUGH PERSISTS OVER THE EAST IN THE
MEAN, WITH WEAK RIDGING TO THE WEST AND NORTH. A WET OUTLOOK CONTINUES FOR THE
EAST, WITH TROPICAL WEATHER SYSTEMS A GOOD BET TO ENHANCE THE RAINFALL TOTALS,
ESPECIALLY OVER FLORIDA. ONE CHANGE FROM THE PREVIOUS FORECAST IS THE ADDITION
OF AN AREA OF ABOVE-NORMAL RAINS IN THE NORTHERN PLAINS. THIS COMES OUT OF BOTH
THE ANALOG FORECAST AND THE LATEST 12Z GFS MODEL RUN.
THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 45 PERCENT OF TODAY'S GFS
SUPERENSEMBLE MEAN CENTERED ON DAY 11...AND 55 PERCENT OF TODAY'S CANADIAN
ENSEMBLE MEAN CENTERED ON DAY 11.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS ABOUT AVERAGE, 3 ON A SCALE OF 1
TO 5.
THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE
OFFICIAL BLEND, THE AUTO TEMPERATURE FORECAST, AND NORTH AMERICAN ENSEMBLE
FORECAST SYSTEM (NAEFS) TEMPERATURE PROBABILITY FORECASTS.
THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE
OFFICIAL BLEND, NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) PRECIPITATION
PROBABILITY FORECASTS, AND DAILY WEATHER FROM THE MOST RECENT GFS MODEL RUNS.
FORECASTER: LE COMTE
NOTES:
OPERATIONAL CHANGE: AS OF JULY 5 2005 SHADED MAPS HAVE REPLACED THE
CONTOUR-ONLY MAPS ON THE CPC WEB SITE. THE CONTOURED MAPS ARE
STILL AVAILABLE AT THEIR CURRENT FILE NAMES - SO DIRECT-LINKED USERS
ARE NOT AFFECTED. AWIPS GRAPHICS ARE ALSO NOT AFFECTED BY THIS
CHANGE.
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.
THE CLIMATE PREDICTION CENTER USES 1971-2000 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
AUGUST 21.
NEW NOTE EFFECTIVE MAR 16 2004:
THE GLOSSARY FORMERLY FOUND AT THIS LOCATION WILL NO LONGER BE
TRANSMITTED AS PART OF THIS MESSAGE. IF YOU WISH TO SEE THE
DEFINITIONS OF TERMS USED IN THESE MESSAGES... PLEASE GO TO THE
CPC WEB PAGE AT (USE LOWER CASE) HTTP://WWW.CPC.NCEP.NOAA.GOV
AND FOLLOW THE APPROPRIATE LINKS.
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:
19680826 - 19910806 - 19640816 - 19530818 - 19570725
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 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
19910805 - 19640815 - 19530818 - 19570725 - 19570731
6 TO 10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 18 - 22, 2008
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N 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 N N
UTAH N N ARIZONA N N COLORADO B N
NEW MEXICO B N N DAKOTA A B S DAKOTA N B
NEBRASKA B N KANSAS B N OKLAHOMA B A
N TEXAS B A S TEXAS N N W TEXAS B N
MINNESOTA A B IOWA B B MISSOURI B N
ARKANSAS B A LOUISIANA B A WISCONSIN N N
ILLINOIS B N MISSISSIPPI B A MICHIGAN N N
INDIANA N A OHIO N A KENTUCKY N A
TENNESSEE B A ALABAMA B 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 N A NEW JERSEY N A W VIRGINIA N 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 N A AK N SLOPE N B
AK ALEUTIAN B N AK WESTERN A B AK INT BSN N N
AK S INT B A AK SO COAST B A AK PNHDL B A
8 TO 14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 20 - 26, 2008
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON A N NRN CALIF A B
SRN CALIF A B IDAHO N N NEVADA A N
W MONTANA N N E MONTANA A N WYOMING N N
UTAH N N ARIZONA A N COLORADO B N
NEW MEXICO N A N DAKOTA A A S DAKOTA N A
NEBRASKA B N KANSAS B N OKLAHOMA B N
N TEXAS B A S TEXAS N N W TEXAS N N
MINNESOTA A A IOWA N N MISSOURI B A
ARKANSAS B A LOUISIANA B A WISCONSIN N N
ILLINOIS B N MISSISSIPPI B A MICHIGAN N N
INDIANA N A OHIO N A KENTUCKY N A
TENNESSEE N A ALABAMA N A NEW YORK N A
VERMONT A A NEW HAMP A A MAINE A A
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA N 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 N A AK N SLOPE N N
AK ALEUTIAN B A AK WESTERN B N AK INT BSN N N
AK S INT N A AK SO COAST B A AK PNHDL B 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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