Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2
000
FXUS06 KWBC 281900
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON JULY 28 2014

6-10 DAY OUTLOOK FOR AUG 03 - 07 2014

TODAY`S GEFS, ECMWF, AND CANADIAN MODEL ENSEMBLE SOLUTIONS ARE IN EXCELLENT
AGREEMENT ON THE 6-10 DAY MEAN 500-HPA HEIGHTS OVER NORTH AMERICA AND VICINITY.
THE MODELS CONTINUE TO PREDICT A PERSISTING LONG-WAVE 500-HPA PATTERN OF AN
AMPLIFIED TROUGH OVER THE EAST-CENTRAL CONUS, CENTERED OVER THE GREAT LAKES AND
EXTENDING TO THE GULF COAST NEAR THE LOWER MISSISSIPPI VALLEY. AN AMPLIFIED
RIDGE IS PREDICTED OVER THE NORTHERN ROCKY MOUNTAINS INTO WEST-CENTRAL CANADA.
A TROUGH IS FORECAST OVER THE GULF OF ALASKA, HOWEVER, MUCH OF ALASKA IS TO THE
NORTH OF THE TROUGH, WITH 500-HPA HEIGHTS PREDICTED TO BE NEAR TO ABOVE NORMAL
AHEAD OF A RIDGE TO THE WEST OF THE STATE.

THE CHANCES OF BELOW-NORMAL TEMPERATURES ARE SIGNIFICANTLY ENHANCED FOR MUCH OF
THE EASTERN AND CENTRAL CONUS NEAR THE ANOMALOUSLY AMPLIFIED EASTERN TROUGH.
PROBABILITIES ARE HIGHEST NEAR AND TO THE NORTH OF AN EXPECTED FRONTAL
BOUNDARY, WHERE PRECIPITATION MAY HELP SUPPRESS DAYTIME TEMPERATURES.
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR THE FAR WESTERN CONUS NEAR THE UPPER
LEVEL RIDGE.  A FAIRLY STRONG GRADIENT IN TEMPERATURE ANOMALIES IS EXPECTED
JUST WEST OF THE ROCKIES, LEADING TO HIGH UNCERTAINTY IN TEMPERATURES FOR THE
INTERMOUNTAIN WEST.  MEAN TEMPERATURES IN ALASKA ARE FAIRLY UNCERTAIN SINCE
TEMPERATURES WILL DEPEND ON THE STRENGTH OF THE TROUGH FORECAST TO BE OVER THE
GULF OF ALASKA.  TOOLS BASED ON UPPER LEVEL HEIGHTS FAVOR BELOW-NORMAL
TEMPERATURES, WHILE THOSE BASED ON LOW LEVEL TEMPERATURES FROM THE MODELS FAVOR
WARM CONDITIONS. ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR WESTERN ALASKA NEAR
A FAIRLY STRONG RIDGE EXPECTED JUST TO THE WEST OF THE STATE, WITH NEAR-NORMAL
TEMPERATURES FAVORED IN PARTS OF EASTERN ALASKA.

THE PRECIPITATION OUTLOOK FAVORS ABOVE-MEDIAN RAINFALL AMOUNTS ALONG AN
EXPECTED MEAN FRONTAL BOUNDARY THAT EXTENDS FROM THE CENTRAL ROCKIES TO THE
GULF COAST AND THEN ALONG THE EASTERN SEABOARD. BEHIND THE MEAN FRONTAL
BOUNDARY, COOL AND RELATIVELY DRY AIR FOR THE SEASON IS EXPECTED TO ENHANCE
CHANCES FOR BELOW-MEDIAN PRECIPITATION AMOUNTS FOR MUCH OF THE EAST-CENTRAL
CONUS. NAEFS AND THE GEFS REFORECAST TOOL SHOW ENHANCED CHANCES OF ABOVE-MEDIAN
PRECIPITATION AMOUNTS IN PARTS OF THE INTERMOUNTAIN WEST, WITH BELOW-MEDIAN
PRECIPITATION FAVORED NEAR THE PACIFIC NORTHWEST COAST.  ABOVE-MEDIAN
PRECIPITATION IS EXPECTED FOR SOUTHEASTERN ALASKA, AHEAD OF THE EXPECTED
TROUGH, WITH THE RELATIVELY DRY CONDITIONS FAVORED FOR THE WESTERN AND CENTRAL
PARTS OF THE STATE.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 40 PERCENT OF TODAY`S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8...10 PERCENT OF TODAY`S OPERATIONAL 0Z ECMWF
CENTERED ON DAY 8...30 PERCENT OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 8...AND 20 PERCENT OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8.

MODEL OF THE DAY: TODAY`S 6Z GEFS ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: WELL ABOVE AVERAGE, 5 OUT OF 5,
DUE TO EXCELLENT AGREEMENT AMONG TODAY`S MODELS AND TOOLS.

