Prognostic Meteorological Discussion
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FXUS06 KWBC 192001
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 19 2018

6-10 DAY OUTLOOK FOR FEB 25 - MAR 01, 2018

TODAY`S ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT ON THE EXPECTED 500-HPA
FLOW PATTERN OVER THE FORECAST DOMAIN. A DEEP TROUGH IS FORECAST NORTHWEST OF
HUDSON BAY EXTENDING EAST/SOUTHEAST OVER THE NORTH ATLANTIC, AND SOUTHWESTWARD
OVER THE WESTERN CONUS. RIDGES ARE ANTICIPATED OVER THE GULF OF MEXICO AND
WESTERN MAINLAND ALASKA. THE FLOW PATTERN IS PREDICTED TO BE RELATIVELY
AMPLIFIED. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE SMALL TO MODERATE SPREAD
ACROSS THE MAJORITY OF THE FORECAST DOMAIN. 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 ABOVE NORMAL HEIGHTS
OVER MOST OF THE EASTERN CONUS, THE SOUTHERN PLAINS, THE ALEUTIANS, AND
SOUTHWESTERN MAINLAND ALASKA, AND NEAR TO BELOW NORMAL HEIGHTS OVER MUCH OF THE
WESTERN CONUS, THE NORTHERN PLAINS,  NORTHEASTERN MAINLAND ALASKA, AND THE
ALASKA PANHANDLE.

PERSISTENT TROUGHING IN THE WESTERN CONUS LEADS TO INCREASED CHANCES FOR BELOW
NORMAL TEMPERATURES FOR MUCH OF THE WESTERN AND NORTH-CENTRAL CONUS. A STRONG
RIDGE FORECAST OVER THE SOUTHEASTERN U.S. LEADS TO ENHANCED CHANCES OF ABOVE
NORMAL TEMPERATURES FOR THE EASTERN CONUS AND THE SOUTHERN PLAINS. ANOMALOUS
RIDGING OVER SOUTHWESTERN ALASKA FAVORS NEAR TO ABOVE NORMAL TEMPERATURES FOR
MUCH OF WESTERN AND NORTHERN MAINLAND ALASKA AS WELL AS THE ALEUTIANS.
ANOMALOUS NORTHERLY FLOW TILTS THE ODDS TO NEAR TO BELOW NORMAL TEMPERATURES
FOR SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE.

THE DEEP TROUGH FORECAST OVER THE WESTERN CONUS AND/OR ANOMALOUS SOUTHWESTERLY
FLOW ENHANCE PROBABILITIES OF NEAR TO ABOVE NORMAL PRECIPITATION OVER PARTS OF
THE SOUTHERN PLAINS, AND MOST OF THE EASTERN CONUS, EXCEPT FOR FLORIDA WHERE
BELOW NORMAL PRECIPITATION IS INDICATED DUE TO THE HIGHLY ANOMALOUS SOUTHEAST
RIDGE. BELOW NORMAL PRECIPITATION IS ALSO FAVORED FOR PARTS OF THE HIGH PLAINS,
AND THE CENTRAL AND SOUTHERN ROCKIES, CONSISTENT WITH DYNAMICAL MODEL GUIDANCE
FROM THE ECMWF ENSEMBLE MEAN SOLUTIONS. BELOW NORMAL HEIGHTS TILT THE ODDS TO
NEAR TO ABOVE NORMAL PRECIPITATION FOR THE WESTERN CONUS. SURFACE LOW PRESSURE
OVER THE EASTERN GULF OF ALASKA FAVORS ABOVE NORMAL PRECIPITATION FOR MUCH OF
ALASKA.

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 TODAY`S OPERATIONAL 0Z ECMWF CENTERED
ON DAY 8, 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE MODELS AND FORECAST TOOLS.

