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FXUS06 KWBC 241904
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU MAY 24 2018

6-10 DAY OUTLOOK FOR MAY 30 - JUN 03, 2018

TODAY`S 0Z GFS ENSEMBLE MEAN TRENDED TOWARD PRIOR RUNS OF THE ECMWF ENSEMBLE
MEAN WITH A MORE AMPLIFIED 500-HPA TROUGH ENTERING THE WESTERN U.S. BY THE END
OF MAY. DOWNSTREAM OF THIS UPPER-LEVEL TROUGH, HIGHLY ANOMALOUS RIDGING IS
LIKELY TO DEVELOP FROM THE RIO GRANDE NORTHEAST TO THE MIDDLE MISSISSIPPI
VALLEY. THE DETERMINISTIC 6Z AND 12Z GFS MODEL INDICATES 500-HPA HEIGHTS
INCREASING TO MORE THAN 594-DM ACROSS THE SOUTHERN GREAT PLAINS BY JUNE 1 WHICH
IS QUITE UNUSUAL FOR THIS TIME OF YEAR. BASED ON GOOD MODEL AGREEMENT AND
CONTINUITY ALONG WITH THE PREDICTED 500-HPA HEIGHT PATTERN AND LOW-LEVEL
THERMAL FIELDS, DAILY RECORD HIGHS ARE BECOMING MORE LIKELY DURING THIS PERIOD
ACROSS OKLAHOMA AND TEXAS. HIGH PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE
FORECAST ACROSS THE SOUTHERN GREAT PLAINS WHERE MAXIMUM TEMPERATURES ARE LIKELY
TO AVERAGE 15 TO 20 DEGREES F ABOVE NORMAL THROUGH AT LEAST DAY 7. ABOVE-NORMAL
TEMPERATURES ARE ALSO FAVORED THROUGHOUT THE REMAINDER OF THE CENTRAL AND
EASTERN U.S. UNDERNEATH AN AMPLIFIED RIDGE. HOWEVER, ANOMALOUS CLOUD COVER AND
RAINFALL TO BEGIN THE PERIOD REDUCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES
ACROSS THE SOUTHEAST.

TELECONNECTIONS UPON A PAIR OF 500-HPA HEIGHT ANOMALY CENTERS (NEAR JAMES BAY
AND OVER THE NORTHEAST PACIFIC) SUPPORT AN UPPER-LEVEL TROUGH MOVING INLAND
FROM THE WEST COAST DURING THIS PERIOD. THEREFORE, THE COVERAGE AND
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE REDUCED ACROSS THE WESTERN
CONUS. THE EXPECTATION OF A PERSISTENT, MARITIME LAYER TILT THE ODDS TO
BELOW-NORMAL TEMPERATURES ALONG MUCH OF COASTAL CALIFORNIA.

THE DETERMINISTIC 6Z GFS AND 0Z ECMWF MODEL RUNS ARE IN MUCH BETTER AGREEMENT
TODAY WITH THE EVOLUTION ON WHAT IS LIKELY TO BECOME AN EARLY SEASON TROPICAL
CYCLONE IN THE NORTHERN GULF OF MEXICO. THE REMNANT LOW OF THIS SYSTEM IS
FORECAST TO MOVE INLAND OF THE CENTRAL GULF COAST PRIOR TO DAY 6 AND THEN
BECOME A SURFACE TROUGH OF LOW PRESSURE. THESE FEATURES AND A CONTINUED INFLUX
OF ANOMALOUS LOW-LEVEL MOISTURE INCREASE CHANCES FOR ABOVE-NORMAL PRECIPITATION
FROM THE GULF COAST NORTH TO THE OHIO VALLEY AND MID-ATLANTIC. THE 0Z
DETERMINISTIC MODEL RUNS INDICATES 1 TO 3 INCHES OF RAINFALL ACROSS THE
SOUTHERN APPALACHIANS WHERE THE HIGHEST PROBABILITIES FOR ABOVE-NORMAL
PRECIPITATION ARE FORECAST.

SHORTWAVE TROUGHS, EMERGING FROM THE LONGWAVE TROUGH NEAR THE WEST COAST,
INCREASE CHANCES FOR ABOVE NORMAL PRECIPITATION FROM THE CENTRAL GREAT BASIN
EAST TO THE GREAT LAKES. RIDGING ALOFT IS LIKELY TO SUPPRESS CONVECTION ACROSS
THE SOUTHERN HALF OF THE GREAT PLAINS, WHILE RIDGING OVER THE NORTHERN PACIFIC
FAVORS BELOW NORMAL PRECIPITATION ACROSS THE PACIFIC NORTHWEST.