8-14 DAY OUTLOOK FOR AUG 05 - 11 2014

THE ANOMALY PATTERN FOR THE FORECAST 500-HPA HEIGHTS OVER THE CONUS AND
SOUTHERN CANADA REMAINS SIMILAR TO THE 6-10 DAY MEAN. A SUBSTANTIAL FRACTION OF
MODEL ENSEMBLE MEMBERS CONTINUE TO PREDICT AN AMPLIFIED EASTERN TROUGH, WITH
MOST MEMBERS RELAXING THE STRENGTH OF THE WESTERN RIDGE, LEADING TO A
DISTINCTLY LOWER AMPLITUDE IN THE PREDICTED 8-10 DAY MEAN 500-HPA FLOW PATTERN
WHEN COMPARED TO THE 6-10 DAY PERIOD. THE 500-HPA HEIGHT PATTERN OVER ALASKA IS
SUBSTANTIALLY CHANGED BETWEEN THE TWO PERIODS, WITH THE TROUGH OVER THE GULF OF
ALASKA THAT WAS FORECAST FOR THE 6-10 DAY PERIOD VIRTUALLY ABSENT IN THE
WEEK-TWO FORECAST.

THE TEMPERATURE AND PRECIPITATION OUTLOOK FOR THE CONUS FOR WEEK-TWO IS QUITE
SIMILAR TO THE 6-10 DAY PERIOD, WITH LOWER PROBABILITIES FOR ANOMALIES
REFLECTING THE GREATER SPREAD AMONG SOLUTIONS AND THE EXPECTED LOWER AMPLITUDE
FLOW PATTERN. TOOLS GENERALLY FAVOR ABOVE-NORMAL TEMPERATURES FOR MOST OF
ALASKA, WITH NEAR TO BELOW-MEDIAN PRECIPITATION AMOUNTS EXPECTED AS THE CHANCES
OF TROUGH OVER GULF OF ALASKA IS EXPECTED TO DIMINISH BETWEEN THE 6-10 AND 8-14
DAY PERIOD.


THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 40 PERCENT OF TODAY`S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11...30 PERCENT OF TODAY`S 0Z EUROPEAN ENSEMBLE
MEAN CENTERED ON DAY 11...AND 30 PERCENT OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 11.

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOVE AVERAGE, 4 OUT OF 5, DUE
TO GOOD AGREEMENT AMONG THE MODELS AND TOOLS.

FORECASTER: DAVE UNGER

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
AUGUST 21

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:
19620721 - 20080808 - 19670711 - 19890717 - 19650726


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:
19620722 - 19600708 - 19670710 - 20080808 - 19650725


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 03 - 07 2014

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    B     OREGON      A    N     NRN CALIF   A    N
SRN CALIF   A    N     IDAHO       A    A     NEVADA      A    A
W MONTANA   A    N     E MONTANA   A    N     WYOMING     B    A
UTAH        N    A     ARIZONA     N    A     COLORADO    B    A
NEW MEXICO  B    A     N DAKOTA    N    B     S DAKOTA    B    B
NEBRASKA    B    B     KANSAS      B    B     OKLAHOMA    B    N
N TEXAS     B    A     S TEXAS     B    A     W TEXAS     B    A
MINNESOTA   B    B     IOWA        B    B     MISSOURI    B    B
ARKANSAS    B    B     LOUISIANA   B    N     WISCONSIN   B    B
ILLINOIS    B    B     MISSISSIPPI B    B     MICHIGAN    B    B
INDIANA     B    B     OHIO        B    N     KENTUCKY    B    N
TENNESSEE   B    N     ALABAMA     B    N     NEW YORK    N    A
VERMONT     N    A     NEW HAMP    N    A     MAINE       A    N
MASS        N    A     CONN        N    A     RHODE IS    N    A
PENN        B    A     NEW JERSEY  B    A     W VIRGINIA  B    A
MARYLAND    B    A     DELAWARE    B    A     VIRGINIA    B    A
N CAROLINA  B    A     S CAROLINA  B    A     GEORGIA     B    A
FL PNHDL    B    A     FL PENIN    N    A     AK N SLOPE  A    B
AK ALEUTIAN A    B     AK WESTERN  A    B     AK INT BSN  A    B
AK S INT    A    N     AK SO COAST A    B     AK PNHDL    A    B



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 05 - 11 2014

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    B     OREGON      A    N     NRN CALIF   A    N
SRN CALIF   A    N     IDAHO       N    A     NEVADA      A    N
W MONTANA   N    A     E MONTANA   N    N     WYOMING     B    A
UTAH        N    A     ARIZONA     A    A     COLORADO    B    A
NEW MEXICO  B    A     N DAKOTA    N    B     S DAKOTA    B    N
NEBRASKA    B    N     KANSAS      B    N     OKLAHOMA    B    A
N TEXAS     B    A     S TEXAS     N    A     W TEXAS     B    A
MINNESOTA   N    B     IOWA        B    B     MISSOURI    B    N
ARKANSAS    B    A     LOUISIANA   B    A     WISCONSIN   N    B
ILLINOIS    B    N     MISSISSIPPI B    A     MICHIGAN    N    N
INDIANA     B    N     OHIO        B    A     KENTUCKY    B    A
TENNESSEE   B    A     ALABAMA     B    A     NEW YORK    N    N
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    B
MASS        N    N     CONN        N    N     RHODE IS    N    N
PENN        N    N     NEW JERSEY  N    N     W VIRGINIA  B    A
MARYLAND    N    N     DELAWARE    N    N     VIRGINIA    B    A
N CAROLINA  B    A     S CAROLINA  B    A     GEORGIA     B    N
FL PNHDL    B    N     FL PENIN    N    B     AK N SLOPE  A    N
AK ALEUTIAN A    N     AK WESTERN  A    B     AK INT BSN  A    N
AK S INT    A    B     AK SO COAST A    B     AK PNHDL    A    N

                           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.

$$



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.