8-14 DAY OUTLOOK FOR FEB 27 - MAR 05, 2018

THE MEAN 500-HPA FLOW PATTERN EXPECTED FOR THE WEEK-2 PERIOD IS SIMILAR TO THAT
DEPICTED FOR THE 6 TO 10 DAY TIME FRAME, ALTHOUGH SLIGHTLY LESS AMPLIFIED
CIRCULATION FEATURES ARE INDICATED AND THE OVERALL LONG WAVE PATTERN IS SHIFTED
A BIT WESTWARD. ABOVE NORMAL HEIGHTS ARE EXPECTED OVER MOST OF THE EASTERN
CONUS, MAINLAND ALASKA, AND THE ALEUTIANS, WHILE BELOW NORMAL HEIGHTS ARE
ANTICIPATED OVER THE WESTERN CONUS, AND THE SOUTHERN ALASKA PANHANDLE.

THE WEEK-2 TEMPERATURE PROBABILITY FORECAST IS VERY SIMILAR TO THE 6-10 DAY
FORECAST, EXCEPT SLIGHTLY LOWER PROBABILITIES DUE TO THE TYPICALLY INCREASED
UNCERTAINTY IN THE WEEK-2 PERIOD, AND A GENERAL WESTWARD DISPLACEMENT OF THE
TEMPERATURE ANOMALY PATTERN DUE TO AN EXPECTED RETROGRESSION OF THE OVERALL
LONG WAVE HEIGHT PATTERN.

THE BROAD TROUGH FORECAST OVER THE WESTERN CONUS ENHANCES PROBABILITIES OF NEAR
TO ABOVE NORMAL PRECIPITATION OVER PARTS OF THE HIGH PLAINS AND MISSISSIPPI
VALLEY AREA. ABOVE NORMAL HEIGHTS TILT THE ODDS TO NEAR TO BELOW NORMAL
PRECIPITATION FOR PARTS OF THE EASTERN GREAT LAKES, THE OHIO VALLEY, THE MIDDLE
ATLANTIC, THE NORTHEAST, AND FLORIDA. BELOW NORMAL PRECIPITATION IS ALSO
FAVORED FOR COLORADO, CONSISTENT WITH DYNAMICAL MODEL GUIDANCE FROM THE ECMWF
ENSEMBLE MEAN SOLUTIONS. BELOW NORMAL HEIGHTS TILT THE ODDS TO NEAR TO ABOVE
NORMAL PRECIPITATION FOR PARTS OF THE UTAH, ARIZONA, NEVADA, AND CALIFORNIA.
SURFACE LOW PRESSURE OVER THE EASTERN GULF OF ALASKA FAVORS ABOVE NORMAL
PRECIPITATION FOR MUCH OF ALASKA.

THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY`S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 10% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 11, 30% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF
YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, 10% OF TODAY`S 0Z
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 10% OF YESTERDAY`S 12Z CANADIAN
ENSEMBLE MEAN CENTERED ON DAY 10


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

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
MARCH 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:
19590205 - 19890213 - 19570130 - 19550224 - 19660214


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:
19590205 - 19570202 - 19890201 - 19890212 - 19550224


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR FEB 25 - MAR 01, 2018

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    A
SRN CALIF   B    A     IDAHO       B    A     NEVADA      B    A
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    N
UTAH        B    A     ARIZONA     B    A     COLORADO    B    B
NEW MEXICO  B    N     N DAKOTA    B    N     S DAKOTA    B    B
NEBRASKA    B    B     KANSAS      N    N     OKLAHOMA    A    A
N TEXAS     A    A     S TEXAS     A    A     W TEXAS     N    N
MINNESOTA   N    N     IOWA        A    A     MISSOURI    A    A
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   A    A
ILLINOIS    A    A     MISSISSIPPI A    A     MICHIGAN    A    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    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    N
FL PNHDL    A    B     FL PENIN    A    B     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  N    A
AK S INT    B    A     AK SO COAST B    A     AK PNHDL    B    N



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR FEB 27 - MAR 05, 2018

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

$$




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