AN UPPER-LEVEL TROUGH OVER THE BERING SEA INCREASES CHANCES FOR ABOVE-NORMAL
PRECIPITATION ACROSS SOUTHWEST ALASKA AND THE ALEUTIANS, WHILE MEAN RIDGING
ALOFT TILTS THE ODDS TO BELOW-NORMAL PRECIPITATION ACROSS EASTERN MAINLAND
ALASKA. TEMPERATURE TOOLS DERIVED FROM THE DYNAMICAL MODELS SUPPORT
BELOW-NORMAL TEMPERATURES ACROSS THE SOUTHERN THIRD OF ALASKA, BUT ABOVE NORMAL
SEA SURFACE TEMPERATURES ARE EXPECTED TO FAVOR NEAR TO ABOVE NORMAL
TEMPERATURES ACROSS THE ALEUTIANS AND MUCH OF WESTERN COASTAL MAINLAND ALASKA.

THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY`S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, AND 60% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
IMPROVED MODEL AGREEMENT WITH THE FATE OF A LOW PRESSURE SYSTEM EMERGING FROM
THE GULF OF MEXICO AND THE AMPLITUDE OF AN UPPER-LEVEL TROUGH ENTERING THE
WESTERN U.S.

8-14 DAY OUTLOOK FOR JUN 01 - 07 2018

THE MODEL CONSENSUS INDICATES A LONGWAVE 500-HPA PATTERN MORE TYPICAL OF
MID-SUMMER THAN THE FIRST WEEK OF JUNE, ESPECIALLY ACROSS THE SOUTH-CENTRAL
CONUS. EARLY IN WEEK-2, THE ENSEMBLE MEANS AND THEIR DETERMINISTIC MODEL RUNS
INDICATE A HIGHLY ANOMALOUS RIDGE EXTENDING FROM NORTHERN MEXICO NORTHEAST TO
THE SOUTHERN GREAT PLAINS. THE DETERMINISTIC 6Z GFS MODEL INDICATES 500-HPA
HEIGHTS PEAKING AT 597DM, OR HIGHER, OVER THE TEXAS BIG BEND REGION DURING THE
FIRST DAYS OF JUNE. THEREFORE, HIGH PROBABILITIES FOR ABOVE NORMAL TEMPERATURES
ARE FORECAST ACROSS THE SOUTH-CENTRAL U.S. DURING WEEK-2. THE LONGWAVE TROUGH,
INITIALLY NEAR THE WEST COAST, IS EXPECTED TO BE A SOURCE FOR SHORTWAVE TROUGHS
THAT COULD FLATTEN THE RIDGE ALOFT ACROSS THE HIGHER LATITUDES OF THE CONUS.
COMPARED TO YESTERDAY`S OUTLOOK, PROBABILITIES FOR ABOVE NORMAL TEMPERATURES
ARE DECREASED ACROSS THE NORTHERN TIER. RECENT HEAVY RAINFALL AND AN
INCREASINGLY WET TOPSOIL DECREASE PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES
ACROSS THE EASTERN U.S., WHILE DRIER TOPSOILS CONTINUE TO CONTRIBUTE TO HIGHER
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ACROSS THE CENTRAL AND SOUTHERN
GREAT PLAINS.

THE MOST CONFIDENCE IN THE PRECIPITATION OUTLOOK, ALBEIT STILL RATHER LOW,
EXISTS ACROSS THE SOUTHERN APPALACHIANS WHERE HEAVY RAIN MAY LINGER INTO THE
BEGINNING OF WEEK-2. ALSO, RIDGING ALOFT AND THE EXPECTATION OF A STRONG
CAPPING INVERSION ARE LIKELY TO SUPPRESS CONVECTION AND RESULT IN BELOW NORMAL
PRECIPITATION ACROSS THE SOUTHERN GREAT PLAINS. ELSEWHERE, PRECIPITATION
SIGNALS AMONG THE TOOLS ARE WEAK WHICH IS TYPICAL WHEN PRECIPITATION IS MORE
CONVECTIVE. ONE NOTABLE CHANGE IS A DRIER PATTERN FOR THE FLORIDA PENINSULA AS
ANOMALOUS, MOIST FLOW IS EXPECTED TO EASE.

THE UPPER-LEVEL TROUGH OVER THE BERING SEA TILTS THE ODDS TO ABOVE NORMAL
PRECIPITATION ACROSS THE ALEUTIANS AND WESTERN MAINLAND ALASKA, WHILE AN
UPPER-LEVEL RIDGE INCREASES CHANCES FOR BELOW NORMAL PRECIPITATION ACROSS
EASTERN MAINLAND ALASKA. THE TEMPERATURE OUTLOOK IS BASED ON DYNAMICAL MODEL
CONSENSUS AND SEA SURFACE ANOMALY CONSIDERATIONS.

THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY`S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, AND 75% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
MORE UNCERTAINTY IN THE TEMPERATURE OUTLOOK ACROSS THE NORTH-CENTRAL U.S. AND
LOW PREDICTABILITY IN THE PRECIPITATION OUTLOOK INHERENT DURING THE CONVECTIVE
SEASON.

FORECASTER: BRAD PUGH

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
JUNE 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:
19910513 - 19610603 - 19950602 - 19530506 - 19610519


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:
19910513 - 19610604 - 19950601 - 19860529 - 19530506


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 30 - JUN 03, 2018

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUN 01 - 07 2018

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